AC Immune (ACIU) 20-F 16 Mar 23 2022 FY Annual report (foreign) Financial data

Document and Entity Information

Document and Entity Information	12 Months Ended
	Dec. 31, 2022 shares
Entity Addresses [Line Items]
Document Type	20-F
Entity Registrant Name	AC IMMUNE SA
Document Registration Statement	false
Entity Central Index Key	0001651625
Document Period End Date	Dec. 31, 2022
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2022
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Annual Report	true
Document Transition Report	false
Document Shell Company Report	false
Entity File Number	001-37891
Entity Incorporation, State or Country Code	V8
Entity Address, Address Line One	EPFL INNOVATION PARK
Entity Address, Address Line Two	Building B
Entity Address, Postal Zip Code	1015
Entity Address, City or Town	Lausanne
Entity Address, Country	CH
Title of 12(b) Security	Common Shares, nominal value CHF 0.02 per share
Trading Symbol	ACIU
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding	83,620,364
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Document Accounting Standard	International Financial Reporting Standards
Entity Shell Company	false
Auditor Firm ID	1358
Auditor Name	PricewaterhouseCoopers SA
Auditor Location	Lausanne, Switzerland
Business Contact [Member]
Entity Addresses [Line Items]
Entity Address, Address Line One	EPFL INNOVATION PARK
Entity Address, Address Line Two	Building B
Entity Address, Postal Zip Code	1015
Entity Address, City or Town	Lausanne
Entity Address, Country	CH
Contact Personnel Name	Andrea Pfeifer
City Area Code	41
Local Phone Number	21 345 91 21

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - CHF (SFr) SFr in Thousands	Dec. 31, 2022	Dec. 31, 2021
Non-current assets
Property, plant and equipment	SFr 4,259	SFr 5,116
Right-of-use assets	2,808	2,914
Intangible asset	50,416	50,416
Long-term financial assets	361	363
Total non-current assets	57,844	58,809
Current assets
Prepaid expenses	4,708	3,015
Accrued income	408	975
Other current receivables	392	428
Short-term financial assets	91,000	116,000
Cash and cash equivalents	31,586	82,216
Total current assets	128,094	202,634
Total assets	185,938	261,443
Shareholders' equity
Share capital	1,797	1,794
Share premium	431,323	431,251
Treasury shares	(124)	(124)
Currency translation differences	10
Accumulated losses	(264,015)	(200,942)
Total shareholders' equity	168,991	231,979
Non-current liabilities
Long-term lease liabilities	2,253	2,340
Net employee defined benefit liabilities	3,213	7,098
Total non-current liabilities	5,466	9,438
Current liabilities
Trade and other payables	929	2,003
Accrued expenses	9,417	16,736
Deferred income	587	717
Short-term lease liabilities	548	570
Total current liabilities	11,481	20,026
Total liabilities	16,947	29,464
Total shareholders' equity and liabilities	SFr 185,938	SFr 261,443

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income/(Loss) - CHF (SFr) SFr in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Revenue
Contract revenue	SFr 3,935	SFr 0	SFr 15,431
Total revenue	3,935	0	15,431
Operating expenses
Research & development expenses	(60,336)	(62,282)	(59,487)
General & administrative expenses	(15,789)	(17,910)	(18,557)
Other operating income/(expense), net	1,343	1,182	1,353
Total operating expenses	(74,782)	(79,010)	(76,691)
Operating loss	(70,847)	(79,010)	(61,260)
Financial income	69	6,485	78
Financial expense	(355)	(581)	(184)
Exchange differences	393	113	(555)
Finance result, net	107	6,017	(661)
Loss before tax	(70,740)	(72,993)	(61,921)
Income tax expense	(13)	(3)	0
Loss for the period	SFr (70,753)	SFr (72,996)	SFr (61,921)
Loss per share:
Basic loss per share for the period attributable to equity holders	SFr (0.85)	SFr (0.97)	SFr (0.86)
Diluted loss per share for the period attributable to equity holders	SFr (0.85)	SFr (0.97)	SFr (0.86)

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income/(Loss) - CHF (SFr) SFr in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Condensed Consolidated Statements of Comprehensive Income/(Loss)
Loss for the period	SFr (70,753)	SFr (72,996)	SFr (61,921)
Items that may be reclassified to income or loss in subsequent periods (net of tax):
Currency translation differences	10	0	0
Items that will not to be reclassified to income or loss in subsequent periods (net of tax):
Remeasurement gains on defined-benefit plans (net of tax)	4,426	956	726
Other comprehensive income	4,436	956	726
Total comprehensive loss, net of tax	SFr (66,317)	SFr (72,040)	SFr (61,195)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Changes in Equity - CHF (SFr) SFr in Thousands	Share capital	Share premium	Treasury shares	Accumulated losses	Currency Translation Differences	Total
Balance, beginning of period at Dec. 31, 2019	SFr 1,437	SFr 346,526	SFr 0	SFr (75,521)	SFr 0	SFr 272,442
Net income/(loss) for the period	0	0	0	(61,921)	0	(61,921)
Other comprehensive income/(loss)	0	0	0	726	0	726
Total comprehensive loss, net of tax	0	0	0	(61,195)	0	(61,195)
Share-based payments	0	0	0	4,088	0	4,088
Common shares
Held as treasury shares	100	0	(100)	0	0	0
Restricted share awards	0	222	0	(222)	0	0
Exercise of options	1	142	0	0	0	143
Balance, end of period at Dec. 31, 2020	1,538	346,890	(100)	(132,850)	0	215,478
Net income/(loss) for the period	0	0	0	(72,996)	0	(72,996)
Other comprehensive income/(loss)	0	0	0	956	0	956
Total comprehensive loss, net of tax	0	0	0	(72,040)	0	(72,040)
Share-based payments	0	0	0	4,126	0	4,126
Proceeds from sale of treasury shares in public offerings, net of underwriting fees and transaction costs		12,097	24			12,121
Common shares
IPR&D asset purchase	130	49,741				49,871
Asset acquisition - common shares	12	4,587				4,599
Conversion note agreement	61	16,683				16,744
Held as treasury shares	48	0	(48)	0	0	0
Restricted share awards	1	171	0	(178)	0	(6)
Exercise of options	4	1,082	0	0	0	1,086
Balance, end of period at Dec. 31, 2021	1,794	431,251	(124)	(200,942)	0	231,979
Net income/(loss) for the period	0	0	0	(70,753)	0	(70,753)
Other comprehensive income/(loss)	0	0	0	4,426	10	4,436
Total comprehensive loss, net of tax	0	0	0	(66,327)	10	(66,317)
Share-based payments	0	0	0	3,330	0	3,330
Proceeds from sale of treasury shares in public offerings, net of underwriting fees and transaction costs		(8)	0			(8)
Common shares
Restricted share awards	0	76	0	(76)	0	0
Exercise of options	3	4	0	0	0	7
Balance, end of period at Dec. 31, 2022	SFr 1,797	SFr 431,323	SFr (124)	SFr (264,015)	SFr 10	SFr 168,991

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - CHF (SFr) SFr in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating activities
Loss for the period	SFr (70,753)	SFr (72,996)	SFr (61,921)
Adjustments to reconcile net loss for the period to net cash flows:
Depreciation of property, plant and equipment	1,793	1,897	1,535
Depreciation of right-of-use assets	566	509	432
Finance (income)/expense, net	(559)	(6,769)	376
Share-based compensation expense	3,330	4,126	4,088
Change in net employee defined benefit liability	541	590	705
Interest expense	355	573	175
(Gain)/loss on sale of fixed assets	0	13	(64)
Changes in working capital:
(Increase)/decrease in prepaid expenses	(1,718)	791	(1,304)
Decrease/(increase) in accrued income	567	594	(507)
Decrease/(increase) in other current receivables	36	(99)	(25)
(Decrease)/increase in accrued expenses	(6,114)	5,214	(757)
(Decrease)/increase in deferred income	(130)	425	(4,157)
(Decrease)/increase in trade and other payables	(1,073)	(84)	2,177
Cash used in operating activities	(73,159)	(65,216)	(59,247)
Interest received	69	0	78
Interest paid	(470)	(465)	(339)
Finance expenses paid	(8)	(8)	(9)
Net cash flows used in operating activities	(73,568)	(65,689)	(59,517)
Investing activities
Short-term financial assets, net	25,000	(51,000)	30,000
Purchases of property, plant and equipment	(1,239)	(2,635)	(1,706)
Proceeds from sale of property, plant and equipment	0	0	64
Rental deposits	2	(29)	(29)
Net cash flows provided by/(used in) investing activities	23,763	(53,664)	28,329
Financing activities
Proceeds from issuance of convertible loan	0	23,463	0
Transaction costs on issuance of shares	0	(6)	0
Proceeds from sale of treasury shares in public offerings, net of underwriting fees and transaction costs	(8)
Proceeds from issuance of treasury shares, net of underwriting fees and transaction costs	0	12,121	100
Proceeds from issuance of common shares - asset acquisition, net of transaction costs	0	4,599	0
Proceeds from issuance of common shares - option plan, net of transaction costs	7	1,082	143
Principal payments of lease obligations	(569)	(513)	(432)
Transaction costs associated with issuance of shares in relation to asset acquisition previously recorded in Accrued expenses	(776)
Repayment of short-term financing obligation	0	0	(514)
Payment for the issuance of treasury shares	0	0	(100)
Net cash flows (used in)/provided by financing activities	(1,346)	40,746	(803)
Net decrease in cash and cash equivalents	(51,151)	(78,607)	(31,991)
Cash and cash equivalents at beginning of period	82,216	160,893	193,587
Exchange gain on cash and cash equivalents	521	(70)	(703)
Cash and cash equivalents at end of the period	31,586	82,216	160,893
Supplemental non-cash activity
Capital expenditures in Trade and other payables or Accrued expenses	0	303	328
Issuance of shares for purchase of IPR&D asset in asset acquisition	0	50,416	0
Transaction costs associated with issuance of shares in relation to the asset acquisition recorded in Accrued expenses	0	776	0
Settlement of convertible notes recorded within Shareholders' equity	SFr 0	SFr 16,920	SFr 0

General information

General information	12 Months Ended
	Dec. 31, 2022
General information
General information	AC Immune SA Notes to the Consolidated Financial Statements (In CHF thousands except for share and per share data) ​ 1. AC Immune SA was founded in 2003. The Company controls a fully-owned subsidiary, AC Immune USA, Inc. (“AC Immune USA” or “Subsidiary” and, together with AC Immune SA, “AC Immune,” “ACIU,” “Company,” “we,” “our,” “ours,” “us”), which was registered and organized under the laws of Delaware, USA in June 2021. The Company and its Subsidiary form the Group. AC Immune SA is a clinical-stage biopharmaceutical company leveraging our two proprietary technology platforms to discover, design and develop novel proprietary medicines and diagnostics for prevention and treatment of neurodegenerative diseases (NDD) associated with protein misfolding. Misfolded proteins are generally recognized as the leading cause of NDD, such as Alzheimer’s disease (AD) and Parkinson’s disease (PD), with common mechanisms and drug targets, such as amyloid beta (Abeta), Tau, alpha-synuclein (a-syn) and TDP-43. Our corporate strategy is founded upon a three-pillar approach that targets (i) AD, (ii) focused non-AD NDD including Parkinson’s disease, ALS and NeuroOrphan indications and (iii) diagnostics. We use our two unique proprietary platform technologies, SupraAntigen (conformation-specific biologics) and Morphomer (conformation-specific small molecules), to discover, design and develop novel 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 transformed into a stock company. The Company’s corporate headquarters are located at EPFL Innovation Park Building B, 1015 Lausanne, Switzerland.

Basis of preparation

Basis of preparation	12 Months Ended
	Dec. 31, 2022
Basis of preparation and changes to the Company' accounting policies
Basis of preparation	2. Going concern The Company believes that it will be able to meet all of its obligations as they fall due for at least 12 months from the filing date of this Form 20-F, after considering the Company’s cash position of CHF 31.6 million and short-term financial assets of CHF 91.0 million as of December 31, 2022. Hence, these consolidated financial statements have been prepared on a going-concern basis. To date, the Company has financed its cash requirements primarily from its public offerings, share issuances, contract revenues from license and collaboration agreements (LCAs) and grants. 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 and our ability to raise additional capital as needed. These risks may require us to take certain measures such as delaying, reducing or eliminating certain programs. 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 pharmaceutical and biopharmaceutical industries, (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 consolidated financial statements have been prepared in accordance with International Financial Reporting Standards (IFRS) as issued by the International Accounting Standards Board (IASB). These consolidated financial statements were approved for issue by the Board of Directors on March 15, 2023. Basis of measurement The consolidated financial statements have been prepared under the historical cost convention except for items that are required to be accounted for at fair value.

Summary of significant accounti

Summary of significant accounting policies	12 Months Ended
	Dec. 31, 2022
Summary of significant accounting policies
Summary of significant accounting policies	3. The principal accounting policies adopted in the preparation of these consolidated financial statements are set out below. These policies have been consistently applied to all the years presented, unless otherwise stated. Functional and reporting currency These consolidated financial statements and accompanying notes are presented in Swiss Francs (CHF), which is AC Immune SA’s functional currency and the Group’s reporting currency. The Company’s subsidiary has a functional currency of the U.S. Dollar (USD). The respective functional currency represents the primary economic environment in which the entities operate. The following exchange rates have been used for the translation of the financial statements of AC Immune USA: ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, ​ ​ 2022 2021 2020 CHF/USD Closing rate, USD 1 0.933 0.923 N/A Weighted average exchange rate, USD 1 0.965 0.929 N/A ​ The results and financial position of AC Immune USA are translated into the presentation currency as follows: i. assets and liabilities for each balance sheet presented are translated at the closing rate at the date of that balance sheet; ii. income and expenses for each statement of income/(loss) are translated at average exchange rates; and iii. all resulting exchange differences are recognized in other comprehensive income/(loss), within cumulative translation differences. Basis of consolidation The annual closing date of the individual financial statements is December 31. The Company fully-owns its Subsidiary and fully consolidates its financial statements into these consolidated financial statements. All intercompany transactions have been eliminated. Foreign currency transactions Foreign currency transactions are translated into the respective functional currency using prevailing exchange rates at the dates of the transactions. Foreign exchange gains and losses resulting from the settlement of such transactions and from the translation at year-end exchange rates of monetary assets and liabilities denominated in foreign currencies are recognized in the consolidated statements of income/(loss). Any gains or losses from these translations are included in the consolidated statements of income/(loss) in the period in which they arise. Current vs. non-current classification The Company presents assets and liabilities in the consolidated balance sheets 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. Revenue recognition The Company applies IFRS 15 Revenue from Contracts with Customers The Company enters into LCAs which are within the scope of IFRS 15, under which it licenses certain rights to its product candidates and intellectual property to third parties. The terms of these arrangements typically include payment to the Company of one or more of the following: non-refundable, upfront 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 intellectual property. Each of these payments results in license, collaboration and other revenues, which are classified as contract revenue on the consolidated statements of income/(loss). 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, upfront 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, upfront 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 cumulative 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 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. 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 consolidated 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 1 year or less. For a complete discussion of accounting for contract revenue, see “Note 13. Contract revenues.” Research and development expenses Given the stage of development of the Company’s products, all research and development expenditure is expensed as incurred as it does not meet the capitalization criteria outlined in IAS 38 Intangible Assets ● 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 preclinical and clinical activities; ● employee-related expenses, including salaries and bonuses, benefits, travel and share-based compensation expenses; and ● all other allocated expenses such as facilities and information technology (IT) costs. For external research contracts, expenses include those associated with contract research organizations, or CROs, or contract manufacturing organizations, or CMOs. The invoicing from CROs or CMOs for services rendered do not always align with work performed. We accrue the cost of services rendered in connection with CRO or CMO activities based on our estimate of the “stage of completion” for such contracted services. We maintain regular communication with our CRO or CMO vendors to gauge the reasonableness of our estimates and accrue expenses as of the balance sheet date in the consolidated financial statements 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. General and administrative expenses General and administrative expenses are expensed as incurred and include personnel costs, expenses for outside professional services and all other allocated expenses. Personnel costs consist of salaries, cash bonuses, benefits and share-based compensation. Outside professional services consist of legal, accounting and audit services, IT and other consulting fees. Allocated expenses consist of certain IT, facilities and depreciation expenses. Grant income The Company has received grants, from time to time, from the Michael J. Fox Foundation (MJFF), the Target ALS Foundation (Target ALS) and other institutions to support certain research projects. Grants are recorded at their fair value in the consolidated statements of income/(loss) within other operating income/(expenses), net when there is reasonable assurance that the Company will satisfy the underlying grant conditions and the grants will be received. In certain circumstances, grant income may be recognized before formal grantor acknowledgement of milestone achievements. To the extent required, grant income is deferred and recognized on a systematic basis over the periods in which the Company expects to recognize the related expenses for which the grants are intended to compensate. Leases The Company applies IFRS 16 Leases Right-of-use assets and lease liabilities At inception of a leasing contract, the Company assesses whether a contract is, or contains, a lease based on whether the contract conveys the right to control the use of an identified asset for a period of time in exchange for consideration. The Company recognizes a right-of-use asset and a lease liability at the lease commencement date. The lease liability is initially measured at the present value of the lease payments that are not paid at the commencement date, discounted using the interest rate implicit in the lease or, if that rate cannot be readily determined, the Company’s incremental borrowing rate. The lease liabilities are classified as current or non-current based on the due dates of the underlying principal payments. Lease payments generally are fixed for the contract term. The lease liability is measured at amortized cost using the effective interest method. The lease liability is re-measured if there is a change in the estimated lease term, a change in future lease payments arising from a change in an index or rate, a change in the Company’s estimate of the amount expected to be payable under a residual value guarantee or a change in assessment of whether it will exercise a purchase, extension or termination option. At inception, the right-of-use asset comprises the initial lease liability and any initial direct costs. The right-of-use asset is depreciated over the shorter of the lease term or the useful life of the underlying asset. The right-of-use asset is periodically reduced by impairment losses, if any, and adjusted for certain re-measurements of the lease liability performed on as certain potential triggering events may arise (e.g. lease modifications). When the lease liability is re-measured, a corresponding adjustment is made to the carrying amount of the right-of-use asset or is recorded in profit or loss if the carrying amount of the right-of-use asset has been reduced to zero. The estimated lease term by right-of-use asset categories are as follows: ​ ​ ​ ​ ​ Buildings 5 years Office equipment ​ 5 years IT equipment ​ 5 years ​ Both the right-of-use-assets and lease liabilities are recognized in the consolidated balance sheets. 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 consolidated statements of income/(loss). Intangible assets AC Immune’s acquired in process research and development (IPR&D) asset is stated at cost less any impairments. The Company does not deem this asset ready for use until the asset obtains market approval. Therefore, during the development period after the date of acquisition until market approval, the IPR&D asset is not amortized. Upon market approval, the Company will determine the useful life of the asset, reclassify it from IPR&D and commence amortization. If the associated R&D effort is abandoned, the related IPR&D will likely be written off and we will record the relevant impairment charge. Finally, the Company will not capitalize future development costs in respect to this IPR&D asset until they meet the criteria for capitalization of research and development costs in accordance with IAS 38 Intangible Assets Our IPR&D asset is subject to impairment testing at least annually or when there are indications that the carrying value may not be recoverable until the completion of the development process. The determination of the recoverable amounts include key estimates which are highly sensitive to, and dependent upon, key assumptions. The Company uses a discounted cash flow method to determine the fair value less costs to sell (recoverable amount) of our IPR&D intangible asset. The Company starts with a forecast of all the expected net cash flows, which incorporates the consideration of a terminal value and then the Company applies a discount rate to arrive at a risk-adjusted net present value amount. Any impairment losses are recognized immediately in the consolidated statements of income/(loss). Fair value of financial assets and liabilities The Company’s financial assets and liabilities are composed of receivables, short-term financial assets, cash and cash equivalents, trade payables and lease liabilities. The fair value of these financial instruments approximates 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, unless otherwise explicitly noted. Receivables 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 through 12 months in duration. The Company assesses whether there is objective evidence that financial assets are impaired annually or whenever potential impairment triggers may occur. 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. Trade payables Trade payables are amounts due to third parties in the ordinary course of business. Share capital and public offerings Common shares are classified as equity. Share issuance costs are capitalized as incurred and will be shown in equity as a deduction, net of tax, from the proceeds received from existing or future offerings. Should a planned equity offering not be assessed as probable, the issuance costs would be expensed immediately in the consolidated statements of income/(loss). See “Note 11. Share capital.” Treasury shares Treasury shares are recognized at acquisition cost and deducted from shareholders’ equity at the time of acquisition, until they are subsequently resold, distributed or cancelled. Where such shares are subsequently sold, any consideration received is included in shareholders’ equity. See “Note 11. 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 and pension increases as well as discount rates of highly liquid corporate bonds that have terms to maturity approximating the terms of the related liability. To the extent that the fair value of the plan assets is greater than the present value of the defined benefit obligation as calculated by our independent actuary, the Company accounts for the effect of the asset ceiling test under IAS 19. Re-measurements of the net defined benefit liability, which comprise actuarial gains and losses and the return on plan assets (excluding interest) are recognized immediately in the consolidated statements of other comprehensive income/(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, considering any changes in the net defined benefit liability during the period as a result of contributions and benefit payments. Net interest expense/(income) and other expenses related to defined benefit plans are recognized in the consolidated statements of income/(loss). 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 consolidated statements of income/(loss), and a corresponding adjustment to equity over the remaining vesting period. Stock options granted under the Company’s stock option plans C1 and the 2016 Stock Option and Incentive Plan are valued using the Black-Scholes option-pricing model (see “Note 18. Share-based compensation”). 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 restricted share units using a reasonable estimate of market value of the common shares on the date of the award. We classify our share-based payments as equity-classified awards as they are settled in common shares. We measure equity-classified awards at their grant date fair value and do not subsequently re-measure 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 capital and 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 carry-forwards, 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. As disclosed in “Note 16. Income taxes,” 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. Earnings per share The Company presents basic earnings per share for each period in the consolidated financial statements. The earnings per share are calculated by dividing the earnings of the period by the weighted-average number of shares outstanding during the period. Diluted earnings per share reflect the potential dilution that could occur if dilutive securities such as share options or non-vested restricted share units 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 the dilutive earnings per share calculation. 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 LCAs, (ii) clinical development accruals, (iii) net employee defined benefit liability, (iv) income taxes, (v) share-based compensation, (vi) right-of-use assets and lease liabilities and (vii) our IPR&D asset. 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. Segment reporting The Company has one segment. The Company currently focuses most 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 operating segment. Non-current assets are located in, and revenue is allocated and recorded within, the Company’s country of domicile, Switzerland. Accounting policies, new standards, interpretations and amendments adopted by the Company There are no new IFRS standards, amendments or interpretations that are mandatory as of January 1, 2022 that are relevant to the Company. Additionally, the Company has not adopted any standard, interpretation or amendment that has been issued but is not yet effective. Such standards are not currently expected to have a material impact on the entity in the current or future reporting periods and on foreseeable future transactions.

