View Filing Data

Print Document View Excel Document

Document and Entity Information	12 Months Ended
Document and Entity Information	Dec. 31, 2018 shares
Document and Entity Information [Abstract]
Entity Registrant Name	AC Immune SA
Entity Central Index Key	0001651625
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Filer Category	Accelerated Filer
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Common Stock, Shares Outstanding	67,562,333
Document Type	20-F
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	FY

Balance Sheets SFr in Thousands, $ in Thousands	Dec. 31, 2018 CHF (SFr)	Dec. 31, 2017 CHF (SFr)
Non-current assets
Property, plant and equipment	SFr 3,324	SFr 2,353
Long-term financial assets	304	126
Total non-current assets	3,628	2,479
Current assets
Prepaid expenses	2,364	1,440
Accrued income	3,667	2,799
Finance receivable	199	0
Other current receivables	236	918
Short-term financial assets	30,000	0
Cash and cash equivalents	156,462	124,377
Total current assets	192,928	129,534
Total assets	196,556	132,013
Shareholders' equity
Share capital	1,351	1,147
Share premium	298,149	188,299
Accumulated losses	(121,877)	(72,607)
Total shareholders' equity	177,623	116,839
Non-current liabilities
Long-term debt obligation	186	494
Net employee defined benefit liabilities	5,665	4,926
Total non-current liabilities	5,851	5,420
Current liabilities
Trade and other payables	1,979	1,092
Accrued expenses	10,420	8,307
Deferred income	351	355
Short-term debt obligation	332	0
Total current liabilities	13,082	9,754
Total liabilities	18,933	15,174
Total shareholders' equity and liabilities	SFr 196,556	SFr 132,013

Statements of Loss - CHF (SFr) SFr in Thousands	12 Months Ended
Statements of Loss - CHF (SFr) SFr in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues
Contract revenue	SFr 7,194	SFr 20,255	SFr 23,214
Total revenue	7,194	20,255	23,214
Operating expenses
Research & development expenses	(44,277)	(32,663)	(25,774)
General & administrative expenses	(12,467)	(10,131)	(7,896)
Total operating expenses	(56,744)	(42,794)	(33,670)
Operating loss	(49,550)	(22,539)	(10,456)
Finance income / (expense), net	(1,132)	(4,055)	3,324
Interest income	29	330	43
Interest expense	(298)	(147)	(7)
Finance result, net	(1,401)	(3,872)	3,360
Loss before tax	(50,951)	(26,411)	(7,096)
Income tax expense	0	0	0
Loss for the period	SFr (50,951)	SFr (26,411)	SFr (7,096)
Loss per share (EPS):
Basic and diluted, income / (loss) for the period attributable to equity holders (in CHF per share)	SFr (0.82)	SFr (0.46)	SFr (0.14)

Statements of Comprehensive Loss - CHF (SFr) SFr in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statements of Comprehensive Loss [Abstract]
Net loss for the period	SFr (50,951)	SFr (26,411)	SFr (7,096)
Other comprehensive loss not to be reclassified to income or loss in subsequent periods (net of tax)
Re-measurement losses on defined benefit plans (net of tax of CHF 0 for all periods)	(302)	(780)	(761)
Total comprehensive loss, net of tax	SFr (51,253)	SFr (27,191)	SFr (7,857)

- Definition

The total of income less expenses from continuing and discontinued operations, excluding the components of other comprehensive income. [Refer: Other comprehensive income]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 7
-IssueDate 2018-01-01
-Paragraph 18
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=7&date=2018-03-01&anchor=para_18_b&doctype=Standard
-URIDate 2018-03-16

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 1
-IssueDate 2018-01-01
-Paragraph 24
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=1&date=2018-03-01&anchor=para_24_b&doctype=Standard
-URIDate 2018-03-16

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 1
-IssueDate 2018-01-01
-Paragraph 32
-Subparagraph a
-Clause ii
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=1&date=2018-03-01&anchor=para_32_a_ii&doctype=Standard
-URIDate 2018-03-16

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2018-01-01
-Paragraph 28
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=8&date=2018-03-01&anchor=para_28_b&doctype=Standard
-URIDate 2018-03-16

Reference 5: http://www.xbrl.org/2003/role/exampleRef
-Note Effective on first application of IFRS 9
-Name IFRS
-Number 4
-IssueDate 2018-01-01
-Paragraph 39L
-Subparagraph e
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=4&date=2018-03-02&anchor=para_39L_e&doctype=Standard&book=b
-URIDate 2018-03-16

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2018-01-01
-Paragraph 23
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=8&date=2018-03-01&anchor=para_23&doctype=Standard
-URIDate 2018-03-16

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Name IFRS
-Number 12
-IssueDate 2018-01-01
-Paragraph B10
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=12&date=2018-03-01&anchor=para_B10_b&doctype=Appendix&seq=2
-URIDate 2018-03-16

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2018-01-01
-Paragraph 106
-Subparagraph d
-Clause i
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2018-03-01&anchor=para_106_d_i&doctype=Standard
-URIDate 2018-03-16

Reference 9: http://www.xbrl.org/2003/role/exampleRef
-Note Effective 2021-01-01
-Name IFRS
-Number 17
-IssueDate 2018-01-01
-Paragraph 113
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=17&date=2018-03-01&anchor=para_113_b&doctype=Standard
-URIDate 2018-03-16

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2018-01-01
-Paragraph 81A
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2018-03-01&anchor=para_81A_a&doctype=Standard
-URIDate 2018-03-16

+ Details

Statements of Comprehensive Loss (Parenthetical) - CHF (SFr) SFr in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Other comprehensive loss not to be reclassified to income or loss in subsequent periods (net of tax)
Income tax expense	SFr 0	SFr 0	SFr 0

Statements of Changes in Equity - CHF (SFr) SFr in Thousands	Total	Share Capital [Member]	Share Premium [Member]	Accumulated Losses [Member]
Balance, beginning of period at Dec. 31, 2015	SFr 71,043	SFr 928	SFr 110,496	SFr (40,381)
Net loss for the period	(7,096)	0	0	(7,096)
Other comprehensive loss	(761)	0	0	(761)
Total comprehensive loss, net of tax	(7,857)	0	0	(7,857)
Share-based payments	1,317	0	0	1,317
Preferred Series E extension shares	13,205	28	13,177	0
Proceeds from IPO net of underwriting fees	69,388	138	69,250	0
Issuance of shares:
Exercise of options	301	41	260	0
Transaction costs	(5,017)	0	(5,017)	0
Balance, end of period at Dec. 31, 2016	142,380	1,135	188,166	(46,921)
Net loss for the period	(26,411)	0	0	(26,411)
Other comprehensive loss	(780)	0	0	(780)
Total comprehensive loss, net of tax	(27,191)	0	0	(27,191)
Share-based payments	1,579	0	0	1,579
Proceeds from IPO net of underwriting fees	0
Issuance of shares:
Restricted Share Awards	0	0	74	(74)
Exercise of options	71	12	59	0
Balance, end of period at Dec. 31, 2017	116,839	1,147	188,299	(72,607)
Net loss for the period	(50,951)	0	0	(50,951)
Other comprehensive loss	(302)	0	0	(302)
Total comprehensive loss, net of tax	(51,253)	0	0	(51,253)
Share-based payments	2,518	0	0	2,518
Proceeds from IPO net of underwriting fees	111,529	200	111,329	0
Issuance of shares:
Restricted Share Awards	1	1	535	(535)
Exercise of options	4	3	1	0
Transaction costs	(2,015)	0	(2,015)	0
Balance, end of period at Dec. 31, 2018	SFr 177,623	SFr 1,351	SFr 298,149	SFr (121,877)

Statements of Cash Flows - CHF (SFr) SFr in Thousands	12 Months Ended
Statements of Cash Flows - CHF (SFr) SFr in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating activities
Net loss for the period	SFr (50,951)	SFr (26,411)	SFr (7,096)
Adjustments to reconcile net income for the period to net cash flows:
Depreciation of property, plant and equipment	961	580	278
Finance result, net	1,401	3,872	(3,360)
Share-based compensation expense	2,518	1,579	1,317
Changes in net employee defined benefit liability	437	348	250
Accrued interest	50	99	0
Changes in working capital:
Increase in prepaid expenses	(924)	(162)	(494)
Increase in accrued income	(868)	(1,910)	(842)
Decrease/(increase) in other current receivables	698	(401)	(248)
Increase in accrued expenses	2,113	2,940	1,564
Decrease/(increase) in deferred income	(18)	(156)	476
Increase/(decrease) in long-term debt obligation	(53)	204	0
Increase/(decrease) in trade and other payables	864	(2,853)	2,592
Cash used in operating activities	(43,772)	(22,271)	(5,563)
Interest income	29	330	43
Finance costs	(335)	(153)	(126)
Net cash flows used in operating activities	(44,078)	(22,094)	(5,646)
Investing activities
Short-term financial assets	(30,000)	0	0
Purchases of property, plant and equipment	(1,858)	(1,802)	(899)
Rental deposits	(178)	(40)	0
Net cash flows used in investing activities	(32,036)	(1,842)	(899)
Financing activities
Proceeds from issuance of preferred Series E	0	0	13,206
Proceeds from public offerings of common shares, net of underwriting fees	111,529	0	69,388
Transaction costs on public offerings of common shares	(2,015)	0	(4,105)
Proceeds from issuance of common shares	5	71	301
Proceeds from long-term debt obligation	198	200	0
Repayment of short-term debt obligation	(339)	0	0
Net cash flows provided by financing activities	109,378	271	78,790
Net increase/(decrease) in cash and cash equivalents	33,264	(23,665)	72,245
Cash and cash equivalents, beginning of period	124,377	152,210	76,522
Exchange gains on cash and cash equivalents	(1,179)	(4,168)	3,443
Cash and cash equivalents, end of period	156,462	124,377	152,210
Net increase/(decrease) in cash and cash equivalents	SFr 33,264	SFr (23,665)	SFr 72,245

Statements of Cash Flows (Parenthetical) SFr in Millions	12 Months Ended
Statements of Cash Flows (Parenthetical) SFr in Millions	Dec. 31, 2018 CHF (SFr)
Supplementary non-cash activity include the following [Abstract]
Long-term debt reclassified to short-term debt	SFr 0.7
Finance receivables recorded to long-term obligations	0.2
Write off of fixed assets	0.0
Top of Range [Member]
Supplementary non-cash activity include the following [Abstract]
Non-cash purchase, property plant and equipment	SFr 0.1

General information

12 Months Ended

Dec. 31, 2018

General information [Abstract]

General information

AC Immune SA (the “Company,” or “AC Immune,” “ACI,” “we,” “our,” “ours,” “us”) is a clinical stage biopharmaceutical company leveraging our two proprietary technology platforms to discover, design and develop novel, proprietary medicines for prevention, diagnosis and treatment of neurodegenerative diseases associated with protein misfolding. Misfolded proteins are generally recognized as the leading cause of neurodegenerative diseases, such as Alzheimer’s disease, or AD, and Parkinson’s disease, or PD, with common mechanisms and drug targets, such as Abeta, Tau and alpha-synuclein. Our corporate strategy is founded upon a three-pillar approach that targets Alzheimer’s disease, non-Alzheimer’s neurodegenerative diseases including neuro-orphan indications and diagnostics. We use our two unique proprietary platform technologies, SupraAntigen (conformation-specific biologics) and Morphomer (conformation-specific small molecules), to discover, design and develop medicines and diagnostics to target misfolded proteins.

The Company was initially incorporated as a limited liability company on February 13, 2003 in Basel and effective August 25, 2003 was transitioned into a stock company. The Company’s corporate headquarters are located at EPFL Innovation Park Building B, 1015 Lausanne, Switzerland.

Basis of preparation

12 Months Ended

Dec. 31, 2018

Basis of preparation [Abstract]

Basis of preparation

Going concern

The financial statements have been prepared on the basis that the Company will continue as a going concern after considering the Company’s cash position of CHF 156.5 million and short-term financial assets of CHF 30.0 million as of December 31, 2018. This total derives from multiple capital raising efforts and revenues from collaboration agreements. In Q3 2018, the Company completed three offerings, raising USD 117.5 (CHF 116.3) million in gross proceeds before underwriting discounts and expenses.

To date, the Company has financed its cash requirements primarily from its public offerings, share issuances and revenues from collaboration agreements. The Company is a clinical stage company and is exposed to all the risks inherent to establishing a business. Inherent to the Company’s business are various risks and uncertainties, including the substantial uncertainty as to whether current projects will succeed. The Company’s success may depend in part upon its ability to (i) establish and maintain a strong patent position and protection, (ii) enter into collaborations with partners in the biotech and pharmaceutical industry, (iii) successfully move its product candidates through clinical development, (iv) attract and retain key personnel, and (v) acquire capital to support its operations.

Statement of compliance

The financial statements have been prepared in accordance with International Financial Reporting Standards (“IFRS”) as issued by the International Accounting Standards Board (“IASB”). These financial statements have been approved for issue by the Board of Directors on March 19, 2019.

Basis of measurement

The financial statements have been prepared under the historical cost convention except for items that are required to be accounted for at fair value.

Functional currency

The financial statements of the Company are presented in Swiss Francs (CHF), which is also the functional currency of the Company. All financial information presented in Swiss Francs (except for share capital and earnings per share data) has been rounded to the nearest thousand CHF (CHF thousands), unless otherwise indicated.

Summary of significant accounting policies

12 Months Ended

Dec. 31, 2018

Summary of significant accounting policies [Abstract]

Summary of significant accounting policies

The principal accounting policies adopted in the preparation of these financial statements are set out below. These policies have been consistently applied to all the years presented, unless otherwise stated.

Current vs. non-current classification

The Company presents assets and liabilities in the balance sheet based on current/non-current classification. The Company classifies all amounts to be realized or settled within 12 months after the reporting period to be current and all other amounts to be non-current.

Foreign currency transactions

Foreign currency transactions are translated into the functional currency Swiss Francs (CHF) using prevailing exchange rates at the dates of the transactions. Monetary assets and liabilities denominated in foreign currencies are translated into CHF at rates of exchange prevailing at reporting date. Any gains or losses from these translations are included in the statements of loss in the period in which they arise.

Revenue recognition

Effective January 1, 2018, the Company adopted IFRS 15 Revenue from Contracts with Customers, without though deeming any adjustments necessary in the transition to the new standard. This standard applies to all contracts with customers, except for contracts that are within the scope of other standards, such as leases, insurance, collaboration arrangements and financial instruments. Under IFRS 15, an entity recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that an entity determines are within the scope of IFRS 15, the entity performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that the entity will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, once the contract is determined to be within the scope of IFRS 15, the Company assesses the goods or services promised within each contract and determines those that are performance obligations, and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. For a complete discussion of accounting for contract revenue, see Note 11, “Revenues.”

License of intellectual property

If the license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenues from non-refundable, up-front fees allocated to the license when the license is transferred to the customer and the customer is able to use and benefit from the license. For licenses that are sold in conjunction with a related service, the Company uses judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time. If the performance obligation is settled over time, the Company determines the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, up-front fees. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition.

Milestone payments

At the inception of each arrangement that includes development, regulatory and/or commercial milestone payments, the Company evaluates whether the milestones are considered highly probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. If it is highly probable that a significant revenue reversal would not occur in future periods, the associated milestone value is included in the transaction price. These amounts for the performance obligations under the contract are recognized as they are satisfied. At the end of each subsequent reporting period, the Company re-evaluates the probability of achievement of such milestones and any related constraint, and if necessary, adjusts its estimate of the overall transaction price. Any such adjustments recorded would affect contract revenues and earnings in the period of adjustment.

Research and Development Services

The Company has certain arrangements with our collaboration partners that include contracting our full-time employees for research and development programs. The Company assesses if these services are considered distinct in the context of each contract and, if so, they are accounted for as separate performance obligations. These revenues are recorded in contract revenue as the services are performed.

Contract Balances

The Company receives payments and determines credit terms from its customers for its various performance obligations based on billing schedules established in each contract. The timing of revenue recognition, billings and cash collections results in billed other current receivables, accrued income (contract assets), and deferred income (contract liabilities) on the balance sheets. Amounts are recorded as other current receivables when the Company’s right to consideration is unconditional. The Company does not assess whether a contract has a significant financing component if the expectation at contract inception is such that the period between payment by the licensees and the transfer of the promised goods or services to the licensees will be one year or less.

Research and development expenditure

Given the stage of development of the Company’s products, all research expenditure is recognized as expense when incurred. Research and development expenditures include:

●

the cost of acquiring, developing and manufacturing active pharmaceutical ingredients for product candidates that have not received regulatory approval, clinical trial materials and other research and development materials;

●

fees and expenses incurred under agreements with contract research organizations, investigative sites, and other entities in connection with the conduct of clinical trials and preclinical studies and related services, such as administrative, data management, and laboratory services;

●

fees and costs related to regulatory filings and activities;

●

costs associated with pre-clinical and clinical activities; and

●

employee-related expenses, including salaries and bonuses, benefits, travel and stock-based compensation expense

For external research contracts, expenses include those associated with contract research organizations, or CROs. The invoicing from CROs for services rendered do not always align with work performed. We accrue the cost of services rendered in connection with CRO activities based on our estimate of the “stage of completion” for such contracted services. We maintain regular communication with our CRO vendors to gauge the reasonableness of our estimates and accrue expenses as of the balance sheet date in the financial statement based on facts and circumstances known at the time.

Registration costs for patents are part of the expenditure for research and development projects. Therefore, registration costs for patents are expensed when incurred as long as the research and development project concerned does not meet the criteria for capitalization.

Property, plant and equipment

Equipment is shown at historical acquisition cost, less accumulated depreciation and any accumulated impairment losses. Historical costs include expenditures that are directly attributable to the acquisition of the property, plant and equipment. Depreciation is calculated using a straight-line method to write off the cost of each asset to its residual value over its estimated useful life as follows:

IT equipment	3 years
Laboratory equipment	5 years
Leasehold improvements / furniture	5 years

The assets’ residual values and useful lives are reviewed, and adjusted if appropriate, at each balance sheet date. Where an asset’s carrying amount is greater than its estimated recoverable amount, it is written down to its recoverable amount.

Gains and losses on disposals are determined by comparing the disposal proceeds with the carrying amount and are included in the statements of loss.

Fair value of financial assets and liabilities

The Company’s financial assets and liabilities are comprised of receivables, cash and cash equivalents, trade payables and debt obligations. The fair value of these financial instruments approximate their respective carrying values due to the short term maturity of these instruments and are held at their amortized cost in accordance with IFRS 9.

Receivables

Receivables are non-derivative financial assets with fixed payments that are not quoted in an active market. They arise when the Company provides money, goods or services directly to a debtor with no intention of trading the receivable. They are included in current assets, except for those with maturities greater than 12 months after the balance sheet date, which are classified as long-term assets. Receivables are recognized at their billing value. An allowance for doubtful accounts is recorded for potential estimated losses when there is evidence of the debtor’s inability to make required payments and the Company assesses on a forward looking basis the expected credit losses associated with these receivables held at amortized cost.

Short-term financial assets

Short-term financial assets are held with external financial institutions and comprise fixed-term deposits with maturities ranging from more than 3 until 12 months in duration.

Cash and cash equivalents

Cash and cash equivalents include deposits held with external financial institutions and cash on hand. All cash and cash equivalents are either in cash or in deposits with original duration of less than 3 months.

The Company assesses at each period whether there is objective evidence that financial assets are impaired.

Trade payables

Trade payables are amounts due to third parties in the ordinary course of business.

Debt obligations

The Company’s debt obligations relate to its agreement with a third party and are measured as of the period end date based on the repayment terms when originated.

Share capital and public offerings

Ordinary (Common) Shares are classified as equity, as were all Preferred Shares previously outstanding prior to the IPO. Expenses directly attributable to the issuance of new shares are shown in equity as a deduction, net of tax, from the proceeds. See Note 8, “Share Capital.”

Employee benefits

Post-employment benefits

The Company operates the mandatory pension schemes for its employees in Switzerland. The schemes are generally funded through payments to insurance companies. The Company has a pension plan designed to pay pensions based on accumulated contributions on individual savings accounts. However, this plan is classified as a defined benefit plan under IAS 19.

The net defined benefit liability is the present value of the defined benefit obligation at the balance sheet date minus the fair value of plan assets. Significant estimates are used in determining the assumptions incorporated in the calculation of the pension obligations, which is supported by input from independent actuaries. The defined benefit obligation is calculated annually with the assistance of an independent actuary using the projected unit credit method, which reflects services rendered by employees to the date of valuation, incorporates assumptions concerning employees’ projected salaries, pension increases as well as discount rates of highly liquid corporate bonds which have terms to maturity approximating the terms of the related liability.

Remeasurements of the net defined benefit liability, which comprise actuarial gains and losses, the return on plan assets (excluding interest), are recognized immediately in Other Comprehensive Loss. Past service costs, including curtailment gains or losses, are recognized immediately as a split in research and development and general and administrative expenses within the operating results. Settlement gains or losses are recognized in either research and development and/or general and administrative expenses within the operating results. The Company determines the net interest expense (income) on the net defined benefit liability for the period by applying the discount rate used to measure the defined benefit obligation at the beginning of the annual period or in case of any significant events between measurement dates to the then-net defined benefit liability, taking into account any changes in the net defined benefit liability during the period as a result of contributions and benefit payments. Net interest expense and other expenses related to defined benefit plans are recognized in the statement of income.

Share-based compensation

The Company operates an equity-settled, share-based compensation plan. The fair value of the employee services received in exchange for the grant of equity based awards is recognized as an expense. The total amount to be expensed over the vesting period is determined by reference to the fair value of the instruments granted, excluding the impact of any non-market vesting conditions. Non-market vesting conditions are included in assumptions about the number of instruments that are expected to become exercisable. At each balance sheet date, the Company revises its estimates of the number of instruments that are expected to become exercisable. It recognizes the impact of the revision of original estimates, if any, prospectively in the income statement, and a corresponding adjustment to equity over the remaining vesting period.

