PMV Pharmaceuticals (PMVP) 10-Q 14 May 21 2021 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2021	May 12, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Mar. 31, 2021
Entity File Number	001-39539
Entity Registrant Name	PMV PHARMACEUTICALS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	46-3218129
Entity Address, Address Line One	8 Clarke Drive
Entity Address, Address Line Two	Suite 3
Entity Address, City or Town	Cranbury
Entity Address, State or Province	NJ
Entity Address, Postal Zip Code	08512
City Area Code	609
Local Phone Number	642-6670
Title of 12(b) Security	Common stock, par value $0.00001
Trading Symbol	PMVP
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Bankruptcy Proceedings, Reporting Current	true
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		45,033,422
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Entity Central Index Key	0001699382
Amendment Flag	false

Condensed Balance Sheets (Unaud

Condensed Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 208,783	$ 361,422
Marketable securities, current	122,706
Prepaid expenses and other current assets	3,464	3,339
Total current assets	334,953	364,761
Property and equipment, net	697	569
Marketable securities, noncurrent	16,891
Right-of-use assets, operating leases	828
Other assets	1,024	201
Total assets	354,393	365,531
Current liabilities:
Accounts payable	1,252	1,607
Accrued expenses	3,878	4,803
Operating lease liability, current	666
Total current liabilities	5,796	6,410
Operating lease liability, noncurrent	302
Total liabilities	6,098	6,410
Stockholders’ equity:
Preferred stock, $0.00001 par value, 5,000,000 shares authorized at March 31, 2021 (unaudited) and December 31, 2020. No shares issued or outstanding at March 31, 2021 (unaudited) and December 31, 2020.
Common stock, $0.00001 par value, 1,000,000,000 shares authorized; 44,881,169 and 44,777,818 shares issued and outstanding at March 31, 2021 (unaudited) and December 31, 2020, respectively
Additional paid-in capital	469,790	469,001
Accumulated deficit	(121,482)	(109,880)
Accumulated other comprehensive loss	(13)
Total stockholders’ equity	348,295	359,121
Total liabilities and stockholders’ equity	$ 354,393	$ 365,531

Condensed Balance Sheets (Una_2

Condensed Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Mar. 31, 2021	Dec. 31, 2020
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.00001	$ 0.00001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.00001	$ 0.00001
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	44,881,169	44,777,818
Common stock, shares outstanding	44,881,169	44,777,818

Condensed Statements of Operati

Condensed Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating expenses:
Research and development	$ 7,500	$ 5,955
General and administrative	4,174	1,699
Total operating expenses	11,674	7,654
Loss from operations	(11,674)	(7,654)
Other income (expense):
Interest income, net	128	406
Other expense	(52)	(5)
Total other income	76	401
Loss before provision for income taxes	(11,598)	(7,253)
Provision for income taxes	4	2
Net loss	(11,602)	(7,255)
Unrealized losses on marketable securities, net of tax	(13)	(80)
Comprehensive loss	$ (11,615)	$ (7,335)
Net loss per share -- basic and diluted	$ (0.26)	$ (2.38)
Weighted-average common shares outstanding	44,785,226	3,046,200

Condensed Statements of Convert

Condensed Statements of Convertible Preferred Stock and Stockholders' (Deficit) Equity (Unaudited) - USD ($) $ in Thousands	Total	Convertible Preferred Stock	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
Balance at Dec. 31, 2019	$ (70,474)			$ 4,969	$ (3)	$ (75,440)
Balance, Shares at Dec. 31, 2019		22,866,246
Balance at Dec. 31, 2019		$ 168,933
Balance, Shares at Dec. 31, 2019			3,046,200
Stock-based compensation expense	296			296
Net loss	(7,255)					(7,255)
Unrealized loss on available for sale investments	(80)				(80)
Balance at Mar. 31, 2020	(77,513)			5,265	(83)	(82,695)
Balance, Shares at Mar. 31, 2020		22,866,246
Balance at Mar. 31, 2020		$ 168,933
Balance, Shares at Mar. 31, 2020			3,046,200
Balance at Dec. 31, 2020	359,121			469,001		(109,880)
Balance, Shares at Dec. 31, 2020			44,777,818
Exercise of stock options	$ 162			162
Exercise of stock options, Shares	103,351		103,351
Stock-based compensation expense	$ 627			627
Net loss	(11,602)					(11,602)
Unrealized loss on available for sale investments	(13)				(13)
Balance at Mar. 31, 2021	$ 348,295			$ 469,790	$ (13)	$ (121,482)
Balance, Shares at Mar. 31, 2021			44,881,169

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net loss	$ (11,602)	$ (7,255)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	627	296
Depreciation	79	94
Amortization of premiums on marketable securities	167	87
Other		5
Prepaid expenses and other assets	(948)	(24)
Accounts payable	(355)	(1,255)
Accrued expenses	(872)	(86)
Net cash used in operating activities	(12,904)	(8,138)
Cash flows from investing activities:
Purchase of property and equipment	(120)	(51)
Purchase of marketable securities	(139,777)	(14,828)
Maturities of marketable securities		8,495
Net cash used in investing activities	(139,897)	(6,384)
Cash flows from financing activities:
Proceeds from exercise of stock options	162
Net cash provided by financing activities	162
Net decrease in cash and cash equivalents	(152,639)	(14,522)
Cash and cash equivalents
Cash and cash equivalents - beginning of period	361,422	73,278
Cash and cash equivalents - end of period	208,783	58,756
Supplemental disclosures of cash flow information
Cash paid for income tax	$ 4	$ 2