Property, plant and equipment

Property, plant and equipment	12 Months Ended
	Dec. 31, 2022
Property, plant and equipment.
Property, plant and equipment	4. The following tables show the movements in the net book values of property, plant and equipment for the years ended December 31, 2022 and 2021, respectively: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2022 ​ ​ ​ IT Laboratory Leasehold Assets under ​ In CHF thousands ​ Furniture ​ equipment ​ equipment ​ improvements ​ construction ​ Total Acquisition cost: Balance at December 31, 2021 265 1,754 9,142 810 695 12,666 Additions 20 151 576 184 5 936 Transfers — 4 47 646 (697) — Balance at December 31, 2022 285 1,909 9,765 1,640 3 13,602 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accumulated depreciation: Balance at December 31, 2021 (106) (1,316) (5,739) (389) — (7,550) Depreciation expenses (53) (283) (1,278) (179) — (1,793) Balance at December 31, 2022 (159) (1,599) (7,017) (568) — (9,343) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Carrying amount: December 31, 2021 159 438 3,403 421 695 5,116 December 31, 2022 126 310 2,748 1,072 3 4,259 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2021 ​ ​ ​ IT Laboratory Leasehold ​ Assets under ​ In CHF thousands ​ Furniture ​ equipment ​ equipment ​ improvements construction ​ Total Acquisition cost: ​ Balance at December 31, 2020 214 1,497 7,681 464 ​ 277 10,133 Additions 51 250 1,268 346 ​ 695 2,610 Transfers ​ — ​ 7 ​ 270 ​ — ​ (277) ​ — Disposals — — (77) — ​ — (77) Balance at December 31, 2021 265 1,754 9,142 810 ​ 695 12,666 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accumulated depreciation: ​ Balance at December 31, 2020 (61) (970) (4,405) (281) ​ — (5,717) Depreciation expenses (45) (346) (1,398) (108) ​ — (1,897) Disposals — — 64 — ​ — 64 Balance at December 31, 2021 (106) (1,316) (5,739) (389) ​ — (7,550) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Carrying amount: ​ December 31, 2020 153 527 3,276 183 ​ 277 4,416 December 31, 2021 159 438 3,403 421 ​ 695 5,116 ​ AC Immune continues to enhance its laboratory equipment to support its R&D functions. This effort has continued for the year ended December 31, 2022, with CHF 0.8 million invested in lab equipment, including the expansion of our leased lab space, and IT equipment, representing an increase of 7%. For the years ended December 31, 2022, 2021 and 2020, the Company incurred CHF 1.8 million, CHF 1.9 million and CHF 1.5 million in depreciation expenses, respectively.

Right-of-use assets, long-term

Right-of-use assets, long-term financial assets and lease liabilities	12 Months Ended
	Dec. 31, 2022
Right-of-use assets, long-term financial assets and lease liabilities
Right-of-use assets, long-term financial assets and lease liabilities	5. The Company recognized additions and remeasurements of right-of-use of leased assets for buildings or for office equipment totaling CHF 0.5 million and CHF 1.2 million for the years ended December 31, 2022 and 2021, respectively. In 2022, these increases are predominantly associated with the remeasurement of our leased office space. Regarding lease liabilities, the amortization depends on the rate implicit in the contract or the incremental borrowing rate for the respective lease component. The weighted averages of the incremental borrowing rates as of December 31, 2022 are 3.5% (2.5% for 2021) for buildings, 5.3% (5.3% for 2021) for office equipment and 2.6% (2.6% for 2021) for IT equipment. The following tables show the movements in the net book values of right-of-use of leased assets for the years ended December 31, 2022 and 2021, respectively: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Office IT ​ In CHF thousands ​ Buildings ​ equipment ​ equipment ​ Total Balance as of December 31, 2021 2,776 98 40 2,914 Additions and remeasurements 460 — — 460 Depreciation (528) (24) (14) (566) Balance as of December 31, 2022 2,708 74 26 2,808 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Office IT ​ In CHF thousands ​ Buildings ​ equipment ​ equipment ​ Total Balance as of December 31, 2020 ​ 2,106 ​ 63 ​ 54 ​ 2,223 Additions and remeasurements 1,144 71 — 1,215 Dispositions ​ — ​ (15) ​ — ​ (15) Depreciation (474) (21) (14) (509) Balance as of December 31, 2021 2,776 98 40 2,914 ​ For the years ended December 31, 2022, and 2021, the impact on the Company’s consolidated statements of income/(loss) and consolidated statements of cash flows is detailed in the table below. ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, In CHF thousands ​ 2022 2021 Statements of income/(loss) ​ Depreciation of right-of-use assets ​ 566 509 Interest expense on lease liabilities ​ 68 63 Expense for short-term leases and leases of low value ​ 750 723 Total ​ 1,384 1,295 ​ ​ ​ ​ ​ Statements of cash flows ​ Total cash outflow for leases ​ 1,388 1,299 ​ The following table presents the contractual undiscounted cash flows for lease liabilities as of December 31, 2022 and 2021: ​ ​ ​ ​ ​ ​ ​ As of ​ ​ December 31, In CHF thousands ​ 2022 2021 Less than one year 638 638 1-3 years 1,230 1,260 3-5 years 1,187 1,203 Total 3,055 3,101 ​ The Company also has two deposits in escrow accounts totaling CHF 0.4 million for the lease of the Company’s premises as of December 31, 2022 and 2021, respectively.

Asset acquisition

Asset acquisition	12 Months Ended
	Dec. 31, 2022
Asset acquisition
Asset acquisition	6. In 2021, the Company closed its acquisition with Affiris AG (Affiris) for the program portfolio of therapeutics targeting a-syn, notably ACI-7104.056 (previously PD01), a clinically-validated active vaccine candidate for the treatment of Parkinson’s disease (the Transferred Assets). The Company acquired the Transferred Assets and USD 5.0 (CHF 4.6) million in cash in exchange for 7,106,840 shares of the Company at closing, for a total value of USD 58.7 (CHF 55.1) million. With the closing of this transaction, the Company recorded an IPR&D intangible asset associated with ACI-7104.056 for USD 53.7 (CHF 50.4) million. The Company used a risk-adjusted discounted cash flow method to determine the fair value of the intangible asset using a discount rate of 15%. See “Note 7. Intangible assets” for further details on assumptions used. As the Company transferred its own equity instruments in consideration for the asset transferred, the acquisition was assessed in accordance with IFRS 2 Share-based Payment The Company determined that the acquisition of the Transferred Assets did not qualify as a business combination in accordance with IFRS 3 Business Combinations The following table summarizes the amounts of the Transferred Assets acquired: ​ ​ ​ ​ In CHF thousands Cash 4,634 IPR&D asset 50,416 Total 55,050 ​

Intangible assets

Intangible assets	12 Months Ended
	Dec. 31, 2022
Intangible assets
Intangible assets	7. AC Immune’s acquired IPR&D asset is a clinically-validated active vaccine candidate for the treatment of Parkinson’s disease. The asset is not yet ready for use until the asset obtains market approval. The carrying amount and net book value are detailed below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2022 ​ As of December 31, 2021 ​ Gross ​ ​ Gross ​ ​ ​ ​ carrying ​ Accumulated ​ Net book ​ carrying ​ Accumulated ​ Net book In CHF thousands ​ amount ​ amortization ​ value ​ amount ​ amortization ​ value Acquired IPR&D asset ​ 50,416 — 50,416 50,416 — 50,416 Total intangible assets ​ 50,416 — 50,416 50,416 — 50,416 ​ In accordance with IAS 36 Impairment of Assets Fair Value Measurement The key assumptions used in the valuation model in accordance with an income approach to determine the recoverable amount include observable and unobservable key inputs as follows: ● Anticipated research and development costs; ● Anticipated costs of goods and sales and marketing expenditures; ● Probability of achieving clinical and regulatory development milestones in accordance with certain industry benchmarks; ● Target indication prevalence and incidence rates; ● Anticipated market share; ● General commercialization expectations such as anticipated pricing and uptake; ● Expected patent life and market exclusivity periods; and ● Other metrics such as the tax rate. The Company’s valuation model calculates the risk-adjusted, net cash flows through the projected period of market exclusivity across target sales regions. The Company uses a discount rate of 17% (15% for 2021), based on the assumed cost of capital for the Company over the forecast period. See “Note 6. Asset acquisition” for further details.

Cash and cash equivalents and s

Cash and cash equivalents and short-term financial assets	12 Months Ended
	Dec. 31, 2022
Cash and cash equivalents and financial assets
Cash and cash equivalents and short-term financial assets	8. The Company’s cash and cash equivalents are maintained in the following respective currencies as of December 31, 2022 and 2021: ​ ​ ​ ​ ​ ​ ​ As of ​ ​ December 31, In CHF thousands ​ 2022 2021 Cash and cash equivalents 31,586 82,216 Total 31,586 82,216 By currency CHF 24,418 64,941 EUR 1,313 2,253 USD 5,855 15,022 Total cash and cash equivalents 31,586 82,216 ​ As of December 31, 2022 and 2021, the Company’s funds were held in CHF, EUR and USD currencies. Funds held in EUR and USD were translated into CHF at a rate of 0.994 and 0.933 and 1.045 and 0.923, respectively, for each currency and year. The following table summarizes the Company’s short-term financial assets as of December 31, 2022 and 2021: ​ ​ ​ ​ ​ ​ ​ As of ​ ​ December 31, In CHF thousands ​ 2022 2021 Short-term financial assets due in one year or less 91,000 116,000 Total short-term financial assets 91,000 116,000 ​

Prepaid expenses and accrued in

Prepaid expenses and accrued income	12 Months Ended
	Dec. 31, 2022
Prepaid expenses and accrued income
Prepaid expenses and accrued income	9. ​ ​ ​ ​ ​ ​ ​ As of ​ ​ December 31, In CHF thousands ​ 2022 2021 Prepaid expenses 4,708 3,015 Accrued income 408 975 Total prepaid expenses and accrued income 5,116 3,990 ​ The Company’s prepaid expenses relate mainly to research contracts with down-payments at contract signature with the related activities to start or continue into 2023 as well as prepaid payroll-related expenses. Accrued income consists of CHF 0.4 million as of December 31, 2022 associated with our MJFF grants and Target ALS (see “Note 13.2. Grant income”). This amount represents 100% of our total accrued income as of December 31, 2022. As of December 31, 2021, the Company recorded CHF 0.9 million of accrued income associated with our MJJF grants. This amount represented 87% of our total accrued income as of December 31, 2021.

Other current receivables

Other current receivables	12 Months Ended
	Dec. 31, 2022
Other current receivables [Abstract]
Other current receivables	10. ​ ​ ​ ​ ​ ​ ​ As of ​ ​ December 31, In CHF thousands ​ 2022 2021 Other current receivable 124 101 Swiss VAT 249 327 Withholding tax 19 — Total other current receivables 392 428 ​ The maturity of these assets is less than 3 months

Share capital

Share capital	12 Months Ended
	Dec. 31, 2022
Share capital
Share capital	11. As of December 31, 2022 and 2021, the issued share capital amounted to CHF 1,796,675 and CHF 1,794,013, respectively, and is composed of outstanding common shares of 83,620,364 and 83,479,013, respectively, and treasury shares of 6,214,021 and 6,221,617, respectively. The table below summarizes the Company’s capital structure: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ In CHF thousands ​ Common Treasury Share Share Treasury ​ ​ shares ​ shares ​ capital ​ premium ​ shares December 31, 2020 76,936,738 (5,000,000) 1,538 346,890 (100) Proceeds from sale of treasury shares in public offerings, net of underwriting fees and transaction costs — 1,171,543 — 12,097 24 Asset purchase agreement, net of transaction costs 7,106,840 — 142 54,328 — Conversion of note agreements, net of transaction costs ​ 3,026,634 — 61 16,683 — Issuance of shares – incentive plans, net of transaction costs ​ 237,258 — 5 1,253 — Issuance of shares to be held as treasury shares, net of transaction costs 2,393,160 (2,393,160) 48 — (48) December 31, 2021 89,700,630 (6,221,617) 1,794 431,251 (124) Proceeds from sale of treasury shares in public offerings, net of underwriting fees and transaction costs — ​ 7,596 ​ — ​ (8) ​ 0 Issuance of shares – incentive plans, net of transaction costs 133,755 ​ — ​ 3 ​ 80 ​ — December 31, 2022 89,834,385 (6,214,021) 1,797 431,323 (124) ​ The common shares and treasury shares have nominal values of CHF 0.02 per share. All shares have been fully paid. These treasury shares held by the Company are not considered outstanding shares as of December 31, 2022 or 2021. Authorized capital The Company’s Board of Directors is authorized to increase the share capital, in one or several steps, until June 24, 2024, by a maximum amount of CHF 400,000 by issuing a maximum of 20,000,000 registered shares with a par value of CHF 0.02 each, to be fully paid up. An increase of the share capital (i) by means of an offering underwritten by a financial institution, a syndicate or another third party or third parties, followed by an offer to the then-existing shareholders of the Company and (ii) in partial amounts, shall also be permissible. Conditional share capital for bonds and similar debt instruments The Company’s share capital may be increased by a maximum aggregate amount of CHF 100,000 through the issuance of a maximum of 5,000,000 registered shares, payable in full, each with a nominal value of CHF 0.02 per share, through the exercise of conversion and/or option or warrant rights granted in connection with bonds or similar instruments, issued or to be issued by the Company or by subsidiaries of the Company, including convertible debt instruments. Conditional share capital for employee benefit plans The Company’s share capital may be increased by a maximum aggregate amount of CHF 96,000 through the issuance of not more than 4,800,000 common shares, payable in full, each with a nominal value of CHF 0.02 per share, by the exercise of options rights that have been granted to employees, consultants, members of the board of directors, or other person providing services to the Company or a subsidiary. Shelf registration statement On April 28, 2021, the Company filed a Shelf Registration Statement on Form F-3 (Reg. No. 333-255576) (the “Shelf Registration Statement”) with the SEC. The Shelf Registration Statement was declared effective by the SEC on May 5, 2021. The Shelf Registration Statement allows the Company to offer and sell, from time to time, up to USD 350,000,000 of common shares, 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. At the market equity offering In Q3 2020, AC Immune issued 5,000,000 common shares with a nominal value of CHF 0.02, which became treasury shares. The Company also established an “at the market offering program” (“ATM”) for the sale of up to USD 80.0 (CHF 74.6) million worth of our common shares issued from time to time by entering into an Open Market Sale Agreement (“Sales Agreement”) with Jefferies LLC (“Jefferies”) as the sales agent under a prior registration statement on Form F-3 which expired in Q2 2021. In Q2 2021, the Company filed a new registration statement on Form F-3 and an accompanying prospectus supplement in order to renew its ATM program. The Company also entered into a second Open Market Sale Agreement (the “new Sales Agreement”) with Jefferies to continue the ATM program. In Q3, 2021, the Company issued 2,393,160 common shares with a nominal value of CHF 0.02 to be held as treasury shares. Through December 31, 2022, the Company has sold 1,179,139 common shares previously held as treasury shares pursuant to the new Sales Agreement, raising USD 13.3 (CHF 12.1) million, net of underwriting fees and transaction costs. We have paid commissions to Jefferies totaling USD 0.4 (CHF 0.4) million through December 31, 2022, for share issuances in accordance with our ATM programs. For the years ended December 31, 2022, 2021 and 2020, the Company has expensed issuance costs of nil, nil and CHF 0.5 million, respectively, in the consolidated statements of income/(loss). Convertible note agreement Concurrently with the Asset Purchase Agreement, the Company entered into two separate Convertible Note Agreements with entities affiliated with each of Athos Service GmbH and First Capital Partner GmbH, both of which entities are shareholders of Affiris. Each Convertible Note Agreement provided for the sale of an unsecured subordinated Convertible Note of the Company with an aggregate principal amount of USD 12.5 (CHF 11.7) million for total net proceeds of USD 25 (CHF 23.5) million. In 2021, the affiliated entities exercised their options to convert their respective USD 12.5 (CHF 11.7) million notes. As a result of these conversions, 1,513,317 common

Trade and other payables and ac

Trade and other payables and accrued expenses	12 Months Ended
	Dec. 31, 2022
Accrued expenses
Trade and other payables and accrued expenses	12. ​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ December 31, In CHF thousands ​ 2022 ​ 2021 Trade and other payables 929 2,003 Total trade and other payables 929 2,003 ​ ​ ​ ​ ​ Accrued research and development costs 5,360 10,361 Accrued payroll expenses 2,898 3,562 Other accrued expenses 1,159 2,813 Total accrued expenses 9,417 16,736 ​ An accrual of CHF 2.1 million and CHF 2.3 million was recognized for performance-related remuneration within accrued payroll expenses for 2022 and 2021, respectively. In 2021, an accrual of CHF 3.7 million was recorded as part of our cost sharing arrangement with Janssen within accrued research and development costs and CHF 0.8 million was recorded as accrued stamp duty for the issuance of shares as part of the Company’s asset acquisition within other accrued expenses.