Stock options granted under the Company’s stock option plans A, B, C and the 2016 Stock Option and Incentive Plan are valued using the Black-Scholes option pricing model (see Note 16). This valuation model as well as parameters used such as expected volatility and expected term of the stock options are partially based on management’s estimates.

The proceeds received net of any directly attributable transaction costs are credited to share capital (nominal value) and share premium when the options are exercised.

We estimate the fair value of non-vested stock awards (restricted shares and restricted share units) using a reasonable estimate of market value of the common stock on the date of the award. We classify our share-based payments as equity-classified awards as they are settled in shares of our common stock. We measure equity-classified awards at their grant date fair value and do not subsequently remeasure them. Compensation costs related to equity-classified awards are equal to the fair value of the award at grant-date amortized over the vesting period of the award using the graded method. We reclassify that portion of vested awards to share premium as the awards vest.

Provisions

Provisions are recognized when the Company has a present legal or constructive obligation as a result of past events where it is more likely than not that an outflow of resources will be required to settle the obligation, and a reliable estimate of the amount can be made.

Taxation

Current income tax assets and liabilities for the period are measured at the amount expected to be recovered from or paid to the taxation authorities. The tax rates and tax laws used to compute the tax amounts are those that are enacted or substantively enacted, at the reporting date in accordance with the fiscal regulations of the respective country where the Company operates and generates taxable income. Deferred tax is provided using the liability method on temporary differences between the tax bases of assets and liabilities and their carrying amounts for financial reporting purposes at the reporting date.

Deferred tax assets and liabilities are measured at the tax rates that are expected to apply in the year when the asset is realized or the liability is settled, based on tax rates (and tax laws) that have been enacted or substantively enacted at the reporting date. If required, deferred taxation is provided in full using the liability method, on all temporary differences at the reporting dates. It is calculated at the tax rates that are expected to apply to the period when it is anticipated the liabilities will be settled, and it is based on tax rates (and laws) that have been enacted or substantively enacted at the reporting date.

Deferred income tax assets are recognized to the extent that it is probable that future taxable profit will be available against which the temporary differences can be utilized. Deferred tax assets are reviewed at each reporting date and are reduced to the extent that it is no longer probable that the related tax benefit will be realized. Although the Company has substantial tax loss carryforwards, historically, due to the fact that the Company had limited certainty on the achievement of key milestones, it has not recognized any deferred tax assets as the probability for use is low.

Earnings per share

The Company presents basic earnings per share for each period in the financial statements. The earnings per share is calculated by dividing the earnings of the period by the weighted average number of shares (common and preferred) outstanding during the period. Diluted earnings per share reflect the potential dilution that could occur if dilutive securities such as share options were vested or exercised into common shares or resulted in the issuance of common shares that would participate in net income. Anti-dilutive shares are excluded from basic and dilutive earnings per share calculation.

Preferred shares

Judgment was required in determining the classification of the Preferred Shares issued by the Company as either equity or liabilities. The Preferred shareholders received certain preference rights that represented a significant proportion of the net assets of the Company in the case of liquidation or certain exit events, the occurrence of which was outside the control of the Company. These Preferred Shares remained outstanding until the Company completed an IPO in September 2016 and at that time the Preferred Shares were converted from Preferred Shares to Common Shares on a one-for-one basis.

Critical judgments and accounting estimates

The preparation of financial statements in conformity with IFRS requires management to make judgments, estimates and assumptions that affect the application of accounting policies and the reported amounts of assets, liabilities, income and expenses.

The areas where AC Immune has had to make judgments, estimates and assumptions relate to (i) revenue recognition on collaboration and licensing agreements, (ii) clinical development accruals, (iii) net employee defined benefit liability, (iv) income taxes and (v) share-based compensation. Actual results may differ from these estimates. Estimates and underlying assumptions are reviewed on an ongoing basis. Revisions to accounting estimates are recognized in the period in which the estimates are revised and in any future periods affected.

Income taxes

As disclosed in Note 14, the Company has tax losses that can generally be carried forward for a period of 7 years from the period the loss was incurred. These tax losses represent potential value to the Company to the extent that the Company is able to create taxable profits before the expiry period of these tax losses. The Company has not recorded any deferred tax assets in relation to these tax losses.

Segment reporting

The Company has one segment. The Company currently focuses all of its resources on discovering and developing therapeutic and diagnostic products targeting misfolded proteins.

The Company is managed and operated as one business. A single management team that reports to the chief operating decision maker comprehensively manages the entire business. Accordingly, the Company views its business and manages its operations as one reportable segment. Non-current assets are located in and revenue is attributable to the Company’s country of domicile, Switzerland.

Accounting pronouncements – not yet adopted

The following pronouncements from the IASB will become effective for future financial reporting periods and have not yet been adopted by AC Immune.

IFRS 16 Leases provides a new model for lessee accounting in which all leases, other than short-term and low-value leases, will be accounted for by the recognition on the balance sheet of a right-of-use asset and a lease liability, and the subsequent amortization of the right-of-use asset over the lease term. IFRS 16 will be effective for annual periods beginning on or after January 1, 2019 with early adoption permitted. AC Immune has completed its assessment of the impact of this standard on its financial statements and we estimate an increase of approximately CHF 2.2 million for the right-of-use assets and lease liabilities associated with our operating leases upon adoption. The Company will adopt this standard as of the effective date using the Modified Retrospective approach with there being no cumulative effect adjustment to the opening balance of accumulated losses. We believe the adoption of this standard will not have a significant impact on our statements of loss and comprehensive loss, changes in equity, and cash flows.

There are no other standards that are not yet effective and that would be expected to have a material impact on the entity in the current or future reporting periods and on foreseeable future transactions.

Accounting pronouncements – recently adopted

IFRS 15 Revenue from Contracts with Customers

In May 2014, the International Accounting Standards Board (IASB) issued IFRS 15 – Revenue from Contracts with Customers which amends the guidance for accounting for revenues from contracts with customers. This IFRS replaces all current revenue standards in IFRS including IAS 11 – Construction Contracts, IAS 18 – Revenue and various interpretations. The Company adopted this new standard on January 1, 2018, and would have recognized the cumulative effect of initially applying the new revenue standard as an adjustment to the opening balance of accumulated losses; however, the Company did not deem any adjustments required in the transition to the new standard. The comparative information has not been restated and continues to be reported under the accounting standards in effect for those periods.

IFRS 9 Financial Instruments

IFRS 9 Financial Instruments supersedes IAS 39 Financial Instruments: Recognition and Measurement and was adopted by the Company on January 1, 2018. IFRS 9 covers classification and measurement of financial assets and financial liabilities, impairment of financial assets and hedge accounting. The Company noted no impact to its financial statements upon adoption of this standard.

Property, plant and equipment

12 Months Ended

Dec. 31, 2018

Property, plant and equipment [Abstract]

Property, plant and equipment

in CHF thousands	Furniture			Computers /IT			Lab Equipment			Leasehold Improvements			Total
Acquisition Cost:
Balance at December 31, 2017		85			569			4,161			272			5,087
Acquisitions		41			456			1,357			78			1,932
Disposals		—			—			(151	)		—			(151	)
Balance at December 31, 2018		126			1,025			5,367			350			6,868

Accumulated depreciation:
Balance at December 31, 2017		(59	)		(259	)		(2,311	)		(105	)		(2,734	)
Depreciation expense		(18	)		(196	)		(697	)		(50	)		(961	)
Disposals		—			—			151			—			151
Balance at December 31, 2018		(77	)		(455	)		(2,857	)		(155	)		(3,544	)

Carrying Amount:
December 31, 2017		26			310			1,850			167			2,353
December 31, 2018		49			570			2,510			195			3,324

in CHF thousands	Furniture			Computers /IT			Lab Equipment			Leasehold Improvements			Total
Acquisition Cost:
Balance at December 31, 2016		81			298			2,792			103			3,274
Acquisitions		4			271			1,369			169			1,813
Balance at December 31, 2017		85			569			4,161			272			5,087

Accumulated depreciation:
Balance at December 31, 2016		(45	)		(172	)		(1,858	)		(79	)		(2,154	)
Depreciation expense		(14	)		(87	)		(453	)		(26	)		(580	)
Balance at December 31, 2017		(59	)		(259	)		(2,311	)		(105	)		(2,734	)

Carrying Amount:
December 31, 2016		36			126			934			24			1,120
December 31, 2017		26			310			1,850			167			2,353

For the years ended December 31, 2018, 2017 and 2016, the Company incurred CHF 1.0 million, 0.6 million and CHF 0.3 million in depreciation expense, respectively.

Cash and cash equivalents and financial assets

12 Months Ended

Dec. 31, 2018

Cash and cash equivalents and financial assets [Abstract]

Cash and cash equivalents and financial assets

5.	Cash and cash equivalents and financial assets

The following tables summarize the Company’s cash and cash equivalents and short-term financial assets as of December 31, 2018 and 2017:

	As of December 31,
in CHF thousands	2018		2017
Cash and cash equivalents		156,462		124,377
Total		156,462		124,377

	As of December 31,
in CHF thousands	2018		2017
Short-term financial assets due in one year or less		30,000		—
Total		30,000		—

The Company’s cash and cash equivalents are maintained in the following respective currencies as of December 31, 2018 and 2017:

	As of December 31,
in CHF thousands	2018		2017
Cash and cash equivalents		156,462		124,377
Total		156,462		124,377

By currency
CHF		126,218		103,272
EUR		11,471		3,658
USD		18,773		17,447
Total cash and cash equivalents		156,462		124,377

At the balance sheet dates, Company funds were held in CHF, EUR and USD currencies. As of December 31, 2018 and 2017, funds in EUR and USD were translated into CHF at a rate of 1.125 and 0.983 and 1.169 and 0.976, respectively for each currency and year.

The Company also has two deposits in escrow accounts totaling CHF 0.3 million and 0.1 million for the lease of the Company’s premises as of December 31, 2018 and 2017, respectively.

Prepaid expenses and accrued income

12 Months Ended

Dec. 31, 2018

Prepaid expenses and accrued income [Abstract]

Prepaid expenses and accrued income

	As of December 31,
in CHF thousands	2018		2017
Prepaid expenses		2,364		1,440
Accrued income		3,667		2,799
Total		6,031		4,239

The prepaid expenses relate mainly to research contracts with down-payments at contract signature and the related activities will start or continue into 2019.

Accrued income consists of CHF 1.2 million as of December 31, 2018 associated with our Biogen collaboration and CHF 2.1 million associated with our Janssen collaboration (see Note 11). This amount represents 33.5% and 56.8%, respectively of our total accrued income as of December 31, 2018.

Other current receivables

12 Months Ended

Dec. 31, 2018

Other current receivables [Abstract]

Other current receivables

	As of December 31,
in CHF thousands	2018		2017
Other receivables		17		691
Swiss VAT		209		112
Withholding tax		10		115
Total		236		918

The maturity of these assets is less than three months. The Company considers the counterparty risk as low and the carrying amount of these receivables is considered to approximate their fair value.

Share capital

12 Months Ended

Dec. 31, 2018

Share capital [Abstract]

Share capital

As of December 31, 2018 and 2017, the issued share capital amounted to CHF 1,351,364 and CHF 1,147,104 respectively and comprised of Common Shares of 67,562,333 and 57,355,188, respectively.

The table below summarizes the Company’s capital structure:

	Common Shares		in CHF thousands
	Number		Share Capital		Share Premium
December 31, 2016		56,773,392		1,135		188,166
Issuance of Shares – Incentive Plans		581,796		12		133

December 31, 2017		57,355,188		1,147		188,299
Issuance of Shares – Incentive Plans		207,145		4		537
Issuance of Shares – Public Offering (net of transaction costs)		10,000,000		200		109,313
December 31, 2018		67,562,333		1,351		298,149

The Common Shares nominal values of CHF 0.02 per share are fully paid in.

Preferred Shares

AC Immune had five classes (Class A, B, C, D and E) of Preferred Shares outstanding as of December 31, 2015. These Preferred Shares remained outstanding until the Company completed an IPO in September 2016 and at that time the Preferred Shares were converted to Common Shares on a one-for-one basis. The Preferred Shares were a class of shares that AC Immune SA issued in connection with five separate capital increases and conveyed voting rights and certain other rights to their holders.

The holders of Preferred Shares owned 80.1% of the total amount of shares outstanding (assuming conversion of the Preferred Shares into Common Shares on a one-for-one basis) as of December 31, 2015 and the Company’s Board of Directors were predominantly the holders of Preferred Shares. The Preferred Shares had been the primary source of equity financing for the Company for more than 13 years until the Company completed an IPO in September 2016, at which point all Preferred Shares were converted to Common Shares. The Preferred Shares did not have mandatory redemption features; however, the Shareholders’ Agreement provided for conversion of Preferred Shares into Common Shares as a result of an IPO. The redemption of the Preferred Shares was authorized by the Company’s Board of Directors.

The voting rights associated with Preferred Shares were the same as for Common Shares. Each Preferred Share entitled the holder to one vote. No dividends were paid on the Preferred Shares and the holders of Preferred Shares were not entitled to any dividends unless dividends are paid on the Common Shares.

The Preferred Shares had a liquidation preference wherein, in the event of a change of control or a liquidation of the Company, the holders of Preferred Shares were entitled to receive, prior and in preference to the holders of Common Shares, the amount corresponding to the price paid for each Preferred Share. Thereafter, all holders of Preferred Shares participated with the holders of Common Shares on an as-if-converted basis in any remaining proceeds.

On April 15, 2016, AC Immune completed a private placement of Series E preferred shares, each with a nominal value of CHF 0.02 per share (the “Series E Private Placement Extension”). An aggregate 1,401,792 Series E preferred shares were issued at a price of USD 9.64 (CHF 9.42) per preferred share to certain strategic investors, individuals and existing shareholder in the Series E Private Placement Extension for an aggregate subscription amount of approximately USD 13.5 (CHF 13.2) million. The Series E preferred shares had substantially the same terms as the Series A, B, C and D preferred shares and were accounted for as equity on AC Immune’s balance sheet and subsequently converted to Common Shares as a result of the IPO.

Initial Public Offering (IPO)

On September 22, 2016, AC Immune successfully priced a 6.0 million common share IPO at USD 11.00 per share. On the same day, the underwriters exercised the overallotment option which resulted in a further 900,000 common shares being placed in the market and took the total number of shares offered to investors to 6.9 million common shares. The gross proceeds received were USD 75.9 (CHF 74.5) million while the proceeds net of underwriting fees amounted to USD 70.6 (CHF 69.3) million.

The IPO resulted in an increase of CHF 64.2 million in the share premium of AC Immune excluding the effect of transaction costs associated with the IPO related to the issuance of new shares. Transaction costs associated with the IPO and related to the issuance of new shares were charged directly against the share premium account thereby reducing the total equity reported.

Follow-On Offerings

On July 24, 2018, the Company announced that it had closed the first subscription rights offering and underwritten primary offering of its common shares, and that the underwriters had exercised in full their option to purchase an additional 1,108,695 shares at a price per share of USD 11.75. The underwriters’ exercise of the option to purchase additional shares brought the total number of common shares sold by the Company to 8,500,000 shares, resulting in total gross proceeds raised in these offerings, before underwriting discounts and estimated expenses of the offering, to approximately USD 99.9 (CHF 98.9) million. On July 20, 2018, the Company commenced a second subscription rights offering of up to 1,500,000 shares. At closing of the second subscription rights offering on July 31, 2018, the Company issued 1,500,000 additional common shares, resulting in gross proceeds of approximately USD 17.6 (CHF 17.4) million.

At the conclusion of these three offerings, the Company raised gross proceeds of USD 117.5 (CHF 116.3) million. Net underwriting fees and transaction costs totaled CHF 6.8 million for a net total of CHF 109.5 million. Transaction costs associated with these offerings and related to the issuance of new shares were charged directly against the share premium account thereby reducing the total equity reported.

Shelf Registration Statement

On May 4, 2018, the Company filed a shelf registration statement on Form F-3 (Reg. No. 333-2246694) (the “Shelf Registration Statement”) with the SEC. The Shelf Registration Statement was declared effective by the SEC on June 8, 2018.

The Shelf Registration Statement allows the Company to offer and sell, from time to time, up to USD 350,000,000 of common stock, debt securities, warrants, purchase contracts, units, subscription rights or any combination of the foregoing in one or more future public offerings. The terms of any future offering would be determined at the time of the offering and would be subject to market conditions and approval by the Company’s Board of Directors. Any offering of securities covered by the Shelf Registration Statement will be made only by means of a written prospectus and prospectus supplement authorized and filed by the Company.

Since the Company raised USD 117,500,000 in its three offerings completed in July 2018, the Company may execute one or more future offering of securities covered by the Shelf Registration Statement up to USD 232,500,000.

Trade payables, accrued liabilities and deferred income

12 Months Ended

Dec. 31, 2018

Trade payables, accrued liabilities and deferred income [Abstract]

Trade payables and accrued liabilities

Trade payables, accrued liabilities and deferred income

	As of December 31,
in CHF thousands	2018		2017
Trade and other payables		1,979		1,092
Accrued research and development costs		6,803		5,430
Accrued payroll expenses		2,482		2,420
Other accrued expenses		1,135		457
Deferred income		351		355
Total		12,750		9,754

An accrual of CHF 1.8 million and CHF 1.1 million was recognized for performance-related remuneration within Accrued payroll expenses for 2018 and 2017, respectively.

For the year ended December 31, 2018 and 2017, the Company has recorded CHF 0.4 million in deferred income in relation to research funding commitments from Biogen.

Debt obligation

12 Months Ended

Dec. 31, 2018

Debt obligation [Abstract]

Debt obligation

10.

Debt obligation

On January 4, 2016, September 13, 2016 and January 26, 2018 for fiscal years 2016, 2017 and 2018, respectively, AC Immune obtained separate funding commitment notices from the LuMind Research Down Syndrome Foundation (“LuMind”) totaling USD 200 thousand in each instance. Per the Research Grant Agreement, AC Immune has an obligation to reimburse LuMind for an amount equal to 125% of the then funding commitment made by LuMind to AC Immune.

On October 31, 2018, LuMind and the Company modified the repayment terms in an effort to fund a Down Syndrome Clinical Trials Network. The repayment terms were modified such that the Company will repay the outstanding balance in three installments in 2018, 2019 and 2020, with the total repayment to equal the total the Company is to receive in funding with the additional 25% interest.

The Company accounted for this modification as an extinguishment within IFRS 9 and recorded a CHF 0.1 million extinguishment gain with Finance result, net in the statements of loss. The Company reclassified a certain portion of Long-term debt obligation from non-current to current liabilities in the balance sheets to reflect the amended repayment terms. Additionally, per this modified payment term, the Company and LuMind memorialized the receipt of one final USD 200 (CHF 199) thousand payment due from LuMind in 2019. The Company has recorded this as a finance receivable and an increase to the obligation accordingly.

AC Immune has recorded in current liabilities a Short-term debt obligation for the total USD 334 (CHF 332) thousand committed. As of December 31, 2018 and 2017, the Company recorded a Long-term debt obligation for the total USD 187 (CHF 186) thousand and USD 500 (CHF 494) thousand, respectively.

Revenues

12 Months Ended

Dec. 31, 2018

Revenues [Abstract]

Revenues

11.

Revenues

The Company enters into licensing agreements which are within the scope of IFRS 15, under which it licenses certain rights to its product candidates and IP to third parties. The terms of these arrangements typically include payment to the Company of one or more of the following: non-refundable, up-front license fees; development, regulatory and/or commercial milestone payments; payments for research and clinical services the Company provides through either its full-time employees or third-party vendors; and royalties on net sales of licensed products commercialized from the Company’s IP. Each of these payments results in license, collaboration and other revenues, which are classified as contract revenue on the statements of loss, except for revenues from royalties on net sales of products commercialized from the Company’s IP, which are classified as royalty revenues.

Licenses of intellectual property: If the license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenues from non-refundable, up-front fees allocated to the license when the license is transferred to the customer and the customer is able to use and benefit from the license. For licenses that are sold in conjunction with a related service, the Company uses judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time. If the performance obligation is settled over time, the Company determines the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, up-front fees. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition.

Milestone payments: At the inception of each arrangement that includes development, regulatory and/or commercial milestone payments, the Company evaluates whether the milestones are considered highly probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. If it is highly probable that a significant revenue reversal would not occur in future periods, the associated milestone value is included in the transaction price. These amounts for the performance obligations under the contract are recognized as they are satisfied. At the end of each subsequent reporting period, the Company re-evaluates the probability of achievement of such milestones and any related constraint, and if necessary, adjusts its estimate of the overall transaction price. Any such adjustments recorded would affect contract revenues and earnings in the period of adjustment.

Research and development services: The Company has certain arrangements with our collaboration partners that include contracting our full-time employees for research and development programs. The Company assesses if these services are considered distinct in the context of each contract and, if so, they are accounted for as separate performance obligations. These revenues are recorded in contract revenue as the services are performed.

Sublicense revenues: The Company has certain arrangements with our collaboration partners that include provisions for sublicensing. The Company recognizes any sublicense revenues at the point in time it is highly probable to obtain and not subject to reversal in the future.

Royalties: For arrangements that include sales-based royalties, including milestone payments based on the level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). To date, the Company has not recognized any royalty revenue resulting from any of its licensing and collaboration agreements.

