0001558370-23-003778 | 10-K | XBRL Viewer

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Document and Entity Information - USD ($) $ in Millions	12 Months Ended
Document and Entity Information - USD ($) $ in Millions	Dec. 31, 2022	Mar. 07, 2023	Jun. 30, 2022
Document Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2022
Document Transition Report	false
Entity File Number	001-38869
Entity Registrant Name	HOOKIPA PHARMA INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	81-5395687
Entity Address, Address Line One	350 Fifth Avenue, 72nd Floor, Suite 7240
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10118
Country Region	+43
City Area Code	1
Local Phone Number	890 63 60
Title of 12(b) Security	Common Stock, $0.0001 Par Value per Share
Trading Symbol	HOOK
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Public Float			$ 82.6
Auditor Name	PwC Wirtschaftsprüfung GmbH
Auditor Firm ID	1259
Auditor Location	Vienna, Austria
Entity Central Index Key	0001760542
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Amendment Flag	false
Common stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		52,322,822
Class A common stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		2,399,517

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 112,488	$ 65,921
Restricted cash	537	566
Accounts receivable	6,533	6,895
Receivable research incentives	15,479	14,271
Prepaid expenses and other current assets	12,159	14,482
Total current assets	147,196	102,135
Non-current assets:
Restricted cash	419	425
Property, plant and equipment, net	17,970	16,352
Operating lease right of use assets	4,006	5,673
Finance lease right of use assets		90
Other non-current assets	863	1,370
Total non-current assets	23,258	23,910
Total assets	170,454	126,045
Current liabilities
Accounts payable	5,488	8,762
Deferred revenues	15,684	5,538
Operating lease liabilities, current	1,688	1,682
Accrued expenses and other current liabilities	11,178	8,880
Loans payable, current	1,594	2,792
Total current liabilities	35,632	27,654
Non-current liabilities
Loans payable, non-current	911	2,219
Operating lease liabilities, non-current	2,310	3,911
Deferred revenues, non-current	25,664	21
Other non-current liabilities	3,420	2,648
Total non-current liabilities	32,305	8,799
Total liabilities	67,937	36,453
Commitments and contingencies (Note 13)
Stockholders' equity:
Preferred stock, $0.0001 par value; 10,000,000 shares authorized at December 31, 2022 and December 31, 2021, respectively; Series A convertible preferred stock, 2,978 shares designated, 1,697 shares outstanding at December 31, 2022 and December 31, 2021, respectively; Series A-1 convertible preferred stock, 15,800 shares and no shares designated, 15,800 shares and no shares outstanding at December 31, 2022 and December 31, 2021, respectively	0	0
Additional paid-in capital	397,349	317,135
Accumulated other comprehensive loss	(7,156)	(4,780)
Accumulated deficit	(287,681)	(222,766)
Total stockholders' equity	102,517	89,592
Total liabilities and stockholders' equity	170,454	126,045
Common stock
Stockholders' equity:
Common stock	5	3
Class A common stock
Stockholders' equity:
Common stock	$ 0	$ 0

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2022	Dec. 31, 2021
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	10,000,000
Series A Convertible Preferred Stock
Preferred stock shares Designated	2,978	2,978
Preferred stock, shares outstanding	1,697	1,697
Series A -1 Convertible Preferred Stock
Preferred stock shares Designated	15,800	0
Preferred stock, shares outstanding	15,800	0
Common stock
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	200,000,000	100,000,000
Common stock, shares issued	52,317,138	27,383,483
Common stock, shares outstanding	52,317,138	27,383,483
Class A common stock
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	3,900,000	3,900,000
Common stock, shares issued	2,399,517	3,819,732
Common stock, shares outstanding	2,399,517	3,819,732

CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS
Revenue from collaboration and licensing	$ 14,249	$ 18,448	$ 19,584
Revenue from Contract with Customer, Product and Service [Extensible List]	hook:CollaborationAndLicensingMember	hook:CollaborationAndLicensingMember	hook:CollaborationAndLicensingMember
Operating expenses:
Research and development	$ (68,645)	$ (82,853)	$ (54,787)
General and administrative	(18,759)	(17,269)	(18,082)
Total operating expenses	(87,404)	(100,122)	(72,869)
Loss from operations	(73,155)	(81,674)	(53,285)
Other income (expense):
Grant income	7,916	9,724	6,517
Interest income	1,633	27	400
Interest expense	(687)	(898)	(786)
Other income and (expenses), net	(392)	(2,843)	3,072
Total other income, net	8,470	6,010	9,203
Net loss before tax	(64,685)	(75,664)	(44,082)
Income tax expense	(230)	(1)	0
Net loss	(64,915)	(75,665)	(44,082)
Other comprehensive (loss) income:
Foreign currency translation gain (loss), net of tax	(2,376)	1,287	(1,414)
Comprehensive loss	$ (67,291)	$ (74,378)	$ (45,496)
Net loss per share - basic	$ (0.99)	$ (2.30)	$ (1.69)
Net loss per share - diluted	$ (0.99)	$ (2.30)	$ (1.69)

CONSOLIDATED STATEMENTS OF CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) - USD ($) $ in Thousands	Convertible Preferred Stock Series A Convertible Preferred Stock	Convertible Preferred Stock Series A-1 convertible preferred stock	Convertible Preferred Stock	Common Stock Common stock Public offering	Common Stock Common stock Stock Purchase Agreement	Common Stock Common stock	Common Stock Class A common stock	Common Stock Series A Convertible Preferred Stock	Additional Paid-In Capital Series A Convertible Preferred Stock	Additional Paid-In Capital Series A-1 convertible preferred stock	Additional Paid-In Capital Public offering	Additional Paid-In Capital Stock Purchase Agreement	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit	Series A Convertible Preferred Stock	Series A-1 convertible preferred stock	Public offering	Stock Purchase Agreement	Total
Balance at the beginning of the period at Dec. 31, 2019						$ 3	$ 0						$ 225,568	$ (4,653)	$ (103,019)					$ 117,899
Balance at the beginning of the period (in shares) at Dec. 31, 2019						21,746,392	3,819,732
Increase (Decrease) in Stockholders' Equity
Issuance of common stock	$ 0			$ 0					$ 32,426		$ 42,574					$ 32,426		$ 42,574
Issuance of common stock (in shares)	2,978			3,910,000
Issuance of common stock upon exercise of stock options						$ 0							63							63
Issuance of common stock upon exercise of stock options (in shares)						255,011
Vesting of restricted stock						$ 0							0
Vesting of restricted stock (in shares)						1,060
Vesting of equity grants						$ 0							0
Vesting of equity grants (in shares)						36,249
Foreign currency translation (loss)/gain														(1,414)						(1,414)
Stock-based compensation expense													8,657							8,657
Net loss															(44,082)					(44,082)
Balance at the end of the period at Dec. 31, 2020			$ 0			$ 3	$ 0						309,288	(6,067)	(147,101)					156,123
Balance at the end of the period (in shares) at Dec. 31, 2020			2,978			25,948,712	3,819,732
Increase (Decrease) in Stockholders' Equity
Conversion of preferred stock into common stock	$ 0							$ 0	$ 0
Conversion of preferred stock into common stock (in shares)	(1,281)							1,281,000
Issuance of common stock upon exercise of stock options						$ 0							203							203
Issuance of common stock upon exercise of stock options (in shares)						110,071
Vesting of restricted stock						$ 0							0
Vesting of restricted stock (in shares)						43,700
Foreign currency translation (loss)/gain														1,287						1,287
Stock-based compensation expense													7,644							7,644
Net loss															(75,665)					(75,665)
Balance at the end of the period at Dec. 31, 2021			$ 0			$ 3	$ 0						317,135	(4,780)	(222,766)					89,592
Balance at the end of the period (in shares) at Dec. 31, 2021			1,697			27,383,483	3,819,732
Increase (Decrease) in Stockholders' Equity
Issuance of common stock		$ 0		$ 2	$ 0					$ 29,625	$ 40,685	$ 5,000					$ 29,625	$ 40,687	$ 5,000
Issuance of common stock (in shares)		15,800		21,700,000	1,666,666
Conversion of Class A common stock to common stock						$ 0	$ 0
Conversion of Class A common stock to common stock (in shares)						1,420,215	(1,420,215)
Issuance of common stock upon exercise of stock options						$ 0							3							$ 3
Issuance of common stock upon exercise of stock options (in shares)						34,223														34,223
Vesting of restricted stock						$ 0							0
Vesting of restricted stock (in shares)						112,551
ATM costs													(142)							$ (142)
Foreign currency translation (loss)/gain														(2,376)						(2,376)
Stock-based compensation expense													5,043							5,043
Net loss															(64,915)					(64,915)
Balance at the end of the period at Dec. 31, 2022			$ 0			$ 5	$ 0						$ 397,349	$ (7,156)	$ (287,681)					$ 102,517
Balance at the end of the period (in shares) at Dec. 31, 2022			17,497			52,317,138	2,399,517

CONSOLIDATED STATEMENTS OF CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2020
Series A Convertible Preferred Stock
Share price (in USD per share)		$ 11,750
Issuance costs		$ 2,565
Series A-1 convertible preferred stock
Share price (in USD per share)	$ 2,000
Issuance costs	$ 1,975
Common stock \| Public offering
Share price (in USD per share)	$ 2.00	$ 11.75
Issuance costs	$ 2,713	$ 3,368
Common stock \| Stock Purchase Agreement
Share price (in USD per share)	$ 3.00
Issuance costs	$ 0

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating activities:
Net loss	$ (64,915)	$ (75,665)	$ (44,082)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	5,043	7,644	8,657
Depreciation and amortization expense	3,602	4,640	4,150
Other non-cash items	160	1,226	53
Changes in operating assets and liabilities:
Accounts receivable	(341)	(1,943)	(3,576)
Receivable research incentives	(1,958)	(295)	(5,825)
Prepaid expenses and other current assets	2,007	(7,091)	(2,286)
Other non-current assets	424	416	(1,080)
Accounts payable	(1,999)	858	6,298
Deferred revenues	35,508	1,422	511
Operating lease liabilities	(1,584)	(1,588)	(1,833)
Accrued expenses and other liabilities	2,510	4,776	(184)
Other non-current liabilities	1,546	(416)	(142)
Net cash used in operating activities	(19,997)	(66,016)	(39,339)
Investing activities:
Purchases of property and equipment	(5,017)	(12,581)	(2,371)
Net cash used in investing activities	(5,017)	(12,581)	(2,371)
Financing activities:
Payments related to finance leases	(25)	(438)	(108)
Proceeds from issuance of convertible preferred stock, net of issuance costs	29,625		32,426
Proceeds from issuance of common stock, net of issuance costs	45,691	203	42,637
Payments for deferred offering costs	(195)		(224)
Repayments of borrowings	(2,825)	0	(1,311)
Net cash provided by (used in) financing activities	72,271	(235)	73,420
Net increase (decrease) in cash, cash equivalents and restricted cash	47,257	(78,832)	31,710
Cash, cash equivalents and restricted cash at beginning of period	66,912	143,177	113,575
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(725)	2,567	(2,108)
Cash, cash equivalents and restricted cash at end of period	113,444	66,912	143,177
Supplemental disclosure of cash flow information:
Cash paid for interest	(32)	(48)	(97)
Cash paid for income taxes	(1)	(1)	0
Supplemental disclosure of non-cash financing activities:
Property and equipment additions in accounts payable and accrued expenses	(56)	(742)	16
Lease assets obtained in exchange for new operating lease liabilities	$ 225	2,727	12
Lease assets derecognized upon lease cancellation		$ 1,061	$ 30

Nature of the business and organization

12 Months Ended

Dec. 31, 2022

Nature of the business and organization

Nature of the business and organization

1. Nature of the business and organization

HOOKIPA Pharma Inc. (“HOOKIPA” or the “Company”) is a clinical stage biopharmaceutical company developing a new class of immunotherapeutics based on its proprietary arenavirus platform that is designed to reprogram the body’s immune system.

The Company was incorporated under the name of Hookipa Biotech, Inc. under the laws of the State of Delaware in February 2017 as a fully-owned subsidiary of Hookipa Biotech AG. In June 2018, the Company changed its name from Hookipa Biotech, Inc. to HOOKIPA Pharma Inc. and in order to effectuate the change of the jurisdiction of incorporation, the Company acquired all of the shares of Hookipa Biotech AG, now Hookipa Biotech GmbH. HOOKIPA is headquartered in New York, with European research and preclinical development operations headquartered in Vienna, Austria. In April 2019, the Company closed its initial public offering (“IPO”) and its common stock started trading on the Nasdaq Global Select Market under the ticker symbol “HOOK”.

The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry, including, but not limited to, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, compliance with government regulations, the ability to establish clinical- and commercial-scale manufacturing processes and the ability to secure additional capital to fund operations. Product candidates currently under development will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities and may not ultimately lead to a marketing approval and commercialization of a product. Even if the Company’s drug development efforts are successful, it is uncertain if and when the Company will realize significant revenue from product sales.

Summary of significant accounting policies

12 Months Ended

Dec. 31, 2022

Summary of significant accounting policies

Summary of significant accounting policies

2. Summary of significant accounting policies

Basis of presentation

The Company’s consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). The accompanying consolidated financial statements include the accounts of the Company and its wholly owned subsidiary. All intercompany accounts and transactions have been eliminated in consolidation.

Going concern

Since inception, the Company’s activities have consisted primarily of performing research and development to advance its technologies. The Company is still in the development phase and has not been marketing its technologies to date. Through December 31, 2022, the Company has funded its operations with proceeds from sales of common stock, sales of convertible preferred stock, sales of redeemable convertible preferred stock, collaboration and licensing agreements, grants and borrowings under various agreements with foreign public funding agencies. Since inception, the Company has incurred recurring losses, including net losses of $64.9 million, $75.7 million and $44.1 million for the years ended December 31, 2022, 2021 and 2020, respectively. As of December 31, 2022, the Company had an accumulated deficit of $287.7 million. The Company expects to continue to generate operating losses in the foreseeable future. As of March 15, 2023, the filing date of this Annual Report on Form 10-K, the Company expects that its cash and cash equivalents, together with the funds received under the Restated Gilead Collaboration Agreement and the funds received under the Roche Collaboration Agreement, both described below, would be sufficient to fund its operating expenses, capital expenditure requirements and debt service payments through at least 12 months from the issuance date of the consolidated financial statements.

The Company will seek additional funding in order to reach its development and commercialization objectives. The Company may seek funds through further equity financings, debt financings, collaborations, strategic alliances and marketing, distribution or licensing arrangements. The Company may not be able to obtain financing on acceptable terms, or at all, and the Company may not be able to enter into collaborations or other arrangements. The terms of any financing may adversely affect the holdings or the rights of the Company’s stockholders. If the Company is unable to obtain funding, the Company could be forced to delay, reduce or eliminate some or all of its research and development programs, product portfolio expansion or commercialization efforts, which could adversely affect its business prospects.

The accompanying consolidated financial statements have been prepared assuming that the Company will continue as a going concern, which contemplates the realization of assets and the settlement of liabilities and commitments in the normal course of business. The consolidated financial statements do not reflect any adjustments relating to the recoverability and classification of assets or the amounts and classification of liabilities that might be necessary if the Company is unable to continue as a going concern.

Use of estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue, income and expenses during the reporting periods. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, the recognition of revenue and income, the accrual of research and development expenses and general and administrative expenses, the present value of lease right of use assets and corresponding liabilities, the valuation of stock-based awards and the valuation of current and non-current loans payable. The Company bases its estimates on historical experience, known trends and other market-specific or other relevant factors that it believes to be reasonable under the circumstances. On an ongoing basis, management evaluates its estimates as there are changes in circumstances, facts and experience.

