F-star Therapeutics (FSTX) 10-Q 10 Nov 21 2021 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2021	Nov. 08, 2021
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Trading Symbol	FSTX
Title of 12(b) Security	Common Stock, $0.0001 par value per
Security Exchange Name	NASDAQ
Entity Registrant Name	F-star Therapeutics, Inc.
Entity Central Index Key	0001566373
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Shell Company	false
Document Quarterly 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	Eddeva 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 Common Stock, Shares Outstanding		20,624,494

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 71,050	$ 18,526
Other receivables	436	0
Prepaid expenses and other current assets	3,173	3,976
Tax incentive receivable	1,502	3,563
Total current assets	76,161	26,065
Property and equipment, net	1,011	789
Right of use asset	3,501	2,782
Goodwill	14,885	14,926
In-process research and development and intangible assets, net	18,790	18,986
Other long-term assets	450	61
Total assets	114,798	63,609
Current liabilities:
Accounts payable	1,569	4,597
Accrued expenses and other current liabilities	5,642	9,461
Contingent value rights	648	2,080
Lease obligations, current	976	539
Deferred revenue	0	300
Total current liabilities	8,835	16,977
Long term Liabilities:
Term debt	9,535	0
Lease obligations	2,875	2,622
Contingent value rights	2,899	440
Deferred tax liability	576	576
Total liabilities	24,720	20,615
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.0001 par value; authorized, 10,000,000 shares at September 30, 2021 and December 31, 2020; no shares issued or outstanding at September 30, 2021 and December 31, 2020	0	0
Common Stock, $0.0001 par value; authorized 200,000,000 shares at September 30, 2021 and December 31, 2020; 20,623,041 and 9,100,117 shares issued and outstanding at September 30, 2021 and December 31, 2020	2	1
Additional paid-in capital	174,410	91,238
Accumulated other comprehensive loss	(1,142)	(1,077)
Accumulated deficit	(83,192)	(47,168)
Total stockholders' equity	90,078	42,994
Total liabilities and stockholders' equity	$ 114,798	$ 63,609

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2021	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	20,623,041	9,100,117
Common stock, shares outstanding	20,623,041	9,100,117

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
License revenue	$ 751	$ 9,195	$ 3,668	$ 11,093
Operating expenses:
Research and development	5,113	5,321	20,536	10,695
General and administrative	5,239	7,261	18,169	13,805
Total operating expenses	10,352	12,582	38,705	24,500
Loss from operations	(9,601)	(3,387)	(35,037)	(13,407)
Other non-operating (expense) income:
Other income (expense)	(746)	506	230	(1,164)
Change in fair-value of convertible debt	0	(446)	0	(2,330)
Change in fair value of contingent value rights	(444)	0	(1,027)	0
Loss before income taxes	(10,791)	(3,327)	(35,834)	(16,901)
Income tax expense	0	(124)	(190)	(171)
Net loss	(10,791)	(3,451)	(36,024)	(17,072)
Net loss attributable to common stockholders	$ (10,791)	$ (3,451)	$ (36,024)	$ (17,072)
Basic and diluted adjusted net loss per common shares	$ (0.52)	$ (1.88)	$ (2.35)	$ (9.34)
Weighted-average number of shares outstanding, basic and diluted	20,617,822	1,832,194	15,300,433	1,828,597
Other comprehensive (loss) gain:
Net loss	$ (10,791)	$ (3,451)	$ (36,024)	$ (17,072)
Foreign currency translation	117	14	(65)	424
Total comprehensive loss	$ (10,674)	$ (3,437)	$ (36,089)	$ (16,648)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	As Originally Stated [Member]	Adjustment [Member]	Common Shares	Common SharesAs Originally Stated [Member]	Capital in Excess of par Value	Capital in Excess of par ValueAs Originally Stated [Member]	Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive LossAs Originally Stated [Member]	Accumulated Other Comprehensive LossAdjustment [Member]	Accumulated deficit	Accumulated deficitAs Originally Stated [Member]	Accumulated deficitAdjustment [Member]	Seed Preferred Shares [member]Preferred Stock	Series A Preferred Stock [member]Preferred Stock
Balance at Dec. 31, 2019	$ 8,536			$ 1		$ 31,718		$ (1,634)			$ (21,549)
Balance, shares at Dec. 31, 2019				4,128,441										103,611	1,441,418
Issuance of common stock for services rendered, shares				10,972
Issuance of common stock in connection with at-the-market offering, net of issuance costs, shares				172,724
Equity adjustment from foreign currency translation	424							424
Share-based compensation	2,199					2,199
Net loss	(17,072)										(17,072)
Balance at Sep. 30, 2020	(5,913)			$ 1		33,917		(1,210)			(38,621)
Balance, shares at Sep. 30, 2020				4,312,137										103,611	1,441,418
Balance at Jun. 30, 2020	(3,670)			$ 1		32,723		(1,224)			(35,170)
Balance, shares at Jun. 30, 2020				4,312,137										103,611	1,441,418
Equity adjustment from foreign currency translation	14							14
Share-based compensation	1,194					1,194
Net loss	(3,451)										(3,451)
Balance at Sep. 30, 2020	(5,913)			$ 1		33,917		(1,210)			(38,621)
Balance, shares at Sep. 30, 2020				4,312,137										103,611	1,441,418
Balance at Dec. 31, 2020	42,994			$ 1		91,238		(1,077)			(47,168)
Balance, shares at Dec. 31, 2020				9,100,117
Issuance of warrants in connection with term loan	326					326
Issuance of common stock in connection with at-the-market offering, net of issuance costs	9,115					9,115
Issuance of common stock in connection with at-the-market offering, net of issuance costs, shares				979,843
Issuance of common stock in connection with public offering, net of issuance costs , share				10,439,347
Issuance of common stock in connection with public offering, net of issuance costs	68,178			$ 1		68,177
Equity adjustment from foreign currency translation	(65)							(65)
RSU vesting and stock option exercises, Shares				103,734
Share-based compensation	5,554					5,554
Net loss	(36,024)										(36,024)
Balance at Sep. 30, 2021	90,078			$ 2		174,410		(1,142)			(83,192)
Balance, shares at Sep. 30, 2021				20,623,041
Balance at Jun. 30, 2021	99,237	$ 98,993	$ 244	$ 2	$ 2	172,895	$ 172,895	(1,259)	$ (1,218)	$ (41)	(72,401)	$ (72,686)	$ 285
Balance, shares at Jun. 30, 2021				20,586,562	20,586,562
Equity adjustment from foreign currency translation	117							117
RSU vesting and stock option exercises, Shares				36,479
Share-based compensation	1,515					1,515
Net loss	(10,791)										(10,791)
Balance at Sep. 30, 2021	$ 90,078			$ 2		$ 174,410		$ (1,142)			$ (83,192)
Balance, shares at Sep. 30, 2021				20,623,041

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities:
Net loss	$ (36,024)	$ (17,072)
Adjustments to reconcile net loss to net cash used in operating activities:
Share based compensation expense	5,554	2,199
Foreign currency (gain) loss	(66)	968
(Gain) loss on disposal of property, plant and equipment	(9)	7
Depreciation	435	887
Amortization of intangible assets	65	0
Non-cash interest	42	815
Interest expense	69	0
Fair value adjustments	1,027	2,330
Operating right of use amortization	749	0
Changes in operating assets and liabilities:
Other receivables	(444)	0
Prepaid expenses and other current assets	800	1,254
Tax incentive receivable	2,083	8,403
Accounts payable	(3,050)	677
Accrued expenses and other current liabilities	(3,796)	233
Deferred revenue	(305)	(352)
Operating lease liability	(400)	(467)
Other long-term asset	(778)	0
Net cash used in operating activities	(34,048)	(118)
Cash flows from investing activities:
Purchase of property, plant and equipment	(658)	0
Proceeds from sale of property, plant and equipment	15	0
Purchase of intangible assets	0	(50)
Net cash used in investing activities	(643)	(50)
Cash flows from financing activities:
Proceeds from issuance of convertible notes	0	850
Net proceeds from issuance of common stock	77,295	0
Net proceeds from term debt	9,845	0
Payment of debt issuance costs	(92)	0
Net cash provided by financing activities	87,048	850
Net increase in cash and cash equivalents	52,357	682
Effect of exchange rate changes on cash	167	(56)
Cash and cash equivalents at beginning of period	18,526	4,901
Cash and cash equivalents at end of period	71,050	5,527
Supplemental disclosure of cash flow information
Cash paid for income taxes	36	42
Cash paid for interest	296	0
Non-cash investing and financing activities:
Additions to ROU assets obtained from new operating lease liabilities	1,468	0
Issuance of warrants	$ 326	$ 0