Contract balances: The Company receives payments and determines credit terms from its licensees for its various performance obligations based on billing schedules established in each contract. The timing of revenue recognition, billings and cash collections results in billed other current receivables, accrued income (contract assets), and deferred income (contract liabilities) on the Balance Sheet. Amounts are recorded as other current receivables when the Company’s right to consideration is unconditional. The Company does not assess whether a contract has a significant financing component if the expectation at contract inception is such that the period between payment by the licensees and the transfer of the promised goods or services to the licensees will be one year or less.

The following table presents changes in the Company’s contract assets and liabilities during the years ended December 31, 2018 and 2017 (in CHF thousands):

	Balance at the beginning of the reporting period		Additions		Deductions			Balance at the end of the reporting period
Twelve months ended December 31, 2018:
Accrued Income		2,799		5,846		(4,978	)		3,667
Deferred Income		355		1,533		(1,537	)		351

Twelve months ended December 31, 2017:
Accrued Income		889		3,813		(1,903	)		2,799
Deferred Income		521		1,250		(1,416	)		355

During the years ended December 31, 2018 and 2017, the Company recognized the following revenues as a result of changes in the contract asset and the contract liability balances in the respective periods (in CHF thousands):

	For the Years Ended December 31,
Revenues recognized in the period from:	2018		2017
Amounts included in the contract liability at the beginning of the period		1,551		1,401

The following tables provide contract revenue amounts by year indicated included in the Company's accompanying financial statements attributable to transactions arising from its licensing arrangements.

	For the Years Ended December 31,
in CHF thousands, by partner	2018		2017		2016
Genentech		—		14,000		14,001
Janssen		2,157		1,239		6,628
Life Molecular Imaging		—		1,080		7
Biogen		4,024		3,930		2,100
Other		1,013		6		478
Total contract revenue		7,194		20,255		23,214

Biogen and Janssen accounted for 56% and 30% of our contract revenues in 2018, respectively. Genentech and Biogen accounted for 69% and 19% of our contract revenues in 2017, respectively. Genentech and Janssen accounted for 60% and 29% of our contract revenues in 2016, respectively.

Anti-Abeta antibody in AD – 2006 agreement with Genentech

In November 2006, AC Immune signed an exclusive, worldwide licensing agreement for crenezumab, our humanized monoclonal antibody targeting misfolded Abeta. The value of this partnership is potentially greater than USD 340 (CHF 339) million.

The term of the Agreement commenced on the Effective Date and, unless sooner terminated by mutual agreement or pursuant to any other provision of the Agreement, terminates on the date on which all obligations between the Parties with respect to the payment of milestones or royalties with respect to Licensed Products have passed or expired. Either party may terminate the Agreement for any material breach by the other Party, provided a cure period of 90 days from the date notice is given.

Genentech commenced a first Phase 3 clinical study in March 2016 for crenezumab. In March 2017, Genentech started a second Phase 3 clinical trial. If crenezumab receives regulatory approval, we will be entitled to receive royalties that are tied to annual sales volumes with different royalty rates applicable in the U.S. and Europe. To date, we have received total milestone payments of USD 65 million (CHF 70.1 million) comprised of a USD 25 (CHF 31.6) million up-front payment and USD 40 (CHF 38.2) million for clinical development milestones achieved all in prior to January 1, 2017. Genentech may terminate the agreement at any time by providing three months’ notice to us. In such event all costs incurred are still refundable.

AC Immune assessed this arrangement in accordance with IFRS 15 and concluded that Genentech is a customer. The Company identified the following performance obligations under the contract: (i) a right-to-use license and (ii) conduct of research under a research plan. The Company considered the research and development capabilities of Genentech and Genentech’s right to sublicense to conclude that the license has stand-alone functionality and is distinct. The Company’s obligation to perform research does not significantly impact or modify the licenses’ granted functionality.

At execution of the agreement, the transaction price included the USD 25 (CHF 31.6) million up-front consideration received. At inception, none of the clinical or regulatory milestones had been included in the transaction price, as all milestone amounts were fully constrained. The Company has received three milestone payments since inception totaling USD 40 (CHF 38.2) million. The Company could receive greater than USD 275 (CHF 274) million or more for further regulatory milestones for this exclusive, worldwide alliance. In assessing that future regulatory milestones are fully constrained, the Company considered numerous factors, including that receipt of the milestones is outside the control of the Company and contingent upon success in future clinical trials and the licensee’s efforts. Any consideration related to royalties will be recognized when the related sales occur as they were determined to relate predominantly to the license granted to Genentech and therefore have also been excluded from the transaction price. The Company will re-evaluate the transaction price in each reporting period and as uncertain events are resolved or other changes in circumstances occur.

For the years ended December 31, 2018, 2017 and 2016, we have recognized no revenues from this arrangement.

Anti-Tau antibody in AD – 2012 agreement with Genentech

In June 2012, we entered into a second agreement with Genentech to commercialize anti-Tau antibodies for use as immunotherapeutics. The value of this exclusive, worldwide alliance is potentially greater than CHF 400 million and includes upfront and clinical, regulatory and commercial milestone payments. In addition to milestones, we will be eligible to receive royalties on sales at a percentage rate ranging from the mid-single digits to the high-single digits. The agreement also provides for collaboration on two additional indications built on the same anti-Tau antibody program as well as potential anti-Tau diagnostic products.

To date, we have received payments totaling CHF 59 million, including a CHF 14 million milestone payment received and recognized in the fourth quarter of 2017 associated with the first patient dosing in a Phase 2 clinical trial for Alzheimer’s disease with an anti-Tau monoclonal body known as RG6100, a CHF 14 million milestone payment recognized in the second quarter of 2016 and received in July 2016, associated with the announcement of the commencement of the Phase 1 clinical study of the lead anti-Tau antibody candidate and a CHF 14 million milestone payment received in 2015 in connection with the ED-GO decision. As we met all performance obligations on reaching these milestones, we have recognized revenue in the respective periods.

AC Immune assessed this arrangement in accordance with IFRS 15 and concluded that Genentech is a customer. The Company identified the following performance obligations under the contract: (i) a right-to-use license and (ii) conduct research under a research plan. The Company considered the research and development capabilities of Genentech and Genentech’s right to sublicense to conclude that the license has stand-alone functionality and is distinct. The Company’s obligation to perform research does not significantly impact or modify the licenses’ granted functionality.

At execution of the agreement, the transaction price included CHF 17 million up-front consideration received. At inception, none of the clinical or regulatory milestones had been included in the transaction price, as all milestone amounts were fully constrained. The Company has received three milestones since inception totaling CHF 42 million. The Company could also receive up to an additional CHF 368.5 million in clinical, regulatory and commercial milestones. In assessing that future clinical, regulatory or commercial milestones are fully constrained, the Company considered numerous factors, including that receipt of the milestones is outside the control of the Company and contingent upon success in future clinical trials. Any consideration related to sales-based milestones (including royalties) will be recognized when the related sales occur as they were determined to relate predominantly to the license granted to Genentech and therefore have also been excluded from the transaction price. The Company will re-evaluate the transaction price in each reporting period and as uncertain events are resolved or other changes in circumstances occur.

For the years ended December 31, 2018, 2017 and 2016, we have recognized nil, CHF 14 million and CHF 14 million from this arrangement, respectively.

Tau Vaccine in AD – 2014 agreement with Janssen Pharmaceuticals

In December 2014, we entered into an agreement with Janssen Pharmaceuticals, Inc., one of the Janssen Pharmaceutical Companies of Johnson & Johnson, to develop and commercialize therapeutic anti-Tau vaccines for the treatment of AD and potentially other Tauopathies. The value of this partnership is potentially up to CHF 500 million and includes upfront and clinical, regulatory and commercial milestones. We and Janssen will co-develop the two second generation lead therapeutic vaccines, ACI-35.030 and JACI-35.054, through Phase 1b/2a completion. From Phase 2b and onwards, Janssen will assume responsibility for the clinical development, manufacturing and commercialization of one selected second generation vaccine. ACI-35.030 and JACI-35.054 are active therapeutic vaccines stimulating the patient’s immune system to produce a polyclonal antibody response against phosphorylated Tau protein. In July 2017, AC Immune and Janssen entered into a Second Amendment to the December 2014 License, Development and Commercialization Agreement. The Amendment allows for the alignment of certain payment provisions with the new Development Plan and Research Plan activities. AC Immune and Janssen will jointly share R&D costs until the completion of the first Phase 2b.

Under the terms of the agreement, Janssen may terminate the agreement at any time after completion of the first Phase 1b clinical study by providing 90 days’ notice to us. If not otherwise terminated, the Agreement shall continue until the expiration of all royalty obligations as outlined in the contract.

The agreement also allows for the expansion to a second indication based on the same anti-Tau vaccine program and based on intellectual property related to this program.

The Company received a CHF 25.9 million up-front, non-refundable license fee which we recognized as revenue in 2014. In May 2016, we received a CHF 4.9 million payment for reaching a clinical milestone in the Phase 1b study. As we met all performance obligations on reaching the milestone, we have recognized this income as revenue.

AC Immune assessed this arrangement in accordance with IFRS 15 and concluded that Janssen is a customer. The Company identified the following performance obligations under the contract: (i) a right-to-use license and (ii) research and development services including a Development and CMC work plan. The Company considered the research and development capabilities of Janssen, Janssen’s right to sublicense, and the fact that the research and development services are not proprietary and can be provided by other vendors, to conclude that the license has stand-alone functionality and is distinct. The Company’s obligation to perform research and development services does not significantly impact or modify the licenses’ granted functionality. Based on these assessments, the Company identified the license and the research and development services as the performance obligations at the inception the arrangement, which were deemed to be distinct in the context of the contract.

At execution of the agreement, the transaction price included only the CHF 25.9 million up-front consideration received. At inception, none of the clinical, regulatory or commercial milestones has been included in the transaction price, as all milestone amounts were fully constrained. The Company did receive a CHF 4.9 million payment for reaching a clinical milestone in the first Phase 1b study in May 2016. The Company could also receive up to more than CHF 458 million in clinical, regulatory and commercial milestones as well as tiered, high-single digit to mid-double digit royalties on aggregate net sales of products. In assessing that future clinical, regulatory or commercial milestones are fully constrained, the Company considered numerous factors to determine that these milestones are not highly probable to obtain, including that receipt of the milestones is outside the control of the Company and contingent upon success in future clinical trials and the licensee’s efforts. Any consideration related to sales-based milestones (including royalties) will be recognized when the related sales occur as they were determined to relate predominantly to the license granted to Janssen and therefore have also been excluded from the transaction price. The Company will re-evaluate the transaction price in each reporting period and as uncertain events are resolved or other changes in circumstances occur.

For the years ended December 31, 2018, 2017 and 2016, we have recognized revenues totaling CHF 2.2 million, CHF 1.2 million and CHF 6.6 million, respectively.

Tau-PET imaging agent in AD –2014 agreement with Life Molecular Imaging (formerly Piramal Imaging SA)

In May 2014, AC Immune SA entered into an agreement, our first diagnostic partnership with Life Molecular Imaging (“Life Molecular”), the former Piramal Imaging SA. The partnership with Life Molecular is an exclusive, worldwide licensing agreement for the research, development and commercialization of the Company’s Tau protein positron emission tomography (PET) tracers supporting the diagnosis and clinical management of AD and potential Tau-related disorders and includes upfront and sales milestone payments totaling up to EUR 157 (CHF 179) million, plus royalties on sales at a percentage rate ranging from mid-single digits to low double digits.

Life Molecular may terminate this Agreement at any time after the first 18 months from the Effective Date of this Agreement upon 3 months prior written notice. If not otherwise terminated, the Agreement shall continue until the date of expiration of the last to expire Royalty Term.

In connection with this agreement, AC Immune received a EUR 500 (CHF 664) thousand payment which was fully recognized in 2015. In March 2017, we invoiced Life Molecular for a EUR 1.0 (CHF 1.1) million milestone related to the initiation of “Part B” of the first-in-man Phase 1 clinical trial for PSP (Progressive Supranuclear Palsy). As we met all performance obligations on reaching the milestone, we have recognized this milestone as revenue in the first quarter of fiscal 2017. The Company is eligible to receive variable consideration related to the achievement of certain clinical milestones totaling EUR 6 (CHF 7) million should the compound make it through to Phase 3 clinical studies. We are also eligible to receive potential regulatory and sales based milestones totaling EUR 150 (CHF 171) million. The Company is also eligible for royalties from the mid-single digits to low-double digits.

AC Immune assessed this arrangement in accordance with IFRS 15 and concluded that Life Molecular is a customer. The Company has identified that the right-to-use license as the only performance obligation. The Company determined that transaction price based on the defined terms allocated to each performance obligation specified in the contract.

The upfront payment constitutes the amount of consideration to be included in the transaction price and has been allocated to the license. None of the clinical, regulatory and commercial milestones have been included in the transaction price as these variable consideration elements are considered fully constrained. As part of its evaluation of the constraint, the Company considered numerous factors, including that receipt of the milestones is outside the control of the Company and contingent upon success in future clinical trials and the licensee’s efforts. Any consideration related to sales-based milestones (including royalties) will be recognized when the related sales occur as these amounts have been determined to relate predominantly to the license granted to Life Molecular and therefore are recognized at the later of when the performance obligation is satisfied or the related sales occur. The Company considered Life Molecular’s right to sublicense and develop the Tau Protein PET tracers, and the fact that Life Molecular could perform the research and development work themselves within the license term without AC Immune, to conclude that the license has stand-alone functionality and is distinct. The Company believes that the contracted amount represents the fair value. The Company will re-evaluate the transaction price in each reporting period and as uncertain events are resolved or other changes in circumstances occur.

In June 2018, Alliance Medical Group purchased Piramal Imaging SA. The Company was rebranded as Life Molecular Imaging. The Company’s Agreement will continue under the same terms and conditions with the new counterparty.

For the years ended December 31, 2018, 2017 and 2016, the Company has recognized nil, CHF 1.1 million and CHF 0.7 million, respectively.

Alpha-synuclein and TDP-43 PET tracers in AD – 2016 agreement with Biogen

On April 13, 2016, AC Immune entered into a non-exclusive research collaboration agreement with Biogen International GmbH, or Biogen. Under the agreement, we and Biogen have agreed to collaborate in the research and early clinical development of our alpha-synuclein PET tracer program for Parkinson’s disease and other synucleinopathies, and a second program for the identification, research and development of novel PET ligands against TDP-43, a protein recently linked to neurodegeneration in diseases such as amyotrophic lateral sclerosis. In addition, we have agreed to share the costs of the collaboration, with Biogen primarily funding the majority of research costs, subject to a cap, which includes an upfront technology access fee and funding towards research and development personnel. We will own all intellectual property rights to any invention relating to alpha-synuclein or TDP-43 PET tracers. The collaboration shall expire in April 2019.

AC Immune assessed this arrangement in accordance with IFRS 15 and concluded that Biogen is a customer. The Company has identified two performance obligations in our Biogen collaboration: (i) technology access fee and (ii) research and development services. The Company determined the transaction price based on the defined terms allocated to each performance obligation specified in the contract. In instances where the Company is reimbursed for research and development contributions procured from third parties such as negotiated terms with clinical research organizations, AC Immune records revenues for such services as it is acting as a principal in procuring the goods or services. The Company has the primary responsibility for fulfilling the promise to provide the specified good or service, it has inventory risk before transfer to the customer and it has discretion in negotiating the price with third parties. For other research and development services, revenues are recognized as work is performed, which correspond with, and best depict the transfer of control to the customer in line with the terms outlined in the contract.

We began a first-in-human study of our alpha-synuclein PET tracer in Q3 2018 and completed the second year and commenced the third year of our collaboration in April 2018. As of December 31, 2018, the Company has fully recognized revenues associated with the technology access fee. For the years ended December 31, 2018, 2017 and 2016, the Company has recognized CHF 4.0 million, CHF 3.9 million and CHF 2.1 million, respectively.

Recombinant protein therapeutic candidate –2017 agreement with Essex Bio-Technology Limited

On May 19, 2017, we entered into a Research Project Agreement with Essex Bio-Technology Limited, or Essex, to develop a recombinant protein therapeutic candidate acting on a unique neuroprotective mechanism for treatment of neurological diseases, such as Alzheimer’s disease and frontotemporal dementia. Essex will provide joint research commitment as well as financial support to AC Immune for the pre-IND development of the biological agent.

Subject to the terms of this Agreement, Essex Bio and the Company have the right to terminate by providing 60 days’ notice to the other Party. Otherwise, the Agreement shall remain in force until the later of the (i) completion of the Research and Development program or (ii) five years from the Effective date.

As part of this agreement, the parties have agreed to an initial two-year Research Plan, which intends to develop a basic Fibroblast Growth Factor (“bFGF”) as a therapeutic for the treatment of neurodegenerative diseases and to generate novel antibody therapeutics.

AC Immune assessed this arrangement in accordance with IFRS 15 and concluded that Essex Bio-Technology is a customer. AC Immune has identified that its performance obligation is for Full Time Employees to provide research support.

The transaction price consists of the contractual amounts to recognize for the full-time employee charges. For the full-time employee charges, we recorded revenues throughout the period based on the contractual rates over the service period as this best depicts the transfer of control to Essex. For the years ended December 31, 2018, 2017 and 2016, the Company has recognized CHF 0.7 million, less than CHF 0.1 million and nil, respectively. The length of the initial contract is five years through May 2022. Subject to the progress of the project, the Company may expect to recognize approximately CHF 0.8 million annually through the end of the contract.

Continuation of 2015 Grant from the Michael J. Fox Foundation

On September 16, 2017, AC Immune formally signed a grant continuation with the Michael J. Fox Foundation for Parkinson’s disease research (“MJFF”). This grant provides funds for the development of Positron Emission Tomography (PET) tracers for the alpha-synuclein protein, to support the early diagnosis and clinical management of Parkinson’s disease.

As part of this agreement, the MJFF expects that AC Immune will complete tasks according to the agreed timeline. AC Immune’s funding is variable depending on the satisfactory achievement of specific tasks. The Company identified four milestones to achieve but these are outputs of the Company’s services to perform and develop its PET tracer over a 12 month period. The services themselves over time are considered the performance obligation and not each a distinct performance obligation. Therefore, AC Immune has determined it has one performance obligation in the arrangement: the research services in support of the development of the alpha-synuclein PET tracer.

The transaction price consists of the contractual amount of CHF 380 thousand which is allocated to the services performed. However, the consideration is variable dependent upon AC Immune’s completion of key milestones. Using the most likely amount method, AC Immune assessed the project funding and likelihood of milestone obtainment. Management estimated a 100% likelihood of completing all milestones under the terms of the grant and no discount of the transaction price is taken. The Company therefore recognizes the revenues associated with this grant as services are performed. Quarterly, the Company estimates its progress and whether to constrain further revenue recognition.

For the years ended December 31, 2018, 2017 and 2016, the Company has recognized 0.3 million, CHF 0.1 million and nil, respectively. The Company has recorded all revenues from this grant through December 31, 2018.

Following the successful completion of this grant extension in 2018, we received an additional grant in November 2018 to conduct a first-in-human (FIH) study in H1 2019. No revenues were recorded as of December 31, 2018.

Expenses by category

12 Months Ended

Dec. 31, 2018

Expenses by category [Abstract]

Expenses by category

12.

Expenses by Category

Research and Development

	For the Years Ended December 31,
in CHF thousands	2018		2017		2016
Operating expenses		32,921		23,822		18,767
Payroll expenses		10,662		8,552		6,450
Share-based compensation		694		289		557
Total research and development expenses		44,277		32,663		25,774

General and Administrative

	For the Years Ended December 31,
in CHF thousands	2018		2017		2016
Operating expenses		4,903		3,857		3,168
Payroll expenses		5,740		4,984		3,969
Share-based compensation		1,824		1,290		759
Total general and administrative expenses		12,467		10,131		7,896

Financial Result, net

	For the Years Ended December 31,
in CHF thousands	2018			2017			2016
Interest income/ (expense)		(269	)		184			36
Foreign currency remeasurement gain/(loss), net		(1,194	)		(4,049	)		3,443
Other finance income/(expense)		62			(7	)		(119	)
Finance result, net		(1,401	)		(3,872	)		3,360

Related-party transactions

12 Months Ended

Dec. 31, 2018

Related-party transactions

13.

Related-party transactions

Key management, including the Board of Directors (seven individuals excluding the CEO) and the Executive Management (four individuals including the CEO), compensation was:

	For the Years Ended December 31,
in CHF thousands	2018		2017		2016
Short-term employee benefits		2,681		2,463		2,251
Post-employment benefits		160		166		154
Share-based compensation		1,683		1,267		832
Total		4,524		3,896		3,237

Short-term employee benefits comprise of salaries, bonuses, social security and expense allowances. On December 6, 2018, our former CSO Dr. Andreas Muhs passed away. His salary, bonus, social security and expense allowance for his time as a member of our Executive Management team have been included in the reconciliation above within short-term employee benefits and post-employment benefits.

On July 31, 2018, as part of the Company’s previously announced second subscription rights offering, a major shareholder and members of the Board and Executive Management purchased an aggregate of 614,147 of the Company’s common shares on the same basis and otherwise on the same terms as the other participants in such rights offering.

Income taxes

12 Months Ended

Dec. 31, 2018

Income taxes [Abstract]

Income taxes

14.

Income taxes

The Company recognized no income tax expense or deferred tax asset or liability positions for the years ended December 31, 2018, 2017, and 2016.

The income tax expense for each year can be reconciled to loss before tax as follows:

	For the Years Ended December 31,
in CHF thousands	2018			2017			2016
Loss before income tax		(50,951	)		(26,411	)		(7,096	)
Tax benefit calculated at the statutory rate of 20.6% (20.5% for 2017 and 21% for 2016)		(10,507	)		(5,420	)		(1,504	)
Permanent differences		334			40			(166	)
Effect of unrecognized carry forward tax loss		—			—			—
Effect of unused tax losses and tax offsets not recognized as deferred tax assets		10,173			5,380			1,670
Effective income tax rate benefit / (expense)		—			—			—

The tax rate used for the 2018 reconciliations above is the corporate tax rate of 20.6% (20.5%: 2017 and 21%: 2016) payable by corporate entities in the Canton of Vaud, Switzerland on taxable profits under tax law in that jurisdiction.

