F-star Therapeutics (FSTX) 10-K 30 Mar 21 2020 FY Annual report Financial data

Cover Page

Cover Page - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Mar. 24, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Trading Symbol	FSTX
Title of 12(b) Security	Common Stock, $0.0001 par value
Security Exchange Name	NASDAQ
Entity Registrant Name	F-star Therapeutics, Inc.
Entity Central Index Key	0001566373
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Voluntary Filers	No
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Shell Company	false
Document Annual Report	true
Document Transition Report	false
Entity File Number	001-37718
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	52-2386345
Entity Address, Address Line One	B920 Babraham Research Campus
Entity Address, City or Town	Cambridge
Entity Address, Postal Zip Code	CB22 3AT
Entity Address, Country	GB
City Area Code	44
Local Phone Number	1223-497400
Entity Public Float			$ 23.4
Entity Common Stock, Shares Outstanding		9,100,320
Documents Incorporated by Reference	Portions of such definitive proxy statement are incorporated by reference into Part III of this Annual Report on Form 10-K to the extent stated herein.
ICFR Auditor Attestation Flag	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 18,526	$ 4,901
Prepaid expenses and other current assets	3,976	3,588
Tax incentive receivable Current	3,563	10,532
Total current assets	26,065	19,021
Property and equipment, net	789	1,425
Right of use asset	2,782	607
Goodwill	14,926	4,320
In-process research and development	18,986	13,049
Other long-term assets	61	56
Total	63,609	38,478
Current liabilities:
Accounts payable	4,597	5,056
Accrued expenses and other current liabilities	9,461	8,876
Contingent value rights	2,080	0
Lease obligations, current	539	610
Deferred revenue	300	442
Convertible term loan	0	14,906
Total current liabilities	16,977	29,890
Lease obligations	2,622	52
Contingent value rights	440	0
Deferred tax liability	576	0
Total liabilities	20,615	29,942
Stockholders' equity:
Preferred stock	0	0
Common Stock, $0.0001 par value; authorized 200,000,000 shares at December 31, 2020 and December 31, 2019; 9,100,117 and 4,128,441 shares issues and outstanding at December 31, 2020 and 2019	1	1
Additional paid-in capital	91,238	31,718
Accumulated other comprehensive loss	(1,077)	(1,634)
Accumulated deficit	(47,168)	(21,549)
Total stockholders' equity	42,994	8,536
Total	63,609	38,478
Seed Preferred Shares [Member]
Stockholders' equity:
Preferred stock	0	0
Series A Preferred Stock [Member]
Stockholders' equity:
Preferred stock	$ 0	$ 0

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2020
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	4,128,441	9,100,117
Common stock, shares outstanding	4,128,441	9,100,117
Seed Preferred Shares [Member]
Preferred Stock, Shares Authorized, Unlimited [Fixed List]	Unlimited
Preferred stock, par value	$ 0.00759446
Preferred stock, shares issued	103,611
Preferred stock, shares outstanding	103,611
Series A Preferred Stock [Member]
Preferred Stock, Shares Authorized, Unlimited [Fixed List]	Unlimited
Preferred stock, par value	$ 0.00759446
Preferred stock, shares issued	1,441,418
Preferred stock, shares outstanding	1,441,418

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
License revenue	$ 11,256	$ 28,321
Operating expenses:
Research and development	14,128	31,386
General and administrative	19,513	15,280
Impairment on intangible assets	0	4,152
Total operating expenses	33,641	50,818
Loss from operations	(22,385)	(22,497)
Other non-operating (expense)income:
Other (expense) income	(849)	197
Change in fair value of convertible debt	(2,386)	(1,450)
Loss before income taxes	(25,620)	(23,750)
Income tax benefit	1	737
Net loss	(25,619)	(23,013)
Net loss attributable to common stockholders	$ (25,619)	$ (23,013)
Basic and diluted adjusted net loss per common shares	$ (9.69)	$ (14.89)
Weighted-average number of common shares outstanding, basic and diluted	2,643,175	1,545,177
Other comprehensive gain (loss):
Net loss	$ (25,619)	$ (23,013)
Foreign currency translation	557	(1,246)
Total comprehensive loss	$ (25,062)	$ (24,259)

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Capital in Excess of par Value	Common Shares	Accumulated Other Comprehensive Loss	Retained Earnings (Accumulated deficit)	Additional Paid-in Capital [Member]	Seed Preferred Shares [member]	Series A Preferred Stock [member]	GMBH One [member]	GMBH One [member]Capital in Excess of par Value	GMBH Two [member]	GMBH Two [member]Capital in Excess of par Value	GMBH Three [member]	GMBH Three [member]Capital in Excess of par Value	Delta [member]	Delta [member]Capital in Excess of par Value	Beta [member]	Beta [member]Capital in Excess of par Value	Spring Bank [member]	Spring Bank [member]Capital in Excess of par Value	Spring Bank [member]Common Shares	Spring Bank [member]Seed Preferred Shares [member]	Spring Bank [member]Series A Preferred Stock [member]	Alpha [member]	Alpha [member]Capital in Excess of par Value
Balance at Dec. 31, 2018	$ 1,077		$ 1	$ (388)	$ 1,464
Balance, shares at Dec. 31, 2018			4,108,654
Issuance of shares for acquisition, Share							103,611	1,441,418
Issuance of shares for acquisition									$ 169	$ 169	$ 2,360	$ 2,360	$ 206	$ 206	$ 14,823	$ 14,823	$ 10,556	$ 10,556						$ 935	$ 935
Issuance of common stock for services rendered, shares			19,637
Issuance of common stock in connection with at-the-market offering, shares			150
Equity adjustment from foreign currency translation	(1,246)			(1,246)
Stock-based compensation	2,669	$ 2,669
Net loss	(23,013)				(23,013)										$ 4,800
Balance at Dec. 31, 2019	8,536	31,718	$ 1	(1,634)	(21,549)
Balance, shares at Dec. 31, 2019			4,128,441				103,611	1,441,418
Purchase of fractional shares			(242)
Issuance of shares for acquisition, Share																					4,620,618	103,611	1,441,418
Issuance of shares for acquisition	55,781																			$ 55,781
Issuance of common stock pursuant to vesting of restricted stock units, shares			133,000
Issuance of common stock for services rendered, shares			15,636
Issuance of common stock in connection with at-the-market offering, shares			172,724
Issuance of ordinary shares for professional services	250	$ 250
Issuance of ordinary shares for professional services, shares			29,940
Equity adjustment from foreign currency translation	557			557
Stock-based compensation	3,489					$ 3,489
Net loss	(25,619)				(25,619)														$ 1,700
Balance at Dec. 31, 2020	$ 42,994		$ 1	$ (1,077)	$ (47,168)	$ 91,238
Balance, shares at Dec. 31, 2020			9,100,117

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net loss		$ (25,619)	$ (23,013)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Share based compensation expense		3,489	2,669
Foreign currency loss		338	81
Loss on disposal of tangible fixed assets		7	14
Depreciation		1,144	844
Intangible asset impairment		0	4,152
Interest expense		1,002	197
Fair value adjustment of convertible term loan		2,386	1,450
Changes in operating assets and liabilities:
Prepaid expenses and other current assets		621	322
Tax incentive receivable		6,944	(5,883)
Accounts payable		(2,847)	3,049
Accounts payable to related parties			(789)
Accrued expenses and other liabilities		(2,890)	1,525
Deferred revenue		(149)	(6,350)
Operating lease liabilities		(652)	(379)
Net cash used in by operating activities		(16,226)	(22,111)
Cash flows from investing activities:
Cash acquired with transaction		9,779
Cash acquired with subsidiaries*	[1]		5,499
Proceeds from sale of marketable securities		5,000	0
Purchase of intangible assets		(730)	(127)
Net cash provided by investing activities		14,049	5,372
Cash flows from financing activities:
Proceeds from issuance of convertible notes		850	13,264
Proceeds from private placement		15,000
Net cash provided by financing activities		15,850	13,264
Net increase (decrease) in cash, cash equivalents and restricted cash		13,673	(3,475)
Effect of exchange rate changes on cash		(48)	180
Cash and cash equivalents at beginning of year		4,901	8,196
Cash and cash equivalents at end of year		18,526	4,901
Supplemental disclosures of cash flow information:
Cash paid for taxes		124	249
Cash paid for amounts included in the measurement of operating lease		662	$ 380
Supplemental disclosure of non-cash information
Fair value of net assets acquired		$ 21,536
[1]	Consideration for acquisition of subsidiaries was entirely in the form of issued shares. See note 5 for supplemental disclosure of assets and liabilities acquired with subsidiaries.

