Enliven Therapeutics (ELVN) 10-K 5 Mar 21 2020 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2020	Mar. 01, 2021	Jun. 30, 2020
Cover [Abstract]
Entity Registrant Name	IMARA INC.
Document Type	10-K
Trading Symbol	IMRA
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		17,575,248
Entity Public Float			$ 190,476,799
Amendment Flag	false
Entity Central Index Key	0001672619
Entity Filer Category	Non-accelerated Filer
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Title of 12(b) Security	Common stock, par value $0.001 per share
Security Exchange Name	NASDAQ
Entity File Number	001-39247
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	81-1523849
Entity Address, Address Line One	116 Huntington Avenue
Entity Address, Address Line Two	6th Floor
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02116
City Area Code	617
Local Phone Number	206-2020
Document Annual Report	true
Document Transition Report	false
ICFR Auditor Attestation Flag	false
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 47,698	$ 4,936
Short-term investments	40,524	23,971
Prepaid expenses and other current assets	2,183	1,717
Total current assets	90,405	30,624
Property and equipment, net	349	442
Other assets	88	2,232
Total assets	90,842	33,298
Current liabilities:
Accounts payable	1,971	1,658
Accrued expenses and other current liabilities	4,276	2,540
Total current liabilities	6,247	4,198
Deferred rent	160	184
Total liabilities	6,407	4,382
Commitments and contingencies (Note 8)
Convertible preferred stock		77,764
Stockholders' equity (deficit):
Preferred stock, $0.001 par value per share; 10,000,000 shares authorized; no shares issued or outstanding as of December 31, 2020; no shares authorized, issued or outstanding as of December 31, 2019
Common stock, par value of $0.001 per share; 200,000,000 and 100,000,000 shares authorized as of December 31, 2020 and 2019, respectively; 17,548,263 and 702,510 shares issued and outstanding as of December 31, 2020 and 2019, respectively	18	1
Additional paid-in capital	180,526	5,872
Accumulated other comprehensive income	4	32
Accumulated deficit	(96,113)	(54,753)
Total stockholders' equity (deficit)	84,435	(48,848)
Total liabilities, convertible preferred stock and stockholders’ equity (deficit)	$ 90,842	33,298
Series Seed Convertible Preferred Stock
Current liabilities:
Convertible preferred stock		1,460
Series A Convertible Preferred Stock
Current liabilities:
Convertible preferred stock		30,729
Series B Convertible Preferred Stock
Current liabilities:
Convertible preferred stock		$ 45,575

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Convertible preferred stock, par value		$ 0.001
Convertible preferred stock, shares authorized		70,378,661
Convertible preferred stock, shares issued		60,533,313
Convertible preferred stock, shares outstanding		60,533,313
Liquidation value		$ 80,061
Preferred stock, par value	$ 0.001
Preferred stock, shares authorized	10,000,000	0
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	200,000,000	100,000,000
Common stock, shares issued	17,548,263	702,510
Common stock, shares outstanding	17,548,263	702,510
Series Seed Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.001	$ 0.001
Convertible preferred stock, shares authorized	0	2,712,960
Convertible preferred stock, shares issued	0	2,712,960
Convertible preferred stock, shares outstanding	0	2,712,960
Liquidation value	$ 0
Series A Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.001	$ 0.001
Convertible preferred stock, shares authorized	0	31,499,040
Convertible preferred stock, shares issued	0	31,499,040
Convertible preferred stock, shares outstanding	0	31,499,040
Series B Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.001	$ 0.001
Convertible preferred stock, shares authorized	0	36,166,661
Convertible preferred stock, shares issued	0	26,321,313
Convertible preferred stock, shares outstanding	0	26,321,313

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Operating expenses:
Research and development	$ 32,154	$ 19,009
General and administrative	9,544	5,107
Total operating expenses	41,698	24,116
Loss from operations	(41,698)	(24,116)
Total other income:
Interest income	483	578
Other income (expense)	(145)	75
Total other income, net	338	653
Net loss	(41,360)	(23,463)
Accretion of Series B convertible preferred stock	(7,858)
Net loss attributable to common stockholders—basic and diluted	$ (49,218)	$ (23,463)
Net loss per share applicable to common stockholders—basic and diluted	$ (3.53)	$ (33.40)
Weighted-average common shares outstanding—basic and diluted	13,924,730	702,455
Comprehensive loss:
Net loss	$ (41,360)	$ (23,463)
Other comprehensive loss:
Unrealized gain (loss) on investments, net	(28)	32
Comprehensive loss	$ (41,388)	$ (23,431)

Consolidated Statements of Conv

Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	CONVERTIBLE PREFERRED STOCK SERIES SEED	CONVERTIBLE PREFERRED STOCK SERIES A	CONVERTIBLE PREFERRED STOCK SERIES B	COMMON STOCK	ADDITIONAL PAID-IN CAPITAL	ACCUMULATED OTHER COMPREHENSIVE INCOME	ACCUMULATED DEFICIT
Beginning balance at Dec. 31, 2018	$ (26,316)				$ 1	$ 4,973		$ (31,290)
Beginning balance, shares at Dec. 31, 2018					702,510
Beginning balance, convertible preferred stock at Dec. 31, 2018		$ 1,460	$ 30,729
Beginning balance, convertible preferred stock, shares at Dec. 31, 2018		2,712,960	31,499,040
Issuance of Series B convertible preferred stock, net of issuance costs and beneficial conversion charge				$ 45,575
Issuance of Series B convertible preferred stock, net of issuance costs and beneficial conversion charge, shares				26,321,313
Stock-based compensation expense	899					899
Unrealized gain (loss) on investments	32						$ 32
Net loss	(23,463)							(23,463)
Ending balance at Dec. 31, 2019	(48,848)				$ 1	5,872	32	(54,753)
Ending balance, shares at Dec. 31, 2019					702,510
Ending balance, convertible preferred stock at Dec. 31, 2019	$ 77,764	$ 1,460	$ 30,729	$ 45,575
Ending balance, convertible preferred stock, shares at Dec. 31, 2019	60,533,313	2,712,960	31,499,040	26,321,313
Issuance of Series B convertible preferred stock, net of issuance costs and beneficial conversion charge	$ 7,858			$ 9,271		7,858
Issuance of Series B convertible preferred stock, net of issuance costs and beneficial conversion charge, shares				9,845,348
Accretion of Series B converted preferred stock	(7,858)					(7,858)
Accretion of Series B converted preferred stock				$ 7,858
Conversion of convertible preferred stock into common stock	94,893	$ (1,460)	$ (30,729)	$ (62,704)	$ 11	94,882
Conversion of convertible preferred stock into common stock, shares		(2,712,960)	(31,499,040)	(36,166,661)	11,172,955
Initial public offering, net of underwriting discounts, commissions and offering costs	76,526				$ 6	76,520
Initial public offering, net of underwriting discounts, commissions and offering costs, shares					5,405,000
Exercise of stock options and issuance of stock under the Employee Stock Purchase Plan	1,021					1,021
Exercise of stock options and issuance of stock under the Employee Stock Purchase Plan, shares					267,798
Stock-based compensation expense	2,231					2,231
Unrealized gain (loss) on investments	(28)						(28)
Net loss	(41,360)							(41,360)
Ending balance at Dec. 31, 2020	$ 84,435				$ 18	$ 180,526	$ 4	$ (96,113)
Ending balance, shares at Dec. 31, 2020					17,548,263
Ending balance, convertible preferred stock, shares at Dec. 31, 2020		0	0	0

Consolidated Statements of Co_2

Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Convertible preferred stock, par value		$ 0.001
Common stock, par value	$ 0.001	0.001
Initial Public Offering
Underwriting discounts, commissions and offering costs	$ 3,902
CONVERTIBLE PREFERRED STOCK SERIES SEED
Convertible preferred stock, par value	$ 0.001	0.001
CONVERTIBLE PREFERRED STOCK SERIES A
Convertible preferred stock, par value	0.001	0.001
CONVERTIBLE PREFERRED STOCK SERIES B
Convertible preferred stock, par value	$ 0.001	$ 0.001
Stock issuance costs	$ 20	$ 274
COMMON STOCK
Common stock, par value	$ 0.001	$ 0.001

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net loss	$ (41,360)	$ (23,463)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	2,231	899
Depreciation expense	97	33
Amortization and accretion on investments	122	(19)
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(465)	(1,394)
Other assets	(60)	(88)
Accounts payable	313	750
Accrued expenses and other current liabilities	1,748	1,305
Deferred rent	(24)	100
Net cash used in operating activities	(37,398)	(21,877)
Cash flows from investing activities:
Proceeds from maturities and sales of short-term investments	47,500
Purchases of short-term investments	(64,203)	(23,920)
Purchases of property and equipment	(18)	(140)
Net cash used in investing activities	(16,721)	(24,060)
Cash flows from financing activities:
Proceeds from initial public offering, net of underwriting discounts, commissions and offering costs	80,427
Proceeds from exercise of options	1,022
Payment of issuance costs	(1,718)	(1,996)
Net cash provided by financing activities	96,881	43,579
Net increase in cash, cash equivalents and restricted cash	42,762	(2,358)
Cash, cash equivalents and restricted cash, beginning of period	5,024	7,382
Cash, cash equivalents and restricted cash, end of period	47,786	5,024
Supplemental disclosure of non-cash investing and financing activities:
Conversion of convertible preferred stock into common stock	94,893
Accretion of redeemable convertible preferred stock to redemption value	(7,858)
Reclassification of deferred offering costs from other assets to additional paid-in capital	(2,144)
Deferred offering costs included in accounts payable and accrued expenses		60
Property and equipment purchases included in accrued expenses	12	335
Unrealized loss on investments	(28)
CONVERTIBLE PREFERRED STOCK SERIES B
Cash flows from financing activities:
Proceeds from issuance of convertible preferred stock, net of issuance costs	$ 17,150	$ 45,575

Consolidated Statements of Ca_2

Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement Of Cash Flows [Abstract]
Cash and cash equivalents	$ 47,698	$ 4,936
Restricted cash (included in other assets)	88	88
Total cash, cash equivalents and restricted cash	$ 47,786	$ 5,024	$ 7,382