The COVID-19 pandemic continues to affect economies and business around the world. The extent and duration of such effects remain uncertain and difficult to predict, particularly as virus variants continue to spread. The Company is actively monitoring and managing its response and assessing actual and potential impacts to its operating results and financial condition, as well as developments in its business, which could further impact the developments, trends and expectations described below. As of the date of issuance of these consolidated financial statements, the Company is not aware of any specific event or circumstance that would require the Company to update estimates, judgments or revise the carrying value of any assets or liabilities. Actual results may differ from those estimates or assumptions.

Foreign currency and currency translation

The functional currency for the Company is the United States dollar and the functional currency for the Company's wholly owned foreign subsidiary, Hookipa Biotech GmbH, is the euro.

Assets and liabilities of Hookipa Biotech GmbH are translated into United States dollars at the exchange rate in effect on the balance sheet date. Income items and expenses are translated at the average exchange rate in effect during the period. Unrealized translation gains and losses are recorded as a cumulative translation adjustment, which is included in the Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) as a component of Accumulated other comprehensive loss. Adjustments that arise from exchange rate changes on transactions denominated in a currency other than the local currency are included in other income and expenses, net in the Consolidated Statements of Operations and Comprehensive Loss as incurred.

Concentrations of credit risk and of significant suppliers

Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash, cash equivalents and short-term bank deposits held with banks in excess of publicly insured limits. For the years ended December 31, 2022 and December 31, 2021 the net proceeds from the Company’s offerings have been deposited in interest-bearing bank accounts with two of the largest investment grade U.S. financial institutions and have been partially invested in money market funds. The money market funds, held in U.S. dollars, are primarily invested in U.S. and foreign short-term debt obligations. As of December 31, 2022 and December 31, 2021, the Company’s cash and cash equivalents included smaller amounts of cash balances held in accounts with regional European banks at the Company’s Austrian subsidiary, partially in euros. The Company does not believe that it is subject to unusual credit risk beyond the normal credit risk associated with commercial banking relationships.

The Company relies, and expects to continue to rely, on a small number of vendors to manufacture supplies and raw materials for its development programs. These programs could be adversely affected by a significant interruption in these manufacturing services or the availability of raw materials.

As of December 31, 2022 and December 31, 2021, respectively, Gilead Sciences, Inc. (“Gilead”) accounted for the majority of the accounts receivable balance. For the years ended December 31, 2022, December 31, 2021 and December 31, 2020 Gilead accounted for the majority of the Company’s revenues. No other customers accounted for more than 10.0% of accounts receivable or net sales. In the year ended December 31, 2022, the Company recorded significant deferred revenues under an agreement with F. Hoffmann-La Roche Ltd. and Hoffmann-La Roche Inc. (together “Roche”) representing more than 10.0% of the Company’s revenues from customers, when recognized. The Company monitors the financial performance of its customers so that it can appropriately respond to changes in their credit worthiness. To date, the Company has not experienced any significant losses with respect to collection of its accounts receivable.

Cash equivalents

The Company considers all highly liquid investments with maturities of three months or less at the date of purchase to be cash equivalents. As of December 31, 2022 and December 31, 2021 cash equivalents consisted of money market funds and short-term deposits.

Deferred offering costs

The Company capitalizes certain legal, professional accounting and other third-party fees that are directly associated with in-process equity financings as deferred offering costs until such financings are consummated. After consummation of an equity financing, these costs are recorded in stockholders’ equity as a reduction of the additional paid-in capital on a pro-rata basis generated as a result of the offering. Should the in-process equity financing be abandoned, the deferred offering costs will be expensed immediately as a charge to operating expenses in the consolidated statements of operations and comprehensive loss.

Fair value measurements

Certain assets and liabilities are carried at fair value under GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three

levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable:

●

Level 1 - Quoted prices in active markets for identical assets or liabilities.

●

Level 2 - Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data.

●

Level 3 - Unobservable inputs that are supported by little or no market activity and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques.

The Company’s cash equivalents are carried at fair value, determined according to the fair value hierarchy described above (see Note 4).

Property and equipment

Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation and amortization expense is recognized using the straight-line method over the estimated useful life of each asset as follows:


		Estimated useful life
Leasehold improvements		shorter of useful life or term of lease
Laboratory equipment		2 - 10 years
Furniture and fixtures		2 - 10 years
Computer equipment and software		2 - 4 years

Costs for capital assets not yet placed into service are capitalized as construction-in-progress and depreciated once placed into service. Expenditures for repairs and maintenance are charged to expense as incurred. When property and equipment is sold or otherwise disposed of, the cost and related accumulated depreciation are eliminated from the accounts and any resulting gain or loss is reflected in the consolidated statements of operations.

Leases

The determination whether an arrangement qualifies as a lease is made at contract inception. A lease qualifies as a finance lease if any of the following criteria are met at the inception of the lease: (i) there is a transfer of ownership of the leased asset to the Company by the end of the lease term, (ii) the Company holds an option to purchase the leased asset that it is reasonably certain to exercise, (iii) the lease term is for a major part of the remaining economic life of the leased asset, (iv) the present value of the sum of lease payments equals or exceeds substantially all of the fair value of the leased asset, or (v) the nature of the leased asset is specialized to the point that it is expected to provide the lessor no alternative use at the end of the lease term. All other leases are recorded as operating leases and are included in right of use (“ROU”) assets and lease liabilities in the consolidated balance sheets. For leases with an initial term of 12 months or less, the Company does not recognize a right of use asset or lease liability. These short-term leases are expensed on a straight-line basis over the lease term.

ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent its obligation to make lease payments arising from the lease. ROU assets and lease liabilities are recognized at the commencement date of the lease based upon the present value of lease payments over the lease term. When

determining the lease term, the Company includes options to extend or terminate the lease when it is reasonably certain that the option will be exercised. The Company uses the implicit rate when readily determinable and uses its incremental borrowing rate when the implicit rate is not readily determinable based upon the information available at the commencement date in determining the present value of the lease payments. The incremental borrowing rate is determined using a secured borrowing rate for the same currency and term as the associated lease. The lease payments used to determine ROU assets may include lease incentives, stated rent increases and escalation clauses linked to rates of inflation when determinable and are recognized as ROU asset on the consolidated balance sheet. In addition, certain of the Company’s arrangements contain lease and non-lease components. The Company generally separates lease payments from non-lease payments. Operating leases are reflected in operating lease assets, in current operating lease liabilities and non-current operating lease liabilities in the consolidated balance sheets. Finance leases are reflected in finance lease assets, in accrued expenses and other current liabilities and in other non-current operating lease liabilities in the consolidated balance sheets. The ROU asset is tested for impairment in accordance with Accounting Standards Codification (“ASC”) 360.

Capitalized Software Development Cost

The Company capitalizes certain implementation costs for internal-use software incurred in a cloud computing agreement that is a service contract. Eligible costs associated with cloud computing arrangements, such as software business applications used in the normal course of business, are capitalized in accordance with ASC 350. These costs are recognized on a straight-line basis in the same line item in the statement of operations and comprehensive loss as the expense for fees for the associated cloud computing arrangement, over the term of the arrangement, plus reasonably certain renewals. Amortization expense of $0.1 million associated with the Company's cloud computing arrangements has been recognized during the fiscal year ended December 31, 2022. Amortization expense of less than $0.1 million associated with the Company's cloud computing arrangements has been recognized during the fiscal year ended December 31, 2021 (see Note 5). The Company tests for impairment whenever events or changes in circumstances indicate that the carrying amount may not be recoverable.

Impairment of long-lived assets

Long-lived assets, including operating and finance lease right of use assets, consist of property and equipment. Long-lived assets to be held and used are tested for recoverability whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. Factors that the Company considers in deciding when to perform an impairment review include significant underperformance of the business in relation to expectations, significant negative technological, scientific or economic trends and significant changes or planned changes in the use of the assets.

If an impairment review is performed to evaluate a long-lived asset group for recoverability, the Company compares forecasts of undiscounted cash flows expected to result from the use and eventual disposition of the long-lived asset group to its carrying value. An impairment loss would be recognized in loss from operations when estimated undiscounted future cash flows expected to result from the use of an asset group are less than its carrying amount. The impairment loss would be based on the excess of the carrying value of the impaired asset group over its fair value, determined based on discounted cash flows. The Company did not record any impairment losses on long-lived assets during the years ended December 31, 2022, 2021 and 2020.

Segment information

The Company manages its operations as a single segment for the purposes of assessing performance and making operating decisions. The Company's singular focus is on developing pharmaceutical products to prevent and cure infectious diseases and cancer. The Chief Executive Officer is the chief operating decision maker, and regularly reviews

the consolidated operating results to make decisions about the allocation of the Company's resources. The majority of the Company's tangible assets are held in Austria.

Revenue recognition from contracts with customers

The Company recognized revenue from collaboration and license agreements with Gilead and Roche.

Under the collaboration and license agreement with Gilead (as amended and restated, the “Gilead Collaboration Agreement”), the parties agreed to collaborate with respect to two preclinical research programs to evaluate potential vaccine products for the treatment, cure, diagnosis or prevention of the hepatitis B virus (“HBV”) and the human immunodeficiency virus (“HIV”). In February 2022, the parties signed an amended and restated collaboration agreement (the “Restated Gilead Collaboration Agreement”), which revised the terms only for the HIV program, whereby the Company will take on development responsibilities for the HIV program candidate through a Phase 1b clinical trial. The Company’s performance obligations under the terms of the original agreement include one combined performance obligation for each research program (HBV and HIV) comprised of the transfer of intellectual property rights (licenses) and providing research and development services. The terms of the Restated Gilead Collaboration Agreement added an additional performance obligation to perform research and development work for the HIV program. The licenses do not represent distinct performance obligations, because they cannot be used without the research and development services. Payments to the Company under the Restated Gilead Collaboration Agreement include a non-refundable up-front payment, payments for research and development activities, payments based upon the achievement of defined milestones, and if certain future conditions are met, payments for manufacturing services, commercial milestones and royalties on product sales.

Under the research collaboration and license agreement with Roche (the “Roche Collaboration Agreement”), the Company will conduct research and early clinical development through Phase 1b for HB-700, a novel investigational arenaviral immunotherapy for the treatment of KRAS-mutated cancers. The Roche Collaboration Agreement also includes an obligation of the Company to deliver a specified package of preclinical data and results with respect to a second program, targeting undisclosed cancer antigens (collectively “UCAs”) and an option for Roche to license the UCA program. The Company’s performance obligations under the terms of the Roche Collaboration Agreement include one combined performance obligation for the transfer of intellectual property rights (licenses) and providing research and development services for the HB-700 program, and a second, separate performance obligation to perform research and development services with respect to the UCA program. The UCA option provides a right to license the program at the standalone selling price and therefore does not constitute a separate performance obligation. Payments to the Company under the Roche Collaboration Agreement include a non-refundable up-front payment, payments based upon the achievement of defined milestones, an additional payment if the option for the UCA program is exercised and royalties on product sales.

The Company evaluates its collaboration and licensing arrangements pursuant to ASC 606 Revenue from Contracts with Customers. To determine the recognition of revenue from arrangements that fall within the scope of ASC 606, the Company performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the Company satisfies a performance obligation.

Under ASC 606, the Company applies significant judgement to evaluate whether the promises under the collaboration and licensing arrangements, represent separate or one or more combined performance obligations, the allocation of the transaction price to identified performance obligations, the timing of revenue recognition, whether the UCA Option constitutes a material right, and the determination of when milestone payments are probable of being received.

Upfront payment and program initiation fee

The non-refundable upfront-payment received by the Company upon signing of the Gilead Collaboration Agreement, and milestone payments that were linked to future performance obligations, were initially recorded as deferred revenue and allocated between the two research program performance obligations. Such amounts are recognized as revenue over the performance period of the respective services on a percent of completion basis using total estimated research and development labor hours (input method) for each of the obligations. The percent of completion basis using labor hours was considered the best measure of progress in which control of the combined performance obligations transfers to the customer, due to the short time intervals in which research results are shared with the collaboration partner and the nature of the work being performed.

The non-refundable program initiation payment received from Gilead upon signing of the Restated Collaboration Agreement was also initially recorded as deferred revenue and is recognized on a percent of completion basis using total estimated research and development costs (input method) for the performance of the obligations. The percent of completion basis using research and development costs was considered the best measure of progress in which control of the performance obligations transfers to the customer, due to the immediate benefit that it adds to the value of the customer’s rights on the program, the short time intervals in which development results are shared and the nature of the work being performed.

The non-refundable upfront-payment received by the Company upon signing of the Roche Collaboration Agreement, was initially recorded as deferred revenue and allocated between the HB-700 program and the UCA program. Such amounts are recognized as revenue over the performance period of the respective services on a percent of completion basis using total estimated research and development costs (input method) for each of the obligations during the initial term of the contract. The percent of completion basis using research and development costs was considered the best measure of progress in which control of the performance obligations transfers to the customer.

Reimbursement for services

Under the Gilead Collaboration Agreement and the Roche Collaboration Agreement, the Company incurs employee expenses as well as external costs for research, manufacturing and clinical trial activities presented as operating expenses or prepaid expenses. Based on the nature of the Company's responsibilities under the collaboration arrangements, reimbursement of those costs are presented as revenue and not deducted from expenses, as the Company controls the research activities. Amounts of consideration allocated to the performance of research or manufacturing services are recognized over the period in which services are performed. Reimbursements for external costs are recognized as revenues as progress is achieved. Unpaid reimbursement amounts are presented as Accounts receivable.

Research and development milestones

The Gilead Collaboration Agreement and the Roche Collaboration Agreement include contingent milestone payments related to specified preclinical and clinical development milestones. These milestone payments represent variable consideration that are not initially recognized within the transaction price as they are fully constrained under the guidance in ASC 606, due to the scientific uncertainties and the required commitment from Gilead and Roche. The Company will continue to assess the probability of significant reversals for any amounts that become likely to be realized prior to including the variable consideration associated with these payments within the transaction price.

Sales-based milestones and royalty payments

The Gilead Collaboration Agreement and the Roche Collaboration Agreement also include certain sales-based milestone and royalty payments upon successful commercialization of a licensed product. In accordance with ASC 606-10-55-65 Sales Based or Usage Based Royalties, the Company recognizes revenues from sales-based milestone and

royalty payments at the later of (i) the occurrence of the subsequent sale; or (ii) the performance obligation to which some or all of the sales-based milestone or royalty payments has been allocated has been satisfied. The Company anticipates recognizing these milestones and royalty payments if and when subsequent sales are generated from a licensed product by the collaboration partner.

Cost to fulfill contracts

The Company incurs costs for personnel, supplies and other costs related to its laboratory operations as well as fees from third parties and license expenses in connection with its research and development obligations under the collaboration and licensing agreement. These costs are recognized as research and development expenses over the period in which services are performed. Sublicense fees triggered by the receipt of payments are capitalized as an asset when the obligation to pay the fee arises. The capitalized asset is amortized over the period in which the revenue from the triggering payment is recognized.

Research and development costs

Research and development costs are expensed as incurred. Research and development expenses consist of costs incurred in performing research and development activities, including salaries and bonuses, stock-based compensation, employee benefits, facilities costs, laboratory supplies, depreciation, manufacturing expenses and external costs of vendors engaged to conduct preclinical development activities and clinical trials as well as the cost of licensing technology. Advance payments for goods or services to be received in the future for use in research and development activities are recorded as prepaid expenses. The prepaid amounts are expensed as the related goods are delivered or the services are performed.

