0001564590-22-028596 | 10-Q | XBRL Viewer

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Document and Entity Information - shares	6 Months Ended
Document and Entity Information - shares	Jun. 30, 2022	Aug. 02, 2022
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q2
Trading Symbol	PRLD
Entity Registrant Name	PRELUDE THERAPEUTICS INC
Entity Central Index Key	0001678660
Entity Current Reporting Status	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Common Stock, Shares Outstanding		47,833,307
Entity Shell Company	false
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Security Exchange Name	NASDAQ
Entity Interactive Data Current	Yes
Entity File Number	001-39527
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	81-1384762
Entity Address, Address Line One	200 Powder Mill Road
Entity Address, City or Town	Wilmington
Entity Address, State or Province	DE
Entity Address, Postal Zip Code	19803
City Area Code	302
Local Phone Number	467-1280
Document Quarterly Report	true
Document Transition Report	false

STATEMENT OF BALANCE SHEETS (UNAUDITED) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 50,706	$ 31,828
Marketable securities	195,599	259,405
Prepaid expenses and other current assets	2,319	3,882
Total current assets	248,624	295,115
Restricted cash	4,044	4,044
Property and equipment, net	4,285	3,929
Right-of-use asset	1,793	1,707
Other assets	309	303
Total assets	259,055	305,098
Current liabilities:
Accounts payable	6,273	7,840
Accrued expenses and other current liabilities	7,716	9,621
Operating lease liability	1,822	1,740
Total current liabilities	15,811	19,201
Other liabilities	2,400
Total liabilities	18,211	19,201
Commitments (Note 8)
Stockholders’ equity:
Additional paid-in capital	519,092	505,723
Accumulated other comprehensive income (loss)	(2,294)	(711)
Accumulated deficit	(275,959)	(219,120)
Total stockholders’ equity	240,844	285,897
Total liabilities and stockholders’ equity	259,055	305,098
Voting Common Stock
Stockholders’ equity:
Common stock	4	4
Non-voting Common Stock
Stockholders’ equity:
Common stock	$ 1	$ 1

STATEMENT OF BALANCE SHEETS (PARENTHETICAL) (UNAUDITED) - $ / shares	Jun. 30, 2022	Dec. 31, 2021
Voting Common Stock
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	487,149,741	487,149,741
Common stock, shares, issued	36,369,248	36,200,299
Common stock, shares, outstanding	36,369,248	36,200,299
Non-voting Common Stock
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	12,850,259	12,850,259
Common stock, shares, issued	11,402,037	11,402,037
Common stock, shares, outstanding	11,402,037	11,402,037

STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Operating expenses:
Research and development	$ 21,310	$ 22,409	$ 44,131	$ 38,879
General and administrative	8,151	5,513	15,618	11,010
Total operating expenses	29,461	27,922	59,749	49,889
Loss from operations	(29,461)	(27,922)	(59,749)	(49,889)
Other income, net	2,087	1,057	2,910	1,724
Net loss	$ (27,374)	$ (26,865)	$ (56,839)	$ (48,165)
Per share information:
Net loss per share of common stock, basic	$ (0.58)	$ (0.58)	$ (1.20)	$ (1.06)
Weighted average common shares outstanding, basic	47,276,684	46,057,112	47,172,136	45,592,117
Net loss per share of common stock, diluted	$ (0.58)	$ (0.58)	$ (1.20)	$ (1.06)
Weighted average common shares outstanding, diluted	47,276,684	46,057,112	47,172,136	45,592,117
Comprehensive loss
Net loss	$ (27,374)	$ (26,865)	$ (56,839)	$ (48,165)
Unrealized gain (loss) on marketable securities, net of tax	19		(1,583)
Comprehensive loss	$ (27,355)	$ (26,865)	$ (58,422)	$ (48,165)

STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (DEFICIT) (UNAUDITED) - USD ($) $ in Thousands	Total	Common Stock Voting Common Stock	Common Stock Non-voting Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning balance at Dec. 31, 2020	$ 212,183	$ 3	$ 1	$ 319,605		$ (107,426)
Beginning balance (shares) at Dec. 31, 2020		32,595,301	11,110,371
Issuance of common stock upon exercise of stock options	386			386
Issuance of common stock upon exercise of stock options, (shares)		210,274
Sale of common stock, net of offering costs	161,412	$ 1		161,411
Sale of common stock, net of offering costs, (shares)		2,583,334	291,666
Stock-based compensation expense, net of forfeitures of restricted stock awards	3,886			3,886
Net loss	(21,300)					(21,300)
Ending balance at Mar. 31, 2021	356,567	$ 4	$ 1	485,288		(128,726)
Ending balance (shares) at Mar. 31, 2021		35,388,909	11,402,037
Beginning balance at Dec. 31, 2020	212,183	$ 3	$ 1	319,605		(107,426)
Beginning balance (shares) at Dec. 31, 2020		32,595,301	11,110,371
Net loss	(48,165)
Ending balance at Jun. 30, 2021	334,361	$ 4	$ 1	489,947		(155,591)
Ending balance (shares) at Jun. 30, 2021		35,636,695	11,402,037
Beginning balance at Mar. 31, 2021	356,567	$ 4	$ 1	485,288		(128,726)
Beginning balance (shares) at Mar. 31, 2021		35,388,909	11,402,037
Issuance of common stock upon exercise of stock options	422			422
Issuance of common stock upon exercise of stock options, (shares)		247,786
Stock-based compensation expense, net of forfeitures of restricted stock awards	4,237			4,237
Net loss	(26,865)					(26,865)
Ending balance at Jun. 30, 2021	334,361	$ 4	$ 1	489,947		(155,591)
Ending balance (shares) at Jun. 30, 2021		35,636,695	11,402,037
Beginning balance at Dec. 31, 2021	285,897	$ 4	$ 1	505,723	$ (711)	(219,120)
Beginning balance (shares) at Dec. 31, 2021		36,200,299	11,402,037
Issuance of common stock upon exercise of stock options	153			153
Issuance of common stock upon exercise of stock options, (shares)		93,032
Unrealized gain (loss) on marketable securities	(1,602)				(1,602)
Stock-based compensation expense, net of forfeitures of restricted stock awards	6,829			6,829
Net loss	(29,465)					(29,465)
Ending balance at Mar. 31, 2022	261,812	$ 4	$ 1	512,705	(2,313)	(248,585)
Ending balance (shares) at Mar. 31, 2022		36,293,331	11,402,037
Beginning balance at Dec. 31, 2021	$ 285,897	$ 4	$ 1	505,723	(711)	(219,120)
Beginning balance (shares) at Dec. 31, 2021		36,200,299	11,402,037
Issuance of common stock upon exercise of stock options, (shares)	124,285
Unrealized gain (loss) on marketable securities	$ (1,583)
Net loss	(56,839)
Ending balance at Jun. 30, 2022	240,844	$ 4	$ 1	519,092	(2,294)	(275,959)
Ending balance (shares) at Jun. 30, 2022		36,369,248	11,402,037
Beginning balance at Mar. 31, 2022	261,812	$ 4	$ 1	512,705	(2,313)	(248,585)
Beginning balance (shares) at Mar. 31, 2022		36,293,331	11,402,037
Issuance of common stock upon exercise of stock options	59			59
Issuance of common stock upon exercise of stock options, (shares)		31,253
Issuance of common stock under ESPP	300			300
Issuance of common stock under ESPP, (shares)		68,080
Unrealized gain (loss) on marketable securities	19				19
Stock-based compensation expense, net of forfeitures of restricted stock awards	6,028			6,028
Stock-based compensation expense, net of forfeitures of restricted stock awards (shares)		(23,416)
Net loss	(27,374)					(27,374)
Ending balance at Jun. 30, 2022	$ 240,844	$ 4	$ 1	$ 519,092	$ (2,294)	$ (275,959)
Ending balance (shares) at Jun. 30, 2022		36,369,248	11,402,037

STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (DEFICIT) (PARENTHETICAL) (UNAUDITED) $ in Thousands	3 Months Ended
	Mar. 31, 2021 USD ($)
Statement Of Stockholders Equity [Abstract]
Sale of common stock, offering costs	$ 739

STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows used in operating activities:
Net loss	$ (56,839)	$ (48,165)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	625	359
Noncash lease expense	842	572
Stock-based compensation	12,857	8,123
Amortization of premium and discount on marketable securities, net	1,784
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	1,557	1,044
Accounts payable	(838)	3,327
Accrued expenses and other liabilities	495	(856)
Operating lease liabilities	(846)	(459)
Net cash used in operating activities	(40,363)	(36,055)
Cash flows provided by (used in) investing activities:
Purchases of marketable securities	(27,140)
Proceeds from maturities of marketable securities	87,579
Purchases of property and equipment	(1,710)	(1,367)
Net cash provided by (used in) investing activities	58,729	(1,367)
Cash flows provided by financing activities:
Proceeds from the sale of common stock, net of offering costs		161,424
Proceeds from the issuance of common stock under ESPP	300
Proceeds from the issuance of common stock in connection with the exercise of stock options	212	808
Net cash provided by financing activities	512	162,232
Net increase in cash and cash equivalents	18,878	124,810
Cash, cash equivalents, and restricted cash at beginning of period	35,872	218,309
Cash, cash equivalents, and restricted cash at end of period	54,750	343,119
Supplemental disclosures:
Operating lease right-of-use assets obtained in exchange for operating lease liabilities	928
Property and equipment in accounts payable	77	$ 386
Unrealized loss on marketable securities	$ (1,583)

Background

6 Months Ended

Jun. 30, 2022

Background [Abstract]

Background

1. Background

Prelude Therapeutics Incorporated (the “Company”) was incorporated in Delaware on February 5, 2016 and is a clinical-stage fully integrated oncology company built on a foundation of drug discovery excellence to deliver novel precision cancer medicines to underserved patients. Since beginning operations, the Company has devoted substantially all its efforts to research and development, conducting preclinical and clinical studies, recruiting management and technical staff, administration, and raising capital.

Risks and Liquidity

6 Months Ended

Jun. 30, 2022

Risks And Liquidity [Abstract]

Risks and Liquidity

2. Risks and liquidity

The Company is subject to a number of risks common to early-stage companies in the biotechnology industry. Principal among these risks are the uncertainties in the development process, development of the same or similar technological innovations by competitors, protection of proprietary technology, dependence on key personnel, compliance with government regulations and approval requirements, and the need to obtain additional financing to fund operations. Product candidates currently under development will require significant additional research and development efforts, including extensive pre-clinical and clinical testing and regulatory approval, prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel infrastructure, and extensive compliance-reporting capabilities. There can be no assurance that the Company’s research and development will be successfully completed, that adequate protection for the Company’s technology will be obtained, that any products developed will obtain necessary government regulatory approval, or that any approved products will be commercially viable. The Company operates in an environment of rapid change in technology and substantial competition from pharmaceutical and biotechnology companies. In addition, the Company is dependent upon the services of its employees, consultants and contractors.

Since its inception, the Company has incurred operating losses and has an accumulated deficit of $276.0 million at June 30, 2022. The Company has no revenue to date and devotes its efforts to research and development. The Company anticipates incurring additional losses until such time, if ever, that it can generate significant sales of its product candidates currently in development.

The Company believes that its cash, cash equivalents, and marketable securities as of June 30, 2022 will be sufficient to fund its operating expenses and capital expenditure requirements into the second half of 2024.

To fund its operating expenses and capital expenditure requirements after that date, the Company plans to seek additional funding through public or private equity offerings, debt financings, collaborations, strategic alliances and licensing arrangements. The Company may not be able to obtain financing on acceptable terms, or at all, and the Company may not be able to enter into strategic alliances or other arrangements on favorable terms, or at all. The terms of any financing may adversely affect the holdings or the rights of the Company’s stockholders. If the Company is unable to obtain funding, the Company could be required to delay, reduce or eliminate research and development programs, product portfolio expansion or future commercialization efforts, which could adversely affect its business prospects.

On March 10, 2020, the World Health Organization characterized the novel COVID-19 virus as a global pandemic. There continues to be significant uncertainty as to the effects of this disease and emerging variants which may, among other things, materially impact the Company’s planned clinical trials. This pandemic or outbreak could result in difficulty securing clinical trial site locations, CROs, and/or trial monitors and other critical vendors and consultants supporting the trial. In addition, outbreaks or the perception of an outbreak near a clinical trial site location could impact the Company’s ability to enroll patients. These situations, or others associated with the ongoing COVID-19 pandemic, could cause delays in the Company’s clinical trial plans and could increase expected costs, all of which could have a material adverse effect on the Company’s business and its financial condition. At the current time, the Company is unable to quantify the potential effects of this pandemic on its future financial statements.

Summary of Significant Accounting Policies

6 Months Ended

Jun. 30, 2022

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

3. Summary of significant accounting policies

The summary of significant accounting policies included in the Company’s financial statements for the year ended December 31, 2021 can be found in “Note 3. Summary of significant accounting policies” of the Company’s Form 10-K filed with the Securities and Exchange Commission (the “SEC”) on March 17, 2022. Those policies have not materially changed, except as set forth below.

Basis of presentation

The accompanying unaudited interim financial statements have been prepared in accordance with generally accepted accounting principles (“GAAP”) for interim financial information, the instructions to Form 10-Q and Article 10 of Regulation S-X. They do not include all of the information and notes required by GAAP for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included. Operating results for the three and six months ended June 30, 2022 are not necessarily indicative of the results that may be expected for the year ending December 31, 2022. The accompanying unaudited interim financial statements should be read in conjunction with the annual audited financial statements and related notes as of and for the year ended December 31, 2021 found in the Form 10-K filed with the SEC on March 17, 2022. Any reference in these notes to applicable guidance is meant to refer to GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”).

Use of estimates

The preparation of the unaudited interim financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and contingent liabilities at the date of the unaudited interim financial statements and the reported amounts of expenses during the reporting period. Actual results could differ from those estimates.

Estimates and assumptions are periodically reviewed and the effects of the revisions are reflected in the accompanying unaudited interim financial statements in the period they are determined to be necessary. The most significant estimate relates to accrued clinical trial expenses.

Income taxes

Based upon the historical and anticipated future losses, management has determined that the deferred tax assets generated by net operating losses and research and development credits do not meet the more likely than not threshold for realizability. Accordingly, a full valuation allowance has been recorded against the Company’s net deferred tax assets as of June 30, 2022 and December 31, 2021.

Cash, Cash Equivalents and Restricted cash

The Company’s cash equivalents include short-term highly liquid investments with an original maturity of 90 days or less when purchased and are carried at fair value in the accompanying balance sheets.

Restricted cash comprises a letter of credit for the benefit of the landlord in connection with the Company’s Chestnut Run Lease. See Note 8 for further details.