Nature of the Business

Nature of the Business	12 Months Ended
	Dec. 31, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of the Business	1. Nature of the Business IMARA Inc. (“IMARA” or the “Company”) is a clinical-stage biopharmaceutical company dedicated to developing and commercializing novel therapeutics to treat rare inherited genetic disorders of hemoglobin, known as hemoglobinopathies, which have significant unmet medical need. The Company was incorporated in January 2016 under the laws of the State of Delaware, and its principal offices are in Boston, Massachusetts. The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry, including but not limited to, risks associated with completing preclinical studies and clinical trials, receiving regulatory approvals for product candidates, development by competitors of new biopharmaceutical products, dependence on key personnel, protection of proprietary technology, compliance with government regulations and the ability to secure additional capital to fund operations. The Company’s sole product candidate currently under development, IMR-687, as well as any other product candidates the Company may develop, will require significant additional research and development efforts, including preclinical and clinical testing and regulatory approval, prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will realize revenue from product sales. In February 2020, the Company effected a 1-for-6.299 reverse stock split of the Company’s issued and outstanding shares of common stock and a proportional adjustment to the existing conversion ratios for each of the Company’s outstanding series of Series Seed convertible preferred stock (“Series Seed Preferred Stock”), Series A convertible preferred stock (“Series A Preferred Stock”), Series B convertible preferred stock (“Series B Preferred Stock”), collectively referred to as “Preferred Stock.”. All share and per share amounts in the consolidated financial statements and notes thereto have been retroactively adjusted for all periods presented to give effect to the reverse stock split, including reclassifying an amount equal to the change in par value of common stock to additional paid-in capital. On February 25, 2020, the Company issued and sold 1,562,994‬ shares of Series B Preferred Stock at a price of $10.9722 per share, upon a waiver of specified milestone conditions from the holders of a majority of the shares then held by holders of Series B Preferred Stock, and raised approximately $17.1 million in net proceeds after deducting less than $0.1 million of issuance costs. On March 16, 2020, the Company completed an initial public offering (“IPO”) of its common stock and issued and sold 4,700,000 shares of common stock at a public offering price of $16.00 per share, resulting in gross proceeds of $75.2 million. On April 13, 2020, the Company issued and sold an additional 705,000 shares of common stock pursuant to the exercise of the underwriters’ option to purchase additional shares for aggregate gross proceeds of $11.3 million. Inclusive of the exercise by the underwriters of their option to purchase additional shares, the Company received approximately $76.5 million in net proceeds from the IPO after deducting $10.0 million of underwriting discounts and commissions and offering expenses. Upon the closing of the IPO, all 70,378,661 shares of outstanding Preferred Stock automatically converted into 11,172,955 shares of common stock. Upon conversion of the convertible Preferred Stock, the Company reclassified the carrying value of the convertible Preferred Stock to common stock and additional paid-in capital. Liquidity The Company has incurred recurring negative cash flows since inception and has funded its operations primarily from the sale of Preferred Stock. As of December 31, 2020, the Company had cash, cash equivalents, and investments of $88.2 million and an accumulated deficit of $96.1 million. The Company expects its operating losses and negative operating cash flows to continue into the foreseeable future as it continues to expand its research and development efforts. The Company believes its cash, cash equivalents and investments will be sufficient to fund its operating expenses and capital expenditure requirements for at least twelve months from the date of filing this Annual Report on Form 10-K. The Company will need additional funding to support its planned operating activities. There can be no assurances, however, that the current operating plan will be achieved or that additional funding will be available on terms acceptable to the Company, or at all. If the Company is unable to obtain sufficient funding, it could be required to delay its development efforts, limit activities and reduce research and development costs, which could adversely affect its business prospects.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of presentation The accompanying consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ASC”) and as amended by Accounting Standards Updates of the Financial Accounting Standards Board (“FASB”). Principles of Consolidation The accompanying consolidated financial statements of the Company include the accounts of its wholly owned subsidiaries, IMARA Security Corporation and IMARA E.U. Limited. All intercompany transactions and balances have been eliminated in consolidation. Use of Estimates The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of expenses during the reporting periods. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, accrued research and development expenses, stock-based compensation expense, the fair value of the common stock and Preferred Stock and income taxes. Actual results could differ materially from those estimates. Segments Operating segments are defined as components of an enterprise for which separate and discrete information is available for evaluation by the chief operating decision-maker in deciding how to allocate resources and assess performance. The Company has one operating segment. The Company’s chief operating decision maker, its Chief Executive Officer, manages the Company’s operations on a consolidated basis for the purpose of allocating resources. All of the Company’s long-lived assets are held in the United States. Cash and Cash Equivalents The Company considers all highly liquid investments that are readily convertible into cash with original maturities of three months or less from the date of purchase to be cash equivalents. Cash and cash equivalents include cash held in banks and amounts held in money market funds. Cash equivalents are stated at cost, which approximates market value. Restricted Cash Restricted cash of less than $0.1 million as of December 31, 2020 and December 31, 2019, represents a letter of credit held as collateral in support of the Company’s facility lease. Restricted cash is included as a component of other assets on the Company’s consolidated balance sheets. Investments The Company’s investments are maintained by investment managers and consist of corporate debt securities and commercial paper with original maturities of over 90 days, all of which are considered available-for-sale securities. The Company classifies its available-for-sale securities as short-term investments on the consolidated balance sheets, even though the stated maturity date may be one year or more beyond the current balance sheet date, as the Company views those securities as available for use in current operations, if needed. Available-for-sale securities are carried at fair value with their unrealized gains and losses included in accumulated other comprehensive income within stockholders’ equity (deficit), until such gains and losses are realized in other income (expense) within the consolidated statements of operations and comprehensive loss or until an unrealized loss is considered other-than-temporary. The Company evaluates its investments with unrealized losses for other-than-temporary impairment. When assessing investments for other-than-temporary declines in value, the Company considers such factors as, among other things, how significant the decline in value is as a percentage of the original cost, how long the market value of the investment has been less than its original cost, the Company’s ability and intent to retain the investment for a period of time sufficient to allow for any anticipated recovery in fair value and market conditions. If the Company determines from this analysis that it does not expect to receive cash flows sufficient to recover the entire amortized cost of the security, a credit loss exists, the impairment is considered other-than-temporary and is recognized in the consolidated statements of operations and comprehensive loss. Deferred Offering Costs The Company capitalizes certain legal, professional, accounting and other third-party fees that are directly associated with in-process equity issuances as deferred offering costs until such equity issuances are consummated. After consummation of the equity issuance, these costs are recorded as a reduction in the capitalized amount associated with the equity issuance. Should the equity issuance be abandoned, the deferred offering costs will be expensed immediately as a charge to operating expenses in the consolidated statement of operations and comprehensive loss. On March 16, 2020, the Company completed its IPO; accordingly, the Company recognized the deferred offering costs of approximately $3.9 million as a reduction from gross proceeds associated with the IPO through additional paid-in capital in the accompanying consolidated balance sheet. Deferred offering costs classified in other assets on the accompanying consolidated balance sheet as of December 31, 2019 were $2.1 million. There were no deferred offering costs as of December 31, 2020. Concentrations of Credit Risk and Off-Balance Sheet Risk Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash, cash equivalents and investments. Periodically, the Company maintains deposits in accredited financial institutions in excess of federally insured limits. The Company deposits its cash in financial institutions that it believes have high credit quality and have not experienced any losses on such accounts and does not believe it is exposed to any unusual credit risk beyond the normal credit risk associated with commercial banking relationships. Such deposits have and will continue to exceed federally insured limits. The Company has not experienced any losses on its cash deposits. The Company’s available-for-sale investments primarily consist of high-grade corporate debt and commercial paper, and potentially subject the Company to concentrations of credit risk. The Company has adopted an investment policy that limits the amounts the Company may invest in any one type of investment and requires all investments held by the Company to be highly rated, thereby reducing credit risk exposure. As of December 31, 2020 and 2019, the Company had no off-balance sheet risk such as foreign exchange contracts, option contracts, or other hedging arrangements. Comprehensive Loss Comprehensive loss includes net loss and certain changes in stockholders’ equity (deficit) that are excluded from net loss. For the years ended December 31, 2020 and 2019, as a result of the Company’s investments in available-for-sale securities, the Company’s comprehensive loss includes unrealized gains and losses on those available-for-sale securities. Fair Value Measurements Certain assets and liabilities of the Company are carried at fair value under GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. • Level 3—Unobservable inputs that are supported by little or no market activity that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. An entity may choose to measure many financial instruments and certain other items at fair value at specified election dates. Subsequent unrealized gains and losses on items for which the fair value option has been elected will be reported in earnings. The carrying amounts reflected in the consolidated balance sheets for prepaid expenses and other current assets, accounts payable and accrued expenses approximate their fair values due to their short-term nature of these assets and liabilities. Property and Equipment, Net Property and equipment is stated at cost, net of accumulated depreciation. Depreciation is calculated using the straight-line method over the estimated useful lives of the assets, which are as follows: Estimated Useful Life Computer equipment and software 3 years Furniture and fixtures 5 years Laboratory equipment 5 years Leasehold improvements Shorter of useful life or remaining lease term Purchased assets that are not yet in service are recorded to construction-in-process and no depreciation expense is recorded. Once they are placed in service they are reclassified to the appropriate asset class. Upon the retirement or sale of an asset, the related cost and accumulated depreciation is removed from the accounts and any resulting gain or loss is recorded to other income (expense), net. Expenditures for maintenance and repairs are expensed as incurred. Deferred Rent Deferred rent consists of rent escalation payment terms, tenant improvement allowances and other incentives received from landlords related to the Company’s operating leases. Rent escalation represents the difference between actual operating lease payments due and straight-line rent expense, which is recorded by the Company over the term of the lease. Tenant improvement allowances and other incentives are recorded as deferred rent and amortized as a reduction of periodic rent expense, over the term of the applicable lease. Research and Development Expenses Research and development costs are expensed as incurred. Research and development expenses consist of costs incurred in performing research and development activities, including salaries, stock-based compensation and benefits, facilities costs, depreciation, third-party license fees, and external costs of outside vendors engaged to conduct preclinical development activities and clinical trials as well as to manufacture research and development materials. Non-refundable prepayments for goods or services that will be used or rendered for future research and development activities are deferred and capitalized. Such amounts are expensed as the goods are delivered or the related services are performed or until it is no longer expected that the goods will be delivered, or the services rendered. Costs incurred in obtaining technology licenses are recognized as research and development expense as incurred if the technology licensed has not reached technological feasibility and has no alternative future uses. Accrued Research and Development Expenses The Company has entered into various research and development related contracts with parties both inside and outside of the United States, including contracts with third-party contract research organizations and contract manufacturing organizations. These agreements are cancelable, and related payments are recognized as research and development expenses as incurred. The Company records accrued liabilities for estimated ongoing research costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes the progress of the studies or clinical trials, including the phase or completion of events, invoices received and contracted costs. Significant judgments and estimates are made in determining the accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates. To date, the Company’s historical accrual estimates have not been materially different from the actual costs. Patent Costs All patent-related costs incurred in connection with filing and prosecuting patent applications are expensed as incurred due to the uncertainty about the recovery of the expenditure and are classified as general and administrative expenses. Stock-Based Compensation The Company accounts for all stock-based awards granted to employees and non-employees as stock-based compensation expense at fair value. For stock-based awards issued to employees and members of the Company’s board of directors (the “Board”) for their services as a member of the Board, the Company measures the estimated fair value of the stock-based award on the date of grant. Since the Company’s initial public offering in March 2020, the fair value of the common stock has been determined based on the closing price of the Company’s stock on the date of grant. Prior to the Company’s initial public offering, the Company determined the fair value of the underlying common stock based on input from management and approved by the Board, which utilized the valuation of the Company’s enterprise value determined utilizing various methods including the back-solve method, the option-pricing method (“OPM”) or a hybrid of the probability-weighted expected return method (“PWERM”) and the OPM. The total enterprise value was then allocated to the various outstanding equity instruments, including the underlying common stock, utilizing the option-pricing model. For employee and non-employee awards, the Company recognizes compensation expense over the requisite service period, which is generally the vesting period of the respective award based on the grant date fair value of the award. For awards that include performance-based vesting conditions expense is recognized using the accelerated attribution method when the performance condition is deemed to be probable. The Company accounts for forfeitures as they occur. The Company determines the fair value of restricted stock awards in reference to the fair value of its common stock less any applicable purchase price. The fair value of each stock option grant is estimated on the date of grant using the Black-Scholes option-pricing model, which requires inputs based on certain subjective assumptions, including the expected stock price volatility, the expected term of the option, the risk-free interest rate for a period that approximates the expected term of the option and the Company’s expected dividend yield. The fair value of each restricted stock award is determined on the date of grant based on the fair value of the Company’s common stock on that same date. Given the Company’s limited trading history as a public company, the Company determines the volatility for awards granted based on an analysis of reported data for a group of guideline companies that issued options with substantially similar terms. The expected volatility has been determined using a weighted-average of the historical volatility measures of this group of guideline companies. The Company expects to continue to do so until such time as it has adequate historical data regarding the volatility of its own traded stock price. The expected term of the Company’s stock options granted to employees has been determined utilizing the “simplified” method for awards that qualify as “plain-vanilla” options. Under the simplified method, the expected term is presumed to be the midpoint between the vesting date and the end of the contractual term. The Company utilizes this method due to lack of historical exercise data and the plain nature of its stock-based awards. Prior to the Company’s IPO, the expected term of stock options granted to non-employees also used the “simplified” method. Following the Company’s IPO, the expected term of options granted to non-employees is determined by contractual term. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. The Company has not paid, and does not anticipate paying, cash dividends on its common stock; therefore, the expected dividend yield is assumed to be zero. The Company classifies stock-based compensation expense in its consolidated statements of operations and comprehensive loss in the same manner in which the award recipient’s cash compensation costs are classified. Income Taxes The Company accounts for income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in the financial statements or the Company’s tax returns. Under this method, deferred tax assets and liabilities are determined based on the differences between the consolidated financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Changes in deferred tax assets and liabilities are recorded in the provision for income taxes. The Company assesses the likelihood that its deferred tax assets will be recovered from future taxable income and, to the extent it believes, based upon the weight of available evidence, that it is more likely than not that all or a portion of the deferred tax assets will not be realized, a valuation allowance is established. The Company accounts for uncertain tax positions recognized in the consolidated financial statements by prescribing a more-likely-than-not threshold for financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. The provision for income taxes includes the effects of any resulting tax reserves, or unrecognized tax benefits, that are considered appropriate as well as the related net interest and penalties. Net Loss per Share Basic net loss per share is computed by dividing net loss by the weighted-average number of common shares outstanding during the period. Diluted net loss per share is computed using the weighted-average number of common shares outstanding during the period and, if dilutive, the weighted-average number of potential shares of common stock. Net loss per share attributable to common stockholders is calculated using the two-class method, which is an earnings allocation formula that determines net loss per share for the holders of the Company’s common shares and participating securities. The Company’s Preferred Stock contained participation rights in any dividend paid by the Company and is deemed to be a participating security. Net loss attributable to common stockholders and participating preferred shares are allocated to each share on an as-converted basis as if all of the earnings for the period had been distributed. The participating securities do not include a contractual obligation to share in losses of the Company and are not included in the calculation of net loss per share in the periods in which a net loss is recorded. Diluted net loss per share is computed using the more dilutive of (a) the two-class method or (b) the if-converted method. The Company allocates earnings first to preferred stockholders based on dividend rights and then to common and preferred stockholders based on ownership interests. The weighted-average number of common shares included in the computation of diluted net loss effect to all potentially dilutive common equivalent shares, including outstanding stock options and Preferred Stock. Common stock equivalent shares are excluded from the computation of diluted net loss per share if their effect is antidilutive. In periods in which the Company reports a net loss attributable to common stockholders, diluted net loss per share attributable to common stockholders is generally the same as basic net loss per share attributable to common stockholders since dilutive common shares are not assumed to have been issued if their effect is anti-dilutive. Recently Issued Accounting Pronouncements In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842), which, among other things, requires lessees to recognize an obligation to make lease payments arising from a lease, measured on a discounted basis, and a right-of-use asset, which is an asset that represents the lessee's right to use, or control the use of, a specified asset for the lease term. Expenses are recognized in the consolidated statement of operations in a manner similar to current accounting guidance. The Company expects to make an accounting policy election to not recognize an asset and liability for leases with a term of twelve months or less. The standard is effective for fiscal years beginning after December 15, 2021. The Company will early adopt the accounting standard effective January 1, 2021 using a modified retrospective approach, which applies the provisions of the new guidance at the effective date without adjusting the comparative periods presented. The Company is finalizing its evaluation of the impacts that the adoption of this accounting guidance will have on the consolidated financial statements and estimates approximately $1 million of right-to-use assets and lease liabilities will be recognized in the balance sheet upon adoption. In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments In July 2017, the FASB issued ASU 2017-11, Earnings Per Share (Topic 260), Distinguishing Liabilities from Equity (Topic 480), Derivatives and Hedging (Topic 815) I. Accounting for Certain Financial Instruments with Down Round Features II. Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with a Scope Exception . On August 5, 2020, the FASB issued ASU 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity

Fair Value of Financial Assets

Fair Value of Financial Assets and Liabilities	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value of Financial Assets and Liabilities	3. Fair Value of Financial Assets and Liabilities The following table presents information about the Company’s financial assets and liabilities measured at fair value on a recurring basis and indicates the level of the fair value hierarchy utilized to determine such fair values (in thousands): December 31, 2020 Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Other Observable Inputs Description Total (Level 1) (Level 2) (Level 3) Assets: Money market funds, included in cash and cash equivalents $ 41,208 $ 41,208 $ — $ — Marketable securities: Corporate debt securities 14,807 — 14,807 — Commercial paper 25,717 — 25,717 — Total financial assets $ 81,732 $ 41,208 $ 40,524 $ — December 31, 2019 Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Other Observable Inputs Description Total (Level 1) (Level 2) (Level 3) Assets: Money market funds, included in cash and cash equivalents $ 4,477 $ 4,477 $ — $ — Marketable securities: Corporate debt securities 5,772 — 5,772 — Commercial paper 18,199 — 18,199 — Total financial assets $ 28,448 $ 4,477 $ 23,971 $ — As of December 31, 2020 and 2019, the Company’s cash equivalents consisted of money market funds, classified as Level 1 financial assets, as these assets are valued using quoted market prices in active markets without any valuation adjustment. The financial assets valued based on Level 2 inputs consist of corporate debt securities and commercial paper, which consist of investments in highly-rated investment-grade securities. The Company estimates the fair values of these marketable securities by taking into consideration valuations obtained from third-party pricing sources. These pricing sources utilize industry standard valuation models, including both income and market-based approaches, for which all significant inputs are observable, either directly or indirectly, to estimate fair value. These inputs include market pricing based on real-time trade data for the same or similar securities, issuer credit spreads, benchmark yields, and other observable inputs. The Company validates the prices provided by its third-party pricing sources by understanding the models used, obtaining market values from other pricing sources and analyzing pricing data in certain instances. During the years ended December 31, 2020 and 2019, there were no transfers between fair value measurement levels.

Investments

Investments	12 Months Ended
	Dec. 31, 2020
Investments Debt And Equity Securities [Abstract]
Investments	4. Investments As of December 31, 2020, the Company had short-term investments consisting of corporate debt securities and commercial paper, which are considered to be available-for-sale investments. These are included in short-term investments on the consolidated balance sheets, even though the stated maturity date may be one year or more beyond the current balance sheet date, as the Company views those securities as available for use in current operations, if needed. The following table summarizes the Company’s investments as of December 31, 2020 and 2019 (in thousands): December 31, 2020 Amortized Cost Gross Unrealized Gains Gross Unrealized Loss Fair Value Current: Commercial paper $ 25,716 $ 1 $ — $ 25,717 Corporate debt securities 14,804 3 — 14,807 Total $ 40,520 $ 4 $ — $ 40,524 December 31, 2019 Amortized Cost Gross Unrealized Gains Gross Unrealized Loss Fair Value Current: Commercial paper $ 18,167 $ 32 $ — $ 18,199 Corporate debt securities 5,772 — — 5,772 Total $ 23,939 $ 32 $ — $ 23,971 As of December 31, 2020 and 2019, the Company had no available-for-sale securities in unrealized loss positions. The Company determined that there was no material change in the credit risk of its investments. As a result, the Company determined it did not hold any investments with an other-than-temporary impairment as of December 31, 2020 and 2019.

Property and Equipment, net

Property and Equipment, net	12 Months Ended
	Dec. 31, 2020
Property Plant And Equipment [Abstract]
Property and Equipment, net	5. Property and Equipment, net Property and equipment, net consisted of the following (in thousands): December 31, 2020 December 31, 2019 Property and equipment: Leasehold improvements $ 336 $ 339 Furniture and fixtures 143 136 Property and equipment $ 479 $ 475 Less: accumulated depreciation (130 ) (33 ) Property and equipment, net $ 349 $ 442 Depreciation expense was $0.1 million and less than $0.1 million for the years ended December 31, 2020 and 2019, respectively.

Accrued Expenses

Accrued Expenses	12 Months Ended
	Dec. 31, 2020
Payables And Accruals [Abstract]
Accrued Expenses	6. Accrued Expenses Accrued expenses consisted of the following (in thousands): December 31, 2020 December 31, 2019 Accrued research and development expenses $ 2,732 $ 1,106 Accrued compensation and benefits 1,090 802 Accrued professional services 355 330 Accrued other 99 302 Total accrued expenses $ 4,276 $ 2,540