Nature of the business

Nature of the business	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of the business	1. Nature of the business F-star ™ Share Exchange Agreement On November 20, 2020, F-star Therapeutics, F-star”), F-star Therapeutics Limited (“F-star Company, F-star Ltd of F-star Ltd of F-star Ltd of F-star Ltd of F-star Ltd such F-star Ltd and non-assessable a 1-for-4 reverse to “F-star Therapeutics, F-star Under the terms of the Exchange Agreement, at the Closing, Spring Bank issued an aggregate of 4,620,618 shares of its common stock to F-star Ltd each F-star and F-star Ltd Pursuant to the Exchange Agreement, immediately prior to the Closing, certain investors in F-star Ltd of F-star (the “Pre-Closing Financing”). of F-star Ltd Pursuant to the Exchange Agreement, all outstanding options to purchase Spring Bank common stock were accelerated immediately prior to the Closing and each outstanding option with an exercise price greater than the closing price of the stock on the Closing Date was exercised in full and all other outstanding options to purchase Company common stock were cancelled effective as of the Closing Date. Immediately following the Reverse Stock Split and the Closing, there were approximately shares of Spring Bank common stock outstanding. Following the Closing, the F-star Ltd stockholders beneficially owned approximately and F-star Ltd of F-star Ltd into lock-up agreements (the “Lock-up Agreements”), the 180-day period of F-star Ltd the Pre-Closing Financing In addition, at the Closing, Spring Bank, F-star pre-Reverse pre-Reverse The CVR payment obligation expires on the later of 18 months following the Closing or the one-year anniversary At the Closing, Spring Bank, F-star The CVR payment obligations expire on the seventh anniversary of the Closing (the “STING Antagonist CVR Expiration Date”). The STING Antagonist CVRs are not transferable, except in certain limited circumstances, are not certificated or evidenced by any instrument, do not accrue interest and are not registered with the SEC or listed for trading on any exchange. Until the STING Antagonist CVR Expiration Date, subject to certain exceptions, the Company is required to use commercially reasonable efforts to (a) consummate the Approved Development Agreement to the extent not entered into prior to Closing, (b) to perform the terms of the Approved Development Agreement and (c) pursue CVR Transactions. Unless terminated earlier in accordance with its terms, the STING Antagonist CVR Agreement became effective upon the Closing and will continue in effect until the STING Antagonist CVR Expiration Date or all CVR payment amounts are paid pursuant to its terms. The acquisition-date fair value of the contingent valuation rights liability represents the future payments that are contingent upon the achievement of sale or licencing for the product candidates. The fair value of the contingent consideration assumed of $2.5 million as of December 31, 2020 is based on the Company’s probability-weighted discounted cash flow assessment that considers probability and timing of future payments. The fair value measurement is based on significant Level 3 unobservable inputs such as the probability of achieving a sale or licensing agreement, anticipated timelines and discount rate. Changes in the fair value of the liability will be recognized in the consolidated statement of operations and comprehensive loss until settlement. At the Closing, all issued share options and restricted stock units granted by F-star Ltd F-star Therapeutics The Company’s common stock, which was listed on the Nasdaq Capital Market, traded through the close of business on Friday, November 20, 2020 under the ticker symbol “SBPH” and continued trading on the Nasdaq Capital Market, on a post-Reverse Stock Split adjusted basis, under the ticker symbol “FSTX” beginning on Monday, November 23, 2020. Commencing on November 23, 2020, the Company’s common stock was represented by a new CUSIP number, 30315R 107. After the Transaction, the Company had approximately $30 million in cash. The combined company is now headquartered out of F-star The Transaction was accounted for as a business combination using the acquisition method of accounting under the provisions of Financial Accounting Standards Board, Accounting Standards Codification (“ASC 805”), Topic 805 “Business Combinations” (“ASC 805”). The Transaction was accounted for as a reverse acquisition with F-star F-star Ltd F-star (1) F-star (2) F-star (3) F-star F-star of the combined organization. 2019 reorganization On May 7, 2019, F-star of F-star Delta (“Delta”), F-star Beta (“Beta”), F-star Biotechnologische Forschungs-und Entwicklungsges.m.b.H. and F-star Alpha the “F-star Group The shareholdings in the F-star Group F-star F-star 1. The shareholders in Delta transferred their shares to F-star F-star 2. The shareholders in Beta, GmbH and Alpha transferred their shares to F-star F-star F-star the F-star Group the F-star Group The primary reason for the 2019 reorganization was to bring the F-star Ltd of F-star Risks and Uncertainties The Company is subject to risks common to companies in the biotechnology industry, including but not limited to, risks of failure of preclinical studies and clinical trials, the need to obtain marketing approval for any drug product candidate that it may identify and develop, the need to successfully commercialize and gain market acceptance of its product candidates, dependence on key personnel and collaboration partners, protection of proprietary technology, compliance with government regulations, development by competitors of technological innovations, and the ability to secure additional capital to fund operations. Product candidates currently under development will require significant additional research and development efforts, including preclinical and clinical testing and regulatory approval prior to commercialization. Even if the Company’s research and development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales. The accompanying consolidated financial statements have been prepared on the basis of continuity of operations, realization of assets and the satisfaction of liabilities and commitments in the ordinary course of business. Since inception, the Company has devoted substantially all of its efforts to business planning, research and development, clinical expenses, recruiting management and technical staff, and securing funding via collaborations. The Company has historically funded its operations with proceeds received from its collaboration arrangements, sale of equity capital and proceeds from sales of convertible notes. The Company had approximately $18.5 million in cash as of December 31, 2020. The Company expects to continue to generate operating losses in the foreseeable future, particularly as the Company advances its preclinical activities and clinical trials for its product candidates in development. The Company plans to seek additional funding through public equity, private equity, debt financing, collaboration partnerships, or other sources. There are no assurances, however, that the Company will be successful in these endeavors. If the Company is unable to obtain funding, the Company could be forced to delay, reduce, or eliminate its research and development programs, or reduce product candidate expansion, which could adversely affect its business prospects. Although management continues to pursue its funding plans, there is no assurance that the Company will be successful in obtaining sufficient funding to fund continuing operations on terms acceptable to the Company , if at all. Accordingly, the Company has concluded that substantial doubt exists about the Company’s ability to continue as a going concern for a period of at least twelve months from the date of the financial statements. Impact of Covid-19 In March 2020, the World Health Organization declared the novel strain of coronavirus (COVID-19) a worldwide. The COVID-19 pandemic has evolving, and to date has led to the implementation of various responses, including government-imposed quarantines, travel restrictions and other public health safety measures. Management continues to closely monitor the impact of the COVID-19 pandemic on to which COVID-19 impacts of COVID-19 or the to contain COVID-19 or treat emerge concerning COVID-19 and the Management have not identified any triggering events which would result in any significant impairment losses in the carrying values of assets as a result of the pandemic and are not aware of any specific related event or circumstance that would require management to revise estimates reflected in these consolidated financial statements.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The Company’s financial statements have been prepared in conformity with generally accepted accounting principles in the United States of America (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”). The accompanying consolidated financial statements include the accounts of F-star F-star (F-star F-star F-star F-star F-star f-star Forschungs-und F-star All intercompany balances and transactions between the consolidated companies have been eliminated in consolidation. 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 consolidated financial statements and the reported amounts of expenses during the reporting years. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, the fair value of the assets and liabilities acquired in the transaction between Spring Bank and F-star Foreign currency and currency translation The functional currency is the currency of the primary economic environment in which an entity’s operations are conducted. The Company and its subsidiaries operate mainly in the United Kingdom, United States and Austria. The Company’s reporting currency is the U.S dollar. The Company translates the assets and liabilities of its subsidiaries into U.S. dollar at the exchange rate in effect on the balance sheet date. Revenues and expenses are translated at the average exchange rate in effect during each monthly period. Unrealized translation gains and losses are recorded as a cumulative translation adjustment, which is included in the consolidated statements of shareholders’ equity as a component of accumulated other comprehensive (loss)income. Translation differences resulting from the conversion from functional currency to reporting currency are included as part of the cumulative foreign currency translation adjustment, which is reported as a component of shareholders’ equity under accumulated other comprehensive loss. Monetary assets and liabilities denominated in currencies other than the functional currency are remeasured into the functional currency at rates of exchange prevailing at the balance sheet dates. Non-monetary Adjustments that arise from exchange rate changes on transactions denominated in a currency other than the local currency are included in other (expense) income in the consolidated statements of operations and comprehensive loss as incurred. The Company recorded a foreign exchange loss of $0.4 million and a gain of $0.3 million included in other (expense) income in the consolidated statement of operations and comprehensive loss for the years ended December 31, 2020, and 2019, respectively. Emerging Growth Company Section 102(b)(1) of the Jumpstart Our Business Startups Act of 2012 (the “JOBS Act”) exempts emerging growth companies from being required to comply with new or revised financial accounting standards until private companies (that is, those that have not had a Securities Act registration statement declared effective or do not have a class of securities registered under the Exchange Act) are required to comply with the new or revised financial accounting standards. The JOBS Act provides that an emerging growth company can elect to opt out of the extended transition period and comply with the requirements that apply to non-emerging Concentrations of credit risk and of significant suppliers Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash and cash equivalents. The Company maintains its cash and cash equivalents in financial institutions in amounts that could exceed government-insured limits. The Company does not believe it is subject to additional credit risks beyond those normally associated with commercial banking relationships. The Company is dependent on third-party manufacturers to supply products for research and development activities in its programs. In particular, the Company relies and expects to continue to rely on a small number of manufacturers to supply its requirements for supplies and raw materials related to these programs. These programs could be adversely affected by a significant interruption in these manufacturing services or the availability of raw materials. Cash and cash equivalents The Company considers all highly liquid investments with original maturities of three months or less at date of purchase to be cash equivalents. The Company had no cash equivalents on December 31, 2020, and 2019. Property, plant and equipment Property, plant and equipment are stated at cost, less accumulated depreciation . Depreciation expense is recognized using the straight-line method over the estimated useful lives of the respective assets as follows: Estimated Useful Economic Life Leasehold property improvements, right of use assets Lesser of lease term or useful life Laboratory equipment 5 years Furniture and office equipment 3 years Costs for capital assets not yet placed into service are capitalized as construction-in-progress Impairment of long-lived assets Long-lived assets consist of property, plant and equipment, goodwill, and intangible assets. 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 industry or economic trends and significant changes or planned changes in the use of the assets. An impairment loss would be recognized as a loss from operations when estimated undiscounted future cash flows expected to result from the use of an asset group or the estimated return on investment 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 flow or return on investment calculations. The Company recorded an impairment loss on long-lived assets of $4.2 million during the year ended December 31, 2019. Business Combinations and Goodwill Business combinations are accounted for in accordance with ASC Topic 805 “Business Combinations”. The total purchase price of an acquisition is allocated to the underlying identifiable net assets, based on their respective estimated fair values as of the acquisition date. Determining the fair value of assets acquired and liabilities assumed requires management’s judgment and often involves the use of significant estimates and assumptions, including assumptions with respect to future cash inflows and outflows, probabilities of success, discount rates, and asset lives, among other items. Assets acquired and liabilities assumed are recorded at their estimated fair values. The excess of the purchase price over the estimated fair values of the net assets acquired is recorded as goodwill. Goodwill is tested for impairment at the reporting unit level annually in the fourth quarter, or more frequently when events or changes in circumstances indicate that the asset might be impaired. Examples of such events or circumstances include, but are not limited to, a significant adverse change in legal or business climate, an adverse regulatory action or unanticipated competition. The Company has determined that it operates in a single operating segment and has a single reporting unit. To perform its quantitative test, the Company compares the fair value of the reporting unit to its carrying value. If the fair value of the reporting unit exceeds the carrying value of its net assets, goodwill is not impaired, and no further testing is required. If the fair value of the reporting unit is less than the carrying value, the Company measures the amount of impairment loss, if any, as the excess of the carrying value over the fair value of the reporting unit. Required annual testing of goodwill for impairment was completed as of December 31, 20 20 Contingent value rights The acquisition-date fair value of the contingent valuation rights liability represents the future payments that are contingent upon the achievement of sale or licencing for the STING product candidates. The fair value of the contingent value rights is based on the Company’s probability-weighted discounted cash flow assessment that considers probability and timing of future payments. The fair value measurement is based on significant Level 3 unobservable inputs such as the probability of achieving a sale or licensing agreement, anticipated timelines, and discount rate. Changes in the fair value of the liability will be recognized in the consolidated statement of operations and comprehensive loss until settlement. Acquired In-Process Acquired IPR&D represents the fair value assigned to research and development assets that the Company acquires and have not been completed at the acquisition date. The fair value of IPR&D acquired in a business combination is recorded on the consolidated balance sheets at the acquisition-date fair value and is determined by estimating the costs to develop the technology into commercially viable products, estimating the resulting revenue from the projects, and discounting the projected net cash flows to present value. IPR&D is not amortized, but rather is reviewed for impairment on an annual basis or more frequently if indicators of impairment are present, until the project is completed, abandoned or transferred to a third party. The projected discounted cash flow models used to estimate the fair value of partnered assets and cost approach model used to estimate proprietary assets as part of the Company’s IPR&D reflect significant assumptions regarding the estimates a market participant would make in order to evaluate a drug development asset, including the following: • Estimates of obsolescence of development expenditure; • Probability of successfully completing clinical trials and obtaining regulatory approval; • Estimates of future cash flows from potential milestone payments and royalties related to out-licensed • A discount rate reflecting the Company’s weighted average cost of capital and specific risk inherent in the underlying assets. Once brought into use, intangible assets are amortized over their estimated useful economic lives, which for acquired IPR&D assets is over the remaining life of the relevant patents. Fair value measurements of financial instruments The Company’s financial instruments consist of cash, accounts payable, CVR and liability classified warrants. The carrying amounts of cash and accounts payable approximate their fair value due to the short-term nature of those financial instruments. The fair value of CVR and the liability classified warrants are remeasured to fair value each reporting period. 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. Accounting Standards Codification (“ASC”) Topic 820, Fair Value Measurement (“ASC 820”), establishes a fair value hierarchy for instruments measured at fair value that distinguishes between assumptions based on market data (observable inputs) and the Company’s own assumptions (unobservable inputs). Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the inputs that market participants would use in pricing the asset or liability and are developed based on the best information available in the circumstances. ASC 820 identifies fair value as the exchange price, or exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As a basis for considering market participant assumptions in fair value measurements, ASC 820 establishes a three-tier fair value hierarchy that distinguishes between the following: • 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 that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The carrying amounts reflected in the consolidated balance sheets for cash and cash equivalents, and other current assets, research and development incentives receivable, accounts payable and accrued liabilities and other current liabilities approximate their fair values, due to their short-term nature. Segment and geographic information Operating segments are defined as components of a business for which separate discrete financial information is available for evaluation by the chief operating decision maker in deciding how to allocate resources and assess performance. The Company and its chief operating decision maker, the Company’s Chief Executive Officer, view the Company’s operations and manage its business as a single operating segment. The Company operates in three geographic areas: the United Kingdom, United States and Austria. Leases The Company determines if an arrangement is a lease at inception. Operating leases are included in operating lease right-of-use ROU assets represent the Company’s right to use and control an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. ROU assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. As the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. The ROU asset also includes lease payments made before the lease commencement date and excludes any lease incentives. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. The components of a lease shall be split into three categories, if applicable: lease components (e.g., land, building, etc.), non-lease non-components in-substance non-components) non-lease non-lease non-lease right-of-use License and collaboration arrangements and revenue recognition The Company’s revenues are generated primarily through license and collaboration agreements with pharmaceutical and biotechnology companies. The terms of these arrangements may include (i) the grant of intellectual property rights (IP licenses) to therapeutic drug candidates against specified targets, developed using the Company’s proprietary mAb 2 The terms of these arrangements typically include payment to the Company of one or more of the following: non-refundable, The Company has adopted Financial Accounting Standards Board (the “FASB”) Accounting Standards Codification (“ASC”) Topic 606—Revenue from Contracts with Customers (“ASC 606”). This standard applies to all contracts with customers, except for contracts that are within the scope of other standards, such as leases, insurance, collaboration arrangements and financial instruments. To date, the Company has entered into License and Collaboration Agreements with Denali Therapeutics, Inc., and Ares Trading S.A. (an affiliate of Merck KGaA, Darmstadt, Germany) which were determined to be within the scope of ASC 606. Under ASC 606, an entity recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. In determining the appropriate amount of revenue to be recognized under ASC 606, the Company performs the following steps: (i) identify the promised goods or services in the contract; (ii) determine whether the promised goods or services are performance obligations including whether they are distinct in the context of the contract; (iii) measurement of the transaction price, including the constraint on variable consideration; (iv) allocation of the transaction price to the performance obligations; and (v) recognition of revenue when (or as) the Company satisfies each performance obligation. As part of the accounting for these arrangements, the Company must make significant judgments, including identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each performance obligation. Once a contract is determined to be within the scope of ASC 606, the Company assesses the goods or services promised within the contract and determines those that are performance obligations. Arrangements that include rights to additional goods or services that are exercisable at a customer’s discretion are generally considered options. The Company assesses if these options provide a material right to the customer and if so, they are considered performance obligations. Performance obligations are promised goods or services in a contract to transfer a distinct good or service to the customer. The promised goods or services in the Company’s contracts with customers primarily consist of license rights to the Company’s intellectual property for research and development, research and development services, options to acquire additional research and development services, and options to obtain additional licenses, such as a commercialization license for a potential product candidate. Promised goods or services are considered distinct when: (i) the customer can benefit from the good or service on its own or together with other readily available resources; and (ii) the promised good or service is separately identifiable from other promises in the contract. In assessing whether promised goods or services are distinct, the Company considers factors such as the stage of development of the underlying intellectual property, the capabilities of the customer to develop the intellectual property on their own and whether the required expertise is readily available. In addition, the Company considers whether the collaboration partner can benefit from a promise for its intended purpose without the receipt of the remaining promises, whether the value of the promise is dependent on the unsatisfied promises, whether there are other vendors that could provide the remaining promises, and whether it is separately identifiable from the remaining promises. The Company estimates the transaction price based on the amount of consideration the Company expects to receive for transferring the promised goods or services in the contract. The consideration may include both fixed consideration and variable consideration. At the inception of each arrangement that includes variable consideration, the Company evaluates the amount of the potential payments and the likelihood that the payments will be received. The Company utilizes either the most likely amount method or expected value method to estimate variable consideration to include in the transaction price based on which method better predicts the amount of consideration expected to be received. The amount included in the transaction price is constrained to the amount for which it is probable that a significant reversal of cumulative revenue recognized will not occur. At the end of each subsequent reporting period, the Company re-evaluates catch-up After the transaction price is determined it is allocated to the identified performance obligations based on the estimated standalone selling price. The Company must develop assumptions that require judgment to determine the standalone selling price for each performance obligation identified in the contract. The Company utilizes key assumptions to determine the standalone selling price, which may include other comparable transactions, pricing considered in negotiating the transaction, probabilities of technical and regulatory success and the estimated costs. Certain variable consideration is allocated specifically to one or more performance obligations in a contract when the terms of the variable consideration relate to the satisfaction of the performance obligation and the resulting amounts allocated to each performance obligation are consistent with the amounts the Company would expect to receive for each performance obligation. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) each performance obligation is satisfied at a point in time or over time, and if over time based on the use of an input method. The Company accounts for contract modifications as a separate contract if both of the following conditions are met: (i) the scope of the contract increases because of the addition of promised goods or services that are distinct; and (ii) the price of the contract increases by an amount of consideration that reflects standalone selling prices of the additional promised goods or services and any appropriate adjustments to that price to reflect the circumstances of the particular contract. If a contract modification is deemed to not be a separate contract, then the transaction price is updated and allocated to the remaining performance obligations (both from the existing contract and the modification). Previously recognized revenue for goods and services that are not distinct from the modified goods or services is adjusted based upon an updated measure of progress for the partially satisfied performance obligations. If a contract modification is deemed to be a separate contract, any revenue recognized under the original contract is not retrospectively adjusted and any performance obligations remaining under the original contract continue to be recognized under the terms of that contract. The Company’s collaboration revenue arrangements include the following: Up-front up-front non-refundable, up-front Milestone payments: The Company’s collaboration agreements may include development and regulatory milestones. The Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. The Company evaluates factors such as the scientific, clinical, regulatory, commercial, and other risks that must be overcome to achieve the particular milestone in making this assessment. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the Company’s control or the licensee’s control, such as regulatory approvals, are not considered probable of being achieved until those approvals are received. At the end of each reporting period, the Company re-evaluates catch-up Customer Options: The Company evaluates the customer options to obtain additional items (i.e., additional license rights) for material rights, or options to acquire additional goods or services for free or at a discount. Optional future services that reflect their standalone selling prices do not provide the customer with a material right and, therefore, are not considered performance obligations and are accounted for as separate contracts. If optional future services include a material right, they are accounted for as performance obligations. The Company determines an estimated standalone selling price of any material rights for the purpose of allocating the transaction price. The Company considers factors such as the identified discount and the probability that the customer will exercise the option. Amounts allocated to a material right are not recognized as revenue until, at the earliest, the option is exercised or expires. Royalties: For arrangements that include sales-based royalties, including milestone payments based on a level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company will recognize revenue at the later of Research and Development Services: The promises under the Company’s collaboration agreements may include research and development services to be performed by the Company on behalf of the partner. Payments or reimbursements resulting from the Company’s research and development efforts are recognized as the services are performed and presented on a gross basis because the Company is the principal for such efforts. Research and development costs Research and development costs are expensed as incurred. Research and development expenses are comprised of costs incurred in performing research and development activities, including salaries, share-based compensation and benefits, facilities costs and laboratory supplies, depreciation, amortization and impairment expense, manufacturing expenses and external costs of outside vendors engaged to conduct preclinical development activities and clinical trials as well as the cost of licensing technology. Typically, upfront payments and milestone payments made for the licensing of technology are expensed as research and development in the period in which they are incurred, except for payments relating for intellectual property rights with future alternative use which will be expensed when the intellectual property is in use. Nonrefundable 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. Research contract costs and accruals The Company has entered into various research and development contracts with companies both inside and outside of the United States. These agreements are generally cancelable, and related payments are recorded as research and development expenses as incurred. The Company records accruals for estimated ongoing research costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the studies or trials, 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. Research and development incentives and receivable The Company, through its subsidiaries in the United Kingdom, receives reimbursements of certain research and development expenditures as part of a United Kingdom government’s research and development tax reliefs program. Under the program, the Company is able to surrender trading losses that arise from qualifying research and development expenses incurred in the United Kingdom for a tax credit of up to 14.5% of the surrender able losses. Management has assessed the Company’s research and development activities and expenditures to determine which activities and expenditures are likely to be eligible under the research and development incentive program described above. At each period end, management estimates the reimbursement available to the Company based on available information at the time. The Company recognizes income from the research and development incentives when the relevant expenditure has been incurred, the associated conditions have been satisfied and there is reasonable assurance that the reimbursement will be received. The Company records these research and development incentives as a reduction to research and development expenses in the consolidated statements of operations and comprehensive loss, as the research and development tax credits are not dependent on the Company generating future taxable income, the Company’s ongoing tax status, or tax position. The research and development incentives receivable represent an amount due in connection with the above program. The Company recorded a reduction to research and development expense of $3.3 million and $6.6 million for the year ended December 31, 2020 and 2019, respectively. Patent costs All patent-related costs incurred in connection with preparing, filing and prosecuting patent applications are expensed as incurred due to the uncertainty about the recovery of the expenditure. Amounts incurred are classified as general and administrative expenses in the consolidated statements of operations and comprehensive loss. Warrants The Company accounts for freestanding warrants within stockholder’s equity or as liabilities based on the characteristics and provisions of each instrument. The Company evaluates outstanding warrants in accordance with Accounting Standards Codification (“ASC”) 480, Distinguishing Liabilities from Equity Derivatives and Hedging Share-based compensation The Company accounts for share-based compensation in accordance with ASC 718, ‘Compensation – Stock Compensation”(“ASC 718”). ASC 718 requires companies to estimate the fair value of equity-based payment awards on the date of grant. The value of the portion of the award that is ultimately expected to vest is recognized as an expense over the requisite service period in the Company’s consolidated statements of operations and comprehensive loss. The Company records the expense for option awards using a graded vesting method. The Company accounts for forfeitures as they occur. For share-based awards granted to non-employee non-employee The Company reviews stock award modifications when there is an exchange of original award for a new award. The Company calculates for the incremental fair value based on the difference between the fair value of the modified award and the fair value of the original award immediately before it was modified. The Company immediately recognizes the incremental value as compensation cost for vested awards and recognizes, on a prospective basis over the remaining requisite service period, the sum of the incremental compensation cost and any remaining unrecognized compensation cost for the original award on the modification date. The fair value of stock options (“options”) on the grant date is estimated using the Black-Scholes option-pricing model using the single-option approach. The Black-Scholes option pricing model requires the use of highly subjective and complex assumptions, including the option’s expected term and the price volatility of the underlying stock, to determine the fair value of the award. Historically given the absence of an active market for the ordinary shares of F-star F-star commensurate with the expected term assumption. F-star F-star The Company uses the remaining contractual term for the expected life of non-employee The Company classifies share-based compensation expense in its consolidated statements of operations and comprehensive loss in the same manner in which the award recipient’s payroll costs are classified or in which the award recipient’s service payments are classified. Comprehensive loss Comprehensive loss includes net loss as well as o

Going Concern

Going Concern	12 Months Ended
	Dec. 31, 2020
Going Concern [Abstract]
Going Concern	3. Going Concern The accompanying consolidated financial statements have been prepared on a going concern basis, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business. The accompanying financial statements do not reflect any adjustments relating to the recoverability and reclassifications of assets and liabilities that might be necessary if the Company is unable to continue as a going concern. The Company expects its costs and expenses to increase as it continues to develop its product candidates and progress its current clinical programs and cost associated with being a public company. Pursuant to the requirements of Accounting Standard Codification (ASC) 205-40, 205-40. The Company has incurred significant losses and has an accumulated deficit of $47.2 million as of December 31, 2020. F-star expects to incur substantial losses in the foreseeable future as it conducts and expands its research and development activities. As of March 30, 2021, the date of issuance of the consolidated financial statements, the Company’s current cash deposits will not be sufficient to fund its current operating plan and planned capital expenditures for at least the next 12 months. These conditions give rise to a substantial doubt over the Company’s ability to continue as a going concern. The Company intends to seek additional funding through public equity, private equity, debt financing, collaboration partnerships, or other sources. There are no assurances, however, that the Company will be successful in raising additional working capital, or if it is able to raise additional working capital, it may be unable to do so on commercially favorable terms. The Company’s failure to raise capital or enter into other such arrangements if and when needed would have a negative impact on its business, results of operations and financial condition and its ability to develop its product candidates.