Upfront payments, milestone payments and annual payments made for the licensing of technology are generally expensed as research and development in the period in which they are incurred. Incremental sublicense fees triggered by contracts with customers are capitalized and expensed as research and development expenses over the period in which the related revenue is recognized.

Research and manufacturing contract costs and accruals

The Company has entered into various research and development and manufacturing contracts. Related payments are recorded as the corresponding expenses are incurred. The Company records accruals for estimated ongoing costs and prepaid expenses for advance payments. When evaluating the adequacy of the accrued liabilities and prepaid expenses, the Company analyzes progress of the research studies or clinical trials and manufacturing activities, including the phase or completion of events, invoices received and contracted costs. Significant judgments and estimates are made in determining the accrued balances at the end of any reporting period. Actual results could differ from the Company's estimates. The Company's historical accrual estimates have not been materially different from the actual costs.

Government grant agreements and research incentives

The Company recognizes funding from grants and research incentives received from Austrian government agencies as other income. Income from grants and incentives is recognized in the period during which the related qualifying expenses are incurred, provided that the conditions under which the grants or incentives were provided have been met. For grants under funding agreements and for proceeds under research incentive programs, the Company recognizes grant and incentive income in an amount equal to the estimated qualifying expenses incurred in each period multiplied by the applicable reimbursement percentage.

Grant funding that has been received by the Company in advance of incurring qualifying expenses is recorded as deferred income. Grant and incentive income recognized upon incurring qualifying expenses in advance of receipt of

grant funding or proceeds from research and development incentives is recorded in the consolidated balance sheets as prepaid expenses and other current assets.

The Company has received loans under funding agreements that bear interest at rates that are below market rates of interest. The Company accounts for the imputed benefit arising from the difference between a market rate of interest and the rate of interest charged as additional grant funding, and records interest expense for the loans at a market rate of interest. On the date that loan proceeds are received, the Company recognizes the portion of the loan proceeds allocated to grant funding as a discount to the carrying value of the loan and as other liability, which is subsequently recognized as additional grant income over the term of the funding agreement.

Stock-based compensation

The Company measures stock-based awards granted to employees and directors based on the fair value on the date of grant using the Black-Scholes option-pricing model for options or the difference between the purchase price per share of the award, if any, and the fair value of the Company's common stock for restricted common stock awards. Compensation expense for those awards is recognized over the requisite service period, which is generally the vesting period of the respective award. The Company uses the graded-vesting method to record the expense of awards with service-based vesting conditions.

The Company classifies stock-based compensation expense in its Consolidated Statements of Operations and Comprehensive Loss in the same manner in which the recipient's payroll costs are classified or in which the recipient's service payments are classified.

Comprehensive loss

Comprehensive loss includes net loss and foreign currency translation adjustments. For the year ended December 31, 2022 comprehensive loss included $2.4 million of foreign currency translation loss adjustments. For the year ended December 31, 2021 comprehensive loss included $1.3 million of foreign currency translation gain adjustments. For the year ended December 31, 2020, comprehensive loss included $1.4 million of foreign currency translation loss adjustments.

Net loss per share

Basic net loss per share is computed by dividing the net loss by the weighted average number of shares of common stock outstanding for the period. Diluted net loss per share is computed by dividing net loss by the weighted average number of shares outstanding for the period, including potential dilutive shares assuming the dilutive effect of outstanding stock options and of convertible preferred stock. For periods in which the Company has reported net losses, diluted net loss per common share is the same as basic net loss per share, since dilutive common shares are not assumed to have been issued if their affect is anti-dilutive.

The Company reported a net loss attributable to common stockholders for the years ended December 31, 2022, 2021 and 2020.

Income taxes

The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the consolidated financial statements or in the Company's tax returns. Under this method, deferred tax assets and liabilities are determined on the basis of the differences between the financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates

on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. Changes in deferred tax assets and liabilities are recorded in income tax expense. The Company assesses the likelihood that its deferred tax assets will be recovered from future taxable income and, to the extent it believes, based upon the weight of available evidence, that it is more likely than not that all or a portion of the deferred tax assets will not be realized, a valuation allowance is established through a charge to income tax expense. Potential for recovery of deferred tax assets is evaluated by estimating the future taxable profits expected and considering prudent and feasible tax planning strategies.

The Company accounts for uncertainty in income taxes recognized in the consolidated financial statements by applying a two-step process to determine the amount of tax benefit to be recognized. First, the tax position must be evaluated to determine the likelihood that it will be sustained upon external examination by the taxing authorities. If the tax position is deemed more-likely-than-not to be sustained, the tax position is then assessed to determine the amount of benefit to recognize in the financial statements. The amount of the benefit that may be recognized is the largest amount that has a greater than 50% likelihood of being realized upon ultimate settlement. The provision for income taxes includes the effects of any resulting tax reserves, or unrecognized tax benefits, that are considered appropriate as well as the related net interest and penalties.

The 2017 Tax Cuts and Jobs Act subjects a US shareholder to tax on global intangible low-taxed income (“GILTI”) earned by certain foreign subsidiaries. The FASB Staff Q&A, Topic 740, No. 5, Accounting for Global Intangible Low-Taxed Income, states that an entity can make an accounting policy election to either recognize deferred taxes for temporary basis differences expected to reverse as GILTI in the future years or provide for tax expense related to GILTI in the year the tax is incurred. The Company has elected to recognize tax expense related to GILTI in the year the tax is incurred.

Recent accounting pronouncements

From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (“FASB”) or other standard setting bodies that the Company adopts as of the specified effective date.

Adopted as of current period

In November 2021, the FASB issued ASU 2021-10, Government Assistance (Topic 832): Disclosures by Business Entities about Government Assistance, which requires business entities to provide certain disclosures when they have received government assistance and when they use a grant or contribution accounting model by analogy to other accounting guidance (e.g., a grant model under IAS 20, Accounting for Government Grants and Disclosure of Government Assistance, or ASC 958-605, Not-For-Profit Entities – Revenue Recognition). Topic 832 requires the annual disclosures about transactions with a government that are accounted for by applying a grant or contribution accounting model by analogy of information about the nature of the transactions and the related accounting policy used to account for the transactions, the line items on the balance sheet and income statement that are affected by the transactions, and the amounts applicable to each financial statement line item, significant terms and conditions of the transactions, including commitments and contingencies. The guidance in ASU 2021-10 is effective for all entities for fiscal years beginning after December 15, 2021. The Company has already provided all relevant disclosures regarding Government Assistance on its consolidated financial statements prior adoption of ASU 2021-10. Therefore, the early adoption of this standard as of January 1, 2022 on a prospective basis did not have a material impact on the Company’s consolidated financial statements.

Recently Issued Accounting Pronouncements

In August 2020, the FASB issued ASU 2020-06, Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging – Contracts in Entity’s Own Equity (Subtopic 815-40). The ASU provides guidance that

simplified the accounting for certain financial instruments with characteristics of liabilities and equity. The new guidance reduced the number of accounting models for convertible debt and convertible preferred stock instruments and made certain disclosure amendments intended to improve the information provided to users. The guidance also amended the derivative guidance for the “own stock” scope exception, which exempts qualifying instruments from being accounted for as derivatives if certain criteria are met. Finally, the standard changed the way certain convertible instruments are treated when calculating earnings per share. This guidance is effective for fiscal years beginning after December 15, 2023, including interim periods within those fiscal years with early adoption permitted. The Company is currently assessing the impact that this guidance will have on its consolidated financial statements.

Collaboration and Licensing Agreements

12 Months Ended

Dec. 31, 2022

Collaboration and Licensing Agreements

Collaboration and Licensing Agreements

3. Collaboration and Licensing Agreements

Gilead Collaboration and License Agreement

In June 2018, the Company entered into the Gilead Collaboration Agreement whereby the Company and Gilead agreed to collaborate with respect to two preclinical research programs to evaluate potential vaccine products for the treatment, cure, diagnosis or prevention of HBV and HIV. In February 2022, the Company signed an Amended and Restated Collaboration Agreement, which altered key aspects of the collaboration pertaining to the HIV therapeutic. Most importantly, the Amended and Restated Collaboration Agreement allocated additional research and development responsibility to the Company with respect to the Company’s HIV candidate and provided for additional funding by Gilead of such research and development activities as well as increased later stage development and commercial milestone payments.

Under the Gilead Collaboration Agreement, the Company granted Gilead an exclusive, royalty-bearing license to the Company’s technology platforms. Upon entering into the agreement in June 2018, the Company received a non-refundable $10.0 million upfront payment from Gilead and upon signing of the Restated Gilead Collaboration Agreement in February 2022, the Company received a program initiation fee of $15.0 million. Gilead is also obligated to make additional payments to the Company upon the achievement of pre-clinical, development and commercial milestones. The development milestones amount to $140.0 million for the HBV program, and up to $172.5 million for the HIV program, inclusive of a $10.0 million program completion fee, payable upon Gilead’s exercise of the option to pursue further development activities post Phase 1b. The commercial milestones amount to a total of $50.0 million for the HBV program, and $65.0 million for the HIV program. Additionally, Gilead is obligated to pay royalties on net sales for each program. Payments from Gilead generally have a 60 day payment term.

The $10.0 million upfront payment, the $15.0 million initiation fee and $8.0 million in milestone payments were initially recorded as deferred revenue in the consolidated balance sheet and are recognized as revenue when revenue recognition criteria are met. As of December 31, 2022, $14.3 million of such payments were still recorded as a liability in deferred revenues, current and non-current. As of December 31, 2021, $4.3 million of upfront and milestone payments were included as a liability in deferred revenues, current. Approximately 29% of deferred revenue is expected to be recognized as revenue in 2023, 34% in 2024, 25% in 2025 and the remaining 12% in 2026.

As of December 31, 2022, no cost reimbursements for research and development services were included as a liability in deferred revenues. As of December 31, 2021, $1.2 million of cost reimbursements for research and development services were included as a liability in deferred revenues. Reimbursements for external costs are recognized as revenues as progress is achieved.

In the year ended December 31, 2022, the Company recognized $3.7 million of the milestone and initiation payments that were originally recorded as deferred revenue. Furthermore, the Company recognized $5.2 million revenue from cost reimbursements for research and development services. In addition, the Company fully recognized revenue for a $5.0 million milestone payment for a milestone achieved in December 2022. In the year ended December 31, 2021, the Company recognized $2.1 million of the upfront and milestone payments that were originally recorded as deferred

revenue. Furthermore, the Company recognized $16.3 million revenue from cost reimbursements for research and development services. No revenue has been recognized for another $4.0 million milestone payment that was recorded as deferred revenue in December 2021. For the year ended December 31, 2020, the Company recognized $4.4 million of the upfront and milestone payments that were originally recorded as deferred revenue. Furthermore, the Company recognized $13.0 million revenue from cost reimbursements for research and development services. In addition, the Company fully recognized revenue for $2.2 million milestone payments for milestones achieved in the year ended December 31, 2020.

Sublicense fees payable to certain licensors of technologies upon the receipt of the deferred upfront and milestone payments, were capitalized as a contract asset and will be amortized over the period in which the revenue from the triggering payment is recognized. As of December 31, 2022, the contract asset relating to the sublicense payment was $0.2 million and there was no liability relating to sublicense payment. As of December 31, 2021, the contract asset and the liability relating to the sublicense payment was $0.3 million, respectively.

Roche Collaboration and License Agreement

In October 2022, the Company entered into the Roche Collaboration Agreement whereby the Company and Roche agreed to collaborate with respect to the development of novel arenaviral immunotherapies for KRAS-mutated cancers and, potentially, a second, novel arenaviral immunotherapeutic program targeting specific undisclosed cancer antigens.

Under the Roche Collaboration Agreement, the Company granted Roche an exclusive, royalty-bearing license to the Company’s technology platforms. Upon signing the Roche Collaboration Agreement in October 2022, the Company received a non-refundable upfront payment of $25.0 million and Roche will be obliged to pay an additional $15.0 million payment if the option for the UCA program is exercised. The Company is also eligible for event-based milestone payments of up to an aggregate of $335.0 million during the research and development phase of the HB-700 program for up to four oncology indications and up to an aggregate of $250.0 million in payments related to the achievement of sales-based milestones. For the additional UCA program, subject to option-exercise, the Company is eligible for up to an aggregate of $173.0 million in event-based milestone payments during research and development for up to four oncology indications as well as up to an aggregate of $160.0 million in sales-based milestones. Upon commercialization, the Company is eligible to receive tiered royalties on the worldwide net sales of HB-700 and, subject to option exercise, the UCA program. The royalty payments are subject to reduction under specified conditions set forth in the Roche Collaboration Agreement. Payments from Roche generally have payment terms between 30 days and 60 days.

The $25.0 million upfront payment was initially recorded as deferred revenue in the consolidated balance sheet and is recognized as revenue when revenue recognition criteria are met. As of December 31, 2022, $27.0 million of the upfront payment was included as a liability in deferred revenues, current and non-current. The deferred revenues related to the $25.0 million upfront payment are subject to foreign currency exchange rate fluctuations in future accounting periods. Approximately 43% of deferred revenue is expected to be recognized as revenue in 2023, 17% in 2024, 16% in 2025, 15% in 2026 and the remaining 9% in 2027.

In the year ended December 31, 2022, the Company recognized $0.3 million of the upfront payment that was originally recorded as deferred revenue.

Sublicense fees payable to certain licensors of technologies upon the receipt of the deferred upfront and milestone payments, were capitalized as a contract asset and will be amortized over the period in which the revenue from the triggering payment is recognized. As of December 31, 2022 the contract asset and the liability relating to the sublicense payment was $1.5 million and $1.2 million, respectively.

Fair Value of Financial Assets

12 Months Ended

Dec. 31, 2022

Fair Value of Financial Assets

Fair Value of Financial Assets

4. Fair Value of Financial Assets

The following tables present information about the Company’s financial assets measured at fair value on a recurring basis and indicating the level of the fair value hierarchy utilized to determine such fair values (in thousands):


	Fair Value Measurement at December 31, 2022 Using
	Level 1		Level 2		Level 3		Total
Cash equivalents:
Money market funds	$	85,491	$	—	$	—	$	85,491
Total	$	85,491	$	—	$	—	$	85,491


	Fair Value Measurement at December 31, 2021 Using
	Level 1		Level 2		Level 3		Total
Cash equivalents:
Money market funds	$	35,403	$	—	$	—	$	35,403
Total	$	35,403	$	—	$	—	$	35,403

During the year ended December 31, 2022, there were no transfers between Level 1, Level 2 and Level 3.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Property, plant and equipment, net

12 Months Ended

Dec. 31, 2022

Property, plant and equipment, net.

Property, plant and equipment, net

5. Property, plant and equipment, net

Property, plant and equipment, net consisted of the following (in thousands):


	December 31,		December 31,
	2022		2021

Land	$	1,959	$	2,072
Leasehold improvements		3,164		3,348
Construction in progress		10,567		7,746
Laboratory equipment		7,403		7,025
Furniture and fixtures		622		651
Computer equipment and software		2,034		1,876
Property and equipment, gross		25,749		22,718
Less: Accumulated depreciation		(7,779)		(6,366)
Property and equipment, net	$	17,970	$	16,352

Depreciation expense for the years ended December 31, 2022, 2021 and 2020 was $1.9 million, $2.1 million and $1.7 million, respectively. Construction-in-progress as of December 31, 2022 and December 31, 2021 mainly related to investments in connection with the Company’s GMP manufacturing facility project.