	As of December 31,
in CHF thousands	2018		2017		2016
Unrecognized deductible temporary differences, unused tax losses and unused tax credits
Deductible temporary differences, unused tax losses and unused tax credits for which no deferred tax assets have been recognized are attributable to the following:
- Tax losses		109,294		62,575		36,707
- Deductible temporary differences related to the retirement benefit plan		5,665		4,926		3,798

Total		114,959		67,501		40,505

Deductible temporary differences related to the retirement benefit plan do not expire. Tax losses expiry dates are shown in the table below:

	As of December 31,
in CHF thousands	2018		2017		2016
Tax losses split by expiry date
December 31, 2018				2,175		2,175
December 31, 2019		16,566		16,566		16,566
December 31, 2020		10,338		10,338		10,338
December 31, 2021		—		—		—
December 31, 2022		—		—		—
December 31, 2023		7,628		7,628		7,628
December 31, 2024		25,868		25,868		—
December 31, 2025		48,894		—		—
Total		109,294		62,575		36,707

The tax losses available for future offset against taxable profits have increased by CHF 48.9 million from 2017, representing the amount of tax losses that are additionally available as an offset reduced by expiring tax losses in 2018, subject to expiration as disclosed in the table above, against future taxable income.

Consistent with prior years, the Company has not recorded any deferred tax assets in relation to the past tax losses available for offset against future profits as the recognition criteria have not been met at the balance sheet date.

Retirement benefit plan

12 Months Ended

Dec. 31, 2018

Retirement benefit plan [Abstract]

Retirement benefit plan

15.

Retirement benefit plan

The Company participates in a collective foundation covering all of its employees including its executive officers. In addition to retirement benefits, the plan provides death or long-term disability benefits.

Contributions paid to the plan are computed as a percentage of salary, adjusted for the age of the employee and shared approximately 47% and 53% by employee and employer, respectively.

This plan is governed by the Swiss Law on Occupational Retirement, Survivors and Disability Pension Plans (BVG), which requires contributions to be made to a separately administered fund. The fund has the legal form of a foundation and it is governed by the board of trustees, which consists of an equal number of employer’s and employee’s representatives. The board of trustees is responsible for the administration of the plan assets and for the definition of the investment strategy.

The collective foundation is governed by a foundation board. The board is made up of an equal number of employee and employer representatives of the different affiliated companies. The Company has no direct influence on the investment strategy of the foundation board.

The assets are invested by the pension plan, to which many companies contribute, in a diversified portfolio that respects the requirements of the Swiss BVG. Therefore disaggregation of the pension assets and presentation of plan assets in classes that distinguish the nature and risks of those assets is not possible. Under the Plan, both the Company and the employee share the costs equally. The structure of the plan and the legal provisions of the BVG mean that the employer is exposed to actuarial risks. The main risks are investment risk, interest risk, disability risk and the life expectancy of pensioners. Through our affiliation with the pension plan, the Company has minimized these risks, since they are shared between a much greater number of participants. On leaving the Company, a departing employee’s retirement savings are transferred to the pension institution of the new employer or to a vested benefits institution. This transfer mechanism may result in pension payments varying considerably from year to year.

The pension plan is exposed to Swiss inflation, interest rate risks and changes in the life expectancy for pensioners. For accounting purposes under IFRS, the plan is treated as a defined benefit plan.

The following table sets forth the status of the defined benefit pension plan and the amount that should be recognized in the balance sheet:

	As of December 31,
in CHF thousands	2018			2017			2016
Defined benefit obligation		(17,942	)		(14,278	)		(11,596	)
Fair value of plan assets		12,277			9,352			7,798
Total liability		(5,665	)		(4,926	)		(3,798	)

The following amounts have been recorded as net pension cost in the statement of income:

	For the Years Ended December 31,
in CHF thousands	2018			2017			2016
Service cost		1,095			912			742
Interest cost		100			81			75
Interest income		(65	)		(55	)		(56	)
Net pension cost		1,130			938			761

The changes in defined benefit obligation, fair value of plan assets and unrecognized (gains) / losses are as follows:

Change in defined benefit obligation

	For the Years Ended December 31,
in CHF thousands	2018			2017			2016
Defined benefit obligation as of January 1		(14,278	)		(11,596	)		(9,439	)
Service cost		(1,095	)		(912	)		(742	)
Interest cost		(100	)		(81	)		(75	)
Change in demographic assumptions		—			—			(389	)
Change in financial assumptions		750			—			(26	)
Change in experience assumptions		(888	)		(735	)		(378	)
Benefit payments		(1,710	)		(426	)		(111	)
Employees’ contributions		(621	)		(528	)		(436	)
Defined benefit obligation as of December 31		(17,942	)		(14,278	)		(11,596	)

Change in fair value of plan assets

	For the Years Ended December 31,
in CHF thousands	2018			2017			2016
Fair value of plan assets as of January 1		9,352			7,798			6,652
Interest income		65			55			56
Employees’ contributions		621			528			436
Employer’s contributions		693			590			511
Benefits payments		1,710			426			111
Plan assets gains/(losses)		(164	)		(45	)		32
Fair value of plan assets as of December 31		12,277			9,352			7,798

Expected contributions by the employer to be paid to the post-employment benefit plans during the annual period beginning after the end of the reporting period amount to approximately CHF 788 thousand.

Change in net defined benefit liability

	For the Years Ended December 31,
in CHF thousands	2018			2017			2016
Net defined benefit liabilities as of January 1		4,926			3,798			2,787
Net pension cost through statement of income		1,130			938			761
Re-measurement through other comprehensive loss		302			780			761
Employer’s contribution		(693	)		(590	)		(511	)
Net defined benefit liabilities as of December 31		5,665			4,926			3,798

Change in other comprehensive loss

	For the Years Ended December 31,
in CHF thousands	2018			2017			2016
Other comprehensive loss as of January 1		(3,981	)		(3,201	)		(2,440	)
Effect of changes in demographic assumptions		—			—			(389	)
Effect of changes in financial assumptions		750			—			(26	)
Effect of changes in experience assumptions		(888	)		(735	)		(378	)
Plan assets gains/(losses)		(164	)		(45	)		32
Other comprehensive loss as of December 31		(4,283	)		(3,981	)		(3,201	)

The fair value of the plan assets is the cash surrender value of the insurance with AXA. The investment strategy defined by the board of trustees follows a conservative profile.

The plan assets are primarily held within instruments with quoted market prices in an active market, with the exception of real estate and mortgages.

The weighted average duration of the defined benefit obligation is 20.5 years as of December 31, 2018 and 2017 respectively.

The actuarial assumptions used for the calculation of the pension cost and the defined benefit obligation of the defined benefit pension plan for the year 2018, 2017 and 2016 are as follows:

	For the Years Ended December 31,
	2018			2017			2016
Discount rate		0.90	%		0.70	%		0.70	%
Rate of future increase in compensations		1.50	%		1.50	%		1.50	%
Rate of future increase in current pensions		0.50	%		0.50	%		0.50	%
Mortality and disability rates	BVG 2015G			BVG 2015G			BVG 2015G

In defining the benefits, the minimum requirements of the Swiss Law on Occupational Retirement, Survivors and Disability Pension Plans (BVG) and its implementing provisions must be observed. The BVG defines the minimum pensionable salary and the minimum retirement credits.

A quantitative sensitivity analysis for significant assumption as of December 31, 2018 is as shown below:

	Discount rate					Future salary increase					Future pension cost
Assumptions	+0.5% increase		-0.5% decrease			+0.5% increase			-0.5% decrease		+0.5% increase			-0.5% decrease
	in CHF thousands
Defined benefit obligation		16,250		19,906			18,475			17,441		18,826			17,346
Impact on the net defined benefit obligation		1,692		(1,964	)		(533	)		501		(884	)		596

The sensitivity analyses above is subject to limitations and has been determined based on a method that extrapolates the impact on net defined benefit obligation as a result of reasonable changes in key assumptions occurring at the end of the reporting period.

Share-based compensation

12 Months Ended

Dec. 31, 2018

Share-based compensation [Abstract]

Share-based compensation

16.

Share-based compensation

Share based option awards

Through the year ended December 31, 2018, there are equity-based instruments outstanding that the Company has granted under four different plans.

The Company’s 2016 Share Option and Incentive Plan (“Plan”) was approved by the shareholders at the Ordinary Shareholder’s meeting in November 2016. The 2016 Plan authorizes the grant of incentive and non-qualified share options, share appreciation rights, restricted share awards, restricted share units, unrestricted share awards, performance share awards, performance-based awards to covered employees and dividend equivalent rights. The Company only grants equity-based instruments from this Plan as of December 31, 2018.

The following table summarizes equity settled share option grants since inception under each plan:

PLAN	Number of options awarded (since inception)		Vesting conditions	Contractual life of options
Share option plan A		362,750	At grant	15.5 years
Share option plan B		819,000	At grant	10.5 years
Share option plan C1		6,775,250	4 years’ service from grant date	10 years
2016 Share Option and Incentive Plan:
Executives and Directors		538,764	4 years’ service from the date of grant, quarterly	10 years
Employees		222,405	4 years’ service from the date of grant, annually	10 years

The number and weighted average exercise prices (in CHF) of options under the share option programs for Plans A, B, C1 and 2016 share option and incentive plan are as follows:

	Number of Options			Weighted Average Exercise Price (CHF)		Weighted Average Remaining Term (Years)
Outstanding at January 1, 2016		3,597,000			0.15		3.6
Forfeited during the year		(106,000	)		0.15		—
Cancelled during the year		(19,250	)		0.15		—
Exercised during the year		(2,069,100	)		0.15		—
Granted during the year		285,250			0.15		—
Outstanding at December 31, 2016		1,687,900			0.15		5.6
Exercisable at December 31, 2016		1,284,525			0.15		6.5
Outstanding at January 1, 2017		1,687,900			0.15		5.6
Forfeited during the year		(1,750	)		0.15		—
Cancelled during the year		(31,250	)		0.15		—
Exercised during the year		(571,775	)		0.15		—
Granted during the year		276,766			9.70		—
Outstanding at December 31, 2017		1,359,891			2.09		5.8
Exercisable at December 31, 2017		900,474			0.39		4.3
Outstanding at January 1, 2018		1,359,891			2.09		5.8
Forfeited during the year		(73,624	)		9.16		—
Exercised during the year		(151,814	)		0.15		—
Granted during the year		484,403			9.79		—
Outstanding at December 31, 2018		1,618,856			4.25		6.3
Exercisable at December 31, 2018		932,175			1.25		4.4

The outstanding stock options as of December 31, 2018 have the following range of exercise prices. In fiscal year 2018, we began to grant awards solely with USD denominated exercise prices and discontinued granting awards with a CHF denominated exercise price.

Range of Exercise Prices	Total Options		Range of Expiration Dates
CHF 0.15		924,166		2020-2026
CHF 9.53		234,355		2027
USD 8.33 to USD 12.30		460,335		2028
Total outstanding options		1,618,856

We deemed 18,850 USD-denominated awards granted in 2017 despite the formal grant notice dated January 1, 2018. These awards are included as granted in 2017 and were translated from USD 12.30 to CHF 12.00 in 2017 for disclosure.

The weighted average exercise price for options granted in 2018, 2017 and 2016 is USD 9.97 (CHF 9.79), CHF 9.70 and CHF 0.15, respectively. The range of exercise prices for outstanding options was CHF 0.15 to CHF 9.53 for awards previously granted in CHF and USD 8.33 to USD 12.30 for awards granted in USD as of December 31, 2018.

Prior to the IPO, the exercise price was set by the Board of Directors. The volatility is based on the historical trend of an appropriate sample of companies operating in the biotech and pharmaceutical industry. The risk-free interest rate is based on the CHF swap rate for the expected life of the option. The weighted average share price of common share options exercised in 2018 is USD 9.92.

The weighted average grant date fair values of the options granted in 2018, 2017 and 2016 are USD 6.66 (CHF 6.54), CHF 7.29, and CHF 5.85, respectively. The following table illustrates the weighted-average assumptions for the Black-Scholes option-pricing model used in determining the fair value of these awards:

	For the Years Ended December 31,
	2018			2017			2016
Exercise price	USD 8.33-12.30			CHF 9.53-12.00			CHF 0.15
Share Price (weighted average)		9.87			8.77			5.96
Risk-free interest rate		0	%		0	%		0	%
Expected volatility		80	%		80	%		80	%
Expected term	6 years			6 years			6 years
Dividend yield		—			—			—

The expense charged against the income statement was CHF 2,518 thousand, CHF 1,579 thousand and CHF 1,317 thousand for the years ended December 31, 2018, 2017 and 2016, respectively. The expense is revised by the Company based on the number of instruments that are expected to become exercisable. The 2016 expense also reflects a share based option award that was modified in 2016 to amend the option grant’s contractual life and the issuance of a replacement award. An incremental fair value of CHF 238 thousand was immediately recognized in 2016 as a result of the modification of the share options contractual life. Additionally, in connection with former CFO departure in the fourth quarter of 2016, the former Chief Financial Officer forfeited his initial 2016 grant (included in the aggregate 2016 total of 98,500), and in its place was awarded 49,250 options, which has been accounted for as a new award granted on the date of forfeiture of the original award. The fourth quarter 2016 grant date fair value of the replacement award was CHF 674 thousand. The fair value of the modified award was measured using the Black-Scholes option pricing model with similar assumptions to the 2016 option, except for a currently quoted common share price as of the date of the modification.

Restricted share awards

A summary of non-vested share awards (restricted share and restricted share units) activity as of December 31, 2018 and changes during the year then ended is presented below:

Grantee Type	Number of non-vested share awards granted		Vesting conditions	Contractual life of non-vested share awards
Restricted Share Units
Directors		83,864	1 year service from date of grant, annually	10 years
Executives		110,839	4 years’ service from the date of grant, quarterly	10 years
Restricted Share Awards		4,023	2.75 years’ service from date of grant, quarterly	10 years

	Number of non-vested shares			Weighted average grant date fair value
Non-vested at December 31, 2017		122,014			9.59
Forfeited during the year		(25,673	)		9.48
Granted during the year		69,371			9.43
Vested during the year		(56,671	)		9.60
Non-vested at December 31, 2018		109,041			9.51
Vested and expected to vest at December 31, 2018		64,012			9.65

The weighted average grant date fair value of the restricted share awards granted (restricted shares and restricted share units) was CHF 9.43 and CHF 9.62 for the years ended December 31, 2018 and 2017 respectively. The weighted average grant date fair values of the non-vested share awards as of the respective year end (restricted shares and restricted share units) was CHF 9.51 and CHF 9.59 for the years ended December 31, 2018 and 2017, respectively. These fair values of non-vested share awards granted have been determined using a reasonable estimate of market value of the common stock on the date of the award.

Commitments and contingencies

12 Months Ended

Dec. 31, 2018

Commitments and contingencies [Abstract]

Commitments and contingencies

17.

Commitments and contingencies

In the normal course of business, we conduct product research and development programs through collaborative programs that include, among others, arrangements with universities, contract research organizations and clinical research sites. We have contractual arrangements with these organizations. As of December 31, 2018, external research projects included in the schedule below for 2019 total CHF 18.8 million that have been committed.

We lease our corporate, laboratory and other facilities under multiple operating leases at the EPFL Innovation Park in Ecublens, near Lausanne, Canton of Vaud, Switzerland. Our lease agreements have no termination clauses longer than a 12-month contractual notice period. Rental expense for the years ended December 31, 2018, 2017 and 2016 was CHF 0.8 million, 0.5 million and CHF 0.4 million, respectively. As of December 31, 2018, rental contracts for CHF 0.8 million were committed for 2019.

	As of December 31,
in CHF thousands	2018		2017
Within one year		19,880		9,686
Between one and three years		6,995		2,546
Between three and five years		5,009		140
More than five years		1,190		—
Total		33,074		12,372

Earnings per share

12 Months Ended

Dec. 31, 2018

Earnings per share [Abstract]

Earnings per share

18.

Earnings per share

	For the Years Ended December 31,
in CHF thousands except for share and per share data	2018			2017			2016
Net income / (loss) attributable to owners of the Company		(50,951	)		(26,411	)		(7,096	)
Earnings per share (EPS):
Basic and diluted, income / (loss) for the period attributable to equity holders		(0.82	)		(0.46	)		(0.14	)
Weighted-average number of shares used to compute EPS basic and diluted		61,838,228			57,084,295			50,096,859

Since we have a loss for all periods presented, basic net loss per share is the same as diluted net loss per share. We have excluded from our calculation of diluted loss per share all potentially dilutive in-the-money (i) share options and (ii) restricted share awards as the inclusion of these awards would have been anti-dilutive. Potentially dilutive securities that were not included in the diluted per share calculations because they would be anti-dilutive were as follows:

	As of December 31,
	2018		2017		2016
Share options issued and outstanding (in-the-money)		1,472,589		1,341,042		1,687,900
Restricted share awards subject to future vesting		109,041		122,014		—
Total		1,581,630		1,463,056		1,687,900

Financial instruments and risk management

12 Months Ended

Dec. 31, 2018

Financial instruments and risk management [Abstract]

Financial instruments and risk management

19.

Financial instruments and risk management

The Company’s activities expose it to the following financial risks: market risk (foreign exchange and interest rate risk), credit risk and liquidity risk. The Company’s overall risk management program focuses on the unpredictability of financial markets and seeks to minimize potential adverse effects on the Company’s financial performance.

The following table shows the carrying amounts of financial assets and financial liabilities:

	As of December 31,
in CHF thousands	2018		2017
Financial assets
Long-term financial assets		304		126
Other current receivables		236		918
Short-term financial assets		30,000		—
Cash and cash equivalents		156,462		124,377
Total financial assets		187,002		125,421

	As of December 31,
in CHF thousands	2018		2017
Financial liabilities
Short-term debt obligation		332		—
Long-term debt obligation		186		494
Trade and other payables		1,979		1,092
Accrued expenses		10,420		8,307
Total financial liabilities		12,917		9,893

Foreign exchange risk

The Company is exposed to foreign exchange risk arising from currency exposures, primarily with respect to the EUR, USD and to a lesser extent to GBP, DKK and SEK. The currency exposure is not hedged. However, the Company has a policy of matching its cash holdings to the currency structure of its expenses, which means that the Company holds predominately CHF, EUR and USD (see also Note 5). In the Company’s income statements for the years ended December 31, 2018, 2017 and 2016 a loss of CHF 1.2 million, a loss of CHF 4.2 million and a gain of CHF 3.4 million respectively, is recognized in the financial statement line item “Finance result, net.”

As of December 31, 2018, if the CHF had strengthened/weakened by 10% against the EUR and the USD with all other variables held constant, the net loss for the period would have been lower/higher by CHF 3.0 million (2017: CHF 2.1 million), mainly as a result of foreign exchange gains/losses on predominantly EUR/USD denominated cash and cash equivalents and short-term financial assets.

Interest rates

The Company’s CHF cash holdings (inclusive of those held in short-term financial assets) are subject to negative interest rates at certain counterparty thresholds. As of December 31, 2018, if the interest rates charged by the counterparties had increased/decreased by 10%, the net loss for the period would have been higher/lower by less than CHF 0.1 million. Interest income and interest expense are recorded within Finance results, net in our statements of loss.

Credit risk

The Company maintains a formal treasury risk and investment management policy to limit counterparty credit risk. As of December 31, 2018, the Company’s cash and cash equivalents and short-term financial assets are held with three financial institutions each with a high credit-rating assigned by international credit-rating agencies. The maximum amount of credit risk is the carrying amount of the financial assets. Trade and other receivables are fully performing, not past due and not impaired (see Notes 5 and 7).

Liquidity risk

Inherent in the Company’s business are various risks and uncertainties, including its limited operating history and the high uncertainty that new therapeutic concepts will succeed. AC Immune’s success may depend in part upon its ability to (i) establish and maintain a strong patent position and protection, (ii) enter into collaborations with partners in the biotech and pharmaceutical industry, (iii) acquire and keep key personnel employed, and (iv) acquire additional capital to support its operations.

The Company’s approach of managing liquidity is to ensure sufficient cash to meet its liabilities when due. Therefore, management closely monitors the cash position on rolling forecasts based on expected cash flow to enable the Company to finance its operations for at least 18 months. The Company has a debt obligation due to LuMind and projects CHF 332 thousand to be paid within 12 months and CHF 186 thousand to be paid within 12-24 months from the reporting date. See Note 10 “Debt obligation” for further details.

Capital risk management

12 Months Ended

Dec. 31, 2018

Capital risk management [Abstract]

Capital risk management

20.

Capital risk management

The Company’s objectives when managing capital are to safeguard the Company’s ability to continue as a going concern and to preserve the capital on the required statutory level in order to succeed in developing a cure against Alzheimer’s disease.

Quarterly Financial Results (Unaudited)

12 Months Ended

Dec. 31, 2018

Quarterly Financial Results (Unaudited) [Abstract]

Quarterly Financial Results (Unaudited)

21.

Quarterly Financial Results (Unaudited)

The following tables set forth certain unaudited condensed quarterly financial data for each of the four quarters in the periods ended December 31, 2018 and 2017, respectively. The Company believes that the following information reflects all normal recurring adjustments necessary for a fair statement of the information for the periods presented. The operating results for any quarter are not necessarily indicative of results for any future period.