The following table provides a reconciliation of cash and cash equivalents and restricted cash reported within the balance sheet that total to the amounts shown in the statement of cash flows:

(in thousands)	June 30, 2022		December 31, 2021
Cash and cash equivalents	$	50,706	$	31,828
Restricted cash		4,044		4,044
Total cash, cash equivalents, and restricted cash shown in statement of cash flows	$	54,750	$	35,872

Marketable Securities

The Company’s marketable securities consist of investments in corporate debt securities and commercial paper that are classified as available-for-sale. The securities are carried at fair value with the unrealized gains and losses, net of tax, included in accumulated other comprehensive income (loss), a component of stockholders’ equity (deficit). Realized gains and losses as well as credit losses, if

any, on marketable securities are included in the Company’s statements of operations. The Company classifies marketable securities that are available for use in current operations as current assets on the balance sheets.

Net Loss Per Share

Basic net loss per share of common stock is computed by dividing net loss by the weighted-average number of shares of common stock outstanding during each period. The weighted-average number of shares of common stock outstanding used in the basic net loss per share calculation does not include unvested restricted stock awards as these instruments are considered contingently issuable shares until they vest. Diluted net loss per share of common stock includes the effect, if any, from the potential exercise of securities, such as stock options, and the effect from unvested restricted stock awards and restricted stock units 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 Company’s unvested restricted stock awards entitle the holder to participate in dividends and earnings of the Company, and, if the Company were to recognize net income, it would have to use the two-class method to calculate earnings per share. The two-class method is not applicable during periods with a net loss, as the holders of the unvested restricted stock awards have no obligation to fund losses.

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:

	June 30,
	2022		2021
Unvested restricted stock awards		356,432		841,965
Unvested restricted stock units		170,000		25,000
Stock options		8,915,289		6,769,438
		9,441,721		7,636,403

Amounts in the above table reflect the common stock equivalents.

Recently Issued Accounting Pronouncements

Emerging Growth Company Status

The Company is an emerging growth company, as defined in the Jumpstart Our Business Startups Act of 2012 (the “JOBS Act”). Under the JOBS Act, emerging growth companies can delay adopting new or revised accounting standards issued subsequent to the enactment of the JOBS Act, until such time as those standards apply to private companies. The Company has elected to use this extended transition period for complying with new or revised accounting standards that have different effective dates for public and private companies until the earlier of the date that it (i) is no longer an emerging growth company or (ii) affirmatively and irrevocably opts out of the extended transition period provided in the JOBS Act. As a result, these unaudited interim financial statements may not be comparable to companies that comply with the new or revised accounting pronouncements as of public company effective dates.

Recently Adopted Accounting Pronouncements

In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments-Credit Losses: Measurement of Credit Losses on Financial Instruments” which has subsequently been amended by ASU No. 2019-04, ASU No. 2019-05, ASU No. 2019-10, ASU No. 2019-11, and ASU No. 2020-03 (“ASU 2016-03”). This guidance replaces the incurred loss impairment methodology under current U.S. GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. The Company early adopted this standard as of January 1, 2022 using a modified retrospective approach. It did not have a material impact on the Company’s financial statements and related disclosures.

In November 2021, the FASB issued ASU No. 2021-10, “Government Assistance: Disclosures by Business Entities about Government Assistance”. The amendments in this Update improve financial reporting by requiring disclosures that increase the transparency of transactions with a government. The amendments require the following annual disclosures about transactions with a government that are accounted for by applying a grant or contribution accounting model by analogy (i) the type of transaction (ii) the accounting for the transaction, and (iii) the effect of the transaction on the entity’s financial statements. The Company adopted this standard as of January 1, 2022 using a prospective approach and it did not have a material impact on the Company’s financial statements and related disclosures.

Marketable Securities

6 Months Ended

Jun. 30, 2022

Investments Debt And Equity Securities [Abstract]

Marketable Securities

4. Marketable Securities

The following is a summary of the Company’s marketable securities.

(in thousands)	Amortized Cost		Gross unrealized gain		Gross unrealized loss			Fair Value
June 30, 2022:
Corporate debt securities	$	184,045	$	20	$	(2,289	)	$	181,776
Commercial paper		13,848		—		(25	)		13,823
Total	$	197,893	$	20	$	(2,314	)	$	195,599

December 31, 2021
Corporate debt securities	$	193,798	$	1	$	(696	)	$	193,103
Commercial paper		66,318		1		(17	)		66,302
Total	$	260,116	$	2	$	(713	)	$	259,405

The Company’s marketable securities generally have contractual maturity dates of 16 months or less. The Company believes that any unrealized losses associated with the decline in value of its securities is temporary, is primarily related to market factors and believes that it is more likely than not that it will be able to hold its debt securities to maturity. Therefore, the Company anticipates a full recovery of the amortized cost basis of its debt securities at maturity and an allowance for credit losses was not recognized.

Fair Value of Financial Instruments

6 Months Ended

Jun. 30, 2022

Fair Value Disclosures [Abstract]

Fair Value of Financial Instruments

5. Fair Value of Financial Instruments

Fair value is the price that could be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. Fair value determination in accordance with applicable accounting guidance requires that a number of significant judgments be made. Additionally, fair value is used on a nonrecurring basis to evaluate assets for impairment or as required for disclosure purposes by applicable accounting guidance on disclosures about fair value of financial instruments. Depending on the nature of the assets and liabilities, various valuation techniques and assumptions are used when estimating fair value. The Company follows the provisions of ASC 820, for financial assets and liabilities measured on a recurring basis. The guidance requires fair value measurements be classified and disclosed in one of the following three categories:

•

Level 1: Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities.

•

Level 2: Quoted prices in markets that are not active, or inputs which are observable, either directly or indirectly, for substantially the full term of the asset or liabilities.

•

Level 3: Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (i.e., supported by little or no market activity).

The following fair value hierarchy table presents information about the Company’s assets and liabilities measured at fair value on a recurring basis:

	Fair value measurement at reporting date using
(in thousands)	Quoted prices in active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
June 30, 2022:
Assets:
Cash equivalents (Money Market Funds)	$	47,958	$	—	$	—
Marketable securities
Corporate debt securities		—		181,776		—
Commercial paper		—		13,823		—
Total	$	47,958	$	195,599	$	—

December 31, 2021:
Assets:
Cash equivalents (Money Market Funds)	$	30,520	$	—	$	—
Marketable securities
Corporate debt securities		—		193,103		—
Commercial paper		—		66,302		—
Total	$	30,520	$	259,405	$	—

- Definition

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

+ References + Details

Accrued Expenses and Other Current Liabilities

6 Months Ended

Jun. 30, 2022

Payables And Accruals [Abstract]

Accrued Expenses and Other Current Liabilities

6. Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following:

(in thousands)	June 30, 2022		December 31, 2021
Compensation and related benefits	$	4,031	$	4,919
Research and development		3,396		4,615
Other		289		87
	$	7,716	$	9,621

Common Stock

6 Months Ended

Jun. 30, 2022

Equity [Abstract]

Common Stock

7. Common Stock

Common Stock Offering

In January 2021, the Company sold 2,875,000 shares of its common stock at a public offering price of $60.00 per share. The Company received net proceeds of $161.4 million after deducting underwriting discounts, commissions, and other offering expenses paid by the Company.