Nature of Business and Summary

Nature of Business and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Nature of Business and Summary of Significant Accounting Policies	1. Nature of Business and Summary of Significant Accounting Policies Nature of Business F-star Therapeutics, Inc. (collectively with its subsidiaries, “F-star” or the “Company”) is a clinical-stage biopharmaceutical company dedicated to developing next generation immunotherapies to transform the lives of patients with cancer. F-star is pioneering the use of tetravalent (2+2) bispecific antibodies to create a paradigm shift in cancer therapy. The Company has four second-generation immuno-oncology ("IO") therapeutics in the clinic, each directed against some of the most promising IO targets in drug development, including LAG-3 and CD137. F-star’s proprietary antibody discovery platform is protected by a vast intellectual property portfolio, with 500 granted and pending patent applications relating to its platform technology and associated product pipeline. The Company has attracted multiple partnerships with biopharma targeting the significant unmet needs across several disease areas, including oncology, immunology, and CNS. F-star’s goal is to offer patients better and more durable benefits than currently available immuno-oncology treatments by developing medicines that seek to block tumor immune evasion. Through its proprietary tetravalent, bispecific natural antibody (mAb² ™ ) format, F-star’s mission is to generate highly differentiated medicines with monoclonal antibody-like manufacturability, good safety and tolerability. With four distinct binding sites in a natural human antibody format, F-star believes its proprietary technology will overcome many of the challenges facing current immuno-oncology therapies, due to the strong pharmacology enabled by tetravalent bispecific binding. Share Exchange Agreement On November 20, 2020, F-star Therapeutics, Inc., formerly known as Spring Bank Pharmaceuticals, Inc., completed a business combination (the “Transaction”) with F-star Therapeutics Limited (“F-star Ltd”) in accordance with the terms of the Share Exchange Agreement, dated July 29, 2020 (the “Exchange Agreement”), by and among the Company, F-star Ltd and certain holders of capital stock and convertible notes of F-star Ltd (each a “Seller”, and collectively with holders of F-star Ltd securities who subsequently became parties to the Exchange Agreement, the “Sellers”). Pursuant to the Exchange Agreement, each ordinary share of F-star Ltd outstanding immediately prior to the closing of the Transaction (the “Closing”) was exchanged by the Sellers that owned such F-star Ltd shares for a number of duly authorized, validly issued, fully paid and non-assessable shares of Company common stock pursuant to the exchange ratio formula set forth in the Exchange Agreement (the “Exchange Ratio”), rounded to the nearest whole share of Company common stock (after aggregating all fractional shares of Company common stock issuable to such Seller). Also, on November 20, 2020, in connection with, and prior to completion of, the Transaction, Spring Bank effected a 1-for-4 reverse stock split of its common stock (the “Reverse Stock Split”) and, following the completion of the Transaction, changed its name to F-star Therapeutics, Inc. Following the completion of the Transaction, the business of the Company became the business conducted by F-star, which is a clinical-stage immuno-oncology company focused on cancer treatment through its proprietary tetravalent bispecific antibody programs. Unless otherwise noted, all references to share amounts in this report reflect the Reverse Stock Split. Liquidity On March 30, 2021, the Company entered into a Sales Agreement (the “Sales Agreement”) with SVB Leerink LLC (“SVB Leerink”) with respect to an “at-the-market” offering as defined in Rule 415 of the Securities Act of 1933, as amended, under which the Company could offer and sell, from time to time in its sole discretion, shares of its common stock, par value $ 0.0001 per share, having an aggregate offering price of up to $ 50.0 million through SVB Leerink as its sales agent. As of May 6, 2021, the Company had issued and sold 979,843 shares of common stock for gross proceeds of $ 9.5 million, resulting in net proceeds of $ 9.1 million after deducting sales commissions and offering expenses. On May 6, 2021, the Company terminated the Sales Agreement. On August 13, 2021, the Company entered into a Sales Agreement (the “2021 Sales Agreement”) with SVB Leerink with respect to an at-the-market offering program under which the Company may offer and sell, from time to time at its sole discretion, shares of its common stock, having an aggregate offering price of up to $ 50.0 million through SVB Leerink as its sales agent. As of September 30, 2021 Company had no t offered or sold any common stock under the 2021 Sales Agreement. On May 6, 2021, the Company entered into an underwriting agreement with SVB Leerink, as representative of the underwriters, relating to an underwritten public offering (the “Underwritten Public Offering”) of 10.4 million shares of the Company’s common stock, par value $ 0.0001 per share. The underwritten public offering resulted in gross proceeds of $ 73.1 million. The Company incurred $ 4.4 million in issuance costs and $ 0.5 million of professional fees associated with the underwritten public offering, resulting in net proceeds to the Company of $ 68.2 million. On April 1, 2021, the Company, as borrower, entered into a Venture Loan and Security Agreement (the “Loan and Security Agreement”) with Horizon Technology Finance Corporation (“Horizon”), as lender and collateral agent for itself. The Loan and Security Agreement provides for four separate and independent $ 2.5 million term loans (“Loan A”, “Loan B”, “Loan C”, and “Loan D”) (with each of Loan A, Loan B, Loan C and Loan D, individually a “Term Loan” and, collectively, the “Term Loans”), whereby, upon the satisfaction of all the conditions to the funding of the Term Loans, each Term Loan will be delivered by Horizon to the Company in the following manner: (i) Loan A was delivered by Horizon to the Company by April 1, 2021, (ii) Loan B was delivered by Horizon to the Company by April 1, 2021, (iii) Loan C was delivered by Horizon to the Company by June 30, 2021, and (iv) Loan D was delivered by Horizon to the Company by June 30, 2021. The Company may only use the proceeds of the Term Loans for working capital or general corporate purposes as contemplated by the Loan and Security Agreement. On April 1, 2021, the Company drew down $ 5 million. On June 22, 2021, the Company drew down another $ 5 million under this facility. The Company has incurred significant losses and has an accumulated deficit of $ 83.2 million as of September 30, 2021 . F-star expects to incur substantial losses in the foreseeable future as it conducts and expands its research and development activities and clinical trial activities. As of September 30, 2021, the Company had cash of $ 71.1 million and working capital of $ 67.3 million . As of November 10, 2021, the date of issuance of the condensed consolidated financial statements, the Company’s cash and cash equivalents on hand will be sufficient to fund its current operating plan and planned capital expenditures for at least the next 12 months. The Company may continue 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 future 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. Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles (“U.S. GAAP”) and the rules and regulations of the Securities Exchange Commission ("SEC") for interim financial statements. The accompanying interim condensed consolidated financial statements as of September 30, 2021, and for the three and nine months ended September 30, 2021 and 2020, and information contained within the notes to these condensed consolidated financial statements, are unaudited. These unaudited interim condensed consolidated financial statements have been prepared on the same basis as the Company’s audited annual financial statements and in management's opinion contain all adjustrevisionments (including normal recurring adjustments) necessary for the fair presentation of the Company’s financial position as of September 30, 2021, results of operations for the three and nine months ended September 30, 2021 and 2020, statement of stockholders’ equity for the three and nine months ended September 30, 2021 and 2020 and its cash flows for the nine months ended September 30, 2021 and 2020. These interim condensed consolidated financial statements should be read in conjunction with the Company’s annual audited financial statements and notes thereto included in the Company’s Annual Report filed on SEC Form 10-K for the year ended December 31, 2020. The results for the three and nine months ended September 30, 2021, are not necessarily indicative of the results expected for the full fiscal year or any interim period. Revision of Previously Issued Financial Statements In September 2021, the Company identified an error in its accounting treatment for research and development expenses. This error resulted in an overstatement of research and development expenses for the first six months of 2021 and accrued expenses and other current liabilities as of March 31, 2021 and June 30, 2021. The Company assessed the materiality of this error on prior period financial statements in accordance with the SEC Staff Accounting Bulletin Number 99, Materiality, and ASC 250-10, Accounting Changes and Error Corrections. The Company determined that this error was not material to the financial statements of any prior interim period. To correct the immaterial misstatement, the Company decreased accumulated deficit by $ 0.3 million as of June 30, 2021. Principles of Consolidation The Company’s interim condensed consolidated financial statements have been prepared in conformity with U.S. GAAP. Any reference in these notes to applicable guidance is meant to refer to the authoritative U.S. GAAP as found in the ASC and Accounting Standards Updates (“ASU”) of the FASB. The accompanying condensed consolidated financial statements include the accounts of F-star Therapeutics, Inc. and its wholly owned subsidiaries. All inter-company balances and transactions between the consolidated companies have been eliminated in consolidation. Use of Estimates The preparation of the condensed consolidated financial statements in conformity with U.S. 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 condensed consolidated financial statements and the reported amounts of expenses during the reporting years. Significant estimates and assumptions reflected in these condensed 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 Ltd fair value of the convertible loan containing embedded derivatives, the fair value of contingent value rights, the accrual for research and development expenses, revenue recognition, fair values of acquired intangible assets and impairment review of those assets, warrants, share based compensation expense, and income taxes. The Company bases its estimates on historical experience, known trends and other market-specific or other relevant factors that it believes to be reasonable under the circumstances. Estimates are periodically reviewed in light of reasonable changes in circumstances, facts and experience. Changes in estimates are recorded in the period in which they become known. Actual results could differ from those estimates or assumptions. 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 contract research organizations to provide its clinical trials and 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. 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 Leases The Company determines if an arrangement is a lease at inception. Operating leases are included in right-of-use (“ROU”) assets, and lease obligations in the Company’s consolidated balance sheets. ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent its obligation to make lease payments arising from the lease. Operating 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 an incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. This is the rate the Company would have to pay if borrowing on a collateralized basis over a similar term to each lease. The operating lease ROU asset also includes any lease payments made and excludes 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. Lease expense for lease payments is recognized on a straight-line basis over the lease term. Impairment of Long-Lived Assets Long-lived assets to be held and used are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable. When such events occur, the Company compares the carrying amounts of the assets to their undiscounted expected future cash flows. If the undiscounted cash flows are insufficient to recover the carrying value, an impairment loss is recorded for the difference between the carrying value and fair value of the asset. As of September 30, 2021 , no such impairment has been recorded. 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 bispecific antibody platform, (ii) performing research and development services to optimize drug candidates, and (iii) the grant of options to obtain additional research and development services or licenses for additional targets, or to optimize product candidates, upon the payment of option fees. The terms of these arrangements typically include payment to the Company of one or more of the following: non-refundable, upfront license fees; payments for research and development services; fees upon the exercise of options to obtain additional services or licenses; payments based upon the achievement of defined collaboration objectives; future regulatory and sales-based milestone payments; and royalties on net sales of future products. The Company has adopted FASB 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. (“Denali”), Ares Trading S.A. (“Ares,”) an affiliate of Merck KGaA, Darmstadt, Germany) and in July 2021 with AstraZeneca AB ("AstraZeneca"), which were determined to be within the scope of ASC 606. 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 compensation expense, 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 to 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. Warrants The Company accounts for warrants within stockholders equity or as liabilities based on the characteristics and provisions of each instrument. The Company evaluates outstanding warrants in accordance with ASC 480, Distinguishing Liabilities from Equity , and ASC 815, Derivatives and Hedging . If none of the criteria in the evaluation in these standards are met, the warrants are classified as a component of stockholders’ equity and initially recorded at their grant date fair value without subsequent remeasurement. Warrants that meet the criteria are classified as liabilities and remeasured to their fair value at the end of each reporting period. Stock-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. Fair value measurements of financial instruments The Company’s financial instruments consist of cash, accounts payable, CVRs 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 CVRs and the liability classified warrants are remeasured to fair value each reporting period. Net loss per share The Company computes net loss 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 considered participating securities and are included in the calculation of basic and diluted net (loss) income per share using the two-class method. In periods where the Company reports net losses, such losses are not allocated to the convertible preferred shares for the computation of basic or diluted net (loss) income. 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. 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. The potential recovery of deferred tax assets is evaluated by estimating the potential for future taxable profits, if any. Research and development tax credit As the entities located in the United Kingdom carry out extensive research and development activities, they seek to benefit from the UK research and development tax credit cash rebate regime known as the Small and Medium-sized Enterprises R&D Tax Credit Program (the “SME Program”). Qualifying expenditures largely comprise employment costs for research staff, consumables expenses incurred under agreements with third parties that conduct research and development, preclinical activities, clinical activities and manufacturing on the Company’s behalf and certain internal overhead costs incurred as part of research projects. The tax credit received in the United Kingdom pursuant to the SME Program permits companies to deduct an extra 130 % of their qualifying costs from their yearly profit or loss, as well as the normal 100 % deduction, to make a total 230 % deduction. If the company is incurring losses, it is entitled to claim a tax credit worth up to 14.5 % of the surrenderable loss. To qualify for relief under the SME Program, companies are required to employ fewer than 500 staff and have a turnover of under €100.0 million or a balance sheet total of less than €86.0 million. Research and development tax credits received in the United Kingdom are recorded as a reduction in research and development expenses. The UK research and development tax credit is payable to companies after surrendering tax losses and is not dependent on current or future taxable income. As a result, it is not reflected as part of the income tax provision. During the nine months ended September 30, 2021 the Company received $ 3.4 million in research and development tax credits related to the year ended December 31, 2020 . Contingencies Liabilities for loss contingencies arising from claims, assessments, litigation, fines, penalties, and other sources are reco rded 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. Recently Issued Accounting Pronouncements In June 2016, the FASB issued ASU No. 2016-13, Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”). ASU 2016-13 will change how companies account for credit losses for most financial assets and certain other instruments. For trade receivables, loans and held-to-maturity debt securities, companies will be required to recognize an allowance for credit losses rather than reducing the carrying value of the asset. In November 2019, the FASB issued ASU No. 2019-10, Financial Instruments — Credit Losses (Topic 326), Derivatives and Hedging (Topic 815), and Leases (Topic 842): Effective Dates to amend the effective date of ASU 2016-13, for entities eligible to be “smaller reporting companies,” as defined by the SEC, to be effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. Early adoption is permitted. The Company has not elected to early adopt ASU No. 2016-13. The Company is currently evaluating the potential impact that the adoption of ASU 2016-13 will have on the Company’s financial position and results of operations.