Formation and Business of the C

Formation and Business of the Company	3 Months Ended
	Mar. 31, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Formation and Business of the Company	1. Formation and Business of the Company Organization and Liquidity PMV Pharmaceuticals, Inc. (the “Company”) was incorporated in the state of Delaware in March 2013. Since inception, the Company has devoted substantially all of its time and efforts to performing research and development activities and raising capital. The Company is a precision oncology company pioneering the discovery and development of small molecule, tumor-agnostic therapies targeting p53 mutations. The Company’s headquarters are located in Cranbury, New Jersey. The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry including, but not limited to, technical risks associated with the successful research, development and manufacturing of product candidates, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, compliance with government regulations and the ability to secure additional capital to fund operations. Current and future programs will require significant research and development efforts, including extensive preclinical and clinical testing and regulatory approval prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales. On September 25, 2020, the Company completed an initial public offering (the “IPO”) of 13,529,750 shares of common stock, at a public offering price of $18.00 per share including the exercise in full by the underwriters of their option to purchase up to 1,764,750 additional shares of commons stock, for aggregate gross proceeds of $243,536 and its shares started trading on The Nasdaq Global Select Market under the ticker symbol “PMVP.” The Company received $223,161 in net proceeds after deducting underwriting discounts and commissions and other offering expenses payable by the Company. In connection with the closing of the IPO, all of the Company’s outstanding shares of convertible preferred stock outstanding at the time of the IPO automatically converted into 28,188,110 shares of common stock. On September 18, 2020, the Company amended its certificate of incorporation to effect a 5.2651-for-1 reverse stock split of its issued and outstanding common and convertible preferred stock. The accompanying unaudited condensed financial statements and related notes give retroactive effect to the reverse stock split for all periods presented. The Company has incurred net losses and negative cash flows from operations since its inception. During the three months ended March 31, 2021, the Company incurred a net loss of $11,602 and used $12,904 of cash for operations. At March 31, 2021, the Company had an accumulated deficit of $121,482. Cash and cash equivalents at March 31, 2021 were $208,783. Short and long term marketable securities totaled $139,597 at March 31, 2021. Management expects to incur substantial additional operating losses for the next several years and will need to obtain additional debt or equity financings in order to complete development of its products, obtain regulatory approvals, launch and commercialize its products and continue research and development programs. The Company believes it has adequate cash and cash equivalents to operate for at least the next twelve months from the date of issuance of these unaudited condensed financial statements.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies The Company’s significant accounting policies are disclosed in the audited financial statements for the year ended December 31, 2020, included in the Company’s Annual Report on Form 10-K filed with the United States Securities and Exchange Commission (“SEC”) on March 3, 2021. Since the date of those financial statements, there have been no changes to its significant accounting policies except as noted below. Basis of Presentation The accompanying unaudited condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) for interim financial information and with the interim period reporting requirements of Form 10-Q and Article 10 of Regulation S-X. The condensed balance sheet as of March 31, 2021, the condensed statements of operations and comprehensive loss, and condensed statements of convertible preferred stock and stockholders’ (deficit) equity for the three months ended March 31, 2021 and 2020, and the condensed statements of cash flows for the three months ended March 31, 2021 and 2020 are unaudited, but, in the opinion of management, include all adjustments, consisting only of normal recurring adjustments, which we consider necessary for a fair presentation of the financial position, operating results and cash flows for the periods presented. The results for any interim period are not necessarily indicative of results for the year ending December 31, 2021 or for any other subsequent interim period. The condensed balance sheet at December 31, 2020 has been derived from our audited financial statements. Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and reported amounts of revenues and expenses during the reporting period. The Company bases its estimates and assumptions on historical experience when available and on various factors that it believes to be reasonable under the circumstances. Significant estimates and assumptions reflected in these financial statements include, but are not limited to, the fair values of common stock, convertible preferred stock and stock-based compensation. Actual results could differ materially from those estimates. Reverse Stock Split In September 2020, the Company’s board of directors and stockholders approved an amendment to the Company’s amended and restated certificate of incorporation to effect a 5.2651-for-1 reverse stock split of the Company’s common stock and convertible preferred stock, which was effected on September 18, 2020. The par value of the common stock and convertible preferred stock were not adjusted as a result of the reverse stock split. Accordingly, all common stock, convertible preferred stock, stock options, and related per share amounts in these unaudited condensed financial statements have been retroactively adjusted for all periods presented to give effect to the reverse stock split. Cash, Cash Equivalents and Marketable Securities Management considers all highly liquid investments with original maturities of three months or less to be cash equivalents. The Company’s marketable debt securities have been classified and accounted for as available-for-sale. The Company classifies its marketable debt securities as either short-term or long-term based on each instrument’s underlying contractual maturity date. Marketable debt securities with maturities of 12 months or less are classified as short-term and marketable debt securities with maturities greater than 12 months are classified as long-term. The Company’s marketable debt securities are carried at fair value, with unrealized gains and losses, net of taxes, reported as a component of accumulated other comprehensive loss in stockholders’ deficit. Premiums and discounts on marketable debt securities are amortized into earnings over the life of the security. For the three months ended March 31, 2021 and 2020, the Company recorded $167 and $87 of amortization, respectively. Comprehensive Loss The Company presents comprehensive loss in a single statement within its financial statements. Other comprehensive loss consists of unrealized gains and losses on marketable securities, net of tax. Leases At the inception of an arrangement, the Company determines whether the arrangement is or contains a lease based on the circumstances present. The Company accounts for a contract as a lease when it has the right to control the asset for a period of time while obtaining substantially all of the asset’s economic benefits. The Company determines the initial classification and measurement of its operating right-of-use (“ROU”) assets and operating lease liabilities at the lease commencement date, and thereafter if modified. The lease term includes any renewal options that the Company is reasonably assured to exercise. The Company’s policy is to not record leases with a lease term of 12 months or less on its balance sheets. The Company’s only existing lease is for office space. The ROU asset represents the right to use the leased asset for the lease term. The lease liability represents the present value of the lease payments under the lease. The present value of lease payments is determined by using the interest rate implicit in the lease, if that rate is readily determinable; otherwise, the Company uses its estimated secured incremental borrowing rate for that lease term. Lease expense for operating leases is recognized on a straight-line basis over the reasonably assured lease term based on the total lease payments and is included in operating expense in the statements of operations. Payments due under each lease agreement include fixed and variable payments. Variable payments relate to the Company’s share of the lessor’s operating costs associated with the underlying asset and are recognized when the event on which those payments are assessed occurs. Neither of the Company’s leases contain residual value guarantees. The interest rate implicit in lease agreements is typically not readily determinable, and as such, the Company utilizes the incremental borrowing rate to calculate lease liabilities, which is the rate incurred to borrow on a collateralized basis over a similar term an amount equal to the lease payments in a similar economic environment. Recently Issued and Adopted Accounting Pronouncements In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2016-02, Leases The right-of-use lease liability for operating leases is based on the net present value of future minimum lease payments. Additionally, the right-of-use asset for operating leases is based on the lease liability adjusted for the reclassification of certain balance sheet amounts such as the long term portion of straight line rent liability and deferred lease incentives. The Company adopted the standard effective January 1, 2021 using the modified retrospective transition method. Upon adoption, the Company applied the package of practical expedients that allows an entity to not reassess (i) whether any expired or existing contracts are or contain leases, (ii) lease classification for any expired or existing leases and (iii) initial direct costs for any expired or existing leases. The Company elected the practical expedient not to apply the recognition requirements to short-term leases, defined as a lease that at the commencement date has a lease term of 12 months or less that does not include a purchase option to purchase the underlying asset that the Company is reasonably certain to exercise. Furthermore, the Company has elected the practical expedient to not separate lease and non-lease components by class of underlying asset for its existing leases. As the Company enters into new leases, it will continue to evaluate this accounting policy for any new classes of underlying assets. Upon adoption, the Company recorded ROU assets of $970 and lease liabilities of $1,129. The standard did not have a material impact on the statement of operations or statement of cash flows. In December 2019, the FASB issued ASU 2019-12, Income Taxes – Simplifying the Accounting for Income Taxes. The new guidance simplifies the accounting for income taxes by removing several exceptions in the current standard and adding guidance to reduce complexity in certain areas, such as requiring that an entity reflect the effect of an enacted change in tax laws or rates in the annual effective tax rate computation in the interim period that includes the enactment date. The Company adopted this standard as of January 1, 2021. The adoption did not have a material impact on the Company’s financial statements. Concentration of Credit Risk and Other Risks and Uncertainties Financial instruments that potentially subject the Company to significant concentrations of credit risk consist of cash and cash equivalents and marketable securities. Cash and cash equivalents includes a checking account held at one financial institution. At times, such deposits may be in excess of insured limits. The Company has not experienced any losses on its deposits of cash and cash equivalents. The Company’s marketable debt securities are carried at fair value and include any unrealized gains and losses. Any investments with unrealized losses are considered to be temporarily impaired. The Company’s future results of operations involve a number of risks and uncertainties. Factors that could affect the Company’s future operating results and cause actual results to vary materially from expectations include, but are not limited to, rapid technological change, uncertainty of market acceptance of the product, competition from substitute products and larger companies, protection of proprietary technology, any future strategic relationships and dependence on key individuals. Products developed by the Company require clearances from the U.S. Food and Drug Administration or other international regulatory agencies prior to commercial sales. There can be no assurance the Company’s product candidates will receive the necessary clearances. If the Company is denied clearance, clearance is delayed or it is unable to maintain clearance, it could have a materially adverse impact on the Company. In January 2020, the World Health Organization declared the outbreak of a novel coronavirus (COVID-19) as a “Public Health Emergency of International Concern,” which continues to spread throughout the world. The outbreak has adversely impacted global commercial activity and contributed to significant volatility in financial markets. The COVID-19 outbreak and government responses are creating disruption in global supply chains and adversely impacting many industries. The outbreak could have a continued material adverse impact on economic and market conditions and trigger a period of global economic slowdown. The Company continues to monitor the impact of the COVID-19 outbreak closely. The full extent to which the COVID-19 outbreak will impact its operations or financial results remains uncertain.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Financial Instruments and Fair Value Measurements	3. Fair Value Measurements The Company’s financial assets consist of money market funds, U.S. government debt securities and corporate debt securities. The following tables show the Company’s cash equivalents and available-for-sale securities’ carrying amounts and fair values at March 31, 2021 and December 31, 2020: As of March 31, 2021 (unaudited) Carrying Amount Fair Value Quoted priced in active markets (level 1) Significant other observable inputs (level 2) Significant unobservable inputs (level 3) Financial assets Money market funds $ 41,268 $ 41,268 $ 41,268 $ — $ — Corporate securities 280,534 280,534 — 280,534 — Government securities 25,562 25,562 — 25,562 — Total financial assets $ 347,364 $ 347,364 $ 41,268 $ 306,096 $ — As of December 31, 2020 Carrying Amount Fair Value Quoted Priced in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial assets Money market funds 240,033 240,033 240,033 $ — $ — Corporate securities 120,008 120,008 — 120,008 — Total financial assets $ 360,041 $ 360,041 $ 240,033 $ 120,008 $ — Cash Equivalents — Cash equivalents of $207.8 million as of March 31, 2021 consisted of money market funds of $41.3 million and corporate debt securities of $166.5 million. Cash equivalents of $360.0 million as of December 31, 2020 consisted of money market funds of $240.0 million and corporate debt securities of $120.0 million. Money market funds are classified within level 1 of the fair value hierarchy because they are valued using quoted market prices in active markets, whereas corporate debt securities are classified within level 2 of the fair value hierarchy because they are valued using inputs other than quoted prices that are observable for the asset or liability either directly or indirectly. Marketable Securities — There were $122.7 million current marketable securities and $16.9 million noncurrent marketable securities as of March 31, 2021. There were no marketable securities as of December 31, 2020.