	For the Three Months Ended
	Dec. 31, 2018			Sep. 30, 2018			Jun. 30, 2018			Mar. 31, 2018
	(in CHF thousands, except per share data) (unaudited)
Revenue
Contract revenue		1,403			2,305			2,028			1,458
Total revenue		1,403			2,305			2,028			1,458

Operating expenses
Research and development expenses		(12,129	)		(11,546	)		(10,533	)		(10,069	)
General and administrative expenses		(3,761	)		(2,930	)		(3,065	)		(2,711	)
Total operating expenses		(15,890	)		(14,476	)		(13,598	)		(12,780	)
Operating income/(loss)		(14,487	)		(12,171	)		(11,570	)		(11,322	)
Finance result, net		(191	)		(1,345	)		427			(292	)
Income/(loss) before tax		(14,678	)		(13,516	)		(11,143	)		(11,614	)
Income tax expense		-			-			-			-
Income/(loss) for the period		(14,678	)		(13,516	)		(11,143	)		(11,614	)
Net income/(loss) per share (EPS):
Basic and diluted		(0.22	)		(0.21	)		(0.19	)		(0.20	)
Weighted-average number of shares used to compute EPS:
Basic and diluted		67,553,262			64,862,822			57,423,650			57,368,015

	For the Three Months Ended
	Dec. 31, 2017			Sep. 30, 2017			Jun. 30, 2017			Mar. 31, 2017
	(in CHF thousands, except per share data) (unaudited)
Revenue
Contract revenue		16,422			1,074			753			2,006
Total revenue		16,422			1,074			753			2,006

Operating expenses
Research and development expenses		(10,176	)		(8,195	)		(6,838	)		(7,454	)
General and administrative expenses		(3,058	)		(2,519	)		(2,168	)		(2,386	)
Total operating expenses		(13,234	)		(10,714	)		(9,006	)		(9,840	)
Operating income/(loss)		3,188			(9,640	)		(8,253	)		(7,834	)
Finance result, net		976			847			(4,074	)		(1,621	)
Income/(loss) before tax		4,164			(8,793	)		(12,327	)		(9,455	)
Income tax expense		-			-			-			-
Income/(loss) for the period		4,164			(8,793	)		(12,327	)		(9,455	)
Net income/(loss) per share (EPS):
Basic		0.07			(0.15	)		(0.22	)		(0.17	)
Diluted		0.07			(0.15	)		(0.22	)		(0.17	)
Weighted-average number of shares used to compute EPS:
Basic		57,266,088			57,164,145			57,048,187			56,855,987
Diluted		58,396,586			57,164,145			57,048,187			56,855,987

Post balance sheet events

12 Months Ended

Dec. 31, 2018

Post balance sheet events [Abstract]

Post balance sheet events

22.

Post balance sheet events

On January 23, 2019, the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, expired with regard to our license agreement with Eli Lilly and Company (“Lilly”), which we signed in December 2018. Under the terms of the license agreement, the Company will conduct initial Phase 1 development of Tau Morphomer small molecules. Lilly will fund and lead further clinical development and will receive global commercialization rights for all indications, including Alzheimer’s disease and other neurodegenerative diseases. The Company will retain certain development rights in orphan indications and co-development and co-promotion options in certain indications outside Alzheimer’s disease.

The agreement also allows for potential development of indications in Progressive Supranuclear Palsy and an exclusive license to Lilly of certain intellectual property related to this program.

The Company received CHF 80 million as an upfront payment in February 2019. The agreement also includes various conditional clinical, regulatory and commercialization milestone payments. In addition, the Company will receive royalties on sales of licensed products.

The agreement will terminate on the date on which all obligations between the parties with respect to the last payment of royalties for licensed products have passed or expired. Subject to the terms in the agreement, Lilly may terminate the agreement with three months’ written notice to the Company

We and Lilly also entered into a convertible note agreement in December 2018, which also became effective on January 23, 2019. As the convertible note was not effective as of December 31, 2018, there is no corresponding recognition in our financial statements. The Company received total consideration of USD 50.0 (CHF 50.3) million in January 2019. The convertible note is a senior unsecured obligation of the Company that bears interest at a rate of 0.75% per annum, which may be paid in cash or result in the accretion of the principal amount thereof, at our election.

Subject to the terms and conditions set forth in the convertible note agreement, the convertible note will automatically convert into the Company’s common shares on the 90th day after the effective date of the license agreement, at a conversion price equal to USD 13.83 per share, which would convert into approximately 3.6 million of our common shares.

On January 30, 2019, we announced that Roche, the parent of our collaboration partner Genentech, is discontinuing the CREAD 1 and CREAD 2 (BN29552 and BN29553) Phase III studies of crenezumab in people with prodromal to mild sporadic AD. The decision came after an interim analysis conducted by the IDMC indicated that crenezumab was unlikely to meet its primary endpoint of change from baseline in Clinical Dementia Rating-Sum of Boxes (CDR-SB) Score. This decision was not related to safety of the investigational product. No safety signals for crenezumab were observed in this analysis and the overall safety profile was similar to that seen in previous trials.

Crenezumab continues to be studied in a preventive trial of cognitively healthy individuals in Colombia with an autosomal dominant mutation who are at risk of developing familial AD (fAD), under the Alzheimer’s Prevention Initiative (API), which began in 2013. This study will determine if treating people carrying this mutation with crenezumab prior to the onset of AD symptoms will slow or prevent the decline of cognitive and functional abilities. This study is in collaboration with the Banner Institute and is funded by the National Institute on Aging.

In March 2019, the Company and Biogen decided not to extend their collaboration agreement into a fourth year per the contract and conclude in April 2019 within the original three-year term of the agreement.

Summary of significant accounting policies (Policies)

12 Months Ended

Dec. 31, 2018

Summary of significant accounting policies [Abstract]

Current vs. non-current classification

Foreign currency transactions

Revenue recognition

License of intellectual property

Milestone payments

Research and Development Services

Contract Balances

Research and development services

Research and development expenditure

Given the stage of development of the Company’s products, all research expenditure is recognized as expense when incurred. Research and development expenditures include:

●

fees and costs related to regulatory filings and activities;

●

costs associated with pre-clinical and clinical activities; and

●

employee-related expenses, including salaries and bonuses, benefits, travel and stock-based compensation expense

Property, plant and equipment

IT equipment	3 years
Laboratory equipment	5 years
Leasehold improvements / furniture	5 years

Gains and losses on disposals are determined by comparing the disposal proceeds with the carrying amount and are included in the statements of loss.

Fair value of financial assets and liabilities

Receivables

Short-term financial assets

Short-term financial assets are held with external financial institutions and comprise fixed-term deposits with maturities ranging from more than 3 until 12 months in duration.

Cash and cash equivalents

The Company assesses at each period whether there is objective evidence that financial assets are impaired.

Trade payables

Trade payables are amounts due to third parties in the ordinary course of business.

Debt obligations

The Company’s debt obligations relate to its agreement with a third party and are measured as of the period end date based on the repayment terms when originated.

Share capital and public offering

Share capital and public offerings

Employee benefits

Post-employment benefits

Share-based compensation

The proceeds received net of any directly attributable transaction costs are credited to share capital (nominal value) and share premium when the options are exercised.

Critical judgments and accounting estimates

Income taxes

Segment reporting

The Company has one segment. The Company currently focuses all of its resources on discovering and developing therapeutic and diagnostic products targeting misfolded proteins.

Accounting pronouncements - not yet adopted

Accounting pronouncements – not yet adopted

The following pronouncements from the IASB will become effective for future financial reporting periods and have not yet been adopted by AC Immune.

Accounting pronouncements - recently adopted

Accounting pronouncements – recently adopted

IFRS 15 Revenue from Contracts with Customers

IFRS 9 Financial Instruments

Summary of significant accounting policies (Tables)

12 Months Ended

Dec. 31, 2018

Summary of significant accounting policies [Abstract]

Estimated useful life

Depreciation is calculated using a straight-line method to write off the cost of each asset to its residual value over its estimated useful life as follows:

IT equipment	3 years
Laboratory equipment	5 years
Leasehold improvements / furniture	5 years

Property, plant and equipment (Tables)

12 Months Ended

Dec. 31, 2018

Property, plant and equipment [Abstract]

Property, plant and equipment

in CHF thousands	Furniture			Computers /IT			Lab Equipment			Leasehold Improvements			Total
Acquisition Cost:
Balance at December 31, 2017		85			569			4,161			272			5,087
Acquisitions		41			456			1,357			78			1,932
Disposals		—			—			(151	)		—			(151	)
Balance at December 31, 2018		126			1,025			5,367			350			6,868

Accumulated depreciation:
Balance at December 31, 2017		(59	)		(259	)		(2,311	)		(105	)		(2,734	)
Depreciation expense		(18	)		(196	)		(697	)		(50	)		(961	)
Disposals		—			—			151			—			151
Balance at December 31, 2018		(77	)		(455	)		(2,857	)		(155	)		(3,544	)

Carrying Amount:
December 31, 2017		26			310			1,850			167			2,353
December 31, 2018		49			570			2,510			195			3,324

in CHF thousands	Furniture			Computers /IT			Lab Equipment			Leasehold Improvements			Total
Acquisition Cost:
Balance at December 31, 2016		81			298			2,792			103			3,274
Acquisitions		4			271			1,369			169			1,813
Balance at December 31, 2017		85			569			4,161			272			5,087

Accumulated depreciation:
Balance at December 31, 2016		(45	)		(172	)		(1,858	)		(79	)		(2,154	)
Depreciation expense		(14	)		(87	)		(453	)		(26	)		(580	)
Balance at December 31, 2017		(59	)		(259	)		(2,311	)		(105	)		(2,734	)

Carrying Amount:
December 31, 2016		36			126			934			24			1,120
December 31, 2017		26			310			1,850			167			2,353

Cash and cash equivalents and financial assets (Tables)

12 Months Ended

Dec. 31, 2018

Cash and cash equivalents and financial assets [Abstract]

Cash and cash equivalents and short-term financial assets

The following tables summarize the Company’s cash and cash equivalents and short-term financial assets as of December 31, 2018 and 2017:

	As of December 31,
in CHF thousands	2018		2017
Cash and cash equivalents		156,462		124,377
Total		156,462		124,377

	As of December 31,
in CHF thousands	2018		2017
Short-term financial assets due in one year or less		30,000		—
Total		30,000		—

The Company’s cash and cash equivalents are maintained in the following respective currencies as of December 31, 2018 and 2017:

	As of December 31,
in CHF thousands	2018		2017
Cash and cash equivalents		156,462		124,377
Total		156,462		124,377

By currency
CHF		126,218		103,272
EUR		11,471		3,658
USD		18,773		17,447
Total cash and cash equivalents		156,462		124,377

Prepaid expenses and accrued income (Tables)

12 Months Ended

Dec. 31, 2018

Prepaid expenses and accrued income [Abstract]

Prepaid expenses and accrued income

	As of December 31,
in CHF thousands	2018		2017
Prepaid expenses		2,364		1,440
Accrued income		3,667		2,799
Total		6,031		4,239

Other current receivables (Tables)

12 Months Ended

Dec. 31, 2018

Other current receivables [Abstract]

Other current receivables

	As of December 31,
in CHF thousands	2018		2017
Other receivables		17		691
Swiss VAT		209		112
Withholding tax		10		115
Total		236		918

Share capital (Tables)

12 Months Ended

Dec. 31, 2018

Share capital [Abstract]

Summary of capital structure

The table below summarizes the Company’s capital structure:

	Common Shares		in CHF thousands
	Number		Share Capital		Share Premium
December 31, 2016		56,773,392		1,135		188,166
Issuance of Shares – Incentive Plans		581,796		12		133

December 31, 2017		57,355,188		1,147		188,299
Issuance of Shares – Incentive Plans		207,145		4		537
Issuance of Shares – Public Offering (net of transaction costs)		10,000,000		200		109,313
December 31, 2018		67,562,333		1,351		298,149

Trade payables, accrued liabilities and deferred income (Tables)

12 Months Ended

Dec. 31, 2018

Trade payables, accrued liabilities and deferred income [Abstract]

Trade payables and accrued liabilities

	As of December 31,
in CHF thousands	2018		2017
Trade and other payables		1,979		1,092
Accrued research and development costs		6,803		5,430
Accrued payroll expenses		2,482		2,420
Other accrued expenses		1,135		457
Deferred income		351		355
Total		12,750		9,754

Revenues (Tables)

12 Months Ended

Dec. 31, 2018

Revenues [Abstract]

Changes in Contract Assets and Contract Liabilities

The following table presents changes in the Company’s contract assets and liabilities during the years ended December 31, 2018 and 2017 (in CHF thousands):

	Balance at the beginning of the reporting period		Additions		Deductions			Balance at the end of the reporting period
Twelve months ended December 31, 2018:
Accrued Income		2,799		5,846		(4,978	)		3,667
Deferred Income		355		1,533		(1,537	)		351

Twelve months ended December 31, 2017:
Accrued Income		889		3,813		(1,903	)		2,799
Deferred Income		521		1,250		(1,416	)		355

Revenues

	For the Years Ended December 31,
Revenues recognized in the period from:	2018		2017
Amounts included in the contract liability at the beginning of the period		1,551		1,401

	For the Years Ended December 31,
in CHF thousands, by partner	2018		2017		2016
Genentech		—		14,000		14,001
Janssen		2,157		1,239		6,628
Life Molecular Imaging		—		1,080		7
Biogen		4,024		3,930		2,100
Other		1,013		6		478
Total contract revenue		7,194		20,255		23,214

Expenses by category (Tables)

12 Months Ended

Dec. 31, 2018

Expenses by category [Abstract]

Research and Development

	For the Years Ended December 31,
in CHF thousands	2018		2017		2016
Operating expenses		32,921		23,822		18,767
Payroll expenses		10,662		8,552		6,450
Share-based compensation		694		289		557
Total research and development expenses		44,277		32,663		25,774

General and Administrative

	For the Years Ended December 31,
in CHF thousands	2018		2017		2016
Operating expenses		4,903		3,857		3,168
Payroll expenses		5,740		4,984		3,969
Share-based compensation		1,824		1,290		759
Total general and administrative expenses		12,467		10,131		7,896

Financial Result, net

	For the Years Ended December 31,
in CHF thousands	2018			2017			2016
Interest income/ (expense)		(269	)		184			36
Foreign currency remeasurement gain/(loss), net		(1,194	)		(4,049	)		3,443
Other finance income/(expense)		62			(7	)		(119	)
Finance result, net		(1,401	)		(3,872	)		3,360

Related-party transactions (Tables)

12 Months Ended

Dec. 31, 2018

Key management compensation

Key management, including the Board of Directors (seven individuals excluding the CEO) and the Executive Management (four individuals including the CEO), compensation was:

	For the Years Ended December 31,
in CHF thousands	2018		2017		2016
Short-term employee benefits		2,681		2,463		2,251
Post-employment benefits		160		166		154
Share-based compensation		1,683		1,267		832
Total		4,524		3,896		3,237

Income taxes (Tables)

12 Months Ended

Dec. 31, 2018

Income taxes [Abstract]

Income tax expense reconciled to loss

The income tax expense for each year can be reconciled to loss before tax as follows:

	For the Years Ended December 31,
in CHF thousands	2018			2017			2016
Loss before income tax		(50,951	)		(26,411	)		(7,096	)
Tax benefit calculated at the statutory rate of 20.6% (20.5% for 2017 and 21% for 2016)		(10,507	)		(5,420	)		(1,504	)
Permanent differences		334			40			(166	)
Effect of unrecognized carry forward tax loss		—			—			—
Effect of unused tax losses and tax offsets not recognized as deferred tax assets		10,173			5,380			1,670
Effective income tax rate benefit / (expense)		—			—			—

Unrecognized deductible temporary differences, unused tax losses and unused tax credits

	As of December 31,
in CHF thousands	2018		2017		2016
Unrecognized deductible temporary differences, unused tax losses and unused tax credits
Deductible temporary differences, unused tax losses and unused tax credits for which no deferred tax assets have been recognized are attributable to the following:
- Tax losses		109,294		62,575		36,707
- Deductible temporary differences related to the retirement benefit plan		5,665		4,926		3,798

Total		114,959		67,501		40,505

Tax losses expiry dates

Deductible temporary differences related to the retirement benefit plan do not expire. Tax losses expiry dates are shown in the table below:

	As of December 31,
in CHF thousands	2018		2017		2016
Tax losses split by expiry date
December 31, 2018				2,175		2,175
December 31, 2019		16,566		16,566		16,566
December 31, 2020		10,338		10,338		10,338
December 31, 2021		—		—		—
December 31, 2022		—		—		—
December 31, 2023		7,628		7,628		7,628
December 31, 2024		25,868		25,868		—
December 31, 2025		48,894		—		—
Total		109,294		62,575		36,707

Retirement benefit plan (Tables)

12 Months Ended

Dec. 31, 2018

Retirement benefit plan [Abstract]

Defined benefit pension plan amounts recognized in the balance sheet and statement of income

The following table sets forth the status of the defined benefit pension plan and the amount that should be recognized in the balance sheet:

	As of December 31,
in CHF thousands	2018			2017			2016
Defined benefit obligation		(17,942	)		(14,278	)		(11,596	)
Fair value of plan assets		12,277			9,352			7,798
Total liability		(5,665	)		(4,926	)		(3,798	)

The following amounts have been recorded as net pension cost in the statement of income:

	For the Years Ended December 31,
in CHF thousands	2018			2017			2016
Service cost		1,095			912			742
Interest cost		100			81			75
Interest income		(65	)		(55	)		(56	)
Net pension cost		1,130			938			761

Changes in defined benefit obligation, fair value of plan assets and unrecognized (gains) / losses

The changes in defined benefit obligation, fair value of plan assets and unrecognized (gains) / losses are as follows:

Change in defined benefit obligation

	For the Years Ended December 31,
in CHF thousands	2018			2017			2016
Defined benefit obligation as of January 1		(14,278	)		(11,596	)		(9,439	)
Service cost		(1,095	)		(912	)		(742	)
Interest cost		(100	)		(81	)		(75	)
Change in demographic assumptions		—			—			(389	)
Change in financial assumptions		750			—			(26	)
Change in experience assumptions		(888	)		(735	)		(378	)
Benefit payments		(1,710	)		(426	)		(111	)
Employees’ contributions		(621	)		(528	)		(436	)
Defined benefit obligation as of December 31		(17,942	)		(14,278	)		(11,596	)

Change in fair value of plan assets

	For the Years Ended December 31,
in CHF thousands	2018			2017			2016
Fair value of plan assets as of January 1		9,352			7,798			6,652
Interest income		65			55			56
Employees’ contributions		621			528			436
Employer’s contributions		693			590			511
Benefits payments		1,710			426			111
Plan assets gains/(losses)		(164	)		(45	)		32
Fair value of plan assets as of December 31		12,277			9,352			7,798

Change in net defined benefit liability

	For the Years Ended December 31,
in CHF thousands	2018			2017			2016
Net defined benefit liabilities as of January 1		4,926			3,798			2,787
Net pension cost through statement of income		1,130			938			761
Re-measurement through other comprehensive loss		302			780			761
Employer’s contribution		(693	)		(590	)		(511	)
Net defined benefit liabilities as of December 31		5,665			4,926			3,798

Change in other comprehensive loss

	For the Years Ended December 31,
in CHF thousands	2018			2017			2016
Other comprehensive loss as of January 1		(3,981	)		(3,201	)		(2,440	)
Effect of changes in demographic assumptions		—			—			(389	)
Effect of changes in financial assumptions		750			—			(26	)
Effect of changes in experience assumptions		(888	)		(735	)		(378	)
Plan assets gains/(losses)		(164	)		(45	)		32
Other comprehensive loss as of December 31		(4,283	)		(3,981	)		(3,201	)

Actuarial assumptions and sensitivity analysis

The actuarial assumptions used for the calculation of the pension cost and the defined benefit obligation of the defined benefit pension plan for the year 2018, 2017 and 2016 are as follows:

	For the Years Ended December 31,
	2018			2017			2016
Discount rate		0.90	%		0.70	%		0.70	%
Rate of future increase in compensations		1.50	%		1.50	%		1.50	%
Rate of future increase in current pensions		0.50	%		0.50	%		0.50	%
Mortality and disability rates	BVG 2015G			BVG 2015G			BVG 2015G

A quantitative sensitivity analysis for significant assumption as of December 31, 2018 is as shown below:

	Discount rate					Future salary increase					Future pension cost
Assumptions	+0.5% increase		-0.5% decrease			+0.5% increase			-0.5% decrease		+0.5% increase			-0.5% decrease
	in CHF thousands
Defined benefit obligation		16,250		19,906			18,475			17,441		18,826			17,346
Impact on the net defined benefit obligation		1,692		(1,964	)		(533	)		501		(884	)		596

Share-based compensation (Tables)

12 Months Ended

Dec. 31, 2018

Share-based compensation [Abstract]

Share-based compensation plans outstanding

The following table summarizes equity settled share option grants since inception under each plan:

PLAN	Number of options awarded (since inception)		Vesting conditions	Contractual life of options
Share option plan A		362,750	At grant	15.5 years
Share option plan B		819,000	At grant	10.5 years
Share option plan C1		6,775,250	4 years’ service from grant date	10 years
2016 Share Option and Incentive Plan:
Executives and Directors		538,764	4 years’ service from the date of grant, quarterly	10 years
Employees		222,405	4 years’ service from the date of grant, annually	10 years

Number and weighted average exercise prices of options under share option programs

The number and weighted average exercise prices (in CHF) of options under the share option programs for Plans A, B, C1 and 2016 share option and incentive plan are as follows:

	Number of Options			Weighted Average Exercise Price (CHF)		Weighted Average Remaining Term (Years)
Outstanding at January 1, 2016		3,597,000			0.15		3.6
Forfeited during the year		(106,000	)		0.15		—
Cancelled during the year		(19,250	)		0.15		—
Exercised during the year		(2,069,100	)		0.15		—
Granted during the year		285,250			0.15		—
Outstanding at December 31, 2016		1,687,900			0.15		5.6
Exercisable at December 31, 2016		1,284,525			0.15		6.5
Outstanding at January 1, 2017		1,687,900			0.15		5.6
Forfeited during the year		(1,750	)		0.15		—
Cancelled during the year		(31,250	)		0.15		—
Exercised during the year		(571,775	)		0.15		—
Granted during the year		276,766			9.70		—
Outstanding at December 31, 2017		1,359,891			2.09		5.8
Exercisable at December 31, 2017		900,474			0.39		4.3
Outstanding at January 1, 2018		1,359,891			2.09		5.8
Forfeited during the year		(73,624	)		9.16		—
Exercised during the year		(151,814	)		0.15		—
Granted during the year		484,403			9.79		—
Outstanding at December 31, 2018		1,618,856			4.25		6.3
Exercisable at December 31, 2018		932,175			1.25		4.4

Outstanding options, exercise price range and expiry dates

Range of Exercise Prices	Total Options		Range of Expiration Dates
CHF 0.15		924,166		2020-2026
CHF 9.53		234,355		2027
USD 8.33 to USD 12.30		460,335		2028
Total outstanding options		1,618,856

Weighted-average assumptions

	For the Years Ended December 31,
	2018			2017			2016
Exercise price	USD 8.33-12.30			CHF 9.53-12.00			CHF 0.15
Share Price (weighted average)		9.87			8.77			5.96
Risk-free interest rate		0	%		0	%		0	%
Expected volatility		80	%		80	%		80	%
Expected term	6 years			6 years			6 years
Dividend yield		—			—			—

Summary of non-vested share awards (restricted share and restricted share units)

A summary of non-vested share awards (restricted share and restricted share units) activity as of December 31, 2018 and changes during the year then ended is presented below:

Grantee Type	Number of non-vested share awards granted		Vesting conditions	Contractual life of non-vested share awards
Restricted Share Units
Directors		83,864	1 year service from date of grant, annually	10 years
Executives		110,839	4 years’ service from the date of grant, quarterly	10 years
Restricted Share Awards		4,023	2.75 years’ service from date of grant, quarterly	10 years

	Number of non-vested shares			Weighted average grant date fair value
Non-vested at December 31, 2017		122,014			9.59
Forfeited during the year		(25,673	)		9.48
Granted during the year		69,371			9.43
Vested during the year		(56,671	)		9.60
Non-vested at December 31, 2018		109,041			9.51
Vested and expected to vest at December 31, 2018		64,012			9.65

Commitments and contingencies (Tables)

12 Months Ended

Dec. 31, 2018

Commitments and contingencies [Abstract]

Maturity of commitments and contingencies

	As of December 31,
in CHF thousands	2018		2017
Within one year		19,880		9,686
Between one and three years		6,995		2,546
Between three and five years		5,009		140
More than five years		1,190		—
Total		33,074		12,372

Earnings per share (Tables)

12 Months Ended

Dec. 31, 2018

Earnings per share [Abstract]

Earnings per share

	For the Years Ended December 31,
in CHF thousands except for share and per share data	2018			2017			2016
Net income / (loss) attributable to owners of the Company		(50,951	)		(26,411	)		(7,096	)
Earnings per share (EPS):
Basic and diluted, income / (loss) for the period attributable to equity holders		(0.82	)		(0.46	)		(0.14	)
Weighted-average number of shares used to compute EPS basic and diluted		61,838,228			57,084,295			50,096,859

Antidilutive securities

Potentially dilutive securities that were not included in the diluted per share calculations because they would be anti-dilutive were as follows:

	As of December 31,
	2018		2017		2016
Share options issued and outstanding (in-the-money)		1,472,589		1,341,042		1,687,900
Restricted share awards subject to future vesting		109,041		122,014		—
Total		1,581,630		1,463,056		1,687,900

Financial instruments and risk management (Tables)

12 Months Ended

Dec. 31, 2018

Financial instruments and risk management [Abstract]

Carrying amounts of financial assets and financial liabilities

The following table shows the carrying amounts of financial assets and financial liabilities:

	As of December 31,
in CHF thousands	2018		2017
Financial assets
Long-term financial assets		304		126
Other current receivables		236		918
Short-term financial assets		30,000		—
Cash and cash equivalents		156,462		124,377
Total financial assets		187,002		125,421

	As of December 31,
in CHF thousands	2018		2017
Financial liabilities
Short-term debt obligation		332		—
Long-term debt obligation		186		494
Trade and other payables		1,979		1,092
Accrued expenses		10,420		8,307
Total financial liabilities		12,917		9,893

Quarterly Financial Results (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2018

Quarterly Financial Results (Unaudited) [Abstract]

Quarterly financial data

	For the Three Months Ended
	Dec. 31, 2018			Sep. 30, 2018			Jun. 30, 2018			Mar. 31, 2018
	(in CHF thousands, except per share data) (unaudited)
Revenue
Contract revenue		1,403			2,305			2,028			1,458
Total revenue		1,403			2,305			2,028			1,458

Operating expenses
Research and development expenses		(12,129	)		(11,546	)		(10,533	)		(10,069	)
General and administrative expenses		(3,761	)		(2,930	)		(3,065	)		(2,711	)
Total operating expenses		(15,890	)		(14,476	)		(13,598	)		(12,780	)
Operating income/(loss)		(14,487	)		(12,171	)		(11,570	)		(11,322	)
Finance result, net		(191	)		(1,345	)		427			(292	)
Income/(loss) before tax		(14,678	)		(13,516	)		(11,143	)		(11,614	)
Income tax expense		-			-			-			-
Income/(loss) for the period		(14,678	)		(13,516	)		(11,143	)		(11,614	)
Net income/(loss) per share (EPS):
Basic and diluted		(0.22	)		(0.21	)		(0.19	)		(0.20	)
Weighted-average number of shares used to compute EPS:
Basic and diluted		67,553,262			64,862,822			57,423,650			57,368,015

	For the Three Months Ended
	Dec. 31, 2017			Sep. 30, 2017			Jun. 30, 2017			Mar. 31, 2017
	(in CHF thousands, except per share data) (unaudited)
Revenue
Contract revenue		16,422			1,074			753			2,006
Total revenue		16,422			1,074			753			2,006

Operating expenses
Research and development expenses		(10,176	)		(8,195	)		(6,838	)		(7,454	)
General and administrative expenses		(3,058	)		(2,519	)		(2,168	)		(2,386	)
Total operating expenses		(13,234	)		(10,714	)		(9,006	)		(9,840	)
Operating income/(loss)		3,188			(9,640	)		(8,253	)		(7,834	)
Finance result, net		976			847			(4,074	)		(1,621	)
Income/(loss) before tax		4,164			(8,793	)		(12,327	)		(9,455	)
Income tax expense		-			-			-			-
Income/(loss) for the period		4,164			(8,793	)		(12,327	)		(9,455	)
Net income/(loss) per share (EPS):
Basic		0.07			(0.15	)		(0.22	)		(0.17	)
Diluted		0.07			(0.15	)		(0.22	)		(0.17	)
Weighted-average number of shares used to compute EPS:
Basic		57,266,088			57,164,145			57,048,187			56,855,987
Diluted		58,396,586			57,164,145			57,048,187			56,855,987

General information (Details)	Dec. 31, 2018 Platform
General information [Abstract]
Number of proprietary technology platforms	2

Basis of preparation (Details) SFr in Thousands			3 Months Ended		12 Months Ended
Basis of preparation (Details) SFr in Thousands	Sep. 22, 2016 CHF (SFr)	Sep. 22, 2016 USD ($)	Sep. 30, 2018 CHF (SFr)	Sep. 30, 2018 USD ($)	Dec. 31, 2018 CHF (SFr) Offering	Dec. 31, 2018 USD ($) Offering	Dec. 31, 2017 CHF (SFr)	Dec. 31, 2016 CHF (SFr)	Dec. 31, 2015 CHF (SFr)
Going concern [Abstract]
Company's cash position					SFr 156,462		SFr 124,377	SFr 152,210	SFr 76,522
Short-term financial assets					SFr 30,000		SFr 0
Number of public offerings \| Offering					3	3
Gross proceeds received \| $						$ 117,500,000
Public Offering [Member]
Going concern [Abstract]
Gross proceeds received	SFr 74,500	$ 75,900,000	SFr 116,300	$ 117,500,000	SFr 116,300	$ 117,500,000

Summary of significant accounting policies (Details) SFr in Millions	1 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2018 CHF (SFr) Segment
Income taxes [Abstract]
Tax loss carryforward period		7 years
Segment reporting [Abstract]
Number of operating segments \| Segment		1
Number of reportable segments \| Segment		1
Accounting pronouncements - not yet adopted [Abstract]
Lease liabilities		SFr 0.8
IFRS 16 [Member]
Accounting pronouncements - not yet adopted [Abstract]
Right-of-use assets		2.2
Lease liabilities		2.2
Cumulative effect adjustment to opening balance of accumulated losses		SFr 0.0
Preferred Shares [Member]
Preferred Shares [Abstract]
Conversion ratio of preferred shares to common shares	1
IT Equipment [Member]
Residual value over its estimated useful life [Abstract]
Useful lives or depreciation rates, property, plant and equipment		3 years
Laboratory Equipment [Member]
Residual value over its estimated useful life [Abstract]
Useful lives or depreciation rates, property, plant and equipment		5 years
Leasehold Improvements / Furniture [Member]
Residual value over its estimated useful life [Abstract]
Useful lives or depreciation rates, property, plant and equipment		5 years

Property, plant and equipment (Details) - CHF (SFr) SFr in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, plant and equipment [Abstract]
Property, plant and equipment, beginning of period	SFr 2,353	SFr 1,120
Property, plant and equipment, end of period	3,324	2,353	SFr 1,120
Acquisition Cost [Member]
Property, plant and equipment [Abstract]
Property, plant and equipment, beginning of period	5,087	3,274
Acquisitions	1,932	1,813
Disposals	(151)
Property, plant and equipment, end of period	6,868	5,087	3,274
Accumulated Depreciation [Member]
Property, plant and equipment [Abstract]
Property, plant and equipment, beginning of period	(2,734)	(2,154)
Disposals	151
Depreciation expense	(961)	(580)	(278)
Property, plant and equipment, end of period	(3,544)	(2,734)	(2,154)
Furniture [Member]
Property, plant and equipment [Abstract]
Property, plant and equipment, beginning of period	26	36
Property, plant and equipment, end of period	49	26	36
Furniture [Member] \| Acquisition Cost [Member]
Property, plant and equipment [Abstract]
Property, plant and equipment, beginning of period	85	81
Acquisitions	41	4
Disposals	0
Property, plant and equipment, end of period	126	85	81
Furniture [Member] \| Accumulated Depreciation [Member]
Property, plant and equipment [Abstract]
Property, plant and equipment, beginning of period	(59)	(45)
Disposals	0
Depreciation expense	(18)	(14)
Property, plant and equipment, end of period	(77)	(59)	(45)
Computers / IT [Member]
Property, plant and equipment [Abstract]
Property, plant and equipment, beginning of period	310	126
Property, plant and equipment, end of period	570	310	126
Computers / IT [Member] \| Acquisition Cost [Member]
Property, plant and equipment [Abstract]
Property, plant and equipment, beginning of period	569	298
Acquisitions	456	271
Disposals	0
Property, plant and equipment, end of period	1,025	569	298
Computers / IT [Member] \| Accumulated Depreciation [Member]
Property, plant and equipment [Abstract]
Property, plant and equipment, beginning of period	(259)	(172)
Disposals	0
Depreciation expense	(196)	(87)
Property, plant and equipment, end of period	(455)	(259)	(172)
Lab Equipment [Member]
Property, plant and equipment [Abstract]
Property, plant and equipment, beginning of period	1,850	934
Property, plant and equipment, end of period	2,510	1,850	934
Lab Equipment [Member] \| Acquisition Cost [Member]
Property, plant and equipment [Abstract]
Property, plant and equipment, beginning of period	4,161	2,792
Acquisitions	1,357	1,369
Disposals	(151)
Property, plant and equipment, end of period	5,367	4,161	2,792
Lab Equipment [Member] \| Accumulated Depreciation [Member]
Property, plant and equipment [Abstract]
Property, plant and equipment, beginning of period	(2,311)	(1,858)
Disposals	151
Depreciation expense	(697)	(453)
Property, plant and equipment, end of period	(2,857)	(2,311)	(1,858)
Leasehold Improvements [Member]
Property, plant and equipment [Abstract]
Property, plant and equipment, beginning of period	167	24
Property, plant and equipment, end of period	195	167	24
Leasehold Improvements [Member] \| Acquisition Cost [Member]
Property, plant and equipment [Abstract]
Property, plant and equipment, beginning of period	272	103
Acquisitions	78	169
Disposals	0
Property, plant and equipment, end of period	350	272	103
Leasehold Improvements [Member] \| Accumulated Depreciation [Member]
Property, plant and equipment [Abstract]
Property, plant and equipment, beginning of period	(105)	(79)
Disposals	0
Depreciation expense	(50)	(26)
Property, plant and equipment, end of period	SFr (155)	SFr (105)	SFr (79)

Cash and cash equivalents and financial assets, Cash and cash equivalents and short-term financial assets (Details) - CHF (SFr) SFr in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash and cash equivalents and financial assets [Abstract]
Cash and cash equivalents	SFr 156,462	SFr 124,377	SFr 152,210	SFr 76,522
Short-term financial assets due in one year or less	SFr 30,000	SFr 0

Cash and cash equivalents and financial assets, Cash and cash equivalents (Details) SFr in Thousands	12 Months Ended
	Dec. 31, 2018 CHF (SFr) $ / SFr € / SFr Deposit	Dec. 31, 2017 CHF (SFr) $ / SFr € / SFr	Dec. 31, 2016 CHF (SFr)	Dec. 31, 2015 CHF (SFr)
Cash and cash equivalents [Abstract]
Cash and cash equivalents	SFr 156,462	SFr 124,377	SFr 152,210	SFr 76,522
Number of deposits in escrow accounts \| Deposit	2
Deposits in escrow accounts	SFr 304	126
CHF [Member]
Cash and cash equivalents [Abstract]
Cash and cash equivalents	126,218	103,272
EUR [Member]
Cash and cash equivalents [Abstract]
Cash and cash equivalents	SFr 11,471	SFr 3,658
Translation rate into CHF \| € / SFr	1.125	1.169
USD [Member]
Cash and cash equivalents [Abstract]
Cash and cash equivalents	SFr 18,773	SFr 17,447
Translation rate into CHF \| $ / SFr	0.983	0.976

Prepaid expenses and accrued income (Details) - CHF (SFr) SFr in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Prepaid Expenses and Accrued Income [Line Items]
Prepaid expenses	SFr 2,364	SFr 1,440
Accrued income	3,667	2,799	SFr 889
Total	6,031	SFr 4,239
Biogen [Member]
Prepaid Expenses and Accrued Income [Line Items]
Accrued income	SFr 1,200
Percentage of accrued income	33.50%
Janssen [Member]
Prepaid Expenses and Accrued Income [Line Items]
Accrued income	SFr 2,100
Percentage of accrued income	56.80%

Other current receivables (Details) - CHF (SFr) SFr in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Other current receivables [abstract]
Other receivables	SFr 17	SFr 691
Swiss VAT	209	112
Withholding tax	10	115
Total	SFr 236	SFr 918
Top of Range [Member]
Other current receivables [abstract]
Maturity period of assets	3 months

Share capital (Details) - CHF (SFr) SFr / shares in Units, SFr in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Capital structure [Abstract]
Balance, beginning of period	SFr 116,839	SFr 142,380
Balance, end of period	SFr 177,623	SFr 116,839
Common Shares [Member]
Capital structure [Abstract]
Balance, beginning of period (in shares)	57,355,188	56,773,392
Issuance of shares - incentive plans (in shares)	207,145	581,796
Issuance of shares - Public Offering (net of transaction costs) (in shares)	10,000,000
Balance, end of period (in shares)	67,562,333	57,355,188
Nominal value per share (in CHF per share)	SFr 0.02
Share Capital [Member]
Capital structure [Abstract]
Balance, beginning of period	SFr 1,147	SFr 1,135
Issuance of Shares - Incentive Plans	4	12
Issuance of Shares - Public Offering (net of transaction costs)	200
Balance, end of period	1,351	1,147
Share Premium [Member]
Capital structure [Abstract]
Balance, beginning of period	188,299	188,166
Issuance of Shares - Incentive Plans	537	133
Issuance of Shares - Public Offering (net of transaction costs)	109,313
Balance, end of period	SFr 298,149	SFr 188,299

Share capital, Preferred Shares (Details) SFr / shares in Units, $ / shares in Units, SFr in Millions, $ in Millions		1 Months Ended	12 Months Ended
	Apr. 15, 2016 CHF (SFr) SFr / shares shares	Sep. 30, 2016	Dec. 31, 2018	Dec. 31, 2015 USD ($) Class CapitalIncrease Vote	Apr. 15, 2016 USD ($) $ / shares
Preferred Shares [Member]
Preferred Shares [Abstract]
Number of preferred shares classes outstanding \| Class				5
Conversion ratio of perferred shares to common shares		1
Number of separate capital increases \| CapitalIncrease				5
Percentage of shares outstanding owned by Preferred shareholders				80.10%
Term of equity financing			13 years
Number of votes entitled for each preferred share \| Vote				1
Dividends paid \| $				$ 0.0
Private placement shares issued (in shares) \| shares	1,401,792
Preferred Shares Series E [Member]
Preferred Shares [Abstract]
Nominal value per share (in CHF per share) \| SFr / shares	SFr 0.02
Private placement share price (in dollars per share) \| (per share)	SFr 9.42				$ 9.64
Subscription amount	SFr 13.2				$ 13.5

Share capital, Initial Public Offering and Follow-On Offerings (Details) $ / shares in Units, SFr in Thousands							3 Months Ended		12 Months Ended
	Jul. 31, 2018 CHF (SFr) shares	Jul. 31, 2018 USD ($) shares	Jul. 24, 2018 CHF (SFr) shares	Jul. 24, 2018 USD ($) $ / shares shares	Sep. 22, 2016 CHF (SFr) shares	Sep. 22, 2016 USD ($) $ / shares shares	Sep. 30, 2018 CHF (SFr)	Sep. 30, 2018 USD ($)	Dec. 31, 2018 CHF (SFr) Offering	Dec. 31, 2018 USD ($) Offering	Dec. 31, 2017 CHF (SFr)	Dec. 31, 2016 CHF (SFr)
Initial Public Offering (IPO) and Follow-On Offerings [Abstract]
Shares issued (in shares)					900,000	900,000
Gross proceeds received \| $										$ 117,500,000
Proceeds from public offerings of common shares, net of underwriting fees \| SFr									SFr 111,529		SFr 0	SFr 69,388
Net underwriting fees and transaction costs \| SFr									2,015			SFr 5,017
Initial Public Offering [Member]
Initial Public Offering (IPO) and Follow-On Offerings [Abstract]
Shares issued (in shares)					6,000,000	6,000,000
Share price (in dollars per share) \| $ / shares						$ 11.00
Gross proceeds received					SFr 74,500	$ 75,900,000	SFr 116,300	$ 117,500,000	SFr 116,300	$ 117,500,000
Proceeds from public offerings of common shares, net of underwriting fees					69,300	$ 70,600,000
Number of offerings \| Offering									3	3
Increase in share premium \| SFr					SFr 64,200
Net underwriting fees and transaction costs \| SFr									SFr 6,800
Net proceeds \| SFr									SFr 109,500
Over-Allotment [Member]
Initial Public Offering (IPO) and Follow-On Offerings [Abstract]
Shares issued (in shares)			1,108,695	1,108,695
Common Shares [Member]
Initial Public Offering (IPO) and Follow-On Offerings [Abstract]
Shares issued (in shares)					6,900,000	6,900,000
First Subscription Rights [Member]
Initial Public Offering (IPO) and Follow-On Offerings [Abstract]
Shares issued (in shares)			8,500,000	8,500,000
Share price (in dollars per share) \| $ / shares				$ 11.75
Gross proceeds received			SFr 98,900	$ 99,900,000
Second Subscription Rights [Member]
Initial Public Offering (IPO) and Follow-On Offerings [Abstract]
Shares issued (in shares)	1,500,000	1,500,000
Gross proceeds received	SFr 17,400	$ 17,600,000

Share capital, Shelf Registration Statement (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	May 04, 2018
Shelf Registration Statement [Abstract]
Shares authorized under Shelf Registration Statement (in shares)		350,000,000
Gross proceeds received	$ 117,500,000
Top of Range [Member]
Shelf Registration Statement [Abstract]
Additional proceeds from Shelf Registration Statement	$ 232,500,000

Trade payables, accrued liabilities and deferred income (Details) - CHF (SFr) SFr in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Trade payables, accrued liabilities and deferred income [Abstract]
Trade and other payables	SFr 1,979	SFr 1,092
Accrued research and development costs	6,803	5,430
Accrued payroll expenses	2,482	2,420
Other accrued expenses	1,135	457
Deferred income	351	355	SFr 521
Total current liabilities	12,750	9,754
Accrual of performance-related remuneration	1,800	1,100
Deferred income [Abstract]
Deferred income	351	355	SFr 521
Biogen [Member]
Trade payables, accrued liabilities and deferred income [Abstract]
Deferred income	400	400
Deferred income [Abstract]
Deferred income	SFr 400	SFr 400