Business Combination

Business Combination	9 Months Ended
	Sep. 30, 2021
Business Combinations [Abstract]
Business Combination	2. Business Combination As described in Note 1, on November 20, 2020, F-star Ltd completed a 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 $ 21.5 million, which was determined based on the number of shares of common stock issued in connection with the Transaction, and (ii) the portion of the fair value attributable to in-the-money fully and partially vested stock options and warrants. The purchase price is allocated to the fair value of assets and liabilities acquired as follows in the table below (in thousands, except shares of common stock and fair value per share): Purchase Price Allocation 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 ( 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

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Net Loss Per Share	3. Net Loss Per Share The following table presents the calculation of basic and diluted net loss per share applicable to common stockholders of the Company (in thousands, except share and per share data): Net Loss Per Share For the Three Months For the Nine Months 2021 2020 2021 2020 Net loss $ ( 10,791 ) $ ( 3,451 ) $ ( 36,024 ) $ ( 17,072 ) Weighted average number shares 20,617,822 1,832,194 15,300,433 1,828,597 Net loss income per common, basic $ ( 0.52 ) $ ( 1.88 ) $ ( 2.35 ) $ ( 9.34 ) Diluted net loss per share of common stock is the same as basic net loss per share of common stock for all periods presented. The following shares were excluded from the calculation of diluted net loss per share, prior to the use of the treasury stock method or if-converted method, because their effect would have been anti-dilutive for the period presented: Potential Dilutive Shares For the Three and Nine Months 2021 2020 Convertible debt shares — 185,732 Common stock warrants 124,729 481,781 Stock options and RSUs 528,871 1,660,906

In Process R&D and Intangible A

In Process R&D and Intangible Assets, Net	9 Months Ended
	Sep. 30, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
In Process R&D and Intangible Assets, Net	4. In process R&D and intangible assets, net September 30, 2021 December 31, 2020 In-process R&D Intangible assets Total In-process R&D Intangible assets Total Cost $ 18,912 $ 4,469 $ 23,381 $ 23,554 $ — $ 23,554 Less: accumulated amortization — 65 65 — — — Less: impairments 4,526 — 4,526 4,568 — 4,568 $ 14,386 $ 4,404 $ 18,790 $ 18,986 $ — $ 18,986 During the three months ended September 30, 2021, $ 4.5 million of in-process R&D assets were reclassified to intangible assets as management determined that these assets had been brought into use and were no longer in-process. The appropriate useful life of the intangible assets was determined in accordance with ASC 350, Goodwill and Other. Accordingly, the useful lives are based on the period during which 95 % of the undiscounted cash flows of the assets will be realized. As a result $ 0.1 million of amortization was recorded for the three months ended September 30, 2021.

Property, Plant and Equipment,

Property, Plant and Equipment, net	9 Months Ended
	Sep. 30, 2021
Property, Plant and Equipment [Abstract]
Property, plant and equipment, net	5. Property, Plant and Equipment, net Property, plant and equipment, net consisted of the following (in thousands): Property, Plant and Equipment, net September 30, December 31, 2021 2020 Leasehold improvements $ 203 $ 15 Laboratory equipment 2,211 1,788 Furniture and office equipment 161 169 2,575 1,972 Less: Accumulated depreciation 1,564 1,183 $ 1,011 $ 789 Depreciation expense for the nine months ended September 30, 2021 and 2020 was $ 0.4 million and $ 0.9 million , respectively.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	6. 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 September 30, 2021 Using: Level 1 Level 2 Level 3 Total Liabilities: Contingent value rights $ — $ — $ 3,547 $ 3,547 Warrants — — 11 11 $ — $ — $ 3,558 $ 3,558 Fair Value Measurements as of December 31, 2020 Using: Level 1 Level 2 Level 3 Total Liabilities: Contingent value rights $ — $ — $ 2,520 $ 2,520 Warrants — — 37 37 $ — $ — $ 2,557 $ 2,557 The following table reflects the change in the Company’s Level 3 liabilities, which consists of warrants, for the nine months ended September 30, 2021 (in thousands): Change in Level 3 Liabilities November 2016 Private Contingent Value Balance at December 31, 2020 $ 37 $ 2,520 Warrants exercised ( 26 ) — Change in fair value of CVR — 1,027 Balance at September 30, 2021 $ 11 $ 3,547

Accrued Expenses and other Curr

Accrued Expenses and other Current Liabilities	9 Months Ended
	Sep. 30, 2021
Payables and Accruals [Abstract]
Accrued Expenses and other Current Liabilities	7. Accrued Expenses and other Current Liabilities Accrued expenses as of September 30, 2021 and December 31, 2020, consisted of the following (in thousands): September 30, December 31, 2021 2020 Clinical Trial Costs $ 2,764 $ 3,394 Severance 6 1,953 Compensation and Benefits 1,440 1,361 Professional Fees 735 1,593 Other 697 1,160 $ 5,642 $ 9,461

Term Debt

Term Debt	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Term Debt	8. Term Debt On April 1, 2021, the Company, as borrower, entered into the Loan and Security Agreement with Horizon, as lender and collateral agent for itself. The Loan and Security Agreement provides for four separate and independent $ 2.5 million term loans (Loan A, Loan B, Loan C, and Loan D), whereby, upon the satisfaction of all the conditions to the funding of the Term Loans, each Term Loan will be delivered by Horizon to the Company in the following manner: (i) Loan A was delivered by Horizon to the Company by April 1, 2021, (ii) Loan B was delivered by Horizon to the Company by April 1, 2021, (iii) Loan C was delivered by Horizon to the Company by June 30, 2021, and (iv) Loan D was delivered by Horizon to the Company by June 30, 2021. The Company may only use the proceeds of the Term Loans for working capital or general corporate purposes as contemplated by the Loan and Security Agreement. On April 1, 2021, the Company drew down $ 5 million. On June 22, 2021, the Company drew down another $ 5 million under this facility. The Company incurred $ 0.3 million of debt issuance costs and issued $ 0.3 million of warrants. The term note matures on the 48 -month anniversary following the funding date, therefore $ 5 million plus an additional fee of $ 0.2 million becomes due on April 1, 2025, and $ 5 million plus an additional fee of $ 0.2 million will become due on June 22, 2025. The principal balance the Term Loan bears a floating interest. The interest rate is calculated initially and, thereafter, each calendar month as the sum of (a) the per annum rate of interest from time to time published in The Wall Street Journal as contemplated by the Loan and Security Agreement, or any successor publication thereto, as the “prime rate” then in effect, plus (b) 6.25 %; provided that, in the event such rate of interest is less than 3.25 %, such rate shall be deemed to be 3.25 % for purposes of calculating the interest rate. Interest is payable on a monthly basis based on each Term Loan principal amount outstanding the preceding month and at September 30, 2021 the rate applied was 9.5 %. The Company may, at its option upon at least five business days’ written notice to Horizon, prepay all or any portion of the outstanding Term Loan by simultaneously paying to Horizon an amount equal to (i) any accrued and unpaid interest on the outstanding principal balance of the Term Loan so prepaid; plus (ii) an amount equal to (A) if such Term Loan is prepaid on or before the Loan Amortization Date (as defined in the Loan and Security Agreement) applicable to such Term Loan, three percent of the then outstanding principal balance of such Term Loan, (B) if such Term Loan is prepaid after the Loan Amortization Date applicable to such Term Loan, but on or before the date that is 12 months after such Loan Amortization Date, two percent of the then outstanding principal balance of such Term Loan, or (C) if such Term Loan is prepaid more than 12) months after the Loan Amortization Date applicable to such Term Loan, one percent of the then outstanding principal balance of such Term Loan; plus (iii) the outstanding principal balance of such Term Loan; plus (iv) all other sums, if any, that had become due and payable under the Loan and Security Agreement. The Company’s debt obligation consisted of the following (in thousands) Term Debt September 30, December 31, Term Loan A and B due April 2025 $ 5,000 $ — Term Loan C and D due June 2025 5,000 — Term debt 10,000 — Less: Unamortized deferred issuance costs ( 216 ) — Less: Warrant discount and interest ( 249 ) — Total debt obligations- long term $ 9,535 $ —