Contract revenues

Contract revenues	12 Months Ended
	Dec. 31, 2022
Contract revenues
Contract revenues	13. For the years ended December 31, 2022, 2021 and 2020, AC Immune generated contract revenues of CHF 3.9 million, nil and CHF 15.4 million, respectively. The following tables provide contract revenue amounts from its LCAs for the years ended December 31, 2022, 2021 and 2020, respectively. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, In CHF thousands 2022 2021 2020 Lilly — — 14,348 Janssen — — 1,083 Life Molecular Imaging 3,935 — — Total contract revenues 3,935 — 15,431 ​ LMI accounted for 100% of our contract revenues in 2022 and Lilly accounted for 93% of our contract revenues in 2020. During the years ended December 31, 2022, 2021 and 2020, the Company recognized the following contract revenues as a result of changes in the contract asset and the contract liability balances in the respective periods: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, In CHF thousands ​ 2022 ​ 2021 ​ 2020 Revenues recognized in the period from: Amounts included in the contract liability at the beginning of the period ​ — — 4,477 Performance obligations satisfied in previous periods 3,935 — 10,000 ​ 13.1 Morphomer Tau small molecule – 2018 license agreement with Eli Lilly and Company In December 2018, we entered into an exclusive, worldwide licensing agreement with Eli Lilly and Company (Lilly) to research and develop Morphomer Tau small molecules for the treatment of AD and other neurodegenerative diseases. More specifically, this is an exclusive license with the right to Lilly to grant sublicenses under the ACIU Patents, the ACIU know-how, and ACIU’s interests in the Joint Patents and the joint know-how to Exploit the Licensed Compounds and Licensed Products. The agreement became effective on January 23, 2019 (the “effective date”) when the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, expired. In Q3 2019, the Company and Lilly entered into the first amendment to divide the first discretionary milestone payment under the agreement of CHF 60 million into two installments, with the first CHF 30 million paid in Q3 2019 and the second CHF 30 million to be paid on or before March 31, 2020 unless Lilly terminated the agreement earlier. In Q1 2020, the Company and Lilly entered into a second amendment to replace the second CHF 30 million to be paid on or before March 31, 2020 with two milestone payments, one of CHF 10 million to be paid on or before March 31, 2020 and the other of CHF 60 million following the first patient dosed in a Phase 2 clinical study of a licensed product in the U.S. or EU. Per the terms of the agreement, the Company received an initial upfront payment of CHF 80 million in Q1 2019 for the rights granted by the Company to Lilly. To date, the Company has completed a Phase 1 clinical study with ACI-3024. Additionally, the Company and Lilly have continued candidate characterization across the research program, identifying new and highly differentiated candidates with desired cerebrospinal fluid exposure and selectivity for pathological aggregated Tau. These will be broadly developed in Tau-dependent neurodegenerative diseases by Lilly. Lilly is responsible for leading and funding further clinical development and will retain global commercialization rights for all indications. Per the terms of the agreement, the Company may become eligible to receive additional milestone payments totaling up to approximately CHF 880 million for clinical and regulatory milestones and CHF 900 million upon achievement of certain commercial milestones. In addition to milestones, we will be eligible to receive royalties on sales at a percentage rate ranging from the low double-digits to the mid-teens. The agreement will terminate by the date of expiration of the last royalty term for the last licensed product. However, under the terms of the agreement, Lilly may terminate the agreement at any time by providing 3 months AC Immune assessed this arrangement in accordance with IFRS 15 and concluded that Lilly is a customer. The Company identified the following significant performance obligations under the contract: (i) a right-of-use license and (ii) research and development activities outlined in the development plan. Per the agreement, the Company was responsible for the preclinical and Phase 1 activities for the first clinical candidate, ACI-3024, which the Company determined was distinct and capable of being completed by Lilly or a third party. Preclinical activities for which AC Immune was responsible prior to their completion in Q2 2019 included final manufacturing of materials for use in the regulatory submission of the protocol and in the Phase 1 study. For the completed Phase 1, AC Immune was responsible for leading the study design, obtaining relevant regulatory agency approvals, arranging necessary third-party contracts, completing patient selection, ensuring patient treatment, following up with patients, drafting the clinical study report development and other relevant clinical activities to ensure that the primary objective of the study was completed. The Company used CMOs for certain of its preclinical activities and CROs to complete certain Phase 1 activities and to issue the final clinical study report. The Company’s preclinical and Phase 1 activities did not represent integrated services with the licensed intellectual property for which Lilly contracted. Lilly purchased a license to the Company’s Tau therapeutic small-molecule program, which was delivered at commencement of the agreement, and AC Immune’s preclinical and Phase 1 activities did not affect the form or functionality of this license. The Company’s objective for the Phase 1 activity was to assess safety and tolerability and did not modify or customize ACI-3024. The completion of these preclinical and Phase 1 activities does not affect the licensed intellectual property. Finally, per the agreement, each party has three representatives on a joint steering committee (JSC). Depending upon the agenda, additional field experts can attend the JSC to provide the technical and scientific contribution required. The JSC meets on a regular basis depending on agreements between the representatives. The JSC is responsible for serving as the forum to (i) discuss, review and approve certain activities by reviewing and discussing the development progress with updates on back-up candidates, (ii) discuss, review and approve all amendments to the global development plan, (iii) periodically discuss and review commercialization of licensed products and (iv) review and approve reports related to development costs among other activities. The JSC is intended to ensure that communication between the parties remains consistent and that the development plan is progressing as intended. The valuation of each performance obligation involves estimates and assumptions with revenue recognition timing to be determined by either delivery or the provision of services. The Company used the residual approach to estimate the selling price for the right-of-use license and an expected cost plus margin approach for estimating the research and development activities. The right-of-use license was delivered on the effective date. The research and development activities were delivered over time as the services were performed. For these services, revenue was recognized over time using the input method, based on costs incurred to perform the services, as the level of costs incurred over time is thought to best reflect the transfer of services to Lilly. The Company determined the value of the research and development activities to be CHF 6.9 million and deferred this balance from the effective date. To date, the Company has cumulatively recognized CHF 6.9 million in contract revenue, resulting in no deferred income (contract liability) on the consolidated balance sheets. The remaining CHF 73.1 million from the upfront payment was allocated to the right-of-use license and recognized on the effective date. At inception of the agreement, none of the clinical, regulatory or commercial milestones had been included in the transaction price, as all milestone amounts were fully constrained. To date, the Company has recognized CHF 40 million from milestone payments triggered in Q3 2019 and Q1 2020 related to the right-of-use license for intellectual property as there were no further constraints related to these milestones. 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 Lilly 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, 2022, 2021 and 2020, we have recognized nil, nil and CHF 14.3 million, respectively, from this arrangement. Anti-Abeta antibody in AD – 2006 agreement with Genentech, a member of the Roche Group In November 2006, we signed an exclusive, worldwide licensing agreement for crenezumab, our humanized monoclonal therapeutic antibody targeting misfolded Abeta. The agreement was amended March 2009, January 2013, May 2014 and May 2015. The agreement also provides for the development of a second therapeutic product for a non- AD indication based on the same intellectual property and anti-Abeta antibody compound. The value of this partnership is potentially greater than USD 340 (CHF 317) 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 when that notice is given. Genentech commenced a first Phase 3 clinical study in March 2016 for crenezumab (CREAD). In March 2017, Genentech started a second Phase 3 clinical trial (CREAD 2). Since 2013, crenezumab has also been studied in a Phase 2 preventive trial in individuals who carry the PSEN1 E280A autosomal-dominant mutation and do not meet the criteria for mild cognitive impairment due to AD or dementia due to AD and are, thus, in a preclinical phase of AD (autosomal dominant AD (ADAD)). In 2019, Genentech initiated a Tau Positron Emission Tomography (PET) substudy to the ongoing Phase 2 trial in ADAD to evaluate the effect of crenezumab on Tau burden, which may also increase the understanding of disease progression in the preclinical stage of ADAD. 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 ranging from the mid-single digits to mid-teens. To date, we have received total milestone payments of USD 65 (CHF 70.1) million comprised of an upfront payment of USD 25 (CHF 31.6) million and of 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 3 months 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-of-use license and (ii) conducting 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 upfront consideration received of USD 25 (CHF 31.6) million. 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 256.4) 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. In January 2019, we announced that Roche, the parent of Genentech, is discontinuing the CREAD and CREAD 2 (BN29552 and BN29553) Phase 3 studies of crenezumab in people with prodromal-to-mild sporadic AD. The decision came after an interim analysis conducted by the Independent Data Monitoring Center (IDMC) indicated that crenezumab was unlikely to meet its primary endpoint of change from baseline in CDR-SB Score. This decision was not related to the 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. For the years ended December 31, 2022, 2021 and 2020, we have recognized no revenues from this arrangement. Anti-Tau antibody in AD – 2012 agreement with Genentech, a member of the Roche Group In June 2012, we entered into a second agreement with Genentech to research, develop and commercialize our anti-Tau antibodies for use as immunotherapeutics and diagnostics. The agreement was amended in December 2015. 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 low-double digits. The agreement also provides for collaboration on at least one additional therapeutic indication outside of AD built on the same anti-Tau antibody program as well an anti-Tau diagnostic product. 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 when that notice is given. To date, we have received payments totaling CHF 59 million, including a milestone payment of CHF 14 million received and recognized received 3 months 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-of-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 an upfront consideration received of CHF 17 million. 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. In September 2020, the Company reported that Genentech informed us of top line results from a Phase 2 trial of the anti-Tau antibody, semorinemab, in early (prodromal to mild) Alzheimer’s disease (AD) which show that semorinemab did not meet its primary efficacy endpoint of reducing decline on CDR-SB compared to placebo. The primary safety endpoint was however met. Two secondary endpoints, Alzheimer’s Disease Assessment Scale-Cognitive Subscale 13 (ADAS-Cog13) and Alzheimer’s Disease Cooperative Study Group – Activities of Daily Living Inventory (ADCS-ADL), were not met. In August 2021, the Company reported that Genentech had informed the Company that the Lauriet study had met one of its co-primary endpoints, ADAS-Cog 11. The second co-primary endpoint, ADCS-ADL, was not met. Safety data showed that semorinemab was well tolerated with an acceptable safety profile and no unanticipated safety signals. In November 2021, the Company reported that Genentech had presented the full top-line data from the Lauriet study during a late-breaking session at the 14 th For the years ended December 31, 2022, 2021 and 2020, we have recognized no revenues from this arrangement. Tau vaccine in AD – 2014 agreement with Janssen Pharmaceuticals, Inc. In December 2014, we entered into an agreement with Janssen Pharmaceuticals, Inc. (Janssen), part 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 collaboration is potentially up to CHF 500 million and includes upfront and clinical, regulatory and commercial milestones. In addition to milestones, we will be eligible to receive royalties on sales at a percentage rate ranging from the high-single digits to the mid-teens for the phospho-Tau vaccine program. In April 2016, July 2017, January 2019, November 2019 and December 2022, the companies entered into the first, second, third, fourth and fifth amendments, respectively. These amendments allow for the alignment of certain payment and activity provisions with the Development Plan and Research Plan activities. We and Janssen have completed the co-development of the second-generation lead therapeutic vaccines, ACI-35.030 and JACI- 35.054, through Phase 1b/2a. In November 2022, it was announced that ACI-35.030 was selected to advance into further development based on interim data from the ongoing Phase 1b/2a trial. AC Immune and Janssen will jointly share research and development costs until the completion of the first Phase 2b (AC Immune’s contribution to the first Phase 2b trial is capped). From Phase 2b and onwards, Janssen will assume responsibility for the clinical development, manufacturing and commercialization of ACI-35.030. Under the terms of the agreement, Janssen may terminate the agreement at any time after completion of the first Phase 1b clinical study in 2016 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 an upfront, non-refundable license fee of CHF 25.9 million, which we recognized as revenue in 2014. In May 2016, we received a payment of CHF 4.9 million for reaching a clinical milestone in the first 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-of-use license and (ii) research and development services including a development and chemistry, manufacturing and controls 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 of 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 upfront consideration received of CHF 25.9 million. 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 payment of CHF 4.9 million 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 digits to mid-teen royalties on aggregate net sales for the phospho-Tau vaccine program. 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, 2022, 2021 and 2020, we have recognized nil, nil and CHF 1.1 million, respectively, from this arrangement. Tau-PET imaging agent –2014 agreement with Life Molecular Imaging (LMI) (formerly Piramal Imaging SA) In May 2014 (as amended in June 2022), we entered into an agreement, our first diagnostic partnership, with LMI, the former Piramal Imaging SA. The partnership with LMI is an exclusive, worldwide licensing agreement for the research, development and commercialization of the Company’s Tau protein PET tracers supporting the early diagnosis and clinical management of AD and other Tau-related disorders and includes upfront and sales milestone payments totaling up to EUR 160 (CHF 159) million, plus royalties on sales at a percentage rate ranging from mid-single digits to low-teens. LMI may terminate the LCA at any time by providing 3 months’ notice to us. In connection with this agreement, AC Immune received a payment of EUR 500 (CHF 664) thousand, which was fully recognized in 2015. In Q1 2017, we recorded a milestone payment of EUR 1 (CHF 1.1) million related to the initiation of “Part B” of the first-in-man Phase 1 study. In Q3 2019, the Company recognized EUR 2 (CHF 2.2) million in connection with the initiation of a Phase 2 trial of Tau-PET tracer in patients with mild cognitive impairment and mild–to-moderate AD in comparison with non-demented control participants. In Q3 2022, the Company recognized EUR 4 (CHF 3.9) million linked to the progression of the Tau-PET tracer into late-stage development in AD. The Company is eligible to receive additional variable consideration related to the achievement of certain clinical milestones totaling EUR 4 (CHF 4) million should the compound make it through Phase 3 clinical studies. We are also eligible to receive potential regulatory and sales-based milestones totaling EUR 148 (CHF 138) million. Finally, the Company is eligible for royalties from the mid-single digits to low-teens. AC Immune assessed this arrangement in accordance with IFRS 15 and concluded that LMI is a customer. The Company has identified that the right-of-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 or commercial milestones has 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 LMI and therefore are recognized at the later of when the performance obligation is satisfied or the related sales occur. The Company considered LMI’s right to sublicense and develop the Tau protein PET tracers, and the fact that LMI 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. For the years ended December 31, 2022, 2021 and 2020, the Company has recognized CHF 3.9 million, nil and nil, respectively, from this arrangement. 13.2 Grants from the Michael J. Fox Foundation In May 2020, the Company, as part of a joint arrangement with Skåne University Hospital (Skåne) in Sweden, was awarded a USD 3.2 (CHF 3.0) million grant from the MJFF’s Ken Griffin Alpha-synuclein Imaging Competition. As part of this grant, AC Immune is eligible to receive USD 2.5 (CHF 2.3) million directly from the MJFF. Skåne will receive USD 0.7 (CHF 0.7) million of the total grant directly from the MJFF over two arrangement with Skåne in Sweden totaling USD 0.5 (CHF 0.5) million for the continued development of its alpha-synuclein PET imaging diagnostic agent. As part of this grant, AC Immune received USD 0.4 (CHF 0.4) million directly from the MJFF. Skåne will receive USD 0.1 (CHF 0.1) million of the total grant directly from the MJFF over the duration of the grant period. The MJFF expects that AC Immune and Skåne will complete tasks according to the agreed timelines. AC Immune’s funding is variable depending on the satisfactory achievement of these specific tasks within a specific period of time. In December 2021, the Company announced that it had been awarded two grants totaling USD 1.5 (CHF 1.4) million to advance small molecule PD programs. One award will support an existing early-stage program to develop small molecules that can prevent intracellular aggregation and spreading of a-syn. The other award will fund research on the therapeutic potential of chemically and mechanistically novel, brain penetrant small molecule inhibitors of NLRP3 inflammasome activation for the treatment of PD. For the years ended December 31, 2022, 2021 and 2020, the Company has recognized CHF 1.2 million, CHF 1.1 million and CHF 1.3 million, respectively, from its MJFF grants. As of December 31, 2022, the Company recorded CHF 0.3 million in accrued income and CHF 0.5 million in deferred income, respectively.

Expenses by category

Expenses by category	12 Months Ended
	Dec. 31, 2022
Expenses by category [Abstract]
Expenses by category	14. Research and development ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, In CHF thousands 2022 2021 2020 Operating expenses 41,166 44,289 43,787 Payroll expenses 17,548 16,465 14,424 Share-based compensation 1,622 1,528 1,276 Total research and development expenses 60,336 62,282 59,487 ​ For the years ended December 31, 2022, 2021 and 2020, the Company incurred CHF 60.3 million, CHF 62.3 million and CHF 59.5 million in research and development expenses, respectively. The decrease in 2022 is mainly driven by decreases in direct R&D expenditures across various programs. For the years ended December 31, 2022, 2021 and 2020, the Company had 122.4, 108.6 and 115.3 FTEs in our research and development functions. General and administrative ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, In CHF thousands 2022 2021 2020 Operating expenses 6,207 7,031 7,471 Payroll expenses 7,874 8,281 8,274 Share-based compensation 1,708 2,598 2,812 Total general and administrative expenses 15,789 17,910 18,557 ​ For the years ended December 31, 2022, 2021 and 2020, the Company incurred CHF 15.8 million, CHF 17.9 million and CHF 18.6 million in general and administrative expenses, respectively. The decrease in 2022 compared with the prior year predominantly relates to certain transaction costs associated with our prior year asset acquisition which did not repeat in 2022 as well as a reduction in headcount. For the years ended December 31, 2022, 2021 and 2020, the Company had 22.5, 27.3 and 26.7 FTEs in our general and administrative functions. Financial result, net ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, In CHF thousands 2022 2021 2020 Financial income 69 6,485 78 Financial expense (355) (581) (184) Exchange differences 393 113 (555) Finance result, net 107 6,017 (661) ​ Our finance result primarily consists of interest expense associated with our short-term financial assets and lease liabilities as well as foreign currency exchange differences. For the year ended December 31, 2022, the decrease in financial result, net related primarily to the prior year CHF 6.5 million gain on the conversion features related to the Company’s convertible notes due to certain Affiris affiliated entities that did not recur.

Related-party transactions

Related-party transactions	12 Months Ended
	Dec. 31, 2022
Related-party transactions [Abstract]
Related-party transactions	15. Board of directors and executive management compensation Key management includes the board of directors and executive management. For 2022, there were eight members (2021: eight and 2020: seven) of the Board (excluding the CEO) and seven members (2021: six and 2020: five) of executive management (including the CEO). Compensation was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, In CHF thousands ​ 2022 ​ 2021 ​ 2020 Short-term employee benefits 4,187 4,403 3,497 Post-employment benefits 295 266 214 Share-based compensation 2,503 2,997 2,578 Total compensation 6,985 7,666 6,289 ​

Income taxes

Income taxes	12 Months Ended
	Dec. 31, 2022
Income taxes [Abstract]
Income taxes	16. The Group recognized less than CHF 0.1 million, less than CHF 0.1 million and nil in income taxes and no deferred tax asset or liability The Group’s income tax expense for each year can be reconciled to loss before tax as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, In CHF thousands 2022 2021 2020 Loss before income tax (70,740) (72,993) (61,921) Tax benefit calculated at the domestic rates applicable in the respective countries (9,616) (9,930) (8,441) (Income not subject to tax)/expenses not deductible for tax purposes 455 (375) 462 Effect of unused tax losses and tax offsets not recognized as deferred tax assets 9,174 10,308 7,979 Effective income tax rate (benefit)/expense 13 3 — ​ The Swiss tax rate used for the 2022 reconciliations is the corporate tax rate of 13.6% (13.6% in 2021 and 2020, respectively) payable by corporate entities in the Canton of Vaud, Switzerland on taxable profits under tax law in that jurisdiction. The below table details the total unrecognized deductible temporary differences, unused tax losses and unused tax credits: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ December 31, In CHF thousands 2022 2021 2020 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 264,089 197,152 121,948 Deductible temporary differences related to: Right-of-use assets and lease liabilities, net — — — Retirement benefit plan 3,213 7,098 7,464 Total 267,302 204,250 129,412 ​ The following table details the tax losses carry forwards of the Company and their respective expiry dates: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ December 31, In CHF thousands ​ 2022 ​ 2021 ​ 2020 Tax losses split by expiry date: December 31, 2024 ​ 15,231 ​ 15,231 15,231 December 31, 2025 48,894 48,894 48,894 December 31, 2026 — — — December 31, 2027 57,824 57,824 57,824 December 31, 2028 75,204 75,204 — December 31, 2029 66,936 — — Total unrecorded tax loss carryforwards 264,089 197,153 121,949 ​ The tax losses available for future offset against taxable profits have increased by CHF 66.9 million from 2021, representing the amount of tax losses that are additionally available as an offset, 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 were not met at the balance sheet date.

Retirement benefit plan

Retirement benefit plan	12 Months Ended
	Dec. 31, 2022
Retirement benefit plan
Retirement benefit plan	17. 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 a board of trustees, which consists of an equal number of employer and employee representatives of its members. The board of trustees is responsible for the administration of the plan assets and for the definition of the investment strategy. 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. 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, as 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 in accordance with IAS 19. The following table sets forth the status of the defined benefit pension plan and the amount that is recognized in the consolidated balance sheets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ December 31, In CHF thousands ​ 2022 ​ 2021 ​ 2020 Defined benefit obligation (32,410) (33,889) (30,213) Fair value of plan assets 29,197 26,791 22,749 Total liability (3,213) (7,098) (7,464) ​ The following amounts have been recorded as net pension cost in the consolidated statements of income/(loss): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, In CHF thousands ​ 2022 ​ 2021 ​ 2020 Service cost 1,712 1,648 1,626 Interest cost 126 79 71 Interest income (87) (48) (42) Net pension cost 1,751 1,679 1,655 ​ ​ The changes in defined benefit obligation, fair value of plan assets and unrecognized gains/(losses) are as follows. A. Change in defined benefit obligation ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, In CHF thousands 2022 2021 2020 Defined benefit obligation as of January 1 (33,889) (30,213) (26,624) Service cost (1,712) (1,648) (1,626) Interest cost (126) (79) (71) Change in demographic assumptions 29 — 1,428 Change in financial assumptions 8,397 156 (71) Change in experience assumptions (1,726) (252) (931) Benefits deposited (2,327) (894) (1,467) Employees’ contributions (1,056) (959) (851) Defined benefit obligation as of December 31 (32,410) (33,889) (30,213) ​ B. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, In CHF thousands ​ 2022 ​ 2021 ​ 2020 Fair value of plan assets as of January 1 26,791 22,749 19,139 Interest income 87 48 42 Employees’ contributions 1,056 959 851 Employer’s contributions 1,210 1,089 950 Benefits deposited 2,327 894 1,467 Return on plan assets excluding interest income (2,274) 1,052 300 Fair value of plan assets as of December 31 29,197 26,791 22,749 ​ 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 1.2 million. C. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, In CHF thousands ​ 2022 ​ 2021 ​ 2020 Net defined benefit liabilities as of January 1 7,098 7,464 7,485 Net pension cost through statement of income/(loss) 1,751 1,679 1,655 Remeasurement through other comprehensive income/(loss) (4,426) (956) (726) Employer’s contribution (1,210) (1,089) (950) Net defined benefit liabilities as of December 31 3,213 7,098 7,464 ​ D. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, In CHF thousands ​ 2022 ​ 2021 ​ 2020 Effect of changes in demographic assumptions 29 — 1,428 Effect of changes in financial assumptions 8,397 156 (71) Effect of changes in experience assumptions (1,726) (252) (931) Return on plan assets excluding interest income (2,274) 1,052 300 Total other comprehensive gain 4,426 956 726 ​ The change in experience assumptions results from an increased sum of insured salaries. The fair value of the plan assets is the cash surrender value of the insurance with the insurance company (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 14.9 years and 17.1 years as of December 31, 2022 and 2021, 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 years ended December 31, 2022, 2021 and 2020, respectively, are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, ​ 2022 2021 2020 Discount rate 2.25 % 0.30 % 0.20 % Rate of future increase in compensations 1.75 % 1.75 % 1.75 % Rate of future increase in current pensions 0.00 % 0.00 % 0.00 % Interest rate on retirement savings capital 2.25 % 0.75 % 0.50 % Mortality and disability rates BVG 2020-CMI BVG 2020-CMI BVG 2020-CMI ​ ​ In defining the benefits, the minimum requirements of the Swiss 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 assumptions as of December 31, 2022 is shown below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate on ​ ​ Discount rate ​ Future salary increase ​ Future pension cost ​ savings capital ​ ​ 0.5% ​ 0.5% ​ 0.5% ​ 0.5% ​ 0.5% ​ 0.5% ​ 0.5% ​ 0.5% Assumptions increase decrease increase decrease increase decrease increase decrease ​ In CHF thousands Potential defined benefit obligation 30,201 34,916 32,940 31,841 33,601 31,322 33,322 31,545 Decrease/(increase) from actual defined benefit obligation 2,209 (2,506) (530) 569 (1,191) 1,088 (912) 865 ​ A quantitative sensitivity analysis for significant assumptions as of December 31, 2021 is shown below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate on ​ ​ Discount rate ​ Future salary increase ​ Future pension cost ​ savings capital ​ ​ 0.5% ​ 0.5% ​ 0.5% ​ 0.5% ​ 0.5% ​ 0.5% ​ 0.5% ​ 0.5% Assumptions increase decrease increase decrease increase decrease increase decrease ​ in CHF thousands Potential defined benefit obligation 31,190 37,006 34,578 33,176 35,497 32,435 34,822 33,007 Decrease/(increase) from actual defined benefit obligation 2,699 (3,117) (689) 713 (1,608) 1,454 (933) 882 ​ The sensitivity analyses above are subject to limitations and have 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