Debt obligation (Details) SFr in Thousands, $ in Thousands	12 Months Ended
Debt obligation (Details) SFr in Thousands, $ in Thousands	Dec. 31, 2018 CHF (SFr) Installment	Dec. 31, 2018 USD ($)	Dec. 31, 2017 CHF (SFr)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Debt obligation [Abstract]
Gain on extinguishment of debt \| SFr	SFr 100
Finance receivable	199	$ 200	SFr 0
Short-term debt obligation	332	334	0
Long-term debt obligation	SFr 186	187	SFr 494	$ 500
Grants, LuMind Research Down Syndrome Foundation [Member]
Debt obligation [Abstract]
Funding commitment \| $		$ 200		$ 200	$ 200
Reimbursement percentage of funding commitment	125.00%
Number of installments \| Installment	3
Percentage of additional interest on total repayment	25.00%

Revenues, Changes in Contract Assets and Liabilities (Details) - CHF (SFr) SFr in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Revenues [Abstract]
Accrued income, beginning balance	SFr 2,799	SFr 889
Accrued income, additions	5,846	3,813
Accrued income, deductions	(4,978)	(1,903)
Accrued income, ending balance	3,667	2,799
Deferred income, beginning balance	355	521
Deferred revenue, additions	1,533	1,250
Deferred revenue, deductions	(1,537)	(1,416)
Deferred income, ending balance	SFr 351	SFr 355

Revenues, Recognized Revenues (Details) - CHF (SFr) SFr in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Revenues [Abstract]
Amounts included in the contract liability at the beginning of the period	SFr 1,551	SFr 1,401

Revenues, Contract Revenue Attributable to Licensing Arrangements (Details) - CHF (SFr) SFr in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Contract Revenue [Abstract]
Total contract revenue	SFr 1,403	SFr 2,305	SFr 2,028	SFr 1,458	SFr 16,422	SFr 1,074	SFr 753	SFr 2,006	SFr 7,194	SFr 20,255	SFr 23,214
Genentech [Member]
Contract Revenue [Abstract]
Total contract revenue									0	SFr 14,000	SFr 14,001
Percentage of contract revenues										69.00%	60.00%
Janssen [Member]
Contract Revenue [Abstract]
Total contract revenue									SFr 2,157	SFr 1,239	SFr 6,628
Percentage of contract revenues									30.00%		29.00%
Life Molecular Imaging [Member]
Contract Revenue [Abstract]
Total contract revenue									SFr 0	1,080	SFr 7
Biogen [Member]
Contract Revenue [Abstract]
Total contract revenue									SFr 4,024	SFr 3,930	2,100
Percentage of contract revenues									56.00%	19.00%
Other [Member]
Contract Revenue [Abstract]
Total contract revenue									SFr 1,013	SFr 6	SFr 478

Revenues, Anti-Abeta Antibody in AD - 2006 Agreement with Genentech (Details) SFr in Thousands, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018 CHF (SFr)	Sep. 30, 2018 CHF (SFr)	Jun. 30, 2018 CHF (SFr)	Mar. 31, 2018 CHF (SFr)	Dec. 31, 2017 CHF (SFr)	Sep. 30, 2017 CHF (SFr)	Jun. 30, 2017 CHF (SFr)	Mar. 31, 2017 CHF (SFr)	Dec. 31, 2018 CHF (SFr) Payment	Dec. 31, 2018 USD ($) Payment	Dec. 31, 2017 CHF (SFr)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 CHF (SFr)	Dec. 31, 2016 USD ($)	Dec. 31, 2018 USD ($)	Mar. 31, 2017 USD ($)
Revenues [Abstract]
Recognized revenues \| SFr	SFr 1,403	SFr 2,305	SFr 2,028	SFr 1,458	SFr 16,422	SFr 1,074	SFr 753	SFr 2,006	SFr 7,194		SFr 20,255		SFr 23,214
Anti-Abeta Antibody in AD [Member] \| 2006 Agreement with Genentech [Member]
Revenues [Abstract]
Period to provide notice of termination of agreement									3 months	3 months
Cumulative payments received	70,100								SFr 70,100						$ 65
Milestone payment recognized									31,600	$ 25
Milestone payment received									SFr 38,200	$ 40
Up-front consideration received								SFr 31,600								$ 25
Number of milestone payments received \| Payment									3	3
Recognized revenues \| $										$ 0		$ 0		$ 0
Anti-Abeta Antibody in AD [Member] \| 2006 Agreement with Genentech [Member] \| Bottom of Range [Member]
Revenues [Abstract]
Total potential collaboration agreement value	339,000								SFr 339,000						340
Total potential collaboration agreement value remaining	SFr 274,000								SFr 274,000						$ 275

Revenues, Anti-Tau Antibody in AD - 2012 Agreement with Genentech (Details) SFr in Thousands	1 Months Ended	3 Months Ended									12 Months Ended
	Jul. 31, 2016 CHF (SFr)	Dec. 31, 2018 CHF (SFr)	Sep. 30, 2018 CHF (SFr)	Jun. 30, 2018 CHF (SFr)	Mar. 31, 2018 CHF (SFr)	Dec. 31, 2017 CHF (SFr)	Sep. 30, 2017 CHF (SFr)	Jun. 30, 2017 CHF (SFr)	Mar. 31, 2017 CHF (SFr)	Jun. 30, 2016 CHF (SFr)	Dec. 31, 2018 CHF (SFr) Payment Program	Dec. 31, 2017 CHF (SFr)	Dec. 31, 2016 CHF (SFr)	Dec. 31, 2015 CHF (SFr)	Jun. 30, 2012 CHF (SFr)
Revenues [Abstract]
Recognized revenues		SFr 1,403	SFr 2,305	SFr 2,028	SFr 1,458	SFr 16,422	SFr 1,074	SFr 753	SFr 2,006		SFr 7,194	SFr 20,255	SFr 23,214
2012 Agreement with Genentech [Member]
Revenues [Abstract]
Recognized revenues											SFr 0	14,000	14,001
Anti-tau Antibody in AD [Member] \| 2012 Agreement with Genentech [Member]
Revenues [Abstract]
Number of additional indications \| Program											2
Period to provide notice of termination of agreement											90 days
Cumulative payments received		59,000									SFr 59,000
Milestone payment recognized										SFr 14,000
Milestone payment received	SFr 14,000					SFr 14,000					SFr 42,000			SFr 14,000
Up-front consideration received															SFr 17,000
Number of milestone payments received \| Payment											3
Recognized revenues											SFr 0	SFr 14,000	SFr 14,000
Anti-tau Antibody in AD [Member] \| 2012 Agreement with Genentech [Member] \| Bottom of Range [Member]
Revenues [Abstract]
Total potential collaboration agreement value															SFr 400,000
Total potential collaboration agreement value remaining		SFr 368,500									SFr 368,500

Revenues, Tau Vaccine in AD - 2014 Agreement with Janssen Pharmaceuticals (Details) - CHF (SFr) SFr in Thousands	1 Months Ended	3 Months Ended								12 Months Ended
	May 31, 2016	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2014
Revenues [Abstract]
Recognized revenues		SFr 1,403	SFr 2,305	SFr 2,028	SFr 1,458	SFr 16,422	SFr 1,074	SFr 753	SFr 2,006	SFr 7,194	SFr 20,255	SFr 23,214
2014 Agreement with Janssen Pharmaceuticals [Member]
Revenues [Abstract]
Recognized revenues										SFr 2,157	1,239	6,628
Tau Vaccine in AD [Member] \| 2014 Agreement with Janssen Pharmaceuticals [Member]
Revenues [Abstract]
Period to provide notice of termination of agreement										90 days
Cumulative payments received													SFr 25,900
Milestone payment received	SFr 4,900
Up-front consideration received													25,900
Recognized revenues										SFr 2,200	SFr 1,200	SFr 6,600
Tau Vaccine in AD [Member] \| 2014 Agreement with Janssen Pharmaceuticals [Member] \| Bottom of Range [Member]
Revenues [Abstract]
Total potential collaboration agreement value													SFr 500,000
Total potential collaboration agreement value remaining		SFr 458,000								SFr 458,000

Revenues, Tau-PET imaging agent in AD -2014 Agreement with Life Molecular Imaging (formerly Piramal Imaging SA) (Details) € in Thousands, SFr in Thousands	3 Months Ended									12 Months Ended
	Dec. 31, 2018 CHF (SFr)	Sep. 30, 2018 CHF (SFr)	Jun. 30, 2018 CHF (SFr)	Mar. 31, 2018 CHF (SFr)	Dec. 31, 2017 CHF (SFr)	Sep. 30, 2017 CHF (SFr)	Jun. 30, 2017 CHF (SFr)	Mar. 31, 2017 CHF (SFr)	Mar. 31, 2017 EUR (€)	Dec. 31, 2018 CHF (SFr)	Dec. 31, 2017 CHF (SFr)	Dec. 31, 2016 CHF (SFr)	Dec. 31, 2018 EUR (€)	Dec. 31, 2015 CHF (SFr)	Dec. 31, 2015 EUR (€)	May 31, 2014 CHF (SFr)	May 31, 2014 EUR (€)
Revenues [Abstract]
Recognized revenues	SFr 1,403	SFr 2,305	SFr 2,028	SFr 1,458	SFr 16,422	SFr 1,074	SFr 753	SFr 2,006		SFr 7,194	SFr 20,255	SFr 23,214
2014 Agreement with Life Molecular Imaging (formerly Piramal Imaging SA) Imaging [Member]
Revenues [Abstract]
Recognized revenues										SFr 0	1,080	7
Tau-PET Imaging Agent in AD [Member] \| 2014 Agreement with Life Molecular Imaging (formerly Piramal Imaging SA) Imaging [Member]
Revenues [Abstract]
Period to provide notice of termination of agreement										3 months
Cumulative payments received														SFr 664	€ 500
Milestone payment recognized								SFr 1,100	€ 1,000
Collaboration contract receivable for clinical milestones	7,000									SFr 7,000			€ 6,000
Collaboration contract receivable for regulatory, commercialization and sales milestones	SFr 171,000									171,000			€ 150,000
Recognized revenues										SFr 0	SFr 1,100	SFr 700
Tau-PET Imaging Agent in AD [Member] \| 2014 Agreement with Life Molecular Imaging (formerly Piramal Imaging SA) Imaging [Member] \| Top of Range [Member]
Revenues [Abstract]
Total potential collaboration agreement value																SFr 179,000	€ 157,000

Revenues, Alpha-synuclein and TDP-43 PET Tracers in AD - 2016 Agreement with Biogen (Details) SFr in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018 CHF (SFr)	Sep. 30, 2018 CHF (SFr)	Jun. 30, 2018 CHF (SFr)	Mar. 31, 2018 CHF (SFr)	Dec. 31, 2017 CHF (SFr)	Sep. 30, 2017 CHF (SFr)	Jun. 30, 2017 CHF (SFr)	Mar. 31, 2017 CHF (SFr)	Dec. 31, 2018 CHF (SFr) Obligation	Dec. 31, 2017 CHF (SFr)	Dec. 31, 2016 CHF (SFr)
Revenues [Abstract]
Recognized revenues	SFr 1,403	SFr 2,305	SFr 2,028	SFr 1,458	SFr 16,422	SFr 1,074	SFr 753	SFr 2,006	SFr 7,194	SFr 20,255	SFr 23,214
2016 Agreement with Biogen [Member]
Revenues [Abstract]
Recognized revenues									SFr 4,024	3,930	2,100
Alpha-synuclein and TDP-43 PET Tracer in AD [Member] \| 2016 Agreement with Biogen [Member]
Revenues [Abstract]
Number of performance obligations identified \| Obligation									2
Recognized revenues									SFr 4,000	SFr 3,900	SFr 2,100
Revenue recognition amortization period									12 months

Revenues, Recombinant Protein Therapeutic Candidate -2017 Agreement with Essex Bio-Technology Limited (Details) - CHF (SFr) SFr in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues [Abstract]
Recognized revenues	SFr 1,403	SFr 2,305	SFr 2,028	SFr 1,458	SFr 16,422	SFr 1,074	SFr 753	SFr 2,006	SFr 7,194	SFr 20,255	SFr 23,214
Recombinant Protein Therapeutic Candidate [Member] \| 2017 agreement, Essex Bio-Technology Limited [Member]
Revenues [Abstract]
Period to provide notice of termination of agreement									60 days
Period for initial contract									5 years
Period for initial research plan									2 years
Recognized revenues									SFr 700	SFr 100	SFr 0
Total potential collaboration agreement value remaining	SFr 800								SFr 800

Revenues, 2015 Grant from the Michael J. Fox Foundation (Details) SFr in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018 CHF (SFr)	Sep. 30, 2018 CHF (SFr)	Jun. 30, 2018 CHF (SFr)	Mar. 31, 2018 CHF (SFr)	Dec. 31, 2017 CHF (SFr)	Sep. 30, 2017 CHF (SFr)	Jun. 30, 2017 CHF (SFr)	Mar. 31, 2017 CHF (SFr)	Dec. 31, 2018 CHF (SFr) Obligation Milestone	Dec. 31, 2017 CHF (SFr)	Dec. 31, 2016 CHF (SFr)
Revenues [Abstract]
Recognized revenues	SFr 1,403	SFr 2,305	SFr 2,028	SFr 1,458	SFr 16,422	SFr 1,074	SFr 753	SFr 2,006	SFr 7,194	SFr 20,255	SFr 23,214
Grant from Michael J. Fox Foundation [Member]
Revenues [Abstract]
Number of milestones to achieve \| Milestone									4
Period of performance and development									12 months
Number of performance obligations identified \| Obligation									1
Total potential collaboration agreement value	SFr 380								SFr 380
Recognized revenues									300	SFr 100	SFr 0
FIH Study in H1 2019 [Member] \| Grant from Michael J. Fox Foundation [Member]
Revenues [Abstract]
Recognized revenues									SFr 0

Expenses by category (Details) - CHF (SFr) SFr in Thousands	3 Months Ended								12 Months Ended
Expenses by category (Details) - CHF (SFr) SFr in Thousands	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Research and Development [Abstract]
Operating expenses									SFr 32,921	SFr 23,822	SFr 18,767
Payroll expenses									10,662	8,552	6,450
Share-based compensation									694	289	557
Total research and development expenses	SFr 12,129	SFr 11,546	SFr 10,533	SFr 10,069	SFr 10,176	SFr 8,195	SFr 6,838	SFr 7,454	44,277	32,663	25,774
General and Administration [Abstract]
Operating expenses									4,903	3,857	3,168
Payroll expenses									5,740	4,984	3,969
Share-based compensation									1,824	1,290	759
Total general and administrative expenses	3,761	2,930	3,065	2,711	3,058	2,519	2,168	2,386	12,467	10,131	7,896
Financial Result, net [Abstract]
Interest income/ (expense)									(269)	184	36
Foreign currency remeasurement gain/(loss), net									(1,194)	(4,049)	3,443
Other finance income/(expense)									62	(7)	(119)
Finance result, net	SFr (191)	SFr (1,345)	SFr 427	SFr (292)	SFr 976	SFr 847	SFr (4,074)	SFr (1,621)	SFr (1,401)	SFr (3,872)	SFr 3,360

Related-party transactions (Details) SFr in Thousands		12 Months Ended
Related-party transactions (Details) SFr in Thousands	Jul. 31, 2018 shares	Dec. 31, 2018 CHF (SFr) Individual	Dec. 31, 2017 CHF (SFr)	Dec. 31, 2016 CHF (SFr)
Related-party transactions [Abstract]
Number of individuals, Board of Directors \| Individual		7
Number of individuals, Executive Management \| Individual		4
Short-term employee benefits		SFr 2,681	SFr 2,463	SFr 2,251
Post-employment benefits		160	166	154
Share-based compensation		1,683	1,267	832
Total		SFr 4,524	SFr 3,896	SFr 3,237
Number of shares purchased under subscription rights offering by related party (in shares) \| shares	614,147

Income taxes (Details) - CHF (SFr) SFr in Thousands	3 Months Ended								12 Months Ended
Income taxes (Details) - CHF (SFr) SFr in Thousands	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income taxes [Abstract]
Deferred tax assets	SFr 0				SFr 0				SFr 0	SFr 0	SFr 0
Deferred tax liabilities	0				0				0	0	0
Income tax expense reconciled to Income / (loss) [Abstract]
Loss before income tax									(50,951)	(26,411)	(7,096)
Tax benefit calculated at the statutory rate of 20.6% (20.5% for 2017 and 21% for 2016)									(10,507)	(5,420)	(1,504)
Permanent differences									334	40	(166)
Effect of unrecognized carry forward tax loss									0	0	0
Effect of unused tax losses and tax offsets not recognized as deferred tax assets									10,173	5,380	1,670
Effective income tax rate benefit / (expense)	SFr 0	SFr 0	SFr 0	SFr 0	SFr 0	SFr 0	SFr 0	SFr 0	SFr 0	SFr 0	SFr 0
Corporate tax rate									20.60%	20.50%	21.00%

Income taxes, Unrecognized Deductible Temporary Differences, Unused Tax Losses and Unused Tax Credits (Details) - CHF (SFr) SFr in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Unrecognized deductible temporary differences, unused tax losses and unused tax credits [Abstract]
Unrecognized deductible temporary differences, unused tax losses and unused tax credits	SFr 0	SFr 0	SFr 0
Unused tax losses and tax credits	114,959	67,501	40,505
Tax losses split by expiry date [Abstract]
Unused tax losses	109,294	62,575	36,707
Increase in tax losses available as an offset	48,900
Loss Expiry, December 31, 2018 [Member]
Tax losses split by expiry date [Abstract]
Unused tax losses	0	2,175	2,175
Loss Expiry, December 31, 2019 [Member]
Tax losses split by expiry date [Abstract]
Unused tax losses	16,566	16,566	16,566
Loss Expiry, December 31, 2020 [Member]
Tax losses split by expiry date [Abstract]
Unused tax losses	10,338	10,338	10,338
Loss Expiry, December 31, 2021 [Member]
Tax losses split by expiry date [Abstract]
Unused tax losses	0	0	0
Loss Expiry, December 31, 2022 [Member]
Tax losses split by expiry date [Abstract]
Unused tax losses	0	0	0
Loss Expiry, December 31, 2023 [Member]
Tax losses split by expiry date [Abstract]
Unused tax losses	7,628	7,628	7,628
Loss Expiry, December 31, 2024 [Member]
Tax losses split by expiry date [Abstract]
Unused tax losses	25,868	25,868	0
Loss Expiry, December 31, 2025 [Member]
Tax losses split by expiry date [Abstract]
Unused tax losses	48,894	0	0
Tax Losses [Member]
Unrecognized deductible temporary differences, unused tax losses and unused tax credits [Abstract]
Unrecognized deductible temporary differences, unused tax losses and unused tax credits	109,294	62,575	36,707
Deductible Temporary Differences Related to the Retirement Benefit Plan [Member]
Unrecognized deductible temporary differences, unused tax losses and unused tax credits [Abstract]
Unrecognized deductible temporary differences, unused tax losses and unused tax credits	SFr 5,665	SFr 4,926	SFr 3,798

Retirement benefit plan (Details) - CHF (SFr) SFr in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Obligation [Member]
Defined benefit pension plan amount recognized in balance sheet [Abstract]
Defined benefit obligation	SFr (17,942)	SFr (14,278)	SFr (11,596)
Fair value of plan assets	12,277	9,352	7,798
Total liability	(5,665)	(4,926)	(3,798)
Defined Benefit Plan [Member]
Net pension cost in statement of income [Abstract]
Service cost	1,095	912	742
Interest cost	100	81	75
Interest income	(65)	(55)	(56)
Net pension cost	1,130	938	761
Defined Benefit Plan [Member] \| Defined Benefit Obligation [Member]
Net pension cost in statement of income [Abstract]
Service cost	1,095	912	742
Interest cost	SFr 100	SFr 81	SFr 75
Employee [Member]
Disclosure of net defined benefit liability (asset) [line items]
Contributions paid to the plan by computing percentage in salary	47.00%
Employer [Member]
Disclosure of net defined benefit liability (asset) [line items]
Contributions paid to the plan by computing percentage in salary	53.00%

Retirement benefit plan, Changes in Defined Benefit Obligation (Details) - Defined Benefit Plan [Member] - CHF (SFr) SFr in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Changes in defined benefit obligation [Abstract]
Defined benefit obligation, beginning of period	SFr (4,926)	SFr (3,798)	SFr (2,787)
Service cost	(1,095)	(912)	(742)
Interest cost	(100)	(81)	(75)
Defined benefit obligation, end of period	(5,665)	(4,926)	(3,798)
Defined Benefit Obligation [Member]
Changes in defined benefit obligation [Abstract]
Defined benefit obligation, beginning of period	(14,278)	(11,596)	(9,439)
Service cost	(1,095)	(912)	(742)
Interest cost	(100)	(81)	(75)
Change in demographic assumptions	0	0	(389)
Change in financial assumptions	750	0	(26)
Change in experience assumptions	(888)	(735)	(378)
Benefit payments	(1,710)	(426)	(111)
Employees' contributions	(621)	(528)	(436)
Defined benefit obligation, end of period	SFr (17,942)	SFr (14,278)	SFr (11,596)

Retirement benefit plan, Changes in Fair Value of Plan Assets (Details) - Defined Benefit Plan [Member] - CHF (SFr) SFr in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Changes in fair value of plan assets [Abstract]
Interest income	SFr 65	SFr 55	SFr 56
Employer's contributions	693	590	511
Fair Value of Plan Assets [Member]
Changes in fair value of plan assets [Abstract]
Fair value of plan assets, beginning of period	9,352	7,798	6,652
Interest income	65	55	56
Employees' contributions	621	528	436
Employer's contributions	693	590	511
Benefits payments	1,710	426	111
Plan assets gains/(losses)	(164)	(45)	32
Fair value of plan assets, end of period	12,277	SFr 9,352	SFr 7,798
Expected contribution by employer to be paid to post-retirement benefit plans	SFr 788