Receivable research incentive

12 Months Ended

Dec. 31, 2022

Receivable research incentive

Receivable research incentive

6. Receivable research incentive

The Company participates in a research incentive program provided by the Austrian government under which it is entitled to reimbursement of a percentage of qualifying research and development expenses and capital expenditures incurred in Austria. Submissions for reimbursement under the program are submitted annually. Incentive amounts are generally paid out during the calendar year that follows the year of the expenses but remain subject to subsequent examinations by the responsible authority. Reimbursements received in excess of the recognized receivable research incentive for a certain period are recorded within other long term liabilities for potential repayment until such time that an audit has taken place, upon expiration of the potential reclaim period, or when it is no longer probable that a reclaim will happen. The years 2018 to present remain open to examination by the authorities.

As of December 31, 2022, the Company recognized receivables of $15.5 million from the research incentive program, which are reported in research incentive receivables in the Company’s consolidated balance sheet. As of December 31, 2021, the receivables from the research incentive program were $14.3 million.

During the years ended December 31, 2022, 2021 and 2020, the Company recorded $7.3 million, $8.9 million and $5.8 million, respectively, of income related to the incentive program within the Company’s consolidated statements of operations as part of the grant income. Research incentives depend on the eligible research and development expenses of the respective period.

Leases

12 Months Ended

Dec. 31, 2022

Leases

Leases

7. Leases

The Company leases real estate, including office and laboratory space and has entered into various other agreements with respect to assets used in conducting its business. The Company’s leases have remaining lease terms ranging from less than 1 year to 3 years. Some of the lease agreements contain rent holidays and rent escalation clauses that were included in the calculation of the right of use assets and lease liabilities. The Company is required to maintain a cash balance of $0.4 million to secure letters of credit associated with real estate leases. This amount was classified as non-current restricted cash in the consolidated balance sheet as of December 31, 2022.

Certain of the Company’s leases qualify as operating leases, and certain of its leases qualify as finance leases. The following table summarizes the presentation in the consolidated balance sheets (in thousands):


		December 31,		December 31,
	Balance sheet location	2022		2021
Assets
Operating lease assets, net	Operating lease right of use assets	$	4,006	$	5,673
Finance lease assets, net	Finance lease right of use assets		—		90
Total lease assets			4,006		5,763
Liabilities
Current operating lease liability	Operating lease liabilities, current		1,688		1,682
Current finance lease liability	Accrued expenses and other current liabilities		—		21
Total current lease liabilities			1,688		1,703
Non-current operating lease liability	Operating lease liabilities, non-current		2,310		3,911
Non-current finance lease liability	Other non-current liabilities		—		—
Total non-current lease liabilities			2,310		3,911
Total lease liabilities		$	3,998	$	5,614

In the year ended December 31, 2021 the Company terminated leases of parking spaces and derecognized the relating right of use asset and the lease liability which were insignificant.

The following table summarizes the effect of lease costs in the Company’s consolidated statements of operations and comprehensive loss (in thousands):


		Year ended		Year ended		Year ended
	Income statement location	December 31, 2022		December 31, 2021		December 31, 2020
Operating lease expenses	Research and development expenses	$	1,430	$	1,910		1,654
	General and administrative expenses		219		203		376
Finance lease amortization expenses	Research and development expenses		89		425		395
	General and administrative expenses		—		7		21
Interest on finance lease liabilities	Interest expenses		0		5		8
Sublease income	Other income (expense)		—		(40)		(155)
Net lease expense		$	1,738	$	2,510		2,299

The minimum lease payments for the next five years and thereafter are expected to be as follows (in thousands):


	December 31, 2022
	Operating lease
2023		1,570
2024		1,316
2025		1,174
2026		—
2027		—
Thereafter		—
Total lease payments		4,060
Less: interest		62
Present value of lease liabilities	$	3,998

The weighted average remaining lease term and weighted average discount rate of operating leases are as follows:


	December 31,		December 31,
	2022		2021
Weighted average remaining lease term in years	2.8		3.7
Weighted average discount rate ⁽¹⁾	1.3	%	1.3	%

⁽¹⁾ The majority of the contracts are denominated in euros. The discount rate was determined on a currency-equivalent basis.

The weighted average remaining lease term and weighted average discount rate of finance leases are as follows:


	December 31,		December 31,
	2022		2021
Weighted average remaining lease term in years	—		0.2
Weighted average discount rate ⁽¹⁾	—	%	0.4	%

⁽¹⁾ The contracts are denominated in euros. The discount rate was determined on a currency-equivalent basis.

In December 2021 the Company extended the lease term of existing operating leases for the office and laboratory space in Vienna, Austria. The respective lease liabilities were remeasured and the amounts resulting from the remeasurement of the lease liability were recognized as an adjustment to the corresponding right of use asset. Also in December 2021, the Company reduced the lease term for existing operating and finance leases related to an agreement with a contract manufacturing organization for the production of clinical trial material and accounted for the proportionate decrease in the lease liability and the right of use asset with the difference recognized as a loss of $1.0 million on lease modification in operating research and development expenses on the income statement.

Until March 2021, the Company subleased certain of its leased real estate that it did not utilize to a third party. The sublease was qualified as an operating lease. The Company recognized sublease income in its consolidated statements of operations and comprehensive loss. The sublease had no influence on the Company’s accounting for the head lease.

Accrued expenses and other current liabilities

12 Months Ended

Dec. 31, 2022

Accrued expenses and other current liabilities

Accrued expenses and other current liabilities

8. Accrued expenses and other current liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):


	December 31,		December 31,
	2022		2021
Salaries and bonuses		4,481		4,754
Social security contributions		267		250
Unearned grant income (current)		300		693
Sublicense fees		1,220		304
Accrued external research and development expenses		3,458		2,165
Accrued external general and administration expenses		898		629
Accrued for property and equipment acquisitions		—		7
Finance lease liabilities		—		21
Income taxes		230		—
Other accruals and liabilities		324		57
	$	11,178	$	8,880

Loans payable

12 Months Ended

Dec. 31, 2022

Loans payable

Loans payable

9. Loans payable

As of December 31, 2022 and December 31, 2021, loans payable consisted of the following (in thousands):


	December 31,		December 31,
	2022		2021
Loans from FFG	$	2,855	$	6,074
Unamortized debt discount		(350)		(1,063)
Total loans payable, net	$	2,505	$	5,011

In connection with the funding agreements with the Austrian Research Promotion Agency, (Österreichische Forschungsförderungsgesellschaft, or “FFG”), the Company has received various loans (“FFG Loans”). The FFG Loans were made on a project-by-project basis. Amounts due under the FFG Loans bear interest at a rate of 0.75% per annum and mature at various dates between March 2023 and March 2024. Interest on amounts due under the loans is payable semi-annually in arrears, with all principal and remaining accrued interest due upon maturity.

The FFG Loans bear interest at rates that are below market rates of interest. The Company accounts for the imputed benefit arising from the difference between an estimated market rate of interest and the rate of interest charged by FFG as grant income from FFG. On the date that FFG loan proceeds are received, the Company recognizes the

portion of the loan proceeds allocated to grant funding as a discount to the carrying value of the loan and as unearned income, which is recognized as grant income over the term of the funding agreement.

The Company recognized grant income of $0.6 million, $0.8 million and $0.7 million during the years ended December 31, 2022, 2021 and 2020, respectively, related to the recognition of the unearned income recorded for the imputed benefit of FFG Loans at below-market interest rates. Unearned income (current) related to the imputed benefit of FFG Loans at below-market interest rates was $0.3 million and $0.7 million as of December 31, 2022 and 2021, respectively, and unearned income (non-current) presented under loans payable non-current related to such benefit was $0.1 million and $0.4 million as of December 31, 2022 and 2021, respectively.

In addition, the Company has recorded a discount to the carrying value of each FFG Loan for the portion of the loan proceeds allocated to grant funding, which is being amortized to interest expense over the term of the loan using the effective interest method. As of December 31, 2022 and 2021, the unamortized debt discount related to FFG Loans was $0.4 million and $1.1 million, respectively.

The Company recognized interest expense of $0.7 million, $0.9 million and $0.8 million during the years ended December 31, 2022, 2021 and 2020, respectively, related to the FFG Loans, which included interest expense related to the amortization of debt discount of $0.7 million, $0.8 million and $0.7 million during the years ended December 31, 2022, 2021 and 2020, respectively. A principal repayment of $2.8 million, and no principal repayment was made in the years ended December 31, 2022 and 2021, respectively.

The Company uses an estimated market rate of 20%, which was determined based on an average of the available interest rates on unsecured loans to comparable companies. A 10% increase or decrease in the estimated market rate of interest would have no material impact on grant income or liabilities.

In the event that the underlying program research results in a scientific or technical failure, the principal then outstanding under any loan may be forgiven by FFG on a project-by-project basis. The FFG Loans contain no financial covenants and are not secured by any of the Company's assets.

As of December 31, 2022, the aggregate minimum future principal payments due in connection with the FFG Loans are summarized as follows (in thousands):


Payments Due by Calendar Year	Amount
2023		1,721
2024		1,134
2025		—
2026		—
2027		—
Thereafter		—
Total	$	2,855

Common stock, Class A common stock and convertible preferred stock

12 Months Ended

Dec. 31, 2022

Common stock, Class A common stock and convertible preferred stock

Common stock, Class A common stock and convertible preferred stock

10. Common stock, Class A common stock and convertible preferred stock

The Company’s capital structure consists of common stock, Class A common stock and preferred stock. As of December 31, 2022, the Company was authorized to issue 200,000,000 shares of common stock, 3,900,000 shares of Class A common stock and 10,000,000 shares of preferred stock. The Company has designated 2,978 of the 10,000,000 authorized shares of preferred stock as non-voting Series A convertible preferred stock and 15,800 of the 10,000,000 authorized shares of preferred stock as non-voting Series A-1 convertible preferred stock. As of December 31, 2022, the Company had 52,317,138 shares of common stock, 2,399,517 shares of Class A common stock, 1,697 shares of Series A convertible preferred stock and 15,800 shares of Series A-1 convertible preferred stock outstanding and issued.

In July 2022 and August 2022 certain of the Company’s stockholders elected to convert an aggregate of 1,420,215 shares (769,734 and 650,481 shares, respectively) of Class A common stock owned by such holders into an aggregate of 1,420,215 shares of the Company’s common stock.

On February 15, 2022, the Company entered into a Stock Purchase Agreement (the “Stock Purchase Agreement”) with Gilead, that requires Gilead, at the Company’s option, to purchase up to $35.0 million of the Company’s common stock. On February 15, 2022, Gilead purchased an initial amount of 1,666,666 shares of the Company’s common stock in exchange for $5.0 million in cash at a purchase price per share equal to $3.00. Pursuant to the terms of the Stock Purchase Agreement, the Company may require Gilead to purchase the balance of the $30.0 million of common stock, at the discretion of the Company, in one or two subsequent purchases at a price equal to the volume weighted average purchase price preceding such purchase, as defined in the Stock Purchase Agreement, plus, for the first subsequent purchase, which can be up to the full $30.0 million balance, a premium of 30%. The Company’s right to sell shares of its common stock to Gilead is subject to specified limitations, including a limitation that prevents the Company from requesting purchases of shares of common stock by Gilead that would result in a beneficial ownership of more than 19.9% of the total number of outstanding shares of common stock by Gilead. At December 31, 2022, this limitation would have prevented the Company from requesting that Gilead purchase the full $30.0 million balance of the investment commitment. The Company agreed to file a registration statement on Form S-3 to register for resale any additional shares of common stock issued to Gilead within four months from issuance.

On March 4, 2022, the Company closed a public offering of 21,700,000 shares of its common stock and of 15,800 shares of Series A-1 convertible preferred stock at a public offering price of $2.00 and $2,000.00 per share, respectively, for net proceeds of $70.2 million after deducting underwriting discounts and commissions and offering expenses including pro-rata ATM expenses.

The Company has two series of preferred stock authorized, issued and outstanding as of December 31, 2022: Series A convertible preferred stock and Series A-1 convertible preferred stock. Shares of Series A and Series A-1 convertible preferred stock may be independently converted into common stock. Holders of Series A and Series A-1 convertible preferred stock have equal rights, powers and privileges.

Holders of common stock are entitled to one vote for each share held on all matters submitted to a vote of the stockholders. The holders of Class A common stock and Series A and Series A-1 convertible preferred stock are not entitled to vote, except as required by law. The holders of common stock and Class A common stock do not have any cumulative voting rights.

Each holder of Class A common stock has the right to convert each share of Class A common stock into one share of common stock at such holder's election. Each holder of Series A and Series A-1 convertible preferred stock has the right to convert each share of Series A and Series A-1 convertible preferred stock into 1,000 shares of common stock at any time at the holder’s option, provided that the holder will be prohibited, subject to certain exceptions, from converting Series A and Series A-1 preferred stock into shares of our common stock if, as a result of such conversion, the holder, together with its affiliates, would own more than 9.99% of the total number of shares of the Company’s common stock then issued and outstanding

Holders of common stock and Class A common stock are entitled to receive ratably any dividends declared by the board of directors out of funds legally available for that purpose, subject to any preferential dividend rights of any outstanding preferred stock. Holders of Series A and Series A-1 preferred stock will be entitled to receive dividends at a rate equal to (on an as-if-converted-to-common stock basis), and in the same form and manner as, dividends actually paid on shares of the Company’s common stock. Holders of common stock and Class A common stock have no preemptive rights, conversion rights, or other subscription rights or redemption or sinking fund provisions.

In the event of a liquidation, dissolution, or winding up of the Company, holders of our Series A and Series A-1 preferred stock will receive a payment equal to $0.001 per share of Series A and Series A-1 preferred stock before any proceeds are distributed to the holders of common stock. Then, holders of common stock and Class A common stock will be entitled to share ratably in all assets remaining after payment of all debts and other liabilities.

There were 1,697 shares of Series A convertible preferred stock outstanding as of December 31, 2022 and December 31, 2021, respectively. In October 2021 and December 2021 certain of the Company’s stockholders elected to convert an aggregate of 1,281 shares (55 and 1,226 shares, respectively) of Series A convertible preferred stock owned by such holders into an aggregate of 1,281,000 shares of the Company’s common stock.

- Definition

The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-URI https://asc.fasb.org/topic&trid=2208762

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496158-112644

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496158-112644

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 14
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496171-112644

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 14
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496171-112644

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI https://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 18
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496189-112644

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (g)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496158-112644

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 18
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496189-112644

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (h)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496158-112644

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 14
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496171-112644

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 18
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496189-112644

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 16
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496180-112644

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (i)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496158-112644

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-Paragraph 1
-Subparagraph (SX 210.4-08(e)(1))
-URI https://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126731327&loc=SL126733271-114008

+ Details

Stock-based compensation

12 Months Ended

Dec. 31, 2022

Stock-based compensation

Stock-based compensation

11. Stock-based compensation

2018 Stock Option and Grant Plan

In June 2018, the Board of Directors approved the 2018 Stock Option and Grant Plan. Options granted under the 2018 Stock Option and Grant Plan generally vest over four years, with 25% of the options vesting upon the first anniversary of the grant date and the remaining 75% of the options vesting in 12 equal quarterly installments following the first anniversary of the grant date, provided the option holder continues to have an employment or service relationship with the Company on each vesting date. The options expire on the 10^th anniversary of the grant date. As of December 31, 2022, 900,796 options granted under the 2018 Stock Option and Grant Plan remained outstanding. Any authorization to issue new options under the 2018 Stock Option and Grant Plan was cancelled upon the effectiveness of the 2019 Stock Option and Incentive Plan and no further awards will be granted under the 2018 Plan.