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2021
Equity [Abstract]
Stockholders' Equity	9. Stockholders’ Equity Common Stock On March 30, 2021, the Company entered into a Sales Agreement with SVB Leerink with respect to an "at-the-market” (“ATM”) offering program under which the Company could offer and sell, from time to time at its sole discretion, shares of its common stock, par value $ 0.0001 per share, having an aggregate offering price of up to $ 50.0 million (the “Placement Shares”) through SVB Leerink as its sales agent. Upon delivery of a placement notice in April 2021, and subject to the terms and conditions of the Sales Agreement, SVB Leerink began to sell the Placement Shares. Under the Sales Agreement, the Company agreed to pay SVB Leerink a commission equal to three percent of the gross sales proceeds of any Placement Shares, and also provided SVB Leerink with customary indemnification and contribution rights. For the three months ended June 30, 2021, the Company issued and sold 979,843 shares, for gross proceeds of $ 9.5 million, resulting in net proceeds of $ 9.2 million after deducting sales commissions. On May 6, 2021, the Company terminated the Sales Agreement. On August 13, 2021, the Company entered into a new Sales Agreement (the “2021 Sales Agreement”) with SVB Leerink with respect to an at-the-market offering program under which the Company may offer and sell, from time to time at its sole discretion, shares of its common stock having an aggregate offering price of up to $50.0 million through SVB Leerink as its sales agent. As of September 30, 2021, Company had not offered or sold any common stock under the 2021 Sales Agreement. On May 6, 2021, the Company entered into an underwriting agreement with SVB Leerink, as representative of the underwriters, relating to an underwritten public offering of 10.4 million shares of the Company’s common stock. The underwritten public offering resulted in gross proceeds of $ 73.1 million. The Company incurred $ 4.4 million in issuance costs and $ 0.5 million of professional fees associated with the underwritten public offering, resulting in net proceeds to the Company of $ 68.2 million. Warrants In connection with the entry into the Loan and Security Agreement (refer to Note 8), the Company has issued to Horizon warrants to purchase an aggregate number of shares of the Company’s common stock in an amount equal to $ 100,000 divided by the exercise price for each respective warrant. If at any time the Company files a registration statement relating to an offering for its own account, or the account of others, of any of its equity securities, the Company has agreed to include such number of shares underlying the warrants in such registration statement as requested by the holder. The warrants, which are exercisable for an aggregate of 42,236 shares, will be exercisable for a period of seven years at a per-share exercise price of $ 9.47 , which is equal to the 10 -day average closing price prior to January 15, 2021, the date on which the term sheet relating to the Loan and Security Agreement was entered into, subject to certain adjustments as specified in the warrant. At September 30, 2021 , there were 42,236 warrants outstanding. A summary of the warrant activity for the nine months ended September 30, 2021, is as follows: Warrants Outstanding at December 31, 2020 144,384 Exercises ( 51,054 ) Issued 42,236 Expired ( 10,837 ) Outstanding at September 30, 2021 124,729

Stock Option Plans

Stock Option Plans	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Stock Option Plans	10. Stock Option Plans Incentive Plans The Company maintains two equity incentive plans (the "Plans") that provide for the granting of stock options , share appreciation rights, restricted shares, restricted share units, performance share units and certain other share based awards as provided in the Plans to certain employees, members of the board of directors, consultants or other service providers of the Comp any, with a prescribed contractual term not to exceed ten years. As of September 30, 2021, there were 196,910 shares of common stock available for grant under the Plans. Awards granted under the Plans generally vest over a four-year period with 25 % or 28 % of the award vesting on the first anniversary of the commencement date and the balance vesting monthly over the remaining three years. Grants are generally awarded with a contractual terms of 10 years from the date of the grant. For certain senior members of management and directors, the board of directors approved an alternative vesting schedule. The share reserve under one of the Plans automatically increases on January 1 st each year, in an amount equal to 4 % of the total number of shares outstanding as of December 31 of the preceding year. Stock option valuation The fair value of stock option grants is estimated using the Black-Scholes option-pricing model with the following assumptions: Black-Scholes Option- September 30, December 31, Risk-free interest rate 0.76 %- 0.86 % 0.17 % – 0.42 % Expected volatility 92.9 % 82.8 %- 98.3 % Expected dividend yield 0 % 0 % Expected life (in years) 5.1 5.1 The table below summarizes stock option activity under the Company’s stock option plans: Stock Option Activity Number of Weighted Weighted Aggregate (in years) (in thousands) Outstanding as of December 31, 2020 533,559 $ 3.33 9.30 $ 8,494 Granted 624,986 7.76 8.99 ( 1,008 ) Exercised ( 19,805 ) 0.12 8.15 500 Forfeited and expired ( 55,550 ) 5.98 9.38 157 Outstanding as of September 30, 2021 1,083,190 5.80 8.98 6,011 Options exercisable at September, 2021 232,626 5.86 8.26 2,801 The weighted average grant date fair value of options granted during the nine months ended September 30, 2021 and 2020 was $ 6.15 and $ 1.65 per share, respectively. The total fair value of options vested during the nine months ended September 30, 2021 and 2020 was $ 4.2 million and $ 4.4 million, respectively. Restricted Stock Units Time-Based Restricted Stock Units (RSU) In February 2021, the Company issued 310,385 time-based RSUs to employees and directors under the Amended and Restated 2015 Plan. The weighted average grant date fair value of the time-based RSUs was $ 8.57 f or the nine months ended September 30, 2021. The vesting for the time-based RSUs occurs either immediately, after one year or after four years. For the three and nine months ended September 30, 2021, the Company recognized approximatel y $ 0.4 million and $ 1.8 mill ion in expenses related to the time-based RSUs. The table below is a rollforward of all RSU activity under the Stock Incentive Plans The table below summarizes activity relating to RSUs for the nine months ended September 30, 2021: RSU Activity Restricted Weighted- Total nonvested units at December 31, 2020 69,749 $ 11.73 Granted 310,385 8.57 Vested ( 83,889 ) 9.34 Total nonvested units at September 30, 2021 296,245 $ 9.10 Share-based Compensation The Company recorded share-based compensation expense in the following expense categories for the three and nine months ended September 30, 2021 and 2020 of its consolidated statements of operations and comprehensive loss (in thousands): Share-Based Compensation For the Three Months For the Nine Months 2021 2020 2021 2020 Research and development expenses $ 1,115 $ 1,135 $ 4,197 $ 1,682 General and administrative expenses 400 59 1,357 517 $ 1,515 $ 1,194 $ 5,554 $ 2,199 At September 30, 2021 , there was $ 4.4 million of unrecognized stock-based compensation expense relating to stock options granted pursuant to the Stock Incentive Plans, which will be recognized over the weighted-average remaining vesting period of 2.7 years. At September 30, 2021 , there was $ 1.5 million of unrecognized stock-based compensation expense relating to the time-based RSUs granted pursuant to the Stock Incentive Plans, which will be recognized over the weighted-average remaining vesting period of 3.0 years.