Business Combination

Business Combination	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
Business Combination	4. Business Combination As described in Note 1 above, on November 20, 2020, F-star Ltd completed its business combination with Spring Bank. For accounting purposes, the purchase price was based on (i) the fair value of Spring Bank common stock as of the Transaction date of $ million which was determined based on the number of shares of common stock in connection with the Transaction, (ii) the portion of the fair value attributable to in the money fully and partially vested stock options and warrants. Under the acquisition method of accounting, the total purchase price is allocated to the acquired tangible and intangible assets and assumed liabilities based on their fair values as of the acquisition date. Any excess purchase price over the fair value of assets acquired and liabilities assumed is allocated to goodwill. Acquired in-process research and development assets will be classified as indefinite-lived intangible assets and will be amortized over their estimated useful economic lives when put into use. The fair values of acquired in-process research and development assets were calculated using an income approach based on the expected future cash flows associated with the respective asset using an estimated discount rate of 14%. Goodwill is allocated to one reporting unit. The goodwill was primarily attributable to the access F-star Ltd gained to the Nasdaq public listing. The Company determined that the underlying goodwill and intangible assets are not deductible for tax purposes. For the year ended December 31, 2020, the Company incurred acquisition-related expenses of approximately $4.2 million which are included in general and administrative expenses. The purchase price is allocated to the fair value of assets and liabilities acquired as follows (in thousands, except common shares and fair value per share): Number of full common shares 4,449,559 Multiplied by fair value per share of common stock $ 4.84 Purchase price $ 21,536 Cash and cash equivalents $ 9,779 Marketable securities 5,000 Prepaid expenses and other assets 935 Operating lease right of use asset 2,784 Intangible assets 4,720 Goodwill 10,451 Accounts payable, accrued expenses and other liabilities (5,453 ) Contingent value rights (2,520 ) Liability and equity based warrants (422 ) Deferred tax liability (576 ) Operating lease liability (3,162 ) Fair value of net assets acquired $ 21,536 A liability was recognized for the contingent value rights assumed by the Transaction. The fair value estimate for the contingent value rights was estimated at $2.5 million and is based on the probability weighted achieved over the estimated period. Any change in the fair value of the contingent value rights to the acquisition date, including changes from events after the acquisition date, such as changes in our estimate will be recognized in earnings in the period the estimated fair value changes. The company’s estimated range of possible outcomes were up to $26.0 million. A change in fair value of the contingent value rights could have a material effect on the statement of operations and financial position in the period of the change in estimate. The results of this acquisition were included in the Company’s consolidated statement of operations and comprehensive loss beginning on November 20, 2020. The Company’s consolidated net loss for the year ended December 31, 2020, includes a loss of $1.7 million for Spring Bank operations since the Transaction date. The unaudited pro forma financial information presents the combined results of operations as if the Transaction had occurred on January 1, 2019. The unaudited pro forma financial information is not necessarily indicative of what the consolidated results of operations would have been had the Transaction occurred at the beginning of each year. In addition, the unaudited pro forma financial information does not attempt to project the future results of operations of the combined company. On a pro forma basis, the combined companies would have been a net loss of $ million for the year ended December 31, 2020 and 2019, respectively. The unaudited pro forma net losses for December 31, 2020 and 2019, respectively, gives effect to the exclusion of interest expense relating to the convertible debt and the change of the fair value relating the convertible debt.

2019 Corporate Reorganization

2019 Corporate Reorganization	12 Months Ended
	Dec. 31, 2020
Restructuring and Related Activities [Abstract]
2019 Corporate Reorganization	5. 2019 Corporate Reorganization On May 7, 2019, F-star F-star F-star F-star “F-star F-star Exchange of Delta Shares for F-star (the ‘Delta Share Exchange’) All shareholders of Delta exchanged each of the shares held by them in Delta for the same class and number of newly issued shares of F-star F-star F-star F-star of F-star F-star F-star F-star F-star F-star Exchange of GmbH, Beta and Alpha Shares for F-star Effective as of the date of and subsequent to the Delta Share Exchange, all shareholders of each of Alpha, Beta and GmbH exchanged each of the shares held in Alpha, Beta and GmbH for newly issued shares in F-star F-star F-star GmbH and Beta were deemed to meet the definition of a business in accordance ASC 805 and therefore the acquisitions were accounted for as business combinations, while the acquisition of a controlling interest in Alpha was accounted for as an asset acquisition. No other assets, including cash, were transferred or liabilities assumed as consideration for the corporate reorganization. The acquisition of F-star Beta As consideration paid for the acquisition of Beta, F-star The assets and liabilities recognized as a result of the acquisition of Beta are as follows (in thousands): Cash and cash equivalents $ 1,205 Other current assets 5,475 In-process 15,958 Goodwill 2,293 Current liabilities (19,376 ) $ 5,555 The acquisition of Beta by Delta did not contribute any revenue and contributed a loss of $12.4 million during 2019 for the period of May 7, 2019 through December 31, 2019. The following unaudited supplemental pro forma information summarizes the results of operations of Beta as if the acquisition had occurred on January 1, 2018: Period from 2019 Revenue $ — Net loss (5,549 ) The goodwill is attributable to the contracted access to an organized workforce and will not be deductible for tax purposes. The in-process research and development intangible assets represent the acquisition-date fair value of three development programs acquired from Beta, which the Company refers to as the FS120, FS222 and FS21. FS120 and FS222 are Beta proprietary assets and FS21 is partnered. The fair value of the IPR&D intangible assets was based on assumptions that market participants would use in pricing the assets, given that they are early stage, based on the most advantageous market for the assets assuming highest and best use. The fair value of assets not subject to partnering agreements (FS120 and FS222) was determined using a cost approach, which utilized net amount invested with a return on investment commensurate with the achievement of certain value inflection events, benchmarked against publicly available information from comparable companies. For the partnered asset (FS21) the calculations include cash flow projections based on financial budgets approved by management covering a three-year year These IPR&D intangible assets are not amortized, but rather are reviewed for impairment on an annual basis or more frequently if indicators of impairment are present, until the project is completed, abandoned or transferred to a third party. The intangible assets acquired with Beta are summarized in the table below (in thousands): FV Description FS21 $ 4,426 Contracted future cash flows relating to a drug candidate that has been licensed to a collaboration partner FS120 6,359 Internally developed drug candidate, for which Beta holds the IP rights FS222 5,173 Internally developed drug candidate, for which Beta holds the IP rights $ 15,958 GmbH Group As consideration paid for the acquisition of GmbH, F-star Ltd issued of series A preferred shares, seed preferred shares and of ordinary shares at a fair value of $ million on the date of acquisition. The assets and liabilities recognized as a result of the acquisition of GmbH Group are as follows (in thousands): Cash $ 952 Other current assets 18,211 Property and equipment 1,965 Right of use assets 975 In process research and development 1,436 Equity investment 56 Current liabilities (15,751 ) Other non-current (466 ) Goodwill 2,044 $ 9,422 The acquisition of GmbH Group contributed revenue of $2.4 million and a loss of $14.6 million to the Company’s results from May 7, 2019 through December 31, 2019. The goodwill is attributable to the workforce and will not be deductible for tax purposes. The following unaudited supplemental pro forma information summarizes the results of operations of GmbH as if the acquisition had occurred on January 1, 2018: Period from 2019 Revenue $ 1,811 Net (loss) income $ (6,880 ) The goodwill is attributable to the workforce and will not be deductible for tax purposes. Alpha F-star non-current

Prepaid expenses and other curr

Prepaid expenses and other current assets	12 Months Ended
	Dec. 31, 2020
Prepaid Expense and Other Assets, Current [Abstract]
Other Current Assets [Text Block]	6. Prepaid expenses and other current assets Prepaid expenses and other current assets on December 31, 2020, and 2019 consist of the following (in thousands): 2020 2019 Research and Development $ 526 $ 1,382 Rent 705 220 Clinical Trial Costs 846 204 License Fees — 608 VAT recoverable 443 842 Insurance 277 — Refunds due 420 — Other 759 332 $ 3,976 $ 3,588

Property, plant and equipment,

Property, plant and equipment, net	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Property, plant and equipment, net	7. Property, plant and equipment, net Property, plant and equipment, net consisted of the following (in thousands): 2020 2019 Leasehold improvements $ 15 $ 14 Laboratory equipment 1,788 1,725 Furniture and office equipment 169 194 1,972 1,933 Less: Accumulated depreciation 1,183 508 $ 789 $ 1,425 Depreciation expense was $1.1 million and $0.8 million for the year ended December 31, 2020 and 2019, respectively. During the year ended December 31, 2019, the Company disposed of property, plant and equipment with a gross book value and accumulated depreciation of less than $0.1 million. There was no material gain or loss resulting from the disposals.

Goodwill and In-process Researc

Goodwill and In-process Research and Development	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets Disclosure [Text Block]	8. Goodwill and In-process Research and Development The changes in the carrying amount of Goodwill and In-process Goodwill In-process Amount acquired as of May 7, 2019 $ 4,337 17,395 Capitalized — 127 Impairments during the year — (4,152 ) Effect of changes in exchange rate used for translation (17 ) (321 ) Balance at December 31, 2019 $ 4,320 $ 13,049 Capitalized — 730 Acquired by the Transaction 10,451 4,720 Effect of changes in exchange rate used for translation 155 487 Balance at December 31, 2020 $ 14,926 $ 18,986 The Company’s In-process

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	9. Fair Value Measurements The following tables present information about the Company’s financial assets and liabilities measured at fair value on a recurring basis and indicate the level of the fair value hierarchy utilized to determine such fair values (in thousands): Fair Value Measurements as of Level 1 Level 2 Level 3 Total Liabilities: Contingent value rights $ — $ — $ 2,520 $ 2,520 Warrants — — 37 37 $ — $ — $ 2,557 $ 2,557 The Company classified the contingent value rights within Level 3 because their fair values are determined using net present value techniques, based upon non-public Fair Value Measurements as of Level 1 Level 2 Level 3 Total Liabilities: Convertible notes $ — $ — $ 14,906 $ 14,906 The convertible notes were recorded at fair value upon the date of issuance and was subsequently remeasured to fair value at each reporting date. Immediately prior to the completion of the share exchange on November 20, 2020, the convertible notes were converted to 1,445,779 common shares. The principal amount and accrued interest at the date of conversion were $19.2 million and $1.0 million, respectively. The Company recognized a $2.4 million gain for the change in fair value of the convertible notes immediately prior to the conversion in the statement of operations and comprehensive loss, and the principal amount was recorded to equity. The following table reflects the change in the Company’s Level 3 liabilities, which consists of the liability based warrants outstanding as of November 20, 2020 through December 31, 2020 (in thousands): November Private Fair value of liability based warrants outstanding as of November 20, 2020 $ 221 Warrants exercised (184 ) Balance at December 31, 2020 $ 37

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	12 Months Ended
	Dec. 31, 2020
Payables and Accruals [Abstract]
Accrued Expenses and Other Current Liabilities	10. Accrued Expenses and Other Current Liabilities Accrued expenses at December 31, 2020 and 2019 2020 2019 Clinical Trial Costs $ 3,394 $ 5,892 Severance 1,953 — Compensation and Benefits 1,361 1,190 Professional Fees 1,593 1,305 Payroll taxes — 257 Other 1,160 232 $ 9,461 $ 8,876

Convertible Notes

Convertible Notes	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Convertible Term Loan	11. Convertible Notes F-star September 19, 2019 The notes were convertible into a variable number of series A preference shares at the option of the holder together with interest outstanding, in the event F-star Ltd raised at least USD $ million or there was a change of control. On expiry of the term, if no conversion notice has been issued, the notes would be redeemable at principal plus accrued interest. The initial fair value of the convertible notes designated at fair value through profit and loss (“FVTPL”) was determined as the transaction price, as this is deemed to be at arm’s length in accordance with the guidance set out in ASC 825. Subsequent measurement of fair value was determined using a weighted average percentage probability of various possible scenarios for conversion of the notes. The key assumption in calculating the fair value of the embedded derivative as through the date conversion, was the probability of securing Series B financing of 90% with the balance of probability allocated to no funding and redemption on expiry (in which case the value of the derivative is zero). Immediately prior to the completion of the share exchange on November 20, 2020, the convertible notes were converted to 1,445,779 common shares. The principal amount and accrued interest at the date of conversion were $19.2 million and $1.0 million, respectively. The Company recognized a $2.4 million gain for the change in fair value of the convertible notes immediately prior to the conversion in the statement of operations and comprehensive loss, and the principal amount was recorded to equity. The following table provides a roll-forward of the fair values of the Company’s convertible note for which fair value was determined by Level 3 inputs (in thousands): Convertible notes at fair value Balance on December 31, 2019 $ 14,906 Proceeds from issuance 850 Interest 978 Effects of foreign exchange 29 Fair value gain 2,386 Conversion of notes to equity (19,149 ) Fair value at December 31, 2020 $ —

Warrants

Warrants	12 Months Ended
	Dec. 31, 2020
Warrants and Rights Note Disclosure [Abstract]
Warrants	12. Warrants In connection with Spring Bank’s IPO in 2016, there was an issuance of warrants to the sole book-running manager to purchase 7,087 per share and expire on . The Company evaluated the terms of the warrant s and concluded that they should be equity-classified. At December 31, 2020, there were warrants outstanding. During 2016, Spring Bank entered into a definitive agreement with respect to the private placement of 411,184 shares of common stock and warrants to purchase 411,184 shares of common stock (the “November 2016 Private Placement Warrants”) to a group of accredited investors. The November 2016 Private Placement Warrants are exercisable at an exercise price of $43.16 per share and expire on November 23, 2021. The Company evaluated the terms of these warrants and concluded that they are liability-classified. The Company must recognize any change in the value of the warrant liability each reporting period in the statement of operations and comprehensive loss. As of December 31, 2020, the fair value of the November 2016 Private Placement Warrants was approximately $37,000 and 340,137 warrants have been exercised to date. At December 31, 2020, there were 71,047 warrants outstanding A summary of the Black-Scholes pricing model assumptions used to record the fair value of the warrants is as follows: 2020 Risk-free interest rate 1.9 % Expected term (in years) 0.9 Expected volatility 100.0 % Expected dividend yield 0 % During 2019, Spring Bank entered into an agreement with Pontifax Medison Finance (Israel) L.P. and Pontifax Medison Finance (Cayman) L.P., as lenders, and Pontifax Medison Finance GP, L.P warrants to purchase 62,500 shares of common stock (the “Pontifax Warrants”). The Pontifax Warrants are exercisable at $8.32 per share and expire on September 19, 2025. The Company evaluated the terms of the warrant s they During 2019, Spring Bank issued warrants to a service provider to purchase 3,750 shares of common stock (the “September 2019 Warrants”). The September 2019 Warrants are exercisable at an exercise price of $16.84 per share and expire on September 19, 2021. The Company evaluated the terms of the warrant s they . A summary of the warrant activity for the Company since the Closing Date of the Transaction to the year ended December 31, 2020 is as follows: Warrants Warrant outstanding as of November 20, 2020 481,781 Exercises (337,397 ) Outstanding at December 31, 2020 144,384

Stock Option Plans

Stock Option Plans	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Stock Option Plans	13. Stock Option Plans Incentive Plans On June 14, 2019, as part of the group restructuring, the F-star F-star (F-star F-star F-star F-star F-star Awards granted under the 2019 Plan generally vest over a four-year In conjunction with the Transaction, all issued and outstanding F-star F-star F-star F-star Limited 2019 Equity Incentive Plan (F-star 2019 plan) were replaced by options (“Replacement Options”) and awards (“Replacement RSUs”), on the same terms (including vesting), for Company common stock, based on the Exchange Ratio. The Company determined that the exchange of F-star Ltd awards for the Company awards would be accounted for as a modification of awards under ASC 718. The Company concluded that the modification will not affect the number of awards expected to vest or the service period over which compensation expense related to awards will be recognized since the vesting schedule applicable to each Replacement Option will be the same as the vesting schedule applicable to the original option that it replaces. In addition, the Replacement RSUs and Replacement Options will be subject to the same terms and conditions as the original RSUs and original options, respectively (except to the extent such terms are rendered inoperative because of the transactions contemplated by the Exchange Agreement) and will not provide holders of the Replacement Options or Replacement RSUs with any additional benefits that the holders did not have under their original options or original RSUs. In addition, the fair value of an award tranche immediately after modification was less than the fair value of that award tranche immediately before modification therefore total compensation cost that is recognized for the Replacement RSUs and Replacement Options equal the grant-date fair value of the original award and the Company will continue to recognize the grant date fair values of the modified awards over their respective service periods. Amended and Restated 2015 Stock Incentive Plan In March 2018, the Board approved the Amended and Restated 2015 Plan. Upon receipt of stockholder approval at the Company’s 2018 annual meeting in June 2018, the 2015 Plan was amended and restated in its entirety increasing the authorized number of shares of common stock reserved for issuance by 800,000 shares (together with the 2014 Plan, the 2015 Plan, the “Stock Incentive Plans”). Pursuant to the Amended and Restated 2015 Plan, there are 1,666,863 shares authorized for issuance. In addition, to the extent any outstanding awards under the 2014 Plan expire, terminate or are otherwise surrendered, cancelled or forfeited after the closing of the Company’s IPO, those shares are added to the authorized shares under the Amended and Restated 2015 Plan. The total amount of shares authorized for issuance under both the 2014 Plan and the Amended and Restated 2015 Plan is 2,300,000. Pursuant to the Exchange Agreement, all outstanding options to purchase Company common stock were accelerated immediately prior to the Closing and each outstanding option with an exercise price less than the trading price of the Company common stock as of the close of trading on the Closing Date was exercised in full and all other outstanding options to purchase Company common stock were cancelled effective as of the Closing Date. As of December 31, 2020, the Company had 678,949 shares available for issuance under the Amended and Restated 2015 Plan. Stock option valuation The fair value of stock option grants is estimated using the Black-Scholes option-pricing model with the following assumptions:. 2020 2019 Risk-free interest rate 0.17% - % 1.74% - % Expected volatility 82.8% - % 70.03 - 70.31 % Expected dividend yield 0 % 0 % Expected life (in years) 5.1 5.1 Expected Term Volatility F-star considered to be comparable to F-star Ltd business over a period equivalent to the expected term of the share-based awards. After the closing of the Transaction, the volatility of the Company’s Common Stock is used to determine volatility of the share-based awards at grant date. Risk-Free Interest Rate zero-coupon Dividend Rate Fair Value of Common Stock F-star Number of Weighted Weighted Average Aggregate Intrinsic (in years) (in thousands) Balance on December 31, 2019 259,148 $ 7.07 9.24 $ 4,334 Granted 415,343 0.20 — — Exercised (42,260 ) 0.10 — — Forfeited (28,883 ) 4.79 — — Outstanding as of December 31, 2020 603,348 $ 2.94 9.30 $ 8,494 Options exercisable at December 31, 2020 89,957 $ 9.24 8.70 $ 1,228 The weighted average grant date fair value of options granted during the year ended December 31, 2020 and 2019, was $14.45 and $23.94 per share, respectively. The total fair value of options vested during the years ended December 31, 2020, and 2019, was $2.0 million and $1.6 million, respectively. Share-based compensation The Company recorded share-based compensation expense in the following expense categories for the year ended December 31, 2020 and 2019 of its consolidated statements of operations and comprehensive loss (in thousands): 2020 2019 Research and development expenses $ 684 $ 554 General and administrative expenses 2,805 2,115 $ 3,489 $ 2,669 As of December 31, 2020, and 2019, the total unrecognized compensation cost relating to unvested options granted was $5.1 million and $2.7 million, respectively, which is expected to be realized over a period of 3.2 years and 2.9 years, respectively. The Company will issue shares upon exercise of options from shares reserved under the Plan.