License Agreements

License Agreements	12 Months Ended
	Dec. 31, 2020
License Agreements [Abstract]
License Agreements	7. License Agreements Agreement with Lundbeck In April 2016, the Company entered into a license agreement with Lundbeck (the “Lundbeck Agreement”) pursuant to which Lundbeck granted the Company the following licenses within the field of prevention, treatment or diagnosis of hemoglobinopathy disorders and/or other diseases or disorders, including those directly or indirectly related to hemoglobinopathies: (1) an exclusive, royalty-bearing license to certain patent rights and certain know-how owned or otherwise controlled by Lundbeck (“Licensed Technology”) to research, develop, make, use, sell, and commercialize products (“Licensed Products”) from PDE9 inhibitors, which included IMR-687 (“Licensed Compounds”); (2) a non-exclusive license to the Licensed Technology to make, research, develop, and use such Licensed Technology to enable research and development, with certain restrictions; and (3) a sublicensing right that allows the Company to grant sublicenses to third parties to use the Licensed Technology subject to the certain terms detailed in the Lundbeck Agreement. Under the Lundbeck Agreement, the Company is subject to certain achievement dates for development milestones as defined in the agreement. The regulatory milestones due under the Lundbeck Agreement depend on the products being developed. Development milestones due under the Lundbeck Agreement with respect to the Licensed Compounds total up to $23.5 million, and, for any products that contain PDE9 inhibitors other than Licensed Compounds, total up to $11.8 million. The Company also agreed to pay tiered royalties based on net sales of all products licensed under the agreement in the low single-digit percentages. To date, pursuant to the license agreement, the Company has made cash payments to Lundbeck of $1.8 million consisting of an upfront payment and ongoing milestone payments, which are recorded as research and development expense. No payments were made during the year ended December 31, 2020. As partial consideration for the license, the Company issued 167,523 shares of common stock to Lundbeck in 2016, which represented 8.0% of the Company’s then outstanding equity pursuant to a restricted stock agreement. The shares were fully vested on the date of issuance. The Lundbeck Agreement can be terminated by the Company at any time with 180 days’ written notice. The Company or Lundbeck may terminate the agreement by written notice within a specified period of time in the event of a material breach.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	8. Commitments and Contingencies Lease Agreements In 2016, the Company entered into an agreement for office space located in Cambridge, Massachusetts, which was a month-to-month lease, with a related party (see Note 14). The Company recorded rent expense of $0.2 million and $0.2 million during the years ended December 31, 2020 and 2019, respectively. In May 2019, the Company entered into a new operating lease agreement for office space totaling 4,210 square feet, located in Boston, Massachusetts with a 62-month term. The lease includes a rent escalation clause which results in cash rental payments of approximately $0.3 million annually. Rent expense is being recognized on a straight-line basis over the lease term. In addition to the base rent, the Company is also responsible for its share of operating expenses, electricity and real estate taxes, in accordance with the terms of the Lease Agreement. The Company provided a security deposit of approximately $0.1 million during the year ended December 31, 2019, which is included as a component of other assets on the Company’s consolidated balance sheets. The Company occupied the space in August 2019 and commenced recognition of rent expense. The following table summarizes the future minimum lease payments due under the Company’s operating leases as of December 31, 2020 exclusive of amounts prepaid by the Company (in thousands): December 31, 2020 2021 273 2022 278 2023 284 2024 229 $ 1,064 Legal Proceedings The Company may from time to time be party to litigation arising in the ordinary course of business. The Company was not subject to any material legal proceedings during the years ended December 31, 2020 and 2019, and no material legal proceedings are currently pending or, to the best of its knowledge, threatened. Indemnification Agreements The Company enters into standard indemnification agreements in the ordinary course of business. Pursuant to the indemnification agreements, the Company agrees to indemnify, hold harmless, and to reimburse the indemnified party for losses suffered or incurred by the indemnified party, generally the Company’s business partners, in connection with any U.S. patent or any copyright or other intellectual property infringement claim by any third-party with respect to the Company’s products. The term of these indemnification agreements is generally perpetual any time after execution of the agreement. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is unlimited. The Company has never incurred costs to defend lawsuits or settle claims related to these indemnification agreements.

Convertible Preferred Stock

Convertible Preferred Stock	12 Months Ended
	Dec. 31, 2020
Temporary Equity Disclosure [Abstract]
Convertible Preferred Stock	9. Convertible Preferred Stock Prior to the sale of common stock in connection with its IPO, the Company had funded its operations primarily with proceeds from the sale of Preferred Stock. In March 2019, the Company issued Series B Preferred Stock and, in connection with such issuance, restated its certificate of incorporation (the “Second Amended and Restated Certificate of Incorporation” or “Second A&R COI”) such that as of December 31, 2019, the authorized capital stock of the Company included 70,378,661 shares of $0.001 par value Preferred Stock, of which 36,166,661 are designated as Series B Preferred Stock, 31,499,040 have been designated as Series A Preferred Stock, and 2,712,960 have been designated as Series Seed Preferred Stock. In March 2019, the Company issued and sold 25,316,663 shares of Series B Preferred Stock, at a price of $1.7419 per share. The terms of the Series B Preferred Stock Purchase Agreement included the obligation of the investors to purchase, and the Company to sell, 10,849,998 additional shares of Series B Preferred Stock at a purchase price of $1.7419 per share, contingent upon the achievement of a specified pre-designated milestone event. The Company concluded that the tranche feature is not a freestanding financial instrument as the right to purchase the future tranche is not legally detachable from the shares of Series B Preferred Stock. The pre-designated milestone event was not achieved and as such, the milestone tranche closing may take place within 18 months of the initial closing upon a waiver from the holders of a majority of the shares purchased at the initial closing. In addition, any Series B Preferred Stock investor has an option to purchase all or some of its milestone shares prior to any waiver of the milestone conditions. In May 2019, one of the investors exercised this option to purchase 1,004,650 of its milestone shares prior to the milestone closing, at a purchase price of $1.7419 per share. At initial issuance and subsequent closing, the Company concluded that no beneficial conversion features were present. On February 25, 2020, the Company raised $17.1 million in net proceeds from the sale of 1,562,994‬ shares of Series B Preferred Stock, at a price of $10.9722 per share, upon a waiver of specified milestone conditions from the holders of a majority of the shares then held by the holders of Series B Preferred Stock. Upon issuance, each share of Series B Preferred Stock included an embedded beneficial conversion feature as the estimated fair value of the Company’s common stock on the date of issuance of the Series B Preferred Stock was higher than the effective conversion price of the Series B Preferred Stock of $10.9722 per share. Given the proximity of the issuance to the Company’s public offering, the Company utilized the $16.00 public offing price of its common stock Upon the completion of the IPO on March 16, 2020, all 70,378,661 shares of outstanding Preferred Stock automatically converted into 11,172,955 shares of common stock. As of December 31, 2019, convertible preferred stock consisted of the following (in thousands, except share data): December 31, 2019 Preferred Stock Authorized Preferred Stock Issued and Outstanding Carrying Value Liquidation Value Common stock Issuable Upon Conversion Series Seed Preferred Stock 2,712,960 2,712,960 $ 1,460 $ 2,713 430,693 Series A Preferred Stock 31,499,040 31,499,040 30,729 31,499 5,000,623 Series B Preferred Stock 36,166,661 26,321,313 45,575 45,849 4,178,645 70,378,661 60,533,313 $ 77,764 $ 80,061 9,609,961 Liquidation Rights In the event of any voluntary or involuntary liquidation event, dissolution, winding up of the Company or upon the occurrence of certain other deemed liquidation events described in the Company’s charter, each holder of the then outstanding Series B Preferred Stock was entitled to receive, prior and in preference to any distributions to the holders of Series A Preferred Stock, Series Seed Preferred Stock and common stock, an amount equal to $1.7419 per share (adjusted in the event of any stock dividend, stock split, combination or other similar recapitalization) plus any declared but unpaid dividends thereon. After the payment of all preferential amounts to the holders of Series B Preferred Stock, each holder of the then outstanding Series A Preferred Stock was entitled to receive, prior and in preference to any distributions to the holders of Series Seed Preferred Stock and common stock, an amount equal to $1.00 per share (adjusted in the event of any stock dividend, stock split, combination or other similar recapitalization) plus any declared but unpaid dividends thereon. After the payment of all preferential amounts to the holders of Series A Preferred Stock, each holder of the then outstanding Series Seed Preferred Stock was entitled to receive, prior and in preference to any distributions to the holders of common stock, an amount equal to $1.00 per share (adjusted in the event of any stock dividend, stock split, combination or other similar recapitalization) plus any declared but unpaid dividends thereon. After payments were made in full to the holders of the Preferred Stock, then, to the extent available, the remaining amounts would have been distributed among the holders of the shares of common stock, Series A Preferred Stock and Series B Preferred Stock, pro rata based on the number of shares held by each holder (determined on an as-converted basis). Conversion Pursuant to the Second A&R COI, each share of Preferred Stock is convertible into common stock, at any time, at the option of the holder, and without the payment of additional consideration, at the applicable conversion ratio then in effect for each series of Preferred Stock. In addition, each share of Preferred Stock will be automatically converted into common stock at the applicable conversion ratio then in effect for each series of Preferred Stock upon either (i) the closing of a firm commitment underwritten public offering of its common stock at a price per share of at least $2.6129 per share (subject to adjustment for any stock split, combination or similar recapitalization) resulting in $60.0 million or more of gross offering proceeds to the Company, or (ii) the date and time, or the occurrence of an event, specified by vote or written consent of the requisite holders of Preferred Stock. Redemption Upon certain change in control events that are outside of the Company’s control, including liquidation, sale or transfer of control of the Company, holders of the Preferred Stock could have caused redemption of the Preferred Stock. Shares of Preferred Stock must be redeemed by the Company in an amount equal to the liquidation preference for each series of Preferred Stock.

Stockholders' Equity (Deficit)

Stockholders' Equity (Deficit)	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Stockholders' Equity (Deficit)	10. Stockholders’ Equity (Deficit) On August 13, 2019, the Company’s board of directors, and on February 26, 2020, the Company’s stockholders, approved the Company’s restated certificate of incorporation, which became effective upon closing of the IPO on March 16, 2020, to authorize 10,000,000 shares of undesignated preferred stock, $0.001 per share par value, and to increase the number of authorized shares of common stock from 100,000,000 to 200,000,000 shares, $0.001 per share par value. Common stockholders are entitled to receive dividends, as may be declared by the Board, if any, subject to the preferential dividend rights of any preferred stock then outstanding. Through December 31, 2020, no cash dividends have been declared or paid. As of December 31, 2020, 10,000,000 shares of preferred stock were authorized and no shares of preferred stock were issued or outstanding. As of December 31, 2020 and December 31, 2019, the Company has reserved for future issuance the following shares of common stock: December 31, 2020 December 31, 2019 Conversion of outstanding preferred stock — 9,609,961 Shares reserved for future issuance under the 2016 Stock Incentive Plan — 228,852 Shares reserved for future issuance under the 2020 Equity Incentive Plan 1,110,675 — Shares reserved for future issuance under the 2020 Employee Stock Purchase Plan 191,363 — 1,302,038 9,838,813