2019 Stock Option and Incentive Plan

On April 1, 2019, the Company’s stockholders approved the 2019 Stock Option and Incentive Plan, which became effective as of the effective date of the registration statement in connection with the Company’s IPO. The plan provides for the grant of shares of restricted stock, long term incentive awards, stock options or other equity-based awards. As of December 31, 2022, the maximum number of shares of the Company’s common stock that may be issued under the Company’s 2019 Stock Option and Incentive Plan was 5,878,814 shares which shall be cumulatively increased each year by up to 4.0% of the then outstanding number of shares of common stock and Class A common stock. Options granted under the 2019 Stock Option and Incentive Plan generally vest over four years, with 25% of the options vesting upon the first anniversary of the grant date and the remaining 75% of the options vesting in 12 equal quarterly installments following the first anniversary of the grant date, provided the option holder continues to have an employment or service relationship with the Company on each vesting date. Initial options granted to non-executive directors upon their election generally vest over a three-year term with 33% of the options vesting upon the first anniversary of the grant date and the remaining 67% of the options vesting in eight equal quarterly installments following the first anniversary of the grant date. Option re-grants to non-executive directors generally vest on the first anniversary of the grant date. The options expire on the 10^th anniversary of the grant date. For each option the beneficiary is entitled to receive one share of common stock upon the exercise of the option.

Stock option valuation

The Company estimates the option’s fair value on the date of grant using the Black-Scholes option-pricing model. Black-Scholes utilizes assumptions related to expected term, volatility, the risk-free interest rate, the dividend and employee exercise behavior. Forfeitures are accounted for when they occur. Expected volatilities utilized in the Black-Scholes model are based on historical volatilities of a group of comparable companies. The group of representative companies have characteristics similar to the Company, including the stage of product development and focus on the life science industry. Management believes that this represents the most accurate basis for estimating expected future volatilities under the current conditions. The risk-free interest rate is derived from the yields for

U.S. Treasuries with a remaining term approximating the expected life of the options. The expected term represents the period of time that the options granted are expected to be outstanding.

The following table summarizes, on a weighted average basis, the assumptions used in the Black-Scholes option-pricing model for estimating the fair value of stock options granted during:


	Year ended December 31,
	2022		2021		2020

Risk-free interest rate	3.09	%	1.07	%	0.44	%
Expected term (in years)	6.0		6.1		6.1
Expected volatility	85.4	%	85.5	%	80.2	%
Expected dividends	—	%	—	%	—	%

For the 2020, 2021 and 2022 grants, the Company used the simplified method in developing an estimate of the expected term due to a lack of historical exercise data.

Stock option activity

The following table summarizes the Company’s stock option activity since January 1, 2022 (in thousands, except share and per share amounts):


				Weighted
		Weighted		Average
		Average		Remaining	Aggregate
	Number of	Exercise		Contractual	Intrinsic
	Shares	Price		Term	Value
				(in years)
Outstanding as of December 31, 2021	4,231,178	$	9.21	7.5	$	1,640
Granted	2,709,523		1.55
Exercised	(34,223)		0.10
Forfeited	(373,955)		7.31
Outstanding as of December 31, 2022	6,532,523	$	6.19	7.7	$	490

Options exercisable as of December 31, 2022	3,182,724	$	8.47	6.3	$	489
Options unvested as of December 31, 2022	3,349,799	$	4.01	9.0	$	1

The aggregate intrinsic value of stock options was calculated as the difference between the exercise price of the stock options and the fair value of the Company’s common stock for those stock options that had exercise prices lower than the fair value of the Company’s common stock. The fair value per common stock used for calculating the intrinsic values as of December 31, 2022, December 31, 2021 and December 31, 2020, was $0.81, $2.33 and $11.09, respectively.

The aggregate intrinsic value of options exercised during the years ended December 31, 2022, 2021 and 2020 was $0.1 million, $1.0 million and $2.9 million, respectively.

The weighted average grant-date fair value per share of stock options granted during the years ended December 31, 2022, 2021 and 2020 was $1.55, $11.46 and $8.95, respectively.

The total fair value of stock options vested during the years ended December 31, 2022 and 2021 was $7.9 million and $6.0 million, respectively.

Cash received from stock option exercise under share-based payment arrangements for the years ended December 31, 2022, 2021 and 2020 was $3 thousand, $203 thousand and $63 thousand, respectively.

Restricted Stock Units

In the year ended December 31, 2020, the Company granted 43,700 restricted stock units to officers, employees and a consultant to compensate them for a temporary salary or fee reduction in response to the coronavirus pandemic. The restricted stock units were subject to time-based vesting conditions and generally vested between March 2021 and November 2021. Expenses were recorded using the graded-vesting method. In the years ended December 31, 2022 and 2021, the Company has not issued restricted stock units.

Common Stock Awards

In the year ended December 31, 2022 the Company issued unrestricted shares of common stock to members of its executive team who agreed to convert a portion of their base salaries, for the six months ended June 30, 2022, for shares of the Company’s fully vested common stock having a value equal to their foregone salary. The number of shares of fully vested common stock was determined based on a value of $3.00 per share, resulting in the issuance of 112,551 shares of common stock. The total fair value of common stock awards issued during the three months ended March 31, 2022 was $0.2 million. The grant date fair value per share of common stock was $1.50 and was measured at the closing price of the common stock on the date of grant. Expenses were recorded immediately and were included in stock based compensation in the three months ended March 31, 2022. No unrestricted shares of common stock were issued in the year ended December 31, 2021. In the year ended December 31, 2020, the Company issued 36,249 unrestricted shares of common stock to the non-executive members of its Board of Directors.

Stock-based compensation

Stock-based compensation expense was classified in the consolidated statements of operations and comprehensive loss as follows (in thousands):


	Year ended December 31,
	2022		2021		2020
Research and development expenses	$	2,074	$	3,200	$	3,084
General and administrative expenses		2,969		4,444		5,573
	$	5,043	$	7,644	$	8,657

As of December 31, 2022 total unrecognized compensation cost related to the unvested stock-based awards was $4.7 million, which is expected to be recognized over a weighted average period of 1.5 years.

Income taxes

12 Months Ended

Dec. 31, 2022

Income taxes

Income taxes

12. Income taxes

Income tax expense during the years ended December 31, 2022 resulted from US federal and state income tax as well as minimum tax obligations in Austria. From inception through December 31, 2021, we have not been required to pay U.S. federal and state income taxes because of current and accumulated net operating losses. Income tax expense during the years ended December 31, 2021 and 2020 resulted from minimum tax obligations. During the years ended December 31, 2022, 2021 and 2020, the Company recorded no income tax benefits for the net operating losses incurred

in each year, due to its uncertainty of realizing a benefit from those items. The Company's losses before income taxes were generated in the United States and Austria.

For financial reporting purposes, losses before income taxes for the years ended December 31, 2022, 2021 and 2020 consisted of the following (in thousands):


	Year ended December 31,
	2022		2021		2020
United States	$	(7,222)	$	(11,403)	$	(11,603)
Foreign (Austria)		(57,463)		(64,261)		(32,479)
Net loss before tax	$	(64,685)	$	(75,664)	$	(44,082)

The components of the consolidated income tax provision for the years ended December 31, 2022, 2021 and 2020 were as follows (in thousands):


	Year ended December 31,
	2022		2021		2020
Current
Federal	$	217	$	—	$	—
State		12		—		—
Foreign (Austria)		1		1		0
Total current tax expense		230		1		0
Deferred
Federal		—		—		—
State		—		—		—
Foreign (Austria)		—		—		—
Total deferred tax expense		—		—		—

Total income tax expense	$	230	$	1	$	0

The Company's worldwide effective tax rate for the years ended December 31, 2022, 2021 and 2020 was 0.3%, 0.0% and 0.0%, respectively. The tax rate is affected by recurring items, such as tax rates in foreign jurisdictions and the relative amounts of income earned in those jurisdictions, which is expected to be fairly consistent in the near term. It is also affected by discrete items that may occur in any given year, but are not consistent from year to year. The following

items had the most significant impact on the difference between the statutory U.S. federal income tax rate of 21% for the years ended December 31, 2022, 2021 and 2020 and the effective tax rate:


	Year ended December 31,
	2022			2021			2020
U.S. federal statutory income tax rate		(21.0)	%		(21.0)	%		(21.0)	%
State income taxes, net of federal benefit		—			—			—
Foreign tax rate differential⁽¹⁾		(4.0)			(4.0)			(4.0)
Not taxable government grants⁽²⁾		(3.8)			(3.8)			(4.7)
Stock-based compensation⁽³⁾		0.5			(1.5)			(1.0)
Global intangible low-taxed income⁽⁴⁾		1.4			—			—
Other		0.1			0.1			0.5
Change in deferred tax asset valuation allowance⁽⁵⁾		27.1			30.2			30.2
Effective income tax rate		0.3	%		—	%		—	%

⁽¹⁾ The 4% increase for the years ended December 31, 2022, 2021 and 2020, respectively, resulted from tax rate differences between U.S. and non-U.S. jurisdictions. Net loss before tax was principally generated in Austria, where the statutory tax rate is 25%.

⁽²⁾For the years ended December 31, 2022, 2021 and 2020, 3.8%, 3.8% and 4.7% increase, respectively, resulted from non-taxable research subsidies received from Austrian government agencies.

⁽³⁾For the years ended December 31, 2022, 2021 and 2020, 0.5% decrease, 1.5% and 1.0% increase, respectively, resulted from non-taxable Stock-based compensation expense.

⁽⁴⁾For the years ended December 31, 2022, 2021 and 2020, 1.4% decrease, and no change, respectively, resulted from global intangible low-taxed income taxes.

⁽⁵⁾For the years ended December 31, 2022, 2021 and 2020, 27.1% reduction, 30.2% reduction and 30.2% reduction, respectively, resulted from changes in valuation allowance on deferred tax assets. Deferred tax assets will only be recovered when the generation of future taxable income is more likely than not. Due to the nature of the Company's research activities and the inherent uncertainties the deferred tax assets are fully offset by a valuation allowance.

Components of the net deferred tax assets or liabilities as of the years ended December 31, 2022 and 2021 consisted of the following (in thousands):


	Year ended December 31,
	2022		2021
Deferred tax assets:
Net operating loss carryforwards	$	66,201	$	55,752
Capitalized R&D expenses		1,354		—
Credit carryforwards		64		64
Accrued expenses and other		366		357
Stock-based compensation		1,251		1,209
Operating lease liabilities		918		1,378
Finance lease liabilities		—		5
Total deferred tax assets		70,154		58,765
Valuation allowance		(65,774)		(53,728)
Total deferred tax assets		4,380		5,037

Deferred tax liabilities:
Accrued expenses and other		(3,450)		(3,604)
Fixed assets		(10)		(11)
Operating lease right of use asset		(920)		(1,400)
Finance lease right of use asset		—		(22)
Total deferred tax liabilities		(4,380)		(5,037)

Net deferred tax assets	$	—	$	—

As of December 31, 2022, 2021 and 2020, the Company had Austrian net operating loss carryforwards of $275.3 million, $219.7 million and $163.2 million, respectively. The Company had federal net operating loss carryforwards as of December 31, 2021 that were generated after December 31, 2017 of $17.9 million that do not expire, however these carryforwards are limited to 80% of the taxable income in any one tax period. The Company generated US taxable income in the current year and was able to offset 80% the taxable income utilizing net operating loss carryforwards which gave rise to current taxes during 2022. The federal net operating loss carryforward as of December 31, 2022 were $13.8 million, and US Federal net operating loss carryforwards as of December 31, 2020 were $8.3 million. The Company has evaluated the positive and negative evidence bearing upon its ability to realize the deferred tax assets resulting from its net operating loss carryforwards. Management has considered the Company's history of cumulative net losses incurred since inception and the uncertainties related to the long period necessary to achieve profits from commercialization of any products and has concluded that it is more likely than not that the Company will not realize the benefits of its deferred tax assets. Accordingly, a full valuation allowance has been established against the deferred tax assets as of December 31, 2022, 2021 and 2020. According to a tax reform in Austria in 2022, the corporate income tax rate will be reduced from 25.0% to 24.0% in 2023 and to 23.0% in 2024. The future tax rate of 23.0% was used to determine deferred taxes and the valuation allowance for the Austrian business. Management reevaluates the positive and negative evidence at each reporting period.

The amount of the deferred tax asset considered realizable, however, could be adjusted if estimates of future taxable income during the carryforward period are reduced or increased or if objective negative evidence in the form of

losses is no longer present and additional weight may be given to subjective evidence. The tax years in which the tax carryforwards were generated may still be adjusted upon examination by the tax authorities.

Changes in the valuation allowance for deferred tax assets during the years ended December 31, 2022, 2021 and 2020 related primarily to the increases in net operating loss carryforwards as follows (in thousands):


	Year ended December 31,
	2022		2021		2020
Valuation allowance at beginning of period	$	(53,728)	$	(46,064)	$	(32,583)
Increases		(12,046)		(7,664)		(13,481)
Valuation allowance at end of period	$	(65,774)	$	(53,728)	$	(46,064)

On December 22, 2017, the United States enacted the Tax Cuts and Jobs Act (“Tax Reform Legislation” or “TCJA”). The Tax Reform Legislation introduced section 951A, a new tax on so-called “global intangible low-taxed income”. GILTI applies to income of a controlled foreign corporation (“CFC”) that is not otherwise subpart F income, and consists of the excess "tested income" over a 10% return on the CFC's “qualified business asset investment,” or “QBAI”. QBAI is the total tax basis of the CFC's depreciable, tangible property used in the production of tested income. The full amount of GILTI is included in taxable income. The GILTI inclusion is then reduced by 50% (reduced to 37.5% after 2025). However, that reduction in GILTI may be limited based on the level of U.S. taxable income. A limited allowance for foreign tax credits is allowed that would reduce the U.S. tax cost. GILTI foreign tax credits can only reduce U.S. taxes owed on GILTI and are not eligible for carryforward. The Company's Austrian subsidiary falls under the category of a CFC and due to the nature of its business model as a technology company, there may not be a material amount of tangible assets if this subsidiary starts to generate profits. GILTI taxation therefore may be applicable. The Company recognized $3.6 million of GILTI for the year ended December 31, 2022 and no GILTI for the year ended December 31, 2021, respectively.

The Company files income tax returns in the U.S. federal jurisdiction as well as in New York. The tax years from 2018 to present remain open to examination by the jurisdictions in which the Company is subject to tax. There are currently no pending income tax examinations in the U.S. Furthermore, the Company files income tax returns in Austria. The tax years 2018 to present remain open to examination by the jurisdiction. There are currently no pending income tax examinations in Austria.

The Company evaluates tax positions for recognition using a more likely than not recognition threshold, and those tax positions eligible for recognition are measured as the largest amount of tax benefit that is greater than 50% likely of being realized upon the effective settlement with a taxing authority that has full knowledge of all relevant information. As of December 31, 2022 and 2021, the Company had no unrecognized income tax benefits that would affect the Company’s effective tax rate if recognized.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Commitments and contingencies

12 Months Ended

Dec. 31, 2022

Commitments and contingencies

Commitments and contingencies

13. Commitments and contingencies

Contract manufacturing arrangements

The Company has entered into arrangements with contract manufacturing organizations (“CMOs”) for manufacturing of materials for research and development purposes, including manufacturing of clinical trial materials. These contracts generally provide for non-cancellable obligations or cancellation penalties depending on the time of cancellation. As of December 31, 2022, the Company’s total non-cancellable obligations under contracts with CMOs were $9.3 million, of which $9.2 million relate to 2023 deliverables and $0.1 million relate to 2024 deliverables.