The Company has two classes of common stock; “voting common stock” and “non-voting common stock.” The holders of the voting common stock are entitled to one vote for each share of voting common stock held at all meetings of stockholders. Except as otherwise required by law, the holders of non-voting common stock shall not be entitled to vote at any meetings of stockholders (or written actions in lieu of meetings) and the shares of non-voting common stock shall not be included in determining the number of shares voting or entitled to vote on any matter. Unless required by law, there shall be no cumulative voting. Any holder of non-voting common stock may elect to convert each share of non-voting common stock into one fully paid and non-assessable share of voting common stock at any time by providing written notice to the Company; provided that as a result of such conversion, such holder, together with its affiliates and any members of a Schedule 13(d) group with such holder, would not beneficially own in excess of 9.99% of the Company’s common stock immediately prior to and following such conversion, unless otherwise as expressly provided for in the Company’s restated certificate of incorporation. However, this ownership limitation may be increased (not to exceed 19.99%) or decreased to any other percentage designated by such holder of non-voting common stock upon 61 days’ notice to the Company.

- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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+ Details

Commitments

6 Months Ended

Jun. 30, 2022

Commitments And Contingencies Disclosure [Abstract]

Commitments

8. Commitments

Leases

The Company leases office and laboratory space in Wilmington, Delaware under a noncancelable lease (the “Lease”). During the first quarter of 2022, the Lease was amended to allow the Company the option to renew the Lease for two 6-month periods and the Company exercised its option to renew the lease for an additional 6 months until June 30, 2023. The second option to extend the Lease for an additional 6 months was not recognized as part of the Company’s measurement of the right-of-use asset and operating lease liability as of June 30, 2022. The discount rate used to account for the Company’s operating lease under ASC 842 is the Company’s estimated incremental borrowing rate of 6.0%.

Rent expense for the three months ended June 30, 2022 and 2021 was $0.6 million and $0.3 million, respectively. Rent expense for the six months ended June 30, 2022 and 2021 was $1.1 million and $0.7 million, respectively.

Future minimum annual lease payments under the Lease at June 30, 2022 are as follows:

(in thousands)
2022 (remaining)	$	918
2023		964
Total undiscounted lease payments		1,882
Less imputed interest		(60	)
Current and noncurrent lease liability	$	1,822

In August 2022, we entered into an amendment (the “Lease Amendment”) to the lease agreement for office and lab space at Chestnut Run Plaza in Wilmington, Delaware (the “Chestnut Run Lease”). The Chestnut Run Lease has a commencement date of the earlier of (i) the Landlord Work Substantial Completion Date (as such term is defined in the Chestnut Run Lease), or (ii) the date the Company takes possession of the premises for the conduct of the Company’s business (the “Commencement Date”). The Chestnut Run Lease premises includes approximately 81,000 rentable square feet, located at Chestnut Run Plaza in Wilmington, Delaware (the Premises). Upon the Commencement Date, the Company will recognize a right-of-use asset and operating lease liability in accordance with ASC 842. The Chestnut Run Lease has an initial term of 162 months with 3 five-year extension options and certain expansion rights. The Lease Amendment increases the monthly base rent payments due over the initial term of the Chestnut Run Lease to approximately $42.6 million. The estimated rent payments related to the Chestnut Run Lease are as follows:

(in thousands)
2022 (remaining 6 months)	$	—
2023		—
2024		2,370
2025		2,943
2026		3,016
2027		3,092
Thereafter		31,216

The Company paid a security deposit for the Chestnut Run Lease in the form of a letter of credit of $4.0 million, which is included in the balance sheet as restricted cash as of June 30, 2022. The security deposit may be reduced to $0.5 million over time in accordance with the terms of the Chestnut Run Lease.

In connection with the Company’s expansion of operations in the State of Delaware, the Company was approved for a grant from the State of Delaware in 2021 that will provide up to $5.5 million in reimbursements over three years for the development of lab space in addition to increasing jobs in Delaware to meet specific targeted levels through 2023. During the first quarter of 2022, the Company received cash of $2.4 million from the grant for the development of lab space. The Company has deferred the recognition of these grant funds as they relate to capitalized costs and has classified them as long-term liabilities on the balance sheet. The Company will recognize the grant funds in other income as grant income over the useful life of the related assets. If, after two years from the disbursement date, the incurred costs for lab space are less than the $2.4 million received, the Company is required to pay back the difference between total funds received and allowable costs incurred. Additionally, if the Company leaves the State of Delaware within five years of the disbursement, the Company is required to return an amount equal to the amount of grant funds disbursed on a pro-rated basis. During the first quarter of 2022, the Company also received cash of $0.3 million for satisfying the first performance benchmark measurement. The Company recognized this in other income, net on the statement of operations and comprehensive loss.

To the extent the Company’s employee headcount is fewer than the performance benchmark, the Company is required to repay the amount of grant funds received for the number of employees below the benchmark.

Employment Agreements

The Company entered into employment agreements with key personnel providing for compensation and severance in certain circumstances, as defined in the respective employment agreements.

401(k) Defined Contribution Plan

The Company sponsors a 401(k) defined‑contribution plan covering all employees. Participants are permitted to contribute up to 100% of their eligible annual pretax compensation up to an established federal limit on aggregate participant contributions. The Company provides a safe harbor match with a maximum amount of 3% of the participant’s compensation. For both the three months ended June 30, 2022 and 2021, the Company made matching contributions of $0.1 million. For both the six months ended June 30, 2022 and 2021, the Company made matching contributions of $0.3 million.

Research Collaboration Agreement

In September 2021, the Company entered into a research collaboration agreement estimated to last for approximately one year (the “Darwin Health Agreement”) with Darwin Health, Inc. (“DarwinHealth”). Under the terms of the Darwin Health Agreement, DarwinHealth will utilize their drug discovery technologies and certified methodologies in precision oncology to advance and accelerate clinical development for certain of the Company’s programs across a broad range of tumor subtypes. The Company will pay DarwinHealth a total of $3.0 million in three equal installments over the one-year term (the “Research Term”) to fund the research and, if the Company adopts any of DarwinHealth’s development ideas, the Company will be responsible for the development, manufacturing, and commercialization of any such products. In addition to research funding, DarwinHealth is eligible to receive future research, development and regulatory milestones of up to $3.0 million for each product candidate and is also eligible to receive tiered royalties in the low single digits on net sales of each product developed using DarwinHealth’s development technologies or methods. However, within eighteen-months following the Research Term, the Company, in its sole discretion, may notify DarwinHealth that it will not utilize its development ideas and will be entitled to receive a refund of $0.5 million.

Other Research and Development Arrangements

The Company enters into agreements with contract research organizations (“CROs”) to assist in the performance of research and development activities. Expenditures to CROs will represent a significant cost in clinical development for the Company.

Stock-Based Compensation

6 Months Ended

Jun. 30, 2022

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock-Based Compensation

9. Stock-Based Compensation

The Company has two equity incentive plans: the 2016 Equity Incentive Plan, as amended, and the 2020 Equity Incentive Plan. New awards can only be granted under the 2020 Equity Incentive Plan (the “Plan”) and as of June 30, 2022, 5,708,289 shares were available for future grants. The number of shares of the Company’s common stock that may be issued pursuant to rights granted under the Plan shall automatically increase on January 1st of each year, commencing on January 1, 2021, and continuing for ten years, in an amount equal to five percent of the total number of shares of the Company’s common stock outstanding on December 31st of the preceding calendar year, subject to the discretion of the board of directors or compensation committee to determine a lesser number of shares shall be added for such year. The Plan provides for the granting of common stock, incentive stock options, nonqualified stock options, restricted stock awards, restricted stock units and/or stock appreciation rights to employees, directors, and other persons, as determined by the Company’s board of directors. The Company’s stock options vest based on the terms in each award agreement, generally over four-year periods with 25% of options vesting after 1 year and then monthly thereafter, and have a term of ten years.