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2020
Compensation Related Costs [Abstract]
Stock-Based Compensation	11. Stock-Based Compensation 2016 Stock Incentive Plan The Company’s 2016 Stock Incentive Plan, (the “2016 Plan”) provided for the grant of restricted stock, restricted stock units, stock appreciation rights, incentive stock options, non-statutory stock options and other stock-based awards to employees, officers, members of the Board, consultants and advisors of the Company. As of December 31, 2019, the number of shares of common stock authorized to be issued under the 2016 Plan was 2,091,969, of which 228,852 shares remained available for future grants as of December 31, 2019. As of the effective date of the 2020 Equity Incentive Plan, no shares remained available for future issuance under the 2016 Plan. Any options or awards outstanding under the 2016 Plan remain outstanding and effective. 2020 Equity Incentive Plan On October 1, 2019, the Company’s board of directors adopted, and on February 26, 2020 the Company’s stockholders approved, the 2020 Equity Incentive Plan (the “2020 Plan”), which became effective on March 11, 2020. The 2020 Plan provides for the grant of incentive stock options, non-qualified stock options, stock appreciation rights, restricted stock awards, restricted stock units and other stock-based awards. The number of shares reserved for issuance under the 2020 Plan is the sum of: (1) 1,220,283 shares of the Company’s common stock; plus (2) the number of shares (up to a maximum of 2,091,969 shares) equal to the sum of (x) 228,852 shares, which represents the Company’s common stock reserved for issuance under the 2016 Plan that remained available for grant under the 2016 Plan as of March 11, 2020 and (y) the number of shares of the Company’s common stock subject to outstanding awards granted under the 2016 Plan that expire, terminate or are otherwise surrendered, cancelled, forfeited or repurchased by the Company at their original issuance price pursuant to a contractual repurchase right. The number of shares reserved shall be annually increased on the first day of each fiscal year, beginning with the fiscal year ending December 31, 2021 and continuing until, and including, the fiscal year ending December 31, 2030, equal to the lesser of (i) 4% of the number of shares of the Company’s common stock outstanding on the first day of such fiscal year and (ii) an amount determined by the Company’s board of directors. No more than 8,541,982 shares of common stock may be issued as incentive stock options under the 2020 Plan. The shares of common stock underlying any awards that expire, terminate, or are otherwise surrendered, cancelled, forfeited or repurchased by the Company under the 2016 Plan or the 2020 Plan will be added back to the shares of common stock available for issuance under the 2020 Plan. As of December 31, 2020, there were 1,110,675 shares available for future issuance under the 2020 Plan. For financial reporting purposes, the Company performed common stock valuations with the assistance of a third-party specialist through October 23, 2019 to determine stock-based compensation expense for stock options. Upon completion of the IPO, the fair value of the common stock on the grant date was based on the closing price of the stock on the Nasdaq Global Select Market on the date of grant. The following table summarizes the Company’s stock option activity: Number of Shares Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (in years) Aggregate Intrinsic Value (in thousands) Outstanding as of December 31, 2019 1,863,117 $ 4.60 8.90 $ 15,151 Granted 759,139 19.80 Exercised (265,945 ) 4.34 Forfeited (420,679 ) 8.02 Outstanding as of December 31, 2020 1,935,632 $ 9.85 8.14 $ 24,260 Options vested and exercisable as of December 31, 2020 602,986 $ 4.34 6.42 $ 10,678 The aggregate intrinsic value of options is calculated as the difference between the exercise price of the stock options and the fair value of the Company’s common stock for those stock options that had exercise prices lower than the fair value of the common stock as of the end of the period. The weighted-average grant date fair value of the Company’s stock options granted during the years ended December 31, 2020 and 2019 was $12.95 and $3.46, respectively. The assumptions that the Company used to determine the grant date fair value of stock options granted to employees, non-employees and members of the Board during the years ended December 31, 2020 and 2019 were as follows, presented on a weighted-average basis : Year Ended December 31, 2020 2019 Expected term (in years) 6.17 6.11 Expected volatility 74.7 % 69.3 % Expected dividend yield 0.00 % 0.00 % Risk-free interest rate 0.52 % 2.18 % Performance-based awards The Company granted stock options to purchase an aggregate of 220,928 shares of common stock to certain employees, officers and consultants and advisors of the Company on May 16, 2019, June 5, 2019 and June 21, 2019, which contain performance-based vesting criteria. Vesting of these options was contingent on the closing of the second tranche of Series B Preferred Stock financing. Stock-based compensation expense associated with performance-based stock options is recognized if the performance conditions are considered probable of being achieved, using management’s best estimates. As a result of the performance condition being met on February 25, 2020, these options will vest as to 25% of the shares underlying each option on February 25, 2021 and as to the remainder of the shares in equal quarterly installments for three years thereafter. The Company recognized stock-based compensation expense of $0.3 million for these options during the year ended December 31, 2020. Stock-Based Compensation Stock-based compensation expense included in the Company’s consolidated statements of operations and comprehensive loss is as follows (in thousands): Year Ended December 31, 2020 2019 Research and development $ 1,490 $ 301 General and administrative 741 598 Total stock-based compensation expense $ 2,231 $ 899 As of December 31, 2020, total unrecognized compensation cost related to the unvested stock-based awards was $9.5 million, to be recognized over a weighted-average period of 3.22 years. 2020 Employee Stock Purchase Plan On October 1, 2019, the Company’s board of directors adopted, and on February 26, 2020, the Company’s stockholders approved the 2020 Employee Stock Purchase Plan (the “2020 ESPP”), which became effective on March 11, 2020. The 2020 ESPP permits eligible employees who elect to participate, in six-month offering periods, to purchase shares of common stock through payroll deductions at a price equal to 85% of the fair market value of the common stock on the first or last business day of each applicable six-month offering period, whichever is lower. Purchase dates under the ESPP occur on or about June 14 and December 14 each year. The 2020 ESPP initially provides participating employees with the opportunity to purchase up to an aggregate of 193,216 shares of the Company’s common stock. The number of shares of the Company’s common stock reserved for issuance under the 2020 ESPP will automatically increase on the first day of each fiscal year, beginning with the fiscal year commencing on January 1, 2021 and continuing until, and including, the fiscal year commencing on January 1, 2031, in an amount equal to the lowest of (i) 386,432 shares of the Company’s common stock, (ii) 1% of the number of shares of the Company’s common stock outstanding on the first day of such fiscal year and (iii) an amount determined by the Company’s board of directors. During the year ended December 31, 2020, less than $0.1 million was withheld from employees, on an after-tax basis, in order to purchase 1,853 shares of the Company’s common stock. The Company recorded stock-based compensation expense related to the 2020 ESPP of less than $0.1 million. As of December 31, 2020, 191,363 shares of the Company’s common stock remained available for issuance under the 2020 ESPP. As of December 31, 2020, there was less than $0.1 million of total unrecognized stock-based compensation expense related to the ESPP. The expense is expected to be recognized over a period of 5.5 months.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	12. Income Taxes For the years ended December 31, 2020 and 2019, the Company did not record a current or deferred income tax expense or benefit due to current and historical losses incurred by the Company. The Company’s losses before income taxes consist solely of losses from domestic operations. On March 27, 2020, the United States enacted the Coronavirus Aid, Relief, and Economic Security Act (“CARES Act”). The Cares Act includes provisions relating to refundable payroll tax credits, deferment of the employer portion of certain payroll taxes, net operating loss carryback periods, alternative minimum tax credit refunds, modifications to the net interest deduction limitations and technical corrections to tax depreciation methods for qualified improvement property. The CARES Act also established a Paycheck Protection Program whereby certain small businesses are eligible for a loan to fund payroll expenses, rent, and related costs. The Company considered the provisions under the CARES Act and elected not to take advantage of the provisions of CARES Act as the effect of such provisions was not expected to have a material impact on the Company’s results of operations, cash flows and consolidated financial statements. A reconciliation of income tax expense (benefit) computed at the statutory federal income tax rate to income taxes as reflected in the consolidated financial statements is as follows: 2020 2019 Income taxes at U.S. statutory rate 21 % 21 % State income taxes 6 6 Tax Credit 7 3 Other 2 (1 ) Change in valuation allowance (36 ) (29 ) Total provision for income taxes 0 % 0 % Deferred taxes are recognized for temporary differences between the basis of assets and liabilities for financial statement and income tax purposes. The significant components of the Company’s deferred tax assets and liabilities as of December 31, 2020 and 2019 are comprised of the following (in thousands): Year Ended December 31, 2020 2019 Deferred tax assets Net operating loss carryforwards $ 24,657 $ 13,284 Tax credits carryforwards 3,948 1,020 Stock-based compensation 686 246 Amortization 545 611 Accruals 272 200 Lease incentive liability 17 21 Other 42 31 Total deferred tax assets 30,167 15,413 Valuation allowance (30,149 ) (15,385 ) Net deferred tax assets 18 28 Deferred tax liabilities Tenant improvement allowance (17 ) (21 ) Unrealized gains/losses on investments (1 ) (7 ) Total deferred tax liabilities (18 ) (28 ) Net deferred taxes $ — $ — The Company has evaluated the positive and negative evidence bearing upon its ability to realize its deferred tax assets, which are comprised primarily of net operating loss carryforwards and tax credits. Management has considered the Company’s history of cumulative net losses in the United States, estimated future taxable income and prudent and feasible tax planning strategies and has concluded that it is more likely than not that the Company will not realize the benefits of its U.S. federal and state deferred tax assets. Accordingly, a full valuation allowance has been established against these net deferred tax assets as of December 31, 2020 and 2019, respectively. The Company reevaluates the positive and negative evidence at each reporting period. The Company’s valuation allowance increased during 2020 by approximately $14.8 million primarily due to the generation of net operating loss and tax credit carryforwards. As of December 31, 2020 and 2019, the Company had U.S. federal net operating loss carryforwards of $91.7 million and $48.6 million, respectively, which may be available to offset future income tax liabilities. The 2017 Tax Cuts and Jobs Act (“TCJA”) will generally allow losses incurred after 2017 to be carried over indefinitely but will generally limit the net operating loss deduction to the lesser of the net operating loss carryover or 80% of a corporation’s taxable income (subject to Section 382 of the Internal Revenue Code of 1986, as amended). Also, there will be no carryback for losses incurred after 2017. Losses incurred prior to 2018 will generally be deductible to the extent of the lesser of a corporation’s net operating loss carryover or 100% of a corporation’s taxable income and be available for twenty years from the period the loss was generated. The Company has federal net operating losses generated following 2017 of $74.5 million, which do not expire. The federal net operating losses generated prior to 2018 of $17.2 million will expire at various dates through 2037. The CARES Act temporarily allows the Company to carryback net operating losses arising in 2018, 2019 and 2020 to the five prior tax years. In addition, net operating losses generated in these years could fully offset prior year taxable income without the 80% taxable income limitation under the TCJA. The Company has been generating losses since its inception. As such, the net operating loss carryback provision under the CARES Act is not applicable to the Company. As of December 31, 2020 and 2019, the Company also had U.S. state net operating loss carryforwards of $85.5 million and $48.9 million, respectively, which may be available to offset future income tax liabilities and expire at various dates through 2040. As of December 31, 2020 and 2019, the Company had federal tax credit carryforwards of approximately $3.6 million and $0.9 million, respectively, available to reduce future tax liabilities which expire at various dates through 2040. As of December 31, 2020 and 2019, the Company had state research and development tax credit carryforwards of approximately $0.4 million and $0.1 million, respectively, available to reduce future tax liabilities which expire at various dates through 2035. Utilization of the U.S. federal and state net operating loss and research and development and orphan drug credit carryforwards may be subject to a substantial annual limitation under Sections 382 and 383 of the Internal Revenue Code of 1986, as amended, and corresponding provisions of state law, due to ownership changes that have occurred previously or that could occur in the future. These ownership changes may limit the amount of net operating loss and research and development credit carryforwards that can be utilized annually to offset future taxable income and tax liabilities, respectively. The Company has not completed a study to assess whether a change of ownership has occurred, or whether there have been multiple ownership changes since its formation, due to the significant cost and complexity associated with such a study. Any limitation may result in expiration of a portion of the net operating loss carryforwards or research and development and orphan drug credit carryforwards before utilization. Further, until a study is completed by the Company and any limitation is known, no amounts are being presented as an uncertain tax position. The Company has not, as of yet, conducted a study of research and development and orphan drug credit carryforwards. Such a study, once undertaken by the Company, may result in an adjustment to the Company’s research and development and orphan drug credit carryforwards; however, until a study is completed and any adjustment is known, no amounts are being presented as an uncertain tax position. A full valuation allowance has been provided against the Company’s research and development and orphan drug credits and, if an adjustment is required, this adjustment would be offset by an adjustment to the valuation allowance. Thus, there would be no impact to the balance sheet or statement of operations if an adjustment is required. The Company files tax returns in the United States and Massachusetts. The Company is subject to U.S. federal and state tax examinations by tax authorities for years 2017 through present. As of December 31, 2020 and 2019, the Company has recorded no liability for unrecognized tax benefits, interest, or penalties related to federal and state income tax matters and there currently no pending tax examinations. The Company will recognize interest and penalties related to uncertain tax positions in income tax expense.