Intellectual property licenses

The Company has entered into certain license agreements under which it is obligated to make milestone payments upon the achievement of certain development and regulatory milestones, to pay royalties on net sales of licensed products, and to pay a percentage of the sublicense fees which the Company receives from its sublicensees.

In the years ended December 31, 2022, 2021 and 2020, the Company recorded $1.0 million, $1.3 million and $1.2 million, respectively, in licensing fees related to intellectual property licenses as research and development expenses. The amounts for the years ended December 31, 2021 and 2020 mainly related to the upfront payment and milestone payments received by the Company under the Gilead Collaboration Agreement. The amount for the year ended December 31, 2022 mainly related to the upfront payment and milestone payments received by the Company under the Gilead Collaboration Agreement and the Roche Collaboration Agreement. The amounts recognized as expenses have been agreed to by the licensors but calculation of sublicensing fees on future payments may be subject to interpretation and may change until agreed to by the receiving party.

Indemnification agreements

In the ordinary course of business, the Company may provide indemnification of varying scope and terms to vendors, lessors, business partners and other parties with respect to certain matters including, but not limited to, losses arising out of breach of such agreements or from intellectual property infringement claims made by third parties. In addition, the Company has entered into indemnification agreements with members of its Board of Directors and senior management that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is, in many cases, unlimited. To date, the Company has not incurred any material costs as a result of such indemnifications. The Company is not aware of any claims under indemnification arrangements, and it has not accrued any liabilities related to such obligations in its consolidated financial statements as of December 31, 2022 or December 31, 2021.

Legal proceedings

At each reporting date, the Company evaluates whether or not a potential loss amount or a potential range of loss is probable and reasonably estimable under the provisions of the authoritative guidance that addresses accounting for contingencies. The Company is currently a party to a patent proceeding opposing European Patent No. 3218504, which was granted to the University of Geneva in July 2020 and is exclusively licensed to the Company. While it is not feasible to predict the outcome of these matters with certainty, and some lawsuits, claims or proceedings may be disposed or decided unfavorably, the Company does not expect that the pending patent opposition, and any asserted or unasserted legal claims or proceedings, individually or in the aggregate, will have a material adverse effect on the Company. However, if, as a result of the current patent proceeding, the Company would lose all, or at least part, of the protection under the opposed patent, such loss could erode the Company’s competitive position and harm its business and ability to achieve profitability. The Company expenses the costs related to the pending and other such legal proceedings as incurred.

401(k) Savings Plan

12 Months Ended

Dec. 31, 2022

401(k) Savings Plan

401(k) Savings Plan

14. 401(k) Savings Plan

The Company established a defined contribution savings plan under Section 401(k) of the Internal Revenue Code. This plan provides that eligible employees can elect to contribute to the 401(k) Plan, subject to certain limitations, on a pretax basis. The Company matches up to 100% of the first 4% of each employee’s contribution. During the years ended December 31, 2022, December 31, 2021 and December 31, 2020 expenses recognized for the 401(k) Plan were $0.6 million, $0.4 million and $0.2 million, respectively.

- Definition

The entire disclosure for retirement benefits.

+ References

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+ Details

Net loss per share

12 Months Ended

Dec. 31, 2022

Net loss per share

Net loss per share

15. Net loss per share

The following table sets forth the computation of the basic and diluted net loss per share attributable to common stockholders (in thousands, except for per share amounts):


	Year ended December 31,
	2022		2021		2020
Numerator:
Net loss	$	(64,915)	$	(75,665)	$	(44,082)

Denominator:
Weighted-average common shares outstanding, basic and diluted		50,743,080		29,945,954		25,876,376
Weighted-average Series A convertible preferred shares outstanding, basic and diluted, presented as if converted into common stock⁽¹⁾		1,697,000		2,887,636		162,732
Weighted-average Series A-1 convertible preferred shares outstanding, basic and diluted, presented as if converted into common stock⁽¹⁾		13,072,877		—		—
Total number of shares used to calculate net loss per share, basic and diluted		65,512,957		32,833,590		26,039,108

Net loss per share, basic and diluted	$	(0.99)	$	(2.30)	$	(1.69)

⁽¹⁾ Class A common stock, Series A and Series A-1 convertible preferred stock are participating securities that have substantially the same terms and features as the Company’s common stock. The Class A common stock, Series A and Series A-1 convertible preferred stock is therefore included in the weighted-average number of shares outstanding to calculate net loss per share, basic and diluted as if converted in common stock. Each share of Class A common stock, Series A and Series A-1 convertible preferred stock is independently convertible into one and 1,000 shares of common stock, respectively. 2,399,517 shares of the Company’s common stock are issuable upon conversion of the Class A common stock, 1,697,000 shares of the Company’s common stock are issuable upon conversion of Series A convertible preferred stock and 15,800,000 shares of the Company’s common stock are issuable upon conversion of Series A-1 convertible preferred stock (see Note 10).

Since the Company was in a loss position for all periods presented, basic net loss per share is the same as diluted net loss per share for all periods as the inclusion of all potential common shares (common stock and Class A common stock) outstanding would have been anti-dilutive. Potentially dilutive securities that were not included in the diluted per share calculations because they would be anti-dilutive were as follows:


	Year ended December 31,
	2022	2021	2020
Options issued and outstanding	6,532,523	4,231,178	3,555,945
Unvested restricted stock units	—	—	43,700
Total	6,532,523	4,231,178	3,599,645

Related parties

12 Months Ended

Dec. 31, 2022

Related parties

Related parties

16. Related parties

Following the expiry of the consultancy agreement between the Company and its Chief Scientific Officer, Daniel Pinschewer, on March 19, 2020 the Company entered into a new consultancy agreement with Daniel Pinschewer on March 20, 2020, pursuant to which he serves as Scientific Advisor to the Chief Executive Officer.

The Company is party to research and service arrangements with the University of Basel. Daniel Pinschewer, formerly Chief Scientific Officer, and his spouse are employees of the University of Basel and both involved in providing the services under these arrangements. Payments to the University of Basel during Daniel Pinschewer’s term as Chief Scientific Officer were reported as related party transactions but payments following the expiry of that role in March 2020 were no longer considered related party transactions.

In the years ended December 31, 2022 and December 31, 2021, the Company did not record any related party transactions. In the year ended December 31, 2020 the Company recorded $0.3 million in research and development expenses for service fees paid to the University of Basel, which represented related party transactions.

The University of Basel is also entitled to receive de minimis royalties on the net sales of any product that is based on a patent created by the Company’s Scientific Advisor to the Chief Executive Officer in the course of his consulting services to the Company. In the years ended December 31, 2022, 2021 and 2020, no royalties were paid pursuant to the terms of this arrangement.

Summary of significant accounting policies (Policies)

12 Months Ended

Dec. 31, 2022

Summary of significant accounting policies

Basis of presentation

Going concern

Use of estimates

Foreign currency and currency translation

The functional currency for the Company is the United States dollar and the functional currency for the Company's wholly owned foreign subsidiary, Hookipa Biotech GmbH, is the euro.

Concentrations of credit risk and of significant suppliers

Cash equivalents

Deferred offering costs

Fair value measurements

levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable:

●

Level 1 - Quoted prices in active markets for identical assets or liabilities.

●

The Company’s cash equivalents are carried at fair value, determined according to the fair value hierarchy described above (see Note 4).

Property and equipment


		Estimated useful life
Leasehold improvements		shorter of useful life or term of lease
Laboratory equipment		2 - 10 years
Furniture and fixtures		2 - 10 years
Computer equipment and software		2 - 4 years

Leases

Capitalized Software Development Cost

Impairment of long-lived assets

Segment information

the consolidated operating results to make decisions about the allocation of the Company's resources. The majority of the Company's tangible assets are held in Austria.

Revenue recognition from contracts with customers

The Company recognized revenue from collaboration and license agreements with Gilead and Roche.

Upfront payment and program initiation fee

Reimbursement for services

Research and development milestones

Sales-based milestones and royalty payments

Cost to fulfill contracts

Research and development costs

Research and manufacturing contract costs and accruals

Government grant agreements and research incentives

grant funding or proceeds from research and development incentives is recorded in the consolidated balance sheets as prepaid expenses and other current assets.

Stock-based compensation

Comprehensive loss

Net loss per share

The Company reported a net loss attributable to common stockholders for the years ended December 31, 2022, 2021 and 2020.

Income taxes

Recent accounting pronouncements

Adopted as of current period

Recently Issued Accounting Pronouncements

Summary of significant accounting policies (Tables)

12 Months Ended

Dec. 31, 2022

Summary of significant accounting policies

Schedule of estimated useful life of each asset


		Estimated useful life
Leasehold improvements		shorter of useful life or term of lease
Laboratory equipment		2 - 10 years
Furniture and fixtures		2 - 10 years
Computer equipment and software		2 - 4 years

Fair Value of Financial Assets (Tables)

12 Months Ended

Dec. 31, 2022

Fair Value of Financial Assets

Schedule of financial assets measured at fair value on a recurring basis


	Fair Value Measurement at December 31, 2022 Using
	Level 1		Level 2		Level 3		Total
Cash equivalents:
Money market funds	$	85,491	$	—	$	—	$	85,491
Total	$	85,491	$	—	$	—	$	85,491


	Fair Value Measurement at December 31, 2021 Using
	Level 1		Level 2		Level 3		Total
Cash equivalents:
Money market funds	$	35,403	$	—	$	—	$	35,403
Total	$	35,403	$	—	$	—	$	35,403

Property, plant and equipment, net (Tables)

12 Months Ended

Dec. 31, 2022

Property, plant and equipment, net.

Schedule of property, plant and equipment, net

Property, plant and equipment, net consisted of the following (in thousands):


	December 31,		December 31,
	2022		2021

Land	$	1,959	$	2,072
Leasehold improvements		3,164		3,348
Construction in progress		10,567		7,746
Laboratory equipment		7,403		7,025
Furniture and fixtures		622		651
Computer equipment and software		2,034		1,876
Property and equipment, gross		25,749		22,718
Less: Accumulated depreciation		(7,779)		(6,366)
Property and equipment, net	$	17,970	$	16,352

Leases (Tables)

12 Months Ended

Dec. 31, 2022

Leases

Schedule of operating and finance leases presentation in the consolidated balance sheets


		December 31,		December 31,
	Balance sheet location	2022		2021
Assets
Operating lease assets, net	Operating lease right of use assets	$	4,006	$	5,673
Finance lease assets, net	Finance lease right of use assets		—		90
Total lease assets			4,006		5,763
Liabilities
Current operating lease liability	Operating lease liabilities, current		1,688		1,682
Current finance lease liability	Accrued expenses and other current liabilities		—		21
Total current lease liabilities			1,688		1,703
Non-current operating lease liability	Operating lease liabilities, non-current		2,310		3,911
Non-current finance lease liability	Other non-current liabilities		—		—
Total non-current lease liabilities			2,310		3,911
Total lease liabilities		$	3,998	$	5,614

Summary of the effect of lease costs

The following table summarizes the effect of lease costs in the Company’s consolidated statements of operations and comprehensive loss (in thousands):


		Year ended		Year ended		Year ended
	Income statement location	December 31, 2022		December 31, 2021		December 31, 2020
Operating lease expenses	Research and development expenses	$	1,430	$	1,910		1,654
	General and administrative expenses		219		203		376
Finance lease amortization expenses	Research and development expenses		89		425		395
	General and administrative expenses		—		7		21
Interest on finance lease liabilities	Interest expenses		0		5		8
Sublease income	Other income (expense)		—		(40)		(155)
Net lease expense		$	1,738	$	2,510		2,299

Summary of maturities of operating lease liabilities

The minimum lease payments for the next five years and thereafter are expected to be as follows (in thousands):


	December 31, 2022
	Operating lease
2023		1,570
2024		1,316
2025		1,174
2026		—
2027		—
Thereafter		—
Total lease payments		4,060
Less: interest		62
Present value of lease liabilities	$	3,998

Schedule of weighted average remaining lease term and weighted average discount rate of operating leases

The weighted average remaining lease term and weighted average discount rate of operating leases are as follows:


	December 31,		December 31,
	2022		2021
Weighted average remaining lease term in years	2.8		3.7
Weighted average discount rate ⁽¹⁾	1.3	%	1.3	%

⁽¹⁾ The majority of the contracts are denominated in euros. The discount rate was determined on a currency-equivalent basis.

Schedule of weighted average remaining lease term and weighted average discount rate of finance leases

The weighted average remaining lease term and weighted average discount rate of finance leases are as follows:


	December 31,		December 31,
	2022		2021
Weighted average remaining lease term in years	—		0.2
Weighted average discount rate ⁽¹⁾	—	%	0.4	%

⁽¹⁾ The contracts are denominated in euros. The discount rate was determined on a currency-equivalent basis.

Accrued expenses and other current liabilities (Tables)

12 Months Ended

Dec. 31, 2022

Accrued expenses and other current liabilities

Schedule of accrued expenses and other current liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):


	December 31,		December 31,
	2022		2021
Salaries and bonuses		4,481		4,754
Social security contributions		267		250
Unearned grant income (current)		300		693
Sublicense fees		1,220		304
Accrued external research and development expenses		3,458		2,165
Accrued external general and administration expenses		898		629
Accrued for property and equipment acquisitions		—		7
Finance lease liabilities		—		21
Income taxes		230		—
Other accruals and liabilities		324		57
	$	11,178	$	8,880

Loans payable (Tables)

12 Months Ended

Dec. 31, 2022

Loans payable

Schedule of loans payable

As of December 31, 2022 and December 31, 2021, loans payable consisted of the following (in thousands):


	December 31,		December 31,
	2022		2021
Loans from FFG	$	2,855	$	6,074
Unamortized debt discount		(350)		(1,063)
Total loans payable, net	$	2,505	$	5,011

Schedule of aggregate minimum future principal payments due in connection with the FFG Loans

As of December 31, 2022, the aggregate minimum future principal payments due in connection with the FFG Loans are summarized as follows (in thousands):


Payments Due by Calendar Year	Amount
2023		1,721
2024		1,134
2025		—
2026		—
2027		—
Thereafter		—
Total	$	2,855

Stock-based compensation (Tables)

12 Months Ended

Dec. 31, 2022

Stock-based compensation

Schedule of assumptions used in the Black-Scholes option-pricing model for estimating the fair value of stock options


	Year ended December 31,
	2022		2021		2020

Risk-free interest rate	3.09	%	1.07	%	0.44	%
Expected term (in years)	6.0		6.1		6.1
Expected volatility	85.4	%	85.5	%	80.2	%
Expected dividends	—	%	—	%	—	%

Schedule of summary of stock option activity

The following table summarizes the Company’s stock option activity since January 1, 2022 (in thousands, except share and per share amounts):


				Weighted
		Weighted		Average
		Average		Remaining	Aggregate
	Number of	Exercise		Contractual	Intrinsic
	Shares	Price		Term	Value
				(in years)
Outstanding as of December 31, 2021	4,231,178	$	9.21	7.5	$	1,640
Granted	2,709,523		1.55
Exercised	(34,223)		0.10
Forfeited	(373,955)		7.31
Outstanding as of December 31, 2022	6,532,523	$	6.19	7.7	$	490