Property and Equipment, Net

Property and Equipment, Net	3 Months Ended
	Mar. 31, 2021
Property Plant And Equipment [Abstract]
Property and Equipment, Net	4. Property and Equipment, Net March 31, 2021 (unaudited) December 31, 2020 Machinery & equipment $ 2,061 $ 1,989 Computers 8 8 Furniture & fixtures 9 9 Leasehold improvements 161 73 Assets not placed in service 99 51 Total property and equipment 2,338 2,130 Less: Accumulated depreciation (1,641 ) (1,561 ) Property and equipment, net $ 697 $ 569 Depreciation expense for the three months ended March 31, 2021 and 2020 was $79 and $94, respectively.

Accrued Expenses

Accrued Expenses	3 Months Ended
	Mar. 31, 2021
Payables And Accruals [Abstract]
Accrued Expenses	5. Accrued Expenses Accrued expenses consist of the following: March 31, 2021 (unaudited) December 31, 2020 Accrued compensation $ 1,814 $ 3,109 Accrued legal and professional services 205 — Accrued research and development costs 1,819 1,595 Other accrued liabilities 40 99 Total $ 3,878 $ 4,803

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2021
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	6. Commitments and Contingencies Operating Leases In June 2015, the Company executed a noncancelable operating lease for approximately 13,000 square feet of laboratory, research and development, and office space in Cranbury, New Jersey for an initial base rent of $20.00 per square foot. This location operates as the Company’s headquarters. In June 2017, the Company obtained an additional noncancelable operating lease for about 6,000 square feet of laboratory space in the same corporate center at an initial rental rate at $22.00 per square foot. As a result of the additional space, both leases will expire July 2022, with an option to renew for an additional five-year term. Both leases include a common area maintenance expense for $3.00 per square foot with an increase of 3% on the first month of each calendar year during the lease term and a management fee of 3% of the base rent. In August 2018, the Company executed two noncancelable operating leases. One lease for approximately 6,000 square feet for vivarium, laboratory and general office space in South Brunswick, New Jersey. The initial annual base rent is $15.50 per square foot and a management fee of 3% of the base rent. The Company is obligated to pay, on a pro-rata basis, insurance premiums, real estate taxes and operating costs related to the premises. The lease expires in July 2022, with an option for additional five-year term. The second lease is for office space in Lexington, Massachusetts, that expires August 2023, with an option to renew for a one-time, three-year extension. The initial annual base rent is $28.50 per square foot and will increase $1.00 per square foot at the end of each rent year. The lease agreement in Lexington, Massachusetts allows for a tenant improvement allowance not to exceed $165 to be applied to the total cost of tenant improvements to the leased premises. Tenant improvement allowances due or received are recorded as deferred rent incentives on the Company’s condensed consolidated balance sheets, which are amortized to rent expense over the term of the lease. As of March 31, 2021, deferred rent incentives totaled $88. The components of lease cost for the three months ended March 31, 2021 are as follows: (in thousands) Three Months Ended March 31, 2021 Operating lease cost $ 157 Variable lease cost 95 Total lease cost $ 252 Amounts reported in the consolidated balance sheets for leases where the Company is the lessee as of March 31, 2021 were as follows, in thousands: Operating Leases: Three Months Ended March 31, 2021 Right-of-use assets, operating leases $ 828 Operating lease liabilities, current $ 666 Operating lease liabilities, non-current 302 Total operating lease liabilities $ 968 Weighted-average remaining lease term (years) 1.55 Weighted-average discount rate 5.75 % Other information related to leases for the three months ended March 31, 2021 is as follows, in thousands: Cash paid for amounts included in the measurement of lease liabilities $ 174 Leased assets obtained in exchange for new operating lease liabilities — Minimum lease payments under operation leases by fiscal year were as follows, in thousands: Fiscal year Year Ended December 31, 2020 2021 $ 525 2022 413 2023 71 2024 — 2025 — Thereafter — Total minimum lease payments $ 1,009 Less: Amounts representing imputed interest (41 ) Present value of lease liabilities $ 968 (1) Excluded from the table above are the lease payments associated with the lease of office and laboratory space in Princeton, New Jersey for the Company’s future headquarters. The Company has excluded its lease payments due to the commencement date not having occurred and a lease liability not yet having been recognized on its condensed balance sheet. Rent expense recorded during the three months ended March 31, 2021 and 2020 was $137 and $186, respectively. In January 2021, the Company signed a lease for 50,581 square feet of office and laboratory space at One Research Way in Princeton, New Jersey. Contingencies From time to time, the Company may have certain contingent liabilities that arise in the ordinary course of its business activities. The Company accrues a liability for such matters when future expenditures are probable and such expenditures can be reasonably estimated. Commitments At March 31, 2021, there were no purchase commitments with third-party suppliers.