Net Loss Per Share

Net Loss Per Share	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Net Loss Per Share	13. Net Loss Per Share The following table sets forth the computation of the Company’s basic and diluted net loss per share for the years ended December 31, 2020 and 2019 (in thousands, except share and per share amounts): Year Ended December 31, 2020 2019 Numerator: Net loss attributable to common stockholders—basic and diluted $ (49,218 ) $ (23,463 ) Denominator: Weighted-average number of common shares used in net loss per share—basic and diluted 13,924,730 702,455 Net loss per share—basic and diluted $ (3.53 ) $ (33.40 ) As of December 31, 2020 and 2019, the Company’s potentially dilutive securities were Preferred Stock, shares reserved for issuance under the ESPP and stock options, which have been excluded from the computation of diluted net loss per share attributable to common stockholders for the years ended December 31, 2020 and 2019, as the effect would be to reduce the net loss per share. All the Company’s restricted stock was vested as of December 31, 2019. Net loss applicable to common stockholders for the year ended December 31, 2020 did not equal net loss due to the accretion of the beneficial conversion feature of Series B Preferred Stock in the amount of $7.9 million. The beneficial conversion feature was initially recorded as a discount on the Series B Preferred Stock with a corresponding amount recorded to Additional Paid-in Capital. The discount on the Series B Preferred Stock was then immediately written off as a deemed dividend as the Series B Preferred Stock does not have a stated redemption date and is immediately convertible at the option of the holder. The Company has computed diluted net loss per common share after giving consideration to all potentially dilutive common shares, including convertible preferred stock and options to purchase common stock during the period determined using the if-converted method, except where the effect of including such securities would be antidilutive. Because the Company has reported net losses since inception, these potential common shares have been anti-dilutive and basic and diluted loss per share have been the same. The Company excluded the following potential common shares from the computation of diluted net loss per share attributable to common stockholders for the years ended December 31, 2020 and 2019 because including them would have had an anti-dilutive effect : Year Ended December 31, 2020 2019 Series Seed Preferred Stock — 430,693 Series A Preferred Stock — 5,000,623 Series B Preferred Stock — 4,178,645 Options to purchase common stock 1,935,632 1,863,117 Shares reserved for future issuance under the ESPP 191,363 —

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Related Party Transactions	14. Related Party Transactions Lundbeck Lundbeckfond Invest A/S is one of the Company’s stockholders and participated in all tranches of the Series A preferred stock financing and both tranches of the Series B preferred stock financing. Prior to the conversion of the Company’s preferred stock, Lundbeckfond Invest A/S owned 5,470,492 shares of Series A Preferred Stock as of December 31, 2019, and 478,749 shares of Series Seed Preferred Stock as of December 31, 2019. Lundbeckfond Invest A/S owned 1,326,111 shares of Series B Preferred Stock as of December 31, 2019. All shares of Preferred Stock converted into shares of common stock upon closing of the IPO. Lundbeckfond Invest A/S also purchased 187,500 shares of common stock in the IPO. This reflects a 7.4% and a 9.3% ownership interest on a fully diluted basis as of December 31, 2020 and 2019, respectively. Mette Kirstine Agger, a member of the Company’s board of directors, is a Managing Partner at Lundbeckfonden Ventures, which is an affiliate of Lundbeckfond Invest A/S. Lundbeck, an affiliate of Lundbeckfond Invest A/S, is also one of the Company’s stockholders and participated in the fourth tranche of the Company’s Series A Preferred Stock financing. Prior to the conversion of the Company’s Preferred Stock, Lundbeck owned 499,069 shares of Series A Preferred Stock as of December 31, 2019, as well as 443,271 shares of common stock issued in conjunction with the Lundbeck Agreement (See Note 7). All shares of Preferred Stock converted into shares of common stock upon closing of the IPO. This reflects a 2.7% and a 4.2% ownership interest on a fully diluted basis as of December 31, 2020 and 2019, respectively. Lundbeck did not participate in the Series B Preferred Stock financing. To date, pursuant to the Lundbeck Agreement, the Company has made cash payments to Lundbeck of $1.8 million consisting of an upfront payment and ongoing milestone payments which are recorded as research and development expense . Cydan Development, Inc. In January 2016, the Company entered into a Business Services Agreement with Cydan Development, Inc., or Cydan, pursuant to which Cydan provided office space, personnel assistance, and other business services to the Company on an as-needed basis. At the time the agreement was signed, Cydan was considered a related party because Cydan was a holder of more than 5% of the Company’s capital stock and Dr. James McArthur was the Company’s founder, President and Chief Executive Officer, a member of the Company’s board of directors and a holder of more than 5% of the Company’s capital stock and the Chief Scientific Officer of Cydan. As of June 30, 2020, Cydan was no longer considered a related party. The Company paid Cydan less than $0.3 million during the year ended December 31, 2019 related to the Business Services Agreement, all of which was recorded as research and development expense. The Company agreed with Cydan to terminate the Business Services Agreement and all related services rendered by Cydan to the Company effective as of August 17, 2019. Accordingly, there were no amounts due to Cydan as of December 31, 2020 and 2019, respectively