Options exercisable as of December 31, 2022	3,182,724	$	8.47	6.3	$	489
Options unvested as of December 31, 2022	3,349,799	$	4.01	9.0	$	1

Schedule of stock-based compensation expense

Stock-based compensation expense was classified in the consolidated statements of operations and comprehensive loss as follows (in thousands):


	Year ended December 31,
	2022		2021		2020
Research and development expenses	$	2,074	$	3,200	$	3,084
General and administrative expenses		2,969		4,444		5,573
	$	5,043	$	7,644	$	8,657

Income taxes (Tables)

12 Months Ended

Dec. 31, 2022

Income taxes

Schedule of losses before income taxes

For financial reporting purposes, losses before income taxes for the years ended December 31, 2022, 2021 and 2020 consisted of the following (in thousands):


	Year ended December 31,
	2022		2021		2020
United States	$	(7,222)	$	(11,403)	$	(11,603)
Foreign (Austria)		(57,463)		(64,261)		(32,479)
Net loss before tax	$	(64,685)	$	(75,664)	$	(44,082)

Schedule of components of the consolidated income tax provision

The components of the consolidated income tax provision for the years ended December 31, 2022, 2021 and 2020 were as follows (in thousands):


	Year ended December 31,
	2022		2021		2020
Current
Federal	$	217	$	—	$	—
State		12		—		—
Foreign (Austria)		1		1		0
Total current tax expense		230		1		0
Deferred
Federal		—		—		—
State		—		—		—
Foreign (Austria)		—		—		—
Total deferred tax expense		—		—		—

Total income tax expense	$	230	$	1	$	0

Schedule of effective income tax rate reconciliation


	Year ended December 31,
	2022			2021			2020
U.S. federal statutory income tax rate		(21.0)	%		(21.0)	%		(21.0)	%
State income taxes, net of federal benefit		—			—			—
Foreign tax rate differential⁽¹⁾		(4.0)			(4.0)			(4.0)
Not taxable government grants⁽²⁾		(3.8)			(3.8)			(4.7)
Stock-based compensation⁽³⁾		0.5			(1.5)			(1.0)
Global intangible low-taxed income⁽⁴⁾		1.4			—			—
Other		0.1			0.1			0.5
Change in deferred tax asset valuation allowance⁽⁵⁾		27.1			30.2			30.2
Effective income tax rate		0.3	%		—	%		—	%

⁽²⁾For the years ended December 31, 2022, 2021 and 2020, 3.8%, 3.8% and 4.7% increase, respectively, resulted from non-taxable research subsidies received from Austrian government agencies.

⁽³⁾For the years ended December 31, 2022, 2021 and 2020, 0.5% decrease, 1.5% and 1.0% increase, respectively, resulted from non-taxable Stock-based compensation expense.

⁽⁴⁾For the years ended December 31, 2022, 2021 and 2020, 1.4% decrease, and no change, respectively, resulted from global intangible low-taxed income taxes.

Schedule of components of the net deferred tax assets or liabilities

Components of the net deferred tax assets or liabilities as of the years ended December 31, 2022 and 2021 consisted of the following (in thousands):


	Year ended December 31,
	2022		2021
Deferred tax assets:
Net operating loss carryforwards	$	66,201	$	55,752
Capitalized R&D expenses		1,354		—
Credit carryforwards		64		64
Accrued expenses and other		366		357
Stock-based compensation		1,251		1,209
Operating lease liabilities		918		1,378
Finance lease liabilities		—		5
Total deferred tax assets		70,154		58,765
Valuation allowance		(65,774)		(53,728)
Total deferred tax assets		4,380		5,037

Deferred tax liabilities:
Accrued expenses and other		(3,450)		(3,604)
Fixed assets		(10)		(11)
Operating lease right of use asset		(920)		(1,400)
Finance lease right of use asset		—		(22)
Total deferred tax liabilities		(4,380)		(5,037)

Net deferred tax assets	$	—	$	—

Schedule of changes in the valuation allowance for deferred tax assets


	Year ended December 31,
	2022		2021		2020
Valuation allowance at beginning of period	$	(53,728)	$	(46,064)	$	(32,583)
Increases		(12,046)		(7,664)		(13,481)
Valuation allowance at end of period	$	(65,774)	$	(53,728)	$	(46,064)

Net loss per share (Tables)

12 Months Ended

Dec. 31, 2022

Net loss per share

Schedule of basic and diluted net loss per share

The following table sets forth the computation of the basic and diluted net loss per share attributable to common stockholders (in thousands, except for per share amounts):


	Year ended December 31,
	2022		2021		2020
Numerator:
Net loss	$	(64,915)	$	(75,665)	$	(44,082)

Denominator:
Weighted-average common shares outstanding, basic and diluted		50,743,080		29,945,954		25,876,376
Weighted-average Series A convertible preferred shares outstanding, basic and diluted, presented as if converted into common stock⁽¹⁾		1,697,000		2,887,636		162,732
Weighted-average Series A-1 convertible preferred shares outstanding, basic and diluted, presented as if converted into common stock⁽¹⁾		13,072,877		—		—
Total number of shares used to calculate net loss per share, basic and diluted		65,512,957		32,833,590		26,039,108

Net loss per share, basic and diluted	$	(0.99)	$	(2.30)	$	(1.69)

Schedule of potentially dilutive securities that were not included in the diluted per share calculations


	Year ended December 31,
	2022	2021	2020
Options issued and outstanding	6,532,523	4,231,178	3,555,945
Unvested restricted stock units	—	—	43,700
Total	6,532,523	4,231,178	3,599,645

Summary of significant accounting policies - Going concern (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Summary of significant accounting policies
Net losses	$ (64,915)	$ (75,665)	$ (44,082)
Accumulated deficit	$ (287,681)	$ (222,766)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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+ Details

Summary of significant accounting policies - Property and equipment (Details)	12 Months Ended
	Dec. 31, 2022
Laboratory equipment \| Minimum
Property and equipment
Estimated useful life (in years)	2 years
Laboratory equipment \| Maximum
Property and equipment
Estimated useful life (in years)	10 years
Furniture and fixtures \| Minimum
Property and equipment
Estimated useful life (in years)	2 years
Furniture and fixtures \| Maximum
Property and equipment
Estimated useful life (in years)	10 years
Computer equipment and software \| Minimum
Property and equipment
Estimated useful life (in years)	2 years
Computer equipment and software \| Maximum
Property and equipment
Estimated useful life (in years)	4 years

Summary of significant accounting policies - Others (Details) $ in Millions	12 Months Ended
	Dec. 31, 2022 USD ($) item Program	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Summary of significant accounting policies
Amortization expense \| $	$ 0.1
Impairment losses on long-lived assets \| $	$ 0.0	$ 0.0	$ 0.0
Number of preclinical research programs \| Program	2
Number of Combined Performance Obligation \| item	1
Number of combined performance obligation for each research program \| item	1
Number of research program performance obligations \| item	2
Maximum
Summary of significant accounting policies
Amortization expense \| $		$ 0.1

Summary of significant accounting policies - Comprehensive loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Summary of significant accounting policies
Foreign currency translation (loss)/gain	$ (2,376)	$ 1,287	$ (1,414)

Collaboration and Licensing Agreements (Details) $ in Thousands	1 Months Ended			12 Months Ended
	Oct. 31, 2022 USD ($) item	Dec. 31, 2021 USD ($)	Jun. 30, 2018 USD ($) item	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Collaboration and Licensing Agreements
Deferred revenues		$ 5,538		$ 15,684	$ 5,538
Gilead Collaboration and License Agreement
Collaboration and Licensing Agreements
Number of preclinical research programs \| item			2
Upfront payment received			$ 10,000
Program initiation fee			$ 15,000
Payment term (in days)			60 days
Milestone payment received			$ 8,000
Milestone payments included in deferred revenues		4,000			4,000
Percentage of upfront payment included in deferred revenue expected to be recognized in 2023				29.00%
Percentage of upfront payment included in deferred revenue expected to be recognized in 2024				34.00%
Percentage of upfront payment included in deferred revenue expected to be recognized in 2025				25.00%
Percentage of upfront payment included in deferred revenue expected to be recognized in 2026				12.00%
Cost reimbursements for research and development services included in deferred revenues		1,200		$ 0	1,200
Revenue recognized from upfront payment						$ 4,400
Revenue recognized from milestone payments		0		3,700	2,100
Revenue recognized from cost reimbursements for research and development services				5,200	16,300	13,000
Revenue recognized from milestone payments for milestones achieved				5,000		$ 2,200
Contract asset relating to the sublicense payment		300		200	300
Contract liability relating to sublicense payment		300		0	300
Deferred revenues		$ 4,300			$ 4,300
Deferred income				$ 14,300
Roche collaboration agreement
Collaboration and Licensing Agreements
Upfront payment received	$ 25,000
Percentage of upfront payment included in deferred revenue expected to be recognized in 2023				43.00%
Percentage of upfront payment included in deferred revenue expected to be recognized in 2024				17.00%
Percentage of upfront payment included in deferred revenue expected to be recognized in 2025				16.00%
Percentage of upfront payment included in deferred revenue expected to be recognized in 2026				15.00%
Percentage of upfront payment included in deferred revenue expected to be recognized in 2027				9.00%
Revenue recognized from upfront payment				$ 300
Contract asset relating to the sublicense payment				1,500
Contract liability relating to sublicense payment				1,200
Deferred revenues				$ 27,000
Roche collaboration agreement \| Minimum
Collaboration and Licensing Agreements
Payment term (in days)	30 days
Roche collaboration agreement \| Maximum
Collaboration and Licensing Agreements
Payment term (in days)	60 days
CTA program
Collaboration and Licensing Agreements
Additional payments on exercise of option	$ 15,000
Event based milestone payments	$ 173,000
Number of oncology indications \| item	4
Sales based milestone payments	$ 160,000
HB 700 program
Collaboration and Licensing Agreements
Event based milestone payments	$ 335,000
Number of oncology indications \| item	4
Sales based milestone payments	$ 250,000
Development Milestones \| HBV program
Collaboration and Licensing Agreements
Total milestone amount			140,000
Development Milestones \| HIV program
Collaboration and Licensing Agreements
program completion fee			10,000
Development Milestones \| HIV program \| Maximum
Collaboration and Licensing Agreements
Total milestone amount			172,500
Commercial Milestones \| HBV program
Collaboration and Licensing Agreements
Total milestone amount			50,000
Commercial Milestones \| HIV program
Collaboration and Licensing Agreements
Total milestone amount			$ 65,000

Fair Value of Financial Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Fair Value of Financial Assets
Transfers from Level 1 to Level 2	$ 0
Transfers from Level 2 to Level 1	0
Transfers from into Level 3	0
Transfers from out of Level 3	0
Recurring
Fair Value of Financial Assets
Total	85,491	$ 35,403
Recurring \| Money market funds
Fair Value of Financial Assets
Cash equivalents	85,491	35,403
Recurring \| Level 1
Fair Value of Financial Assets
Total	85,491	35,403
Recurring \| Level 1 \| Money market funds
Fair Value of Financial Assets
Cash equivalents	$ 85,491	$ 35,403

Property, plant and equipment, net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Property and equipment
Property and equipment, gross	$ 25,749	$ 22,718
Less: Accumulated depreciation	(7,779)	(6,366)
Property and equipment, net	17,970	16,352
Depreciation expense	1,900	2,100	$ 1,700
Land
Property and equipment
Property and equipment, gross	1,959	2,072
Leasehold improvements
Property and equipment
Property and equipment, gross	3,164	3,348
Construction in progress
Property and equipment
Property and equipment, gross	10,567	7,746
Laboratory equipment
Property and equipment
Property and equipment, gross	7,403	7,025
Furniture and fixtures
Property and equipment
Property and equipment, gross	622	651
Computer equipment and software
Property and equipment
Property and equipment, gross	$ 2,034	$ 1,876

Receivable research incentive (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Receivable research incentive
Receivable research incentive	$ 15,479	$ 14,271
Income related to the incentive program recorded as grant income	$ 7,300	$ 8,900	$ 5,800

Leases (Details) - USD ($) $ in Thousands	12 Months Ended
Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Leases
Cash balance maintained to secure a letter of credit associated with a real estate lease	$ 419	$ 425
Presentation of leases in condensed consolidated balance sheets:
Operating lease right-of-use assets	4,006	5,673
Finance lease right-of-use assets		90
Total lease assets	4,006	5,763
Current operating lease liability	$ 1,688	1,682
Current finance lease liability		$ 21
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	Accrued Expenses and Other Current Liabilities.	Accrued Expenses and Other Current Liabilities.
Total current lease liabilities	$ 1,688	$ 1,703
Non-current operating lease liability	$ 2,310	$ 3,911
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other Liabilities, Noncurrent	Other Liabilities, Noncurrent
Total non-current lease liabilities	$ 2,310	$ 3,911
Total lease liabilities	$ 3,998	$ 5,614
Minimum
Leases
Remaining lease term (in years)	1 year
Maximum
Leases
Remaining lease term (in years)	3 years

Leases - Lease costs (Details) - USD ($) $ in Thousands	12 Months Ended
Leases - Lease costs (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Leases
Net lease expenses	$ 1,738	$ 2,510	$ 2,299
Research and development expenses
Leases
Operating lease expenses	1,430	1,910	1,654
Finance lease amortization expenses	89	425	395
General and Administrative Expense
Leases
Operating lease expenses	219	203	376
Finance lease amortization expenses		7	21
Interest expenses
Leases
Interest on finance lease liabilities	$ 0	5	8
Other income (expense)
Leases
Sublease income		$ (40)	$ (155)

Leases - Minimum lease payments (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Operating leases
2023	$ 1,570
2024	1,316
2025	1,174
Total lease payments	4,060
Less: interest	62
Present value of lease liabilities	$ 3,998

Leases - Weighted average remaining lease term and weighted average discount rate (Details) - USD ($) $ in Millions	1 Months Ended
	Dec. 31, 2021	Dec. 31, 2022
Lessee, Lease, Description [Line Items]
Operating lease, Weighted average remaining lease term (in years)	3 years 8 months 12 days	2 years 9 months 18 days
Operating lease, Weighted average discount rate	1.30%	1.30%
Finance lease, Weighted average remaining lease term (in years)	2 months 12 days
Finance lease, Weighted average discount rate	0.40%
Research and development expenses
Lessee, Lease, Description [Line Items]
Lease modification loss	$ 1.0

Accrued expenses and other current liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Accrued expenses and other current liabilities
Salaries and bonuses	$ 4,481	$ 4,754
Social security contributions	267	250
Unearned grant income (current)	300	693
Sublicense fees	1,220	304
Accrued external research and development expenses	3,458	2,165
Accrued external general and administration expenses	898	629
Accrued for property and equipment acquisitions		7
Finance lease liabilities		21
Income taxes	230
Other accruals and liabilities	324	57
Total	$ 11,178	$ 8,880

Loans payable (Details) - USD ($) $ in Thousands	12 Months Ended
Loans payable (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Loans payable
Loans from FFG	$ 2,855	$ 6,074
Unamortized debt discount	(350)	(1,063)
Total loans payable, net	$ 2,505	5,011
Interest rate (as a percent)	0.75%
Principal payment	$ 2,825	0	$ 1,311
Unamortized debt discount	400	1,100
Interest expense	700	900	800
Amortization of debt discount	$ 700	800	700
Estimated market rate	20.00%
Threshold for change in estimated market rate	0.10
Deferred revenues, non-current	$ 25,664	21
Deferred revenues	15,684	5,538
Revenue	14,249	18,448	19,584
Grant
Loans payable
Deferred revenues, non-current	100	400
Deferred revenues	300	700
Revenue	$ 600	$ 800	$ 700