Share-based compensation	12 Months Ended
	Dec. 31, 2022
Share-based compensation [Abstract]
Share-based compensation	18. Share-based option awards As of December 31, 2022, there are equity-based instruments outstanding that the Company has granted under two different plans. The Company’s 2016 Share Option and Incentive Plan (SOIP) was approved by the shareholders at the ordinary shareholders’ 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 the SOIP as of December 31, 2022. The following table summarizes equity-settled share option grants for plans that existed during the period: ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of ​ ​ options awarded ​ ​ ​ Contractual Plan ​ (since inception) ​ Vesting conditions ​ life of options Share option plan C1 6,775,250 ​ 4 years ’ service from grant date 10 years 2016 SOIP: Executives and directors 3,277,044 1 year , 3 year and 4 years ’ service from the date of grant, quarterly and annually 10 years Employees 1,811,687 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 C1 and the 2016 SOIP are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ Weighted- ​ ​ ​ ​ average ​ average ​ ​ Number of ​ exercise price ​ remaining ​ ​ options ​ (CHF) term (years) Outstanding at January 1, 2020 1,981,629 ​ 5.93 ​ 8.3 Forfeited during the year (53,591) ​ 6.03 ​ — Expired during the year ​ (26,729) ​ 4.38 ​ — Exercised during the year (73,669) ​ 2.00 ​ — Granted during the year 1,073,027 ​ 6.29 ​ — Outstanding at December 31, 2020 2,900,667 ​ 5.90 ​ 8.2 Exercisable at December 31, 2020 1,099,015 ​ 5.49 ​ 7.0 Outstanding at January 1, 2021 2,900,667 ​ 5.90 ​ 8.2 Forfeited during the year (207,331) ​ 6.13 ​ — Exercised during the year (218,561) ​ 4.97 ​ — Granted during the year 1,110,914 ​ 6.34 ​ — Outstanding at December 31, 2021 3,585,689 ​ 6.21 ​ 7.8 Exercisable at December 31, 2021 1,613,242 ​ 6.13 ​ 6.8 Outstanding at January 1, 2022 3,585,689 ​ 6.21 ​ 7.8 Forfeited during the year (304,738) ​ 6.32 ​ — Exercised during the year (110,250) ​ 0.15 ​ — Granted during the year 1,090,316 ​ 3.18 ​ — Outstanding at December 31, 2022 4,261,017 5.65 ​ 7.6 Exercisable at December 31, 2022 2,345,648 6.41 ​ 6.6 ​ The outstanding stock options as of December 31, 2022 have the following range of exercise prices: ​ ​ ​ ​ ​ ​ ​ Range of ​ ​ ​ ​ expiration ​ ​ Total options ​ dates Range of exercise prices CHF 0.15 97,875 2022–2026 CHF 9.53 223,646 2027 USD 5.04 to USD 12.30 2,864,408 2028–2031 USD 2.76 to USD 4.57 ​ 1,075,088 ​ 2032 Total outstanding options 4,261,017 ​ The weighted-average exercise price for options granted in 2022, 2021 and 2020 is USD 3.44 (CHF 3.18), USD 6.95 (CHF 6.34) and USD 7.11 (CHF 6.29), respectively. The range of exercise prices for outstanding options was CHF 0.15 to CHF 9.53 for awards previously granted in CHF (prior to 2018) and USD 2.76 to USD 12.30 for awards granted in USD as of December 31, 2022. For awards issued in 2022, the volatility is based on the Company’s actual volatility for the period congruent with the expected term of the underlying option. The risk-free interest rate is based on yields of long-dated U.S. Treasury notes that align with the expected term of the award. The weighted-average share price of common share options exercised in 2022 is USD 3.55 (CHF 3.28). The weighted-average grant date fair values of the options granted in 2022, 2021 and 2020 are USD 2.38 (CHF 2.20), USD 5.23 (CHF 4.78) and USD 5.25 (CHF 4.65), 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 Year Ended ​ ​ December 31, ​ ​ 2022 ​ 2021 ​ 2020 Exercise price (USD) 2.76-4.57 5.31-7.72 5.04-9.16 ​ Share price (weighted average) 3.44 6.95 7.11 ​ Risk-free interest rate 0-2.4 % 0 % 0 % Expected volatility 67-80 % 80 % 80 % Expected term (in years) 5.5 - 6.25 5.1 - 6 5.5 - 6 ​ Dividend yield — — — ​ ​ Restricted share awards A summary of non-vested share awards (restricted share and restricted share units) activity as of December 31, 2022 and changes during the year then ended is presented below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Contractual ​ ​ Number of ​ ​ ​ life of non- ​ ​ share awards ​ ​ ​ vested share Grantee type ​ granted ​ Vesting conditions ​ awards Restricted share units Directors 159,025 1 year service from date of grant, annually 10 years Executives 274,872 3 year and 4 years ’ service from the date of grant, quarterly and semi-annually 10 years ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ Number of ​ average ​ ​ non-vested ​ grant date fair ​ ​ shares ​ value (CHF) Non-vested at January 1, 2020 42,763 ​ 9.52 Forfeited during the year (11,828) ​ 9.47 Expired during the year (7,804) ​ 9.52 Exercised during the year (84,638) ​ 9.51 Granted during the year — ​ — Vested during the year (23,269) ​ 9.52 Non-vested at December 31, 2020 19,494 ​ 9.51 Vested and exercisable at December 31, 2020 49,289 ​ 9.47 Non-vested at December 31, 2020 19,494 ​ 9.51 Exercised during the year (2,471) ​ 9.46 Vested during the year (18,697) ​ 9.52 Non-vested at December 31, 2021 797 ​ 9.41 Vested and exercisable at December 31, 2021 65,515 ​ 9.48 Non-vested at December 31, 2021 797 ​ 9.41 Granted during the year ​ 239,194 ​ 3.06 Vested during the year (23,505) 3.28 Non-vested at December 31, 2022 216,486 3.06 Vested and exercisable at December 31, 2022 89,020 7.84 ​ The weighted-average grant date fair values of the remaining non-vested share awards as of the respective year end for the restricted share units were CHF 3.06, CHF 9.41 and CHF 9.51 for the years ended December 31, 2022, 2021 and 2020, respectively. The fair values of these non-vested share awards granted were determined using a reasonable estimate of market value of the common shares on the date of the award. The expense charged against the income statement was CHF 3.3 million, CHF 4.1 million and CHF 4.1 million for the years ended December 31, 2022, 2021 and 2020, respectively. The expense is revised by the Company based on the number of instruments that are expected to become exercisable.

Commitments and contingencies

Commitments and contingencies	12 Months Ended
	Dec. 31, 2022
Commitments and contingencies [Abstract]
Commitments and contingencies	19. The Company’s commitments and contingencies relate to its ongoing operating activities, mainly research and development programs, as well as its leased corporate space. 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, 2022, we have contractual obligations, other than for leases (see below), totaling CHF 23.0 million for 2023. We lease our corporate, laboratory and other facilities under multiple 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. The Company recognizes a right-of-use asset for its leases, except for short-term and low-value leases as indicated in Note 3 . ​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ December 31, In CHF thousands 2022 2021 Within 1 year 23,336 19,785 Between 1 and 3 years 18,516 3,620 Between 3 and 5 years 9,229 243 More than 5 years 1,407 51 Total 52,488 23,699 ​

Earnings per share

Earnings per share	12 Months Ended
	Dec. 31, 2022
Earnings per share
Earnings per share	20. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, In CHF thousands except for share and per share data ​ 2022 ​ 2021 ​ 2020 Loss per share (EPS) ​ Numerator ​ ​ Net loss attributable to equity holders of the Company ​ (70,753) (72,996) (61,921) Denominator ​ Weighted-average number of shares outstanding used to compute EPS basic and diluted attributable to equity holders ​ 83,554,412 74,951,833 71,900,212 Basic and diluted loss per share for the period attributable to equity holders ​ (0.85) (0.97) (0.86) ​ In periods for which we have a loss, 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, (ii) non-vested restricted share awards and (iii) shares that were issued upon conversion of two different convertible notes as their inclusion would have been anti-dilutive. The weighted-average number of 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, ​ ​ ​ 2022 ​ 2021 ​ 2020 Share options issued and outstanding (in-the-money) ​ 135,827 1,140,388 412,191 Restricted share awards subject to future vesting ​ 117,292 6,264 28,418 Convertible shares ​ — 41,461 — Total potentially dilutive securities ​ 253,119 1,188,113 440,609 ​

Financial instruments and risk

Financial instruments and risk management	12 Months Ended
	Dec. 31, 2022
Financial instruments and risk management [Abstract]
Financial instruments and risk management	21. 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 ​ 2022 ​ 2021 Financial assets Right-of-use assets 2,808 2,914 Long-term financial assets 361 363 Other current receivables 392 428 Short-term financial assets 91,000 116,000 Cash and cash equivalents 31,586 82,216 Total financial assets 126,147 201,921 ​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ December 31, In CHF thousands ​ 2022 ​ 2021 Financial liabilities Long-term lease liabilities 2,253 2,340 Trade and other payables 929 2,003 Accrued expenses 9,417 16,736 Short-term lease liabilities 548 570 Total financial liabilities 13,147 21,649 ​ 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, with lesser balances of EUR and USD (see “Note 8. Cash and cash equivalents and short-term financial assets”). The Company recognized a gain of CHF 0.5 million and losses of CHF 0.1 million and CHF 0.7 million for the years ended December 31, 2022, 2021 and 2020, respectively, within “Finance result, net.” As of December 31, 2022, 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 0.7 million (2021: CHF 1.7 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) were subject to negative interest rates at certain counterparty thresholds through the first three quarters of 2022. However, with the increase in interest rates, no current CHF cash holdings (inclusive of those held in short-term financial assets) are subject to negative interest rates with our counterparties. As of December 31, 2022 if the interest rates charged by the counterparties had increased/decreased by 10%, the net income for the period would have been higher/lower by less than CHF 0.2 million. Interest income and interest expense are recorded within finance results, net in our consolidated statements of income/(loss). Credit risk The Company maintains a formal treasury risk and investment management policy to limit counterparty credit risk. As of December 31, 2022, the Company’s cash and cash equivalents and short-term financial assets are held with five financial institutions, each with a high credit rating ranging from A+ to BBB assigned by international credit-rating agencies. The maximum amount of credit risk is the carrying amount of the financial assets. Other receivables are fully performing, not past due and not impaired (see “Note 8. Cash and cash equivalents and short-term financial assets” and “Note 10. Other current receivables”). Liquidity risk Inherent in the Company’s business are various risks and uncertainties, including 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 pharmaceutical and biopharmaceutical industries, (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 CHF 0.9 million in trade and other payables, and CHF 9.4 million in accrued expenses which are due within 12 months from the reporting date. Finally, as it relates to the Company’s lease liabilities please see “Note 5. Right-of-use assets, long-term financial assets and lease liabilities” for detail of when corresponding lease liabilities are due.

Capital risk management

Capital risk management	12 Months Ended
	Dec. 31, 2022
Capital risk management [Abstract]
Capital risk management	22. 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 (i) AD, (ii) focused non-Alzheimer’s neurodegenerative diseases including NeuroOrphan indications and (iii) diagnostics.

Subsequent events

Subsequent events	12 Months Ended
	Dec. 31, 2022
Subsequent events
Subsequent events	23. Management has evaluated subsequent events after the balance sheet date, through the issuance of these consolidated financial statements, for appropriate accounting and disclosures. The Company has determined that there were no other such events that warrant disclosure or recognition in these consolidated financial statements.

Summary of significant accoun_2

Summary of significant accounting policies (Policies)	12 Months Ended
	Dec. 31, 2022
Summary of significant accounting policies
Functional and reporting currency	Functional and reporting currency These consolidated financial statements and accompanying notes are presented in Swiss Francs (CHF), which is AC Immune SA’s functional currency and the Group’s reporting currency. The Company’s subsidiary has a functional currency of the U.S. Dollar (USD). The respective functional currency represents the primary economic environment in which the entities operate. The following exchange rates have been used for the translation of the financial statements of AC Immune USA: ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, ​ ​ 2022 2021 2020 CHF/USD Closing rate, USD 1 0.933 0.923 N/A Weighted average exchange rate, USD 1 0.965 0.929 N/A ​ The results and financial position of AC Immune USA are translated into the presentation currency as follows: i. assets and liabilities for each balance sheet presented are translated at the closing rate at the date of that balance sheet; ii. income and expenses for each statement of income/(loss) are translated at average exchange rates; and iii. all resulting exchange differences are recognized in other comprehensive income/(loss), within cumulative translation differences.
Critical judgments and accounting estimates	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 LCAs, (ii) clinical development accruals, (iii) net employee defined benefit liability, (iv) income taxes, (v) share-based compensation, (vi) right-of-use assets and lease liabilities and (vii) our IPR&D asset. 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.
Basis of consolidation	Basis of consolidation The annual closing date of the individual financial statements is December 31. The Company fully-owns its Subsidiary and fully consolidates its financial statements into these consolidated financial statements. All intercompany transactions have been eliminated.
Foreign currency transactions	Foreign currency transactions Foreign currency transactions are translated into the respective functional currency using prevailing exchange rates at the dates of the transactions. Foreign exchange gains and losses resulting from the settlement of such transactions and from the translation at year-end exchange rates of monetary assets and liabilities denominated in foreign currencies are recognized in the consolidated statements of income/(loss). Any gains or losses from these translations are included in the consolidated statements of income/(loss) in the period in which they arise.
Current vs. non-current classification	Current vs. non-current classification The Company presents assets and liabilities in the consolidated balance sheets 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.
Revenue recognition	Revenue recognition The Company applies IFRS 15 Revenue from Contracts with Customers The Company enters into LCAs which are within the scope of IFRS 15, under which it licenses certain rights to its product candidates and intellectual property to third parties. The terms of these arrangements typically include payment to the Company of one or more of the following: non-refundable, upfront 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 intellectual property. Each of these payments results in license, collaboration and other revenues, which are classified as contract revenue on the consolidated statements of income/(loss). 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, upfront 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, upfront 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 cumulative 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 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. 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 consolidated 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 1 year or less. For a complete discussion of accounting for contract revenue, see “Note 13. Contract revenues.”
Research and development expenses	Research and development expenses Given the stage of development of the Company’s products, all research and development expenditure is expensed as incurred as it does not meet the capitalization criteria outlined in IAS 38 Intangible Assets ● 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 preclinical and clinical activities; ● employee-related expenses, including salaries and bonuses, benefits, travel and share-based compensation expenses; and ● all other allocated expenses such as facilities and information technology (IT) costs. For external research contracts, expenses include those associated with contract research organizations, or CROs, or contract manufacturing organizations, or CMOs. The invoicing from CROs or CMOs for services rendered do not always align with work performed. We accrue the cost of services rendered in connection with CRO or CMO activities based on our estimate of the “stage of completion” for such contracted services. We maintain regular communication with our CRO or CMO vendors to gauge the reasonableness of our estimates and accrue expenses as of the balance sheet date in the consolidated financial statements 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.
General and administrative expenses	General and administrative expenses General and administrative expenses are expensed as incurred and include personnel costs, expenses for outside professional services and all other allocated expenses. Personnel costs consist of salaries, cash bonuses, benefits and share-based compensation. Outside professional services consist of legal, accounting and audit services, IT and other consulting fees. Allocated expenses consist of certain IT, facilities and depreciation expenses.
Grant income	Grant income The Company has received grants, from time to time, from the Michael J. Fox Foundation (MJFF), the Target ALS Foundation (Target ALS) and other institutions to support certain research projects. Grants are recorded at their fair value in the consolidated statements of income/(loss) within other operating income/(expenses), net when there is reasonable assurance that the Company will satisfy the underlying grant conditions and the grants will be received. In certain circumstances, grant income may be recognized before formal grantor acknowledgement of milestone achievements. To the extent required, grant income is deferred and recognized on a systematic basis over the periods in which the Company expects to recognize the related expenses for which the grants are intended to compensate.
Leases	Leases The Company applies IFRS 16 Leases Right-of-use assets and lease liabilities At inception of a leasing contract, the Company assesses whether a contract is, or contains, a lease based on whether the contract conveys the right to control the use of an identified asset for a period of time in exchange for consideration. The Company recognizes a right-of-use asset and a lease liability at the lease commencement date. The lease liability is initially measured at the present value of the lease payments that are not paid at the commencement date, discounted using the interest rate implicit in the lease or, if that rate cannot be readily determined, the Company’s incremental borrowing rate. The lease liabilities are classified as current or non-current based on the due dates of the underlying principal payments. Lease payments generally are fixed for the contract term. The lease liability is measured at amortized cost using the effective interest method. The lease liability is re-measured if there is a change in the estimated lease term, a change in future lease payments arising from a change in an index or rate, a change in the Company’s estimate of the amount expected to be payable under a residual value guarantee or a change in assessment of whether it will exercise a purchase, extension or termination option. At inception, the right-of-use asset comprises the initial lease liability and any initial direct costs. The right-of-use asset is depreciated over the shorter of the lease term or the useful life of the underlying asset. The right-of-use asset is periodically reduced by impairment losses, if any, and adjusted for certain re-measurements of the lease liability performed on as certain potential triggering events may arise (e.g. lease modifications). When the lease liability is re-measured, a corresponding adjustment is made to the carrying amount of the right-of-use asset or is recorded in profit or loss if the carrying amount of the right-of-use asset has been reduced to zero. The estimated lease term by right-of-use asset categories are as follows: ​ ​ ​ ​ ​ Buildings 5 years Office equipment ​ 5 years IT equipment ​ 5 years ​ Both the right-of-use-assets and lease liabilities are recognized in the consolidated balance sheets.
Property, plant and equipment	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 consolidated statements of income/(loss).
Intangible assets	Intangible assets AC Immune’s acquired in process research and development (IPR&D) asset is stated at cost less any impairments. The Company does not deem this asset ready for use until the asset obtains market approval. Therefore, during the development period after the date of acquisition until market approval, the IPR&D asset is not amortized. Upon market approval, the Company will determine the useful life of the asset, reclassify it from IPR&D and commence amortization. If the associated R&D effort is abandoned, the related IPR&D will likely be written off and we will record the relevant impairment charge. Finally, the Company will not capitalize future development costs in respect to this IPR&D asset until they meet the criteria for capitalization of research and development costs in accordance with IAS 38 Intangible Assets Our IPR&D asset is subject to impairment testing at least annually or when there are indications that the carrying value may not be recoverable until the completion of the development process. The determination of the recoverable amounts include key estimates which are highly sensitive to, and dependent upon, key assumptions. The Company uses a discounted cash flow method to determine the fair value less costs to sell (recoverable amount) of our IPR&D intangible asset. The Company starts with a forecast of all the expected net cash flows, which incorporates the consideration of a terminal value and then the Company applies a discount rate to arrive at a risk-adjusted net present value amount.
Fair value of financial assets and liabilities	Fair value of financial assets and liabilities The Company’s financial assets and liabilities are composed of receivables, short-term financial assets, cash and cash equivalents, trade payables and lease liabilities. The fair value of these financial instruments approximates 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, unless otherwise explicitly noted. Receivables 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 through 12 months in duration. The Company assesses whether there is objective evidence that financial assets are impaired annually or whenever potential impairment triggers may occur. 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. Trade payables Trade payables are amounts due to third parties in the ordinary course of business.
Share capital and public offerings	Share capital and public offerings Common shares are classified as equity. Share issuance costs are capitalized as incurred and will be shown in equity as a deduction, net of tax, from the proceeds received from existing or future offerings. Should a planned equity offering not be assessed as probable, the issuance costs would be expensed immediately in the consolidated statements of income/(loss). See “Note 11. Share capital.”
Treasury Shares	Treasury shares Treasury shares are recognized at acquisition cost and deducted from shareholders’ equity at the time of acquisition, until they are subsequently resold, distributed or cancelled. Where such shares are subsequently sold, any consideration received is included in shareholders’ equity. See “Note 11. Share capital.”
Employee benefits	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 and pension increases as well as discount rates of highly liquid corporate bonds that have terms to maturity approximating the terms of the related liability. To the extent that the fair value of the plan assets is greater than the present value of the defined benefit obligation as calculated by our independent actuary, the Company accounts for the effect of the asset ceiling test under IAS 19. Re-measurements of the net defined benefit liability, which comprise actuarial gains and losses and the return on plan assets (excluding interest) are recognized immediately in the consolidated statements of other comprehensive income/(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, considering any changes in the net defined benefit liability during the period as a result of contributions and benefit payments. Net interest expense/(income) and other expenses related to defined benefit plans are recognized in the consolidated statements of income/(loss). 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 consolidated statements of income/(loss), and a corresponding adjustment to equity over the remaining vesting period. Stock options granted under the Company’s stock option plans C1 and the 2016 Stock Option and Incentive Plan are valued using the Black-Scholes option-pricing model (see “Note 18. Share-based compensation”). 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 restricted share units using a reasonable estimate of market value of the common shares on the date of the award. We classify our share-based payments as equity-classified awards as they are settled in common shares. We measure equity-classified awards at their grant date fair value and do not subsequently re-measure 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 capital and share premium as the awards vest.
Provisions	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	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 carry-forwards, 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. As disclosed in “Note 16. Income taxes,” 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.
Earnings per share	Earnings per share The Company presents basic earnings per share for each period in the consolidated financial statements. The earnings per share are calculated by dividing the earnings of the period by the weighted-average number of shares outstanding during the period. Diluted earnings per share reflect the potential dilution that could occur if dilutive securities such as share options or non-vested restricted share units 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 the dilutive earnings per share calculation.
Segment reporting	Segment reporting The Company has one segment. The Company currently focuses most 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 operating segment. Non-current assets are located in, and revenue is allocated and recorded within, the Company’s country of domicile, Switzerland.
Accounting policies, new standards, interpretations and amendments adopted by the Company	Accounting policies, new standards, interpretations and amendments adopted by the Company There are no new IFRS standards, amendments or interpretations that are mandatory as of January 1, 2022 that are relevant to the Company. Additionally, the Company has not adopted any standard, interpretation or amendment that has been issued but is not yet effective. Such standards are not currently expected to have a material impact on the entity in the current or future reporting periods and on foreseeable future transactions.