Significant agreements

Significant agreements	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Significant agreements	14. Significant agreements License and Collaboration agreements For the years ended December 31, 2020 and 2019, the Company had License and Collaboration agreements (“LCA”s) with Denali Therapeutics Inc. (“Denali”) and Ares Trading S.A (“Ares”). The following table summarizes the revenue recognized in the Company’s consolidated statements of operations and comprehensive loss from these arrangements, (in thousands): Year Ended 2020 2019 Collaboration revenues Ares (Switzerland) $ 9,930 $ 25,871 Denali (US) 1,326 2,450 Total collaboration revenues $ 11,256 $ 28,321 License and collaboration agreement with Denali Therapeutics Inc. Summary In August 2016, F-star F-star (“F-star f-star Forschungs-und non-native F-star buy-out-option, F-star pre-negotiated On May 30, 2018, Denali exercised such buy-out F-star F-star As a result of the Acquisition, F-star F-star F-star F-star F-star F-star F-star million upon the achievement of certain defined preclinical, clinical, regulatory and commercial milestones. Of this total, a maximum of pre-defined Under the terms of the Denali License and Collaboration Agreement, Denali has the right to nominate up to three Fcab targets for approval (“Accepted Fcab Targets”), within the first three years of the date of the Denali License and Collaboration Agreement. Upon entering into the Denali License and Collaboration Agreement, Denali had selected transferrin receptor, or TfR, as the first Accepted Fcab Target and paid an upfront fee of $5.5 million to F-star one-time Denali is also responsible for certain research costs incurred by the Company in conducting activities under each agreed development plan, for up to 24 months. Under the terms of the Denali License and Collaboration Agreement, the Company is prohibited from developing, commercializing and manufacturing any antibody or other molecule that incorporates any Fcab directed to an Accepted Fcab Target, or any such Fcab as a standalone product, and from authorizing any third party to take any such action. Revenue recognition The Company has considered the performance obligations identified in the contracts and concluded that the grant of intellectual property rights is not distinct from the provision of R&D services, as the R&D services are expected to significantly modify the early-stage intellectual property. As a result, the grant of intellectual property rights and the provision of R&D services has been combined into a single performance obligation for this contract. The initial transaction price for first Accepted Fcab Target was deemed to be $7.1 million consisting of $5.0 million for the grant of intellectual property rights and $2.1 million for R&D services, and $5.1 million for the second Accepted Fcab Target consisting of $3.0 million for the grant of intellectual property rights and $2.1 million for R&D services. During the year ended December 31, 2019, the transaction price for the first accepted Fcab was increased to $6.6 million due to achievement of a $1.5 million milestone that on initial recognition of the contract was not included in the transaction price, as it was not deemed probable that a reversal would not occur in a future reporting period. The Company recognized the $1.5 million at a point in time. No other revenue was recognized for the first accepted Fcab in the year as the performance obligation identified in the contract was deemed to have been fully satisfied prior to May 7, 2019, the date of acquisition of F-star During the years ended December 31, 2020 and 2019 the Company recognized $1.3 million and $0.9 million respectively over time in respect of the second Fcab target. 2019 License and collaboration agreement with Ares Trading S.A. In June 2017, Delta entered into a License and Collaboration Agreement (“LCA”) and an Option Agreement with Ares Trading S.A (“Ares”). The purpose of the LCA was for the companies to collaborate on the development of tetravalent bispecific antibodies against five drug target pairs. The Option Agreement granted Ares a call option to acquire the entire issued share capital of Delta. Under the LCA the company was obligated to use commercially reasonable efforts to perform R&D activities on the five selected target pairs, under mutually agreed research plans. The activities were governed by a joint steering committee formed by an equal number of representatives from both parties. On May 14, 2019, the LCA agreement with Ares was amended and restated to convert the existing purchase option over the entire share capital of Delta to an intellectual property licensing arrangement that includes the exclusive grant of development and exploitation rights to one tetravalent bispecific antibody directed against immuno-oncology targets and the option to acquire the exclusive right to an additional antibody. As part of the amended LCA, Delta now has exclusive rights to FS118, its lead product candidate, which is currently in a proof-of-concept For the exclusive rights granted in relation to the first molecule, an option fee of $11.1 million was paid by Ares to Delta. Following receipt of the option fee, Ares becomes responsible for the development of the molecule and development, regulatory and sales-based royalties become payable to Company upon achievement of specified events. The Company is eligible to receive $71.6 million in development milestones and $83.9 million in regulatory milestones. For the second antibody included within the amended and restated agreement, Delta is obliged to perform research activities under plans agreed by both parties. Ares will pay for all R&D costs half-yearly in advance until the company delivers the data package specified in the research plan. Ares can then elect to pay a fee of $14.0 million to exercise their option to take an exclusive intellectual property license, which allows them to control the development and exploitation of the molecule. Following receipt of the option fee, Ares is responsible for the development of the molecule and development, regulatory and sales-based royalties become payable to Delta upon achievement of specified events. Delta is eligible to receive $48.7 million in development milestones and $61.6 million in regulatory milestones. Development milestone payments are triggered upon achievement by each product candidate of a defined stage of clinical development and regulatory milestone payments are triggered upon approval to market a product candidate by the FDA or other global regulatory authorities. Sales-based milestones are payable based upon aggregate annual worldwide net sales in all indications of all licensed products. The company is eligible to receive $168.0 million in sales-based milestones. In addition, to the extent that any product candidates covered by the exclusive licenses granted to Ares are commercialized, the company will be entitled to receive a single digit royalty based on a percentage of net sales on a country-by-country On July 15, 2020 (“2020 Amendment”), a deed of amendment was enacted in respect of the May 14, 2019 . Revenue recognition Management has considered the performance obligations identified in the contracts and concluded that the option for the grant of intellectual property rights is not distinct from the provision of R&D services in the agreements, as the R&D services are expected to significantly modify the early-stage intellectual property. As a result, the option for the grant of intellectual property rights and the provision of R&D services has been combined into a single performance obligation for all molecules under the original contract and each individual molecule included in the May 14, 2019, amendment. The Company recognizes revenue using the cost-to-cost method, which it believes best depicts the transfer of control of the services to the customer. Under the cost-to-cost method, the extent of progress towards completion is measured based on the ratio of actual costs incurred to the total estimated costs expected upon satisfying the identified performance obligation. In the year ended December 31, 2019, $13.3 million Licensing and R&D services revenue relating to the five antibodies included in the original LCA was recognized, based on the cost-to-cost All performance obligations in the original contract were deemed to have been fully satisfied on termination of the agreement on May 14, 2019, and no further revenue is expected to be recognized. The total transaction price for the amended and restated LCA was initially determined to be $15.4 million, consisting of the upfront payment and R&D funding for the research term. Variable consideration to be paid to the company upon reaching certain milestones had been excluded from the calculation, as at the inception of the contract, it was not probable that a significant reversal of revenue recognized would not occur in a subsequent reporting period. In the year ended December 31, 2019, $11.1 million Licensing and R&D services revenue for the first antibody included within the amended and restated LCA was recognized at a point in time, as no further performance obligations were identified. cost-to-cost There were two components identified in the 2020 amendment, each of which was accounted for as a separate performance obligation. The grant of the additional options to acquire intellectual property rights was deemed to be distinct, as the customer can benefit from it on its own, and it is independent of the delivery of other performance obligations in the original contract. Additionally, as the amount of consideration reflects a standalone selling price, the Company determined that the second component is accounted for as a separate contract. The second component that allows the customer to exercise its option to acquire intellectual property rights early is considered to be a modification of the original contract, as the option is not independent of the R&D services provided under the original contract, and therefore the goods and services are not distinct. The Company updated the transaction price and measure of progress for the performance obligation relating to this molecule. All performance obligations under the May 13, 2019 agreement in respect of the second molecule were deemed to have been fully satisfied on July 15, 2020 and the option fee of As a result of this amendment, the maximum amount payable by Ares Trading S.A on the achievement of certain development and regulatory milestones in the aggregate is increased to $501.7 million, and the maximum amount payable on the achievement of certain commercial milestones is increased to $309.5 million. On March 26, 2021, Ares provided notice of its intention to exercise its option granted under the 2020 Amendment to acquire the intellectual property rights for an additional molecule. An option fee of $3.1 million is payable upon option exercise. Summary of Contract Assets and Liabilities Up-front The following table presents changes in the balances of the Company’s contract assets and liabilities (in thousands): Year ended December 31, 2020 Balance at Additions Recognized Impact of Balance at Contract liabilities: Ares collaboration $ 33 $ 37 $ (33 ) $ — $ 37 Denali collaboration 409 — (151 ) 5 263 Total deferred revenue $ 442 $ 37 $ (184 ) $ 5 $ 300 Year ended December 31, 2019 Balance at Acquired with Additions Recognized Impact of Balance at Contract liabilities: Ares collaboration $ 5,824 $ — $ — $ (5,903 ) $ 112 $ 33 Denali collaboration — 869 31 (473 ) (18 ) 409 Total deferred revenue $ 5,824 $ 869 $ 31 $ (6,376 ) $ 94 $ 442 During the years ended December 31, 2020, and 2019, all revenue recognized by the Company as a result of changes in the contract liability balances in the respective periods was based on proportional performance.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	15. Income Taxes For the years ended December 31, 2020, and 2019, the Company recognized an immaterial total income tax benefit and a total income tax benefit of $ million, respectively. The Company is subject to corporate taxation in the United Kingdom, United States and Austria. The Company’s income tax benefit provision in the year ended December 31, i s mainly the result of US federal branch taxes and a prior year adjustment in Austria. The income tax benefit in the year ended December 31, 2019 is mainly the result of the reduction in deferred tax liabilities arising on acquired IPR&D assets due to the intangible asset impairment. Year Ended 2020 2019 United Kingdom $ (24,490 ) $ (20,943 ) Austria 315 (62 ) United States (1,445 ) (2,745 ) Total $ (25,620 ) $ (23,750 ) The components of the benefit for income taxes are as follows (in thousands): Year Ended 2020 2019 Federal $ (41 ) $ (152 ) State — (7 ) Foreign 42 — Total current income tax (provision) benefit 1 (159 ) Total deferred income tax (benefit) — 896 Total benefit from income taxes $ 1 $ 737 The Company is subject to the corporate tax rate in the United States. In the year ended December 31, 2019 the Company was subject to the rate of corporate tax in the United Kingdom (19%) due to the ultimate parent entity (FTL) being UK-domiciled. Year Ended 20 20 201 9 Income tax (provision) benefit at statutory rate 21.0 % 19.0 % Expenses not deductible (9.4 %) (8.5 %) Net losses surrendered for U.K. R&D tax credit (4.6 %) (10.3 %) Change in valuation allowance (7.1 %) 3.8 % Foreign rate differential (1.5 %) (0.1 %) Adjustment in respect to 1.6 % (0.8 %) Actual income tax expense effective tax rate 0.0 % 3.1 % non-deductible Significant components of the Company’s current and deferred tax assets (liabilities) as at December 31, 2020 and 2019, were as follows (in thousands): Year Ended 2020 2019 Deferred tax assets: Net operating loss carryforwards $ 45,053 $ Research and development credit carryforwards 957 — Capitalized R&D expenditures 5,238 — Lease Obligation 860 — Stock option expense 1,206 742 Other 18 — Total gross deferred $ 53,332 $ 10,145 Valuation Allowance (49,304 ) (7,607 ) Net deferred tax assets 4,028 2,538 Deferred tax liabilities: Acquired Intangibles (3,763 ) (2,205 ) Right of Use Assets (769 ) — Capital Allowances (72 ) (333 ) Net deferred tax liability $ (576 ) $ — The Company regularly assesses its ability to realize its deferred tax assets. Assessing the realization of deferred tax assets requires significant judgment. In determining whether its deferred tax assets are more likely than not realizable, the Company evaluated all available positive and negative evidence, and weighed the evidence based on its objectivity. After consideration of the evidence, including forecasts and strategic plans, management has concluded that it is more likely than not that the Company will not realize the benefits of its deferred tax assets and accordingly the Company has provided a valuation allowance for the full amount of the net deferred tax assets. The Company intends to continue to maintain a full valuation allowance on its deferred tax assets until there is sufficient evidence to support the reversal of all or some portion of these allowances. The release of the valuation allowance would result in the recognition of certain deferred tax assets and an increase to the benefit for income taxes for the period the release is recorded. However, the exact timing and amount of the valuation allowance release are subject to change on the basis of the level of profitability that the Company is able to actually achieve. Management has determined that it is more likely than not that the Company will not recognize the benefits of its federal, state, and foreign deferred tax assets, and as a result, a valuation allowance of $49.3 million and $7.6 million has been established at December 31, 2020, and 2019, respectively. $41.7 net operating loss share exchange $125.8 million, $126.5 million, and $48.9 million, respectively, which expire beginning in 2030. The Company’s unsurrendered U.K. and Austrian net operating losses, and its U.S. federal net operating losses generated after December 31, 2017, do not expire. The Internal Revenue Code of 1986, as amended (the Code), provides for a limitation of the annual use of net operating losses and other tax attributes (such as research and development tax credit carryforwards) following certain ownership changes (as defined by the Code) that could limit the Company’s ability to utilize these carryforwards. At this time, the Company has not completed a study to assess whether an ownership change under Section 382 of the Code has occurred, or whether there have been multiple ownership changes since the Company’s formation. The Company may have experienced ownership changes, as defined by the Code, as a result of past transactions. Accordingly, the Company’s ability to utilize the aforementioned carryforwards may be limited. In addition, U.S. tax laws limit the time during which these carryforwards may be applied against future taxable income and tax, respectively. Therefore, the Company may not be able to take full advantage of these carryforwards for federal or state income tax purposes. U.K. and Austrian losses may be utilized to offset future taxable profits, subject to numerous utilization criteria and restrictions. The amount that can be offset each year is limited to As of December 31, 2020, the Company had federal and state research and development tax credit carryforwards of $0.3 million and $0.8 million, respectively, which expire beginning in 2031. The Company files income tax returns in the United Kingdom, in Austria and in the United States for federal income taxes and in the Commonwealth of Massachusetts for state income taxes. In the ordinary course of business, the Company is subject to examination by tax authorities in these jurisdictions. The 2019 tax year remains open to examination by HM Revenue & Customs. The statute of limitations for assessment with the Internal Revenue Service is generally three years from filing the tax return. As such, all years since inception in the U.S. remain open to examination. The statute of limitation for assessment with the Austrian tax authorities is a period of five years following the end of each fiscal year. Therefore, all fiscal years from 2016 to 2020 remain open for assessment. The Company is currently not under examination by any jurisdictions for any tax years. The Company recognizes, in its consolidated financial statements, the effect of a tax position when it is more likely than not, based on the technical merits, that the position will be sustained upon examination. The Company had no uncertain tax positions during the years ended of December 31, 2020, and 2019. There are no amounts of interest or penalties recognized in the consolidated statement of operations or accrued on the consolidated balance sheets for any period presented. The Company does not expect any material changes in these uncertain tax benefits within the next 12 months. The Company recognizes interest and penalties related to uncertain tax positions in income tax expense. As of December 31, 2020, and 2019, the Company had no accrued interest or penalties related to uncertain tax positions and no amounts have been recognized in the Company’s statements of operations and comprehensive loss.