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2021
Equity [Abstract]
Stockholders' Equity	7. Stockholders’ Equity The Company is authorized to issue up to 1,000,000,000 shares of common stock with a par value of $0.00001 per share and 5,000,000 shares of preferred stock with a par value of $0.00001 per share. At March 31, 2021 and December 31, 2020, there were 44,881,169 and 44,777,818 shares of common stock issued and outstanding, respectively, and no shares of preferred stock issued and outstanding. Common stockholders are entitled to receive dividends if and when declared by the board of directors subject to the rights of any preferred stockholders. As of March 31, 2021, no dividends on common stock had been declared by the Company.

Stock Plan

Stock Plan	3 Months Ended
	Mar. 31, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Plan	8. Stock Plan 2020 Equity Incentive Plan The 2020 Equity Incentive Plan (the “2020 Plan”) was approved by the board of directors on September 24, 2020. The 2020 Plan provides for the grant of incentive stock options, non-qualified stock options, stock appreciation rights, restricted stock units, restricted stock awards, unrestricted stock awards, cash-based awards and dividend equivalent rights to the Company’s officers, employees, directors and consultants. The number of shares initially reserved for issuance under the 2020 Plan is 4,406,374, which shall be, upon approval by the board of directors, cumulatively increased on January 1, 2021 and each January 1 thereafter by 5% of the number of shares of the Company’s common stock outstanding on the immediately preceding December 31. As of March 31, 2021, there were 4,367,896 shares available for issuance under the 2020 Plan. 2020 Employee Stock Purchase Plan The 2020 Employee Stock Purchase Plan (the “2020 ESPP”) was approved by the board of directors on September 24, 2020. A total of 400,572 shares of common stock were initially reserved for issuance under this plan, which shall be increased, upon approval by the board of directors, on January 1, 2021 to the lesser of (i) 801,504 shares of common stock, (ii) 1% of the outstanding shares of common stock on the last day of the immediately preceding fiscal year, or (iii) an amount determined by the Administrator no later than the last day of the immediately preceding fiscal year. As of March 31, 2021, no shares are issued or outstanding under the 2020 ESPP. 2013 Equity Incentive Plan In 2013, the Company adopted the 2013 Stock Plan (the “2013 Plan”). On September 24, 2020, this plan was replaced by the 2020 Plan, and future issuances of incentive instruments will be governed by that plan. Subject to the provisions of the 2020 Plan, the Company had the option to either forfeit or repurchase remaining shares under the 2013 Equity Incentive Plan on or after the registration date. The Company chose to forfeit the remaining shares. Stock-Based Compensation This table summarizes option activity for the three-month period ended March 31, 2021: Options Outstanding Weighted- Weighted Average Aggregate Shares Average Remaining Intrinsic Available Number of Exercise Contractual Life Value for Grant Options Price (in years) (in 000s) Balances, December 31, 2020 4,609,725 4,090,970 $ 3.14 7.13 $ 238,792 Options retired under 2013 Equity Plan (237,542 ) — Options granted (23,500 ) 23,500 $ 34.30 Options forfeited / cancelled 19,213 (19,213 ) $ 3.86 0.00 Options exercised — (103,351 ) $ 1.57 Balances, March 31, 2021 (unaudited) 4,367,896 3,991,906 $ 3.36 6.77 $ 117,965 At March 31, 2021 Vested and expected to vest 3,991,906 $ 3.34 6.77 $ 117,965 Exercisable 2,644,954 $ 2.20 5.81 $ 81,134 At March 31, 2021, the total compensation cost related to nonvested awards not yet recognized is $4,683. The weighted-average period over which the nonvested awards is expected to be recognized is 3.0 years. The Company estimated the fair value of the options using the Black-Scholes options valuation model. The fair value of the options is being amortized on a straight-line basis over the requisite service period of the awards. The fair value was estimated using the following assumptions: Three Months Ended Year Ended March 31, December 31, 2021 2020 Risk-free interest rate 0.65% 0.31% - 1.51% Expected life (in years) 6.25 4.92 - 6.40 Dividend yield 0% 0% Expected volatility 79.90% 70.70% - 77.60% Expected Term: The Company uses the simplified method to calculate expected term described in the SEC’s Staff Accounting Bulletin No. 107, which takes into account vesting term and expiration date of the options. Volatility: Volatility is based on an average of the historical volatilities of comparable publicly traded companies for the expected term. Risk Free Interest Rate: The risk-free rate is based on the U.S. Treasury yields in effect at the time of grant for periods corresponding with the expected term of the option. Dividend Yield: The Company has never declared or paid any cash dividends and does not plan to pay cash dividends in the foreseeable future, and therefore, used an expected dividend yield of zero in the valuation model. Stock-based compensation expense recorded under ASC 718 related to stock options granted was allocated to research and development and general and administrative expense as follows: For the Three Months Ended March 31, March 31, 2021 2020 Research and development $ 251 $ 142 General and administrative 376 154 Total stock-based compensation $ 627 $ 296

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	9. Income Taxes During the three months ended March 31, 2021 and 2020, the Company recorded a full valuation allowance on federal and state deferred tax assets since management does not forecast the Company to be in a taxable position in the near future.

