Shattuck Labs (STTK) 10-K 15 Mar 22 2021 FY Annual report Financial data

COVER

COVER - USD ($)	12 Months Ended
	Dec. 31, 2021	Mar. 01, 2022	Jun. 30, 2021
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2021
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-39593
Entity Registrant Name	Shattuck Labs, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	81-2575858
Entity Address, Address Line One	500 W. 5th Street
Entity Address, Address Line Two	Suite 1200
Entity Address, City or Town	Austin
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	78701
City Area Code	512
Local Phone Number	900-4690
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Trading Symbol	STTK
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Public Float			$ 690,080,047
Entity Common Stock, Shares Outstanding		42,363,901
Documents Incorporated by Reference	Documents Incorporated by Reference The information required by Part III of this Report, to the extent not set forth herein, is incorporated by reference from the registrant’s definitive proxy statement relating to the Annual Meeting of Stockholders to be held in 2022, which shall be filed with the Securities and Exchange Commission within 120 days after the end of the fiscal year to which this Report relates.
Entity Central Index Key	0001680367
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY

Audit Information

Audit Information	12 Months Ended
	Dec. 31, 2021
Auditor Information [Abstract]
Auditor Name	KPMG LLP
Auditor Firm ID	185
Auditor Location	Austin, Texas

BALANCE SHEETS

BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 92,268	$ 157,898
Short-term investments	176,536	177,551
Prepaid expenses and other current assets	19,462	10,190
Total current assets	288,266	345,639
Property and equipment, net	9,938	3,000
Other assets	381	349
Total assets	298,585	348,988
Current liabilities:
Accounts payable	10,012	1,754
Accrued expenses	14,574	7,352
Deferred revenue - related party	0	7,728
Total current liabilities	24,586	16,834
Deferred rent	2,213	987
Deferred revenue - related party, net of current portion	0	21,306
Total liabilities	26,799	39,127
Commitments and contingencies (Note 6)
Stockholders’ equity:
Common stock; $0.0001 par value: 300,000,000 shares authorized, 42,338,898 shares issued and outstanding at December 31, 2021 and 41,779,183 shares issued and 41,767,431 shares outstanding at December 31, 2020	5	5
Additional paid-in capital	389,408	382,012
Accumulated other comprehensive loss	(560)	(63)
Accumulated deficit	(117,067)	(72,093)
Total stockholders’ equity	271,786	309,861
Total liabilities and stockholders’ equity	$ 298,585	$ 348,988

BALANCE SHEETS - Parenthetical

BALANCE SHEETS - Parenthetical - $ / shares	Dec. 31, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	300,000,000	300,000,000
Common stock, shares issued (in shares)	42,338,898	41,779,183
Common stock, shares outstanding (in shares)	42,338,898	41,767,431

STATEMENTS OF OPERATIONS AND CO

STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Statement [Abstract]
Revenue from Contract with Customer, Product and Service [Extensible List]	License [Member]	License [Member]
Collaboration revenue - related party	$ 30,017	$ 9,934
Operating expenses:
Research and development	56,563	37,483
General and administrative	18,723	9,382
Expense from operations	75,286	46,865
Loss from operations	(45,269)	(36,931)
Other income (expense):
Interest income	625	549
Other	(330)	(221)
Total other income (expense)	295	328
Net loss	(44,974)	(36,603)
Unrealized loss on investments	(497)	(117)
Comprehensive loss	$ (45,471)	$ (36,720)
Net loss per share – basic (in dollars per share)	$ (1.07)	$ (2.36)
Net loss per share – diluted (in dollars per share)	$ (1.07)	$ (2.36)
Weighted-average shares outstanding - basic (in shares)	42,032,384	15,506,067
Weighted-average shares outstanding - diluted (in shares)	42,032,384	15,506,067

STATEMENT OF CHANGES IN REDEEMA

STATEMENT OF CHANGES IN REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS’ EQUITY (DEFICIT) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Series A Redeemable Convertible Preferred Stock	Series A Redeemable Convertible Preferred StockCommon Stock	Series A Redeemable Convertible Preferred StockAdditional Paid-In Capital	Series B Redeemable Convertible Preferred Stock	Series B Redeemable Convertible Preferred StockCommon Stock	Series B Redeemable Convertible Preferred StockAdditional Paid-In Capital	Series B-1 Redeemable Convertible Preferred Stock	Series B-1 Redeemable Convertible Preferred StockCommon Stock	Series B-1 Redeemable Convertible Preferred StockAdditional Paid-In Capital
Preferred stock, beginning balance (in shares) at Dec. 31, 2019						1,093,019			0			0
Preferred stock, beginning balance at Dec. 31, 2019						$ 49,064			$ 0			$ 0
Increase (Decrease) in Temporary Equity [Roll Forward]
Sale of redeemable convertible preferred stock, net of issuance costs (in shares)									550,571,000			1,319,964
Sale of redeemable convertible preferred stock, net of issuance costs									$ 34,427			$ 82,613
Conversion of redeemable convertible preferred stock (in shares)						(1,093,019)			(550,571,000)			(1,319,964)
Conversion of redeemable convertible preferred stock						$ (49,064)			$ (34,427)			$ (82,613)
Preferred stock, ending balance (in shares) at Dec. 31, 2020						0			0			0
Preferred stock, ending balance at Dec. 31, 2020						$ 0			$ 0			$ 0
Beginning balance (in shares) at Dec. 31, 2019		7,600,877
Beginning balance at Dec. 31, 2019	$ (34,548)	$ 1	$ 887	$ 54	$ (35,490)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of redeemable convertible preferred stock (in shares)							7,487,151			3,771,363			9,041,739
Conversion of redeemable convertible preferred stock						$ 49,064	$ 1	$ 49,063	$ 34,427	$ 1	$ 34,426	$ 82,613	$ 1	$ 82,612
Issuance of common stock upon initial public offering, net of issuance cost (in shares)		13,664,704
Issuance of common stock upon initial public offering, net of issuance cost	213,530	$ 1	213,529
Exercise of stock options (in shares)		181,449
Exercise of stock options	229	$ 0	229
Vesting of common stock previously subject to vesting (in shares)		20,148
Stock-based compensation expense	1,266		1,266
Unrealized loss on investments	(117)			(117)
Net loss	(36,603)				(36,603)
Ending balance (in shares) at Dec. 31, 2020		41,767,431
Ending balance at Dec. 31, 2020	$ 309,861	$ 5	382,012	(63)	(72,093)
Preferred stock, ending balance (in shares) at Dec. 31, 2021						0			0			0
Preferred stock, ending balance at Dec. 31, 2021						$ 0			$ 0			$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)	557,609
Vesting of common stock previously subject to vesting (in shares)		11,752
Stock-based compensation expense	$ 5,467		5,467
Unrealized loss on investments	(497)			(497)
Net loss	(44,974)				(44,974)
Exercise of stock options and ESPP purchases (in shares)		559,715
Exercise of stock options and ESPP purchases	1,929		1,929
Ending balance (in shares) at Dec. 31, 2021		42,338,898
Ending balance at Dec. 31, 2021	$ 271,786	$ 5	$ 389,408	$ (560)	$ (117,067)

STATEMENTS OF CASH FLOWS

STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operations:
Net loss	$ (44,974)	$ (36,603)
Adjustments to reconcile net loss to net cash used in operations:
Stock-based compensation	5,467	1,266
Depreciation	1,380	618
Net amortization of premium on short-term investments	3,035	1
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(9,272)	(6,835)
Other assets	(32)	(326)
Accounts payable	7,866	(1,751)
Accrued expenses	6,924	3,313
Deferred revenue - related party	(29,034)	6,569
Deferred rent	1,524	89
Net cash used in operating activities	(57,116)	(33,659)
Cash flows from investing activities:
Purchase of property and equipment	(7,926)	(727)
Sale and maturities of short-term investments	201,575	37,595
Purchases of short-term investments	(204,092)	(183,190)
Net cash used in investing activities	(10,443)	(146,322)
Cash flows from financing activities:
Proceeds from the exercises of stock options and ESPP purchases	1,929	229
Proceeds from the initial public offering	0	232,301
Net cash provided by financing activities	1,929	330,866
Net increase (decrease) in cash and cash equivalents	(65,630)	150,885
Cash and cash equivalents, beginning of period	157,898	7,013
Cash and cash equivalents, end of period	92,268	157,898
Supplemental disclosures of non-cash financial activities:
Unrealized loss on short-term investments	(497)	(117)
Unpaid amounts related to purchase of property and equipment	392	454
IPO
Cash flows from financing activities:
Issuance costs	0	(18,738)
Series B-1 Redeemable Convertible Preferred Stock
Cash flows from financing activities:
Issuance costs	0	(387)
Proceeds from sale of redeemable convertible preferred stock, net of issuance costs	0	83,000
Series B Redeemable Convertible Preferred Stock
Cash flows from financing activities:
Issuance costs	0	(159)
Proceeds from sale of redeemable convertible preferred stock, net of issuance costs	$ 0	$ 34,620