Net Loss Per Share

Net Loss Per Share	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Net Loss Per Share	16 The following table summarizes the computation of basic and diluted net loss per share of the Company for such years 2020 2019 Net loss $ (25,619 ) $ (23,013 ) Weighted average number shares outstanding, basic and diluted 2,643,175 1,545,177 Net loss income per common, basic and diluted $ (9.69 ) $ (14.89 ) Diluted net loss per common share is the same as basic net loss per common share for all years For the year ended December 31, 2020, 501,255 potential stock options have been excluded from diluted earnings per share due the net loss and 102,093 stock options are anti-dilutive and have been excluded from the diluted earnings per share computation as the exercise prices of these common shares were above the market price of the common stock for the years

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	17. Commitments and Contingencies Lease Obligations On January 27, 2021, the Company signed an operating lease for three years for its c As of December 31, 2020, Operating lease costs under the leases for the year ended December 31, 2020 and 2019, were approximately $0.3 million and $0.4 million. Total operating lease costs for the year ended December 31, 2020, were offset by an immaterial amount for sublease income. The following table summarizes the Company’s maturities of operating lease liabilities as of December 31, 2020 (in thousands): Year 2021 $ 542 2022 451 2023 462 2024 474 2025 486 Thereafter 1,444 Total lease payments $ 3,859 Sublease The Company subleases two former Spring Bank offices in Hopkinton, Massachusetts. Operating sublease income under operating lease agreements for the year ended December 2020 was immaterial. These subleases 0.4 years 7.6 years Year 2021 $ 83 2022 462 2023 474 2024 486 2025 498 Thereafter 1,482 Total sublease receipts $ 3,485 Service Agreements As of December 31, 2020, and 2019, the Company has contractual commitments of $4.7 million and $1.0 million, respectively with a contract manufacturing organization (“CMO”) for activities that are ongoing or are scheduled to start between 3 and 9 months of the date of the statement of financial position. Under the terms of the agreement with the CMO, the Company is committed to pay for some activities if those activities are cancelled up to 3, 6 or 9 months prior to the commencement date. Contingencies – stockholder litigation due to the share exchange The following are contingent liabilities of the Company that were acquired on November 20, 2020: On September 3, 2020, a Spring Bank stockholder filed a complaint in the United States District Court for the Southern District of New York (Lenthall v. Spring Bank Pharmaceuticals, Inc. et al, Case No. 1:20-cv-07219 14a-9 S-4 S-4”), F-star On September 8, 2020, in the United States District Court for the District of Delaware, a purported class action (Adam Franchi v. Spring Bank Pharmaceuticals, Inc. et al, Case No. 1:20-cv-01198 F-star 14a-9 S-4 F-star On September 18, 2020, in the United States District Court for the Southern District of New York, another Spring Bank stockholder filed a complaint (Arshad v. Spring Bank Pharmaceuticals, Inc., et al., Case No. 1:20-cv-07723 14a-9 S-4 F-star On October 29, 2020, in the United States District Court Eastern District of New York, another Spring Bank stockholder filed a complaint (Nowakowski v. Spring Bank Pharmaceuticals, Inc., et al., Case No. 1:20-cv-05219 14a-9 S-4 F-star 14a-9

Employee Plans

Employee Plans	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement, Disclosure [Abstract]
Employee Plans	18. Employee Plans The Company provides a defined contribution plan for its employees in the United Kingdom and United States, pursuant to which the Company may match employees’ contributions each year. During each of the years

Related Party Transactions 2019

Related Party Transactions 2019 Reorganization	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Related Party Transactions 2019 Reorganization	19. Related Party Transactions 2019 reorganization The transactions that resulted in the 2019 reorganization, in the year ended December 31, 2019, are deemed to be related party transactions by virtue of common directorships between the entities. There were no related party transactions for 2020. Key management personnel (including directors) During the year ended December 31, 2020 and 2019, the Company had purchases totaling none and $0.2 million, respectively, from Avacta Life Sciences Limited, a company in which the Company’s Chief Executive Officer also holds a directorship. As of December 31, 2020, and 2019, the amounts outstanding and included in trade and other payables was none and $0.1 million, respectively. On February 28, 2019, the F-star sub-lease US-based A non-executive Related party transactions prior to 2019 reorganization A summary of related party transactions for the year ended December 31, 2019, where exemption from reporting transactions and balances between group undertakings is unavailable under ASC 850 ‘Related Party Disclosures’, are disclosed below. For the year ended December 31, 2019, only transactions prior to the group reorganization on May 7, 2019, are disclosed. Some of the directors of Delta were also directors of Beta as well as members of the supervisory board of GmbH, which has a wholly owned subsidiary, F-star Delta, Beta and F-Star sub-licensed F-star F-star F-star 2019 R&D Other Expenses Beta $ 2,126 $ 552 F-star 235 — GmbH — 13 R&D recharges relate to research paid for by Delta and carried out by F-star These research services are based on time incurred and are charged on an FTE basis. In addition, certain non-employment F-star

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2020
Subsequent Events [Abstract]
Subsequent Events	20. Subsequent events On March 26, 2021, Ares provided notice of its intention to exercise its option granted under the 2020 Amendment to acquire the intellectual property rights for an additional molecule. An option fee of $3.1 million is payable upon option exercise.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The Company’s financial statements have been prepared in conformity with generally accepted accounting principles in the United States of America (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”). The accompanying consolidated financial statements include the accounts of F-star F-star (F-star F-star F-star F-star F-star f-star Forschungs-und F-star All intercompany balances and transactions between the consolidated companies have been eliminated in consolidation.
Use of Estimates	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 consolidated financial statements and the reported amounts of expenses during the F-star
Foreign currency and currency translation	Foreign currency and currency translation The functional currency is the currency of the primary economic environment in which an entity’s operations are conducted. The Company and its subsidiaries operate mainly in the United Kingdom, United States and Austria. The Company’s reporting currency is the U.S dollar. The Company translates the assets and liabilities of its subsidiaries into U.S. dollar at the exchange rate in effect on the balance sheet date. Revenues and expenses are translated at the average exchange rate in effect during each monthly period. Unrealized translation gains and losses are recorded as a cumulative translation adjustment, which is included in the consolidated statements of shareholders’ equity as a component of accumulated other comprehensive (loss)income. Translation differences resulting from the conversion from functional currency to reporting currency are included as part of the cumulative foreign currency translation adjustment, which is reported as a component of shareholders’ equity under accumulated other comprehensive loss. Monetary assets and liabilities denominated in currencies other than the functional currency are remeasured into the functional currency at rates of exchange prevailing at the balance sheet dates. Non-monetary Adjustments that arise from exchange rate changes on transactions denominated in a currency other than the local currency are included in other (expense) income in the consolidated statements of operations and comprehensive loss as incurred. The Company recorded a foreign exchange loss of $0.4 million and a gain of $0.3 million included in other (expense) income in the consolidated statement of operations and comprehensive loss for the years ended December 31, 2020, and 2019, respectively.
Emerging Growth Company	Emerging Growth Company Section 102(b)(1) of the Jumpstart Our Business Startups Act of 2012 (the “JOBS Act”) exempts emerging growth companies from being required to comply with new or revised financial accounting standards until private companies (that is, those that have not had a Securities Act registration statement declared effective or do not have a class of securities registered under the Exchange Act) are required to comply with the new or revised financial accounting standards. The JOBS Act provides that an emerging growth company can elect to opt out of the extended transition period and comply with the requirements that apply to non-emerging
Concentrations of credit risk and of significant suppliers	Concentrations of credit risk and of significant suppliers Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash and cash equivalents. The Company maintains its cash and cash equivalents in financial institutions in amounts that could exceed government-insured limits. The Company does not believe it is subject to additional credit risks beyond those normally associated with commercial banking relationships. The Company is dependent on third-party manufacturers to supply products for research and development activities in its programs. In particular, the Company relies and expects to continue to rely on a small number of manufacturers to supply its requirements for supplies and raw materials related to these programs. These programs could be adversely affected by a significant interruption in these manufacturing services or the availability of raw materials.
Cash and cash equivalents	Cash and cash equivalents The Company considers all highly liquid investments with original maturities of three months or less at date of purchase to be cash equivalents. The Company had no cash equivalents on December 31, 2020, and 2019.
Property, plant and equipment	Property, plant and equipment Property, plant and equipment are stated at cost, less accumulated depreciation . Depreciation expense is recognized using the straight-line method over the estimated useful lives of the respective assets as follows: Estimated Useful Economic Life Leasehold property improvements, right of use assets Lesser of lease term or useful life Laboratory equipment 5 years Furniture and office equipment 3 years construction-in-progress
Impairment of long-lived assets	Impairment of long-lived assets Long-lived assets consist of property, plant and equipment, goodwill, and intangible assets. 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 industry or economic trends and significant changes or planned changes in the use of the assets. An impairment loss would be recognized as a loss from operations when estimated undiscounted future cash flows expected to result from the use of an asset group or the estimated return on investment 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 flow or return on investment calculations. The Company recorded an impairment loss on long-lived assets of $4.2 million during the year ended December 31, 2019.
Business Combinations and Goodwill	Business Combinations and Goodwill Business combinations are accounted for in accordance with ASC Topic 805 “Business Combinations”. The total purchase price of an acquisition is allocated to the underlying identifiable net assets, based on their respective estimated fair values as of the acquisition date. Determining the fair value of assets acquired and liabilities assumed requires management’s judgment and often involves the use of significant estimates and assumptions, Required annual testing of goodwill for impairment was completed as of December 31, 20 20
Contingent value rights	Contingent value rights The acquisition-date fair value of the contingent valuation rights liability represents the future payments that are contingent upon the achievement of sale or licencing for the STING product candidates. The fair value of the contingent value rights is based on the Company’s probability-weighted discounted cash flow assessment that considers probability and timing of future payments. The fair value measurement is based on significant Level 3 unobservable inputs such as the probability of achieving a sale or licensing agreement, anticipated timelines, and discount rate. Changes in the fair value of the liability will be recognized in the consolidated statement of operations and comprehensive loss until settlement.
Acquired In-Process Research and Development (IPR&D)	Acquired In-Process Acquired IPR&D represents the fair value assigned to research and development assets that the Company acquires and have not been completed at the acquisition date. The fair value of IPR&D acquired in a business combination is recorded on the consolidated balance sheets at the acquisition-date fair value and is determined by estimating the costs to develop the technology into commercially viable products, estimating the resulting revenue from the projects, and discounting the projected net cash flows to present value. IPR&D is not amortized, but rather is reviewed for impairment on an annual basis or more frequently if indicators of impairment are present, until the project is completed, abandoned or transferred to a third party. The projected discounted cash flow models used to estimate the fair value of partnered assets and cost approach model used to estimate proprietary assets as part of the Company’s IPR&D reflect significant assumptions regarding the estimates a market participant would make in order to evaluate a drug development asset, including the following: • Estimates of obsolescence of development expenditure; • Probability of successfully completing clinical trials and obtaining regulatory approval; • Estimates of future cash flows from potential milestone payments and royalties related to out-licensed • A discount rate reflecting the Company’s weighted average cost of capital and specific risk inherent in the underlying assets. Once brought into use, intangible assets are amortized over their estimated useful economic lives, which for acquired IPR&D assets is over the remaining life of the relevant patents.
Fair value measurements of financial instruments	Fair value measurements of financial instruments The Company’s financial instruments consist of cash, accounts payable, CVR and liability classified warrants. The carrying amounts of cash and accounts payable approximate their fair value due to the short-term nature of those financial instruments. The fair value of CVR and the liability classified warrants are remeasured to fair value each reporting period. 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. Accounting Standards Codification (“ASC”) Topic 820, Fair Value Measurement (“ASC 820”), establishes a fair value hierarchy for instruments measured at fair value that distinguishes between assumptions based on market data (observable inputs) and the Company’s own assumptions (unobservable inputs). Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the inputs that market participants would use in pricing the asset or liability and are developed based on the best information available in the circumstances. ASC 820 identifies fair value as the exchange price, or exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As a basis for considering market participant assumptions in fair value measurements, ASC 820 establishes a three-tier fair value hierarchy that distinguishes between the following: • 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 that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The carrying amounts reflected in the consolidated balance sheets for cash and cash equivalents, and other current assets, research and development incentives receivable, accounts payable and accrued liabilities and other current liabilities approximate their fair values, due to their short-term nature.
Segment and geographic information	Segment and geographic information Operating segments are defined as components of a business for which separate discrete financial information is available for evaluation by the chief operating decision maker in deciding how to allocate resources and assess performance. The Company and its chief operating decision maker, the Company’s Chief Executive Officer, view the Company’s operations and manage its business as a single operating segment. The Company operates in three geographic areas: the United Kingdom, United States and Austria.
Leases	Leases The Company determines if an arrangement is a lease at inception. Operating leases are included in operating lease right-of-use ROU assets represent the Company’s right to use and control an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. ROU assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. As the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. The ROU asset also includes lease payments made before the lease commencement date and excludes any lease incentives. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. The components of a lease shall be split into three categories, if applicable: lease components (e.g., land, building, etc.), non-lease non-components in-substance non-components) non-lease non-lease non-lease right-of-use
License and collaboration arrangements and revenue recognition	License and collaboration arrangements and revenue recognition The Company’s revenues are generated primarily through license and collaboration agreements with pharmaceutical and biotechnology companies. The terms of these arrangements may include (i) the grant of intellectual property rights (IP licenses) to therapeutic drug candidates against specified targets, developed using the Company’s proprietary mAb 2 The terms of these arrangements typically include payment to the Company of one or more of the following: non-refundable, The Company has adopted Financial Accounting Standards Board (the “FASB”) Accounting Standards Codification (“ASC”) Topic 606—Revenue from Contracts with Customers (“ASC 606”). This standard applies to all contracts with customers, except for contracts that are within the scope of other standards, such as leases, insurance, collaboration arrangements and financial instruments. To date, the Company has entered into License and Collaboration Agreements with Denali Therapeutics, Inc., and Ares Trading S.A. (an affiliate of Merck KGaA, Darmstadt, Germany) which were determined to be within the scope of ASC 606. Under ASC 606, an entity recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. In determining the appropriate amount of revenue to be recognized under ASC 606, the Company performs the following steps: (i) identify the promised goods or services in the contract; (ii) determine whether the promised goods or services are performance obligations including whether they are distinct in the context of the contract; (iii) measurement of the transaction price, including the constraint on variable consideration; (iv) allocation of the transaction price to the performance obligations; and (v) recognition of revenue when (or as) the Company satisfies each performance obligation. As part of the accounting for these arrangements, the Company must make significant judgments, including identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each performance obligation. Once a contract is determined to be within the scope of ASC 606, the Company assesses the goods or services promised within the contract and determines those that are performance obligations. Arrangements that include rights to additional goods or services that are exercisable at a customer’s discretion are generally considered options. The Company assesses if these options provide a material right to the customer and if so, they are considered performance obligations. Performance obligations are promised goods or services in a contract to transfer a distinct good or service to the customer. The promised goods or services in the Company’s contracts with customers primarily consist of license rights to the Company’s intellectual property for research and development, research and development services, options to acquire additional research and development services, and options to obtain additional licenses, such as a commercialization license for a potential product candidate. Promised goods or services are considered distinct when: (i) the customer can benefit from the good or service on its own or together with other readily available resources; and (ii) the promised good or service is separately identifiable from other promises in the contract. In assessing whether promised goods or services are distinct, the Company considers factors such as the stage of development of the underlying intellectual property, the capabilities of the customer to develop the intellectual property on their own and whether the required expertise is readily available. In addition, the Company considers whether the collaboration partner can benefit from a promise for its intended purpose without the receipt of the remaining promises, whether the value of the promise is dependent on the unsatisfied promises, whether there are other vendors that could provide the remaining promises, and whether it is separately identifiable from the remaining promises. The Company estimates the transaction price based on the amount of consideration the Company expects to receive for transferring the promised goods or services in the contract. The consideration may include both fixed consideration and variable consideration. At the inception of each arrangement that includes variable consideration, the Company evaluates the amount of the potential payments and the likelihood that the payments will be received. The Company utilizes either the most likely amount method or expected value method to estimate variable consideration to include in the transaction price based on which method better predicts the amount of consideration expected to be received. The amount included in the transaction price is constrained to the amount for which it is probable that a significant reversal of cumulative revenue recognized will not occur. At the end of each subsequent reporting period, the Company re-evaluates catch-up After the transaction price is determined it is allocated to the identified performance obligations based on the estimated standalone selling price. The Company must develop assumptions that require judgment to determine the standalone selling price for each performance obligation identified in the contract. The Company utilizes key assumptions to determine the standalone selling price, which may include other comparable transactions, pricing considered in negotiating the transaction, probabilities of technical and regulatory success and the estimated costs. Certain variable consideration is allocated specifically to one or more performance obligations in a contract when the terms of the variable consideration relate to the satisfaction of the performance obligation and the resulting amounts allocated to each performance obligation are consistent with the amounts the Company would expect to receive for each performance obligation. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) each performance obligation is satisfied at a point in time or over time, and if over time based on the use of an input method. The Company accounts for contract modifications as a separate contract if both of the following conditions are met: (i) the scope of the contract increases because of the addition of promised goods or services that are distinct; and (ii) the price of the contract increases by an amount of consideration that reflects standalone selling prices of the additional promised goods or services and any appropriate adjustments to that price to reflect the circumstances of the particular contract. If a contract modification is deemed to not be a separate contract, then the transaction price is updated and allocated to the remaining performance obligations (both from the existing contract and the modification). Previously recognized revenue for goods and services that are not distinct from the modified goods or services is adjusted based upon an updated measure of progress for the partially satisfied performance obligations. If a contract modification is deemed to be a separate contract, any revenue recognized under the original contract is not retrospectively adjusted and any performance obligations remaining under the original contract continue to be recognized under the terms of that contract. The Company’s collaboration revenue arrangements include the following: Up-front up-front non-refundable, up-front Milestone payments: The Company’s collaboration agreements may include development and regulatory milestones. The Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. The Company evaluates factors such as the scientific, clinical, regulatory, commercial, and other risks that must be overcome to achieve the particular milestone in making this assessment. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the Company’s control or the licensee’s control, such as regulatory approvals, are not considered probable of being achieved until those approvals are received. At the end of each reporting period, the Company re-evaluates catch-up Customer Options: The Company evaluates the customer options to obtain additional items (i.e., additional license rights) for material rights, or options to acquire additional goods or services for free or at a discount. Optional future services that reflect their standalone selling prices do not provide the customer with a material right and, therefore, are not considered performance obligations and are accounted for as separate contracts. If optional future services include a material right, they are accounted for as performance obligations. The Company determines an estimated standalone selling price of any material rights for the purpose of allocating the transaction price. The Company considers factors such as the identified discount and the probability that the customer will exercise the option. Amounts allocated to a material right are not recognized as revenue until, at the earliest, the option is exercised or expires. Royalties: For arrangements that include sales-based royalties, including milestone payments based on a level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company will recognize revenue at the later of Research and Development Services: The promises under the Company’s collaboration agreements may include research and development services to be performed by the Company on behalf of the partner. Payments or reimbursements resulting from the Company’s research and development efforts are recognized as the services are performed and presented on a gross basis because the Company is the principal for such efforts.
Research and development costs	Research and development costs Research and development costs are expensed as incurred. Research and development expenses are comprised of costs incurred in performing research and development activities, including salaries, share-based compensation and benefits, facilities costs and laboratory supplies, depreciation, amortization and impairment expense, manufacturing expenses and external costs of outside vendors engaged to conduct preclinical development activities and clinical trials as well as the cost of licensing technology. Typically, upfront payments and milestone payments made for the licensing of technology are expensed as research and development in the period in which they are incurred, except for payments relating for intellectual property rights with future alternative use which will be expensed when the intellectual property is in use. Nonrefundable 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.
Research contract costs and accruals	Research contract costs and accruals The Company has entered into various research and development contracts with companies both inside and outside of the United States. These agreements are generally cancelable, and related payments are recorded as research and development expenses as incurred. The Company records accruals for estimated ongoing research costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the studies or trials, 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.
Research and development incentives and receivable	Research and development incentives and receivable The Company, through its subsidiaries in the United Kingdom, receives reimbursements of certain research and development expenditures as part of a United Kingdom government’s research and development tax reliefs program. Under the program, the Company is able to surrender trading losses that arise from qualifying research and development expenses incurred in the United Kingdom for a tax credit of up to 14.5% of the surrender able losses. Management has assessed the Company’s research and development activities and expenditures to determine which activities and expenditures are likely to be eligible under the research and development incentive program described above. At each period end, management estimates the reimbursement available to the Company based on available information at the time. The Company recognizes income from the research and development incentives when the relevant expenditure has been incurred, the associated conditions have been satisfied and there is reasonable assurance that the reimbursement will be received. The Company records these research and development incentives as a reduction to research and development expenses in the consolidated statements of operations and comprehensive loss, as the research and development tax credits are not dependent on the Company generating future taxable income, the Company’s ongoing tax status, or tax position. The research and development incentives receivable represent an amount due in connection with the above program. The Company recorded a reduction to research and development expense of $3.3 million and $6.6 million for the year ended December 31, 2020 and 2019, respectively.
Patent costs	Patent costs All patent-related costs incurred in connection with preparing, filing and prosecuting patent applications are expensed as incurred due to the uncertainty about the recovery of the expenditure. Amounts incurred are classified as general and administrative expenses in the consolidated statements of operations and comprehensive loss.
Warrants	Warrants The Company accounts for freestanding warrants within stockholder’s equity or as liabilities based on the characteristics and provisions of each instrument. The Company evaluates outstanding warrants in accordance with Accounting Standards Codification (“ASC”) 480, Distinguishing Liabilities from Equity Derivatives and Hedging
Share-based compensation	Share-based compensation The Company accounts for share-based compensation in accordance with ASC 718, ‘Compensation – Stock Compensation”(“ASC 718”). ASC 718 requires companies to estimate the fair value of equity-based payment awards on the date of grant. The value of the portion of the award that is ultimately expected to vest is recognized as an expense over the requisite service period in the Company’s consolidated statements of operations and comprehensive loss. The Company records the expense for option awards using a graded vesting method. The Company accounts for forfeitures as they occur. For share-based awards granted to non-employee non-employee The Company reviews stock award modifications when there is an exchange of original award for a new award. The Company calculates for the incremental fair value based on the difference between the fair value of the modified award and the fair value of the original award immediately before it was modified. The Company immediately recognizes the incremental value as compensation cost for vested awards and recognizes, on a prospective basis over the remaining requisite service period, the sum of the incremental compensation cost and any remaining unrecognized compensation cost for the original award on the modification date. The fair value of stock options (“options”) on the grant date is estimated using the Black-Scholes option-pricing model using the single-option approach. The Black-Scholes option pricing model requires the use of highly subjective and complex assumptions, including the option’s expected term and the price volatility of the underlying stock, to determine the fair value of the award. Historically given the absence of an active market for the ordinary shares of F-star F-star commensurate with the expected term assumption. F-star F-star The Company uses the remaining contractual term for the expected life of non-employee The Company classifies share-based compensation expense in its consolidated statements of operations and comprehensive loss in the same manner in which the award recipient’s payroll costs are classified or in which the award recipient’s service payments are classified.
Comprehensive loss	Comprehensive loss Comprehensive loss includes net loss as well as other changes in shareholders’ equity (deficit) that result from transactions and economic events other than those with shareholders. The Company records unrealized gains and losses related to foreign currency translation as a component of other comprehensive loss in the consolidated statements of operations and comprehensive loss.
Contingencies	Contingencies Liabilities for loss contingencies arising from claims, assessments, litigation, fines, penalties and other sources are recorded when it is probable that a liability has been incurred and the amount can be reasonably estimated. At each reporting date, the Company evaluates whether or not a potential loss amount or a potential loss range is probable and reasonably estimable under the provisions of the authoritative guidelines that address accounting for contingencies. The Company expenses costs as incurred in relation to such legal proceedings as general and administrative expense within the consolidated statements of operations and comprehensive loss.
Income taxes	Income taxes The Company accounts for income taxes using 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 recognized in the consolidated financial statements or in the Company’s tax returns. Deferred tax assets and liabilities are determined on the basis of the differences between the consolidated financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Changes in deferred tax assets and liabilities are recorded in the provision for income taxes. 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 two-step more-likely-than-not Research and development tax credits received in the U.K. are recorded as a reduction to research and development expenses. The U.K. research and development tax credit is payable to the Company after
Net loss per share	Net loss per share The Company computes net (loss) income per share in accordance with ASC Topic 260, ”Earnings Per Share”(“ASC 260”) and related guidance, which requires two calculations of net (loss) income attributable to the Company’s shareholders per share to be disclosed: basic and diluted. Convertible preferred shares are participating securities and are included in the calculation of basic and diluted net (loss) income per share using the two-class Diluted net (loss) income per share is the same as basic net (loss) income per share for the periods in which the Company had a net loss because the inclusion of outstanding common stock equivalents would be anti-dilutive.
Recently adopted accounting pronouncements	Recently adopted accounting pronouncements In August 2018, the FASB issued ASU No. 2018-13, 2018-13), In June 2016, the FASB issued ASU No. 2016-13, 2016-13”). 2016-13 held-to-maturity In November 2018, the FASB issued ASU No. 2018-18, • Clarifies that certain transactions between collaborative arrangement participants should be accounted for as revenue under ASC 606, Revenue from Contracts with Customers, when the collaborative arrangement participant is a customer in the context of a unit of account. In those situations, all the guidance in ASC 606 should be applied, including recognition, measurement, presentation and disclosure requirements: • Adds unit-of-account • Precludes a company from presenting transactions with collaborative arrangement participants that are not directly related to sales to third parties with revenue recognized under ASC 606 if the collaborative arrangement participant is not a customer. This standard became effective for the Company on January 1, 2020. The adoption of this standard did not have a material impact on our consolidated financial statements.
Recently Issued Accounting Pronouncements	Recently issued accounting pronouncements In December 2019, the FASB issued ASU No. 2019-12,