Net Loss per Share

Net Loss per Share	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Net Loss per Share	10. Net Loss per Share The Company’s convertible preferred stock does not participate in losses. For the Three Months Ended March 31, 2021 (unaudited) March 31, 2020 (unaudited) Net loss $ (11,602 ) $ (7,255 ) Weighted-average number of shares - basic and diluted 44,785,226 3,046,200 Net loss per share - basic and diluted (0.26 ) (2.38 )

Related Parties

Related Parties	3 Months Ended
	Mar. 31, 2021
Related Party Transactions [Abstract]
Related Parties	11. Related Parties The Company has consulting agreements with two members of the board of directors. Consulting fees paid in each of the three months ended March 31, 2021 and 2020 were $28. There were no amounts owed under the consulting agreement at March 31, 2021 or December 31, 2020. During the fiscal year ended December 31, 2020, an investor provided $65 of financial consulting services to the Company. The Company has paid the entirety of the fees as of December 31, 2020. No amounts were paid or owed to the investors in the three months ended March 31, 2021.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) for interim financial information and with the interim period reporting requirements of Form 10-Q and Article 10 of Regulation S-X. The condensed balance sheet as of March 31, 2021, the condensed statements of operations and comprehensive loss, and condensed statements of convertible preferred stock and stockholders’ (deficit) equity for the three months ended March 31, 2021 and 2020, and the condensed statements of cash flows for the three months ended March 31, 2021 and 2020 are unaudited, but, in the opinion of management, include all adjustments, consisting only of normal recurring adjustments, which we consider necessary for a fair presentation of the financial position, operating results and cash flows for the periods presented. The results for any interim period are not necessarily indicative of results for the year ending December 31, 2021 or for any other subsequent interim period. The condensed balance sheet at December 31, 2020 has been derived from our audited financial statements.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and reported amounts of revenues and expenses during the reporting period. The Company bases its estimates and assumptions on historical experience when available and on various factors that it believes to be reasonable under the circumstances. Significant estimates and assumptions reflected in these financial statements include, but are not limited to, the fair values of common stock, convertible preferred stock and stock-based compensation. Actual results could differ materially from those estimates.
Reverse Stock Split	Reverse Stock Split In September 2020, the Company’s board of directors and stockholders approved an amendment to the Company’s amended and restated certificate of incorporation to effect a 5.2651-for-1 reverse stock split of the Company’s common stock and convertible preferred stock, which was effected on September 18, 2020. The par value of the common stock and convertible preferred stock were not adjusted as a result of the reverse stock split. Accordingly, all common stock, convertible preferred stock, stock options, and related per share amounts in these unaudited condensed financial statements have been retroactively adjusted for all periods presented to give effect to the reverse stock split.
Cash, Cash Equivalents and Marketable Securities	Cash, Cash Equivalents and Marketable Securities Management considers all highly liquid investments with original maturities of three months or less to be cash equivalents. The Company’s marketable debt securities have been classified and accounted for as available-for-sale. The Company classifies its marketable debt securities as either short-term or long-term based on each instrument’s underlying contractual maturity date. Marketable debt securities with maturities of 12 months or less are classified as short-term and marketable debt securities with maturities greater than 12 months are classified as long-term. The Company’s marketable debt securities are carried at fair value, with unrealized gains and losses, net of taxes, reported as a component of accumulated other comprehensive loss in stockholders’ deficit. Premiums and discounts on marketable debt securities are amortized into earnings over the life of the security. For the three months ended March 31, 2021 and 2020, the Company recorded $167 and $87 of amortization, respectively.
Comprehensive Loss	Comprehensive Loss The Company presents comprehensive loss in a single statement within its financial statements. Other comprehensive loss consists of unrealized gains and losses on marketable securities, net of tax.
Leases	Leases At the inception of an arrangement, the Company determines whether the arrangement is or contains a lease based on the circumstances present. The Company accounts for a contract as a lease when it has the right to control the asset for a period of time while obtaining substantially all of the asset’s economic benefits. The Company determines the initial classification and measurement of its operating right-of-use (“ROU”) assets and operating lease liabilities at the lease commencement date, and thereafter if modified. The lease term includes any renewal options that the Company is reasonably assured to exercise. The Company’s policy is to not record leases with a lease term of 12 months or less on its balance sheets. The Company’s only existing lease is for office space. The ROU asset represents the right to use the leased asset for the lease term. The lease liability represents the present value of the lease payments under the lease. The present value of lease payments is determined by using the interest rate implicit in the lease, if that rate is readily determinable; otherwise, the Company uses its estimated secured incremental borrowing rate for that lease term. Lease expense for operating leases is recognized on a straight-line basis over the reasonably assured lease term based on the total lease payments and is included in operating expense in the statements of operations. Payments due under each lease agreement include fixed and variable payments. Variable payments relate to the Company’s share of the lessor’s operating costs associated with the underlying asset and are recognized when the event on which those payments are assessed occurs. Neither of the Company’s leases contain residual value guarantees. The interest rate implicit in lease agreements is typically not readily determinable, and as such, the Company utilizes the incremental borrowing rate to calculate lease liabilities, which is the rate incurred to borrow on a collateralized basis over a similar term an amount equal to the lease payments in a similar economic environment.
Recently Issued and Adopted Accounting Pronouncements	Recently Issued and Adopted Accounting Pronouncements In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2016-02, Leases The right-of-use lease liability for operating leases is based on the net present value of future minimum lease payments. Additionally, the right-of-use asset for operating leases is based on the lease liability adjusted for the reclassification of certain balance sheet amounts such as the long term portion of straight line rent liability and deferred lease incentives. The Company adopted the standard effective January 1, 2021 using the modified retrospective transition method. Upon adoption, the Company applied the package of practical expedients that allows an entity to not reassess (i) whether any expired or existing contracts are or contain leases, (ii) lease classification for any expired or existing leases and (iii) initial direct costs for any expired or existing leases. The Company elected the practical expedient not to apply the recognition requirements to short-term leases, defined as a lease that at the commencement date has a lease term of 12 months or less that does not include a purchase option to purchase the underlying asset that the Company is reasonably certain to exercise. Furthermore, the Company has elected the practical expedient to not separate lease and non-lease components by class of underlying asset for its existing leases. As the Company enters into new leases, it will continue to evaluate this accounting policy for any new classes of underlying assets. Upon adoption, the Company recorded ROU assets of $970 and lease liabilities of $1,129. The standard did not have a material impact on the statement of operations or statement of cash flows. In December 2019, the FASB issued ASU 2019-12, Income Taxes – Simplifying the Accounting for Income Taxes. The new guidance simplifies the accounting for income taxes by removing several exceptions in the current standard and adding guidance to reduce complexity in certain areas, such as requiring that an entity reflect the effect of an enacted change in tax laws or rates in the annual effective tax rate computation in the interim period that includes the enactment date. The Company adopted this standard as of January 1, 2021. The adoption did not have a material impact on the Company’s financial statements.
Concentration of Credit Risk and Other Risks and Uncertainties	Concentration of Credit Risk and Other Risks and Uncertainties Financial instruments that potentially subject the Company to significant concentrations of credit risk consist of cash and cash equivalents and marketable securities. Cash and cash equivalents includes a checking account held at one financial institution. At times, such deposits may be in excess of insured limits. The Company has not experienced any losses on its deposits of cash and cash equivalents. The Company’s marketable debt securities are carried at fair value and include any unrealized gains and losses. Any investments with unrealized losses are considered to be temporarily impaired. The Company’s future results of operations involve a number of risks and uncertainties. Factors that could affect the Company’s future operating results and cause actual results to vary materially from expectations include, but are not limited to, rapid technological change, uncertainty of market acceptance of the product, competition from substitute products and larger companies, protection of proprietary technology, any future strategic relationships and dependence on key individuals. Products developed by the Company require clearances from the U.S. Food and Drug Administration or other international regulatory agencies prior to commercial sales. There can be no assurance the Company’s product candidates will receive the necessary clearances. If the Company is denied clearance, clearance is delayed or it is unable to maintain clearance, it could have a materially adverse impact on the Company. In January 2020, the World Health Organization declared the outbreak of a novel coronavirus (COVID-19) as a “Public Health Emergency of International Concern,” which continues to spread throughout the world. The outbreak has adversely impacted global commercial activity and contributed to significant volatility in financial markets. The COVID-19 outbreak and government responses are creating disruption in global supply chains and adversely impacting many industries. The outbreak could have a continued material adverse impact on economic and market conditions and trigger a period of global economic slowdown. The Company continues to monitor the impact of the COVID-19 outbreak closely. The full extent to which the COVID-19 outbreak will impact its operations or financial results remains uncertain.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Summary of Cash Equivalents and Available-for-sale Securities Carrying Amounts and Fair Values	The Company’s financial assets consist of money market funds, U.S. government debt securities and corporate debt securities. The following tables show the Company’s cash equivalents and available-for-sale securities’ carrying amounts and fair values at March 31, 2021 and December 31, 2020: As of March 31, 2021 (unaudited) Carrying Amount Fair Value Quoted priced in active markets (level 1) Significant other observable inputs (level 2) Significant unobservable inputs (level 3) Financial assets Money market funds $ 41,268 $ 41,268 $ 41,268 $ — $ — Corporate securities 280,534 280,534 — 280,534 — Government securities 25,562 25,562 — 25,562 — Total financial assets $ 347,364 $ 347,364 $ 41,268 $ 306,096 $ — As of December 31, 2020 Carrying Amount Fair Value Quoted Priced in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial assets Money market funds 240,033 240,033 240,033 $ — $ — Corporate securities 120,008 120,008 — 120,008 — Total financial assets $ 360,041 $ 360,041 $ 240,033 $ 120,008 $ —