Summary of significant accoun_3

Summary of significant accounting policies (Tables)	12 Months Ended
	Dec. 31, 2022
Summary of significant accounting policies
Schedule of exchange rates used for translation of financial statements	The following exchange rates have been used for the translation of the financial statements of AC Immune USA: ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, ​ ​ 2022 2021 2020 CHF/USD Closing rate, USD 1 0.933 0.923 N/A Weighted average exchange rate, USD 1 0.965 0.929 N/A ​
Estimated Lease Term by Right-of-use Asset Categories	​ ​ ​ ​ ​ Buildings 5 years Office equipment ​ 5 years IT equipment ​ 5 years ​
Estimated useful life	​ ​ ​ ​ ​ IT equipment 3 years Laboratory equipment ​ 5 years Leasehold improvements/furniture ​ 5 years

Property, plant and equipment (

Property, plant and equipment (Tables)	12 Months Ended
	Dec. 31, 2022
Property, plant and equipment.
Schedule of movement in the net book values of property, plant and equipment	The following tables show the movements in the net book values of property, plant and equipment for the years ended December 31, 2022 and 2021, respectively: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2022 ​ ​ ​ IT Laboratory Leasehold Assets under ​ In CHF thousands ​ Furniture ​ equipment ​ equipment ​ improvements ​ construction ​ Total Acquisition cost: Balance at December 31, 2021 265 1,754 9,142 810 695 12,666 Additions 20 151 576 184 5 936 Transfers — 4 47 646 (697) — Balance at December 31, 2022 285 1,909 9,765 1,640 3 13,602 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accumulated depreciation: Balance at December 31, 2021 (106) (1,316) (5,739) (389) — (7,550) Depreciation expenses (53) (283) (1,278) (179) — (1,793) Balance at December 31, 2022 (159) (1,599) (7,017) (568) — (9,343) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Carrying amount: December 31, 2021 159 438 3,403 421 695 5,116 December 31, 2022 126 310 2,748 1,072 3 4,259 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2021 ​ ​ ​ IT Laboratory Leasehold ​ Assets under ​ In CHF thousands ​ Furniture ​ equipment ​ equipment ​ improvements construction ​ Total Acquisition cost: ​ Balance at December 31, 2020 214 1,497 7,681 464 ​ 277 10,133 Additions 51 250 1,268 346 ​ 695 2,610 Transfers ​ — ​ 7 ​ 270 ​ — ​ (277) ​ — Disposals — — (77) — ​ — (77) Balance at December 31, 2021 265 1,754 9,142 810 ​ 695 12,666 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accumulated depreciation: ​ Balance at December 31, 2020 (61) (970) (4,405) (281) ​ — (5,717) Depreciation expenses (45) (346) (1,398) (108) ​ — (1,897) Disposals — — 64 — ​ — 64 Balance at December 31, 2021 (106) (1,316) (5,739) (389) ​ — (7,550) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Carrying amount: ​ December 31, 2020 153 527 3,276 183 ​ 277 4,416 December 31, 2021 159 438 3,403 421 ​ 695 5,116 ​

Right-of-use assets, long-ter_2

Right-of-use assets, long-term financial assets and lease liabilities (Tables)	12 Months Ended
	Dec. 31, 2022
Right-of-use assets, long-term financial assets and lease liabilities
Schedule of the movements in the net value book value of right-of-use assets	The following tables show the movements in the net book values of right-of-use of leased assets for the years ended December 31, 2022 and 2021, respectively: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Office IT ​ In CHF thousands ​ Buildings ​ equipment ​ equipment ​ Total Balance as of December 31, 2021 2,776 98 40 2,914 Additions and remeasurements 460 — — 460 Depreciation (528) (24) (14) (566) Balance as of December 31, 2022 2,708 74 26 2,808 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Office IT ​ In CHF thousands ​ Buildings ​ equipment ​ equipment ​ Total Balance as of December 31, 2020 ​ 2,106 ​ 63 ​ 54 ​ 2,223 Additions and remeasurements 1,144 71 — 1,215 Dispositions ​ — ​ (15) ​ — ​ (15) Depreciation (474) (21) (14) (509) Balance as of December 31, 2021 2,776 98 40 2,914 ​
Schedule of impact on condensed consolidated statements of income/(loss) and cash flows	For the years ended December 31, 2022, and 2021, the impact on the Company’s consolidated statements of income/(loss) and consolidated statements of cash flows is detailed in the table below. ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, In CHF thousands ​ 2022 2021 Statements of income/(loss) ​ Depreciation of right-of-use assets ​ 566 509 Interest expense on lease liabilities ​ 68 63 Expense for short-term leases and leases of low value ​ 750 723 Total ​ 1,384 1,295 ​ ​ ​ ​ ​ Statements of cash flows ​ Total cash outflow for leases ​ 1,388 1,299 ​
Schedule of contractual undiscounted cash flows for lease obligations	The following table presents the contractual undiscounted cash flows for lease liabilities as of December 31, 2022 and 2021: ​ ​ ​ ​ ​ ​ ​ As of ​ ​ December 31, In CHF thousands ​ 2022 2021 Less than one year 638 638 1-3 years 1,230 1,260 3-5 years 1,187 1,203 Total 3,055 3,101 ​

Asset acquisition (Tables)

Asset acquisition (Tables)	12 Months Ended
	Dec. 31, 2022
Asset acquisition
Schedule of Transferred Assets acquired	The following table summarizes the amounts of the Transferred Assets acquired: ​ ​ ​ ​ In CHF thousands Cash 4,634 IPR&D asset 50,416 Total 55,050

Intangible assets (Tables)

Intangible assets (Tables)	12 Months Ended
	Dec. 31, 2022
Intangible assets
Schedule of net book value of intangible assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2022 ​ As of December 31, 2021 ​ Gross ​ ​ Gross ​ ​ ​ ​ carrying ​ Accumulated ​ Net book ​ carrying ​ Accumulated ​ Net book In CHF thousands ​ amount ​ amortization ​ value ​ amount ​ amortization ​ value Acquired IPR&D asset ​ 50,416 — 50,416 50,416 — 50,416 Total intangible assets ​ 50,416 — 50,416 50,416 — 50,416 ​

Cash and cash equivalents and_2

Cash and cash equivalents and short-term financial assets (Tables)	12 Months Ended
	Dec. 31, 2022
Cash and cash equivalents and financial assets
Schedule of cash and cash equivalents by currency	The Company’s cash and cash equivalents are maintained in the following respective currencies as of December 31, 2022 and 2021: ​ ​ ​ ​ ​ ​ ​ As of ​ ​ December 31, In CHF thousands ​ 2022 2021 Cash and cash equivalents 31,586 82,216 Total 31,586 82,216 By currency CHF 24,418 64,941 EUR 1,313 2,253 USD 5,855 15,022 Total cash and cash equivalents 31,586 82,216 ​
Schedule of short-term financial assets	The following table summarizes the Company’s short-term financial assets as of December 31, 2022 and 2021: ​ ​ ​ ​ ​ ​ ​ As of ​ ​ December 31, In CHF thousands ​ 2022 2021 Short-term financial assets due in one year or less 91,000 116,000 Total short-term financial assets 91,000 116,000

Prepaid expenses and accrued _2

Prepaid expenses and accrued income (Tables)	12 Months Ended
	Dec. 31, 2022
Prepaid expenses and accrued income
Prepaid expenses and accrued income	​ ​ ​ ​ ​ ​ ​ As of ​ ​ December 31, In CHF thousands ​ 2022 2021 Prepaid expenses 4,708 3,015 Accrued income 408 975 Total prepaid expenses and accrued income 5,116 3,990 ​

Other current receivables (Tabl

Other current receivables (Tables)	12 Months Ended
	Dec. 31, 2022
Other current receivables [Abstract]
Other current receivables	​ ​ ​ ​ ​ ​ ​ As of ​ ​ December 31, In CHF thousands ​ 2022 2021 Other current receivable 124 101 Swiss VAT 249 327 Withholding tax 19 — Total other current receivables 392 428 ​

Share capital (Tables)

Share capital (Tables)	12 Months Ended
	Dec. 31, 2022
Share capital
Summary of capital structure	The table below summarizes the Company’s capital structure: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ In CHF thousands ​ Common Treasury Share Share Treasury ​ ​ shares ​ shares ​ capital ​ premium ​ shares December 31, 2020 76,936,738 (5,000,000) 1,538 346,890 (100) Proceeds from sale of treasury shares in public offerings, net of underwriting fees and transaction costs — 1,171,543 — 12,097 24 Asset purchase agreement, net of transaction costs 7,106,840 — 142 54,328 — Conversion of note agreements, net of transaction costs ​ 3,026,634 — 61 16,683 — Issuance of shares – incentive plans, net of transaction costs ​ 237,258 — 5 1,253 — Issuance of shares to be held as treasury shares, net of transaction costs 2,393,160 (2,393,160) 48 — (48) December 31, 2021 89,700,630 (6,221,617) 1,794 431,251 (124) Proceeds from sale of treasury shares in public offerings, net of underwriting fees and transaction costs — ​ 7,596 ​ — ​ (8) ​ 0 Issuance of shares – incentive plans, net of transaction costs 133,755 ​ — ​ 3 ​ 80 ​ — December 31, 2022 89,834,385 (6,214,021) 1,797 431,323 (124) ​

Trade and other payables and _2

Trade and other payables and accrued expenses (Tables)	12 Months Ended
	Dec. 31, 2022
Trade and other payables and accrued expenses
Schedule of trade and other payables and accrued expenses	​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ December 31, In CHF thousands ​ 2022 ​ 2021 Trade and other payables 929 2,003 Total trade and other payables 929 2,003 ​ ​ ​ ​ ​ Accrued research and development costs 5,360 10,361 Accrued payroll expenses 2,898 3,562 Other accrued expenses 1,159 2,813 Total accrued expenses 9,417 16,736 ​

Contract revenues (Tables)

Contract revenues (Tables)	12 Months Ended
	Dec. 31, 2022
Contract revenues
Schedule of contract revenues	The following tables provide contract revenue amounts from its LCAs for the years ended December 31, 2022, 2021 and 2020, respectively. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, In CHF thousands 2022 2021 2020 Lilly — — 14,348 Janssen — — 1,083 Life Molecular Imaging 3,935 — — Total contract revenues 3,935 — 15,431 ​
Schedule of contract revenue of performance obligations satisfied	During the years ended December 31, 2022, 2021 and 2020, the Company recognized the following contract revenues as a result of changes in the contract asset and the contract liability balances in the respective periods: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, In CHF thousands ​ 2022 ​ 2021 ​ 2020 Revenues recognized in the period from: Amounts included in the contract liability at the beginning of the period ​ — — 4,477 Performance obligations satisfied in previous periods 3,935 — 10,000 ​

Expenses by category (Tables)

Expenses by category (Tables)	12 Months Ended
	Dec. 31, 2022
Expenses by category [Abstract]
Research and Development	Research and development ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, In CHF thousands 2022 2021 2020 Operating expenses 41,166 44,289 43,787 Payroll expenses 17,548 16,465 14,424 Share-based compensation 1,622 1,528 1,276 Total research and development expenses 60,336 62,282 59,487 ​
General and Administrative	General and administrative ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, In CHF thousands 2022 2021 2020 Operating expenses 6,207 7,031 7,471 Payroll expenses 7,874 8,281 8,274 Share-based compensation 1,708 2,598 2,812 Total general and administrative expenses 15,789 17,910 18,557 ​
Disclosure of finance income (cost) [text block]	Financial result, net ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, In CHF thousands 2022 2021 2020 Financial income 69 6,485 78 Financial expense (355) (581) (184) Exchange differences 393 113 (555) Finance result, net 107 6,017 (661) ​

Related-party transactions (Tab

Related-party transactions (Tables)	12 Months Ended
	Dec. 31, 2022
Related-party transactions [Abstract]
Key management compensation	Key management includes the board of directors and executive management. For 2022, there were eight members (2021: eight and 2020: seven) of the Board (excluding the CEO) and seven members (2021: six and 2020: five) of executive management (including the CEO). Compensation was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, In CHF thousands ​ 2022 ​ 2021 ​ 2020 Short-term employee benefits 4,187 4,403 3,497 Post-employment benefits 295 266 214 Share-based compensation 2,503 2,997 2,578 Total compensation 6,985 7,666 6,289

Income taxes (Tables)

Income taxes (Tables)	12 Months Ended
	Dec. 31, 2022
Income taxes [Abstract]
Income tax expense reconciled to loss	The Group’s income tax expense for each year can be reconciled to loss before tax as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, In CHF thousands 2022 2021 2020 Loss before income tax (70,740) (72,993) (61,921) Tax benefit calculated at the domestic rates applicable in the respective countries (9,616) (9,930) (8,441) (Income not subject to tax)/expenses not deductible for tax purposes 455 (375) 462 Effect of unused tax losses and tax offsets not recognized as deferred tax assets 9,174 10,308 7,979 Effective income tax rate (benefit)/expense 13 3 — ​
Unrecognized deductible temporary differences, unused tax losses and unused tax credits	The below table details the total unrecognized deductible temporary differences, unused tax losses and unused tax credits: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ December 31, In CHF thousands 2022 2021 2020 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 264,089 197,152 121,948 Deductible temporary differences related to: Right-of-use assets and lease liabilities, net — — — Retirement benefit plan 3,213 7,098 7,464 Total 267,302 204,250 129,412 ​
Tax losses carry forwards and respective expiry dates	The following table details the tax losses carry forwards of the Company and their respective expiry dates: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ December 31, In CHF thousands ​ 2022 ​ 2021 ​ 2020 Tax losses split by expiry date: December 31, 2024 ​ 15,231 ​ 15,231 15,231 December 31, 2025 48,894 48,894 48,894 December 31, 2026 — — — December 31, 2027 57,824 57,824 57,824 December 31, 2028 75,204 75,204 — December 31, 2029 66,936 — — Total unrecorded tax loss carryforwards 264,089 197,153 121,949 ​

Retirement benefit plan (Tables

Retirement benefit plan (Tables)	12 Months Ended
	Dec. 31, 2022
Retirement benefit plan
Schedule of amounts recognized in balance sheet from defined benefit plans	The following table sets forth the status of the defined benefit pension plan and the amount that is recognized in the consolidated balance sheets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ December 31, In CHF thousands ​ 2022 ​ 2021 ​ 2020 Defined benefit obligation (32,410) (33,889) (30,213) Fair value of plan assets 29,197 26,791 22,749 Total liability (3,213) (7,098) (7,464) ​
Schedule of amounts recognized in statement of profit and loss from defined benefit plans	The following amounts have been recorded as net pension cost in the consolidated statements of income/(loss): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, In CHF thousands ​ 2022 ​ 2021 ​ 2020 Service cost 1,712 1,648 1,626 Interest cost 126 79 71 Interest income (87) (48) (42) Net pension cost 1,751 1,679 1,655 ​
Schedule of changes in defined benefit obligations, fair value of plan assets and net defined benefit liability	​ The changes in defined benefit obligation, fair value of plan assets and unrecognized gains/(losses) are as follows. A. Change in defined benefit obligation ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, In CHF thousands 2022 2021 2020 Defined benefit obligation as of January 1 (33,889) (30,213) (26,624) Service cost (1,712) (1,648) (1,626) Interest cost (126) (79) (71) Change in demographic assumptions 29 — 1,428 Change in financial assumptions 8,397 156 (71) Change in experience assumptions (1,726) (252) (931) Benefits deposited (2,327) (894) (1,467) Employees’ contributions (1,056) (959) (851) Defined benefit obligation as of December 31 (32,410) (33,889) (30,213) ​ B. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, In CHF thousands ​ 2022 ​ 2021 ​ 2020 Fair value of plan assets as of January 1 26,791 22,749 19,139 Interest income 87 48 42 Employees’ contributions 1,056 959 851 Employer’s contributions 1,210 1,089 950 Benefits deposited 2,327 894 1,467 Return on plan assets excluding interest income (2,274) 1,052 300 Fair value of plan assets as of December 31 29,197 26,791 22,749 ​ 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 1.2 million. C. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, In CHF thousands ​ 2022 ​ 2021 ​ 2020 Net defined benefit liabilities as of January 1 7,098 7,464 7,485 Net pension cost through statement of income/(loss) 1,751 1,679 1,655 Remeasurement through other comprehensive income/(loss) (4,426) (956) (726) Employer’s contribution (1,210) (1,089) (950) Net defined benefit liabilities as of December 31 3,213 7,098 7,464 ​
Schedule of amounts recognized in statement of other comprehensive income from defined benefit plans	D. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, In CHF thousands ​ 2022 ​ 2021 ​ 2020 Effect of changes in demographic assumptions 29 — 1,428 Effect of changes in financial assumptions 8,397 156 (71) Effect of changes in experience assumptions (1,726) (252) (931) Return on plan assets excluding interest income (2,274) 1,052 300 Total other comprehensive gain 4,426 956 726 ​
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 years ended December 31, 2022, 2021 and 2020, respectively, are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, ​ 2022 2021 2020 Discount rate 2.25 % 0.30 % 0.20 % Rate of future increase in compensations 1.75 % 1.75 % 1.75 % Rate of future increase in current pensions 0.00 % 0.00 % 0.00 % Interest rate on retirement savings capital 2.25 % 0.75 % 0.50 % Mortality and disability rates BVG 2020-CMI BVG 2020-CMI BVG 2020-CMI ​ ​ A quantitative sensitivity analysis for significant assumptions as of December 31, 2022 is shown below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate on ​ ​ Discount rate ​ Future salary increase ​ Future pension cost ​ savings capital ​ ​ 0.5% ​ 0.5% ​ 0.5% ​ 0.5% ​ 0.5% ​ 0.5% ​ 0.5% ​ 0.5% Assumptions increase decrease increase decrease increase decrease increase decrease ​ In CHF thousands Potential defined benefit obligation 30,201 34,916 32,940 31,841 33,601 31,322 33,322 31,545 Decrease/(increase) from actual defined benefit obligation 2,209 (2,506) (530) 569 (1,191) 1,088 (912) 865 ​ A quantitative sensitivity analysis for significant assumptions as of December 31, 2021 is shown below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate on ​ ​ Discount rate ​ Future salary increase ​ Future pension cost ​ savings capital ​ ​ 0.5% ​ 0.5% ​ 0.5% ​ 0.5% ​ 0.5% ​ 0.5% ​ 0.5% ​ 0.5% Assumptions increase decrease increase decrease increase decrease increase decrease ​ in CHF thousands Potential defined benefit obligation 31,190 37,006 34,578 33,176 35,497 32,435 34,822 33,007 Decrease/(increase) from actual defined benefit obligation 2,699 (3,117) (689) 713 (1,608) 1,454 (933) 882 ​

Share-based compensation (Table

Share-based compensation (Tables)	12 Months Ended
	Dec. 31, 2022
Share-based compensation [Abstract]
Share-based compensation plans outstanding	The following table summarizes equity-settled share option grants for plans that existed during the period: ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of ​ ​ options awarded ​ ​ ​ Contractual Plan ​ (since inception) ​ Vesting conditions ​ life of options Share option plan C1 6,775,250 ​ 4 years ’ service from grant date 10 years 2016 SOIP: Executives and directors 3,277,044 1 year , 3 year and 4 years ’ service from the date of grant, quarterly and annually 10 years Employees 1,811,687 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 C1 and the 2016 SOIP are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ Weighted- ​ ​ ​ ​ average ​ average ​ ​ Number of ​ exercise price ​ remaining ​ ​ options ​ (CHF) term (years) Outstanding at January 1, 2020 1,981,629 ​ 5.93 ​ 8.3 Forfeited during the year (53,591) ​ 6.03 ​ — Expired during the year ​ (26,729) ​ 4.38 ​ — Exercised during the year (73,669) ​ 2.00 ​ — Granted during the year 1,073,027 ​ 6.29 ​ — Outstanding at December 31, 2020 2,900,667 ​ 5.90 ​ 8.2 Exercisable at December 31, 2020 1,099,015 ​ 5.49 ​ 7.0 Outstanding at January 1, 2021 2,900,667 ​ 5.90 ​ 8.2 Forfeited during the year (207,331) ​ 6.13 ​ — Exercised during the year (218,561) ​ 4.97 ​ — Granted during the year 1,110,914 ​ 6.34 ​ — Outstanding at December 31, 2021 3,585,689 ​ 6.21 ​ 7.8 Exercisable at December 31, 2021 1,613,242 ​ 6.13 ​ 6.8 Outstanding at January 1, 2022 3,585,689 ​ 6.21 ​ 7.8 Forfeited during the year (304,738) ​ 6.32 ​ — Exercised during the year (110,250) ​ 0.15 ​ — Granted during the year 1,090,316 ​ 3.18 ​ — Outstanding at December 31, 2022 4,261,017 5.65 ​ 7.6 Exercisable at December 31, 2022 2,345,648 6.41 ​ 6.6 ​
Outstanding options, exercise price range and expiry dates	The outstanding stock options as of December 31, 2022 have the following range of exercise prices: ​ ​ ​ ​ ​ ​ ​ Range of ​ ​ ​ ​ expiration ​ ​ Total options ​ dates Range of exercise prices CHF 0.15 97,875 2022–2026 CHF 9.53 223,646 2027 USD 5.04 to USD 12.30 2,864,408 2028–2031 USD 2.76 to USD 4.57 ​ 1,075,088 ​ 2032 Total outstanding options 4,261,017 ​
Weighted-average assumptions	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, ​ ​ 2022 ​ 2021 ​ 2020 Exercise price (USD) 2.76-4.57 5.31-7.72 5.04-9.16 ​ Share price (weighted average) 3.44 6.95 7.11 ​ Risk-free interest rate 0-2.4 % 0 % 0 % Expected volatility 67-80 % 80 % 80 % Expected term (in years) 5.5 - 6.25 5.1 - 6 5.5 - 6 ​ 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, 2022 and changes during the year then ended is presented below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Contractual ​ ​ Number of ​ ​ ​ life of non- ​ ​ share awards ​ ​ ​ vested share Grantee type ​ granted ​ Vesting conditions ​ awards Restricted share units Directors 159,025 1 year service from date of grant, annually 10 years Executives 274,872 3 year and 4 years ’ service from the date of grant, quarterly and semi-annually 10 years ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ Number of ​ average ​ ​ non-vested ​ grant date fair ​ ​ shares ​ value (CHF) Non-vested at January 1, 2020 42,763 ​ 9.52 Forfeited during the year (11,828) ​ 9.47 Expired during the year (7,804) ​ 9.52 Exercised during the year (84,638) ​ 9.51 Granted during the year — ​ — Vested during the year (23,269) ​ 9.52 Non-vested at December 31, 2020 19,494 ​ 9.51 Vested and exercisable at December 31, 2020 49,289 ​ 9.47 Non-vested at December 31, 2020 19,494 ​ 9.51 Exercised during the year (2,471) ​ 9.46 Vested during the year (18,697) ​ 9.52 Non-vested at December 31, 2021 797 ​ 9.41 Vested and exercisable at December 31, 2021 65,515 ​ 9.48 Non-vested at December 31, 2021 797 ​ 9.41 Granted during the year ​ 239,194 ​ 3.06 Vested during the year (23,505) 3.28 Non-vested at December 31, 2022 216,486 3.06 Vested and exercisable at December 31, 2022 89,020 7.84 ​