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Property Plant and Equipment Useful lives	Depreciation expense is recognized using the straight-line method over the estimated useful lives of the respective assets as follows: Estimated Useful Economic Life Leasehold property improvements, right of use assets Lesser of lease term or useful life Laboratory equipment 5 years Furniture and office equipment 3 years

Business Combination (Tables)

Business Combination (Tables)	12 Months Ended
	Dec. 31, 2020
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest [Abstract]
Summary of Purchase Price is Allocated to the Fair Value of Assets and Liabilities Acquired	For the year ended December 31, 2020, the Company incurred acquisition-related expenses of approximately $4.2 million which are included in general and administrative expenses. The purchase price is allocated to the fair value of assets and liabilities acquired as follows (in thousands, except common shares and fair value per share): Number of full common shares 4,449,559 Multiplied by fair value per share of common stock $ 4.84 Purchase price $ 21,536 Cash and cash equivalents $ 9,779 Marketable securities 5,000 Prepaid expenses and other assets 935 Operating lease right of use asset 2,784 Intangible assets 4,720 Goodwill 10,451 Accounts payable, accrued expenses and other liabilities (5,453 ) Contingent value rights (2,520 ) Liability and equity based warrants (422 ) Deferred tax liability (576 ) Operating lease liability (3,162 ) Fair value of net assets acquired $ 21,536

2019 Corporate Reorganization (

2019 Corporate Reorganization (Tables)	12 Months Ended
	Dec. 31, 2020
Restructuring Cost and Reserve [Line Items]
Summary of Assets and Liabilities Recognized as a result of Beta Acquisition	For the year ended December 31, 2020, the Company incurred acquisition-related expenses of approximately $4.2 million which are included in general and administrative expenses. The purchase price is allocated to the fair value of assets and liabilities acquired as follows (in thousands, except common shares and fair value per share): Number of full common shares 4,449,559 Multiplied by fair value per share of common stock $ 4.84 Purchase price $ 21,536 Cash and cash equivalents $ 9,779 Marketable securities 5,000 Prepaid expenses and other assets 935 Operating lease right of use asset 2,784 Intangible assets 4,720 Goodwill 10,451 Accounts payable, accrued expenses and other liabilities (5,453 ) Contingent value rights (2,520 ) Liability and equity based warrants (422 ) Deferred tax liability (576 ) Operating lease liability (3,162 ) Fair value of net assets acquired $ 21,536
Summary of Intangible Aseets Acquired	The intangible assets acquired with Beta are summarized in the table below (in thousands): FV Description FS21 $ 4,426 Contracted future cash flows relating to a drug candidate that has been licensed to a collaboration partner FS120 6,359 Internally developed drug candidate, for which Beta holds the IP rights FS222 5,173 Internally developed drug candidate, for which Beta holds the IP rights $ 15,958
Beta [Member]
Restructuring Cost and Reserve [Line Items]
Summary of Assets and Liabilities Recognized as a result of Beta Acquisition	The assets and liabilities recognized as a result of the acquisition of Beta are as follows (in thousands): Cash and cash equivalents $ 1,205 Other current assets 5,475 In-process 15,958 Goodwill 2,293 Current liabilities (19,376 ) $ 5,555
Summaty of Results of Operations	The following unaudited supplemental pro forma information summarizes the results of operations of Beta as if the acquisition had occurred on January 1, 2018: Period from 2019 Revenue $ — Net loss (5,549 )
GmbH Group [Member]
Restructuring Cost and Reserve [Line Items]
Summary of Assets and Liabilities Recognized as a result of Beta Acquisition	The assets and liabilities recognized as a result of the acquisition of GmbH Group are as follows (in thousands): Cash $ 952 Other current assets 18,211 Property and equipment 1,965 Right of use assets 975 In process research and development 1,436 Equity investment 56 Current liabilities (15,751 ) Other non-current (466 ) Goodwill 2,044 $ 9,422 The acquisition of GmbH Group contributed revenue of $2.4 million and a loss of $14.6 million to the Company’s results from May 7, 2019 through December 31, 2019. The goodwill is attributable to the workforce and will not be deductible for tax purposes.
Summaty of Results of Operations	The following unaudited supplemental pro forma information summarizes the results of operations of GmbH as if the acquisition had occurred on January 1, 2018: Period from 2019 Revenue $ 1,811 Net (loss) income $ (6,880 )

Prepaid expenses and other cu_2

Prepaid expenses and other current assets (Tables)	12 Months Ended
	Dec. 31, 2020
Prepaid Expense and Other Assets, Current [Abstract]
Summary of Prepaid Expenses and other Current Assets	Prepaid expenses and other current assets on December 31, 2020, and 2019 consist of the following (in thousands): 2020 2019 Research and Development $ 526 $ 1,382 Rent 705 220 Clinical Trial Costs 846 204 License Fees — 608 VAT recoverable 443 842 Insurance 277 — Refunds due 420 — Other 759 332 $ 3,976 $ 3,588

Property, plant and equipment_2

Property, plant and equipment, net (Tables)	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment	Property, plant and equipment, net consisted of the following (in thousands): 2020 2019 Leasehold improvements $ 15 $ 14 Laboratory equipment 1,788 1,725 Furniture and office equipment 169 194 1,972 1,933 Less: Accumulated depreciation 1,183 508 $ 789 $ 1,425

Goodwill and In-process Resea_2

Goodwill and In-process Research and Development (Tables)	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill and In Process Research and Development	The changes in the carrying amount of Goodwill and In-process Goodwill In-process Amount acquired as of May 7, 2019 $ 4,337 17,395 Capitalized — 127 Impairments during the year — (4,152 ) Effect of changes in exchange rate used for translation (17 ) (321 ) Balance at December 31, 2019 $ 4,320 $ 13,049 Capitalized — 730 Acquired by the Transaction 10,451 4,720 Effect of changes in exchange rate used for translation 155 487 Balance at December 31, 2020 $ 14,926 $ 18,986

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Summary of Assets and Liabilities Measured at Fair Value	The following tables present information about the Company’s financial assets and liabilities measured at fair value on a recurring basis and indicate the level of the fair value hierarchy utilized to determine such fair values (in thousands): Fair Value Measurements as of Level 1 Level 2 Level 3 Total Liabilities: Contingent value rights $ — $ — $ 2,520 $ 2,520 Warrants — — 37 37 $ — $ — $ 2,557 $ 2,557 Fair Value Measurements as of Level 1 Level 2 Level 3 Total Liabilities: Convertible notes $ — $ — $ 14,906 $ 14,906
Summary of Change in Company's Level 3 Liabilities, Warrants Issued in a Private Placement	The following table reflects the change in the Company’s Level 3 liabilities, which consists of the liability based warrants outstanding as of November 20, 2020 through December 31, 2020 (in thousands): November Private Fair value of liability based warrants outstanding as of November 20, 2020 $ 221 Warrants exercised (184 ) Balance at December 31, 2020 $ 37

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2020
Payables and Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses at December 31, 2020 and 2019 2020 2019 Clinical Trial Costs $ 3,394 $ 5,892 Severance 1,953 — Compensation and Benefits 1,361 1,190 Professional Fees 1,593 1,305 Payroll taxes — 257 Other 1,160 232 $ 9,461 $ 8,876

Convertible Notes (Tables)

Convertible Notes (Tables)	12 Months Ended
	Dec. 31, 2020
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Summary of roll-forward of the fair values of the Company's convertible note for which fair value was determined by Level 3 inputs	The following table reflects the change in the Company’s Level 3 liabilities, which consists of the liability based warrants outstanding as of November 20, 2020 through December 31, 2020 (in thousands): November Private Fair value of liability based warrants outstanding as of November 20, 2020 $ 221 Warrants exercised (184 ) Balance at December 31, 2020 $ 37
Convertible notes
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Summary of roll-forward of the fair values of the Company's convertible note for which fair value was determined by Level 3 inputs	The following table provides a roll-forward of the fair values of the Company’s convertible note for which fair value was determined by Level 3 inputs (in thousands): Convertible notes at fair value Balance on December 31, 2019 $ 14,906 Proceeds from issuance 850 Interest 978 Effects of foreign exchange 29 Fair value gain 2,386 Conversion of notes to equity (19,149 ) Fair value at December 31, 2020 $ —

Warrants (Tables)

Warrants (Tables)	12 Months Ended
	Dec. 31, 2020
Warrants and Rights Note Disclosure [Abstract]
Summary of Assumptions Used to Record Fair Value of Warrants	A summary of the Black-Scholes pricing model assumptions used to record the fair value of the warrants is as follows: 2020 Risk-free interest rate 1.9 % Expected term (in years) 0.9 Expected volatility 100.0 % Expected dividend yield 0 %
Summary of Warrant Activity	A summary of the warrant activity for the Company since the Closing Date of the Transaction to the year ended December 31, 2020 is as follows: Warrants Warrant outstanding as of November 20, 2020 481,781 Exercises (337,397 ) Outstanding at December 31, 2020 144,384

Stock Option Plans (Tables)

Stock Option Plans (Tables)	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Summary of Stock Option Valuation	The fair value of stock option grants is estimated using the Black-Scholes option-pricing model with the following assumptions:. 2020 2019 Risk-free interest rate 0.17% - % 1.74% - % Expected volatility 82.8% - % 70.03 - 70.31 % Expected dividend yield 0 % 0 % Expected life (in years) 5.1 5.1
Summary of Option Activity	Number of Weighted Weighted Average Aggregate Intrinsic (in years) (in thousands) Balance on December 31, 2019 259,148 $ 7.07 9.24 $ 4,334 Granted 415,343 0.20 — — Exercised (42,260 ) 0.10 — — Forfeited (28,883 ) 4.79 — — Outstanding as of December 31, 2020 603,348 $ 2.94 9.30 $ 8,494 Options exercisable at December 31, 2020 89,957 $ 9.24 8.70 $ 1,228
Summary of Stock-Based Compensation Expense	The Company recorded share-based compensation expense in the following expense categories for the year ended December 31, 2020 and 2019 of its consolidated statements of operations and comprehensive loss (in thousands): 2020 2019 Research and development expenses $ 684 $ 554 General and administrative expenses 2,805 2,115 $ 3,489 $ 2,669

Significant agreements (Tables)

Significant agreements (Tables)	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of License and Collaboration Agreements	For the years ended December 31, 2020 and 2019, the Company had License and Collaboration agreements (“LCA”s) with Denali Therapeutics Inc. (“Denali”) and Ares Trading S.A (“Ares”). The following table summarizes the revenue recognized in the Company’s consolidated statements of operations and comprehensive loss from these arrangements, (in thousands): Year Ended 2020 2019 Collaboration revenues Ares (Switzerland) $ 9,930 $ 25,871 Denali (US) 1,326 2,450 Total collaboration revenues $ 11,256 $ 28,321
Summary of Contract Assets and Liabilities	The following table presents changes in the balances of the Company’s contract assets and liabilities (in thousands): Year ended December 31, 2020 Balance at Additions Recognized Impact of Balance at Contract liabilities: Ares collaboration $ 33 $ 37 $ (33 ) $ — $ 37 Denali collaboration 409 — (151 ) 5 263 Total deferred revenue $ 442 $ 37 $ (184 ) $ 5 $ 300 Year ended December 31, 2019 Balance at Acquired with Additions Recognized Impact of Balance at Contract liabilities: Ares collaboration $ 5,824 $ — $ — $ (5,903 ) $ 112 $ 33 Denali collaboration — 869 31 (473 ) (18 ) 409 Total deferred revenue $ 5,824 $ 869 $ 31 $ (6,376 ) $ 94 $ 442