Benefit Plans

Benefit Plans	12 Months Ended
	Dec. 31, 2020
Compensation And Retirement Disclosure [Abstract]
Benefit Plans	15. Benefit Plans The Company established a defined contribution savings plan under Section 401(k) of the Internal Revenue Code effective as of January 2019. This plan covers substantially all employees who meet minimum age and service requirements and allows participants to defer a portion of their annual compensation on a pre-tax basis. Matching contributions to the plan may be made at the discretion of the Board. The Company contributed a match of $0.1 million to the 401(k) plan during the year ended December 31, 2020. The Company did not make any contributions to the plan in 2019.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Basis of presentation	Basis of presentation The accompanying consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ASC”) and as amended by Accounting Standards Updates of the Financial Accounting Standards Board (“FASB”).
Principles of Consolidation	Principles of Consolidation The accompanying consolidated financial statements of the Company include the accounts of its wholly owned subsidiaries, IMARA Security Corporation and IMARA E.U. Limited. All intercompany transactions and balances have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of expenses during the reporting periods. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, accrued research and development expenses, stock-based compensation expense, the fair value of the common stock and Preferred Stock and income taxes. Actual results could differ materially from those estimates.
Segments	Segments Operating segments are defined as components of an enterprise for which separate and discrete information is available for evaluation by the chief operating decision-maker in deciding how to allocate resources and assess performance. The Company has one operating segment. The Company’s chief operating decision maker, its Chief Executive Officer, manages the Company’s operations on a consolidated basis for the purpose of allocating resources. All of the Company’s long-lived assets are held in the United States.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments that are readily convertible into cash with original maturities of three months or less from the date of purchase to be cash equivalents. Cash and cash equivalents include cash held in banks and amounts held in money market funds. Cash equivalents are stated at cost, which approximates market value.
Restricted Cash	Restricted Cash Restricted cash of less than $0.1 million as of December 31, 2020 and December 31, 2019, represents a letter of credit held as collateral in support of the Company’s facility lease. Restricted cash is included as a component of other assets on the Company’s consolidated balance sheets.
Investments	Investments The Company’s investments are maintained by investment managers and consist of corporate debt securities and commercial paper with original maturities of over 90 days, all of which are considered available-for-sale securities. The Company classifies its available-for-sale securities as short-term investments on the consolidated balance sheets, even though the stated maturity date may be one year or more beyond the current balance sheet date, as the Company views those securities as available for use in current operations, if needed. Available-for-sale securities are carried at fair value with their unrealized gains and losses included in accumulated other comprehensive income within stockholders’ equity (deficit), until such gains and losses are realized in other income (expense) within the consolidated statements of operations and comprehensive loss or until an unrealized loss is considered other-than-temporary. The Company evaluates its investments with unrealized losses for other-than-temporary impairment. When assessing investments for other-than-temporary declines in value, the Company considers such factors as, among other things, how significant the decline in value is as a percentage of the original cost, how long the market value of the investment has been less than its original cost, the Company’s ability and intent to retain the investment for a period of time sufficient to allow for any anticipated recovery in fair value and market conditions. If the Company determines from this analysis that it does not expect to receive cash flows sufficient to recover the entire amortized cost of the security, a credit loss exists, the impairment is considered other-than-temporary and is recognized in the consolidated statements of operations and comprehensive loss.
Deferred Offering Costs	Deferred Offering Costs The Company capitalizes certain legal, professional, accounting and other third-party fees that are directly associated with in-process equity issuances as deferred offering costs until such equity issuances are consummated. After consummation of the equity issuance, these costs are recorded as a reduction in the capitalized amount associated with the equity issuance. Should the equity issuance be abandoned, the deferred offering costs will be expensed immediately as a charge to operating expenses in the consolidated statement of operations and comprehensive loss. On March 16, 2020, the Company completed its IPO; accordingly, the Company recognized the deferred offering costs of approximately $3.9 million as a reduction from gross proceeds associated with the IPO through additional paid-in capital in the accompanying consolidated balance sheet. Deferred offering costs classified in other assets on the accompanying consolidated balance sheet as of December 31, 2019 were $2.1 million. There were no deferred offering costs as of December 31, 2020.
Concentrations of Credit Risk and Off-Balance Sheet Risk	Concentrations of Credit Risk and Off-Balance Sheet Risk Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash, cash equivalents and investments. Periodically, the Company maintains deposits in accredited financial institutions in excess of federally insured limits. The Company deposits its cash in financial institutions that it believes have high credit quality and have not experienced any losses on such accounts and does not believe it is exposed to any unusual credit risk beyond the normal credit risk associated with commercial banking relationships. Such deposits have and will continue to exceed federally insured limits. The Company has not experienced any losses on its cash deposits. The Company’s available-for-sale investments primarily consist of high-grade corporate debt and commercial paper, and potentially subject the Company to concentrations of credit risk. The Company has adopted an investment policy that limits the amounts the Company may invest in any one type of investment and requires all investments held by the Company to be highly rated, thereby reducing credit risk exposure. As of December 31, 2020 and 2019, the Company had no off-balance sheet risk such as foreign exchange contracts, option contracts, or other hedging arrangements.
Comprehensive Loss	Comprehensive Loss Comprehensive loss includes net loss and certain changes in stockholders’ equity (deficit) that are excluded from net loss. For the years ended December 31, 2020 and 2019, as a result of the Company’s investments in available-for-sale securities, the Company’s comprehensive loss includes unrealized gains and losses on those available-for-sale securities.
Fair Value Measurements	Fair Value Measurements Certain assets and liabilities of the Company are carried at fair value under GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. • Level 3—Unobservable inputs that are supported by little or no market activity that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. An entity may choose to measure many financial instruments and certain other items at fair value at specified election dates. Subsequent unrealized gains and losses on items for which the fair value option has been elected will be reported in earnings. The carrying amounts reflected in the consolidated balance sheets for prepaid expenses and other current assets, accounts payable and accrued expenses approximate their fair values due to their short-term nature of these assets and liabilities.
Property and Equipment, Net	Property and Equipment, Net Property and equipment is stated at cost, net of accumulated depreciation. Depreciation is calculated using the straight-line method over the estimated useful lives of the assets, which are as follows: Estimated Useful Life Computer equipment and software 3 years Furniture and fixtures 5 years Laboratory equipment 5 years Leasehold improvements Shorter of useful life or remaining lease term Purchased assets that are not yet in service are recorded to construction-in-process and no depreciation expense is recorded. Once they are placed in service they are reclassified to the appropriate asset class. Upon the retirement or sale of an asset, the related cost and accumulated depreciation is removed from the accounts and any resulting gain or loss is recorded to other income (expense), net. Expenditures for maintenance and repairs are expensed as incurred.
Deferred Rent	Deferred Rent Deferred rent consists of rent escalation payment terms, tenant improvement allowances and other incentives received from landlords related to the Company’s operating leases. Rent escalation represents the difference between actual operating lease payments due and straight-line rent expense, which is recorded by the Company over the term of the lease. Tenant improvement allowances and other incentives are recorded as deferred rent and amortized as a reduction of periodic rent expense, over the term of the applicable lease.
Research and Development Expense	Research and Development Expenses Research and development costs are expensed as incurred. Research and development expenses consist of costs incurred in performing research and development activities, including salaries, stock-based compensation and benefits, facilities costs, depreciation, third-party license fees, and external costs of outside vendors engaged to conduct preclinical development activities and clinical trials as well as to manufacture research and development materials. Non-refundable prepayments for goods or services that will be used or rendered for future research and development activities are deferred and capitalized. Such amounts are expensed as the goods are delivered or the related services are performed or until it is no longer expected that the goods will be delivered, or the services rendered. Costs incurred in obtaining technology licenses are recognized as research and development expense as incurred if the technology licensed has not reached technological feasibility and has no alternative future uses.
Accrued Research and Development Expenses	Accrued Research and Development Expenses The Company has entered into various research and development related contracts with parties both inside and outside of the United States, including contracts with third-party contract research organizations and contract manufacturing organizations. These agreements are cancelable, and related payments are recognized as research and development expenses as incurred. The Company records accrued liabilities for estimated ongoing research costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes the progress of the studies or clinical trials, including the phase or completion of events, invoices received and contracted costs. Significant judgments and estimates are made in determining the accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates. To date, the Company’s historical accrual estimates have not been materially different from the actual costs.
Patents Costs	Patent Costs All patent-related costs incurred in connection with filing and prosecuting patent applications are expensed as incurred due to the uncertainty about the recovery of the expenditure and are classified as general and administrative expenses.
Stock-Based Compensation	Stock-Based Compensation The Company accounts for all stock-based awards granted to employees and non-employees as stock-based compensation expense at fair value. For stock-based awards issued to employees and members of the Company’s board of directors (the “Board”) for their services as a member of the Board, the Company measures the estimated fair value of the stock-based award on the date of grant. Since the Company’s initial public offering in March 2020, the fair value of the common stock has been determined based on the closing price of the Company’s stock on the date of grant. Prior to the Company’s initial public offering, the Company determined the fair value of the underlying common stock based on input from management and approved by the Board, which utilized the valuation of the Company’s enterprise value determined utilizing various methods including the back-solve method, the option-pricing method (“OPM”) or a hybrid of the probability-weighted expected return method (“PWERM”) and the OPM. The total enterprise value was then allocated to the various outstanding equity instruments, including the underlying common stock, utilizing the option-pricing model. For employee and non-employee awards, the Company recognizes compensation expense over the requisite service period, which is generally the vesting period of the respective award based on the grant date fair value of the award. For awards that include performance-based vesting conditions expense is recognized using the accelerated attribution method when the performance condition is deemed to be probable. The Company accounts for forfeitures as they occur. The Company determines the fair value of restricted stock awards in reference to the fair value of its common stock less any applicable purchase price. The fair value of each stock option grant is estimated on the date of grant using the Black-Scholes option-pricing model, which requires inputs based on certain subjective assumptions, including the expected stock price volatility, the expected term of the option, the risk-free interest rate for a period that approximates the expected term of the option and the Company’s expected dividend yield. The fair value of each restricted stock award is determined on the date of grant based on the fair value of the Company’s common stock on that same date. Given the Company’s limited trading history as a public company, the Company determines the volatility for awards granted based on an analysis of reported data for a group of guideline companies that issued options with substantially similar terms. The expected volatility has been determined using a weighted-average of the historical volatility measures of this group of guideline companies. The Company expects to continue to do so until such time as it has adequate historical data regarding the volatility of its own traded stock price. The expected term of the Company’s stock options granted to employees has been determined utilizing the “simplified” method for awards that qualify as “plain-vanilla” options. Under the simplified method, the expected term is presumed to be the midpoint between the vesting date and the end of the contractual term. The Company utilizes this method due to lack of historical exercise data and the plain nature of its stock-based awards. Prior to the Company’s IPO, the expected term of stock options granted to non-employees also used the “simplified” method. Following the Company’s IPO, the expected term of options granted to non-employees is determined by contractual term. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. The Company has not paid, and does not anticipate paying, cash dividends on its common stock; therefore, the expected dividend yield is assumed to be zero. The Company classifies stock-based compensation expense in its consolidated statements of operations and comprehensive loss in the same manner in which the award recipient’s cash compensation costs are classified.
Income Taxes	Income Taxes The Company accounts for income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in the financial statements or the Company’s tax returns. Under this method, deferred tax assets and liabilities are determined based on the differences between the consolidated financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Changes in deferred tax assets and liabilities are recorded in the provision for income taxes. The Company assesses the likelihood that its deferred tax assets will be recovered from future taxable income and, to the extent it believes, based upon the weight of available evidence, that it is more likely than not that all or a portion of the deferred tax assets will not be realized, a valuation allowance is established. The Company accounts for uncertain tax positions recognized in the consolidated financial statements by prescribing a more-likely-than-not threshold for financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. The provision for income taxes includes the effects of any resulting tax reserves, or unrecognized tax benefits, that are considered appropriate as well as the related net interest and penalties.
Net Loss per Share	Net Loss per Share Basic net loss per share is computed by dividing net loss by the weighted-average number of common shares outstanding during the period. Diluted net loss per share is computed using the weighted-average number of common shares outstanding during the period and, if dilutive, the weighted-average number of potential shares of common stock. Net loss per share attributable to common stockholders is calculated using the two-class method, which is an earnings allocation formula that determines net loss per share for the holders of the Company’s common shares and participating securities. The Company’s Preferred Stock contained participation rights in any dividend paid by the Company and is deemed to be a participating security. Net loss attributable to common stockholders and participating preferred shares are allocated to each share on an as-converted basis as if all of the earnings for the period had been distributed. The participating securities do not include a contractual obligation to share in losses of the Company and are not included in the calculation of net loss per share in the periods in which a net loss is recorded. Diluted net loss per share is computed using the more dilutive of (a) the two-class method or (b) the if-converted method. The Company allocates earnings first to preferred stockholders based on dividend rights and then to common and preferred stockholders based on ownership interests. The weighted-average number of common shares included in the computation of diluted net loss effect to all potentially dilutive common equivalent shares, including outstanding stock options and Preferred Stock. Common stock equivalent shares are excluded from the computation of diluted net loss per share if their effect is antidilutive. In periods in which the Company reports a net loss attributable to common stockholders, diluted net loss per share attributable to common stockholders is generally the same as basic net loss per share attributable to common stockholders since dilutive common shares are not assumed to have been issued if their effect is anti-dilutive.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842), which, among other things, requires lessees to recognize an obligation to make lease payments arising from a lease, measured on a discounted basis, and a right-of-use asset, which is an asset that represents the lessee's right to use, or control the use of, a specified asset for the lease term. Expenses are recognized in the consolidated statement of operations in a manner similar to current accounting guidance. The Company expects to make an accounting policy election to not recognize an asset and liability for leases with a term of twelve months or less. The standard is effective for fiscal years beginning after December 15, 2021. The Company will early adopt the accounting standard effective January 1, 2021 using a modified retrospective approach, which applies the provisions of the new guidance at the effective date without adjusting the comparative periods presented. The Company is finalizing its evaluation of the impacts that the adoption of this accounting guidance will have on the consolidated financial statements and estimates approximately $1 million of right-to-use assets and lease liabilities will be recognized in the balance sheet upon adoption. In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments In July 2017, the FASB issued ASU 2017-11, Earnings Per Share (Topic 260), Distinguishing Liabilities from Equity (Topic 480), Derivatives and Hedging (Topic 815) I. Accounting for Certain Financial Instruments with Down Round Features II. Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with a Scope Exception . On August 5, 2020, the FASB issued ASU 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Schedule of Estimated Useful Lives of Assets	Property and equipment is stated at cost, net of accumulated depreciation. Depreciation is calculated using the straight-line method over the estimated useful lives of the assets, which are as follows: Estimated Useful Life Computer equipment and software 3 years Furniture and fixtures 5 years Laboratory equipment 5 years Leasehold improvements Shorter of useful life or remaining lease term

Fair Value of Financial Asset_2

Fair Value of Financial Assets and Liabilities (Tables)	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis	The following table presents information about the Company’s financial assets and liabilities measured at fair value on a recurring basis and indicates the level of the fair value hierarchy utilized to determine such fair values (in thousands): December 31, 2020 Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Other Observable Inputs Description Total (Level 1) (Level 2) (Level 3) Assets: Money market funds, included in cash and cash equivalents $ 41,208 $ 41,208 $ — $ — Marketable securities: Corporate debt securities 14,807 — 14,807 — Commercial paper 25,717 — 25,717 — Total financial assets $ 81,732 $ 41,208 $ 40,524 $ — December 31, 2019 Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Other Observable Inputs Description Total (Level 1) (Level 2) (Level 3) Assets: Money market funds, included in cash and cash equivalents $ 4,477 $ 4,477 $ — $ — Marketable securities: Corporate debt securities 5,772 — 5,772 — Commercial paper 18,199 — 18,199 — Total financial assets $ 28,448 $ 4,477 $ 23,971 $ —

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2020
Investments Debt And Equity Securities [Abstract]
Summary of Investments	The following table summarizes the Company’s investments as of December 31, 2020 and 2019 (in thousands): December 31, 2020 Amortized Cost Gross Unrealized Gains Gross Unrealized Loss Fair Value Current: Commercial paper $ 25,716 $ 1 $ — $ 25,717 Corporate debt securities 14,804 3 — 14,807 Total $ 40,520 $ 4 $ — $ 40,524 December 31, 2019 Amortized Cost Gross Unrealized Gains Gross Unrealized Loss Fair Value Current: Commercial paper $ 18,167 $ 32 $ — $ 18,199 Corporate debt securities 5,772 — — 5,772 Total $ 23,939 $ 32 $ — $ 23,971

Property and Equipment, net (T

Property and Equipment, net (Tables)	12 Months Ended
	Dec. 31, 2020
Property Plant And Equipment [Abstract]
Summary of Property and Equipment, net	Property and equipment, net consisted of the following (in thousands): December 31, 2020 December 31, 2019 Property and equipment: Leasehold improvements $ 336 $ 339 Furniture and fixtures 143 136 Property and equipment $ 479 $ 475 Less: accumulated depreciation (130 ) (33 ) Property and equipment, net $ 349 $ 442

Accrued Expenses (Tables)

Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2020
Payables And Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses consisted of the following (in thousands): December 31, 2020 December 31, 2019 Accrued research and development expenses $ 2,732 $ 1,106 Accrued compensation and benefits 1,090 802 Accrued professional services 355 330 Accrued other 99 302 Total accrued expenses $ 4,276 $ 2,540