Loans payable - Schedule of aggregate minimum future principal payments (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Long-term Debt, Fiscal Year Maturity [Abstract]
2023	$ 1,721
2024	1,134
Total	$ 2,855

- Definition

Amount, excluding unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

+ References + Details

Common stock, Class A common stock and convertible preferred stock (Details) $ / shares in Units, $ in Thousands			1 Months Ended				2 Months Ended	3 Months Ended	12 Months Ended
	Mar. 04, 2022 USD ($) $ / shares shares	Feb. 15, 2022 USD ($) $ / shares shares	Aug. 31, 2022 shares	Jul. 31, 2022 shares	Dec. 31, 2021 shares	Oct. 31, 2021 shares	Aug. 31, 2022 shares	Dec. 31, 2021 shares	Dec. 31, 2022 USD ($) Vote $ / shares shares	Dec. 31, 2021 USD ($) shares	Dec. 31, 2020 USD ($) $ / shares
Preferred stock, shares authorized					10,000,000			10,000,000	10,000,000	10,000,000
Net proceeds from public offering \| $	$ 70,200
Proceeds from issuance of common stock, net of issuance costs \| $									$ 45,691	$ 203	$ 42,637
Register for resale of common stock		4 months
Common stock
Common stock, shares authorized					100,000,000			100,000,000	200,000,000	100,000,000
Common stock, issued (in shares)					27,383,483			27,383,483	52,317,138	27,383,483
Common stock, outstanding (in shares)					27,383,483			27,383,483	52,317,138	27,383,483
Issuance of common stock	21,700,000
Share Price \| $ / shares	$ 2.00
Number of votes \| Vote									1
Number of shares elected to convert							1,420,215
Class A common stock
Common stock, shares authorized					3,900,000			3,900,000	3,900,000	3,900,000
Common stock, issued (in shares)					3,819,732			3,819,732	2,399,517	3,819,732
Common stock, outstanding (in shares)					3,819,732			3,819,732	2,399,517	3,819,732
Number of common stock issued upon conversion of each share									1
Number of shares elected to convert			650,481	769,734			1,420,215
Series A Convertible Preferred Stock
Preferred stock shares Designated					2,978			2,978	2,978	2,978
Preferred stock, shares issued									1,697
Preferred stock, shares outstanding					1,697			1,697	1,697	1,697
Share Price \| $ / shares											$ 11,750
Number of shares elected to convert					1,226	55		1,281
Series A -1 Convertible Preferred Stock
Preferred stock shares Designated					0			0	15,800	0
Preferred stock, shares issued									15,800
Preferred stock, shares outstanding					0			0	15,800	0
Issuance of common stock	15,800
Share Price \| $ / shares	$ 2,000.00
Series A and Series A-1 convertible preferred stock
Number of common stock issued upon conversion of each share									1,000
Threshold percentage for conversion									9.99%
Liquidation preference per share \| $ / shares									$ 0.001
Common Stock
Shares issued upon conversion of redeemable convertible preferred stock (in shares)								1,281,000
Common Stock \| Common stock
Shares issued upon conversion of redeemable convertible preferred stock (in shares)									1,420,215
Common Stock \| Class A common stock
Shares issued upon conversion of redeemable convertible preferred stock (in shares)									(1,420,215)
Stock Purchase Agreement
Net proceeds from public offering \| $		$ 35,000
Issuance of common stock		1,666,666
Proceeds from issuance of common stock, net of issuance costs \| $		$ 5,000
Share Price \| $ / shares		$ 3.00
Outstanding amount \| $		$ 30,000							$ 30,000
Percentage of premium		30.00%
Stock Purchase Agreement \| Gilead \| Gilead Collaboration and License Agreement
Ownership percentage		19.90%
Stock Purchase Agreement \| Common stock
Share Price \| $ / shares									$ 3.00
Stock Purchase Agreement \| Common Stock \| Common stock
Issuance of common stock									1,666,666

Stock-based compensation - 2018 Stock Option and Grant Plan (Details)	12 Months Ended
	Dec. 31, 2022 installment shares	Dec. 31, 2021 shares
Stock-based compensation
Options outstanding	6,532,523	4,231,178
2018 Stock Option and Grant Plan
Stock-based compensation
Vesting period	4 years
Options outstanding	900,796
2018 Stock Option and Grant Plan \| Vesting upon first anniversary
Stock-based compensation
Percentage of options vesting	25.00%
2018 Stock Option and Grant Plan \| Vesting in equal quarterly installments
Stock-based compensation
Percentage of options vesting	75.00%
Number of quarterly installments for vesting \| installment	12

Stock-based compensation - 2019 Stock Option and Incentive Plan (Details)	12 Months Ended
	Dec. 31, 2022 installment shares
Stock-based compensation
Number of common stock entitled for each option upon the exercise of the option \| shares	1
2019 Stock Option and Incentive Plan
Stock-based compensation
Number stock option authorized \| shares	5,878,814
Number of shares outstanding were cumulatively increased	4.00%
Vesting period	4 years
2019 Stock Option and Incentive Plan \| Non Executive Directors
Stock-based compensation
Vesting period	3 years
2019 Stock Option and Incentive Plan \| Vesting upon first anniversary
Stock-based compensation
Percentage of options vesting	25.00%
2019 Stock Option and Incentive Plan \| Vesting upon first anniversary \| Non Executive Directors
Stock-based compensation
Percentage of options vesting	33.00%
2019 Stock Option and Incentive Plan \| Vesting in equal quarterly installments
Stock-based compensation
Percentage of options vesting	75.00%
Number of quarterly installments for vesting \| installment	12
2019 Stock Option and Incentive Plan \| Vesting in equal quarterly installments \| Non Executive Directors
Stock-based compensation
Percentage of options vesting	67.00%
Number of quarterly installments for vesting \| installment	8

Stock-based compensation - Stock option valuation (Details)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Assumptions used in the Black-Scholes option-pricing model
Risk-free interest rate	3.09%	1.07%	0.44%
Expected term (in years)	6 years	6 years 1 month 6 days	6 years 1 month 6 days
Expected volatility	85.40%	85.50%	80.20%

Stock-based compensation - Stock option activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Number of Shares
Beginning balance	4,231,178
Granted	2,709,523
Exercised	(34,223)
Forfeited	(373,955)
Ending balance	6,532,523	4,231,178
Option exercisable	3,182,724
Option unvested	3,349,799
Weighted Averaged Exercise Price
Beginning balance	$ 9.21
Granted	1.55
Exercised	0.10
Forfeited	7.31
Ending balance	6.19	$ 9.21
Option exercisable	8.47
Option unvested	$ 4.01
Weighted Average Remaining Contractual Term
Weighted Average Remaining Contractual Term (in years)	7 years 8 months 12 days	7 years 6 months
Weighted Average Remaining Contractual Term, option exercisable	6 years 3 months 18 days
Weighted Average Remaining Contractual Term, option unvested	9 years
Aggregate Intrinsic Value, beginning balance	$ 1,640
Aggregate Intrinsic Value, ending balance	490	$ 1,640
Aggregate Intrinsic Value, option exercisable	489
Aggregate Intrinsic Value, option unvested	$ 1
Fair value per common stock used for calculating intrinsic values	$ 0.81	$ 2.33	$ 11.09
Aggregate Intrinsic Value, options exercised	$ 100	$ 1,000	$ 2,900
Weighted average grant-date fair value per share of stock options granted	$ 1.55	$ 11.46	$ 8.95
Total fair value of stock options vested	$ 7,900	$ 6,000
Cash received from option exercise under share-based payment arrangements	$ 3	$ 203	$ 63

Stock-based compensation - Restricted Stock Units (Details)	Dec. 31, 2020 shares
Restricted stock units
Stock-based compensation
Number of restricted stock units granted	43,700

Stock-based compensation - Common Stock Awards (Details) - Common Stock Awards - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Stock-based compensation
Share Price		$ 3.00
Share-based awards granted		112,551	0	36,249
Aggregate fair value of share-based awards granted	$ 0.2
Grant date fair value per share	$ 1.50

Stock-based compensation - Stock-based compensation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Stock-based compensation
Stock-based compensation expense	$ 5,043	$ 7,644	$ 8,657
Unrecognized compensation cost related to the unvested stock-based awards	$ 4,700
Weighted average periods over which expense is expected to be recognized	1 year 6 months
Research and development expenses
Stock-based compensation
Stock-based compensation expense	$ 2,074	3,200	3,084
General and Administrative Expense
Stock-based compensation
Stock-based compensation expense	$ 2,969	$ 4,444	$ 5,573

Income taxes (Details) - USD ($) $ in Thousands	12 Months Ended
Income taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income taxes
Income tax benefits for the net operating losses incurred	$ 0	$ 0	$ 0
U.S. federal statutory income tax rate	21.00%	21.00%	21.00%
Increase in tax rate differences	4.00%	4.00%	4.00%
Increase in non-taxable research subsidies received	3.80%	3.80%	4.70%
Increase in non-taxable stock-based compensation	(0.50%)	1.50%	1.00%
Reduction in change in deferred tax asset valuation allowance	27.10%	30.20%	30.20%

Income taxes - Losses before income taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income taxes
United States	$ (7,222)	$ (11,403)	$ (11,603)
Foreign (Austria)	(57,463)	(64,261)	(32,479)
Net loss before tax	$ (64,685)	$ (75,664)	$ (44,082)
Company's worldwide effective tax rate	0.30%	0.00%	0.00%

- Definition

Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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-Section 50
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
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-Section 50
-Paragraph 30
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
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-Section 50
-Paragraph 32
-Subparagraph (f)
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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-Section 25
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
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-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8736-108599

Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(10))
-URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227

Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
-Topic 944
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(8))
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-05(b)(2))
-URI https://asc.fasb.org/extlink&oid=120399901&loc=d3e537907-122884

Reference 9: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
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-Section 50
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Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(15))
-URI https://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

+ Details

Income taxes - components of the consolidated income tax provision (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Current
Federal	$ 217
State	12
Foreign (Austria)	1	$ 1	$ 0
Total current tax expense	230	1	0
Deferred
Total income tax expense	$ 230	$ 1	$ 0

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References + Details

Income taxes - Effective income tax reconciliation (Details)	12 Months Ended					24 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021
Operating Loss Carryforwards [Line Items]
U.S. federal statutory income tax rate			(21.00%)	(21.00%)	(21.00%)
Foreign tax rate differential			(4.00%)	(4.00%)	(4.00%)
Not taxable government grants			(3.80%)	(3.80%)	(4.70%)
Stock-based compensation			0.50%	(1.50%)	(1.00%)
Global intangible low-taxed income			1.40%			0.00%
Other			0.10%	0.10%	0.50%
Change in deferred tax asset valuation allowance			27.10%	30.20%	30.20%
Effective income tax rate			0.30%	0.00%	0.00%
Austria
Operating Loss Carryforwards [Line Items]
U.S. federal statutory income tax rate	(23.00%)	(24.00%)	(25.00%)

Income taxes - Components of the net deferred tax assets or liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Net operating loss carryforwards	$ 66,201	$ 55,752
Capitalized R&D expenses	1,354
Credit carryforwards	64	64
Accrued expenses and other	366	357
Stock-based compensation	1,251	1,209
Operating lease liabilities	918	1,378
Finance lease liabilities		5
Total deferred tax assets	70,154	58,765
Valuation allowance	(65,774)	(53,728)	$ (46,064)	$ (32,583)
Total deferred tax assets	4,380	5,037
Deferred tax liabilities:
Accrued expenses and other	(3,450)	(3,604)
Fixed assets and intangible assets	(10)	(11)
Operating lease right of use asset	(920)	(1,400)
Finance lease right of use asset		(22)
Total deferred tax liabilities	$ (4,380)	$ (5,037)

Income taxes - Changes in the valuation allowance for deferred tax assets and others (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2026	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating Loss Carryforwards [Line Items]
Corporate income tax rate				21.00%	21.00%	21.00%
Valuation allowance at beginning of period			$ (65,774)	$ (53,728)	$ (46,064)	$ (32,583)
Increases				(12,046)	(7,664)	(13,481)
Valuation allowance at end of period				$ (65,774)	(53,728)	(46,064)
Threshold return percentage of GILIT				10.00%
Reduction percentage of inclusion for GILTI				50.00%
Percentage of inclusion for GILTI	37.50%
Global Intangible Low Taxed Income Recognized				$ 3,600	0
Unrecognized income tax benefits				0	0
Federal
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards				$ 13,800	17,900	8,300
Austria
Operating Loss Carryforwards [Line Items]
Corporate income tax rate		23.00%	24.00%	25.00%
Net operating loss carryforwards				$ 275,300	$ 219,700	$ 163,200

Commitments and contingencies - Others (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Commitments and contingencies
Non-cancellable obligations	$ 9.3
2023 deliverables	9.2
2024 deliverables	0.1
Licensing fees from intellectual property licenses	$ 1.0	$ 1.3	$ 1.2

401(k) Savings Plan (Details) - USD ($) $ in Millions	12 Months Ended
401(k) Savings Plan (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Contribution Plan Disclosure [Line Items]
Expenses recognized for the 401(k) Plan	$ 0.6	$ 0.4	$ 0.2
Maximum
Defined Contribution Plan Disclosure [Line Items]
Matching contribution to defined contribution savings plan	100.00%
Employer's Matching contribution to defined contribution savings plan	4.00%

Net loss per share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Numerator:
Net loss	$ (64,915)	$ (75,665)	$ (44,082)
Denominator:
Weighted-average common shares outstanding, basic and diluted	50,743,080	29,945,954	25,876,376
Weighted-average Series A convertible preferred shares outstanding, basic and diluted, presented as if converted into common stock	1,697,000	2,887,636	162,732
Weighted-average Series A-1 convertible preferred shares outstanding, basic and diluted, presented as if converted into common stock	13,072,877
Total number of shares used to calculate net loss per share, basic	65,512,957	32,833,590	26,039,108
Total number of shares used to calculate net loss per share, diluted	65,512,957	32,833,590	26,039,108
Net loss per share - basic	$ (0.99)	$ (2.30)	$ (1.69)
Net loss per share - diluted	$ (0.99)	$ (2.30)	$ (1.69)
Class A common stock
Denominator:
Number of shares issued for each share of common stock	1
Number of common shares issuable upon conversion of common stock	2,399,517
Series A Convertible Preferred Stock
Denominator:
Number of common stock issued upon conversion of each share of Preferred Stock	1,000
Number of common stock issuable upon conversion of convertible preferred stock	1,697,000
Series A -1 Convertible Preferred Stock
Denominator:
Number of common stock issued upon conversion of each share of Preferred Stock	1,000
Number of common stock issuable upon conversion of convertible preferred stock	15,800,000

Net loss per share - Antidilutive securities (Details) - shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Anti-dilutive securities
Anti-dilutive shares	6,532,523	4,231,178	3,599,645
Options
Anti-dilutive securities
Anti-dilutive shares	6,532,523	4,231,178	3,555,945
Restricted stock units
Anti-dilutive securities
Anti-dilutive shares			43,700

Related parties (Details) - University of Basel - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Related parties
Royalties paid	$ 0.0	$ 0.0	$ 0.0
Research and development expenses
Related parties
Service fees paid			$ 0.3