Organization and Description of

Organization and Description of Business	12 Months Ended
	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	Organization and Description of Business Shattuck Labs, Inc. (the “Company”) was incorporated in 2016 in the State of Delaware and is a clinical-stage biopharmaceutical company developing dual-sided fusion proteins, including its ARC ® and GADLEN ™ platforms, as novel classes of biologic medicines capable of multifunctional activity with potential applications in oncology and inflammatory diseases. Using its proprietary technology, the Company is building a pipeline of therapeutics, initially focused on the treatment of solid tumors and hematologic malignancies. The Company has two clinical-stage product candidates, SL-172154 and SL-279252, and has several compounds in preclinical development. Liquidity The Company has incurred losses and negative cash flows from operations since inception and has an accumulated deficit of $117.1 million as of December 31, 2021. The Company anticipates incurring additional losses and negative cash flows from operations until such time, if ever, that it can generate significant sales of its product candidates currently in development, and is highly dependent on its ability to find additional sources of funding in the form of licensing of its technology, collaboration agreements, and/or public and private debt and equity financings. Adequate additional funding may not be available to the Company on acceptable terms, or at all. The failure to raise funds as and when needed could have a negative impact on the Company’s financial condition and ability to pursue its clinical operations, research and development and commercialization of its product candidates. Management believes that the Company’s cash and cash equivalents and short-term investments of $268.8 million as of December 31, 2021, are sufficient to fund projected operations of the Company for at least the next twelve months. COVID-19 Pandemic On March 10, 2020, the World Health Organization declared the COVID-19 outbreak a pandemic. The virus and actions taken to mitigate its spread have had, and are expected to continue to have, a broad adverse impact on the economies and financial markets of many countries, including the geographical areas in which the Company operates and conducts its business and in which the Company’s partners operate and conduct their business. The Company is currently following the recommendations of local health authorities to minimize exposure risk for its team members and visitors. However, the scale and scope of this pandemic is unknown and the duration of the business disruption and related financial impact cannot be reasonably estimated at this time. While the Company has implemented specific business continuity plans to reduce the potential impact of COVID-19, there is no guarantee that the Company’s continuity plans will be successful. The Company has already experienced disruptions to its business such as work-from-home orders for offices and similar disruptions have occurred for its partners. Specifically, the outbreak has caused disruptions in its ability to manufacture clinical trial materials, including the acquisition of raw materials needed for such manufacturing, enrollment and treatment of patients in clinical trials in process, and slowdowns and shutdowns of the laboratories and other service providers that are being relied upon in the development of the Company’s product candidates. The extent to which the COVID-19 pandemic or any other health epidemic may impact the Company’s results will depend on future developments, which are highly uncertain and cannot be predicted, including new information that may emerge concerning the severity of COVID-19 and the actions to mitigate its impact, among others. Accordingly, the COVID-19 pandemic could have a material adverse effect on the Company’s business, results of operations and financial condition.