The Company measures stock-based awards at their grant-date fair value and records compensation expense on a straight-line basis over the vesting period of the awards. The Company recorded stock-based compensation expense in the following expense categories in its accompanying statements of operations:

	Three Months Ended June 30,				Six Months Ended June 30,
(in thousands)	2022		2021		2022		2021
Research and development	$	2,472	$	2,203	$	5,672	$	4,043
General and administrative		3,556		2,034		7,185		4,080
	$	6,028	$	4,237	$	12,857	$	8,123

Stock Options

The following table summarizes stock option activity for the periods indicated:

	Number of shares			Weighted average exercise price per share		Weighted average remaining contractual term (years)
Outstanding at January 1, 2022		7,179,482		$	15.36		8.66
Granted		2,705,609		$	8.32
Exercised		(124,285	)	$	1.70
Forfeited		(845,517	)	$	18.06
Outstanding at June 30, 2022		8,915,289		$	13.16		8.60
Exercisable at June 30, 2022		2,738,389		$	9.81		7.71

At June 30, 2022, the aggregate intrinsic value of outstanding options and exercisable options was $7.7 million and $4.9 million, respectively.

The following table summarizes information about stock options outstanding at June 30, 2022 under the Plan:

	Options Outstanding						Options Exercisable
Range of Exercise Prices	Number Outstanding		Weighted Average Remaining Contractual Life (in years)		Weighted Average Exercise Price		Number Exercisable		Weighted Average Exercise Price
$0.31 - $3.05		2,109,347		7.26	$	1.80		1,414,546	$	1.76
$3.06 - $10.34		1,068,193		9.88		4.84		4,500		10.09
$10.35 - $11.72		1,447,250		9.63		10.58		—		0.00
$11.73 - $13.04		2,253,228		8.17		12.85		1,031,129		12.85
$13.05 - $88.98		2,037,271		9.05		31.48		288,214		38.39
		8,915,289						2,738,389

The weighted-average grant date fair value of options granted was $6.00 and $38.31 per share for the six months ended June 30, 2022 and 2021, respectively. The aggregate intrinsic value of options exercised was $0.7 million for the six months ended June 30, 2022. The Company recorded stock-based compensation expense of $5.7 million and $4.2 million for the three months ended June 30, 2022 and 2021, respectively, related to stock options. The Company recorded stock-based compensation expense of $12.2 million and $7.7 million for the six months ended June 30, 2022 and 2021, respectively, related to stock options. As of June 30, 2022, the total unrecognized compensation expense related to unvested stock option awards was $61.8 million, which the Company expects to recognize over a weighted-average period of 2.79 years.

The fair value of each option was estimated on the date of grant using the weighted average assumptions in the table below:

	Six months ended June 30,
	2022			2021
Expected volatility		84.82	%		115.05	%
Risk-free interest rate		2.39	%		0.93	%
Expected life (in years)		6.01			5.91
Expected dividend yield		—			—

Restricted Stock Awards and Units

The Company issues restricted stock awards (“RSA”) to employees that generally vest over a four-year period with 25% of awards vesting after one year and then monthly thereafter. Any unvested shares will be forfeited upon termination of services. The fair value of an RSA is equal to the fair market value price of the Company’s common stock on the date of grant. RSA expense is recorded on a straight-line basis over the vesting period.

The following table summarizes activity related to RSA stock-based payment awards:

	Number of shares			Weighted-average grant date fair value
Unvested balance at January 1, 2022		611,608		$	2.29
Vested		(231,760	)	$	1.88
Forfeited		(23,416	)	$	1.89
Unvested balance at June 30, 2022		356,432		$	2.58

The Company recorded stock-based compensation expense of $0.2 million for both the three months ended June 30, 2022 and 2021 related to RSAs. The Company recorded stock-based compensation expense of $0.4 million for both the six months ended June 30, 2022 and 2021, related to RSAs. As of June 30, 2022, the total unrecognized expense related to all RSAs was $0.9 million, which the Company expects to recognize over a weighted-average period of 1.45 years.

The Company granted restricted stock units (“RSU”) to employees that generally vest over a four-year period with 25% of awards vesting after one year and then quarterly thereafter. Any unvested units will be forfeited upon termination of services.

The following table summarizes activity related to RSU stock-based payment awards:

	Number of shares		Weighted-average grant date fair value
Unvested balance at January 1, 2022		20,000	$	18.32
Granted		150,000	$	4.86
Unvested balance at June 30, 2022		170,000	$	6.44

The Company recorded stock-based compensation expense of $58 thousand and $82 thousand for the three and six months ended June 30, 2022, respectively, related to RSUs. At June 30, 2022 the total unrecognized expense related to the RSUs was $1.0 million, which the Company expects to recognize over 3.61 years.

Employee Stock Purchase Plan

The Company has an Employee Stock Purchase Plan (the “ESPP”), which, as of June 30, 2022, had 1,339,285 shares of common stock reserved for future issuance. The number of shares of the Company’s common stock that may be issued pursuant to rights granted under the ESPP shall automatically increase on January 1st of each year and continuing for ten years beginning in 2021, in an amount equal to one percent of the total number of shares of all classes of the Company’s common stock outstanding on December 31st of the preceding calendar year, subject to the discretion of the board of directors or compensation committee to determine a lesser number of shares shall be added for such year. On January 1, 2022, 476,023 shares were added to the ESPP.

Under the ESPP, eligible employees can purchase the Company’s common stock through accumulated payroll deductions at such times as are established by the compensation committee. Eligible employees may purchase the Company’s common stock at 85% of the lower of the fair market value of the Company’s common stock on the first day of the offering period or on the last day of the offering period. Eligible employees may contribute up to 15% of their eligible compensation. Under the ESPP, a participant may not accrue rights to purchase more than $25,000 worth of the Company’s common stock for each calendar year in which such right is outstanding.

The ESPP is considered compensatory under the FASB stock compensation rules. Accordingly, share-based compensation expense is determined based on the option’s grant-date fair value as estimated by applying the Black Scholes option-pricing model and is recognized over the withholding period. The Company recognized share-based compensation expense of $0.1 million and $0.2 million for the three and six months ended June 30, 2022, respectively, related to the ESPP. There was no share-based compensation expense recognized in 2021 related to the ESPP.

Summary of Significant Accounting Policies (Policies)

6 Months Ended

Jun. 30, 2022

Accounting Policies [Abstract]

Basis of presentation

Use of estimates

Income taxes

Cash, Cash Equivalents and Restricted Cash

Cash, Cash Equivalents and Restricted cash

Restricted cash comprises a letter of credit for the benefit of the landlord in connection with the Company’s Chestnut Run Lease. See Note 8 for further details.

The following table provides a reconciliation of cash and cash equivalents and restricted cash reported within the balance sheet that total to the amounts shown in the statement of cash flows:

(in thousands)	June 30, 2022		December 31, 2021
Cash and cash equivalents	$	50,706	$	31,828
Restricted cash		4,044		4,044
Total cash, cash equivalents, and restricted cash shown in statement of cash flows	$	54,750	$	35,872

Marketable Securities

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:

	June 30,
	2022		2021
Unvested restricted stock awards		356,432		841,965
Unvested restricted stock units		170,000		25,000
Stock options		8,915,289		6,769,438
		9,441,721		7,636,403

Amounts in the above table reflect the common stock equivalents.

Recently Issued Accounting Pronouncements

Emerging Growth Company Status

Recently Adopted Accounting Pronouncements

- Definition

Disclosure of accounting policy for income taxes, which may include its accounting policies for recognizing and measuring deferred tax assets and liabilities and related valuation allowances, recognizing investment tax credits, operating loss carryforwards, tax credit carryforwards, and other carryforwards, methodologies for determining its effective income tax rate and the characterization of interest and penalties in the financial statements.