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	3 Months Ended
	Mar. 31, 2021
Property Plant And Equipment [Abstract]
Summary of Property and Equipment, Net	March 31, 2021 (unaudited) December 31, 2020 Machinery & equipment $ 2,061 $ 1,989 Computers 8 8 Furniture & fixtures 9 9 Leasehold improvements 161 73 Assets not placed in service 99 51 Total property and equipment 2,338 2,130 Less: Accumulated depreciation (1,641 ) (1,561 ) Property and equipment, net $ 697 $ 569

Accrued Expenses (Tables)

Accrued Expenses (Tables)	3 Months Ended
	Mar. 31, 2021
Payables And Accruals [Abstract]
Summary of Accrued Expenses	Accrued expenses consist of the following: March 31, 2021 (unaudited) December 31, 2020 Accrued compensation $ 1,814 $ 3,109 Accrued legal and professional services 205 — Accrued research and development costs 1,819 1,595 Other accrued liabilities 40 99 Total $ 3,878 $ 4,803

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2021
Commitments And Contingencies Disclosure [Abstract]
Summary of Components of Lease Cost	The components of lease cost for the three months ended March 31, 2021 are as follows: (in thousands) Three Months Ended March 31, 2021 Operating lease cost $ 157 Variable lease cost 95 Total lease cost $ 252
Schedule of Amounts Reported in Consolidated Balance Sheets for Leases	Amounts reported in the consolidated balance sheets for leases where the Company is the lessee as of March 31, 2021 were as follows, in thousands: Operating Leases: Three Months Ended March 31, 2021 Right-of-use assets, operating leases $ 828 Operating lease liabilities, current $ 666 Operating lease liabilities, non-current 302 Total operating lease liabilities $ 968 Weighted-average remaining lease term (years) 1.55 Weighted-average discount rate 5.75 %
Summary of Other Information Related to Leases	Other information related to leases for the three months ended March 31, 2021 is as follows, in thousands: Cash paid for amounts included in the measurement of lease liabilities $ 174 Leased assets obtained in exchange for new operating lease liabilities —
Schedule of Minimum Lease Payments under Operation Leases	Minimum lease payments under operation leases by fiscal year were as follows, in thousands: Fiscal year Year Ended December 31, 2020 2021 $ 525 2022 413 2023 71 2024 — 2025 — Thereafter — Total minimum lease payments $ 1,009 Less: Amounts representing imputed interest (41 ) Present value of lease liabilities $ 968 (1) Excluded from the table above are the lease payments associated with the lease of office and laboratory space in Princeton, New Jersey for the Company’s future headquarters. The Company has excluded its lease payments due to the commencement date not having occurred and a lease liability not yet having been recognized on its condensed balance sheet.

Stock Plan (Tables)

Stock Plan (Tables)	3 Months Ended
	Mar. 31, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Schedule of Stock Options Activity	This table summarizes option activity for the three-month period ended March 31, 2021: Options Outstanding Weighted- Weighted Average Aggregate Shares Average Remaining Intrinsic Available Number of Exercise Contractual Life Value for Grant Options Price (in years) (in 000s) Balances, December 31, 2020 4,609,725 4,090,970 $ 3.14 7.13 $ 238,792 Options retired under 2013 Equity Plan (237,542 ) — Options granted (23,500 ) 23,500 $ 34.30 Options forfeited / cancelled 19,213 (19,213 ) $ 3.86 0.00 Options exercised — (103,351 ) $ 1.57 Balances, March 31, 2021 (unaudited) 4,367,896 3,991,906 $ 3.36 6.77 $ 117,965 At March 31, 2021 Vested and expected to vest 3,991,906 $ 3.34 6.77 $ 117,965 Exercisable 2,644,954 $ 2.20 5.81 $ 81,134
Schedule of Estimated Fair Value of Stock Options	The Company estimated the fair value of the options using the Black-Scholes options valuation model. The fair value of the options is being amortized on a straight-line basis over the requisite service period of the awards. The fair value was estimated using the following assumptions: Three Months Ended Year Ended March 31, December 31, 2021 2020 Risk-free interest rate 0.65% 0.31% - 1.51% Expected life (in years) 6.25 4.92 - 6.40 Dividend yield 0% 0% Expected volatility 79.90% 70.70% - 77.60%
Stock-based Compensation Expense Related to Options Granted Recorded and Allocated	Stock-based compensation expense recorded under ASC 718 related to stock options granted was allocated to research and development and general and administrative expense as follows: For the Three Months Ended March 31, March 31, 2021 2020 Research and development $ 251 $ 142 General and administrative 376 154 Total stock-based compensation $ 627 $ 296