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	Basis of Presentation and Summary of Significant Accounting Policies Basis of Presentation The accompanying audited financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Significant estimates and assumptions reflected in these financial statements include, but are not limited to, revenue recognition, the accrual of research and development expenses, and the valuation of stock-based awards. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Changes in estimates, if any, are recorded in the period in which they become known and actual results could differ from management’s estimates. A change in the Company’s estimates occurred in the second quarter of 2021, which impacted the Company’s revenue recognition and related balance sheet accounts. Fair Value of Financial Instruments Fair value is defined as the price that would be received upon the sale of an asset or paid upon the transfer of a liability in an orderly transaction between market participants at the measurement date and in the principal or most advantageous market for that asset or liability. Fair value measurements are classified and disclosed in one of the following categories: • Level 1: Observable inputs such as quoted prices in active markets for identical assets the reporting entity has the ability to access as of the measurement date; • Level 2: Inputs, other than quoted prices in active markets, that are observable either directly or indirectly; and • Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. Fair value measurements are classified based on the lowest level of input that is significant to the measurement. The Company’s assessment of the significance of a particular input to the fair value measurement requires judgment, which may affect the valuation of the assets and liabilities and their placement within the fair value hierarchy levels. The determination of the fair values stated below takes into account the market for its financial assets and liabilities, the associated credit risk and other factors as required. The Company considers active markets as those in which transactions for the assets or liabilities occur with sufficient frequency and volume to provide pricing information on an ongoing basis. Management believes that the carrying amounts of the Company’s financial instruments, including short-term investments and accounts payable, approximate fair value due to the short-term nature of those instruments. Concentration of Risk Financial instruments that potentially subject the Company to concentrations of credit risk primarily consist of cash, cash equivalents and short-term investments. The Company maintains its cash and cash equivalents at two accredited financial institutions in amounts that exceed federally-insured limits. The Company does not believe that it is subject to unusual credit risk beyond the normal credit risk associated with commercial banking relationships. The Company invests in only highly rated debt securities that management believes protects the Company from risk of default and impairment of value. All of the Company’s revenue is derived from its collaboration agreement with Millennium Pharmaceuticals, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited (“Takeda”), which was mutually terminated pursuant to the termination agreement, dated November 8, 2021. The Company is highly dependent on one third-party contract manufacturing organization (“CMO”) to supply drug products for its research and development activities of its programs, including clinical trials and non-clinical studies. These programs could be adversely affected by a significant interruption in the supply of such drug products. The Company is highly dependent on three contract research organizations (“CROs”) and a limited number of third-party service providers to manage and support its clinical trials. These programs could be adversely affected by a significant disruption in services provided by these CROs and third parties. Cash and Cash Equivalents The Company considers all demand deposits with financial institutions and all highly liquid investments with original maturities of 90 days or less at the date of purchase to be cash and cash equivalents. Cash and cash equivalents consisted of $14.6 million held in operating accounts and $77.7 million held in money market funds as of December 31, 2021 and $2.7 million held in operating accounts, $80.2 million held in money market funds and $75.0 million held in government obligations as of December 31, 2020. Short-Term Investments Short-term investments consist of highly-rated U.S. Treasury securities with maturities of more than three months but less than one year at the date of purchase. The Company classifies its short-term investments at the time of purchase as available-for-sale securities. Available-for-sale securities are carried at fair value. Credit impairments for available-for-sale debt securities are recorded through an allowance rather than a direct write-down of the security and are recorded through a charge to the statements of operations. Unrealized gains or losses not related to credit impairments are recorded in accumulated other comprehensive income, a component of stockholders’ equity, until realized. The Company reviews available-for-sale debt securities for impairments related to credit losses and other factors each quarter. As of December 31, 2021, there were no impairments related to credit losses of short-term investments. Deferred Offering Costs The Company capitalizes certain legal, accounting and other third-party fees that are directly associated with in-process equity financings as deferred offering costs until such financings are consummated. After consummation of the equity financing, these costs will be recorded against gross proceeds. Series A, Series B and Series B-1 Redeemable Convertible Preferred Stock The Company records shares of redeemable convertible preferred stock at their respective fair values on the date of issuance, net of issuance costs. The redeemable convertible preferred stock is recorded outside of stockholders’ equity on the balance sheet because the shares contain liquidation features that are not solely within the Company’s control. Upon the completion of the Company’s initial public offering (“IPO”) in the fourth quarter of 2020, all outstanding shares of the Company’s redeemable convertible preferred stock were converted into common stock. Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets include prepaid expenses for general business purposes and services used in research projects, which are stated at cost and amortized on a straight-line basis over the related period of benefit. Supplies and materials that have multiple applications for alternative future use are expensed as they are consumed. Property and Equipment Property and equipment are stated at cost, net of accumulated depreciation. Depreciation expense is recognized using the straight-line method over the estimated useful life of the asset. Expenditures for repairs and maintenance that do not extend the estimated useful life or improve an asset are expensed as incurred. Upon retirement or sale, the cost and related accumulated depreciation and amortization of assets disposed of are removed from the accounts, and any resulting gain or loss is included in the statement of operations and comprehensive loss. Depreciation periods are as follows: Office equipment 3 years Furniture and fixtures 5 to 10 years Lab equipment 5 years Leasehold improvements Shorter of lease term or 15 years Impairment of Long-Lived Assets Long-lived assets are reviewed for indications of possible impairment whenever events or changes in circumstance indicate that the carrying amount of an asset may not be recoverable. Recoverability is measured by comparison of the carrying amounts to the future undiscounted cash flows attributable to these assets. An impairment loss is recognized to the extent an asset group is not recoverable and the carrying amount exceeds the projected discounted future cash flows arising from these assets. There were no impairments of long-lived assets for the years ended December 31, 2021 and 2020. Deferred Rent The Company records rent expense on a straight-line basis over the term of the leases and, accordingly records the difference between cash payments and the recognition of rent expense as a deferred rent asset or liability. Incentives granted under the Company’s leases, including allowances to fund leasehold improvements, are deferred and recognized as adjustments to rent expense on a straight-line basis over the term of the leases. Revenue Recognition Collaboration revenue is recognized in accordance with ASC 606, Revenue from Contracts with Customers (“ASC 606”). Arrangements with collaborators may include licenses to intellectual property, research and development services, manufacturing services for clinical and commercial supply and participation on joint steering committees. The Company evaluates the promised goods or services in the contract to determine which promises, or group of promises, represent performance obligations. In contemplation of whether a promised good or service meets the criteria required of a performance obligation, the Company considers the stage of development of the underlying intellectual property, the capabilities and expertise of the customer relative to the underlying intellectual property and whether the promised goods or services are integral to or dependent on other promises in the contract. When accounting for an arrangement that contains multiple performance obligations, the Company must develop judgmental assumptions, which may include market conditions, reimbursement rates for personnel costs, development timelines and probabilities of regulatory success to determine the stand-alone selling price for each performance obligation identified in the contract. Upon the amendment of an existing agreement, the Company evaluates whether the amendment represents a modification to an existing contract which would be recorded through a cumulative catch-up to revenue, or a separate contract. If it is determined that it is a separate contract, the Company will evaluate the necessary revenue recognition through the five-step process described below. When the Company concludes that a contract should be accounted for as a combined performance obligation and recognized over time, the Company must then determine the period over which revenue should be recognized and the method by which to measure revenue. The Company generally recognizes revenue using a cost-based input method. The Company recognizes collaboration revenue in an amount that reflects the consideration that the Company expects to receive in exchange for those goods or services when its customer or collaborator obtains control of promised goods or services. To determine revenue recognition for arrangements that the Company determines are within the scope of ASC 606, the following five steps are performed: i. identify the contract(s) with a customer; ii. identify the performance obligations in the contract; iii. determine the transaction price; iv. allocate the transaction price to the performance obligations within the contract; and v. recognize revenue when (or as) the entity satisfies a performance obligation. The Company only applies the five-step model to contracts when it determines that it is probable it will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, once the contract is determined to be within the scope of ASC 606, the Company assesses the goods or services promised within the contract to determine whether each promised good or service is a performance obligation. The promised goods or services in the Company’s arrangements may consist of a license of, or options to license, the Company’s intellectual property and research, development and manufacturing services. The Company may provide options to additional items in such arrangements, which are accounted for as separate contracts when the customer elects to exercise such options, unless the option provides a material right to the customer. Performance obligations are promises in a contract to transfer a distinct good or service to the customer that (i) the customer can benefit from on its own or together with other readily available resources and (ii) are separately identifiable from other promises in the contract. Goods or services that are not individually distinct performance obligations are combined with other promised goods or services until such combined group of promises meet the requirements of a performance obligation. The Company determines transaction price based on the amount of consideration the Company expects to receive for transferring the promised goods or services in the contract. Consideration may be fixed, variable or a combination of both. At contract inception for arrangements that include variable consideration, the Company estimates the probability and extent of consideration it expects to receive under the contract utilizing either the most-likely amount method or expected amount method, whichever best estimates the amount expected to be received. The Company then considers any constraints on the variable consideration and includes variable consideration in the transaction price to the extent it is deemed probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. The Company then allocates the transaction price to each performance obligation based on the relative standalone selling price and recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) control is transferred to the customer and the performance obligation is satisfied. For performance obligations which consist of licenses and other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. The Company records amounts as accounts receivable when the right to consideration is deemed unconditional. When consideration is received, or such consideration is unconditionally due, from a customer prior to transferring goods or services to the customer under the terms of a contract, a contract liability is recorded as deferred revenue. Amounts received prior to satisfying the revenue recognition criteria are recognized as deferred revenue in the Company’s accompanying balance sheet. Deferred revenues expected to be recognized as revenue within the 12 months following the balance sheet date are classified as a current liability. Deferred revenues not expected to be recognized as revenue within the 12 months following the balance sheet date are classified as non-current liabilities. The Company’s collaboration revenue arrangements may include the following: Up-front License Fees: If a license is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenues from nonrefundable, up-front fees allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, up-front fees. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. Milestone Payments: At the inception of an agreement that includes research and development milestone payments, the Company evaluates each milestone to determine when and how much of the milestone to include in the transaction price. The Company first estimates the amount of the milestone payment that the Company could receive using either the expected value or the most-likely amount approach. The Company primarily uses the most-likely amount approach as that approach is generally most predictive for milestone payments with a binary outcome. The Company then considers whether any portion of that estimated amount is subject to the variable consideration constraint (that is, whether it is probable that a significant reversal of cumulative revenue would not occur upon resolution of the uncertainty). The Company updates the estimate of variable consideration included in the transaction price at each reporting date which includes updating the assessment of the likely amount of consideration and the application of the constraint to reflect current facts and circumstances. Royalties: For arrangements that include sales-based royalties, including milestone payments based on a level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company will recognize revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). To date, the Company has not granted a development and commercialization license nor recognized any revenue related to sales-based royalties or milestone payments based on the level of sales. Research and Development Services: The Company will record costs associated with development and process optimization activities as research and development expenses in the statements of operations and comprehensive loss consistent with ASC 730, Research and Development. The Company considered the guidance in ASC 808, Collaborative Agreements and will recognize the payments received from these agreements as revenue when the related costs are incurred. Research and Development Costs Research and development costs are expensed as incurred, and include salaries, stock-based compensation and other personnel-related costs, equipment and supplies, depreciation, nonclinical studies, clinical trials and manufacturing development activities. A substantial portion of the Company’s ongoing research and development activities are conducted by third-party service providers, including CROs and CMOs. The Company accrues for expenses resulting from obligations under agreements with CROs, CMOs and other outside service providers for which payment flows do not match the periods over which materials or services are provided to the Company. Accruals are recorded based on estimates of services received and efforts expended pursuant to agreements established with CROs, CMOs and other outside service providers. These estimates are typically based on contracted amounts applied to the proportion of work performed and determined through an evaluation of the progress or stage of completion of the services. In the event advance payments are made to a CRO, CMO or outside service provider, the payments will be recorded as a prepaid asset which will be amortized as the contracted services are performed. As actual costs become known, the Company adjusts its accruals and prepaid assets accordingly. Inputs, such as the services performed, the number of patients enrolled or the study duration, may vary from the Company’s estimates, resulting in adjustments to research and development expense in future periods. The Company makes significant judgements and estimates in determining the accrual and/or prepaid balance in each reporting period and changes in these estimates may result in material changes to the Company’s accruals that could materially affect the Company’s results of operations. Stock-Based Compensation The Company recognizes the grant-date fair value of stock-based awards issued to employees and nonemployee Board members as compensation expense on a straight-line basis over the vesting period of the award. The Company uses the Black-Scholes option pricing model to determine the grant-date fair value of stock options. The Company adjusts expense for forfeitures in the periods they occur. Income Taxes The Company uses the asset and liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the financial statements and the tax bases of assets and liabilities. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect of a change in tax rates on deferred tax assets and liabilities will be recognized in the period that includes the enactment date. Additionally, any changes in income tax laws are immediately recognized in the year of enactment. A valuation allowance is established against the deferred tax assets to reduce their carrying value to an amount that is more likely than not to be realized. The deferred tax assets and liabilities are classified as noncurrent along with the related valuation allowance. Due to a lack of earnings history, the net deferred tax assets have been fully offset by a valuation allowance. The Company recognizes benefits of uncertain tax positions if it is more likely than not that such positions will be sustained upon examination based solely on the technical merits, as the largest amount of benefits that is more likely than not to be realized upon the ultimate settlement. The Company’s policy is to recognize interest and penalties related to the unrecognized tax benefits as a component of income tax expense. Net Loss Per Share Basic loss per share of common stock is computed by dividing net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding during each period. Diluted loss per share of common stock includes the effect, if any, from the potential exercise or conversion of securities, such as redeemable convertible preferred stock, convertible notes, stock options and unvested shares of restricted stock, which would result in the issuance of incremental shares of common stock. For diluted net loss per share, the weighted-average number of shares of common stock is the same for basic net loss per share due to the fact that when a net loss exists, dilutive securities are not included in the calculation as the impact is anti-dilutive. The following potentially dilutive securities have been excluded from the computation of diluted weighted-average shares of common stock outstanding, as they would be anti-dilutive: December 31, 2021 2020 Stock options 2,448,676 2,742,022 Unvested restricted stock — 11,752 2,448,676 2,753,774 Other Comprehensive Income (Loss) Other comprehensive income (loss) is defined as the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. Other comprehensive income (loss) is comprised of the net loss and unrealized gains and losses on short-term investments. Recently Adopted Accounting Pronouncements In December 2019, the Financial Accounting Standards Board (the “FASB”) issued ASU No. 2019-12, Income Taxes: Simplifying the Accounting for Income Taxes . The ASU removes certain exceptions to the general principles in ASC 740, Income Taxes and also clarifies and amends existing guidance to improve consistent application. This ASU is effective for fiscal years beginning after December 15, 2020, including interim periods within that fiscal year, with early adoption permitted. The Company adopted this pronouncement effective January 1, 2021 and it did not have a material impact on the financial statements or related disclosures. Recently Issued Accounting Pronouncements (not yet adopted) In February 2016, the FASB issued ASU No. 2016-02, Leases which requires a lessee to record a right-of-use asset and a corresponding lease liability on the balance sheet for all leases with terms longer than 12 months. A modified retrospective

Short-Term Investments

Short-Term Investments	12 Months Ended
	Dec. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Short-Term Investments	Short-Term Investments The following table represents the Company’s available for sale short-term investments by major security type (amounts in thousands): December 31, 2021 Amortized Cost Gross Unrealized Loss Total Fair Value Short-term investments: U.S. government securities $ 177,096 $ (560) $ 176,536 Total short-term investments $ 177,096 $ (560) $ 176,536 December 31, 2020 Amortized Cost Gross Unrealized Loss Total Fair Value Short-term investments: U.S. government securities $ 177,614 $ (63) $ 177,551 Total short-term investments $ 177,614 $ (63) $ 177,551 The Company’s short-term investment instruments and cash and cash equivalents are classified using Level 1 inputs within the fair value hierarchy and are valued using quoted market prices, broker or dealer quotations, or alternative pricing sources with reasonable levels of price transparency. Debt securities have an average maturity of 0.43 years as of December 31, 2021.