+ References + Details

Summary of Significant Accounting Policies (Tables)

6 Months Ended

Jun. 30, 2022

Accounting Policies [Abstract]

Schedule of Reconciliation of Cash and Cash Equivalents and Restricted Cash

The following table provides a reconciliation of cash and cash equivalents and restricted cash reported within the balance sheet that total to the amounts shown in the statement of cash flows:

(in thousands)	June 30, 2022		December 31, 2021
Cash and cash equivalents	$	50,706	$	31,828
Restricted cash		4,044		4,044
Total cash, cash equivalents, and restricted cash shown in statement of cash flows	$	54,750	$	35,872

Schedule of Potentially Dilutive Securities Excluded from Computation of Diluted Weighted-average Shares of Common Stock Outstanding

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:

	June 30,
	2022		2021
Unvested restricted stock awards		356,432		841,965
Unvested restricted stock units		170,000		25,000
Stock options		8,915,289		6,769,438
		9,441,721		7,636,403

Marketable Securities (Tables)

6 Months Ended

Jun. 30, 2022

Investments Debt And Equity Securities [Abstract]

Schedule of Marketable Securities

The following is a summary of the Company’s marketable securities.

(in thousands)	Amortized Cost		Gross unrealized gain		Gross unrealized loss			Fair Value
June 30, 2022:
Corporate debt securities	$	184,045	$	20	$	(2,289	)	$	181,776
Commercial paper		13,848		—		(25	)		13,823
Total	$	197,893	$	20	$	(2,314	)	$	195,599

December 31, 2021
Corporate debt securities	$	193,798	$	1	$	(696	)	$	193,103
Commercial paper		66,318		1		(17	)		66,302
Total	$	260,116	$	2	$	(713	)	$	259,405

Fair Value of Financial Instruments (Tables)

6 Months Ended

Jun. 30, 2022

Fair Value Disclosures [Abstract]

Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis

The following fair value hierarchy table presents information about the Company’s assets and liabilities measured at fair value on a recurring basis:

	Fair value measurement at reporting date using
(in thousands)	Quoted prices in active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
June 30, 2022:
Assets:
Cash equivalents (Money Market Funds)	$	47,958	$	—	$	—
Marketable securities
Corporate debt securities		—		181,776		—
Commercial paper		—		13,823		—
Total	$	47,958	$	195,599	$	—

December 31, 2021:
Assets:
Cash equivalents (Money Market Funds)	$	30,520	$	—	$	—
Marketable securities
Corporate debt securities		—		193,103		—
Commercial paper		—		66,302		—
Total	$	30,520	$	259,405	$	—

Accrued Expenses and Other Current Liabilities (Tables)

6 Months Ended

Jun. 30, 2022

Payables And Accruals [Abstract]

Schedule of Accrued Expenses and Other Current Liabilities

6. Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following:

(in thousands)	June 30, 2022		December 31, 2021
Compensation and related benefits	$	4,031	$	4,919
Research and development		3,396		4,615
Other		289		87
	$	7,716	$	9,621

Commitments (Tables)

6 Months Ended

Jun. 30, 2022

Operating Lease, until June 30, 2023

Schedule of Future Minimum Annual Lease Payments Under Lease

Future minimum annual lease payments under the Lease at June 30, 2022 are as follows:

(in thousands)
2022 (remaining)	$	918
2023		964
Total undiscounted lease payments		1,882
Less imputed interest		(60	)
Current and noncurrent lease liability	$	1,822

Chestnut Run Lease

Schedule of Future Minimum Annual Lease Payments Under Lease

The estimated rent payments related to the Chestnut Run Lease are as follows:

(in thousands)
2022 (remaining 6 months)	$	—
2023		—
2024		2,370
2025		2,943
2026		3,016
2027		3,092
Thereafter		31,216

Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2022

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Schedule of Stock-Based Compensation Expense Recorded in Statements of Operations

The Company recorded stock-based compensation expense in the following expense categories in its accompanying statements of operations:

	Three Months Ended June 30,				Six Months Ended June 30,
(in thousands)	2022		2021		2022		2021
Research and development	$	2,472	$	2,203	$	5,672	$	4,043
General and administrative		3,556		2,034		7,185		4,080
	$	6,028	$	4,237	$	12,857	$	8,123

Summary of Stock Option Activity

The following table summarizes stock option activity for the periods indicated:

	Number of shares			Weighted average exercise price per share		Weighted average remaining contractual term (years)
Outstanding at January 1, 2022		7,179,482		$	15.36		8.66
Granted		2,705,609		$	8.32
Exercised		(124,285	)	$	1.70
Forfeited		(845,517	)	$	18.06
Outstanding at June 30, 2022		8,915,289		$	13.16		8.60
Exercisable at June 30, 2022		2,738,389		$	9.81		7.71

Summary of Information about Stock Options Outstanding

The following table summarizes information about stock options outstanding at June 30, 2022 under the Plan:

	Options Outstanding						Options Exercisable
Range of Exercise Prices	Number Outstanding		Weighted Average Remaining Contractual Life (in years)		Weighted Average Exercise Price		Number Exercisable		Weighted Average Exercise Price
$0.31 - $3.05		2,109,347		7.26	$	1.80		1,414,546	$	1.76
$3.06 - $10.34		1,068,193		9.88		4.84		4,500		10.09
$10.35 - $11.72		1,447,250		9.63		10.58		—		0.00
$11.73 - $13.04		2,253,228		8.17		12.85		1,031,129		12.85
$13.05 - $88.98		2,037,271		9.05		31.48		288,214		38.39
		8,915,289						2,738,389

Schedule of Fair Value of Each Option Estimated on Date of Grant Using Weighted Average Assumptions

The fair value of each option was estimated on the date of grant using the weighted average assumptions in the table below:

	Six months ended June 30,
	2022			2021
Expected volatility		84.82	%		115.05	%
Risk-free interest rate		2.39	%		0.93	%
Expected life (in years)		6.01			5.91
Expected dividend yield		—			—

Summary of Activity related to RSA Stock-Based Payment Awards

The following table summarizes activity related to RSA stock-based payment awards:

	Number of shares			Weighted-average grant date fair value
Unvested balance at January 1, 2022		611,608		$	2.29
Vested		(231,760	)	$	1.88
Forfeited		(23,416	)	$	1.89
Unvested balance at June 30, 2022		356,432		$	2.58

Summary of Activity related to RSU Stock-Based Payment Awards

The following table summarizes activity related to RSU stock-based payment awards:

	Number of shares		Weighted-average grant date fair value
Unvested balance at January 1, 2022		20,000	$	18.32
Granted		150,000	$	4.86
Unvested balance at June 30, 2022		170,000	$	6.44

Risks and Liquidity - Additional Information (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Risks And Liquidity [Abstract]
Accumulated deficit	$ (275,959)	$ (219,120)

Summary of Significant Accounting Policies - Schedule of Reconciliation of Cash and Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Accounting Policies [Abstract]
Cash and cash equivalents	$ 50,706	$ 31,828
Restricted cash	4,044	4,044
Total cash, cash equivalents, and restricted cash shown in statement of cash flows	$ 54,750	$ 35,872

Summary of Significant Accounting Policies - Schedule of Potentially Dilutive Securities Excluded from Computation of Diluted Weighted-average Shares of Common Stock Outstanding (Details) - shares	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	9,441,721	7,636,403
Unvested Restricted Stock Awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	356,432	841,965
Unvested Restricted Stock Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	170,000	25,000
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	8,915,289	6,769,438

Summary of Significant Accounting Policies - Additional Information (Details)	Jun. 30, 2022
ASU 2016-13
Summary of Significant Accounting Policies [Line Items]
Change in accounting principle, ASU, adopted	true
Change in accounting principle, ASU, adoption date	Jan. 01, 2022
Change in accounting principle, ASU, immaterial effect	true
ASU 2021-10
Summary of Significant Accounting Policies [Line Items]
Change in accounting principle, ASU, adopted	true
Change in accounting principle, ASU, adoption date	Jan. 01, 2022
Change in accounting principle, ASU, immaterial effect	true

- Definition

Indicates (true false) whether accounting standards update was adopted.