Net Loss per Share (Tables)

Net Loss per Share (Tables)	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Schedule of Computation of Net Loss per Share	For the Three Months Ended March 31, 2021 (unaudited) March 31, 2020 (unaudited) Net loss $ (11,602 ) $ (7,255 ) Weighted-average number of shares - basic and diluted 44,785,226 3,046,200 Net loss per share - basic and diluted (0.26 ) (2.38 )

Formation and Business of the_2

Formation and Business of the Company - Additional Information (Details)	Sep. 25, 2020USD ($)$ / sharesshares	Sep. 18, 2020	Mar. 31, 2021USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2020USD ($)
Organization Consolidation And Presentation [Line Items]
Proceeds from issuance of common stock, gross	$ 243,536
Proceeds from issuance of common stock, net	$ 223,161
Reverse stock split description			5.2651-for-1 reverse stock split of the Company’s common stock and convertible preferred stock
Reverse stock split conversion ratio		5.2651
Net loss			$ (11,602,000)	$ (7,255,000)
Cash used in operating activities			(12,904,000)	$ (8,138,000)
Accumulated deficit			(121,482,000)		$ (109,880,000)
Cash and cash equivalents			208,783,000		361,422,000
Short and long term marketable securities			$ 139,597,000		$ 0
Convertible Preferred Stock | Common Stock
Organization Consolidation And Presentation [Line Items]
Reverse stock split description			5.2651-for-1 reverse stock split of its issued and outstanding common and convertible preferred stock
IPO | Common Stock
Organization Consolidation And Presentation [Line Items]
Number of shares sold | shares	13,529,750
Public offering price per share | $ / shares	$ 18
IPO | Convertible Preferred Stock | Common Stock
Organization Consolidation And Presentation [Line Items]
Conversion of convertible preferred stock to common stock, Shares | shares	28,188,110
Underwriters | Common Stock
Organization Consolidation And Presentation [Line Items]
Option to purchase common stock | shares	1,764,750

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Details) $ in Thousands	Sep. 18, 2020	Mar. 31, 2021USD ($)	Mar. 31, 2020USD ($)	Jan. 01, 2021USD ($)
Summary Of Significant Accounting Policie [Line Items]
Reverse stock split description		5.2651-for-1 reverse stock split of the Company’s common stock and convertible preferred stock
Reverse stock split conversion ratio	5.2651
Amortization of available-for-sale debt securities		$ 167	$ 87
ROU assets		828
Lease liabilities		$ 968
ASU 2016-02
Summary Of Significant Accounting Policie [Line Items]
Adoption of accounting standards update [true false]		true
Accounting standards update, adoption date		Jan. 1, 2021
ROU assets				$ 970
Lease liabilities				$ 1,129
ASU 2019-12
Summary Of Significant Accounting Policie [Line Items]
Adoption of accounting standards update [true false]		true
Accounting standards update, adoption date		Jan. 1, 2021
Accounting standards update, immaterial effect [true false]		true

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Cash Equivalents and Available-for-sale Securities Carrying Amounts and Fair Values (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Quoted Priced in Active Markets (Level 1)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	$ 41,268	$ 240,033
Significant Other Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	306,096	120,008
Corporate Securities | Significant Other Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	280,534	120,008
Government Securities | Significant Other Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	25,562
Money Market Funds | Quoted Priced in Active Markets (Level 1)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	41,268	240,033
Carrying Amount
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	347,364	360,041
Carrying Amount | Corporate Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	280,534	120,008
Carrying Amount | Government Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	25,562
Carrying Amount | Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	41,268	240,033
Fair Value
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	347,364	360,041
Fair Value | Corporate Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	280,534	120,008
Fair Value | Government Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	25,562
Fair Value | Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	$ 41,268	$ 240,033

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	$ 207,800,000	$ 360,000,000
Marketable securities noncurrent	16,891,000
Marketable securities current	122,706,000
Marketable securities	139,597,000	0
Corporate Debt Securities | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	166,500,000	120,000,000
Money Market Funds | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	$ 41,300,000	$ 240,000,000

Property and Equipment, Net - S

Property and Equipment, Net - Summary of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Total property and equipment	$ 2,338	$ 2,130
Less: Accumulated depreciation	(1,641)	(1,561)
Property and equipment, net	697	569
Machinery & Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	2,061	1,989
Computers
Property Plant And Equipment [Line Items]
Total property and equipment	8	8
Furniture & Fixtures
Property Plant And Equipment [Line Items]
Total property and equipment	9	9
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total property and equipment	161	73
Assets Not Placed in Service
Property Plant And Equipment [Line Items]
Total property and equipment	$ 99	$ 51

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Property Plant And Equipment [Abstract]
Depreciation	$ 79	$ 94

Accrued Expenses - Summary of A

Accrued Expenses - Summary of Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Payables And Accruals [Abstract]
Accrued compensation	$ 1,814	$ 3,109
Accrued legal and professional services	205
Accrued research and development costs	1,819	1,595
Other accrued liabilities	40	99
Total	$ 3,878	$ 4,803

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details)	1 Months Ended		3 Months Ended
	Jan. 31, 2021USD ($)ft²	Aug. 31, 2018ft²Lease$ / ft²	Mar. 31, 2021USD ($)$ / ft²	Mar. 31, 2020USD ($)	Jun. 30, 2017ft²$ / ft²	Jun. 30, 2015ft²$ / ft²
Commitments And Contingencies Disclosure [Line Items]
Number of noncancelable operating leases | Lease		2
Deferred rent incentives			$ 88,000
Rent expense			137,000	$ 186,000
Cash paid for amounts included in the measurement of lease liabilities			174,000
Purchase commitments			$ 0
Cranbury, New Jersey
Commitments And Contingencies Disclosure [Line Items]
Area of operating lease property | ft²					6,000	13,000
Initial base rent per square foot | $ / ft²					22	20
Operating lease expiration period			2022-07
Operating lease, renewal term			5 years
Operating lease maintenance expense per square foot | $ / ft²			3
Operating lease, description			Both leases include a common area maintenance expense for $3.00 per square foot with an increase of 3% on the first month of each calendar year during the lease term and a management fee of 3% of the base rent.
Management fee of base rent percentage			3.00%
South Brunswick, New Jersey.
Commitments And Contingencies Disclosure [Line Items]
Area of operating lease property | ft²		6,000
Initial base rent per square foot | $ / ft²		15.50
Operating lease expiration period		2022-07
Operating lease, renewal term		5 years
Management fee of base rent percentage		3.00%
Lexington, Massachusetts
Commitments And Contingencies Disclosure [Line Items]
Initial base rent per square foot | $ / ft²		28.50
Operating lease expiration period		2023-08
Operating lease, renewal term		3 years
Initial base rent increased per square foot | $ / ft²		1
Maximum amount tenant improvement allowance			$ 165,000
Princeton, New Jersey
Commitments And Contingencies Disclosure [Line Items]
Operating lease, description			That lease term extends through 2032, has a five-year extension option, and is intended to replace our two existing facilities.
Lease area of square feet | ft²	50,581
Operating Leases, extended year	2032
Operating leases, extension period	5 years
Cash paid for amounts included in the measurement of lease liabilities	$ 19,600,000
Operating leases extended month and year	2032-05
Tenant improvement allowance	$ 4,100,000