Significant Agreements

Significant Agreements	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Significant Agreements	11. Significant Agreements License and Collaboration agreements For the nine months ended September 30, 2021 and 2020, the Company had License and Collaboration agreements (“LCAs”) with Denali, Ares and AstraZeneca. The following table summarizes the revenue recognized in the Company’s consolidated statements of operations and comprehensive loss from these arrangements (in thousands): Revenue by Collaboration Partner For the Three Months For the Nine Months 2021 2020 2021 2020 Ares $ — 8,691 2,800 9,945 Denali — 504 117 1,148 AstraZeneca 500 $ — 500 $ — Other 251 $ — 251 $ — Total $ 751 $ 9,195 $ 3,668 $ 11,093 2019 License and collaboration agreement with Ares Trading S.A. Summary On May 13, 2019, the Company entered into a licensing and collaboration agreement ("2019 LCA") with Ares, pursuant to which the Company granted the option to enter into a worldwide, exclusive license to certain patents and know-how to develop, manufacture and commercialize two separate mAb 2 antibody products that each contain a specific Fcab and a Fab target pair (each a licensed product). For the exclusive rights granted in relation to the first molecule, an option fee of $ 11.1 million was paid by Ares to the Company. Following receipt of the option fee, Ares became responsible for the development of the molecule and development, regulatory and sales-based royalties become payable to Company upon achievement of specified events. On July 15, 2020, a deed of amendment (the “2020 Amendment”) was entered into in respect of the 2019 LCA. The 2020 Amendment had two main purposes (i) to grant additional options to acquire intellectual property rights for a third and fourth molecule; and (ii) to allow Ares to exercise its option early to acquire intellectual property rights to the second molecule included in the 2019 LCA as well as to terminate the R&D services. An option fee of $ 8.5 million was paid by Ares to the Company on exercise of the option to acquire rights to the second molecule. During March 2021 Ares paid an option fee of $ 2.7 million to acquire the rights to the third molecule. As a result of the 2020 Amendment, the maximum amount payable by Ares on the achievement of certain development and regulatory milestones in the aggregate was increased to $ 473.9 million, and the maximum amount payable on the achievement of certain commercial milestones was increased to $ 292.3 million. 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 basis. Revenue recognition Management has considered the performance obligations identified in the Ares LCA and concluded that the option for the grant of intellectual property rights is not distinct from the provision of R&D services, as the R&D services would 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 each individual molecule included in the 2019 LCA. The Company recognized revenue using the cost-to-cost method, which it believes best depicted 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. The total transaction price for the 2019 LCA, was initially determined to be $ 15.4 million, consisting of the upfront payment for the first molecule and research and development funding for the research term for the second molecule. 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. There were two components identified in the 2020 Amendment, each of which was accounted for as a separate performance obligation. The first component, the grant of the additional options to acquire intellectual property rights for the third and fourth molecule, 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 2019 LCA. 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, which allowed the customer to exercise its option to acquire intellectual property rights to the second molecule early, is considered to be a modification of the 2019 LCA. This is because the option is not independent of the R&D services provided under the 2019 LCA, 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. For the three and nine months ended September 30, 2020 , $ 0.2 million and $ 1.5 million was recognized in relation to the first antibody included in the 2020 Amendment. During the nine months ended September 30, 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 and $ 2.7 million was recognized at a point in time in respect of the option exercise. License and collaboration agreement with Denali Therapeutics, Inc. Summary In August 2016 the Company entered into an exclusive license and collaboration agreement (the “Denali LCA”) with Denali. Under the terms of the Denali LCA, Denali was granted the right to nominate up to three Fcab targets for approval (“Accepted Fcab Targets”), within the first three years of the date of the agreement. Upon entering into the Denali LCA, Denali had selected Transferrin receptor as the first Accepted Fcab Target and paid an upfront fee of $ 5.5 million to the Company. In May 2018, Denali exercised its right to nominate two additional Fcab targets and identified a second Accepted Fcab Target. Denali made a one-time payment to the F-star group for the two additional Accepted Fcab Targets of $ 6.0 million and extended the time period for its selection of the third Accepted Fcab Target until August 2020. Under the terms of the agreement the Company is entitled to receive contingent payments that relate to certain defined preclinical, clinical, regulatory, and commercial milestones with a maximum value of $ 49.5 million. 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. The initial transaction price for the second Accepted Fcab target was $ 5.1 million, 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 Denali LCA was not included in the transaction price, as it was not deemed probable that a reversal would not occur in a future reporting period. All performance obligations were deemed to have been fully satisfied during the year ended December 31, 2019 in respect of the first Accepted Fcab Target, and during the three months ended March 30, 2021 in respect of the second Accepted Fcab Target. As a result, no revenue was recognized in respect of these targets for the three months ended September 30, 2021. In respect of the second Accepted Fcab Target, for the nine months ended September 30, 2021 and 2020 , the Company recognized $ 0.1 million and $ 1.1 million, respectively, and for the three months ended September 30, 2020 , the Company recognized $ 0.5 million. 2021 Agreement with AstraZeneca Summary On July 7, 2021 the Company entered into a License Agreement with AstraZeneca AB. Under the terms of the agreement the Company has granted an exclusive license to certain patents and know-how to develop, manufacture and commercialize STING inhibitor compounds. AstraZeneca will be responsible for all future research, development and commercialization activities. For the exclusive rights granted, an initial upfront fee of $ 0.5 million was paid by AstraZeneca to the Company during the three months ended September 2021. The Company is entitled to receive additional contingent near-term preclinical milestones of $ 11.5 million, plus maximum contingent payments that relate to certain defined development and regulatory milestones of $ 96.5 million and commercial milestones of $ 221.3 million, as well as royalty payments based upon a single digit percentage on net sales of products developed. Pursuant to the STING Antagonist CVR Agreement, 80 % of net proceeds received the Company under the License Agreement with AstraZeneca will be payable, pursuant to the Exchange Agreement, to common stockholders of Spring Bank as of November 19, 2020, immediately prior to the Closing of the transaction. Revenue recognition Management has identified a single performance obligation in the contract, which is the grant of intellectual property rights. The total transaction price was initially determined to be $ 0.5 million, consisting only of the upfront payment. Variable consideration to be paid to the company upon reaching certain milestones has been excluded from the calculation, as at the inception of the contract, it is not probable that a significant reversal of revenue recognized would not occur in a subsequent reporting period. The transaction price was allocated to the single performance obligation, which was deemed to be fully satisfied on the grant of intellectual property rights, and therefore the initial upfront fee was recognized at a point in time. In the three and nine months ended September 30, 2021, the Company recorded revenue of $ 0.5 million in respect of this contract. Summary of Contract Assets and Liabilities Up-front payments and fees are recorded as deferred revenue upon receipt or when due until such time as the Company satisfies its performance obligations under these arrangements. A contract asset is a conditional right to consideration in exchange for goods or services that the Company has transferred to a customer. Amounts are recorded as accounts receivable when the Company’s right to consideration is unconditional. The following table presents changes in the balances of the Company’s contract liabilities (in thousands): Deferred Additions Revenue Impact of Deferred Deferred revenue Ares collaboration $ 37 $ — $ ( 37 ) $ — $ — Denali collaboration 263 — ( 117 ) ( 146 ) — Total deferred revenue $ 300 $ — $ ( 154 ) $ ( 146 ) $ — During the nine months ended September 30, 2021 , 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.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	12. Commitments and Contingencies Lease Obligations On January 27, 2021, the Company signed an operating lease for three years for its corporate headquarters in Cambridge, United Kingdom, which has approximately 2.3 years remaining. The Company also has leases for the former Spring Bank headquarters and laboratory space in Hopkinton, Massachusetts, which are being subleased. The Company’s leases have remaining lease terms of approximately 7.1 years for its former principal office and laboratory space, which includes an option to extend the lease for up to five years . The Company’s former locations are being subleased through the remainder of the lease term. Operating lease costs under the leases for the nine months ended September 30, 2021, were approximately $ 0.8 million. The following table summarizes the Company’s maturities of operating lease liabilities as of September 30, 2021 (in thousands): Maturities of Operating Lease Liabilities Periods For the period October 1, 2021 to December 31, 2021 $ 242 2022 978 2023 990 2024 474 2025 486 Thereafter 1,444 Total lease payments $ 4,614 Sublease The Company subleases the former Spring Bank offices in Hopkinton, Massachusetts. Operating sublease income under operating lease agreements for the nine months ended September 30, 2021 , was $ 0.4 million. This sublease has a remaining lease terms of 7.1 years. Future expected cash receipts from our sublease as of September 30, 2021, are as follows (in thousands): Future Expected Cash Receipts From Sublease Period For the period October 1, 2021 to December 31, 2021 $ 56 2022 462 2023 474 2024 486 2025 498 Thereafter 1,481 Total sublease receipts $ 3,457 Service Agreements As of September 30, 2021 , the Company had contractual commitments of $ 2.6 million with a contract manufacturing organization (“CMO”) for activities that are ongoing or are scheduled to start between three and nine 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 three, six or nine months prior to the commencement date. Contingent value rights The acquisition-date fair value of the Contingent Value Rights ("CVR") liability represents the future payments that are contingent upon the achievement of sale or licensing 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. The current liability of the CVR was $0.6 million and $2.1 million at September 30, 2021 and December 31, 2020, respectively. The long term liability of the CVR was $2.9 million and $0.4 million at September 30, 2021 and December 31, 2020, respectively. Changes in the fair value of the liability will be recognized in the consolidated statement of operations and comprehensive loss until settlement.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2021
Subsequent Events [Abstract]
Subsequent Events	13. Subsequent Events On October 19, 2021, the Company entered into a License and Collaboration Agreement with Janssen Biotech, Inc., one of the Janssen Pharmaceutical Companies of Johnson & Johnson. The agreement was facilitated by Johnson & Johnson Innovation. Under the terms of the agreement, F-star has granted Janssen a worldwide, exclusive royalty-bearing license to research, develop, and commercialize up to five novel bispecific antibodies directed to Janssen therapeutic targets using F-star’s proprietary Fcab™ and mAb 2 ™ platforms. Janssen will be responsible for all research, development and commercialization activities under the agreement. Under the terms of the agreement F-star is entitled to receive upfront fees of $ 17.5 million with total potential income of up to $ 1.35 billion. F-star is also eligible to receive potential tiered mid-single digit royalties on annual net sales.

Nature of Business and Summar_2

Nature of Business and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles (“U.S. GAAP”) and the rules and regulations of the Securities Exchange Commission ("SEC") for interim financial statements. The accompanying interim condensed consolidated financial statements as of September 30, 2021, and for the three and nine months ended September 30, 2021 and 2020, and information contained within the notes to these condensed consolidated financial statements, are unaudited. These unaudited interim condensed consolidated financial statements have been prepared on the same basis as the Company’s audited annual financial statements and in management's opinion contain all adjustrevisionments (including normal recurring adjustments) necessary for the fair presentation of the Company’s financial position as of September 30, 2021, results of operations for the three and nine months ended September 30, 2021 and 2020, statement of stockholders’ equity for the three and nine months ended September 30, 2021 and 2020 and its cash flows for the nine months ended September 30, 2021 and 2020. These interim condensed consolidated financial statements should be read in conjunction with the Company’s annual audited financial statements and notes thereto included in the Company’s Annual Report filed on SEC Form 10-K for the year ended December 31, 2020. The results for the three and nine months ended September 30, 2021, are not necessarily indicative of the results expected for the full fiscal year or any interim period. Revision of Previously Issued Financial Statements In September 2021, the Company identified an error in its accounting treatment for research and development expenses. This error resulted in an overstatement of research and development expenses for the first six months of 2021 and accrued expenses and other current liabilities as of March 31, 2021 and June 30, 2021. The Company assessed the materiality of this error on prior period financial statements in accordance with the SEC Staff Accounting Bulletin Number 99, Materiality, and ASC 250-10, Accounting Changes and Error Corrections. The Company determined that this error was not material to the financial statements of any prior interim period. To correct the immaterial misstatement, the Company decreased accumulated deficit by $ 0.3 million as of June 30, 2021.
Principles of Consolidation	Principles of Consolidation The Company’s interim condensed consolidated financial statements have been prepared in conformity with U.S. GAAP. Any reference in these notes to applicable guidance is meant to refer to the authoritative U.S. GAAP as found in the ASC and Accounting Standards Updates (“ASU”) of the FASB. The accompanying condensed consolidated financial statements include the accounts of F-star Therapeutics, Inc. and its wholly owned subsidiaries. All inter-company balances and transactions between the consolidated companies have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of the condensed consolidated financial statements in conformity with U.S. 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 condensed consolidated financial statements and the reported amounts of expenses during the reporting years. Significant estimates and assumptions reflected in these condensed 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 Ltd fair value of the convertible loan containing embedded derivatives, the fair value of contingent value rights, the accrual for research and development expenses, revenue recognition, fair values of acquired intangible assets and impairment review of those assets, warrants, share based compensation expense, and income taxes. The Company bases its estimates on historical experience, known trends and other market-specific or other relevant factors that it believes to be reasonable under the circumstances. Estimates are periodically reviewed in light of reasonable changes in circumstances, facts and experience. Changes in estimates are recorded in the period in which they become known. Actual results could differ from those estimates or assumptions.
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 contract research organizations to provide its clinical trials and 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.
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
Leases	Leases The Company determines if an arrangement is a lease at inception. Operating leases are included in right-of-use (“ROU”) assets, and lease obligations in the Company’s consolidated balance sheets. ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent its obligation to make lease payments arising from the lease. Operating 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 an incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. This is the rate the Company would have to pay if borrowing on a collateralized basis over a similar term to each lease. The operating lease ROU asset also includes any lease payments made and excludes 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. Lease expense for lease payments is recognized on a straight-line basis over the lease term.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets Long-lived assets to be held and used are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable. When such events occur, the Company compares the carrying amounts of the assets to their undiscounted expected future cash flows. If the undiscounted cash flows are insufficient to recover the carrying value, an impairment loss is recorded for the difference between the carrying value and fair value of the asset. As of September 30, 2021 , no such impairment has been recorded.
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 bispecific antibody platform, (ii) performing research and development services to optimize drug candidates, and (iii) the grant of options to obtain additional research and development services or licenses for additional targets, or to optimize product candidates, upon the payment of option fees. The terms of these arrangements typically include payment to the Company of one or more of the following: non-refundable, upfront license fees; payments for research and development services; fees upon the exercise of options to obtain additional services or licenses; payments based upon the achievement of defined collaboration objectives; future regulatory and sales-based milestone payments; and royalties on net sales of future products. The Company has adopted FASB 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. (“Denali”), Ares Trading S.A. (“Ares,”) an affiliate of Merck KGaA, Darmstadt, Germany) and in July 2021 with AstraZeneca AB ("AstraZeneca"), which were determined to be within the scope of ASC 606.
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 compensation expense, 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 to 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.
Warrants	Warrants The Company accounts for warrants within stockholders equity or as liabilities based on the characteristics and provisions of each instrument. The Company evaluates outstanding warrants in accordance with ASC 480, Distinguishing Liabilities from Equity , and ASC 815, Derivatives and Hedging . If none of the criteria in the evaluation in these standards are met, the warrants are classified as a component of stockholders’ equity and initially recorded at their grant date fair value without subsequent remeasurement. Warrants that meet the criteria are classified as liabilities and remeasured to their fair value at the end of each reporting period.
Stock-Based Compensation	Stock-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.
Fair value measurements of financial instruments	Fair value measurements of financial instruments The Company’s financial instruments consist of cash, accounts payable, CVRs 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 CVRs and the liability classified warrants are remeasured to fair value each reporting period.
Net loss per share	Net loss per share The Company computes net loss 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 considered participating securities and are included in the calculation of basic and diluted net (loss) income per share using the two-class method. In periods where the Company reports net losses, such losses are not allocated to the convertible preferred shares for the computation of basic or diluted net (loss) income. 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.
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. The potential recovery of deferred tax assets is evaluated by estimating the potential for future taxable profits, if any. Research and development tax credit As the entities located in the United Kingdom carry out extensive research and development activities, they seek to benefit from the UK research and development tax credit cash rebate regime known as the Small and Medium-sized Enterprises R&D Tax Credit Program (the “SME Program”). Qualifying expenditures largely comprise employment costs for research staff, consumables expenses incurred under agreements with third parties that conduct research and development, preclinical activities, clinical activities and manufacturing on the Company’s behalf and certain internal overhead costs incurred as part of research projects. The tax credit received in the United Kingdom pursuant to the SME Program permits companies to deduct an extra 130 % of their qualifying costs from their yearly profit or loss, as well as the normal 100 % deduction, to make a total 230 % deduction. If the company is incurring losses, it is entitled to claim a tax credit worth up to 14.5 % of the surrenderable loss. To qualify for relief under the SME Program, companies are required to employ fewer than 500 staff and have a turnover of under €100.0 million or a balance sheet total of less than €86.0 million. Research and development tax credits received in the United Kingdom are recorded as a reduction in research and development expenses. The UK research and development tax credit is payable to companies after surrendering tax losses and is not dependent on current or future taxable income. As a result, it is not reflected as part of the income tax provision. During the nine months ended September 30, 2021 the Company received $ 3.4 million in research and development tax credits related to the year ended December 31, 2020 .
Contingencies	Contingencies Liabilities for loss contingencies arising from claims, assessments, litigation, fines, penalties, and other sources are reco rded 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.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In June 2016, the FASB issued ASU No. 2016-13, Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”). ASU 2016-13 will change how companies account for credit losses for most financial assets and certain other instruments. For trade receivables, loans and held-to-maturity debt securities, companies will be required to recognize an allowance for credit losses rather than reducing the carrying value of the asset. In November 2019, the FASB issued ASU No. 2019-10, Financial Instruments — Credit Losses (Topic 326), Derivatives and Hedging (Topic 815), and Leases (Topic 842): Effective Dates to amend the effective date of ASU 2016-13, for entities eligible to be “smaller reporting companies,” as defined by the SEC, to be effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. Early adoption is permitted. The Company has not elected to early adopt ASU No. 2016-13. The Company is currently evaluating the potential impact that the adoption of ASU 2016-13 will have on the Company’s financial position and results of operations.