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2021
Property, Plant and Equipment [Abstract]
Property and Equipment	Property and Equipment Property and equipment consisted of the following (amounts in thousands): December 31, 2021 2020 Lab equipment $ 5,823 $ 2,790 Leasehold improvements 3,709 1,073 Construction in progress 2,521 355 Furniture and fixtures 459 157 Office equipment 206 105 12,718 4,480 Accumulated depreciation and amortization (2,780) (1,480) Property and equipment, net $ 9,938 $ 3,000 Depreciation and amortization expense for the years ended December 31, 2021 and 2020 was $1.4 million and $0.6 million, respectively.

Accrued Expenses

Accrued Expenses	12 Months Ended
	Dec. 31, 2021
Payables and Accruals [Abstract]
Accrued Expenses	Accrued ExpensesAccrued expenses consisted of the following (amounts in thousands): December 31, 2021 2020 Research and development contract costs $ 10,253 $ 5,382 Compensation and related benefits 3,320 1,551 Other 1,001 419 Total accrued expenses $ 14,574 $ 7,352

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Operating Leases As of December 31, 2021, future minimum payments, by year and in aggregate, under non-cancelable operating leases consist of the following (amounts in thousands): 2022 $ 1,058 2023 1,089 2024 1,120 2025 1,152 2026 1,093 Thereafter 1,721 Total minimum lease payments $ 7,233 The Company recognized rent expense of $0.7 million and $0.4 million for the years ended December 31, 2021 and 2020, respectively. Heat License Agreement In connection with a license agreement with Heat Biologics Inc. (“Heat”), the Company is required to make payments of up to $20.6 million in aggregate for the achievement of specified development, regulatory and commercial sales milestones for certain licensed products. The Company is required to pay Heat a percentage of upfront fees or other non-royalty payments not tied to milestone events that it receives in connection with certain sublicenses of the licensed patents. The Company is also required to pay Heat a royalty on all of its worldwide net sales, those of its affiliates and sublicenses of certain licensed patents in the low single digits. The Company has not recorded a liability for the payments aforementioned given the achievement of specified development, regulatory and commercial sales milestones for certain licensed products is not probable as of the balance sheet date. Litigation From time to time, the Company may become involved in various legal actions arising in the ordinary course of business. On January 31, 2022 and February 11, 2022, putative class action lawsuits were filed in the U.S. District Court for the Eastern District of New York against us and certain of the Company’s officers and directors. In each complaint, the plaintiff cites the volatility in the Company’s common stock and alleges that the defendants made or are responsible for false or misleading statements regarding the Company’s collaboration agreement with Takeda. The plaintiffs in both lawsuits seek a ruling that the case may proceed as a class action, and seeks unspecified damages and attorneys’ fees, expert fees and costs. The Company and the individual defendants deny any allegations of wrongdoing and intend to vigorously defend against these lawsuits. Contractual Obligations

Preferred Stock

Preferred Stock	12 Months Ended
	Dec. 31, 2021
Temporary Equity Disclosure [Abstract]
Preferred Stock	Preferred StockDuring the year ended December 31, 2020, the Company entered into various stock purchase agreements with new and existing investors pursuant to which the Company sold an aggregate 550,571 shares of Series B redeemable convertible preferred stock and 1,319,964 shares of Series B-1 redeemable convertible preferred stock at $62.88051 per share for net proceeds of $117.0 million.The Company’s Series A, Series B and Series B-1 redeemable convertible preferred stock converted into common stock upon the completion of the Company’s IPO in 2020 and the rights, preferences, and terms are no longer applicable

Collaboration Agreement - Relat

Collaboration Agreement - Related Party	12 Months Ended
	Dec. 31, 2021
Related Party Transactions [Abstract]
Collaboration Agreement - Related Party	Collaboration Agreement - Related PartyThe Company recognized revenue for the allocated up-front payments using a cost-based input measure. In applying the cost-based input method of revenue recognition, the Company used actual costs incurred relative to budgeted costs expected to be incurred for the combined performance obligation. In August 2017, the Company entered into a Collaboration Agreement with Takeda related to the development of certain ARC molecules, as amended in April 2018, October 2018 and March 2020 (the “Collaboration Agreement”). The Collaboration Agreement was mutually terminated pursuant to a termination agreement dated November 8, 2021 (the “Termination Agreement”). Under the terms of the Termination Agreement, the Company is not required to satisfy any remaining performance obligations, the Company will not make any payments to or receive any future milestone or royalty payments from Takeda, and all options to license and rights of first negotiation held by Takeda under the Collaboration Agreement were terminated. The remaining deferred revenue was recognized as revenue in the fourth quarter of 2021. The Company received cash of $3.6 million and $14.0 million in the years ended December 31, 2021 and 2020, respectively, and recognized total revenue of $82.0 million through December 31, 2021 under the Collaboration Agreement.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2021
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation 2020 Equity Incentive Plan In September 2020, the Company adopted the 2020 Stock Incentive Plan (the “2020 Plan”) which, as of the adoption date, replaced the 2016 Stock Incentive Plan. Under the 2020 Plan, the share reserve automatically increases on January 1st of each year beginning in 2021 and ending with a final increase on January 1, 2030 in an amount equal to 4% of the Company’s outstanding common shares on December 31st of the preceding calendar year. The Board of Directors may provide that there will be no increase in the share reserve for any such year or that the increase in the share reserve may be smaller than would otherwise occur. As of December 31, 2021, there were 3,912,408 shares available for future grants under the 2020 Plan and on January 1, 2022, the share reserve automatically increased by 1,693,555 shares. The 2020 Plan permits the granting of options and restricted stock. The terms of the agreements under the 2020 Plan are determined by the Company’s Board of Directors. The Company’s awards vest based on the terms in the agreements and generally vest over four years and have a term of 10 years. 2020 Employee Stock Purchase Plan The 2020 Employee Stock Purchase Plan (“2020 ESPP”) became effective in connection with the Company’s IPO. A total of 395,795 shares of common stock were reserved for issuance under the 2020 ESPP. Eligible employees may purchase shares of common stock under the 2020 ESPP at 85% of the lower of the fair market value of the Company’s common stock as of the first or the last day of each offering period. Employees are limited to contributing 15% of the employee’s eligible compensation and may not purchase more than $25,000 of stock during any calendar year or more than 600 shares during any one purchase period. The 2020 ESPP share reserve automatically increases on January 1st of each calendar year, for ten years, commencing on January 1, 2021, in an amount equal to 1% of the total number of shares of common stock outstanding on December 31st of the preceding calendar year. The Board may act prior to January 1st of a given year to provide that there will be no January 1st increase of the share reserve for such year or that the increase in the share reserve for such year will be a smaller number of shares of common stock than would otherwise occur pursuant to the preceding sentence. As of December 31, 2021 there were 393,689 shares available for future purchases and on January 1, 2022, the share reserve automatically increased by 423,388 shares. Under the 2020 ESPP, the Company issued 2,106 shares of common stock for aggregate cash proceeds of $0.1 million during the year ended December 31, 2021. There were no shares of common stock issued during the year ended December 31, 2020. The Company recorded stock-based compensation expense in the following expense categories of its accompanying audited statements of operations and comprehensive loss (amounts in thousands): Year Ended December 31, 2021 2020 Research and development $ 2,200 $ 531 General and administrative 3,267 735 Total stock-based compensation $ 5,467 $ 1,266 The following table summarizes option activity under the 2020 Plan and the 2016 Stock Incentive Plan: Options Weighted Average Exercise Price Weighted Average Remaining Life (Years) Balance at January 1, 2021 2,742,022 $ 7.95 8.82 Granted 325,671 23.60 Exercised (557,609) 3.40 Forfeited (61,408) 12.13 Balance at December 31, 2021 2,448,676 $ 10.96 8.08 Vested and expected to vest 2,418,923 $ 10.88 8.07 Exercisable at the end of the period 1,259,440 $ 6.44 7.55 Options granted during the years ended December 31, 2021 and 2020 had weighted-average grant-date fair values of $16.38 and $8.93 per share, respectively. As of December 31, 2021, the unrecognized compensation cost was $11.4 million and will be recognized over an estimated weighted-average amortization period of 2.48 years. The aggregate intrinsic value of options exercised as of December 31, 2021 and 2020 was $10.8 million and $49.7 million, respectively. The aggregate intrinsic value of options outstanding and exercisable as of December 31, 2021 was $5.9 million. The fair value of each option is estimated on the date of grant using a Black-Scholes option pricing model which takes into account inputs such as the exercise price, the estimated fair value of the underlying common stock at grant date, expected term, expected stock price volatility, risk-free interest rate and dividend yield. The fair value of stock options was determined using the methods and assumptions discussed below. • The expected term of employee stock options with service-based vesting is determined using the “simplified” method, whereby the expected life equals the arithmetic average of the vesting term and the original contractual term of the option due to the Company’s lack of sufficient historical data. • The expected stock price volatility is based on historical volatilities of comparable public entities within the Company’s industry. • The risk-free interest rate is based on the interest rate payable on U.S. Treasury securities in effect at the time of grant for a period that is commensurate with the expected term. • The expected dividend yield is 0% because the Company has not historically paid, and does not expect, for the foreseeable future, to pay a dividend on its common stock. • Prior to the Company’s IPO, its Board periodically estimated the fair value of the Company’s common stock considering, among other things, contemporaneous valuations of its common stock prepared by an unrelated third-party valuation firm. Subsequent to the Company’s IPO, options are issued with a strike price no less than the market price on date of grant. The grant-date fair value of options granted under the Company’s 2020 Plan were estimated throughout the year using the Black-Scholes option-pricing model using the following weighted-average assumptions: Year Ended December 31, 2021 2020 Expected term - years 6.08 5.94 Expected volatility 81.4 % 75.3 % Risk-free interest rate 1.1 % 0.5 % Expected dividends — — The restricted shares are considered the issuance of share-based payments as opposed to the sale of stock and as such, the Company has recognized compensation expense for these awards based on the fair value of the award on the date of grant. The following table summarizes the activity relating to these shares: Awards Outstanding at December 31, 2020 11,752 Vested (11,752) Outstanding at December 31, 2021 — The grant-date fair value of shares issued under the Company’s 2020 ESPP were estimated throughout the year using the Black-Scholes option-pricing model using the following weighted-average assumptions: Year Ended December 31, 2021 2020 Expected term - years 0.50 0.00 Expected volatility 81.3 % — % Risk-free interest rate 0.9 % — % Expected dividends — —