Commitments and contingencies (

Commitments and contingencies (Tables)	12 Months Ended
	Dec. 31, 2022
Commitments and contingencies [Abstract]
Schedule of commitments	​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ December 31, In CHF thousands 2022 2021 Within 1 year 23,336 19,785 Between 1 and 3 years 18,516 3,620 Between 3 and 5 years 9,229 243 More than 5 years 1,407 51 Total 52,488 23,699

Earnings per share (Tables)

Earnings per share (Tables)	12 Months Ended
	Dec. 31, 2022
Earnings per share
Schedule of earnings per share	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, In CHF thousands except for share and per share data ​ 2022 ​ 2021 ​ 2020 Loss per share (EPS) ​ Numerator ​ ​ Net loss attributable to equity holders of the Company ​ (70,753) (72,996) (61,921) Denominator ​ Weighted-average number of shares outstanding used to compute EPS basic and diluted attributable to equity holders ​ 83,554,412 74,951,833 71,900,212 Basic and diluted loss per share for the period attributable to equity holders ​ (0.85) (0.97) (0.86) ​
Schedule of antidilutive securities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ ​ December 31, ​ ​ ​ 2022 ​ 2021 ​ 2020 Share options issued and outstanding (in-the-money) ​ 135,827 1,140,388 412,191 Restricted share awards subject to future vesting ​ 117,292 6,264 28,418 Convertible shares ​ — 41,461 — Total potentially dilutive securities ​ 253,119 1,188,113 440,609

Financial instruments and ris_2

Financial instruments and risk management (Tables)	12 Months Ended
	Dec. 31, 2022
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 ​ 2022 ​ 2021 Financial assets Right-of-use assets 2,808 2,914 Long-term financial assets 361 363 Other current receivables 392 428 Short-term financial assets 91,000 116,000 Cash and cash equivalents 31,586 82,216 Total financial assets 126,147 201,921 ​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ December 31, In CHF thousands ​ 2022 ​ 2021 Financial liabilities Long-term lease liabilities 2,253 2,340 Trade and other payables 929 2,003 Accrued expenses 9,417 16,736 Short-term lease liabilities 548 570 Total financial liabilities 13,147 21,649 ​

General information (Details)

General information (Details)	Dec. 31, 2022 item
General information
Number of proprietary technology platforms	2

Basis of preparation - Going co

Basis of preparation - Going concern (Details) - CHF (SFr) SFr in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Going concern [Abstract]
Company's cash position	SFr 31,586	SFr 82,216	SFr 160,893	SFr 193,587
Short-term financial assets	SFr 91,000	SFr 116,000

Summary of significant accoun_4

Summary of significant accounting policies - Functional and reporting currency (Details) - SFr / $	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Functional and reporting currency [Abstract]
Closing rate, USD 1	0.933	0.923
Weighted average exchange rate, USD 1	0.965	0.929

Summary of significant accoun_5

Summary of significant accounting policies, Right-of-use assets and lease liabilities (Details)	12 Months Ended
	Dec. 31, 2022
Buildings [Member]
Right-of-use assets and lease liabilities:
Estimated lease term	5 years
Office Equipment [Member]
Right-of-use assets and lease liabilities:
Estimated lease term	5 years
IT Equipment
Right-of-use assets and lease liabilities:
Estimated lease term	5 years

Summary of significant accoun_6

Summary of significant accounting policies, Property, plant and equipment (Details)	12 Months Ended
	Dec. 31, 2022
IT Equipment
Estimated useful life [Abstract]
Estimated useful life	3 years
Lab Equipment
Estimated useful life [Abstract]
Estimated useful life	5 years
Leasehold Improvements/Furniture [Member]
Estimated useful life [Abstract]
Estimated useful life	5 years

Summary of significant accoun_7

Summary of significant accounting policies, Income taxes (Details) SFr in Thousands	12 Months Ended
	Dec. 31, 2022 CHF (SFr)
Income taxes [Abstract]
Tax loss carryforward period	7 years
Deferred tax assets	SFr 0

Summary of significant accoun_8

Summary of significant accounting policies, Segment reporting (Details)	12 Months Ended
	Dec. 31, 2022 segment
Segment reporting [Abstract]
Number of operating segments	1
Number of reportable segments	1

Property, plant and equipment_2

Property, plant and equipment (Details) - CHF (SFr) SFr in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Property, plant and equipment:
Property, plant and equipment, beginning of period	SFr 5,116	SFr 4,416
Property, plant and equipment, end of period	4,259	5,116	SFr 4,416
Acquisition Cost
Property, plant and equipment:
Property, plant and equipment, beginning of period	12,666	10,133
Additions	936	2,610
Transfers	0
Disposals		(77)
Property, plant and equipment, end of period	13,602	12,666	10,133
Accumulated depreciation
Property, plant and equipment:
Property, plant and equipment, beginning of period	(7,550)	(5,717)
Depreciation expense	(1,793)	(1,897)	(1,500)
Disposals		64
Property, plant and equipment, end of period	(9,343)	(7,550)	(5,717)
Furniture
Property, plant and equipment:
Property, plant and equipment, beginning of period	159	153
Property, plant and equipment, end of period	126	159	153
Furniture | Acquisition Cost
Property, plant and equipment:
Property, plant and equipment, beginning of period	265	214
Additions	20	51
Transfers	0
Disposals		0
Property, plant and equipment, end of period	285	265	214
Furniture | Accumulated depreciation
Property, plant and equipment:
Property, plant and equipment, beginning of period	(106)	(61)
Depreciation expense	(53)	(45)
Disposals		0
Property, plant and equipment, end of period	(159)	(106)	(61)
IT Equipment
Property, plant and equipment:
Property, plant and equipment, beginning of period	438	527
Property, plant and equipment, end of period	310	438	527
IT Equipment | Acquisition Cost
Property, plant and equipment:
Property, plant and equipment, beginning of period	1,754	1,497
Additions	151	250
Transfers	4	7
Disposals		0
Property, plant and equipment, end of period	1,909	1,754	1,497
IT Equipment | Accumulated depreciation
Property, plant and equipment:
Property, plant and equipment, beginning of period	(1,316)	(970)
Depreciation expense	(283)	(346)
Disposals		0
Property, plant and equipment, end of period	(1,599)	(1,316)	(970)
Lab Equipment
Property, plant and equipment:
Property, plant and equipment, beginning of period	3,403	3,276
Additions	800
Property, plant and equipment, end of period	SFr 2,748	3,403	3,276
Percentage of increase in equipment	7%
Lab Equipment | Acquisition Cost
Property, plant and equipment:
Property, plant and equipment, beginning of period	SFr 9,142	7,681
Additions	576	1,268
Transfers	47	270
Disposals		(77)
Property, plant and equipment, end of period	9,765	9,142	7,681
Lab Equipment | Accumulated depreciation
Property, plant and equipment:
Property, plant and equipment, beginning of period	(5,739)	(4,405)
Depreciation expense	(1,278)	(1,398)
Disposals		64
Property, plant and equipment, end of period	(7,017)	(5,739)	(4,405)
Leasehold Improvements
Property, plant and equipment:
Property, plant and equipment, beginning of period	421	183
Property, plant and equipment, end of period	1,072	421	183
Leasehold Improvements | Acquisition Cost
Property, plant and equipment:
Property, plant and equipment, beginning of period	810	464
Additions	184	346
Transfers	646
Disposals		0
Property, plant and equipment, end of period	1,640	810	464
Leasehold Improvements | Accumulated depreciation
Property, plant and equipment:
Property, plant and equipment, beginning of period	(389)	(281)
Depreciation expense	(179)	(108)
Disposals		0
Property, plant and equipment, end of period	(568)	(389)	(281)
Assets under construction
Property, plant and equipment:
Property, plant and equipment, beginning of period	695
Property, plant and equipment, end of period	3	695
Assets under construction | Acquisition Cost
Property, plant and equipment:
Property, plant and equipment, beginning of period	695
Additions	5
Transfers	(697)
Property, plant and equipment, end of period	3	695
Assets Under Construction
Property, plant and equipment:
Property, plant and equipment, beginning of period	695	277
Property, plant and equipment, end of period		695	277
Assets Under Construction | Acquisition Cost
Property, plant and equipment:
Property, plant and equipment, beginning of period	SFr 695	277
Additions		695
Transfers		(277)
Disposals		0
Property, plant and equipment, end of period		695	SFr 277
Assets Under Construction | Accumulated depreciation
Property, plant and equipment:
Disposals		SFr 0

Right-of-use assets, long-ter_3

Right-of-use assets, long-term financial assets and lease liabilities (Details) - CHF (SFr) SFr in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Right-of-use assets and lease liabilities:
Additions and remeasurements	SFr 460	SFr 1,215
Right-of-use of leased assets:
Balance, beginning of period	2,914	2,223
Depreciation	(566)	(509)
Dispositions		(15)
Balance, end of period	2,808	2,914
Buildings
Right-of-use assets and lease liabilities:
Additions and remeasurements	SFr 460	SFr 1,144
Weighted average incremental borrowing rate	3.50%	2.50%
Right-of-use of leased assets:
Balance, beginning of period	SFr 2,776	SFr 2,106
Depreciation	(528)	(474)
Balance, end of period	2,708	2,776
Office Equipment
Right-of-use assets and lease liabilities:
Additions and remeasurements	SFr 0	SFr 71
Weighted average incremental borrowing rate	5.30%	5.30%
Right-of-use of leased assets:
Balance, beginning of period	SFr 98	SFr 63
Depreciation	(24)	(21)
Dispositions		(15)
Balance, end of period	74	98
IT Equipment
Right-of-use assets and lease liabilities:
Additions and remeasurements	SFr 0	SFr 0
Weighted average incremental borrowing rate	2.60%	2.60%
Right-of-use of leased assets:
Balance, beginning of period	SFr 40	SFr 54
Depreciation	(14)	(14)
Balance, end of period	SFr 26	SFr 40

Right-of-use assets, long-ter_4

Right-of-use assets, long-term financial assets and lease liabilities - Statement of income/(loss) and cash flow (Details) - CHF (SFr) SFr in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Statements of income/(loss) and cash flows
Depreciation of right-of-use assets	SFr 566	SFr 509
Interest expense on lease liabilities	68	63
Expense for short-term leases and leases of low value	750	723
Total	1,384	1,295
Total cash outflow for leases	SFr 1,388	SFr 1,299

Right-of-use assets, long-ter_5

Right-of-use assets, long-term financial assets and lease liabilities - Contractual undiscounted cash flows for lease obligations (Details) SFr in Thousands	Dec. 31, 2022 CHF (SFr) item	Dec. 31, 2021 CHF (SFr)
Contractual undiscounted cash flows for lease liabilities:
Contractual undiscounted cash flows for lease liabilities	SFr 3,055	SFr 3,101
Number of deposits in escrow accounts | item	2
Escrow deposits	SFr 400
Less than one year
Contractual undiscounted cash flows for lease liabilities:
Contractual undiscounted cash flows for lease liabilities	638	638
1-3 years
Contractual undiscounted cash flows for lease liabilities:
Contractual undiscounted cash flows for lease liabilities	1,230	1,260
3-5 years
Contractual undiscounted cash flows for lease liabilities:
Contractual undiscounted cash flows for lease liabilities	SFr 1,187	SFr 1,203

Asset acquisition (Details)

Asset acquisition (Details) - Program portfolio of therapeutics targeting asyn from Affiris SFr in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($) shares	Dec. 31, 2021 CHF (SFr)
Disclosure of detailed information about intangible assets [line items]
Shares transferred as consideration in asset acquisition | shares	7,106,840
Total consideration transferred, acquisition-date fair value, asset acquisition	$ 58.7	SFr 55,100
Cash	5	4,634
IPR&D asset		50,416
Total assets acquired		55,050
IPR&D intangible asset associated with ACI 7104.056
Disclosure of detailed information about intangible assets [line items]
IPR&D asset	$ 53.7	SFr 50,400
IPR&D intangible asset associated with ACI 7104.056 | Discount rate, measurement input
Disclosure of detailed information about intangible assets [line items]
Discount rate	0.15	0.15

Intangible assets (Details)

Intangible assets (Details) SFr in Thousands	Dec. 31, 2022 CHF (SFr)	Dec. 31, 2021 CHF (SFr)
Disclosure of intangible assets material to entity [abstract]
Intangible Assets	SFr 50,416	SFr 50,416
Gross Carrying Amount
Disclosure of intangible assets material to entity [abstract]
Intangible Assets	50,416	50,416
Accumulated Amortization
Disclosure of intangible assets material to entity [abstract]
Intangible Assets	0	0
Acquired IPR&D Asset
Disclosure of intangible assets material to entity [abstract]
Intangible Assets	SFr 50,416	SFr 50,416
Acquired IPR&D Asset | Discount rate, measurement input
Disclosure of intangible assets material to entity [abstract]
Discount rate	0.17	0.15
Acquired IPR&D Asset | Gross Carrying Amount
Disclosure of intangible assets material to entity [abstract]
Intangible Assets	SFr 50,416	SFr 50,416
Acquired IPR&D Asset | Accumulated Amortization
Disclosure of intangible assets material to entity [abstract]
Intangible Assets	SFr 0	SFr 0

Cash and cash equivalents and f

Cash and cash equivalents and financial assets, Cash and cash equivalents (Details) SFr in Thousands	Dec. 31, 2022 CHF (SFr) SFr / € SFr / $	Dec. 31, 2021 CHF (SFr) SFr / $ SFr / €	Dec. 31, 2020 CHF (SFr)	Dec. 31, 2019 CHF (SFr)
Cash and cash equivalents [Abstract]
Cash and cash equivalents	SFr 31,586	SFr 82,216	SFr 160,893	SFr 193,587
Translation rate into CHF | SFr / $	0.933	0.923
CHF [Member]
Cash and cash equivalents [Abstract]
Cash and cash equivalents	SFr 24,418	SFr 64,941
EUR [Member]
Cash and cash equivalents [Abstract]
Cash and cash equivalents	SFr 1,313	SFr 2,253
Translation rate into CHF | SFr / €	0.994	1.045
USD [Member]
Cash and cash equivalents [Abstract]
Cash and cash equivalents	SFr 5,855	SFr 15,022
Translation rate into CHF | SFr / $	0.933	0.923

Cash and cash equivalents and_3

Cash and cash equivalents and financial assets, Cash and cash equivalents and short-term financial assets (Details) - CHF (SFr) SFr in Thousands	Dec. 31, 2022	Dec. 31, 2021
Cash and cash equivalents and financial assets
Short-term financial assets due in one year or less	SFr 91,000	SFr 116,000

Prepaid expenses and accrued _3

Prepaid expenses and accrued income (Details) - CHF (SFr) SFr in Thousands	Dec. 31, 2022	Dec. 31, 2021
Prepaid expenses and accrued income [Abstract]
Prepaid expenses	SFr 4,708	SFr 3,015
Accrued income	408	975
Total prepaid expenses and accrued income	5,116	3,990
Grants, Michael J. Fox Foundation and Target ALS
Prepaid expenses and accrued income [Abstract]
Accrued income	SFr 400
Percentage of accrued income	100%
Grants, Michael J. Fox Foundation [Member]
Prepaid expenses and accrued income [Abstract]
Accrued income	SFr 300	SFr 900
Percentage of accrued income		87%

Other current receivables (Deta

Other current receivables (Details) - CHF (SFr) SFr in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Other current receivables [abstract]
Other current receivable	SFr 124	SFr 101
Swiss VAT	249	327
Withholding tax	19	0
Total other current receivables	SFr 392	SFr 428
Top of Range [Member]
Other current receivables [abstract]
Maturity period, other current receivables	3 months

Share capital - Narratives (Det

Share capital - Narratives (Details) - CHF (SFr)	Dec. 31, 2022	Dec. 31, 2021
Disclosure of classes of share capital [line items]
Issued share capital	SFr 1,797,000	SFr 1,794,000
Number of treasury shares outstanding	6,214,021	6,221,617
Common Shares [Member]
Disclosure of classes of share capital [line items]
Issued share capital	SFr 1,796,675	SFr 1,794,013
Number of shares	83,620,364	83,479,013

Share capital - Capital Structu

Share capital - Capital Structure (Details) - CHF (SFr) SFr / shares in Units, SFr in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Treasury shares
Treasury shares outstanding at beginning of period	(6,221,617)
Treasury shares outstanding at end of period	(6,214,021)	(6,221,617)
Changes in equity
Balance, beginning of period	SFr 231,979	SFr 215,478	SFr 272,442
Proceeds from sale of treasury shares in public offerings, net of underwriting fees and transaction costs	(8)	12,121
Conversion of note agreements, net of transaction costs		16,744
Issuance of shares to be held as treasury shares, net of transaction costs		0	0
Balance, end of period	SFr 168,991	SFr 231,979	SFr 215,478
Nominal value per share (in CHF per share)	SFr 0.02
Common Shares
Common shares
Common shares outstanding at beginning of period	89,700,630	76,936,738
Asset purchase agreement, net of transaction costs (in shares)		7,106,840
Conversion of note agreement, net of transaction costs (in shares)		3,026,634
Issuance of shares - incentive plans, net of transaction costs (in shares)	133,755	237,258
Issuance of shares to be held as treasury shares, net of transaction costs (in shares)		2,393,160
Common shares outstanding at end of period	89,834,385	89,700,630	76,936,738
Treasury shares
Issuance of shares to be held as treasury shares, net of transaction costs (in shares)		2,393,160
Treasury shares
Common shares
Issuance of shares to be held as treasury shares, net of transaction costs (in shares)		2,393,160
Treasury shares
Treasury shares outstanding at beginning of period	(6,221,617)	(5,000,000)
Issuance of shares to be held as treasury shares, net of transaction costs (in shares)		2,393,160
Proceeds from sale of treasury shares in public offerings, net of underwriting fees and transaction costs (in shares)	7,596	1,171,543
Treasury shares outstanding at end of period	(6,214,021)	(6,221,617)	(5,000,000)
Share capital
Changes in equity
Balance, beginning of period	SFr 1,794	SFr 1,538	SFr 1,437
Asset purchase agreement, net of transaction costs		142
Conversion of note agreements, net of transaction costs		61
Issuance of shares - incentive plans, net of transaction costs	3	5
Issuance of shares to be held as treasury shares, net of transaction costs		48	100
Balance, end of period	1,797	1,794	1,538
Share premium
Changes in equity
Balance, beginning of period	431,251	346,890	346,526
Proceeds from sale of treasury shares in public offerings, net of underwriting fees and transaction costs	(8)	12,097
Asset purchase agreement, net of transaction costs		54,328
Conversion of note agreements, net of transaction costs		16,683
Issuance of shares - incentive plans, net of transaction costs	80	1,253
Issuance of shares to be held as treasury shares, net of transaction costs		0	0
Balance, end of period	431,323	431,251	346,890
Treasury shares
Changes in equity
Balance, beginning of period	(124)	(100)	0
Proceeds from sale of treasury shares in public offerings, net of underwriting fees and transaction costs	0	24
Issuance of shares to be held as treasury shares, net of transaction costs		(48)	(100)
Balance, end of period	SFr (124)	SFr (124)	SFr (100)

Share capital - Authorized capi

Share capital - Authorized capital (Details)	12 Months Ended
	Dec. 31, 2022 CHF (SFr) SFr / shares shares
Share capital
Additional share capital that Board of Directors are authorized to issue | SFr	SFr 400,000
Number of additional shares that Board of Directors are authorized to issue | shares	20,000,000
Nominal value per share (in CHF per share) | SFr / shares	SFr 0.02

Share capital - Conditional sha

Share capital - Conditional share capital for bonds and similar debt instruments (Details)	12 Months Ended
	Dec. 31, 2022 CHF (SFr) SFr / shares shares
Conditional Share Capital [Abstract]
Nominal value per share (in CHF per share)	SFr 0.02
Bonds and Similar Debt Instruments [Member]
Conditional Share Capital [Abstract]
Nominal value per share (in CHF per share)	SFr 0.02
Bonds and Similar Debt Instruments [Member] | Top of Range [Member]
Conditional Share Capital [Abstract]
Potential increase is equity through conversion of debt instruments | SFr	SFr 100,000
Potential number of shares issued from conversion of debt instruments | shares	5,000,000

Share capital - Conditional s_2

Share capital - Conditional share capital for employee benefit plans (Details)	12 Months Ended
	Dec. 31, 2022 CHF (SFr) SFr / shares shares
Conditional Share Capital [Abstract]
Nominal value per share (in CHF per share)	SFr 0.02
Employee Benefit Plans [Member]
Conditional Share Capital [Abstract]
Nominal value per share (in CHF per share)	SFr 0.02
Employee Benefit Plans [Member] | Top of Range [Member]
Conditional Share Capital [Abstract]
Maximum aggregate amount of ordinary shares | SFr	SFr 96,000
Issuance of ordinary shares (in shares) | shares	4,800,000

Share capital - Shelf registrat

Share capital - Shelf registration statement (Details)	Apr. 28, 2021 CHF (SFr)
Top of Range [Member]
Disclosure of classes of share capital [line items]
Capital authorized to be issued under Shelf Registration Statement	SFr 350,000,000