Nature of Business and Summar_3

Nature of Business and Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2021
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)	9 Months Ended
	Sep. 30, 2021
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	The purchase price is allocated to the fair value of assets and liabilities acquired as follows in the table below (in thousands, except shares of common stock and fair value per share): Purchase Price Allocation 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 ( 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

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Summary of Computation of Basic and Diluted Net Loss Per Share	The following table presents the calculation of basic and diluted net loss per share applicable to common stockholders of the Company (in thousands, except share and per share data): Net Loss Per Share For the Three Months For the Nine Months 2021 2020 2021 2020 Net loss $ ( 10,791 ) $ ( 3,451 ) $ ( 36,024 ) $ ( 17,072 ) Weighted average number shares 20,617,822 1,832,194 15,300,433 1,828,597 Net loss income per common, basic $ ( 0.52 ) $ ( 1.88 ) $ ( 2.35 ) $ ( 9.34 )
Summary of Potentially Dilutive Securities Outstanding Excluded from Computation of Diluted Weighted-Average Shares Outstanding	The following shares were excluded from the calculation of diluted net loss per share, prior to the use of the treasury stock method or if-converted method, because their effect would have been anti-dilutive for the period presented: Potential Dilutive Shares For the Three and Nine Months 2021 2020 Convertible debt shares — 185,732 Common stock warrants 124,729 481,781 Stock options and RSUs 528,871 1,660,906

In Process R&D and Intangible_2

In Process R&D and Intangible Assets, Net (Tables)	9 Months Ended
	Sep. 30, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of In Process R&D and Intangible Assets	September 30, 2021 December 31, 2020 In-process R&D Intangible assets Total In-process R&D Intangible assets Total Cost $ 18,912 $ 4,469 $ 23,381 $ 23,554 $ — $ 23,554 Less: accumulated amortization — 65 65 — — — Less: impairments 4,526 — 4,526 4,568 — 4,568 $ 14,386 $ 4,404 $ 18,790 $ 18,986 $ — $ 18,986

Property, Plant and Equipment_2

Property, Plant and Equipment, net (Tables)	9 Months Ended
	Sep. 30, 2021
Property, Plant and Equipment [Abstract]
Schedule of Property, Plant and Equipment, net	Property, plant and equipment, net consisted of the following (in thousands): Property, Plant and Equipment, net September 30, December 31, 2021 2020 Leasehold improvements $ 203 $ 15 Laboratory equipment 2,211 1,788 Furniture and office equipment 161 169 2,575 1,972 Less: Accumulated depreciation 1,564 1,183 $ 1,011 $ 789

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2021
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 September 30, 2021 Using: Level 1 Level 2 Level 3 Total Liabilities: Contingent value rights $ — $ — $ 3,547 $ 3,547 Warrants — — 11 11 $ — $ — $ 3,558 $ 3,558 Fair Value Measurements as of December 31, 2020 Using: Level 1 Level 2 Level 3 Total Liabilities: Contingent value rights $ — $ — $ 2,520 $ 2,520 Warrants — — 37 37 $ — $ — $ 2,557 $ 2,557
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 warrants, for the nine months ended September 30, 2021 (in thousands): Change in Level 3 Liabilities November 2016 Private Contingent Value Balance at December 31, 2020 $ 37 $ 2,520 Warrants exercised ( 26 ) — Change in fair value of CVR — 1,027 Balance at September 30, 2021 $ 11 $ 3,547

Accrued Expenses and other Cu_2

Accrued Expenses and other Current Liabilities (Tables)	9 Months Ended
	Sep. 30, 2021
Payables and Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses as of September 30, 2021 and December 31, 2020, consisted of the following (in thousands): September 30, December 31, 2021 2020 Clinical Trial Costs $ 2,764 $ 3,394 Severance 6 1,953 Compensation and Benefits 1,440 1,361 Professional Fees 735 1,593 Other 697 1,160 $ 5,642 $ 9,461

Term Debt (Tables)

Term Debt (Tables)	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Summary of Debt	The Company’s debt obligation consisted of the following (in thousands) Term Debt September 30, December 31, Term Loan A and B due April 2025 $ 5,000 $ — Term Loan C and D due June 2025 5,000 — Term debt 10,000 — Less: Unamortized deferred issuance costs ( 216 ) — Less: Warrant discount and interest ( 249 ) — Total debt obligations- long term $ 9,535 $ —

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2021
Equity [Abstract]
Summary of Warrant Activity	A summary of the warrant activity for the nine months ended September 30, 2021, is as follows: Warrants Outstanding at December 31, 2020 144,384 Exercises ( 51,054 ) Issued 42,236 Expired ( 10,837 ) Outstanding at September 30, 2021 124,729

Stock Option Plans (Tables)

Stock Option Plans (Tables)	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Summary of Stock Option Valuation	Stock option valuation The fair value of stock option grants is estimated using the Black-Scholes option-pricing model with the following assumptions: Black-Scholes Option- September 30, December 31, Risk-free interest rate 0.76 %- 0.86 % 0.17 % – 0.42 % Expected volatility 92.9 % 82.8 %- 98.3 % Expected dividend yield 0 % 0 % Expected life (in years) 5.1 5.1
Summary of Option Activity	The table below summarizes stock option activity under the Company’s stock option plans: Stock Option Activity Number of Weighted Weighted Aggregate (in years) (in thousands) Outstanding as of December 31, 2020 533,559 $ 3.33 9.30 $ 8,494 Granted 624,986 7.76 8.99 ( 1,008 ) Exercised ( 19,805 ) 0.12 8.15 500 Forfeited and expired ( 55,550 ) 5.98 9.38 157 Outstanding as of September 30, 2021 1,083,190 5.80 8.98 6,011 Options exercisable at September, 2021 232,626 5.86 8.26 2,801
Summary of RSU Activity	The table below is a rollforward of all RSU activity under the Stock Incentive Plans The table below summarizes activity relating to RSUs for the nine months ended September 30, 2021: RSU Activity Restricted Weighted- Total nonvested units at December 31, 2020 69,749 $ 11.73 Granted 310,385 8.57 Vested ( 83,889 ) 9.34 Total nonvested units at September 30, 2021 296,245 $ 9.10
Summary of Stock-Based Compensation Expense	The Company recorded share-based compensation expense in the following expense categories for the three and nine months ended September 30, 2021 and 2020 of its consolidated statements of operations and comprehensive loss (in thousands): Share-Based Compensation For the Three Months For the Nine Months 2021 2020 2021 2020 Research and development expenses $ 1,115 $ 1,135 $ 4,197 $ 1,682 General and administrative expenses 400 59 1,357 517 $ 1,515 $ 1,194 $ 5,554 $ 2,199

Significant Agreements (Tables)

Significant Agreements (Tables)	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of License and Collaboration Agreements	For the nine months ended September 30, 2021 and 2020, the Company had License and Collaboration agreements (“LCAs”) with Denali, Ares and AstraZeneca. The following table summarizes the revenue recognized in the Company’s consolidated statements of operations and comprehensive loss from these arrangements (in thousands): Revenue by Collaboration Partner For the Three Months For the Nine Months 2021 2020 2021 2020 Ares $ — 8,691 2,800 9,945 Denali — 504 117 1,148 AstraZeneca 500 $ — 500 $ — Other 251 $ — 251 $ — Total $ 751 $ 9,195 $ 3,668 $ 11,093
Summary of Contract Assets and Liabilities	The following table presents changes in the balances of the Company’s contract liabilities (in thousands): Deferred Additions Revenue Impact of Deferred Deferred revenue Ares collaboration $ 37 $ — $ ( 37 ) $ — $ — Denali collaboration 263 — ( 117 ) ( 146 ) — Total deferred revenue $ 300 $ — $ ( 154 ) $ ( 146 ) $ —

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2021
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 September 30, 2021 (in thousands): Maturities of Operating Lease Liabilities Periods For the period October 1, 2021 to December 31, 2021 $ 242 2022 978 2023 990 2024 474 2025 486 Thereafter 1,444 Total lease payments $ 4,614
Summary of Future expected cash receipts from subleases	Future expected cash receipts from our sublease as of September 30, 2021, are as follows (in thousands): Future Expected Cash Receipts From Sublease Period For the period October 1, 2021 to December 31, 2021 $ 56 2022 462 2023 474 2024 486 2025 498 Thereafter 1,481 Total sublease receipts $ 3,457