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company recorded no federal provision for income taxes as of December 31, 2021 and 2020 due to reported net losses since inception. The difference between the Company’s provision for income taxes and the amounts computed by applying the statutory federal income tax rate to income before income taxes is as follows for the years ended December 31, 2021 and 2020 (amounts in thousands): Year Ended December 31, 2021 2020 Income tax benefit computed at federal statutory tax rate $ (9,445) $ (7,687) Change in valuation allowance 13,045 8,717 Return to provision adjustments — (745) General business credits (3,108) (1,114) Other permanent differences — 119 Stock compensation (1,923) — Section 162(m) limitation 809 — Change in uncertain tax position 622 223 Other — 487 Income tax benefit $ — $ — Significant components of the Company’s deferred tax assets and liabilities as of December 31, 2021 and 2020 are as follows (amounts in thousands): December 31, 2021 2020 Deferred tax asset: Net operating loss carryforwards $ 20,460 $ 9,891 Accrued expenses and other 3,520 1,345 Stock compensation 779 182 Credit carryforwards 6,194 3,708 Deferred revenue — 2,631 Capital loss carryforwards 484 27 Gross deferred tax asset 31,437 17,784 Less valuation allowance (30,331) (17,285) Net deferred tax asset 1,106 499 Deferred tax liability: Depreciation and amortization (578) (121) Prepaid expenses (528) (378) Total deferred tax liability (1,106) (499) Total net deferred tax asset $ — $ — The Company has established a valuation allowance equal to the net deferred tax asset due to uncertainties regarding the realization of the deferred tax asset based on the Company’s lack of earnings history. The valuation allowance increased by $13.0 million and $8.7 million during the years ended December 31, 2021 and 2020, respectively, primarily due to continuing loss from operations, general business credit carryforwards, and accrued expenses. As of December 31, 2021 and 2020, the Company had gross U.S. net operating loss (“NOL”) carryforwards of $97.4 million and $47.1 million, respectively. Additionally, as of December 31, 2021 and 2020, the Company had capital loss carryforwards of $2.3 million and $0.1 million, respectively. As of December 31, 2021 and 2020, the Company had gross state NOL carryforwards of $0.2 million and $0.2 million, respectively. As of December 31, 2021 and 2020, the Company had gross U.S. tax credit carryforwards of $7.6 million and $4.5 million, respectively. The NOL, capital loss, and tax credit carryforwards will begin to expire in 2036, if not utilized. The NOL, capital loss, and credit carryforwards are subject to Internal Revenue Service adjustments until the statute closes on the year the net operating loss or credit carryforwards are utilized. Section 382 of the Internal Revenue Code limits the utilization of U.S. NOLs following a change of control. After the 2019 financial statements were filed, the Company completed a Section 382 study from formation through October 14, 2020. Although an ownership change occurred during 2020, no deferred tax assets were impacted by the limitation. A reconciliation of our liability for unrecognized tax benefits is as follows: Year Ended December 31, 2021 2020 Balance, beginning of the year $ 783 $ 560 Increase for tax positions related to the current year 449 223 Increase for tax positions related to prior years 172 — Balance, end of year $ 1,404 $ 783 All of the Company’s gross unrecognized tax benefits, if recognized, would affect its effective tax rate. The Company does not expect unrecognized tax benefits to decrease within the next twelve months due to the lapse of statute limitations. The Company recognizes accrued interest and penalties related to unrecognized tax benefits as a component of income tax expense. As of December 31, 2021, the Company has not accrued any interest or penalties related to unrecognized tax benefits. The Company files income tax returns in the U.S. and state jurisdictions. The Company is subject to examination by taxing authorities in its significant jurisdictions for the 2018, 2019, and 2020 tax years. There are currently no federal or state income tax audits in progress.

Related Party

Related Party	12 Months Ended
	Dec. 31, 2021
Related Party Transactions [Abstract]
Related Party	Related PartyAs of December 31, 2020, Takeda held an approximate 5.0% ownership interest in the Company’s outstanding shares. Considering the resignation of the Takeda director and percent ownership of the Company’s common stock as of December 31, 2020, the Company no longer considers Takeda a related party.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2021
Subsequent Events [Abstract]
Subsequent Events	Subsequent EventsNone.