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Schedule of Income before Income Tax, Domestic and Foreign	The components of net (loss)/profit before tax provision from income taxes are as follows (in thousands): Year Ended 2020 2019 United Kingdom $ (24,490 ) $ (20,943 ) Austria 315 (62 ) United States (1,445 ) (2,745 ) Total $ (25,620 ) $ (23,750 )
Schedule of Components of Income Tax Expense (Benefit)	The components of the benefit for income taxes are as follows (in thousands): Year Ended 2020 2019 Federal $ (41 ) $ (152 ) State — (7 ) Foreign 42 — Total current income tax (provision) benefit 1 (159 ) Total deferred income tax (benefit) — 896 Total benefit from income taxes $ 1 $ 737
Reconciliation of Statutory U.S. Federal Tax Rate with Effective Tax Rate	Year Ended 20 20 201 9 Income tax (provision) benefit at statutory rate 21.0 % 19.0 % Expenses not deductible (9.4 %) (8.5 %) Net losses surrendered for U.K. R&D tax credit (4.6 %) (10.3 %) Change in valuation allowance (7.1 %) 3.8 % Foreign rate differential (1.5 %) (0.1 %) Adjustment in respect to 1.6 % (0.8 %) Actual income tax expense effective tax rate 0.0 % 3.1 %
Components of Deferred Tax Assets	Significant components of the Company’s current and deferred tax assets (liabilities) as at December 31, 2020 and 2019, were as follows (in thousands): Year Ended 2020 2019 Deferred tax assets: Net operating loss carryforwards $ 45,053 $ Research and development credit carryforwards 957 — Capitalized R&D expenditures 5,238 — Lease Obligation 860 — Stock option expense 1,206 742 Other 18 — Total gross deferred $ 53,332 $ 10,145 Valuation Allowance (49,304 ) (7,607 ) Net deferred tax assets 4,028 2,538 Deferred tax liabilities: Acquired Intangibles (3,763 ) (2,205 ) Right of Use Assets (769 ) — Capital Allowances (72 ) (333 ) Net deferred tax liability $ (576 ) $ —

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Summary of Computation of Basic and Diluted Net Loss Per Share	The following table summarizes the computation of basic and diluted net loss per share of the Company for such years 2020 2019 Net loss $ (25,619 ) $ (23,013 ) Weighted average number shares outstanding, basic and diluted 2,643,175 1,545,177 Net loss income per common, basic and diluted $ (9.69 ) $ (14.89 )

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Summary of Maturities of Operating Lease Liabilities	The following table summarizes the Company’s maturities of operating lease liabilities as of December 31, 2020 (in thousands): Year 2021 $ 542 2022 451 2023 462 2024 474 2025 486 Thereafter 1,444 Total lease payments $ 3,859
Summary of Future expected cash receipts from subleases	Future expected cash receipts from subleases as of December 31, 2020 is as follows Year 2021 $ 83 2022 462 2023 474 2024 486 2025 498 Thereafter 1,482 Total sublease receipts $ 3,485

Related Party Transactions 20_2

Related Party Transactions 2019 Reorganization (Tables)	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement, Disclosure [Abstract]
Summary of Related Party Transactions	Transactions in the year ended December 31, 2019 with Beta and F-star 2019 R&D Other Expenses Beta $ 2,126 $ 552 F-star 235 — GmbH — 13

Nature of the business - Additi

Nature of the business - Additional Information (Details)	Nov. 20, 2020USD ($)$ / sharesshares	Dec. 31, 2020USD ($)	Dec. 31, 2020GBP (£)	Dec. 31, 2019USD ($)	May 07, 2019
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Stockholders' Equity, Reverse Stock Split	1-for-4
Stock Issued During Period, Value, Acquisitions		$ 55,781,000
Stock Issued During Period, Shares, Reverse Stock Splits | shares	4,449,559
Contingent Consideration Liability		2,500,000
Cash		$ 18,526,000		$ 4,901,000
Percentage of Voting Interests Acquired					100.00%
Defined contribution maximum contribution percentage per furloughed employees		80.00%	80.00%
Defined contribution maximum contribution amount per month per furloughed employees | £			£ 2,500
Contingent Value Rights Agreement [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Percentage Of Net Proceeds	25.00%
Product Price | $ / shares	$ 1
Target Payment Amount	$ 18,000,000
Pre Closing Financing [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Proceeds from Issuance of Common Stock	15,000,000
Spring Bank [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Stock Issued During Period, Value, Acquisitions	$ 4,620,618
Share Exchange Price Per Share | $ / shares	$ 0.1125
Ownership Percentage by parent	53.70%
Minority Interest Ownership Percentage	46.30%
Share Transfer Lock In Period	180 days
Contingent Consideration Liability		$ 2,500,000

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Summary of Property Plant and Equipment Useful lives (Detail)	12 Months Ended
	Dec. 31, 2020
Leasehold Improvements And Right Of Use Assets [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	Lesser of lease term or useful life
Laboratory Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Furniture And Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Gain loss on foreign currency translation	$ 0.4	$ 0.3
Cash equivalents	$ 0	0
Impairment of long-lived assets		$ 4.2
UNITED KINGDOM
Business Acquisition [Line Items]
Research And Development Tax Credit Percentage	14.50%	14.50%
Research and Development Expense [Member] | UNITED KINGDOM
Business Acquisition [Line Items]
Research and development incentive	$ 3.3	$ 6.6

Going Concern - Additional info

Going Concern - Additional information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Going Concern [Abstract]
Accumulated deficit	$ 47,168	$ 21,549
significant conditions or events effecting Going concern	F-star expects to incur substantial losses in the foreseeable future as it conducts and expands its research and development activities. As of March 30, 2021, the date of issuance of the consolidated financial statements, the Company’s current cash deposits will not be sufficient to fund its current operating plan and planned capital expenditures for at least the next 12 months. These conditions give rise to a substantial doubt over the Company’s ability to continue as a going concern.

Business Combination - Summary

Business Combination - Summary of Purchase Price is Allocated to the Fair Value of Assets and Liabilities Acquired (Detail) - USD ($) $ / shares in Units, $ in Thousands	Nov. 20, 2020	Dec. 31, 2020	Dec. 31, 2019	May 06, 2019
Business Acquisition [Line Items]
Goodwill		$ 14,926	$ 4,320	$ 4,337
Contingent value rights		$ (440)	$ 0
Spring Bank [Member]
Business Acquisition [Line Items]
Number of full common shares		4,449,559
Multiplied by fair value per share of common stock		$ 4.84
Purchase price	$ 21,500	$ 21,536
Cash and cash equivalents		9,779
Marketable securities		5,000
Prepaid expenses and other assets		935
Operating lease right of use asset		2,784
Intangible assets		4,720
Goodwill		10,451
Accounts payable, accrued expenses and other liabilities		(5,453)
Contingent value rights		(2,520)
Liability and equity based warrants		(422)
Deferred tax liability		(576)
Operating lease liability		(3,162)
Fair value of net assets acquired		$ 21,536

Business Combination - Summar_2

Business Combination - Summary of Purchase Price is Allocated to the Fair Value of Assets and Liabilities Acquired (Parenthetical) (Detail) $ in Millions	Dec. 31, 2020USD ($)
Business Acquisition [Line Items]
Business Combination, Contingent Consideration, Liability	$ 2.5
Spring Bank [Member]
Business Acquisition [Line Items]
Business Combination, Contingent Consideration, Liability	2.5
Business combination contingent consideration liability maximum	$ 26

Business Combination - Addition

Business Combination - Additional Information (Detail) - USD ($) $ in Thousands	Nov. 20, 2020	Dec. 31, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Net loss		$ (25,619)	$ (23,013)
Pro forma Net losses		47,100	$ 49,600
Spring Bank [member]
Business Acquisition [Line Items]
Consideration	$ 21,500	21,536
Net loss		$ 1,700
Business combination acquired in process and research and development assets acquired discount rate used in estimating the fair value		14.00%
Spring Bank [member] | Selling, General and Administrative Expenses [Member]
Business Acquisition [Line Items]
Business acquisition costs included in general and administrative expenses		$ 4,200
Spring Bank [member] | Equity Classified Warrants [member]
Business Acquisition [Line Items]
Warrants Outstanding	73,337
Fair value of equity warrants outstanding	$ 200
Spring Bank [member] | Liability Classified Warrants [member]
Business Acquisition [Line Items]
Warrants Outstanding	408,444
Fair value of liability warrants outstanding	$ 200

2019 Corporate Reorganization -

2019 Corporate Reorganization - Summary of Assets and Liabilities Recognized as a result of Beta Acquisition (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	May 07, 2019	May 06, 2019
Business Acquisition [Line Items]
Goodwill	$ 14,926	$ 4,320		$ 4,337
Beta [Member]
Business Acquisition [Line Items]
Cash and cash equivalents			$ 1,205
Other current assets			5,475
Other current assets			15,958
Goodwill			2,293
Current liabilities			(19,376)
Fair value of net assets acquired			$ 5,555

2019 Corporate Reorganization_2

2019 Corporate Reorganization - Summary of Results of Operations of Beta (Detail) - USD ($) $ in Thousands	4 Months Ended	12 Months Ended
	May 06, 2019	Dec. 31, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Net loss		$ 47,100	$ 49,600
Beta [Member]
Business Acquisition [Line Items]
Revenue	$ 0
Net loss	$ (5,549)

2019 Corporate Reorganization_3

2019 Corporate Reorganization - Summary of Intangible Assets Acquired (Detail) - Beta [Member] $ in Thousands	May 07, 2019USD ($)
Acquired Indefinite-lived Intangible Assets [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	$ 15,958
FS21 [Member]
Acquired Indefinite-lived Intangible Assets [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	$ 4,426
Description Of Intangible Assets Acquired	Contracted future cash flows relating to a drug candidate that has been licensed to a collaboration partner
FS120 [Member]
Acquired Indefinite-lived Intangible Assets [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	$ 6,359
Description Of Intangible Assets Acquired	Internally developed drug candidate, for which Beta holds the IP rights
FS 222 [Member]
Acquired Indefinite-lived Intangible Assets [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	$ 5,173
Description Of Intangible Assets Acquired	Internally developed drug candidate, for which Beta holds the IP rights

2019 Corporate Reorganization_4

2019 Corporate Reorganization - Summary of Assets and Liabilities Recognized as a Result of the Acquisition of GmbH Group (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	May 07, 2019	May 06, 2019
Business Acquisition [Line Items]
Goodwill	$ 14,926	$ 4,320		$ 4,337
GmbH Group [Member]
Business Acquisition [Line Items]
Cash			$ 952
Other current assets			18,211
Property and equipment			1,965
Right of use assets			975
In process research and development			1,436
Equity investment			56
Current liabilities			(15,751)
Other non-current liabilities			(466)
Goodwill			2,044
Fair value of net assets acquired			$ 9,422

2019 Corporate Reorganization_5

2019 Corporate Reorganization - Additional Information (Details) $ in Thousands	May 07, 2019USD ($)shares	Dec. 31, 2019USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Restructuring Cost and Reserve [Line Items]
Resrtructuring and related activities description	On May 7, 2019, F-star Ltd completed a corporate reorganization pursuant to which F-star Ltd became the direct holding company of each of Alpha, Beta, Delta, and GmbH and the indirect holding company of each of F-star Biotechnology Limited (“Biotech”), and F-star Therapeutics LLC (“LLC”) collectively, the “F-star Group Entities”. Prior to the transactions described below, all F-star Group entities were deemed not to be under common control but were deemed to be related parties due to common directorships.
Business Acquisition, Percentage of Voting Interests Acquired	100.00%
Net Loss			$ (25,619)	$ (23,013)
Revenue			$ 11,256	28,321
Delta [member]
Restructuring Cost and Reserve [Line Items]
Business acquisition ,Number of full common shares issued | shares	9,053,538
Business Acquisition Equity Interest Issued Ratio	1.1
Business Acquisition, Percentage of Voting Interests Acquired	100.00%
Net Loss				$ 4,800
Beta [Member]
Restructuring Cost and Reserve [Line Items]
Business acquisition ,Number of full common shares issued | shares	6,446,843
Net Loss		$ 12,400
Consideration	$ 5,600
GmbH Group [Member]
Restructuring Cost and Reserve [Line Items]
Business acquisition ,Number of full common shares issued | shares	125,715
Net Loss		14,600
Consideration	$ 9,400
Revenue		$ 2,400
GmbH Group [Member] | Preferred Class A [Member]
Restructuring Cost and Reserve [Line Items]
Business acquisition ,Number of full common shares issued | shares	1,441,418
GmbH Group [Member] | Seed Preferred Shares [Member]
Restructuring Cost and Reserve [Line Items]
Business acquisition ,Number of full common shares issued | shares	103,611
Alpha [Member]
Restructuring Cost and Reserve [Line Items]
Business acquisition ,Number of full common shares issued | shares	570,387
Consideration	$ 13,500

2019 Corporate Reorganization_6

2019 Corporate Reorganization - Summary of Results of Operations of GmbH (Detail) - USD ($) $ in Thousands	4 Months Ended	12 Months Ended
	May 06, 2019	Dec. 31, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Net (loss) income		$ 47,100	$ 49,600
GmbH Group [Member]
Business Acquisition [Line Items]
Revenue	$ 1,811
Net (loss) income	$ (6,880)

Prepaid expenses and other cu_3

Prepaid expenses and other current assets - Summary of Prepaid Expenses and other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Prepaid Expense, Current [Abstract]
Research and Development	$ 526	$ 1,382
Rent	705	220
Clinical Trial Costs	846	204
License Fees		608
VAT recoverable	443	842
Insurance	277
Refunds due	420
Other	759	332
Prepaid expenses and other current assets	$ 3,976	$ 3,588

Property and Equipment, Net - S

Property and Equipment, Net - Schedule of Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 1,972	$ 1,933
Less: accumulated depreciation	1,183	508
Property and equipment, net	789	1,425
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	15	14
Laboratory Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	1,788	1,725
Furniture and Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 169	$ 194

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 1,144	$ 844
Disposal of property,plant and machinery		$ 100

Goodwill and In-process Resea_3

Goodwill and In-process Research and Development - Schedule of Goodwill and In Process Research and Development (Details) - USD ($) $ in Thousands	8 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Balance	$ 4,337	$ 4,320
Acquired by the Transaction		10,451
Effect of changes in exchange rate used for translation	(17)	155
Balance	4,320	14,926
Balance	17,395	13,049
Capitalized	127	730
Impairments during the year	(4,152)
Acquired by merger		4,720
Effect of changes in exchange rate used for translation	(321)	487
Balance	$ 13,049	$ 18,986

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Assets and Liabilities Measured at Fair Value (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities, Total	$ 2,557
Contingent Value Rights [member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities, Total	2,520
Convertible notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities, Total		$ 14,906
Warrant Liabilities [member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities, Total	37
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities, Total	2,557
Level 3 | Contingent Value Rights [member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities, Total	2,520
Level 3 | Convertible notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities, Total		$ 14,906
Level 3 | Warrant Liabilities [member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities, Total	$ 37

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of change in the Company's Level 3 liabilities, liability based warrants outstanding (Detail) - Level 3 - Private Placement [Member] $ in Thousands	1 Months Ended
	Dec. 31, 2020USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Beginning balance	$ 221
Warrants exercised	(184)
Balance at December 31, 2020	$ 37

Fair Value Measurements - Addit

Fair Value Measurements - Additional information (Details) - USD ($) $ in Thousands	Nov. 20, 2020	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Jul. 19, 2020	Mar. 03, 2020	Nov. 27, 2019	Sep. 19, 2019
Fair Value Disclosures [Abstract]
Number of shares issued in conversion of convertible securities		1,445,779
Convertible notes	$ 19,200	$ 19,200	$ 19,200		$ 300	$ 600	$ 6,600	$ 6,600
Convertible debt interest	$ 1,000	1,000
Change in fair value of convertible debt		$ 2,400	$ 2,386	$ 1,450

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Accrued Liabilities and Other Liabilities [Abstract]
Accrued Clinical Trail Costs Current	$ 3,394	$ 5,892
Accrued Severance Costs	1,953
Compensation and Benefits	1,361	1,190
Professional Fees	1,593	1,305
Payroll taxes		257
Other	1,160	232
Total accrued expenses and other current liabilities	$ 9,461	$ 8,876

Convertible Notes - Summary of

Convertible Notes - Summary of Roll Forward of the Fair Values of the Company's Convertible Note by Level 3 inputs (Detail) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Proceeds from issuance		$ 850	$ 13,264
Fair value gain	$ 2,400	2,386	1,450
Level 3
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance		14,906
Proceeds from issuance		850
Interest		978
Effects of foreign exchange		29
Fair value gain		2,386
Conversion of notes to equity		(19,149)
Ending balance	$ 0	$ 0	$ 14,906

Convertible Notes - Additional

Convertible Notes - Additional Information (Detail) $ in Thousands	Nov. 20, 2020USD ($)	Dec. 31, 2020USD ($)shares	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Jul. 19, 2020USD ($)	Mar. 03, 2020USD ($)	Nov. 27, 2019USD ($)	Sep. 19, 2019USD ($)
Fair Value Disclosures [Abstract]
Convertible Notes interest rate								8.00%
Convertible notes	$ 19,200	$ 19,200	$ 19,200		$ 300	$ 600	$ 6,600	$ 6,600
Debt instrument convertible threshold raised trigger			$ 50,000
Embedded derivative measuring input		90	90
Number of shares issued in conversion of convertible securities | shares		1,445,779
Convertible debt interest	$ 1,000	$ 1,000
Change in fair value of convertible debt		$ 2,400	$ 2,386	$ 1,450

Warrants - Summary of Assumptio

Warrants - Summary of Assumptions Used to Record Fair Value of Warrants (Detail) - Warrants [Member]	Dec. 31, 2020
Risk-Free Interest Rate [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value input	1.90%
Expected Term [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value input (in years)	10 months 24 days
Expected Volatility [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value input	100.00%
Expected Dividend Yield [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value input	0.00%

Warrants - Summary of Warrant A

Warrants - Summary of Warrant Activity (Detail) - Common Stock Warrants [Member]	12 Months Ended
	Dec. 31, 2020shares
Class of Warrant or Right [Line Items]
Outstanding, Beginning Balance	481,781
Exercises	(337,397)
Outstanding, Ending balance	144,384