Nature of Business and Summar_4

Nature of Business and Summary of Significant Accounting Policies - Summary of Estimated Useful Lives of Property and Equipment (Detail)	9 Months Ended
	Sep. 30, 2021
Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	Lesser of lease term or useful life

Nature of Business and Summar_5

Nature of Business and Summary of Significant Accounting Policies - Additional Information (Detail) $ / shares in Units, $ in Thousands	Jun. 22, 2021USD ($)	May 06, 2021USD ($)$ / sharesshares	Apr. 01, 2021USD ($)Loan	Nov. 20, 2020	Jun. 30, 2021USD ($)shares	Sep. 30, 2021USD ($)$ / sharesshares	Sep. 30, 2020USD ($)	Aug. 13, 2021USD ($)	Mar. 30, 2021USD ($)$ / shares	Dec. 31, 2020USD ($)$ / sharesshares
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Stockholders' Equity, Reverse Stock Split				1-for-4
Common stock, par value | $ / shares						$ 0.0001				$ 0.0001
Common stock, shares issued | shares						20,623,041				9,100,117
Gross proceeds from issuance of common stock						$ 9,115
Proceeds from issuance of Common Stock						77,295	$ 0
Accumulated deficit						$ 83,192				$ 47,168
Significant conditions or events						F-star expects to incur substantial losses in the foreseeable future as it conducts and expands its research and development activities and clinical trial activities. As of September 30, 2021, the Company had cash of $71.1 million and working capital of $67.3 million. As of November 10, 2021, the date of issuance of the condensed consolidated financial statements, the Company’s cash and cash equivalents on hand will be sufficient to fund its current operating plan and planned capital expenditures for at least the next 12 months.
Cash						$ 71,100
Working capital						67,300
Impairment of long-lived assets						0
Tax repayment for research and development						$ 3,400
Research Development Tax [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Extra deduction under UK tax credit percentage						130.00%
Normal deduction from UK tax credit percentage						100.00%
Total deductions under UK tax credit percentage						230.00%
Research and development tax credit percentage						14.50%
Condition to qualify under SME program						To qualify for relief under the SME Program, companies are required to employ fewer than 500 staff and have a turnover of under €100.0 million or a balance sheet total of less than €86.0 million.
Prior Period Adjustment [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Accumulated deficit					$ 300
Term Loan [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Number of loans | Loan			4
Long-term line of credit			$ 2,500
Proceeds from lines of credit	$ 5,000		$ 5,000
SBPH Sales Agreement [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Common stock, par value | $ / shares		$ 0.0001							$ 0.0001
Aggregate offering price									$ 50,000
Common stock, shares issued | shares		979,843			979,843
Gross proceeds from issuance of common stock		$ 9,500			$ 9,500
Proceeds from issuance of Common Stock		9,100			$ 9,200
Proceeds from initial public offer		10,400
2021 Sales Agreement [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Aggregate offering price								$ 50,000
Common stock, shares issued | shares						0
IPO [Member] | SBPH Sales Agreement [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Gross proceeds from issuance of common stock		73,100
Proceeds from issuance of Common Stock		68,200
Issuance cost		4,400
Professional fees		$ 500

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	Sep. 30, 2021
Business Acquisition [Line Items]
Goodwill		$ 14,926	$ 14,885
Contingent value rights		$ (440)	$ (2,899)
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 - Addition

Business Combination - Additional Information (Detail) - USD ($) $ in Thousands	Nov. 20, 2020	Dec. 31, 2020
Spring Bank [member]
Business Acquisition [Line Items]
Consideration	$ 21,500	$ 21,536

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	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Earnings Per Share, Basic and Diluted [Abstract]
Net loss	$ (10,791)	$ (3,451)	$ (36,024)	$ (17,072)
Weighted average number shares outstanding, basic and diluted	20,617,822	1,832,194	15,300,433	1,828,597
Net loss income per common, basic and diluted	$ (0.52)	$ (1.88)	$ (2.35)	$ (9.34)

Net Loss Per Share - Summary _2

Net Loss Per Share - Summary of Potentially Dilutive Securities Outstanding Excluded from Computation of Diluted Weighted-Average Shares Outstanding (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Convertible Debt Shares [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities outstanding excluded from the computation of diluted weighted-average shares outstanding	0	185,732	0	185,732
Common Stock Warrants [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities outstanding excluded from the computation of diluted weighted-average shares outstanding	124,729	481,781	124,729	481,781
Stock Options and RSU [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities outstanding excluded from the computation of diluted weighted-average shares outstanding	528,871	1,660,906	528,871	1,660,906

In Process R&D and Intangible_3

In Process R&D and Intangible Assets, Net - Summary of In Process R&D and Intangible Assets (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Cost	$ 23,381	$ 23,554
Less: accumulated amortization	65	0
Less: impairments	4,526	4,568
In-process R&D assets and Intangible assets	18,790	18,986
In-Process R&D [Member]
Cost	18,912	23,554
Less: accumulated amortization	0	0
Less: impairments	4,526	4,568
In-process R&D assets and Intangible assets	14,386	18,986
Intangible Assets [Member]
Cost	4,469
Less: accumulated amortization	65	0
Less: impairments	0
In-process R&D assets and Intangible assets	$ 4,404

In Process R&D and Intangible_4

In Process R&D and Intangible Assets, Net - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
In-process R&D assets and Intangible assets	$ 18,790	$ 18,790		$ 18,986
Percentage of assets realized		95.00%
Amortization	100	$ 65	$ 0
Reclassification [Member]
In-process R&D assets and Intangible assets	$ 4,500	$ 4,500

Property, Plant and Equipment_3

Property, Plant and Equipment, net - Schedule of Property, Plant and Equipment, net (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 2,575	$ 1,972
Less: Accumulated depreciation	1,564	1,183
Property and equipment, net	1,011	789
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	203	15
Laboratory Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	2,211	1,788
Furniture and Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 161	$ 169

Property, Plant and Equipment_4

Property, Plant and Equipment, net - Additional Information (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 435	$ 887

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Assets and Liabilities Measured at Fair Value (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities, Total	$ 3,558	$ 2,557
Contingent Value Rights [member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities, Total	3,547	2,520
Warrant Liabilities [member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities, Total	11	37
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities, Total	3,558	2,557
Level 3 | Contingent Value Rights [member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities, Total	3,547	2,520
Level 3 | Warrant Liabilities [member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities, Total	$ 11	$ 37

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of change in the Company's Level 3 liabilities, liability based warrants outstanding (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Change in fair value of CVR	$ (444)	$ 0	$ (1,027)	$ 0
Level 3 | Contingent Value Right [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Balance at December 31, 2020			2,520
Warrants exercised			0
Change in fair value of CVR			1,027
Balance at September 30, 2021	3,547		3,547
Level 3 | Private Placement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Balance at December 31, 2020			37
Warrants exercised			(26)
Change in fair value of CVR			0
Balance at September 30, 2021	$ 11		$ 11

Accrued Expenses and other Cu_3

Accrued Expenses and other Current Liabilities - Schedule of Accrued Expenses (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Accrued Liabilities and Other Liabilities [Abstract]
Clinical Trial Costs	$ 2,764	$ 3,394
Severance	6	1,953
Compensation and Benefits	1,440	1,361
Professional Fees	735	1,593
Other	697	1,160
Total Accrued expenses and other current liabilities	$ 5,642	$ 9,461

Term Debt - Additional Informat

Term Debt - Additional Information (Detail) $ in Thousands	Jun. 22, 2021USD ($)	Apr. 01, 2021USD ($)Loan	Sep. 30, 2021USD ($)	Sep. 30, 2020USD ($)
Debt Disclosure [Line Items]
Maturity period			48 months
Line of credit facility, interest rate at period end			6.25%
Line of credit facility, interest rate during period			3.25%
Line of credit facility, commitment fee percentage			3.25%
Line of credit facility, frequency of payment and payment terms			The Company may, at its option upon at least five business days’ written notice to Horizon, prepay all or any portion of the outstanding Term Loan by simultaneously paying to Horizon an amount equal to (i) any accrued and unpaid interest on the outstanding principal balance of the Term Loan so prepaid; plus (ii) an amount equal to (A) if such Term Loan is prepaid on or before the Loan Amortization Date (as defined in the Loan and Security Agreement) applicable to such Term Loan, three percent of the then outstanding principal balance of such Term Loan, (B) if such Term Loan is prepaid after the Loan Amortization Date applicable to such Term Loan, but on or before the date that is 12 months after such Loan Amortization Date, two percent of the then outstanding principal balance of such Term Loan, or (C) if such Term Loan is prepaid more than 12) months after the Loan Amortization Date applicable to such Term Loan, one percent of the then outstanding principal balance of such Term Loan; plus (iii) the outstanding principal balance of such Term Loan; plus (iv) all other sums, if any, that had become due and payable under the Loan and Security Agreement.
Debt issuance costs incurred			$ 300
Proceeds from issuance of warrants			$ 326	$ 0
Applied interest rate			9.50%
Due on April 1 2025 [Member]
Debt Disclosure [Line Items]
Long-term line of credit			$ 5,000
Debt instrument, fee amount			200
Due on June-22-2025 [Member]
Debt Disclosure [Line Items]
Long-term line of credit			5,000
Debt instrument, fee amount			$ 200
Term Loan [Member]
Debt Disclosure [Line Items]
Number of loans | Loan		4
Long-term line of credit		$ 2,500
Proceeds from lines of credit	$ 5,000	$ 5,000

Term Debt - Summary of Debt (De

Term Debt - Summary of Debt (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Term debt	$ 10,000	$ 0
Less: Unamortized deferred issuance costs	(216)	0
Less: Warrant discount and interest	(249)	0
Term loan, long-term	9,535	0
Term Loan A and B due April 2025 [Member]
Debt Instrument [Line Items]
Term debt	5,000	0
Term Loan C and D due June 2025 [Member]
Debt Instrument [Line Items]
Term debt	$ 5,000	$ 0

Term Debt - Summary of Debt (Pa

Term Debt - Summary of Debt (Parenthetical) (Detail)	9 Months Ended
	Sep. 30, 2021
Term Loan A and B due April 2025 [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturity month year	2025-04
Term Loan C and D due June 2025 [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturity month year	2025-06