Basis of Presentation and Sum_2

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying audited financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”).
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Significant estimates and assumptions reflected in these financial statements include, but are not limited to, revenue recognition, the accrual of research and development expenses, and the valuation of stock-based awards. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Changes in estimates, if any, are recorded in the period in which they become known and actual results could differ from management’s estimates. A change in the Company’s estimates occurred in the second quarter of 2021, which impacted the Company’s revenue recognition and related balance sheet accounts.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Fair value is defined as the price that would be received upon the sale of an asset or paid upon the transfer of a liability in an orderly transaction between market participants at the measurement date and in the principal or most advantageous market for that asset or liability. Fair value measurements are classified and disclosed in one of the following categories: • Level 1: Observable inputs such as quoted prices in active markets for identical assets the reporting entity has the ability to access as of the measurement date; • Level 2: Inputs, other than quoted prices in active markets, that are observable either directly or indirectly; and • Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. Fair value measurements are classified based on the lowest level of input that is significant to the measurement. The Company’s assessment of the significance of a particular input to the fair value measurement requires judgment, which may affect the valuation of the assets and liabilities and their placement within the fair value hierarchy levels. The determination of the fair values stated below takes into account the market for its financial assets and liabilities, the associated credit risk and other factors as required. The Company considers active markets as those in which transactions for the assets or liabilities occur with sufficient frequency and volume to provide pricing information on an ongoing basis. Management believes that the carrying amounts of the Company’s financial instruments, including short-term investments and accounts payable, approximate fair value due to the short-term nature of those instruments.
Concentration of Risk	Concentration of Risk Financial instruments that potentially subject the Company to concentrations of credit risk primarily consist of cash, cash equivalents and short-term investments. The Company maintains its cash and cash equivalents at two accredited financial institutions in amounts that exceed federally-insured limits. The Company does not believe that it is subject to unusual credit risk beyond the normal credit risk associated with commercial banking relationships. The Company invests in only highly rated debt securities that management believes protects the Company from risk of default and impairment of value. All of the Company’s revenue is derived from its collaboration agreement with Millennium Pharmaceuticals, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited (“Takeda”), which was mutually terminated pursuant to the termination agreement, dated November 8, 2021. The Company is highly dependent on one third-party contract manufacturing organization (“CMO”) to supply drug products for its research and development activities of its programs, including clinical trials and non-clinical studies. These programs could be adversely affected by a significant interruption in the supply of such drug products. The Company is highly dependent on three contract research organizations (“CROs”) and a limited number of third-party service providers to manage and support its clinical trials. These programs could be adversely affected by a significant disruption in services provided by these CROs and third parties.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all demand deposits with financial institutions and all highly liquid investments with original maturities of 90 days or less at the date of purchase to be cash and cash equivalents. Cash and cash equivalents consisted of $14.6 million held in operating accounts and $77.7 million held in money market funds as of December 31, 2021 and $2.7 million held in operating accounts, $80.2 million held in money market funds and $75.0 million held in government obligations as of December 31, 2020.
Short-Term Investments	Short-Term Investments Short-term investments consist of highly-rated U.S. Treasury securities with maturities of more than three months but less than one year at the date of purchase. The Company classifies its short-term investments at the time of purchase as available-for-sale securities. Available-for-sale securities are carried at fair value. Credit impairments for available-for-sale debt securities are recorded through an allowance rather than a direct write-down of the security and are recorded through a charge to the statements of operations. Unrealized gains or losses not related to credit impairments are recorded in accumulated other comprehensive income, a component of stockholders’ equity, until realized. The Company reviews available-for-sale debt securities for impairments related to credit losses and other factors each quarter. As of December 31, 2021, there were no impairments related to credit losses of short-term investments.
Deferred Offering Costs	Deferred Offering Costs The Company capitalizes certain legal, accounting and other third-party fees that are directly associated with in-process equity financings as deferred offering costs until such financings are consummated. After consummation of the equity financing, these costs will be recorded against gross proceeds.
Series A, Series B and Series B-1 Redeemable Convertible Preferred Stock	Series A, Series B and Series B-1 Redeemable Convertible Preferred Stock The Company records shares of redeemable convertible preferred stock at their respective fair values on the date of issuance, net of issuance costs. The redeemable convertible preferred stock is recorded outside of stockholders’ equity on the balance sheet because the shares contain liquidation features that are not solely within the Company’s control. Upon the completion of the Company’s initial public offering (“IPO”) in the fourth quarter of 2020, all outstanding shares of the Company’s redeemable convertible preferred stock were converted into common stock.
Prepaid Expenses and Other Current Assets	Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets include prepaid expenses for general business purposes and services used in research projects, which are stated at cost and amortized on a straight-line basis over the related period of benefit. Supplies and materials that have multiple applications for alternative future use are expensed as they are consumed.
Property and Equipment	Property and Equipment Property and equipment are stated at cost, net of accumulated depreciation. Depreciation expense is recognized using the straight-line method over the estimated useful life of the asset. Expenditures for repairs and maintenance that do not extend the estimated useful life or improve an asset are expensed as incurred. Upon retirement or sale, the cost and related accumulated depreciation and amortization of assets disposed of are removed from the accounts, and any resulting gain or loss is included in the statement of operations and comprehensive loss. Depreciation periods are as follows: Office equipment 3 years Furniture and fixtures 5 to 10 years Lab equipment 5 years Leasehold improvements Shorter of lease term or 15 years
Impairment of Long-Lived Assets	Impairment of Long-Lived AssetsLong-lived assets are reviewed for indications of possible impairment whenever events or changes in circumstance indicate that the carrying amount of an asset may not be recoverable. Recoverability is measured by comparison of the carrying amounts to the future undiscounted cash flows attributable to these assets. An impairment loss is recognized to the extent an asset group is not recoverable and the carrying amount exceeds the projected discounted future cash flows arising from these assets.
Deferred Rent	Deferred Rent The Company records rent expense on a straight-line basis over the term of the leases and, accordingly records the difference between cash payments and the recognition of rent expense as a deferred rent asset or liability. Incentives granted under the Company’s leases, including allowances to fund leasehold improvements, are deferred and recognized as adjustments to rent expense on a straight-line basis over the term of the leases.
Revenue Recognition	Revenue Recognition Collaboration revenue is recognized in accordance with ASC 606, Revenue from Contracts with Customers (“ASC 606”). Arrangements with collaborators may include licenses to intellectual property, research and development services, manufacturing services for clinical and commercial supply and participation on joint steering committees. The Company evaluates the promised goods or services in the contract to determine which promises, or group of promises, represent performance obligations. In contemplation of whether a promised good or service meets the criteria required of a performance obligation, the Company considers the stage of development of the underlying intellectual property, the capabilities and expertise of the customer relative to the underlying intellectual property and whether the promised goods or services are integral to or dependent on other promises in the contract. When accounting for an arrangement that contains multiple performance obligations, the Company must develop judgmental assumptions, which may include market conditions, reimbursement rates for personnel costs, development timelines and probabilities of regulatory success to determine the stand-alone selling price for each performance obligation identified in the contract. Upon the amendment of an existing agreement, the Company evaluates whether the amendment represents a modification to an existing contract which would be recorded through a cumulative catch-up to revenue, or a separate contract. If it is determined that it is a separate contract, the Company will evaluate the necessary revenue recognition through the five-step process described below. When the Company concludes that a contract should be accounted for as a combined performance obligation and recognized over time, the Company must then determine the period over which revenue should be recognized and the method by which to measure revenue. The Company generally recognizes revenue using a cost-based input method. The Company recognizes collaboration revenue in an amount that reflects the consideration that the Company expects to receive in exchange for those goods or services when its customer or collaborator obtains control of promised goods or services. To determine revenue recognition for arrangements that the Company determines are within the scope of ASC 606, the following five steps are performed: i. identify the contract(s) with a customer; ii. identify the performance obligations in the contract; iii. determine the transaction price; iv. allocate the transaction price to the performance obligations within the contract; and v. recognize revenue when (or as) the entity satisfies a performance obligation. The Company only applies the five-step model to contracts when it determines that it is probable it will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, once the contract is determined to be within the scope of ASC 606, the Company assesses the goods or services promised within the contract to determine whether each promised good or service is a performance obligation. The promised goods or services in the Company’s arrangements may consist of a license of, or options to license, the Company’s intellectual property and research, development and manufacturing services. The Company may provide options to additional items in such arrangements, which are accounted for as separate contracts when the customer elects to exercise such options, unless the option provides a material right to the customer. Performance obligations are promises in a contract to transfer a distinct good or service to the customer that (i) the customer can benefit from on its own or together with other readily available resources and (ii) are separately identifiable from other promises in the contract. Goods or services that are not individually distinct performance obligations are combined with other promised goods or services until such combined group of promises meet the requirements of a performance obligation. The Company determines transaction price based on the amount of consideration the Company expects to receive for transferring the promised goods or services in the contract. Consideration may be fixed, variable or a combination of both. At contract inception for arrangements that include variable consideration, the Company estimates the probability and extent of consideration it expects to receive under the contract utilizing either the most-likely amount method or expected amount method, whichever best estimates the amount expected to be received. The Company then considers any constraints on the variable consideration and includes variable consideration in the transaction price to the extent it is deemed probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. The Company then allocates the transaction price to each performance obligation based on the relative standalone selling price and recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) control is transferred to the customer and the performance obligation is satisfied. For performance obligations which consist of licenses and other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. The Company records amounts as accounts receivable when the right to consideration is deemed unconditional. When consideration is received, or such consideration is unconditionally due, from a customer prior to transferring goods or services to the customer under the terms of a contract, a contract liability is recorded as deferred revenue. Amounts received prior to satisfying the revenue recognition criteria are recognized as deferred revenue in the Company’s accompanying balance sheet. Deferred revenues expected to be recognized as revenue within the 12 months following the balance sheet date are classified as a current liability. Deferred revenues not expected to be recognized as revenue within the 12 months following the balance sheet date are classified as non-current liabilities. The Company’s collaboration revenue arrangements may include the following: Up-front License Fees: If a license is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenues from nonrefundable, up-front fees allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, up-front fees. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. Milestone Payments: At the inception of an agreement that includes research and development milestone payments, the Company evaluates each milestone to determine when and how much of the milestone to include in the transaction price. The Company first estimates the amount of the milestone payment that the Company could receive using either the expected value or the most-likely amount approach. The Company primarily uses the most-likely amount approach as that approach is generally most predictive for milestone payments with a binary outcome. The Company then considers whether any portion of that estimated amount is subject to the variable consideration constraint (that is, whether it is probable that a significant reversal of cumulative revenue would not occur upon resolution of the uncertainty). The Company updates the estimate of variable consideration included in the transaction price at each reporting date which includes updating the assessment of the likely amount of consideration and the application of the constraint to reflect current facts and circumstances. Royalties: For arrangements that include sales-based royalties, including milestone payments based on a level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company will recognize revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). To date, the Company has not granted a development and commercialization license nor recognized any revenue related to sales-based royalties or milestone payments based on the level of sales. Research and Development Services: The Company will record costs associated with development and process optimization activities as research and development expenses in the statements of operations and comprehensive loss consistent with ASC 730, Research and Development. The Company considered the guidance in ASC 808, Collaborative Agreements
Research and Development Costs	Research and Development Costs Research and development costs are expensed as incurred, and include salaries, stock-based compensation and other personnel-related costs, equipment and supplies, depreciation, nonclinical studies, clinical trials and manufacturing development activities.
Stock-Based Compensation	Stock-Based Compensation The Company recognizes the grant-date fair value of stock-based awards issued to employees and nonemployee Board members as compensation expense on a straight-line basis over the vesting period of the award. The Company uses the Black-Scholes option pricing model to determine the grant-date fair value of stock options. The Company adjusts expense for forfeitures in the periods they occur.
Income Taxes	Income Taxes The Company uses the asset and liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the financial statements and the tax bases of assets and liabilities. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect of a change in tax rates on deferred tax assets and liabilities will be recognized in the period that includes the enactment date. Additionally, any changes in income tax laws are immediately recognized in the year of enactment. A valuation allowance is established against the deferred tax assets to reduce their carrying value to an amount that is more likely than not to be realized. The deferred tax assets and liabilities are classified as noncurrent along with the related valuation allowance. Due to a lack of earnings history, the net deferred tax assets have been fully offset by a valuation allowance. The Company recognizes benefits of uncertain tax positions if it is more likely than not that such positions will be sustained upon examination based solely on the technical merits, as the largest amount of benefits that is more likely than not to be realized upon the ultimate settlement. The Company’s policy is to recognize interest and penalties related to the unrecognized tax benefits as a component of income tax expense.
Net Loss Per Share	Net Loss Per Share Basic loss per share of common stock is computed by dividing net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding during each period. Diluted loss per share of common stock includes the effect, if any, from the potential exercise or conversion of securities, such as redeemable convertible preferred stock, convertible notes, stock options and unvested shares of restricted stock, which would result in the issuance of incremental shares of common stock. For diluted net loss per share, the weighted-average number of shares of common stock is the same for basic net loss per share due to the fact that when a net loss exists, dilutive securities are not included in the calculation as the impact is anti-dilutive.
Other Comprehensive Income (Loss)	Other Comprehensive Income (Loss)Other comprehensive income (loss) is defined as the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. Other comprehensive income (loss) is comprised of the net loss and unrealized gains and losses on short-term investments.
Recently Adopted Accounting Pronouncements and Recently Issued Accounting Pronouncements (not yet adopted)	Recently Adopted Accounting Pronouncements In December 2019, the Financial Accounting Standards Board (the “FASB”) issued ASU No. 2019-12, Income Taxes: Simplifying the Accounting for Income Taxes . The ASU removes certain exceptions to the general principles in ASC 740, Income Taxes and also clarifies and amends existing guidance to improve consistent application. This ASU is effective for fiscal years beginning after December 15, 2020, including interim periods within that fiscal year, with early adoption permitted. The Company adopted this pronouncement effective January 1, 2021 and it did not have a material impact on the financial statements or related disclosures. Recently Issued Accounting Pronouncements (not yet adopted) In February 2016, the FASB issued ASU No. 2016-02, Leases which requires a lessee to record a right-of-use asset and a corresponding lease liability on the balance sheet for all leases with terms longer than 12 months. A modified retrospective