Retirement benefit plan, Change in Net Defined Benefit Liability (Details) - Defined Benefit Plan [Member] - CHF (SFr) SFr in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Change in net defined benefit liability [Abstract]
Net defined benefit liabilities, beginning of period	SFr 4,926	SFr 3,798	SFr 2,787
Net pension cost through statement of income	1,130	938	761
Re-measurement through other comprehensive loss	302	780	761
Employer's contribution	(693)	(590)	(511)
Net defined benefit liabilities, end of period	SFr 5,665	SFr 4,926	SFr 3,798

Retirement benefit plan, Change in Other Comprehensive Loss (Details) - Defined Benefit Plan [Member] SFr in Thousands	12 Months Ended
	Dec. 31, 2018 CHF (SFr) yr	Dec. 31, 2017 CHF (SFr) yr	Dec. 31, 2016 CHF (SFr)
Change in other comprehensive loss [Abstract]
Weighted average duration period for defined benefit obligation \| yr	20.5	20.5
Change in Other Comprehensive Loss [Member]
Change in other comprehensive loss [Abstract]
Other comprehensive loss, beginning of period	SFr (3,981)	SFr (3,201)	SFr (2,440)
Effect of changes in demographic assumptions	0	0	(389)
Effect of changes in financial assumptions	750	0	(26)
Effect of changes in experience assumptions	(888)	(735)	(378)
Plan assets gains/(losses)	(164)	(45)	32
Other comprehensive loss, end of period	SFr (4,283)	SFr (3,981)	SFr (3,201)

Retirement benefit plan, Actuarial Assumptions and Sensitivity Analysis (Details) - Defined Benefit Plan [Member] - CHF (SFr) SFr in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Actuarial assumptions [Abstract]
Discount rate	0.90%	0.70%	0.70%
Rate of future increase in compensations	1.50%	1.50%	1.50%
Rate of future increase in current pensions	0.50%	0.50%	0.50%
Mortality and disability rates	BVG 2015G	BVG 2015G	BVG 2015G
Sensitivity analysis [Abstract]
Defined benefit obligation	SFr 5,665	SFr 4,926	SFr 3,798	SFr 2,787
+0.5% Increase [Member]
Sensitivity analysis [Abstract]
Percentage increase in actuarial assumption	0.50%
-0.5% Decrease [Member]
Sensitivity analysis [Abstract]
Percentage decrease in actuarial assumption	0.50%
Discount Rate [Member] \| +0.5% Increase [Member]
Sensitivity analysis [Abstract]
Defined benefit obligation	SFr 16,250
Impact on the net defined benefit obligation	1,692
Discount Rate [Member] \| -0.5% Decrease [Member]
Sensitivity analysis [Abstract]
Defined benefit obligation	19,906
Impact on the net defined benefit obligation	(1,964)
Future Salary Increase [Member] \| +0.5% Increase [Member]
Sensitivity analysis [Abstract]
Defined benefit obligation	18,475
Impact on the net defined benefit obligation	(533)
Future Salary Increase [Member] \| -0.5% Decrease [Member]
Sensitivity analysis [Abstract]
Defined benefit obligation	17,441
Impact on the net defined benefit obligation	501
Future Pension Cost [Member] \| +0.5% Increase [Member]
Sensitivity analysis [Abstract]
Defined benefit obligation	18,826
Impact on the net defined benefit obligation	(884)
Future Pension Cost [Member] \| -0.5% Decrease [Member]
Sensitivity analysis [Abstract]
Defined benefit obligation	17,346
Impact on the net defined benefit obligation	SFr 596

Share-based compensation, Plans Outstanding (Details)	12 Months Ended
Share-based compensation, Plans Outstanding (Details)	Dec. 31, 2018 shares Plan	Dec. 31, 2017 shares	Dec. 31, 2016 shares
Share-based compensation [Abstract]
Number of equity-based instrument plans \| Plan	4
Share-based plans outstanding [Abstract]
Number of options awarded (in shares)	484,403	276,766	285,250
Stock Option Plan A [Member]
Share-based plans outstanding [Abstract]
Number of options awarded (in shares)	362,750
Contractual life of options	15 years 6 months
Stock Option Plan B [Member]
Share-based plans outstanding [Abstract]
Number of options awarded (in shares)	819,000
Contractual life of options	10 years 6 months
Stock Option Plan C1 [Member]
Share-based plans outstanding [Abstract]
Number of options awarded (in shares)	6,775,250
Vesting conditions	4 years
Contractual life of options	10 years
2016 Share Option and Incentive Plan [Member] \| Executives and Directors [Member]
Share-based plans outstanding [Abstract]
Number of options awarded (in shares)	538,764
Vesting conditions	4 years
Contractual life of options	10 years
2016 Share Option and Incentive Plan [Member] \| Employees [Member]
Share-based plans outstanding [Abstract]
Number of options awarded (in shares)	222,405
Vesting conditions	4 years
Contractual life of options	10 years

Share-based compensation, Weighted Average Exercise Prices (Details)	12 Months Ended
	Dec. 31, 2018 CHF (SFr) shares yr	Dec. 31, 2018 USD ($) shares	Dec. 31, 2017 CHF (SFr) shares yr	Dec. 31, 2016 CHF (SFr) shares yr	Dec. 31, 2015 yr
Number of Options [Abstract]
Outstanding at beginning of period (in shares)	1,359,891	1,359,891	1,687,900	3,597,000
Forfeited during the year (in shares)	(73,624)	(73,624)	(1,750)	(106,000)
Cancelled during the year (in shares)			(31,250)	(19,250)
Exercised during the year (in shares)	(151,814)	(151,814)	(571,775)	(2,069,100)
Granted during the year (in shares)	484,403	484,403	276,766	285,250
Outstanding at end of period (in shares)	1,618,856	1,618,856	1,359,891	1,687,900
Exercisable (in shares)	932,175		900,474	1,284,525
Weighted Average Exercise Price [Abstract]
Outstanding at beginning of period (in CHF per share) \| SFr	SFr 2.09		SFr 0.15	SFr 0.15
Forfeited during the year (in CHF per share) \| SFr	9.16		0.15	0.15
Cancelled during the year (in CHF per share) \| SFr			0.15	0.15
Exercised during the year (in CHF per share) \| SFr	0.15		0.15	0.15
Granted during the year (in CHF per share)	9.79	$ 9.97	9.70	0.15
Outstanding at end of period (in CHF per share) \| SFr	4.25		2.09	0.15
Exercisable (in CHF per share) \| SFr	SFr 1.25		SFr 0.39	SFr 0.15
Weighted Average Remaining Term (Years) [Abstract]
Weighted average remaining term (years) \| yr	6.3		5.8	5.6	3.6
Exercisable \| yr	4.4		4.3	6.5

Share-based compensation, Outstanding Options, Range of Exercise prices and Expiration Dates (Details)	12 Months Ended
	Dec. 31, 2018 CHF (SFr) shares	Dec. 31, 2018 USD ($) shares	Dec. 31, 2017 CHF (SFr) shares	Dec. 31, 2017 USD ($) shares	Dec. 31, 2016 CHF (SFr) shares	Dec. 31, 2015 shares
Outstanding options, exercise price range and expiry dates [Abstract]
Outstanding Options (in shares)	1,618,856	1,618,856	1,359,891	1,359,891	1,687,900	3,597,000
Number of US denominated options granted (in shares)			18,850	18,850
Exercise price (in CHF/USD per share)			SFr 12.00	$ 12.30	SFr 0.15
Weighted average exercise price for options granted (in CHF/USD per share)	SFr 9.79	$ 9.97	9.70		SFr 0.15
Weighted average share price of common share options exercised (in dollars per share) \| $		9.92
Bottom of Range [Member]
Outstanding options, exercise price range and expiry dates [Abstract]
Exercise price (in CHF/USD per share)		8.33	9.53
Weighted average exercise price for options granted (in CHF/USD per share)	0.15	8.33
Top of Range [Member]
Outstanding options, exercise price range and expiry dates [Abstract]
Exercise price (in CHF/USD per share)		12.30	SFr 12.00
Weighted average exercise price for options granted (in CHF/USD per share)	SFr 9.53	$ 12.30
CHF 0.15 [Member]
Outstanding options, exercise price range and expiry dates [Abstract]
Outstanding Options (in shares)	924,166	924,166
CHF 0.15 [Member] \| Bottom of Range [Member]
Outstanding options, exercise price range and expiry dates [Abstract]
Expiration Dates	2020	2020
CHF 0.15 [Member] \| Top of Range [Member]
Outstanding options, exercise price range and expiry dates [Abstract]
Expiration Dates	2026	2026
CHF 9.53 [Member]
Outstanding options, exercise price range and expiry dates [Abstract]
Outstanding Options (in shares)	234,355	234,355
Expiration Dates	2027	2027
USD 8.33 to USD 12.30 [Member]
Outstanding options, exercise price range and expiry dates [Abstract]
Outstanding Options (in shares)	460,335	460,335
Expiration Dates	2028	2028

Share-based compensation, Weighted Average Grant date Fair Value and Assumptions (Details)	3 Months Ended	12 Months Ended
	Dec. 31, 2016 CHF (SFr) shares	Dec. 31, 2018 CHF (SFr) yr	Dec. 31, 2018 USD ($) yr	Dec. 31, 2017 CHF (SFr) yr	Dec. 31, 2017 USD ($) yr	Dec. 31, 2016 CHF (SFr) shares yr
Number and weighted average exercise prices of options under the share option programs [Abstract]
Weighted average fair value, options granted (in CHF/USD per share)		SFr 6.54	$ 6.66	SFr 7.29		SFr 5.85
Weighted average assumptions [Abstract]
Exercise price (in CHF/USD per share)				12.00	$ 12.30	0.15
Share Price, weighted average (in CHF/USD per share)			$ 9.87	SFr 8.77		SFr 5.96
Risk free interest rate		0.00%	0.00%	0.00%	0.00%	0.00%
Expected volatility		80.00%	80.00%	80.00%	80.00%	80.00%
Expected term \| yr		6	6	6	6	6
Dividend yield		0.00%	0.00%	0.00%	0.00%	0.00%
Share-based compensation [Abstract]
Expense charged against the income statement		SFr 2,518,000		SFr 1,579,000		SFr 1,317,000
Incremental fair value amount						SFr 238,000
Bottom of Range [Member]
Weighted average assumptions [Abstract]
Exercise price (in CHF/USD per share)			$ 8.33	9.53
Top of Range [Member]
Weighted average assumptions [Abstract]
Exercise price (in CHF/USD per share)			$ 12.30	SFr 12.00
Former Chief Financial Officer [Member]
Share-based compensation [Abstract]
Forfeited during the year (in shares) \| shares						98,500
Granted during the year (in shares) \| shares	49,250
Grant date fair value of the replacement award	SFr 674,000					SFr 674,000

Share-based compensation, Non-vested Share Awards (Details)	12 Months Ended
	Dec. 31, 2018 CHF (SFr) shares	Dec. 31, 2017 CHF (SFr) shares
Non-vested Share Awards [Member]
Share-based payment arrangement [Abstract]
Number of non-vested share awards granted (in shares)	69,371
Number of non-vested shares [Abstract]
Non-vested (in shares)	122,014
Forfeited during the year (in shares)	(25,673)
Granted during the year (in shares)	69,371
Vested during the year	(56,671)
Non-vested (in shares)	109,041	122,014
Vested and expected to vest (in shares)	64,012
Weighted Average grant date fair value [Abstract]
Non-vested (in CHF per share) \| SFr	SFr 9.59
Forfeited during the year (in CHF per share) \| SFr	9.48
Granted during the year (in CHF per share) \| SFr	9.43	SFr 9.62
Vested during the year (in CHF per share) \| SFr	9.60
Non-vested (in CHF per share) \| SFr	9.51	SFr 9.59
Vested and expected to vest (in CHF per share) \| SFr	SFr 9.65
Restricted Share Awards [Member]
Share-based payment arrangement [Abstract]
Number of non-vested share awards granted (in shares)	4,023
Vesting conditions	2 years 9 months
Contractual life of non-vested share awards	10 years
Number of non-vested shares [Abstract]
Granted during the year (in shares)	4,023
Restricted Stock Units [Member] \| Directors [Member]
Share-based payment arrangement [Abstract]
Number of non-vested share awards granted (in shares)	83,864
Vesting conditions	1 year
Contractual life of non-vested share awards	10 years
Number of non-vested shares [Abstract]
Granted during the year (in shares)	83,864
Restricted Stock Units [Member] \| Executives [Member]
Share-based payment arrangement [Abstract]
Number of non-vested share awards granted (in shares)	110,839
Vesting conditions	4 years
Contractual life of non-vested share awards	10 years
Number of non-vested shares [Abstract]
Granted during the year (in shares)	110,839

Commitments and contingencies (Details) - CHF (SFr) SFr in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Commitments and contingencies [Abstract]
External research projects	SFr 18,800
Notice period for cancellation of rental contract	12 months
Rent expense	SFr 800	SFr 500	SFr 400
Rental contracts amount	800
Commitments	33,074	12,372
Within One Year [Member]
Commitments and contingencies [Abstract]
Commitments	19,880	9,686
Between One and Three Years [Member]
Commitments and contingencies [Abstract]
Commitments	6,995	2,546
Between Three and Five Years [Member]
Commitments and contingencies [Abstract]
Commitments	5,009	140
More Than Five Years [Member]
Commitments and contingencies [Abstract]
Commitments	SFr 1,190	SFr 0

Earnings per share (Details) - CHF (SFr) SFr / shares in Units, SFr in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Earnings per share [Abstract]
Net income / (loss) attributable to owners of the Company	SFr (14,678)	SFr (13,516)	SFr (11,143)	SFr (11,614)	SFr 4,164	SFr (8,793)	SFr (12,327)	SFr (9,455)	SFr (50,951)	SFr (26,411)	SFr (7,096)
Earnings per share (EPS) [Abstract]
Basic and diluted, income / (loss) for the period attributable to equity holders (in CHF per share)	SFr (0.22)	SFr (0.21)	SFr (0.19)	SFr (0.20)					SFr (0.82)	SFr (0.46)	SFr (0.14)
Weighted-average number of shares used to compute EPS basic and diluted (in shares)	67,553,262	64,862,822	57,423,650	57,368,015	58,396,586	57,164,145	57,048,187	56,855,987	61,838,228	57,084,295	50,096,859
Antidilutive securities [Abstract]
Share options issued and outstanding (in-the-money) (in shares)									1,472,589	1,341,042	1,687,900
Restricted share awards subject to future vesting (in shares)									109,041	122,014	0
Total (in shares)									1,581,630	1,463,056	1,687,900

- Definition

The total of income less expenses from continuing and discontinued operations, excluding the components of other comprehensive income. [Refer: Other comprehensive income]

+ References

+ Details

Financial instruments and risk management (Details) SFr in Thousands	12 Months Ended
	Dec. 31, 2018 CHF (SFr) Institution	Dec. 31, 2017 CHF (SFr)	Dec. 31, 2016 CHF (SFr)
Financial assets and liabilities [Abstract]
Financial assets	SFr 187,002	SFr 125,421
Financial liabilities	12,917	9,893
Financial risks [Abstract]
Gain (loss) in finance income/(expense), net	(1,194)	(4,049)	SFr 3,443
Foreign Currency Exchange Risk [Member]
Financial risks [Abstract]
Gain (loss) in finance income/(expense), net	SFr (1,200)	(4,200)	SFr 3,400
Percentage exchange rate strengthened	10.00%
Percentage exchange rate weakened	10.00%
Net loss for period decrease, result of foreign exchange rate increase	SFr 3,000	2,100
Net loss for period increase, result of foreign exchange rate decrease	SFr 3,000	2,100
Credit Risk [Member]
Financial risks [Abstract]
Number of financial institutions holding cash and cash equivalents and short-term financial assets \| Institution	3
Liquidity Risk [Member]
Financial risks [Abstract]
Cash position rolling forecast period	18 months
Interest Rate [member]
Financial risks [Abstract]
Percentage of increase in interest rates	10.00%
Percentage of decrease in interest rates	10.00%
Interest Rate [member] \| Top of Range [Member]
Financial risks [Abstract]
Net loss for period increase, due to increase in interest rate	SFr 100
Net loss for period decrease, due to decrease in interest rate	100
Short-term Debt Obligation [Member]
Financial assets and liabilities [Abstract]
Financial liabilities	SFr 332	0
Short-term Debt Obligation [Member] \| Liquidity Risk [Member] \| Bottom of Range [Member]
Financial risks [Abstract]
Expected debt obligation payoff period	12 months
Long-Term Debt Obligation [Member]
Financial assets and liabilities [Abstract]
Financial liabilities	SFr 186	494
Long-Term Debt Obligation [Member] \| Liquidity Risk [Member] \| Bottom of Range [Member]
Financial risks [Abstract]
Expected debt obligation payoff period	12 months
Long-Term Debt Obligation [Member] \| Liquidity Risk [Member] \| Top of Range [Member]
Financial risks [Abstract]
Expected debt obligation payoff period	24 months
Trade and Other Payables [Member]
Financial assets and liabilities [Abstract]
Financial liabilities	SFr 1,979	1,092
Accrued Expenses [Member]
Financial assets and liabilities [Abstract]
Financial liabilities	10,420	8,307
Long-term Financial Assets [Member]
Financial assets and liabilities [Abstract]
Financial assets	304	126
Other Current Receivables [Member]
Financial assets and liabilities [Abstract]
Financial assets	236	918
Short-term Financial Assets [Member]
Financial assets and liabilities [Abstract]
Financial assets	30,000	0
Cash and Cash Equivalents [Member]
Financial assets and liabilities [Abstract]
Financial assets	SFr 156,462	SFr 124,377

Quarterly Financial Results (Unaudited) (Details) - CHF (SFr) SFr / shares in Units, SFr in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues [Abstract]
Contract revenue	SFr 1,403	SFr 2,305	SFr 2,028	SFr 1,458	SFr 16,422	SFr 1,074	SFr 753	SFr 2,006	SFr 7,194	SFr 20,255	SFr 23,214
Total revenue	1,403	2,305	2,028	1,458	16,422	1,074	753	2,006	7,194	20,255	23,214
Operating expenses [Abstract]
Research & development expenses	(12,129)	(11,546)	(10,533)	(10,069)	(10,176)	(8,195)	(6,838)	(7,454)	(44,277)	(32,663)	(25,774)
General & administrative expenses	(3,761)	(2,930)	(3,065)	(2,711)	(3,058)	(2,519)	(2,168)	(2,386)	(12,467)	(10,131)	(7,896)
Total operating expenses	(15,890)	(14,476)	(13,598)	(12,780)	(13,234)	(10,714)	(9,006)	(9,840)	(56,744)	(42,794)	(33,670)
Operating loss	(14,487)	(12,171)	(11,570)	(11,322)	3,188	(9,640)	(8,253)	(7,834)	(49,550)	(22,539)	(10,456)
Finance result, net	(191)	(1,345)	427	(292)	976	847	(4,074)	(1,621)	(1,401)	(3,872)	3,360
Loss before tax	(14,678)	(13,516)	(11,143)	(11,614)	4,164	(8,793)	(12,327)	(9,455)	(50,951)	(26,411)	(7,096)
Income tax expense	0	0	0	0	0	0	0	0	0	0	0
Loss for the period	SFr (14,678)	SFr (13,516)	SFr (11,143)	SFr (11,614)	SFr 4,164	SFr (8,793)	SFr (12,327)	SFr (9,455)	SFr (50,951)	SFr (26,411)	SFr (7,096)
Net income/(loss) per share (EPS) [Abstract]
Basic (in CHF per share)					SFr 0.07	SFr (0.15)	SFr (0.22)	SFr (0.17)
Diluted (in CHF per share)					SFr 0.07	SFr (0.15)	SFr (0.22)	SFr (0.17)
Basic and diluted (in CHF per share)	SFr (0.22)	SFr (0.21)	SFr (0.19)	SFr (0.20)					SFr (0.82)	SFr (0.46)	SFr (0.14)
Weighted-average number of shares used to compute EPS [Abstract]
Basic (in shares)					57,266,088	57,164,145	57,048,187	56,855,987
Diluted (in shares)	67,553,262	64,862,822	57,423,650	57,368,015	58,396,586	57,164,145	57,048,187	56,855,987	61,838,228	57,084,295	50,096,859
Basic and diluted (in shares)	67,553,262	64,862,822	57,423,650	57,368,015	58,396,586	57,164,145	57,048,187	56,855,987	61,838,228	57,084,295	50,096,859

Post balance sheet events (Details) $ / shares in Units, SFr in Thousands, shares in Millions, $ in Millions			12 Months Ended
	Jan. 23, 2019 CHF (SFr)	Jan. 23, 2019 USD ($) $ / shares shares	Dec. 31, 2018 CHF (SFr)	Dec. 31, 2017 CHF (SFr)	Dec. 31, 2016 CHF (SFr)	Feb. 28, 2019 CHF (SFr)
Post balance sheet events [Abstract]
Consideration received			SFr 198	SFr 200	SFr 0
Subsequent Event [Member] \| Convertible Note Agreement [Member]
Post balance sheet events [Abstract]
Consideration received	SFr 50,300	$ 50.0
Interest rate		0.75%
Conversion price (in dollars per share) \| $ / shares		$ 13.83
Number of shares issuable upon conversion (in shares) \| shares		3.6
Subsequent Event [Member] \| Collaboration Agreement with Lilly [Member]
Post balance sheet events [Abstract]
Up-front consideration received						SFr 80,000
Period to provide notice of termination of agreement	3 months	3 months