Commitments and Contingencies_2

Commitments and Contingencies - Summary of Components of Lease Cost (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)
Leases [Abstract]
Operating lease cost	$ 157
Variable lease cost	95
Total lease cost	$ 252

Commitments and Contingencies_3

Commitments and Contingencies - Schedule of Amounts Reported in Consolidated Balance Sheets for Leases (Details) $ in Thousands	Mar. 31, 2021USD ($)
Operating Leases:
Right-of-use assets, operating leases	$ 828
Operating lease liability, current	666
Operating lease liability, noncurrent	302
Total operating lease liabilities	$ 968
Weighted-average remaining lease term (years)	1 year 6 months 18 days
Weighted-average discount rate	5.75%

Commitments and Contingencies_4

Commitments and Contingencies - Summary of Other Information Related to Leases (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)
Leases [Abstract]
Cash paid for amounts included in the measurement of lease liabilities	$ 174

Commitments and Contingencies_5

Commitments and Contingencies - Schedule of Minimum Lease Payments under Operation Leases (Details) $ in Thousands	Mar. 31, 2021USD ($)
Commitments And Contingencies Disclosure [Abstract]
2021	$ 525
2022	413
2023	71
Total minimum lease payments	1,009
Less: Amounts representing imputed interest	(41)
Present value of lease liabilities	$ 968

Stockholder's Equity - Addition

Stockholder's Equity - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Equity [Abstract]
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, par value	$ 0.00001	$ 0.00001
Common stock, shares issued	44,881,169	44,777,818
Common stock, shares outstanding	44,881,169	44,777,818
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, par value	$ 0.00001	$ 0.00001
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Dividends, common stock declared	$ 0

Stock Plan - Additional Informa

Stock Plan - Additional Information (Details) - USD ($) $ in Thousands	Sep. 24, 2020	Mar. 31, 2021	Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total compensation cost related to nonvested awards not yet recognized		$ 4,683
Weighted-average period over nonvested awards expected to be recognized		3 years
Dividend yield		0.00%	0.00%
2020 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares reserved for issuance	4,406,374	4,367,896
Percentage of number of shares of common stock outstanding increase	5.00%
Shares issued	4,367,896
2020 ESPP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares reserved for issuance	400,572
Percentage of number of shares of common stock outstanding increase	1.00%
Shares issued		0
Number of additional shares reserved for issuance, maximum	801,504
Shares outstanding		0

Stock Plan - Schedule of Stock

Stock Plan - Schedule of Stock Options Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Shares Available For Grant
Shares Available for Grant, Balance	4,609,725
Shares Available for Grant, Options granted	(23,500)
Shares Available for Grant, Options forfeited / cancelled	19,213
Shares Available for Grant, Balance	4,367,896	4,609,725
Number of Options
Options	4,090,970
Options granted, Number of Options	23,500
Options forfeited / cancelled, Number of Options	(19,213)
Options exercised, Number of Options	(103,351)
Options Outstanding, Number of Options	3,991,906	4,090,970
Vested and expected to vest, Number of Options	3,991,906
Exercisable, Number of Options	2,644,954
Weighted Average Exercise Price
Options Outstanding, Weighted Average Exercise Price	$ 3.14
Options granted, Weighted Average Exercise Price	34.30
Options forfeited / cancelled, Weighted Average Exercise Price	3.86
Options exercised, Weighted Average Exercise Price	1.57
Options Outstanding, Weighted Average Exercise Price	3.36	$ 3.14
Vested and expected to vest, Weighted Average Exercise Price	3.34
Exercisable, Weighted Average Exercise Price	$ 2.20
Weighted-Average Remaining Contractual Life
Options Outstanding, Weighted-Average Remaining Contractual Life	6 years 9 months 7 days	7 years 1 month 17 days
Options Forfeited/Cancelled, Weighted-Average Remaining Contractual Life	0 years
Vested and expected to vest, Weighted-Average Remaining Contractual Life	6 years 9 months 7 days
Exercisable, Weighted-Average Remaining Contractual Life	5 years 9 months 21 days
Aggregate Intrinsic Value
Options Outstanding, Aggregate Intrinsic Value	$ 117,965	$ 238,792
Vested and expected to vest, Aggregate Intrinsic Value	117,965
Exercisable, Aggregate Intrinsic Value	$ 81,134
2013 Stock Plan
Shares Available For Grant
Shares Available for Grant, Options retired	(237,542)

Stock Plan - Schedule of Estima

Stock Plan - Schedule of Estimated Fair Value of Stock Options (Details)	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate	0.65%
Risk-free interest rate, minimum		0.31%
Risk-free interest rate, maximum		1.51%
Expected life (in years)	6 years 3 months
Dividend yield	0.00%	0.00%
Expected volatility	79.90%
Expected volatility, minimum		70.70%
Expected volatility, maximum		77.60%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected life (in years)		4 years 11 months 1 day
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected life (in years)		6 years 4 months 24 days

Stock Plan - Stock-based Compen

Stock Plan - Stock-based Compensation Expense Related to Options Granted Recorded and Allocated (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	$ 627	$ 296
Research and Development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	251	142
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	$ 376	$ 154

Net Loss per Share - Schedule o

Net Loss per Share - Schedule of Computation of Net Loss per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Earnings Per Share [Abstract]
Net loss	$ (11,602)	$ (7,255)
Weighted-average number of shares - basic and diluted	44,785,226	3,046,200
Net loss per share -- basic and diluted	$ (0.26)	$ (2.38)

Related Parties - Additional In

Related Parties - Additional Information (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2021USD ($)Member	Mar. 31, 2020USD ($)	Dec. 31, 2020USD ($)
Board of Directors
Related Party Transaction [Line Items]
Number of consulting agreement members | Member	2
Consulting fees	$ 28,000	$ 28,000
Amount owed to related party	0		$ 0
Investor
Related Party Transaction [Line Items]
Consulting fees			$ 65,000
Amount owed to related party	0
Amount paid to related party	$ 0