Basis of Presentation and Sum_3

Basis of Presentation and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of property and equipment depreciation periods	Depreciation periods are as follows: Office equipment 3 years Furniture and fixtures 5 to 10 years Lab equipment 5 years Leasehold improvements Shorter of lease term or 15 years
Schedule of antidilutive securities excluded from computation of net loss per share	The following potentially dilutive securities have been excluded from the computation of diluted weighted-average shares of common stock outstanding, as they would be anti-dilutive: December 31, 2021 2020 Stock options 2,448,676 2,742,022 Unvested restricted stock — 11,752 2,448,676 2,753,774

Short-Term Investments (Tables)

Short-Term Investments (Tables)	12 Months Ended
	Dec. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Schedule of available for sale short-term investments	The following table represents the Company’s available for sale short-term investments by major security type (amounts in thousands): December 31, 2021 Amortized Cost Gross Unrealized Loss Total Fair Value Short-term investments: U.S. government securities $ 177,096 $ (560) $ 176,536 Total short-term investments $ 177,096 $ (560) $ 176,536 December 31, 2020 Amortized Cost Gross Unrealized Loss Total Fair Value Short-term investments: U.S. government securities $ 177,614 $ (63) $ 177,551 Total short-term investments $ 177,614 $ (63) $ 177,551

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2021
Property, Plant and Equipment [Abstract]
Schedule of property and equipment	Property and equipment consisted of the following (amounts in thousands): December 31, 2021 2020 Lab equipment $ 5,823 $ 2,790 Leasehold improvements 3,709 1,073 Construction in progress 2,521 355 Furniture and fixtures 459 157 Office equipment 206 105 12,718 4,480 Accumulated depreciation and amortization (2,780) (1,480) Property and equipment, net $ 9,938 $ 3,000

Accrued Expenses (Tables)

Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2021
Payables and Accruals [Abstract]
Schedule of accrued expenses	Accrued expenses consisted of the following (amounts in thousands): December 31, 2021 2020 Research and development contract costs $ 10,253 $ 5,382 Compensation and related benefits 3,320 1,551 Other 1,001 419 Total accrued expenses $ 14,574 $ 7,352

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Schedule of future minimum rental payments for operating leases	As of December 31, 2021, future minimum payments, by year and in aggregate, under non-cancelable operating leases consist of the following (amounts in thousands): 2022 $ 1,058 2023 1,089 2024 1,120 2025 1,152 2026 1,093 Thereafter 1,721 Total minimum lease payments $ 7,233

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2021
Share-based Payment Arrangement [Abstract]
Schedule of stock-based compensation expense	The Company recorded stock-based compensation expense in the following expense categories of its accompanying audited statements of operations and comprehensive loss (amounts in thousands): Year Ended December 31, 2021 2020 Research and development $ 2,200 $ 531 General and administrative 3,267 735 Total stock-based compensation $ 5,467 $ 1,266
Schedule of option activity	The following table summarizes option activity under the 2020 Plan and the 2016 Stock Incentive Plan: Options Weighted Average Exercise Price Weighted Average Remaining Life (Years) Balance at January 1, 2021 2,742,022 $ 7.95 8.82 Granted 325,671 23.60 Exercised (557,609) 3.40 Forfeited (61,408) 12.13 Balance at December 31, 2021 2,448,676 $ 10.96 8.08 Vested and expected to vest 2,418,923 $ 10.88 8.07 Exercisable at the end of the period 1,259,440 $ 6.44 7.55
Schedule of valuation assumptions	The grant-date fair value of options granted under the Company’s 2020 Plan were estimated throughout the year using the Black-Scholes option-pricing model using the following weighted-average assumptions: Year Ended December 31, 2021 2020 Expected term - years 6.08 5.94 Expected volatility 81.4 % 75.3 % Risk-free interest rate 1.1 % 0.5 % Expected dividends — — The grant-date fair value of shares issued under the Company’s 2020 ESPP were estimated throughout the year using the Black-Scholes option-pricing model using the following weighted-average assumptions: Year Ended December 31, 2021 2020 Expected term - years 0.50 0.00 Expected volatility 81.3 % — % Risk-free interest rate 0.9 % — % Expected dividends — —
Schedule of restricted stock activity	The following table summarizes the activity relating to these shares: Awards Outstanding at December 31, 2020 11,752 Vested (11,752) Outstanding at December 31, 2021 —

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Schedule of income tax reconciliation	The difference between the Company’s provision for income taxes and the amounts computed by applying the statutory federal income tax rate to income before income taxes is as follows for the years ended December 31, 2021 and 2020 (amounts in thousands): Year Ended December 31, 2021 2020 Income tax benefit computed at federal statutory tax rate $ (9,445) $ (7,687) Change in valuation allowance 13,045 8,717 Return to provision adjustments — (745) General business credits (3,108) (1,114) Other permanent differences — 119 Stock compensation (1,923) — Section 162(m) limitation 809 — Change in uncertain tax position 622 223 Other — 487 Income tax benefit $ — $ —
Schedule of deferred tax assets and liabilities	Significant components of the Company’s deferred tax assets and liabilities as of December 31, 2021 and 2020 are as follows (amounts in thousands): December 31, 2021 2020 Deferred tax asset: Net operating loss carryforwards $ 20,460 $ 9,891 Accrued expenses and other 3,520 1,345 Stock compensation 779 182 Credit carryforwards 6,194 3,708 Deferred revenue — 2,631 Capital loss carryforwards 484 27 Gross deferred tax asset 31,437 17,784 Less valuation allowance (30,331) (17,285) Net deferred tax asset 1,106 499 Deferred tax liability: Depreciation and amortization (578) (121) Prepaid expenses (528) (378) Total deferred tax liability (1,106) (499) Total net deferred tax asset $ — $ —
Schedule of unrecognized tax benefits	A reconciliation of our liability for unrecognized tax benefits is as follows: Year Ended December 31, 2021 2020 Balance, beginning of the year $ 783 $ 560 Increase for tax positions related to the current year 449 223 Increase for tax positions related to prior years 172 — Balance, end of year $ 1,404 $ 783

Organization and Description _2

Organization and Description of Business (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accumulated deficit	$ 117,067	$ 72,093
Cash, cash equivalents, and short-term investments	$ 268,800

Basis of Presentation and Sum_4

Basis of Presentation and Summary of Significant Accounting Policies - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Impairments of long-lived assets	$ 0	$ 0
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	92,268,000	157,898,000
Operating Account
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	14,600,000	2,700,000
Money Market Funds
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 77,700,000	80,200,000
Government Obligations
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents		$ 75,000,000

Basis of Presentation and Sum_5

Basis of Presentation and Summary of Significant Accounting Policies - Schedule of property and equipment depreciation and amortization periods (Details)	12 Months Ended
	Dec. 31, 2021
Office equipment
Property, Plant and Equipment [Line Items]
Property and equipment depreciation and amortization periods	3 years
Furniture and fixtures | Minimum
Property, Plant and Equipment [Line Items]
Property and equipment depreciation and amortization periods	5 years
Furniture and fixtures | Maximum
Property, Plant and Equipment [Line Items]
Property and equipment depreciation and amortization periods	10 years
Lab equipment
Property, Plant and Equipment [Line Items]
Property and equipment depreciation and amortization periods	5 years
Leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Property and equipment depreciation and amortization periods	15 years

Basis of Presentation and Sum_6

Basis of Presentation and Summary of Significant Accounting Policies - Schedule of anti-dilutive securities (Details) - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from the computation of diluted weighted-average shares of common stock outstanding (in shares)	2,448,676	2,753,774
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from the computation of diluted weighted-average shares of common stock outstanding (in shares)	2,448,676	2,742,022
Unvested restricted stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from the computation of diluted weighted-average shares of common stock outstanding (in shares)	0	11,752