+ References

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- Definition

Date accounting standards update was adopted, in YYYY-MM-DD format.

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+ Details

Marketable Securities - Schedule of Marketable Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Marketable Securities [Line Items]
Marketable securities, Amortized cost	$ 197,893	$ 260,116
Marketable securities, Gross unrealized gain	20	2
Marketable securities, Gross unrealized loss	(2,314)	(713)
Marketable securities, Fair value	195,599	259,405
Corporate Debt Securities
Marketable Securities [Line Items]
Marketable securities, Amortized cost	184,045	193,798
Marketable securities, Gross unrealized gain	20	1
Marketable securities, Gross unrealized loss	(2,289)	(696)
Marketable securities, Fair value	181,776	193,103
Commercial Paper
Marketable Securities [Line Items]
Marketable securities, Amortized cost	13,848	66,318
Marketable securities, Gross unrealized gain		1
Marketable securities, Gross unrealized loss	(25)	(17)
Marketable securities, Fair value	$ 13,823	$ 66,302

Fair Value of Financial Instruments - Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value measurement, recurring basis, assets	$ 47,958	$ 30,520
Quoted Prices in Active Markets for Identical Assets (Level 1) \| Money Market Funds
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value measurement, recurring basis, assets	47,958	30,520
Significant other observable inputs (Level 2)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value measurement, recurring basis, assets	195,599	259,405
Significant other observable inputs (Level 2) \| Corporate Debt Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value measurement, recurring basis, assets	181,776	193,103
Significant other observable inputs (Level 2) \| Commercial Paper
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value measurement, recurring basis, assets	$ 13,823	$ 66,302

Accrued Expenses and Other Current Liabilities - Summary of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Payables And Accruals [Abstract]
Compensation and related benefits	$ 4,031	$ 4,919
Research and development	3,396	4,615
Other	289	87
Accrued expenses and other current liabilities	$ 7,716	$ 9,621

Common Stock - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	6 Months Ended
	Jan. 31, 2021	Jun. 30, 2022	Jun. 30, 2021
Class Of Stock [Line Items]
Net proceeds from issuance of common stock			$ 161,424
Common Stock
Class Of Stock [Line Items]
Common stock, voting rights		The holders of the voting common stock are entitled to one vote for each share of voting common stock held at all meetings of stockholders
Common Stock \| Minimum
Class Of Stock [Line Items]
Beneficial ownership percentage		9.99%
Common Stock \| Maximum
Class Of Stock [Line Items]
Beneficial ownership percentage		19.99%
Common Stock \| Follow-on Offering
Class Of Stock [Line Items]
Number of shares sold	2,875,000
Public offering price	$ 60.00
Net proceeds from issuance of common stock	$ 161,400

Commitments - Additional Information (Details) $ in Millions	1 Months Ended		3 Months Ended			6 Months Ended
	Aug. 31, 2022 USD ($) ft² Extension	Sep. 30, 2021 USD ($) Installment	Jun. 30, 2022 USD ($)	Mar. 31, 2022 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)
Other Commitments [Line Items]
Lease renewal period			6 months			6 months
Operating lease estimated incremental borrowing rate percent						6.00%
Lessee, operating lease, option to extend						The second option to extend the Lease for an additional 6 months was not recognized as part of the Company’s measurement of the right-of-use asset and operating lease liability as of June 30, 2022
Rent expense			$ 0.6		$ 0.3	$ 1.1	$ 0.7
Reimbursements for development of lab space						$ 5.5
Reimbursements for development of lab space period						3 years
Reimbursements for development of lab space expiration year						2023
Grant for development of lab space						$ 2.4
Received cash for satisfying performance benchmark measurement				$ 0.3
Defined contribution plan, maximum annual contributions per employee, percent						100.00%
Defined contribution plan, employer matching contribution, percent of employee's gross pay						3.00%
Defined contribution plan, employer discretionary contribution amount			$ 0.1		$ 0.1	$ 0.3	$ 0.3
DarwinHealth
Other Commitments [Line Items]
Estimated years of research collaboration agreement		1 year
Estimated amount of payment over a agreement term		$ 3.0
Research term		1 year
Number of equal instalments \| Installment		3
Grace period following research term for potential refund		18 months
Potential refund receivable from agreement		$ 0.5
Maximum
Other Commitments [Line Items]
Disbursement incurred costs for lab space						$ 2.4
Maximum \| DarwinHealth
Other Commitments [Line Items]
Agreement is eligible to receive payment in future research, development and regulatory milestones		$ 3.0
Operating Lease, until June 30, 2023
Other Commitments [Line Items]
Lease renewal period			6 months			6 months
Chestnut Run Lease \| Letter of Credit
Other Commitments [Line Items]
Security deposit			$ 4.0			$ 4.0
Chestnut Run Lease \| Scenario Forecast
Other Commitments [Line Items]
Lease renewal period	5 years
Area of lease premises \| ft²	81,000
Initial term of lease	162 months
Number of lease extensions \| Extension	3
Aggregate estimated rent payments due over initial term	$ 42.6
Chestnut Run Lease \| Pro Forma \| Letter of Credit
Other Commitments [Line Items]
Security deposit			$ 0.5			$ 0.5

Commitments - Schedule of Future Minimum Annual Lease Payments Under Lease (Details) $ in Thousands	Jun. 30, 2022 USD ($)
Operating Lease, until June 30, 2023
Lease Liability [Line Items]
2022 (remaining)	$ 918
2023	964
Total undiscounted lease payments	1,882
Less imputed interest	(60)
Current and noncurrent lease liability	1,822
Chestnut Run Lease
Lease Liability [Line Items]
2024	2,370
2025	2,943
2026	3,016
2027	3,092
Thereafter	$ 31,216