Warrants - Additional Informati

Warrants - Additional Information (Detail) - USD ($)	1 Months Ended		12 Months Ended
	Sep. 30, 2019	Nov. 30, 2016	Dec. 31, 2020
September 2019 Warrants [Member]
Class of Warrant or Right [Line Items]
Exercise price	$ 16.84
Warrants expiration date	Sep. 19, 2021
Warrants issued to purchase shares of common stock	3,750
Warrants outstanding	3,750
IPO [Member]
Class of Warrant or Right [Line Items]
Exercise price			$ 60
Warrants expiration date			May 5, 2021
Warrants issued to purchase shares of common stock			7,087
Warrants outstanding			7,087
Private Placement [Member]
Class of Warrant or Right [Line Items]
Issuance of common stock		411,184
Fair value of equity			$ 37,000
Exercise price		$ 43.16
Warrants expiration date	Nov. 23, 2021
Warrants issued to purchase shares of common stock		411,184
Shares Exercised During the period			340,137
Warrants outstanding			71,047
Common Stock Warrants [Member] | Pontifax [Member]
Class of Warrant or Right [Line Items]
Exercise price	$ 8.32
Warrants expiration date	Sep. 19, 2025
Warrants issued to purchase shares of common stock	62,500
Warrants outstanding	62,500

Stock Option Plans - Summary of

Stock Option Plans - Summary of Stock Option Valuation (Detail)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based Payment Arrangement [Abstract]
Risk free rate, Minimum	0.17%	1.74%
Risk free rate, Maximum	0.42%	1.85%
Expected volatility, Minimum	82.80%	70.03%
Expected volatility, Maximum	98.30%	70.31%
Expected dividend yield	0.00%	0.00%
Expected term (in years)	5 years 1 month 6 days	5 years 1 month 6 days

Stock Option Plans - Summary _2

Stock Option Plans - Summary of Option Activity (Detail) - Two Thousand And Nineteen Equity Incentive Plan [Member] - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Beginning Balance	259,148
Number of Shares, Granted	415,343
Number of Shares, Exercised	(42,260)
Number of Shares, Forfeited	(28,883)
Number of Shares, Ending balance	603,348	259,148
Number of Shares, Exercisable	89,957
Weighted average exercise price, Options outstanding, Beginning Balance	$ 7.07
Weighted average exercise price, Granted	0.20
Weighted average exercise price, Exercised	0.10
Weighted average exercise price, Forfeited	4.79
Weighted average exercise price, Options outstanding, Ending Balance	2.94	$ 7.07
Weighted average exercise price, Options exercisable	$ 9.24
Weighted average contractual term	9 years 3 months 18 days	9 years 2 months 26 days
Weighted average contractual term ,Exercisable	8 years 8 months 12 days
Intrinsic Value, Options outstanding	$ 8,494	$ 4,334
Intrinsic Value, Option exercisable	$ 1,228

Stock Option Plans - Summary _3

Stock Option Plans - Summary of Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 3,489	$ 2,669
2014 and 2015 Stock Incentive Plans [Member] | Stock Options [Member] | Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	684	554
2014 and 2015 Stock Incentive Plans [Member] | Stock Options [Member] | General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 2,805	$ 2,115

Stock Option Plans - Additional

Stock Option Plans - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	12 Months Ended		19 Months Ended
	Mar. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020
2019 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of authorized shares of common stock to be issued			2,327,736
Vesting period				4 years
Arrangement term				10 years
Number of shares remain available for grant		33,778		33,778
Unrecognized stock-based compensation expense		$ 5.1	$ 2.7	$ 5.1
Weighted-average remaining vesting period		3 years 2 months 12 days	2 years 10 months 24 days
2019 Equity Incentive Plan [Member] | Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage				28.00%
2014 and 2015 Stock Incentive Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of authorized shares of common stock to be issued	2,300,000
2015 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of authorized shares of common stock to be issued	1,666,863
Number of shares remain available for grant		678,949		678,949
Number of shares common stock reserved for issuance, increase	800,000
Weighted-average fair value of all stock options granted		$ 14.45	$ 23.94
Fair value of stock options vested		$ 2	$ 1.6
New Ordinary Shares [Member] | 2019 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of authorized shares of common stock to be issued			1,922,241
Replacement For Grants Under Previous Scheme [Member] | 2019 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of authorized shares of common stock to be issued			405,495

Significant agreements - Summar

Significant agreements - Summary of License and Collaboration Agreements (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Total collaboration revenues	$ 11,256	$ 28,321
Switzerland | Ares [Member]
Disaggregation of Revenue [Line Items]
Total collaboration revenues	9,930	25,871
US | Denali [Member]
Disaggregation of Revenue [Line Items]
Total collaboration revenues	$ 1,326	$ 2,450

Significant agreements - Summ_2

Significant agreements - Summary of Contract Assets and Liabilities (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Contract With Customer Asset And Liability [Line Items]
Balance at beginning of year	$ 442	$ 5,824
Additions	37	31
Acquired with Subsidiaries		869
Recognized	(184)	(6,376)
Impact of exchange rates	5	94
Balance at end of year	300	442
Ares [Member]
Contract With Customer Asset And Liability [Line Items]
Balance at beginning of year	33	5,824
Additions	37	0
Acquired with Subsidiaries		0
Recognized	(33)	(5,903)
Impact of exchange rates	0	112
Balance at end of year	37	33
Denali [Member]
Contract With Customer Asset And Liability [Line Items]
Balance at beginning of year	409	0
Additions	0	31
Acquired with Subsidiaries		869
Recognized	(151)	(473)
Impact of exchange rates	5	(18)
Balance at end of year	$ 263	$ 409

Significant agreements - Additi

Significant agreements - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended		7 Months Ended	8 Months Ended	12 Months Ended
	Aug. 31, 2020	May 31, 2018	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Mar. 26, 2021
Disaggregation of Revenue [Line Items]
Revenue from contract with customers revenue recognised under cost method					$ 11,256	$ 28,321
Denali Holding Limited [member] | License agreement [member]
Disaggregation of Revenue [Line Items]
Payment received pursuant to license agreement			$ 18,000
Business combination liabilities assumed			200
Denali Holding Limited [member] | License agreement [member] | Transferin F Cab Target One [member]
Disaggregation of Revenue [Line Items]
Upfront Fee Received		$ 5,500
Transaction price allocated					7,100
Increase in the transaction price						6,600
Denali Holding Limited [member] | License agreement [member] | Transferin F Cab Target One [member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Performance obligation revenue recognized					1,500	1,500
Denali Holding Limited [member] | License agreement [member] | Transferin F Cab Target One [member] | For Grant Of Intellecutal Property Rights [member]
Disaggregation of Revenue [Line Items]
Transaction price allocated					5,000
Denali Holding Limited [member] | License agreement [member] | Transferin F Cab Target One [member] | For Research And Development Services [member]
Disaggregation of Revenue [Line Items]
Transaction price allocated					2,100
Denali Holding Limited [member] | License agreement [member] | Transferin F Cab Target Two [member]
Disaggregation of Revenue [Line Items]
Upfront Fee Received	$ 6,000
Transaction price allocated					2,100
Denali Holding Limited [member] | License agreement [member] | Transferin F Cab Target Two [member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Performance obligation revenue recognized					1,300	900
Denali Holding Limited [member] | License agreement [member] | Transferin F Cab Target Two [member] | For Grant Of Intellecutal Property Rights [member]
Disaggregation of Revenue [Line Items]
Transaction price allocated					5,100
Denali Holding Limited [member] | License agreement [member] | Transferin F Cab Target Two [member] | For Research And Development Services [member]
Disaggregation of Revenue [Line Items]
Transaction price allocated					3,000
Ares Trading [member] | License And Collaboration Agreement [member] | Delta [member]
Disaggregation of Revenue [Line Items]
Option Payment Received				$ 11,100		14,000
Ares Trading [member] | License And Collaboration Agreement [member] | Development Milestone [member]
Disaggregation of Revenue [Line Items]
Milestone payment receivable				71,600		71,600
Ares Trading [member] | License And Collaboration Agreement [member] | Regulatory Milestone [member]
Disaggregation of Revenue [Line Items]
Milestone payment receivable				83,900		83,900
Ares Trading [member] | License And Collaboration Agreement [member] | Sales Based Milestone [member] | Delta [member]
Disaggregation of Revenue [Line Items]
Milestone payment receivable				168,000		168,000
Ares Trading [member] | License And Collaboration Agreement [member] | Phase Two Clinical Trial [member] | Development Milestone [member] | Delta [member]
Disaggregation of Revenue [Line Items]
Milestone payment receivable				48,700		48,700
Ares Trading [member] | License And Collaboration Agreement [member] | Phase Two Clinical Trial [member] | Regulatory Milestone [member] | Delta [member]
Disaggregation of Revenue [Line Items]
Milestone payment receivable				61,600		61,600
Ares Trading [member] | License And Collaboration Agreement [member] | Phase One Clinical Trial [member] | Delta [member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customers revenue recognised under cost method						13,300
Ares Trading [member] | Amended And Restated License And Collaboration Agreement [member] | Delta [member]
Disaggregation of Revenue [Line Items]
Transaction price allocated				$ 15,400		15,400
Ares Trading [member] | Amended And Restated License And Collaboration Agreement [member] | Phase Two Clinical Trial [member] | Delta [member]
Disaggregation of Revenue [Line Items]
Performance obligation revenue recognized					1,400
Revenue from contract with customers revenue recognised under cost method						1,400
Ares Trading [member] | Amended And Restated License And Collaboration Agreement [member] | Phase One Clinical Trial [member] | Delta [member]
Disaggregation of Revenue [Line Items]
Performance obligation revenue recognized					8,500
Revenue from contract with customers revenue recognised under cost method						$ 11,100
Ares Trading [member] | Amended And Restated License And Collaboration Agreement One [member] | Sales Based Milestone [member] | Delta [member]
Disaggregation of Revenue [Line Items]
Milestone payment receivable					309,500
Ares Trading [member] | Amended And Restated License And Collaboration Agreement One [member] | Development And Regulatory Milestone [member] | Delta [member]
Disaggregation of Revenue [Line Items]
Milestone payment receivable					$ 501,700
Ares Trading [member] | Amended And Restated License And Collaboration Agreement One [member] | Development And Regulatory Milestone [member] | Delta [member] | Subsequent Event [Member]
Disaggregation of Revenue [Line Items]
Option fee receivable							$ 3,100
F Star Gamma [member] | Denali Holding Limited [member] | License agreement [member]
Disaggregation of Revenue [Line Items]
Receivable in respect of license agreeement			4,000
Maximum [member] | F Star Gamma [member] | Denali Holding Limited [member] | License agreement [member]
Disaggregation of Revenue [Line Items]
Business combination contingent consideration asset			91,400
Maximum [member] | F Star Gamma And Shareholders [member] | Denali Holding Limited [member] | License agreement [member]
Disaggregation of Revenue [Line Items]
Business combination contingent consideration asset			$ 437,000

Income Taxes - Schedule of Inco

Income Taxes - Schedule of Income Before Income Tax Domestic and Foreign (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Schedule Of Income Before Income Tax [Line Items]
Net (loss)/profit before income taxes	$ (25,620)	$ (23,750)
United Kingdom
Schedule Of Income Before Income Tax [Line Items]
Net (loss)/profit before income taxes	(24,490)	(20,943)
Austria
Schedule Of Income Before Income Tax [Line Items]
Net (loss)/profit before income taxes	315	(62)
United States
Schedule Of Income Before Income Tax [Line Items]
Net (loss)/profit before income taxes	$ (1,445)	$ (2,745)

Income Taxes - Schedule of Comp

Income Taxes - Schedule of Components of Income Tax Expense Benefit (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Current Federal, State and Local, Tax Expense (Benefit) [Abstract]
Federal	$ (41)	$ (152)
State	0	(7)
Foreign	42	0
Total current income tax (provision) benefit	1	(159)
Total deferred income tax (benefit)	0	896
Total benefit from income taxes	$ 1	$ 737

Income Taxes - Schedule of Reco

Income Taxes - Schedule of Reconciliation of The Statutory Federal Tax Rate to The Company's Effective Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Income tax (provision) benefit at statutory rate	21.00%	19.00%
Expenses not deductible	(9.40%)	(8.50%)
Net losses surrendered for U.K. R&D tax credit	(4.60%)	(10.30%)
Change in valuation allowance	(7.10%)	3.80%
Foreign rate differential	(1.50%)	(0.10%)
Adjustment in respect to prior years	1.60%	(0.80%)
Actual income tax expense effective tax rate	0.00%	3.10%

Income Taxes - Schedule of Sign

Income Taxes - Schedule of Significant Components of the Company's Deferred Tax Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Components of Deferred Tax Assets and Liabilities [Abstract]
Net operating loss carryforwards	$ 45,053	$ 9,403
Research and development credit carryforwards	957	0
Capitalized Expenditures	5,238
Lease Obligation	860	0
Stock option expense	1,206	742
Other	18	0
Total gross deferred tax assets	53,332	10,145
Valuation Allowance	(49,304)	(7,607)
Net deferred tax assets	4,028	2,538
Deferred tax liabilities:
Acquired Intangibles	(3,763)	(2,205)
Right of Use Assets	(769)	0
Capital Allowances	(72)	(333)
Net deferred tax liability	$ (576)	$ 0

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) £ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)	Dec. 31, 2020GBP (£)	Dec. 31, 2019USD ($)
Income Taxes [Line Items]
Income tax (expense) benefit	$ (1,000)		$ (737,000)
Unrecognized tax benefits	0		0
Interest and penalties on unrecognized tax benefits recognized during the period	0		0
Accrued interest and penalties on unrecognized tax benefits	0		0
Deferred tax assets valuation allowance	49,304,000		7,607,000
Primarily due acquisition			$ 7,500,000
Deferred tax assets increase decrease in valuation allowance	41,700,000
Tax Year 2030 | Domestic Tax Authority [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	125,800,000
Tax Year 2030 | Foreign Tax Authority [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	48,900,000
Tax Year 2030 | State [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	126,500,000
Tax Year 2031 | Domestic Tax Authority [Member]
Income Taxes [Line Items]
Research and development tax credit carryforwards	300,000
Tax Year 2031 | State [Member]
Income Taxes [Line Items]
Research and development tax credit carryforwards	$ 800,000
United Kingdom
Income Taxes [Line Items]
Minimum amount of loss incurred eligible for carryforward | £		£ 5
Losses as a percentage of incremental taxable profits that can be carried forward	50.00%	50.00%
Corporate Tax			19.00%
Austria
Income Taxes [Line Items]
Losses as a percentage of taxable profits that can be carried forward	75.00%	75.00%

Net Loss Per Share - Summary of

Net Loss Per Share - Summary of Computation of Basic and Diluted Net Loss Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Earnings Per Share, Basic and Diluted [Abstract]
Net loss	$ (25,619)	$ (23,013)
Weighted average number shares outstanding, basic and diluted	2,643,175	1,545,177
Net loss income per common, basic and diluted	$ (9.69)	$ (14.89)

Net Loss Per Share - Additional

Net Loss Per Share - Additional Information (Detail) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from the computation of earnings per share		205,874
Stock Options [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from the computation of earnings per share	102,093
Potential Stock Options [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from the computation of earnings per share	501,255

Commitments and Contingencies -

Commitments and Contingencies - Summary of Maturities of Operating Lease Liabilities (Detail) $ in Thousands	Dec. 31, 2020USD ($)
Commitments and Contingencies Disclosure [Abstract]
2021	$ 542
2022	451
2023	462
2024	474
2025	486
Thereafter	1,444
Total lease payments	$ 3,859

Commitments and Contingencies_2

Commitments and Contingencies - Summary of Future Expected Cash Receipts From Subleases (Detail) $ in Thousands	Dec. 31, 2020USD ($)
Commitments and Contingencies Disclosure [Abstract]
2021	$ 83
2022	462
2023	474
2024	486
2025	498
Thereafter	1,482
Total sublease receipts	$ 3,485

Commitments and Contingencies_3

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Operating Lease, existence of option to extend	true
Operating leases, weighted average discount rate	5.00%	8.00%
Operating lease costs	$ 0.3	$ 0.4
Contractual Obligation	$ 4.7	$ 1
Maximum [member]
Sublease term	7 years 7 months 6 days
Minimum [member]
Sublease term	4 months 24 days
Principal Office And Laboratory Space [Member]
Operating leases, weighted average remaining lease term	7 years 9 months 18 days
Operating leases, extendable lease term	5 years
Operating leases, option to extend lease	an option to extend the lease for up to 5 years
Former Headquarters [Member]
Operating leases, weighted average remaining lease term	6 months

Employee Plans - Additional Inf

Employee Plans - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based Payment Arrangement, Disclosure [Abstract]
Employer Discretionary Contribution Amount	$ 0.6	$ 0.6

Related Party Transactions 20_3

Related Party Transactions 2019 Reorganization - Summary of Related Party Transactions (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Beta [Member] | R&D recharges [Member]
Related Party Transaction [Line Items]
Expenses	$ 2,126
Beta [Member] | Other recharges [Member]
Related Party Transaction [Line Items]
Expenses	552
F-star Biotechnology Limited [Member] | R&D recharges [Member]
Related Party Transaction [Line Items]
Expenses	235
F-star Biotechnology Limited [Member] | Other recharges [Member]
Related Party Transaction [Line Items]
Expenses	0
GmbH [Member] | R&D recharges [Member]
Related Party Transaction [Line Items]
Expenses	0
GmbH [Member] | Other recharges [Member]
Related Party Transaction [Line Items]
Expenses	$ 13

Related Party Transactions 20_4

Related Party Transactions 2019 Reorganization - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Avacta Life Sciences Limited [Member]
Purchases from Related Party	$ 0	$ 0.2
Outstanding Amount	$ 0	0.1
Triplet Therapeutics [Member] | Office rental and related office costs [Member]
Other Income		$ 0.1

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) $ in Millions	Mar. 26, 2021USD ($)
Subsequent Event [Member] | Amended And Restated License And Collaboration Agreement One [Member] | Development And Regulatory Milestone [Member] | Delta [Member] | Ares Trading [Member]
Subsequent Event [Line Items]
Option fee receivable	$ 3.1