Short-Term Investments - Schedu

Short-Term Investments - Schedule of available for sale short-term investments (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Short-term investments
Amortized Cost	$ 177,096	$ 177,614
Gross Unrealized Loss	(560)	(63)
Total Fair Value	176,536	177,551
U.S. government securities
Short-term investments
Amortized Cost	177,096	177,614
Gross Unrealized Loss	(560)	(63)
Total Fair Value	$ 176,536	$ 177,551

Short-Term Investments - Narrat

Short-Term Investments - Narrative (Details)	Dec. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Debt securities, average maturity term	5 months 4 days

Property and Equipment - Schedu

Property and Equipment - Schedule of property and equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 12,718	$ 4,480
Accumulated depreciation and amortization	(2,780)	(1,480)
Property and equipment, net	9,938	3,000
Lab equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	5,823	2,790
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	3,709	1,073
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	2,521	355
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	459	157
Office equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 206	$ 105

Property and Equipment - Narrat

Property and Equipment - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Depreciation and amortization expense	$ 1.4	$ 0.6

Accrued Expenses - Schedule of

Accrued Expenses - Schedule of accrued expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Payables and Accruals [Abstract]
Research and development contract costs	$ 10,253	$ 5,382
Compensation and related benefits	3,320	1,551
Other	1,001	419
Total accrued expenses	$ 14,574	$ 7,352

Commitments and Contingencies -

Commitments and Contingencies - Schedule of minimum lease payments (Details) $ in Thousands	Dec. 31, 2021USD ($)
Commitments and Contingencies Disclosure [Abstract]
2022	$ 1,058
2023	1,089
2024	1,120
2025	1,152
2026	1,093
Thereafter	1,721
Total minimum lease payments	$ 7,233

Commitments and Contingencies_2

Commitments and Contingencies - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Rent expense	$ 0.7	$ 0.4
License agreement, maximum payment	$ 20.6

Preferred Stock (Details)

Preferred Stock (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)$ / sharesshares
Redeemable Convertible Preferred Stock
Temporary Equity [Line Items]
Sale of stock, proceeds received | $	$ 117
Series B Redeemable Convertible Preferred Stock
Temporary Equity [Line Items]
Preferred stock sold (in shares) | shares	550,571
Sale of preferred stock (in dollars per share) | $ / shares	$ 62.88051
Series B-1 Redeemable Convertible Preferred Stock
Temporary Equity [Line Items]
Preferred stock sold (in shares) | shares	1,319,964
Sale of preferred stock (in dollars per share) | $ / shares	$ 62.88051

Collaboration Agreement - Rel_2

Collaboration Agreement - Related Party (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Related Party Transaction [Line Items]
Collaboration revenue - related party	$ 30,017	$ 9,934
Takeda | Investor | Collaborative Arrangement
Related Party Transaction [Line Items]
Proceeds from collaborators	3,600	$ 14,000
Collaboration revenue - related party	$ 82,000

Stock-Based Compensation - Narr

Stock-Based Compensation - Narrative (Details) $ / shares in Units, $ in Thousands	Jan. 01, 2022shares	Jan. 01, 2021	Oct. 14, 2020USD ($)shares	Dec. 31, 2021USD ($)$ / sharesshares	Dec. 31, 2020USD ($)$ / sharesshares	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock issued under ESPP (in shares)				2,106
Proceeds from stock plans | $				$ 100
Grant date fair value (in dollars per share) | $ / shares				$ 16.38	$ 8.93
Unrecognized compensation cost | $				$ 11,400
Aggregate intrinsic value of options exercised | $				10,800	$ 49,700
Aggregate intrinsic value of options outstanding | $				5,900
Aggregate intrinsic value of options exercisable | $				$ 5,900
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average amortization period				2 years 5 months 23 days
Expected dividends (in percentage)				0.00%
2020 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in number of shares authorized, percentage of capital stock outstanding						0.04
Number of shares available for future grant (in shares)				3,912,408
Stock-based compensation, vesting period				4 years
Share-based compensation, expiration period				10 years
2020 Stock Incentive Plan | Subsequent Event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional number of shares reserved for future issuance (in shares)	1,693,555
2020 Stock Incentive Plan | Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividends (in percentage)				0.00%	0.00%
2020 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in number of shares authorized, percentage of capital stock outstanding			0.01
Number of shares available for future grant (in shares)			395,795	393,689
Purchase price of common stock in percent			85.00%
Contribution limit in percentage of employee's eligible compensation			15.00%
Maximum value of shares per employee during any calendar year | $			$ 25,000
Maximum number of shares per employee during any one purchase period (in shares)			600
Share-based compensation arrangement by share-based payment award, annual increase in number of shares authorized, term		10 years
Stock issued under ESPP (in shares)					0
2020 Employee Stock Purchase Plan | Subsequent Event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional number of shares reserved for future issuance (in shares)	423,388

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of stock-based compensation expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 5,467	$ 1,266
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	2,200	531
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 3,267	$ 735

Stock-Based Compensation - Sc_2

Stock-Based Compensation - Schedule of option activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Options
Options, beginning balance (in shares)	2,742,022
Options, granted (in shares)	325,671
Options, exercised (in shares)	(557,609)
Options, forfeited (in shares)	(61,408)
Options, ending balance (in shares)	2,448,676	2,742,022
Options, vested and expected to vest (in shares)	2,418,923
Options, exercisable (in shares)	1,259,440
Weighted average exercise price
Weighted average exercise price, beginning balance (in dollars per share)	$ 7.95
Weighted average exercise price, granted (in dollars per share)	23.60
Weighted average exercise price, exercised (in dollars per share)	3.40
Weighted average exercise price, forfeited (in dollars per share)	12.13
Weighted average exercise price, ending balance (in dollars per share)	10.96	$ 7.95
Weighted average exercise price, vested and expected to vest (in dollars per share)	10.88
Weighted average exercise price, exercisable (in dollars per share)	$ 6.44
Weighted average remaining contract life
Weighted average remaining contract life, outstanding	8 years 29 days	8 years 9 months 25 days
Weighted average remaining contract life, vested and expected to vest	8 years 25 days
Weighted average remaining contract life, exercisable	7 years 6 months 18 days

Stock-Based Compensation - Sc_3

Stock-Based Compensation - Schedule of 2020 Plan valuation assumptions (Details) - Stock options	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividends (in percentage)	0.00%
2020 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term - years	6 years 29 days	5 years 11 months 8 days
Expected volatility	81.40%	75.30%
Risk-free interest rate	1.10%	0.50%
Expected dividends (in percentage)	0.00%	0.00%

Stock-Based Compensation - Sc_4

Stock-Based Compensation - Schedule of 2020 ESPP valuation assumptions (Details) - Employee Stock - 2020 Employee Stock Purchase Plan	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term - years	6 months	0 years
Expected volatility	81.30%	0.00%
Risk-free interest rate	0.90%	0.00%
Expected dividends (in percentage)	0.00%	0.00%

Stock-Based Compensation - Sc_5

Stock-Based Compensation - Schedule of restricted stock activity (Details) - Restricted Stock	12 Months Ended
	Dec. 31, 2021shares
Awards
Awards, beginning balance (in shares)	11,752
Awards, vested (in shares)	(11,752)
Awards, ending balance (in shares)	0

Income Taxes - Schedule of effe

Income Taxes - Schedule of effective income tax rate reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income tax benefit computed at federal statutory tax rate	$ (9,445)	$ (7,687)
Change in valuation allowance	13,045	8,717
Return to provision adjustments	0	(745)
General business credits	(3,108)	(1,114)
Other permanent differences	0	119
Stock compensation	(1,923)	0
Section 162(m) limitation	809	0
Change in uncertain tax position	622	223
Other	0	487
Income tax benefit	$ 0	$ 0

Income Taxes - Schedule of defe

Income Taxes - Schedule of deferred tax assets and liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax asset:
Net operating loss carryforwards	$ 20,460	$ 9,891
Accrued expenses and other	3,520	1,345
Stock compensation	779	182
Credit carryforwards	6,194	3,708
Deferred revenue	0	2,631
Capital loss carryforwards	484	27
Gross deferred tax asset	31,437	17,784
Less valuation allowance	(30,331)	(17,285)
Net deferred tax asset	1,106	499
Deferred tax liability:
Depreciation and amortization	(578)	(121)
Prepaid expenses	(528)	(378)
Total deferred tax liability	(1,106)	(499)
Total net deferred tax asset	$ 0	$ 0

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating Loss Carryforwards [Line Items]
Valuation allowance increase (decrease)	$ 13	$ 8.7
Capital Loss Carryforward
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	2.3	0.1
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	97.4	47.1
Tax credit carryforward	7.6	4.5
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 0.2	$ 0.2

Income Taxes - Schedule of unre

Income Taxes - Schedule of unrecognized tax benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance, beginning of the year	$ 783	$ 560
Increase for tax positions related to the current year	449	223
Increase for tax positions related to prior years	172	0
Balance, end of year	$ 1,404	$ 783

Related Party (Details)

Related Party (Details)	Dec. 31, 2020
Takeda
Related Party Transaction [Line Items]
Shareholder ownership percentage	0.050