Stock-Based Compensation - Additional Information (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2022 USD ($) $ / shares shares	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($) Plan $ / shares shares	Jun. 30, 2021 USD ($) $ / shares	Jan. 01, 2022 shares	Dec. 31, 2021 $ / shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of equity incentive plans \| Plan			2
Aggregate intrinsic value of outstanding options	$ 7,700,000		$ 7,700,000
Aggregate intrinsic value of exercisable options	4,900,000		4,900,000
Stock-based compensation expense	6,028,000	$ 4,237,000	$ 12,857,000	$ 8,123,000
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average grant date fair value of options granted \| $ / shares			$ 6.00	$ 38.31
Aggregate intrinsic value of options exercised			$ 700,000
Stock-based compensation expense	5,700,000	4,200,000	12,200,000	$ 7,700,000
Total unrecognized compensation expense related to unvested stock option awards	61,800,000		$ 61,800,000
Total unrecognized compensation expense, weighted-average period			2 years 9 months 14 days
Unvested Restricted Stock Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting period			4 years
Stock-based compensation expense	200,000	200,000	$ 400,000	400,000
Total unrecognized compensation expense, weighted-average period			1 year 5 months 12 days
Share-based payment arrangement, nonvested award, unrecognized expense	$ 900,000		$ 900,000
weighted-average grant date fair value \| $ / shares	$ 2.58		$ 2.58			$ 2.29
Number of shares, Forfeited \| shares			23,416
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting period			4 years
Stock-based compensation expense	$ 58,000		$ 82,000
Total unrecognized compensation expense, weighted-average period			3 years 7 months 9 days
Share-based payment arrangement, nonvested award, unrecognized expense	$ 1,000,000.0		$ 1,000,000.0
weighted-average grant date fair value \| $ / shares	$ 6.44		$ 6.44			$ 18.32
Number of shares, Granted \| shares			150,000
2020 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares available for future grants \| shares	5,708,289		5,708,289
Terms of award			The Company’s stock options vest based on the terms in each award agreement, generally over four-year periods with 25% of options vesting after 1 year and then monthly thereafter, and have a term of ten years.
Award term			10 years
Percentage of shares outstanding used to calculate annual increase in number of shares that can be issued			5.00%
2020 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares available for future grants \| shares	1,339,285		1,339,285
Percentage of shares outstanding used to calculate annual increase in number of shares that can be issued			1.00%
Stock-based compensation expense	$ 100,000	$ 0		$ 0
Number of shares authorized \| shares					476,023
Eligible employees purchase common stock percentage of lower of fair market value			85.00%
Participants accrue rights to purchase maximum common stock amount			$ 25,000
Maximum \| 2020 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting period			4 years
Maximum \| 2020 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Eligible employees contribution percentage			15.00%
Minimum \| 2020 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting period			1 year
Vesting After One Year \| Unvested Restricted Stock Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of stock options vested			25.00%
Vesting After One Year \| Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of stock options vested			25.00%
Vesting After One Year \| 2020 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of stock options vested			25.00%

Stock-Based Compensation - Schedule of Stock-Based Compensation Expense Recorded in Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 6,028	$ 4,237	$ 12,857	$ 8,123
Research and Development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	2,472	2,203	5,672	4,043
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 3,556	$ 2,034	$ 7,185	$ 4,080

Stock-Based Compensation - Summary of Stock Option Activity (Details) - $ / shares	6 Months Ended	12 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of shares, Outstanding at beginning of period	7,179,482
Number of shares, Granted	2,705,609
Number of shares, Exercised	(124,285)
Number of shares, Forfeited	(845,517)
Number of shares, Outstanding at end of period	8,915,289	7,179,482
Number of shares, Exercisable at June 30, 2022	2,738,389
Weighted average exercise price per share, Outstanding at beginning of period	$ 15.36
Weighted average exercise price per share, Granted	8.32
Weighted average exercise price per share, Exercised	1.70
Weighted average exercise price per share, Forfeited	18.06
Weighted average exercise price per share, Outstanding at end of period	13.16	$ 15.36
Weighted average exercise price per share, Exercisable at June 30,2022	$ 9.81
Weighted average remaining contractual term (years), Outstanding	8 years 7 months 6 days	8 years 7 months 28 days
Weighted average remaining contractual term (years), Exercisable	7 years 8 months 15 days

Stock-Based Compensation - Summary of Information about Stock Options Outstanding (Details)	6 Months Ended
	Jun. 30, 2022 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options Outstanding, Number \| shares	8,915,289
Options Exercisable, Number Exercisable \| shares	2,738,389
$0.31 - $3.05
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Range of Exercise Prices, Minimum	$ 0.31
Range of Exercise Prices, Maximum	$ 3.05
Options Outstanding, Number \| shares	2,109,347
Options Outstanding, Weighted Average Remaining Contractual Life (in years)	7 years 3 months 3 days
Options Outstanding, Weighted Average Exercise Price	$ 1.80
Options Exercisable, Number Exercisable \| shares	1,414,546
Options Exercisable, Weighted Average Exercise Price	$ 1.76
$3.06 - $10.34
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Range of Exercise Prices, Minimum	3.06
Range of Exercise Prices, Maximum	$ 10.34
Options Outstanding, Number \| shares	1,068,193
Options Outstanding, Weighted Average Remaining Contractual Life (in years)	9 years 10 months 17 days
Options Outstanding, Weighted Average Exercise Price	$ 4.84
Options Exercisable, Number Exercisable \| shares	4,500
Options Exercisable, Weighted Average Exercise Price	$ 10.09
$10.35 - $11.72
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Range of Exercise Prices, Minimum	10.35
Range of Exercise Prices, Maximum	$ 11.72
Options Outstanding, Number \| shares	1,447,250
Options Outstanding, Weighted Average Remaining Contractual Life (in years)	9 years 7 months 17 days
Options Outstanding, Weighted Average Exercise Price	$ 10.58
Options Exercisable, Weighted Average Exercise Price	0.00
$11.73 - $13.04
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Range of Exercise Prices, Minimum	11.73
Range of Exercise Prices, Maximum	$ 13.04
Options Outstanding, Number \| shares	2,253,228
Options Outstanding, Weighted Average Remaining Contractual Life (in years)	8 years 2 months 1 day
Options Outstanding, Weighted Average Exercise Price	$ 12.85
Options Exercisable, Number Exercisable \| shares	1,031,129
Options Exercisable, Weighted Average Exercise Price	$ 12.85
$13.05 - $88.98
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Range of Exercise Prices, Minimum	13.05
Range of Exercise Prices, Maximum	$ 88.98
Options Outstanding, Number \| shares	2,037,271
Options Outstanding, Weighted Average Remaining Contractual Life (in years)	9 years 18 days
Options Outstanding, Weighted Average Exercise Price	$ 31.48
Options Exercisable, Number Exercisable \| shares	288,214
Options Exercisable, Weighted Average Exercise Price	$ 38.39

Stock-Based Compensation - Schedule of Fair Value of Each Option Estimated on Date of Grant Using Weighted Average Assumptions (Details) - Stock Options	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility	84.82%	115.05%
Risk-free interest rate	2.39%	0.93%
Expected life (in years)	6 years 3 days	5 years 10 months 28 days

Stock-Based Compensation - Summary of Activity related to RSA Stock-Based Payment Awards (Details) - Restricted Stock	6 Months Ended
	Jun. 30, 2022 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares, Unvested balance at beginning of period \| shares	611,608
Number of shares, Vested \| shares	(231,760)
Number of shares, Forfeited \| shares	(23,416)
Number of shares, Unvested balance at end of period \| shares	356,432
Weighted-average grant date fair value, Unvested balance at beginning of period \| $ / shares	$ 2.29
Weighted-average grant date fair value, Vested \| $ / shares	1.88
Weighted-average grant date fair value, Forfeited \| $ / shares	1.89
Weighted-average grant date fair value, Unvested balance at end of period \| $ / shares	$ 2.58

Stock-Based Compensation - Summary of Activity related to RSU Stock-Based Payment Awards (Details) - Restricted Stock Units (RSUs)	6 Months Ended
	Jun. 30, 2022 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares, Unvested balance at beginning of period \| shares	20,000
Number of shares, Granted \| shares	150,000
Number of shares, Unvested balance at end of period \| shares	170,000
Weighted-average grant date fair value, Unvested balance at beginning of period \| $ / shares	$ 18.32
Weighted-average grant date fair value, Granted \| $ / shares	4.86
Weighted-average grant date fair value, Unvested balance at end of period \| $ / shares	$ 6.44