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail)	May 06, 2021USD ($)$ / sharesshares	Jan. 15, 2021d$ / sharesshares	Jun. 30, 2021USD ($)shares	Sep. 30, 2021USD ($)$ / sharesshares	Sep. 30, 2020USD ($)	Mar. 30, 2021USD ($)$ / shares	Dec. 31, 2020$ / sharesshares
Class of Stock [Line Items]
Exercise price | $ / shares		$ 9.47
Shares Exercised During the period | shares		42,236
Warrants outstanding | shares				42,236
Common stock, par value | $ / shares				$ 0.0001			$ 0.0001
Common stock, shares issued | shares				20,623,041			9,100,117
Gross proceeds from issuance of common stock				$ 9,115,000
Debt Conversion, Warrants issued to purchase of common shares				100,000
Debt instrument, convertible, threshold trading days | d		10
Net proceeds from issuance of common stock				$ 77,295,000	$ 0
SBPH Sales Agreement [Member]
Class of Stock [Line Items]
Common stock, par value | $ / shares	$ 0.0001					$ 0.0001
Common stock, shares issued | shares	979,843		979,843
Gross proceeds from issuance of common stock	$ 9,500,000		$ 9,500,000
Proceeds from initial public offer	10,400,000
Aggregate offering price						$ 50,000,000
Net proceeds from issuance of common stock	9,100,000		$ 9,200,000
SBPH Sales Agreement [Member] | IPO Warrants [Member]
Class of Stock [Line Items]
Gross proceeds from issuance of common stock	73,100,000
Issuance cost	4,400,000
Professional fees	500,000
Net proceeds from issuance of common stock	$ 68,200,000

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Warrant Activity (Detail) - Common Stock Warrants [Member]	9 Months Ended
	Sep. 30, 2021shares
Class of Warrant or Right [Line Items]
Outstanding, Beginning Balance	144,384
Exercises	(51,054)
Issued	42,236
Expired	(10,837)
Outstanding, Ending balance	124,729

Stock Option Plans - Summary of

Stock Option Plans - Summary of Stock Option Valuation (Detail)	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Risk free rate, Minimum	0.76%	0.17%
Risk free rate, Maximum	0.86%	0.42%
Expected volatility	92.90%
Expected volatility, Minimum		82.80%
Expected volatility, Maximum		98.30%
Expected dividend yield	0.00%	0.00%
Expected life (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) - USD ($) $ / shares in Units, $ in Thousands	Jan. 15, 2021	Sep. 30, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Exercised	(42,236)
Two Thousand And Nineteen Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Beginning Balance		533,559
Number of Shares, Granted		624,986
Number of Shares, Exercised		(19,805)
Number of Shares, Forfeited and expired		(55,550)
Number of Shares, Ending balance		1,083,190	533,559
Number of Shares, Exercisable		232,626
Weighted average exercise price, Options outstanding, Beginning Balance		$ 3.33
Weighted average exercise price, Granted		7.76
Weighted average exercise price, Exercised		0.12
Weighted average exercise price, Forfeited and expired		5.98
Weighted average exercise price, Options outstanding, Ending Balance		5.80	$ 3.33
Weighted average exercise price, Options exercisable		$ 5.86
Weighted average contractual term		8 years 11 months 23 days	9 years 3 months 18 days
Weighted average contractual term, Granted		8 years 11 months 26 days
Weighted average contractual term, Exercised		8 years 1 month 24 days
Weighted average contractual term, Forfeited and expired		9 years 4 months 17 days
Weighted average contractual term ,Exercisable		8 years 3 months 3 days
Intrinsic Value, Options outstanding		$ 6,011	$ 8,494
Intrinsic Value, Granted		(1,008)
Intrinsic Value, Exercised		500
Intrinsic Value, Forfeited and expired		157
Intrinsic Value, Option exercisable		$ 2,801

Stock Option Plans - Summary _3

Stock Option Plans - Summary of RSU Activity (Detail) - Performance-Based Restricted Stock Units [Member]	9 Months Ended
	Sep. 30, 2021$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested units, Beginning Balance | shares	69,749
Nonvested units, Granted | shares	310,385
Nonvested units, Vested | shares	(83,889)
Nonvested units, Ending Balance | shares	296,245
Weighted-Average Grant Date Fair Value Nonvested units, Beginning Balance | $ / shares	$ 11.73
Weighted-Average Grant Date Fair Value Granted | $ / shares	8.57
Weighted-Average Grant Date Fair Value Vested | $ / shares	9.34
Weighted-Average Grant Date Fair Value Nonvested units, Ending Balance | $ / shares	$ 9.10

Stock Option Plans - Summary _4

Stock Option Plans - Summary of Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 1,515	$ 1,194	$ 5,554	$ 2,199
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	1,115	1,135	4,197	1,682
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	$ 400	$ 59	$ 1,357	$ 517

Stock Option Plans - Additional

Stock Option Plans - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Feb. 28, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				4 years
Arrangement term				10 years
Number of shares remain available for grant		196,910		196,910
Stock-based compensation expense		$ 1,515	$ 1,194	$ 5,554	$ 2,199
Increase in total number of shares outstanding, percentage						4.00%
Time Based Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSUs issued	310,385
Weighted-Average Grant Date Fair Value Granted				$ 8.57
Stock-based compensation expense		400		$ 1,800
Maximum [member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage				28.00%
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage				25.00%
2019 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation expense		4,400		$ 4,400
Weighted-average remaining vesting period				2 years 8 months 12 days
2019 Equity Incentive Plan [Member] | Time Based Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation expense		$ 1,500		$ 1,500
Weighted-average remaining vesting period				3 years
2015 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average fair value of all stock options granted				$ 6.15	$ 1.65
Fair value of stock options vested				$ 4,200	$ 4,400

Significant Agreements - Summar

Significant Agreements - Summary of License and Collaboration Agreements (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Total collaboration revenues	$ 751	$ 9,195	$ 3,668	$ 11,093
Ares [Member]
Disaggregation of Revenue [Line Items]
Total collaboration revenues	0	8,691	2,800	9,945
Denali [Member]
Disaggregation of Revenue [Line Items]
Total collaboration revenues	0	504	117	1,148
AstraZeneca [Member]
Disaggregation of Revenue [Line Items]
Total collaboration revenues	500	0	500	0
Other [Member]
Disaggregation of Revenue [Line Items]
Total collaboration revenues	$ 251	$ 0	$ 251	$ 0

Significant Agreements - Summ_2

Significant Agreements - Summary of Contract Assets and Liabilities (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)
Contract With Customer Asset And Liability [Line Items]
Deferred revenue balance at January 1, 2021	$ 300
Additions	0
Revenue recognized	(154)
Impact of exchange rates	(146)
Deferred revenue balance at September 30, 2021	0
Ares [Member]
Contract With Customer Asset And Liability [Line Items]
Deferred revenue balance at January 1, 2021	37
Additions	0
Revenue recognized	(37)
Impact of exchange rates	0
Deferred revenue balance at September 30, 2021	0
Denali [Member]
Contract With Customer Asset And Liability [Line Items]
Deferred revenue balance at January 1, 2021	263
Additions	0
Revenue recognized	(117)
Impact of exchange rates	(146)
Deferred revenue balance at September 30, 2021	$ 0

Significant Agreements - Additi

Significant Agreements - Additional Information (Detail) - USD ($) $ in Thousands	Jul. 15, 2020	Mar. 31, 2021	Aug. 31, 2020	May 31, 2018	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2019	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Revenue from contract with customers revenue recognised under cost method					$ 751	$ 9,195	$ 3,668	$ 11,093
Denali Holding Limited [member]
Disaggregation of Revenue [Line Items]
Milestone payment receivable					49,500		49,500
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		7,100
Increase in the transaction price									$ 6,600
Performance obligation revenue recognized					0
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
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		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		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		2,100
Performance obligation revenue recognized						500	100	1,100
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		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		3,000
Ares Trading [member]
Disaggregation of Revenue [Line Items]
Option Payment Received		$ 2,700
Ares Trading [member] | License And Collaboration Agreement [member] | Delta [member]
Disaggregation of Revenue [Line Items]
Option Payment Received	$ 8,500								11,100
Ares Trading [member] | Amended And Restated License And Collaboration Agreement [member] | Delta [member]
Disaggregation of Revenue [Line Items]
Transaction price allocated									$ 15,400
Ares Trading [member] | Amended And Restated 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						$ 200		$ 1,500
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										$ 292,300
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										$ 473,900
Option fee receivable					2,700		2,700
AstraZeneca [Member] | License agreement [member]
Disaggregation of Revenue [Line Items]
Upfront Fee Received					500
Transaction price allocated					500		500
Performance obligation revenue recognized					500		$ 500
Percentage of net proceeds							80.00%
AstraZeneca [Member] | License agreement [member] | Development Milestone [member]
Disaggregation of Revenue [Line Items]
Milestone payment receivable					11,500		$ 11,500
AstraZeneca [Member] | License agreement [member] | Sales Based Milestone [member]
Disaggregation of Revenue [Line Items]
Milestone payment receivable					221,300		221,300
AstraZeneca [Member] | License agreement [member] | Development And Regulatory Milestone [member]
Disaggregation of Revenue [Line Items]
Milestone payment receivable					$ 96,500		$ 96,500

Commitments and Contingencies -

Commitments and Contingencies - Summary of Maturities of Operating Lease Liabilities (Detail) $ in Thousands	Sep. 30, 2021USD ($)
Commitments and Contingencies Disclosure [Abstract]
For the period October 1, 2021 to December 31, 2021	$ 242
2022	978
2023	990
2024	474
2025	486
Thereafter	1,444
Total lease payments	$ 4,614

Commitments and Contingencies_2

Commitments and Contingencies - Summary of Future Expected Cash Receipts From Subleases (Detail) $ in Thousands	Sep. 30, 2021USD ($)
Commitments and Contingencies Disclosure [Abstract]
For the period October 1, 2021 to December 31, 2021	$ 56
2022	462
2023	474
2024	486
2025	498
Thereafter	1,481
Total sublease receipts	$ 3,457

Commitments and Contingencies_3

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Jan. 27, 2021
Remaining operating lease term		2 years 3 months 18 days
Operating Lease, existence of option to extend	true
Operating lease costs	$ 0.8
Operating sublease income	0.4
Contractual Obligation	$ 2.6
Maximum [member]
Sublease term	7 years 1 month 6 days
Principal Office And Laboratory Space [Member]
Operating leases, weighted average remaining lease term	7 years 1 month 6 days
Operating leases, extendable lease term	5 years
Operating leases, option to extend lease	an option to extend the lease for up to five years.

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - Subsequent Event [Member] - License agreement with Janssen Biotech, Inc. [Member] $ in Millions	Oct. 19, 2021USD ($)
Subsequent Event [Line Items]
Upfront fee amount	$ 17.5
Development and Sales Milestone [Member]
Subsequent Event [Line Items]
Milestone payments	$ 1,350