Share capital - At the market e

Share capital - At the market equity offering (Details) SFr / shares in Units, SFr in Thousands, $ in Millions	3 Months Ended			12 Months Ended
	Sep. 30, 2021 SFr / shares shares	Sep. 30, 2020 CHF (SFr) SFr / shares shares	Sep. 30, 2020 USD ($) shares	Dec. 31, 2022 CHF (SFr) SFr / shares shares	Dec. 31, 2022 USD ($) shares	Dec. 31, 2021 CHF (SFr)	Dec. 31, 2020 CHF (SFr)
At the Market Equity Offering [Abstract]
Nominal value per share (in CHF per share) | SFr / shares				SFr 0.02
Issuance costs | SFr				SFr 0		SFr 776	SFr 0
At the Market Equity Offering [Member]
At the Market Equity Offering [Abstract]
Issuance of shares to be held as treasury shares | shares	2,393,160	5,000,000	5,000,000
Nominal value per share (in CHF per share) | SFr / shares	SFr 0.02	SFr 0.02
Shares authorized for sale		SFr 74,600	$ 80
Issuance costs | SFr				SFr 0		SFr 0	SFr 500
New Sales Agreement [Member]
At the Market Equity Offering [Abstract]
Number of treasury share issued (in shares) | shares				1,179,139	1,179,139
Proceeds from issuance of treasury shares, net of underwriting fees and transaction costs				SFr 12,100	$ 13.3
Commissions paid				SFr 400	$ 0.4

Share capital - Convertible not

Share capital - Convertible note agreement (Details) $ in Millions	12 Months Ended
	Dec. 31, 2022 CHF (SFr) agreement	Dec. 31, 2022 USD ($)	Dec. 31, 2021 CHF (SFr) shares	Dec. 31, 2021 USD ($) shares	Dec. 31, 2020 CHF (SFr)	Dec. 31, 2022 USD ($) agreement
Convertible Note Agreement [Abstract]
Net proceeds | SFr	SFr 0		SFr 23,463,000		SFr 0
Convertible note agreements
Convertible Note Agreement [Abstract]
Number of separate convertible note agreements | agreement	2					2
Aggregate principal amount of each convertible note	SFr 11,700,000					$ 12.5
Proceeds from conversion of convertible debt, per individual note			SFr 11,700,000	$ 12.5
Number of shares issued through conversion of convertible notes			3,026,634	3,026,634
Outstanding equity or cash consideration due under convertible note agreements | SFr			SFr 0
Convertible note agreements | Athos Service GmbH [Member]
Convertible Note Agreement [Abstract]
Number of shares issued through conversion of convertible notes			1,513,317	1,513,317
Convertible note agreements | First Capital Partner GmbH [Member]
Convertible Note Agreement [Abstract]
Number of shares issued through conversion of convertible notes			1,513,317	1,513,317
Convertible note agreements | Top of Range [Member] | If notes are converted
Convertible Note Agreement [Abstract]
Net proceeds	SFr 23,500,000	$ 25

Trade and other payables and _3

Trade and other payables and accrued expenses (Details) - CHF (SFr) SFr in Thousands	Dec. 31, 2022	Dec. 31, 2021
Trade and other payables and accrued liabilities [Line Items]
Trade and other payables	SFr 929	SFr 2,003
Accrued research and development costs	5,360	10,361
Accrued payroll expenses	2,898	3,562
Other accrued expenses	1,159	2,813
Total	9,417	16,736
Accruals for performance related remuneration	2,100	2,300
Accrual of performance-related remuneration	SFr 2,898	3,562
Accrued stamp duty		800
Janssen
Trade and other payables and accrued liabilities [Line Items]
Accrued research and development costs		SFr 3,700

Contract revenues, Contract Rev

Contract revenues, Contract Revenue Attributable to Licensing Arrangements (Details) - CHF (SFr) SFr in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Contract Revenue [Abstract]
Total contract revenues	SFr 3,935	SFr 0	SFr 15,431
Lilly [Member]
Contract Revenue [Abstract]
Total contract revenues	0	SFr 0	14,348
Percentage of contract revenues		93%
Janssen
Contract Revenue [Abstract]
Total contract revenues	0	SFr 0	1,083
Life Molecular Imaging [Member]
Contract Revenue [Abstract]
Total contract revenues	SFr 3,935	SFr 0	SFr 0
Percentage of contract revenues	100%

Contract revenues and other ope

Contract revenues and other operating income - Licensing and collaboration agreement (Details) - CHF (SFr) SFr in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Disclosure of disaggregation of revenue from contracts with customers [line items]
Amounts included in the contract liability at the beginning of the period	SFr 0		SFr 4,477
Performance obligations satisfied in previous periods	3,935		10,000
Contract revenue	3,935	SFr 0	15,431
License and collaboration agreement of 2014, Life Molecular Imaging [Member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Contract revenue	SFr 3,935	SFr 0	SFr 0

Contract revenues, Morphomer Ta

Contract revenues, Morphomer Tau small molecule - 2018 license agreement with Eli Lilly and Company (Details) SFr in Thousands			3 Months Ended		12 Months Ended			42 Months Ended	47 Months Ended
	Mar. 31, 2020 CHF (SFr) installment	Jan. 23, 2019 CHF (SFr)	Sep. 30, 2019 CHF (SFr) installment	Mar. 31, 2019 CHF (SFr)	Dec. 31, 2022 CHF (SFr) item	Dec. 31, 2021 CHF (SFr)	Dec. 31, 2020 CHF (SFr)	Dec. 31, 2022 CHF (SFr)	Dec. 31, 2022 CHF (SFr)
Contract revenues
Revenue from contracts with customers					SFr 3,935	SFr 0	SFr 15,431
Deferred income					587	717		SFr 587	SFr 587
2018 License Agreement with Eli Lilly and Company [Member]
Contract revenues
Revenue from contracts with customers					SFr 0	0	14,348
Morphomer Tau Small Molecule [Member] | 2018 License Agreement with Eli Lilly and Company [Member]
Contract revenues
Milestone payment received				SFr 80,000
Period to provide notice of termination of agreement					3 months
Number of representatives in joint steering committee by each party | item					3
Revenue from contracts with customers					SFr 0	SFr 0	SFr 14,300
Deferred income					0			0	0
Morphomer Tau Small Molecule [Member] | 2018 License Agreement with Eli Lilly and Company [Member] | Clinical and Regulatory [Member]
Contract revenues
Expected transaction price allocation					880,000			880,000	880,000
Morphomer Tau Small Molecule [Member] | 2018 License Agreement with Eli Lilly and Company [Member] | Commercial [Member]
Contract revenues
Expected transaction price allocation					SFr 900,000			900,000	900,000
Morphomer Tau Small Molecule [Member] | 2018 License Agreement with Eli Lilly and Company [Member] | Research and Development [Member]
Contract revenues
Deferred research and development costs		SFr 6,900
Revenue from contracts with customers									SFr 6,900
Morphomer Tau Small Molecule [Member] | 2018 License Agreement with Eli Lilly and Company [Member] | Right-of-use License [Member]
Contract revenues
Revenue from contracts with customers		SFr 73,100						SFr 40,000
Morphomer Tau Small Molecule [Member] | 2018 License Agreement with Eli Lilly, First Amendment [Member]
Contract revenues
Total potential collaboration agreement value			SFr 60,000
Number of installments | installment			2
Morphomer Tau Small Molecule [Member] | 2018 License Agreement with Eli Lilly, First Amendment [Member] | Quarter 3, 2019
Contract revenues
Milestone payment receivable			SFr 30,000
Morphomer Tau Small Molecule [Member] | 2018 License Agreement with Eli Lilly, First Amendment [Member] | March 31, 2020
Contract revenues
Milestone payment receivable	SFr 30,000		SFr 30,000
Morphomer Tau Small Molecule [Member] | 2018 License Agreement with Eli Lilly, Second Amendment [Member]
Contract revenues
Number of installments | installment	2
Morphomer Tau Small Molecule [Member] | 2018 License Agreement with Eli Lilly, Second Amendment [Member] | March 31, 2020
Contract revenues
Milestone payment receivable	SFr 10,000
Morphomer Tau Small Molecule [Member] | 2018 License Agreement with Eli Lilly, Second Amendment [Member] | Upon first patient dosed in a Phase 2 clinical study of a licensed product in the U.S. or EU.
Contract revenues
Milestone payment receivable	SFr 60,000

Contract revenues, Anti-Abeta A

Contract revenues, Anti-Abeta Antibody in AD - 2006 Agreement with Genentech (Details) SFr in Thousands, $ in Millions	12 Months Ended			36 Months Ended	194 Months Ended
	Dec. 31, 2022 CHF (SFr)	Dec. 31, 2021 CHF (SFr)	Dec. 31, 2020 CHF (SFr)	Dec. 31, 2022 USD ($)	Dec. 31, 2022 CHF (SFr) payment	Dec. 31, 2022 USD ($) payment	Dec. 31, 2022 USD ($)	Mar. 31, 2017 CHF (SFr)	Mar. 31, 2017 USD ($)
Contract revenues
Revenue from contracts with customers | SFr	SFr 3,935	SFr 0	SFr 15,431
Anti-Abeta Antibody in AD [Member] | 2006 Agreement with Genentech [Member]
Contract revenues
Period to provide notice of termination of agreement	3 months
Cumulative payments received	SFr 70,100				SFr 70,100		$ 65
Milestone payment received					SFr 38,200	$ 40
Up-front consideration received								SFr 31,600	$ 25
Number of milestone payments received | payment					3	3
Revenue from contracts with customers | $				$ 0
Collaborative agreement, upfront payments received					SFr 31,600	$ 25
Collaborative agreement, Notice of contract termination period in case of material breach of contract	90 days
Anti-Abeta Antibody in AD [Member] | 2006 Agreement with Genentech [Member] | Clinical milestones achieved prior to 1 January 2017
Contract revenues
Milestone payment received					38,200	$ 40
Anti-Abeta Antibody in AD [Member] | 2006 Agreement with Genentech [Member] | Minimum
Contract revenues
Total potential collaboration agreement value	SFr 317,000				317,000		340
Total potential collaboration agreement value remaining	SFr 256,400				SFr 256,400		$ 275

Contract revenues, Anti-Tau Ant

Contract revenues, Anti-Tau Antibody in AD - 2012 Agreement with Genentech (Details) SFr in Thousands	1 Months Ended	3 Months Ended		12 Months Ended				36 Months Ended	127 Months Ended
	Jul. 31, 2016 CHF (SFr)	Dec. 31, 2017 CHF (SFr)	Jun. 30, 2016 CHF (SFr)	Dec. 31, 2022 CHF (SFr)	Dec. 31, 2021 CHF (SFr)	Dec. 31, 2020 CHF (SFr)	Dec. 31, 2015 CHF (SFr)	Dec. 31, 2022 CHF (SFr)	Dec. 31, 2022 CHF (SFr) payment	Jun. 30, 2012 CHF (SFr)
Contract revenues
Revenue from contracts with customers				SFr 3,935	SFr 0	SFr 15,431
Anti-tau Antibody in AD [Member] | 2012 Agreement with Genentech [Member]
Contract revenues
Period to provide notice of termination of agreement				3 months
Cumulative payments received				SFr 59,000				SFr 59,000	SFr 59,000
Milestone payment received	SFr 14,000	SFr 14,000					SFr 14,000		SFr 42,000
Up-front consideration received										SFr 17,000
Number of milestone payments received | payment									3
Revenue from contracts with customers		SFr 14,000	SFr 14,000					0
Collaborative agreement, Notice of contract termination period in case of material breach of contract				90 days
Anti-tau Antibody in AD [Member] | 2012 Agreement with Genentech [Member] | Minimum
Contract revenues
Total potential collaboration agreement value										SFr 400,000
Anti-tau Antibody in AD [Member] | 2012 Agreement with Genentech [Member] | Maximum
Contract revenues
Total potential collaboration agreement value remaining				SFr 368,500				SFr 368,500	SFr 368,500

Contract revenues, Tau Vaccine

Contract revenues, Tau Vaccine in AD - 2014 Agreement with Janssen Pharmaceuticals (Details) - CHF (SFr) SFr in Thousands	1 Months Ended				12 Months Ended
	Dec. 31, 2022	May 31, 2016	Dec. 31, 2014	May 31, 2014	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Contract revenues
Revenue from contracts with customers					SFr 3,935	SFr 0	SFr 15,431
2014 Agreement with Janssen Pharmaceuticals [Member]
Contract revenues
Revenue from contracts with customers					SFr 0	0	1,083
Tau Vaccine in AD [Member] | 2014 Agreement with Janssen Pharmaceuticals [Member]
Contract revenues
Period to provide notice of termination of agreement					90 days
Milestone payment received		SFr 4,900
Revenue from contracts with customers			SFr 25,900	SFr 4,900	SFr 0	SFr 0	SFr 1,100
Collaborative agreement, upfront payments received	SFr 25,900
Tau Vaccine in AD [Member] | 2014 Agreement with Janssen Pharmaceuticals [Member] | Minimum
Contract revenues
Total potential collaboration agreement value remaining	458,000				458,000
Tau Vaccine in AD [Member] | 2014 Agreement with Janssen Pharmaceuticals [Member] | Maximum
Contract revenues
Total potential collaboration agreement value	SFr 500,000				SFr 500,000

Contract revenues, Tau-PET imag

Contract revenues, Tau-PET imaging agent -2014 Agreement with Life Molecular Imaging (formerly Piramal Imaging SA) (Details) € in Thousands, SFr in Thousands

3 Months Ended

12 Months Ended

Dec. 31, 2015 CHF (SFr)

Dec. 31, 2015 EUR (€)

Sep. 30, 2022 CHF (SFr)

Sep. 30, 2022 EUR (€)

Sep. 30, 2019 CHF (SFr)

Sep. 30, 2019 EUR (€)

Mar. 31, 2017 CHF (SFr)

Mar. 31, 2017 EUR (€)

Dec. 31, 2022 CHF (SFr)

Dec. 31, 2021 CHF (SFr)

Dec. 31, 2020 CHF (SFr)

Dec. 31, 2022 EUR (€)

May 31, 2014 CHF (SFr)

May 31, 2014 EUR (€)

Contract revenues

Revenue from contracts with customers

SFr 3,935

SFr 0

SFr 15,431

2014 Agreement with Life Molecular Imaging (formerly Piramal Imaging SA) [Member]

Contract revenues

Revenue from contracts with customers

SFr 3,935

0

0

Tau-PET Imaging Agent [Member] | 2014 Agreement with Life Molecular Imaging (formerly Piramal Imaging SA) [Member]

Contract revenues

Period to provide notice of termination of agreement

3 months

Revenue from contracts with customers

SFr 664

€ 500

SFr 3,900

€ 4,000

SFr 2,200

€ 2,000

SFr 3,900

SFr 0

SFr 0

Collaborative agreement, Milestone payment received

SFr 1,100

€ 1,000

Tau-PET Imaging Agent [Member] | 2014 Agreement with Life Molecular Imaging (formerly Piramal Imaging SA) [Member] | Clinical milestones

Contract revenues

Total potential collaboration agreement value remaining

4,000

€ 4,000

Tau-PET Imaging Agent [Member] | 2014 Agreement with Life Molecular Imaging (formerly Piramal Imaging SA) [Member] | Regulatory and sales-based milestones

Contract revenues

Total potential collaboration agreement value remaining

SFr 138,000

€ 148,000

Tau-PET Imaging Agent [Member] | 2014 Agreement with Life Molecular Imaging (formerly Piramal Imaging SA) [Member] | Top of Range [Member]

Contract revenues

Total potential collaboration agreement value

SFr 159,000

€ 160,000

Contract revenues - Grants from

Contract revenues - Grants from the Michael J. Fox Foundation (Details) SFr in Thousands, $ in Millions	1 Months Ended		12 Months Ended
	Aug. 31, 2022 CHF (SFr)	Aug. 31, 2022 USD ($)	Dec. 31, 2022 CHF (SFr) item	Dec. 31, 2021 CHF (SFr)	Dec. 31, 2020 CHF (SFr)	Aug. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	May 31, 2020 CHF (SFr)	May 31, 2020 USD ($)
Contract revenues
Revenue from contracts with customers			SFr 3,935	SFr 0	SFr 15,431
Income from grants			1,343	1,182	1,353
Accrued income			408	975
Deferred income			587	717
Grant from Michael J. Fox Foundation
Contract revenues
Revenue from contracts with customers			1,200	1,100	SFr 1,300
Accrued income			300	900
Deferred income			SFr 500
Grant from Michael J. Fox Foundation | Alpha-synuclein PET imaging diagnostic agent
Contract revenues
Follow-on grant funding received, total for joint arrangement	SFr 500	$ 0.5
Follow-on grant funding received	400	$ 0.4
Total potential collaboration agreement value								SFr 3,000	$ 3.2
Eligible grant amount receivable								2,300	2.5
Grant from Michael J. Fox Foundation | Alpha-synuclein PET imaging diagnostic agent | Skane University Hospital
Contract revenues
Eligible grant amount receivable	SFr 100					$ 0.1		SFr 700	0.7
Grant from Michael J. Fox Foundation | Alpha-synuclein PET imaging diagnostic agent | Minimum
Contract revenues
Period of joint research agreement			2 years
Grant from Michael J. Fox Foundation | Advance small molecule PD programs
Contract revenues
Number of grants received | item			2
Total potential collaboration agreement value				SFr 1,400			$ 1.5
Grant from Michael J. Fox Foundation | Skane University Hospital
Contract revenues
Eligible grant amount receivable | $									$ 0.7

Expenses by category (Details)

Expenses by category (Details) SFr in Thousands	12 Months Ended
	Dec. 31, 2022 CHF (SFr) employee	Dec. 31, 2021 CHF (SFr) employee	Dec. 31, 2020 CHF (SFr) employee
Disclosure of detailed information about borrowings [line items]
Operating expenses	SFr 74,782	SFr 79,010	SFr 76,691
Research and development expenses	60,336	62,282	59,487
General and administrative expenses	15,789	17,910	18,557
Financial result, net [Abstract]
Financial income	69	6,485	78
Financial expense	(355)	(581)	(184)
Exchange differences	393	113	(555)
Finance result, net	107	6,017	(661)
Gains on conversion features related to convertible notes		6,500
Research and development expenses
Disclosure of detailed information about borrowings [line items]
Operating expenses	41,166	44,289	43,787
Payroll expenses	17,548	16,465	14,424
Share-based compensation	1,622	1,528	1,276
Total expenses by category	SFr 60,336	SFr 62,282	SFr 59,487
Average number of employees | employee	122.4	108.6	115.3
General and administrative expenses
Disclosure of detailed information about borrowings [line items]
Operating expenses	SFr 6,207	SFr 7,031	SFr 7,471
Payroll expenses	7,874	8,281	8,274
Share-based compensation	1,708	2,598	2,812
Total expenses by category	SFr 15,789	SFr 17,910	SFr 18,557
Average number of employees | employee	22.5	27.3	26.7

Related-party transactions (Det

Related-party transactions (Details) SFr in Thousands	12 Months Ended
	Dec. 31, 2022 CHF (SFr) person	Dec. 31, 2021 CHF (SFr) person	Dec. 31, 2020 CHF (SFr) person
Related-party transactions [Abstract]
Number of individuals, Board of Directors | person	8	8	7
Number of individuals, Executive Management | person	7	6	5
Short-term employee benefits	SFr 4,187	SFr 4,403	SFr 3,497
Post-employment benefits	295	266	214
Share-based compensation	2,503	2,997	2,578
Total compensation	SFr 6,985	SFr 7,666	SFr 6,289

Income taxes - Summary of Incom

Income taxes - Summary of Income Tax Expense (Details) - CHF (SFr) SFr in Thousands	12 Months Ended			24 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Income tax expense	SFr (13)	SFr (3)	SFr 0
Deferred tax assets	0
Deferred tax liabilities	0
Applicable tax rate			13.60%	13.60%
Income tax expense reconciled to Income / (loss) [Abstract]
Loss before income tax	(70,740)	(72,993)	SFr (61,921)
Tax benefit calculated at the domestic rates applicable in the respective countries	(9,616)	(9,930)	(8,441)
(Income not subject to tax)/expenses not deductible for tax purposes	455	(375)	462
Effect of unused tax losses and tax offsets not recognized as deferred tax assets	9,174	10,308	7,979
Effective income tax rate (benefit)/expense	SFr 13	SFr 3	SFr 0
SWITZERLAND
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Applicable tax rate	13.60%			13.60%
Minimum
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Applicable tax rate	13.60%	13.60%
Weighted average
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Applicable tax rate	13.60%			13.60%
Maximum
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Income tax expense	SFr (100)	SFr (100)
Applicable tax rate	33.80%	32.90%
Income tax expense reconciled to Income / (loss) [Abstract]
Effective income tax rate (benefit)/expense	SFr 100	SFr 100

Income taxes, Unrecognized Dedu

Income taxes, Unrecognized Deductible Temporary Differences, Unused Tax Losses and Unused Tax Credits (Details) - CHF (SFr) SFr in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Unrecognized deductible temporary differences, unused tax losses and unused tax credits [Abstract]
Deductible temporary differences for which no deferred tax asset is recognised	SFr 267,302	SFr 204,250	SFr 129,412
Tax losses split by expiry date [Abstract]
Unrecorded tax loss carryforwards	264,089	197,153	121,949
Increase (decrease) in tax losses available for offset against future taxable profits	66,900
December 31, 2024
Tax losses split by expiry date [Abstract]
Unrecorded tax loss carryforwards	15,231	15,231	15,231
December 31, 2025
Tax losses split by expiry date [Abstract]
Unrecorded tax loss carryforwards	48,894	48,894	48,894
December 31, 2026
Tax losses split by expiry date [Abstract]
Unrecorded tax loss carryforwards	0	0	0
December 31, 2027
Tax losses split by expiry date [Abstract]
Unrecorded tax loss carryforwards	57,824	57,824	57,824
December 31, 2028
Tax losses split by expiry date [Abstract]
Unrecorded tax loss carryforwards	75,204	75,204	0
December 31, 2029
Tax losses split by expiry date [Abstract]
Unrecorded tax loss carryforwards	66,936	0	0
Tax Losses
Unrecognized deductible temporary differences, unused tax losses and unused tax credits [Abstract]
Deductible temporary differences for which no deferred tax asset is recognised	264,089	197,152	121,948
Right of use assets and lease liabilities, net
Unrecognized deductible temporary differences, unused tax losses and unused tax credits [Abstract]
Deductible temporary differences for which no deferred tax asset is recognised	0	0	0
Retirement benefit plan
Unrecognized deductible temporary differences, unused tax losses and unused tax credits [Abstract]
Deductible temporary differences for which no deferred tax asset is recognised	SFr 3,213	SFr 7,098	SFr 7,464

Retirement benefit plan - Summa

Retirement benefit plan - Summary of Benefit Plan (Details) - CHF (SFr) SFr in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Disclosure of net defined benefit liability (asset) [line items]
Defined benefit plans, percentage of contributions by employees	47%
Defined benefit plans, percentage of contributions by employer	53%
Defined Benefit Obligation [Member]
Defined benefit pension plan amount recognized in balance sheet [Abstract]
Defined benefit obligation	SFr (32,410)	SFr (33,889)	SFr (30,213)
Fair value of plan assets	29,197	26,791	22,749
Total liability	SFr (3,213)	SFr (7,098)	SFr (7,464)

Retirement benefit plan - Amoun

Retirement benefit plan - Amounts recorded in consolidated statements of income (loss) (Details) - CHF (SFr) SFr in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Retirement benefit plan
Service cost	SFr 1,712	SFr 1,648	SFr 1,626
Interest cost	126	79	71
Interest income	(87)	(48)	(42)
Net pension cost	SFr 1,751	SFr 1,679	SFr 1,655

Retirement benefit plan, Change

Retirement benefit plan, Changes in Defined Benefit Obligation (Details) - CHF (SFr) SFr in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Changes in defined benefit obligation [Abstract]
At beginning of period	SFr (7,098)	SFr (7,464)	SFr (7,485)
At end of period	(3,213)	(7,098)	(7,464)
Defined Benefit Obligation [Member]
Changes in defined benefit obligation [Abstract]
At beginning of period	(33,889)	(30,213)	(26,624)
Service cost	(1,712)	(1,648)	(1,626)
Interest cost	(126)	(79)	(71)
Change in demographic assumptions	29	0	1,428
Change in financial assumptions	8,397	156	(71)
Change in experience assumptions	(1,726)	(252)	(931)
Benefits deposited	(2,327)	(894)	(1,467)
Employees' contributions	(1,056)	(959)	(851)
At end of period	SFr (32,410)	SFr (33,889)	SFr (30,213)

Retirement benefit plan, Chan_2

Retirement benefit plan, Changes in Fair Value of Plan Assets (Details) - CHF (SFr) SFr in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Changes in fair value of plan assets [Abstract]
At beginning of period	SFr (7,098)	SFr (7,464)	SFr (7,485)
Employer's contributions	1,210	1,089	950
At end of period	(3,213)	(7,098)	(7,464)
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	1,200
Fair Value of Plan Assets [Member]
Changes in fair value of plan assets [Abstract]
At beginning of period	26,791	22,749	19,139
Interest income	87	48	42
Employees' contributions	1,056	959	851
Employer's contributions	1,210	1,089	950
Benefits deposited	2,327	894	1,467
Return on plan assets excluding interest income	(2,274)	1,052	300
At end of period	SFr 29,197	SFr 26,791	SFr 22,749

Retirement benefit plan, Chan_3

Retirement benefit plan, Change in Net Defined Benefit Liability (Details) - CHF (SFr) SFr in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Change in net defined benefit liability [Abstract]
Net defined benefit liabilities, beginning of period	SFr 7,098	SFr 7,464	SFr 7,485
Net pension cost through statement of income/(loss)	1,751	1,679	1,655
Remeasurement through other comprehensive income/(loss)	(4,426)	(956)	(726)
Employer's contribution	(1,210)	(1,089)	(950)
Net defined benefit liabilities, end of period	SFr 3,213	SFr 7,098	SFr 7,464

Retirement benefit plan - Chang

Retirement benefit plan - Change in other comprehensive gains (losses) (Details) - CHF (SFr) SFr in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Other comprehensive gains/(losses) [Abstract]
Effect of changes in demographic assumptions	SFr 29	SFr 0	SFr 1,428
Effect of changes in financial assumptions	8,397	156	(71)
Effect of changes in experience assumptions	(1,726)	(252)	(931)
Return on plan assets excluding interest income	(2,274)	1,052	300
Total other comprehensive gain	SFr 4,426	SFr 956	SFr 726
Weighted average duration period for defined benefit obligation	14 years 10 months 24 days	17 years 1 month 6 days

Retirement benefit plan, Actuar

Retirement benefit plan, Actuarial Assumptions and Sensitivity Analysis (Details) - CHF (SFr) SFr in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Actuarial assumptions [Abstract]
Discount rate	2.25%	0.30%	0.20%
Rate of future increase in compensations	1.75%	1.75%	1.75%
Rate of future increase in current pensions	0%	0%	0%
Interest rate on retirement savings capital	2.25%	0.75%	0.50%
+0.5% Increase [Member]
Sensitivity analysis [Abstract]
Percentage increase in actuarial assumption	0.50%	0.50%
-0.5% Decrease [Member]
Sensitivity analysis [Abstract]
Percentage decrease in actuarial assumption	0.50%	0.50%
Discount rate | +0.5% Increase [Member]
Sensitivity analysis [Abstract]
Percentage increase in actuarial assumption	0.50%	0.50%
Potential defined benefit obligation	SFr 30,201	SFr 31,190
Decrease/(increase) from actual defined benefit obligation	SFr (2,209)	SFr (2,699)
Discount rate | -0.5% Decrease [Member]
Sensitivity analysis [Abstract]
Percentage decrease in actuarial assumption	0.50%	0.50%
Potential defined benefit obligation	SFr 34,916	SFr 37,006
Decrease/(increase) from actual defined benefit obligation	SFr 2,506	SFr 3,117
Future salary increase | +0.5% Increase [Member]
Sensitivity analysis [Abstract]
Percentage increase in actuarial assumption	0.50%	0.50%
Potential defined benefit obligation	SFr 32,940	SFr 34,578
Decrease/(increase) from actual defined benefit obligation	SFr 530	SFr 689
Future salary increase | -0.5% Decrease [Member]
Sensitivity analysis [Abstract]
Percentage decrease in actuarial assumption	0.50%	0.50%
Potential defined benefit obligation	SFr 31,841	SFr 33,176
Decrease/(increase) from actual defined benefit obligation	SFr (569)	SFr (713)
Future pension cost | +0.5% Increase [Member]
Sensitivity analysis [Abstract]
Percentage increase in actuarial assumption	0.50%	0.50%
Potential defined benefit obligation	SFr 33,601	SFr 35,497
Decrease/(increase) from actual defined benefit obligation	SFr 1,191	SFr 1,608
Future pension cost | -0.5% Decrease [Member]
Sensitivity analysis [Abstract]
Percentage decrease in actuarial assumption	0.50%	0.50%
Potential defined benefit obligation	SFr 31,322	SFr 32,435
Decrease/(increase) from actual defined benefit obligation	SFr (1,088)	SFr (1,454)
Interest rate on savings capital | +0.5% Increase [Member]
Sensitivity analysis [Abstract]
Percentage increase in actuarial assumption	0.50%	0.50%
Potential defined benefit obligation	SFr 33,322	SFr 34,822
Decrease/(increase) from actual defined benefit obligation	SFr 912	SFr 933
Interest rate on savings capital | -0.5% Decrease [Member]
Sensitivity analysis [Abstract]
Percentage decrease in actuarial assumption	0.50%	0.50%
Potential defined benefit obligation	SFr 31,545	SFr 33,007
Decrease/(increase) from actual defined benefit obligation	SFr (865)	SFr (882)

Share-based compensation, Plans

Share-based compensation, Plans Outstanding (Details)	12 Months Ended			74 Months Ended
	Dec. 31, 2022 Options plan	Dec. 31, 2021 Options	Dec. 31, 2020 Options	Dec. 31, 2022 Options
Share-based compensation [Abstract]
Number of equity-based instrument plans | plan	2
Share-based plans outstanding [Abstract]
Number of options awarded (in shares)	1,090,316	1,110,914	1,073,027
Share 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 SOIP [Member] | Executives and Directors [Member]
Share-based plans outstanding [Abstract]
Number of options awarded (in shares)				3,277,044
Contractual life of options	10 years
2016 SOIP [Member] | Employees [Member]
Share-based plans outstanding [Abstract]
Number of options awarded (in shares)				1,811,687
Vesting conditions	4 years
Contractual life of options	10 years
2016 SOIP, Vesting Condition 1 [Member] | Executives and Directors [Member]
Share-based plans outstanding [Abstract]
Vesting conditions	1 year
2016 SOIP, Vesting Condition 2 [Member] | Executives and Directors [Member]
Share-based plans outstanding [Abstract]
Vesting conditions	3 years
2016 SOIP, Vesting Condition 3 [Member] | Executives and Directors [Member]
Share-based plans outstanding [Abstract]
Vesting conditions	4 years

Share-based compensation, Weigh

Share-based compensation, Weighted Average Exercise Prices (Details)	12 Months Ended
	Dec. 31, 2022 Options SFr / shares	Dec. 31, 2022 Options $ / shares SFr / shares	Dec. 31, 2021 Options SFr / shares	Dec. 31, 2021 Options SFr / shares $ / shares	Dec. 31, 2020 Options SFr / shares	Dec. 31, 2020 Options $ / shares SFr / shares	Dec. 31, 2019 Options SFr / shares
Number of options [Abstract]
Outstanding at beginning of period (in shares)	3,585,689	3,585,689	2,900,667	2,900,667	1,981,629	1,981,629
Forfeited during the year (in shares)	(304,738)	(304,738)	(207,331)	(207,331)	(53,591)	(53,591)
Expired during the year (in shares)					(26,729)	(26,729)
Exercised during the year (in shares)	(110,250)	(110,250)	(218,561)	(218,561)	(73,669)	(73,669)
Granted during the year (in shares)	1,090,316	1,090,316	1,110,914	1,110,914	1,073,027	1,073,027
Outstanding at end of period (in shares)	4,261,017	4,261,017	3,585,689	3,585,689	2,900,667	2,900,667	1,981,629
Exercisable (in shares)	2,345,648	2,345,648	1,613,242	1,613,242	1,099,015	1,099,015
Weighted average exercise price [Abstract]
Outstanding at beginning of period (in CHF per share) | SFr / shares	SFr 6.21		SFr 5.90		SFr 5.93
Forfeited during the year (in CHF per share) | SFr / shares	6.32		6.13		6.03
Expired during the year (in CHF per share) | SFr / shares					4.38
Exercised during the year (in CHF per share) | SFr / shares	0.15		4.97		2
Granted during the year (in CHF per share) | (per share)	3.18	$ 3.44	6.34	$ 6.95	6.29	$ 7.11
Outstanding at end of period (in CHF per share) | SFr / shares	5.65		6.21		5.90		SFr 5.93
Exercisable (in CHF per share) | SFr / shares	SFr 6.41	$ 6.41	SFr 6.13	$ 6.13	SFr 5.49	$ 5.49
Weighted average remaining term (years) [Abstract]
Weighted average remaining term (years), options outstanding	7 years 7 months 6 days	7 years 7 months 6 days	7 years 9 months 18 days	7 years 9 months 18 days	8 years 2 months 12 days	8 years 2 months 12 days	8 years 3 months 18 days
Weighted average remaining term (years), options exercisable	6 years 7 months 6 days	6 years 7 months 6 days	6 years 9 months 18 days	6 years 9 months 18 days	7 years	7 years

Share-based compensation, Outst

Share-based compensation, Outstanding Options, Range of Exercise prices and Expiration Dates (Details)	12 Months Ended
	Dec. 31, 2022 Options SFr / shares	Dec. 31, 2022 Options $ / shares	Dec. 31, 2021 Options SFr / shares	Dec. 31, 2021 Options $ / shares	Dec. 31, 2020 Options SFr / shares	Dec. 31, 2020 Options $ / shares	Dec. 31, 2019 Options
Outstanding options, exercise price range and expiry dates [Abstract]
Outstanding Options (in shares)	4,261,017	4,261,017	3,585,689	3,585,689	2,900,667	2,900,667	1,981,629
Weighted average exercise price for options granted (in CHF/USD per share) | (per share)	SFr 3.18	$ 3.44	SFr 6.34	$ 6.95	SFr 6.29	$ 7.11
Weighted average share price of common share options exercised (in dollars per share) | (per share)	3.28	3.55
Minimum
Outstanding options, exercise price range and expiry dates [Abstract]
Weighted average exercise price for options granted (in CHF/USD per share) | (per share)	0.15	2.76
Top of Range [Member]
Outstanding options, exercise price range and expiry dates [Abstract]
Weighted average exercise price for options granted (in CHF/USD per share) | (per share)	SFr 9.53	$ 12.30
CHF 0.15
Outstanding options, exercise price range and expiry dates [Abstract]
Outstanding Options (in shares)	97,875	97,875
CHF 9.53
Outstanding options, exercise price range and expiry dates [Abstract]
Outstanding Options (in shares)	223,646	223,646
USD 5.04 to USD 12.30
Outstanding options, exercise price range and expiry dates [Abstract]
Outstanding Options (in shares)	2,864,408	2,864,408
USD 2.76 to USD 4.57
Outstanding options, exercise price range and expiry dates [Abstract]
Outstanding Options (in shares)	1,075,088	1,075,088

Share-based compensation, Wei_2

Share-based compensation, Weighted Average Grant date Fair Value and Assumptions (Details)	12 Months Ended
	Dec. 31, 2022 USD ($) Y $ / shares	Dec. 31, 2021 USD ($) Y $ / shares	Dec. 31, 2020 USD ($) Y $ / shares	Dec. 31, 2022 CHF (SFr)	Dec. 31, 2021 CHF (SFr)	Dec. 31, 2020 CHF (SFr)
Number and weighted average exercise prices of options under the share option programs [Abstract]
Weighted average fair value at measurement date, share options granted	$ 2.38	$ 5.23	$ 5.25	SFr 2.20	SFr 4.78	SFr 4.65
Weighted average assumptions [Abstract]
Share price (weighted average)	$ 3.44	$ 6.95	$ 7.11
Risk free interest rate		0%	0%
Expected volatility		80%	80%
Dividend yield	0%	0%	0%
Minimum
Weighted average assumptions [Abstract]
Exercise price (in USD per share)	$ 2.76	$ 5.31	$ 5.04
Risk free interest rate	0%
Expected volatility	67%
Expected term | Y	5.5	5.1	5.5
Top of Range [Member]
Weighted average assumptions [Abstract]
Exercise price (in USD per share)	$ 4.57	$ 7.72	$ 9.16
Risk free interest rate	2.40%
Expected volatility	80%
Expected term | Y	6.25	6	6

Share-based compensation, Non-v

Share-based compensation, Non-vested Share Awards (Details)	12 Months Ended			74 Months Ended
	Dec. 31, 2022 CHF (SFr) EquityInstruments	Dec. 31, 2021 CHF (SFr) EquityInstruments	Dec. 31, 2020 CHF (SFr) EquityInstruments	Dec. 31, 2022 CHF (SFr) EquityInstruments
Weighted Average grant date fair value [Abstract]
Expense charged against the income statement | SFr	SFr 3,300,000	SFr 4,100,000	SFr 4,100,000
Directors [Member]
Share-based payment arrangement [Abstract]
Vesting conditions	1 year
Non-vested Share Awards [Member]
Share-based payment arrangement [Abstract]
Number of non-vested share awards granted (in shares)	239,194		0
Number of non-vested shares [Abstract]
Non-vested at beginning of period (in shares)	797	19,494	42,763
Forfeited during the year (in shares)			(11,828)
Expired during the year (in shares)			(7,804)
Exercised during the year (in shares)		(2,471)	(84,638)
Granted during the year (in shares)	239,194		0
Vested during the year	(23,505)	(18,697)	(23,269)
Non-vested at end of period (in shares)	216,486	797	19,494	216,486
Vested and exercisable (in shares)	89,020	65,515	49,289	89,020
Weighted Average grant date fair value [Abstract]
Weighted average grant date fair value, non-vested at beginning of period | SFr	SFr 9.41	SFr 9.51	SFr 9.52
Weighted average grant date fair value, forfeited during the year | SFr			9.47
Weighted average grant date fair value, expired during the year | SFr			9.52
Weighted average grant date fair value, exercised during the year | SFr		9.46	9.51
Weighted average grant date fair value, granted during the year | SFr	3.06		0
Weighted average grant date fair value, vested during the year | SFr	3.28	9.52	9.52
Weighted average grant date fair value, vested and exercisable | SFr	7.84	9.48	9.47	SFr 7.84
Weighted average grant date fair value, non-vested at end of period | SFr	3.06	9.41	9.51	3.06
Restricted Stock Units
Weighted Average grant date fair value [Abstract]
Weighted average grant date fair value, non-vested at beginning of period | SFr	9.41	9.51
Weighted average grant date fair value, non-vested at end of period | SFr	SFr 3.06	SFr 9.41	SFr 9.51	SFr 3.06
Restricted Stock Units | Directors [Member]
Share-based payment arrangement [Abstract]
Number of non-vested share awards granted (in shares)				159,025
Contractual life of options	10 years
Number of non-vested shares [Abstract]
Granted during the year (in shares)				159,025
Restricted Stock Units | Executives [Member]
Share-based payment arrangement [Abstract]
Number of non-vested share awards granted (in shares)				274,872
Contractual life of options	10 years
Number of non-vested shares [Abstract]
Granted during the year (in shares)				274,872
Restricted Stock Units, first vesting conditions | Executives [Member]
Share-based payment arrangement [Abstract]
Vesting conditions	3 years
Restricted Stock Units, second vesting conditions | Executives [Member]
Share-based payment arrangement [Abstract]
Vesting conditions	4 years

Commitments and contingencies_2

Commitments and contingencies (Details) - CHF (SFr) SFr in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Commitments and contingencies [Abstract]
Notice period for cancellation of rental contract	12 months
Contractual capital commitments	SFr 52,488	SFr 23,699
Within 1 Year
Commitments and contingencies [Abstract]
Contractual capital commitments other than for leases	23,000
Contractual capital commitments	23,336	19,785
1-3 years
Commitments and contingencies [Abstract]
Contractual capital commitments	18,516	3,620
3-5 years
Commitments and contingencies [Abstract]
Contractual capital commitments	9,229	243
More Than 5 Years [Member]
Commitments and contingencies [Abstract]
Contractual capital commitments	SFr 1,407	SFr 51

Earnings per share (Details)

Earnings per share (Details) - CHF (SFr) SFr / shares in Units, SFr in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Numerator
Net loss attributable to equity holders of the Company	SFr (70,753)	SFr (72,996)	SFr (61,921)
Denominator
Weighted-average number of shares outstanding used to compute EPS basic attributable to equity holders	83,554,412	74,951,833	71,900,212
Weighted-average number of shares outstanding used to compute EPS diluted attributable to equity holders	83,554,412	74,951,833	71,900,212
Basic loss per share for the period attributable to equity holders	SFr (0.85)	SFr (0.97)	SFr (0.86)
Diluted loss per share for the period attributable to equity holders	SFr (0.85)	SFr (0.97)	SFr (0.86)
Antidilutive securities
Share options issued and outstanding (in-the-money)	135,827	1,140,388	412,191
Restricted share awards subject to future vesting	117,292	6,264	28,418
Convertible shares	0	41,461	0
Total potentially dilutive securities	253,119	1,188,113	440,609

Financial instruments and ris_3

Financial instruments and risk management (Details) SFr in Thousands	12 Months Ended
	Dec. 31, 2022 CHF (SFr) Institution	Dec. 31, 2021 CHF (SFr)	Dec. 31, 2020 CHF (SFr)
Financial assets and liabilities [Abstract]
Financial assets	SFr 126,147	SFr 201,921
Financial liabilities	13,147	21,649
Financial risks [Abstract]
Foreign exchange gains (losses)	393	113	SFr (555)
Long-term lease liabilities
Financial assets and liabilities [Abstract]
Financial liabilities	2,253	2,340
Trade and other payables
Financial assets and liabilities [Abstract]
Financial liabilities	929	2,003
Accrued expenses
Financial assets and liabilities [Abstract]
Financial liabilities	9,417	16,736
Short-term lease liabilities
Financial assets and liabilities [Abstract]
Financial liabilities	548	570
Right-of-use assets
Financial assets and liabilities [Abstract]
Financial assets	2,808	2,914
Long-term financial assets
Financial assets and liabilities [Abstract]
Financial assets	361	363
Other current receivables [Member]
Financial assets and liabilities [Abstract]
Financial assets	392	428
Short-term financial assets
Financial assets and liabilities [Abstract]
Financial assets	91,000	116,000
Cash and cash equivalents
Financial assets and liabilities [Abstract]
Financial assets	31,586	82,216
Foreign Currency Exchange Risk [Member]
Financial risks [Abstract]
Foreign exchange gains (losses)	SFr 500	(100)	SFr (700)
Percentage of reasonably possible strengthening or weakening of reporting currency against other relevant currencies	10%
Increase (decrease) in profit (loss) resulting from reasonably possible strengthening or weakening of reporting currency against other relevant currencies	SFr 700	SFr 1,700
Credit Risk [Member]
Financial risks [Abstract]
Number of financial institutions holding cash and cash equivalents and short-term financial assets | Institution	5
Liquidity Risk [Member]
Financial risks [Abstract]
Cash position rolling forecast period	18 months
Liquidity Risk [Member] | Trade and other payables
Financial assets and liabilities [Abstract]
Financial liabilities	SFr 900
Liquidity Risk [Member] | Accrued expenses
Financial assets and liabilities [Abstract]
Financial liabilities	9,400
Interest Rate [member]
Financial risks [Abstract]
Cash and cash equivalents subject to negative interest rates	SFr 0
Percentage of reasonably possible increase or decrease in interest rates	10%
Interest Rate [member] | Top of Range [Member]
Financial risks [Abstract]
Increase (decrease) in profit (loss) resulting from reasonably possible increase or decrease in interest rates	SFr 200