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Summary of Future Minimum Lease Payments	The following table summarizes the future minimum lease payments due under the Company’s operating leases as of December 31, 2020 exclusive of amounts prepaid by the Company (in thousands): December 31, 2020 2021 273 2022 278 2023 284 2024 229 $ 1,064

Convertible Preferred Stock (Ta

Convertible Preferred Stock (Tables)	12 Months Ended
	Dec. 31, 2020
Temporary Equity Disclosure [Abstract]
Schedule of Convertible Preferred Stock	As of December 31, 2019, convertible preferred stock consisted of the following (in thousands, except share data): December 31, 2019 Preferred Stock Authorized Preferred Stock Issued and Outstanding Carrying Value Liquidation Value Common stock Issuable Upon Conversion Series Seed Preferred Stock 2,712,960 2,712,960 $ 1,460 $ 2,713 430,693 Series A Preferred Stock 31,499,040 31,499,040 30,729 31,499 5,000,623 Series B Preferred Stock 36,166,661 26,321,313 45,575 45,849 4,178,645 70,378,661 60,533,313 $ 77,764 $ 80,061 9,609,961

Stockholders' Equity (Deficit)

Stockholders' Equity (Deficit) (Tables)	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Schedule of Shares Reserved for Future Issuance	As of December 31, 2020 and December 31, 2019, the Company has reserved for future issuance the following shares of common stock: December 31, 2020 December 31, 2019 Conversion of outstanding preferred stock — 9,609,961 Shares reserved for future issuance under the 2016 Stock Incentive Plan — 228,852 Shares reserved for future issuance under the 2020 Equity Incentive Plan 1,110,675 — Shares reserved for future issuance under the 2020 Employee Stock Purchase Plan 191,363 — 1,302,038 9,838,813

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2020
Compensation Related Costs [Abstract]
Summary of Stock Option Activity	The following table summarizes the Company’s stock option activity: Number of Shares Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (in years) Aggregate Intrinsic Value (in thousands) Outstanding as of December 31, 2019 1,863,117 $ 4.60 8.90 $ 15,151 Granted 759,139 19.80 Exercised (265,945 ) 4.34 Forfeited (420,679 ) 8.02 Outstanding as of December 31, 2020 1,935,632 $ 9.85 8.14 $ 24,260 Options vested and exercisable as of December 31, 2020 602,986 $ 4.34 6.42 $ 10,678
Summary of Stock-Based Compensation Fair Value Assumptions	The assumptions that the Company used to determine the grant date fair value of stock options granted to employees, non-employees and members of the Board during the years ended December 31, 2020 and 2019 were as follows, presented on a weighted-average basis : Year Ended December 31, 2020 2019 Expected term (in years) 6.17 6.11 Expected volatility 74.7 % 69.3 % Expected dividend yield 0.00 % 0.00 % Risk-free interest rate 0.52 % 2.18 %
Summary of Stock-Based Compensation Expense	Stock-based compensation expense included in the Company’s consolidated statements of operations and comprehensive loss is as follows (in thousands): Year Ended December 31, 2020 2019 Research and development $ 1,490 $ 301 General and administrative 741 598 Total stock-based compensation expense $ 2,231 $ 899

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Schedule of Reconciliation of Income Tax Expense (Benefit)	A reconciliation of income tax expense (benefit) computed at the statutory federal income tax rate to income taxes as reflected in the consolidated financial statements is as follows: 2020 2019 Income taxes at U.S. statutory rate 21 % 21 % State income taxes 6 6 Tax Credit 7 3 Other 2 (1 ) Change in valuation allowance (36 ) (29 ) Total provision for income taxes 0 % 0 %
Schedule of Components of Deferred Tax Assets and Liabilities	The significant components of the Company’s deferred tax assets and liabilities as of December 31, 2020 and 2019 are comprised of the following (in thousands): Year Ended December 31, 2020 2019 Deferred tax assets Net operating loss carryforwards $ 24,657 $ 13,284 Tax credits carryforwards 3,948 1,020 Stock-based compensation 686 246 Amortization 545 611 Accruals 272 200 Lease incentive liability 17 21 Other 42 31 Total deferred tax assets 30,167 15,413 Valuation allowance (30,149 ) (15,385 ) Net deferred tax assets 18 28 Deferred tax liabilities Tenant improvement allowance (17 ) (21 ) Unrealized gains/losses on investments (1 ) (7 ) Total deferred tax liabilities (18 ) (28 ) Net deferred taxes $ — $ —

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Computation of Basic and Diluted Net Loss Per Share	The following table sets forth the computation of the Company’s basic and diluted net loss per share for the years ended December 31, 2020 and 2019 (in thousands, except share and per share amounts): Year Ended December 31, 2020 2019 Numerator: Net loss attributable to common stockholders—basic and diluted $ (49,218 ) $ (23,463 ) Denominator: Weighted-average number of common shares used in net loss per share—basic and diluted 13,924,730 702,455 Net loss per share—basic and diluted $ (3.53 ) $ (33.40 )
Anti Dilutive Potential Common Shares Excluded From Computation of Diluted Net Loss Per Share	The Company excluded the following potential common shares from the computation of diluted net loss per share attributable to common stockholders for the years ended December 31, 2020 and 2019 because including them would have had an anti-dilutive effect : Year Ended December 31, 2020 2019 Series Seed Preferred Stock — 430,693 Series A Preferred Stock — 5,000,623 Series B Preferred Stock — 4,178,645 Options to purchase common stock 1,935,632 1,863,117 Shares reserved for future issuance under the ESPP 191,363 —

Nature of the Business - Additi

Nature of the Business - Additional Information (Details) $ / shares in Units, $ in Thousands	Apr. 13, 2020USD ($)shares	Mar. 16, 2020USD ($)$ / sharesshares	Feb. 25, 2020USD ($)$ / sharesshares	Feb. 29, 2020	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)shares	May 31, 2019$ / shares	Mar. 31, 2019$ / sharesshares
Nature Of Business [Line Items]
Reverse stock split					1-for-6.299
Reverse stock splits, conversion ratio				0.159
Convertible preferred stock, shares issued | shares						60,533,313
Stock issuance costs					$ 1,718	$ 1,996
Proceeds from initial public offering, net of underwriting discounts, commissions and offering costs		$ 75,200			80,427
Aggregate gross proceeds of common stock issued and sold	$ 11,300
Underwriting discounts and commissions and offering expenses					10,000
Conversion of outstanding preferred stock | shares		70,378,661
Common stock issued upon conversion | shares		11,172,955				9,609,961
Cash, cash equivalents, and investments					88,200
Accumulated deficit					96,113	$ 54,753
IPO
Nature Of Business [Line Items]
Preferred stock, per share | $ / shares		$ 16
Common stock issued and sold | shares	705,000	4,700,000
Net proceeds after deducting underwriting discounts and commissions and offering expenses					$ 76,500
Conversion of outstanding preferred stock | shares		70,378,661
Series B Preferred Stock
Nature Of Business [Line Items]
Convertible preferred stock, shares issued | shares						26,321,313		25,316,663
Preferred stock, per share | $ / shares							$ 1.7419	$ 1.7419
Common stock issued upon conversion | shares						4,178,645
Series B Preferred Stock | Second Tranche
Nature Of Business [Line Items]
Convertible preferred stock, shares issued | shares			1,562,994
Preferred stock, per share | $ / shares			$ 10.9722
Proceeds from issuance of convertible preferred stock, net of issuance costs			$ 17,100
Series B Preferred Stock | Second Tranche | Maximum
Nature Of Business [Line Items]
Stock issuance costs			$ 100

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details)	12 Months Ended
	Dec. 31, 2020USD ($)Segment	Dec. 31, 2019USD ($)	Jan. 01, 2021USD ($)	Mar. 16, 2020USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of operating segments | Segment	1
Restricted cash	$ 88,000	$ 88,000
Deferred offering costs	0	2,100,000
Off-balance sheet risk	0	0
Depreciation expense	$ 97,000	33,000
ASU 2016-02
Summary Of Significant Accounting Policies [Line Items]
Operating Lease, liability			$ 1,000,000
Operating lease, right-of-Use assets			$ 1,000,000
Change in accounting principle, accounting standards Update Early adoption [true false]	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2021
Change in accounting principle, accounting standards update, immaterial effect [true false]	false
Construction-in-process
Summary Of Significant Accounting Policies [Line Items]
Depreciation expense	$ 0
Initial Public Offering
Summary Of Significant Accounting Policies [Line Items]
Deferred offering costs				$ 3,900,000
Maximum
Summary Of Significant Accounting Policies [Line Items]
Restricted cash	$ 100,000	100,000
Depreciation expense		$ 100,000

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Estimated Useful Lives of Assets (Details)	12 Months Ended
	Dec. 31, 2020
Computer Equipment and Software
Property Plant And Equipment [Line Items]
Estimated Useful Life	3 years
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Estimated Useful Life	5 years
Laboratory Equipment
Property Plant And Equipment [Line Items]
Estimated Useful Life	5 years
Leasehold Improvements
Property Plant And Equipment [Line Items]
Estimated Useful Life	Shorter of useful life or remaining lease term

Fair Value of Financial Asset_3

Fair Value of Financial Assets and Liabilities - Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Assets:
Marketable securities	$ 40,524	$ 23,971
Fair Value Measurements Recurring
Assets:
Total financial assets	81,732	28,448
Fair Value Measurements Recurring | Money Market Funds
Assets:
Cash and cash equivalents	41,208	4,477
Fair Value Measurements Recurring | Corporate Debt Securities
Assets:
Marketable securities	14,807	5,772
Fair Value Measurements Recurring | Commercial Paper
Assets:
Marketable securities	25,717	18,199
Fair Value Measurements Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Total financial assets	41,208	4,477
Fair Value Measurements Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Money Market Funds
Assets:
Cash and cash equivalents	41,208	4,477
Fair Value Measurements Recurring | Significant Other Observable Inputs (Level 2)
Assets:
Total financial assets	40,524	23,971
Fair Value Measurements Recurring | Significant Other Observable Inputs (Level 2) | Corporate Debt Securities
Assets:
Marketable securities	14,807	5,772
Fair Value Measurements Recurring | Significant Other Observable Inputs (Level 2) | Commercial Paper
Assets:
Marketable securities	$ 25,717	$ 18,199

Fair Value of Financial Asset_4

Fair Value of Financial Assets and Liabilities - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Fair value, assets, Level 1 to Level 2 transfers, amount	$ 0	$ 0
Fair value, assets, Level 2 to Level 1 transfers, amount	0	0
Fair value, asset transfers Into Level 3	0	0
Fair value, asset, transfers out of Level 3	$ 0	$ 0

Investments - Summary of Invest

Investments - Summary of Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 40,520	$ 23,939
Gross Unrealized Gains	4	32
Fair Value	40,524	23,971
Commercial Paper
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	25,716	18,167
Gross Unrealized Gains	1	32
Fair Value	25,717	18,199
Corporate Debt Securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	14,804	5,772
Gross Unrealized Gains	3
Fair Value	$ 14,807	$ 5,772

Investments - Additional Inform

Investments - Additional Information (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Investments Debt And Equity Securities [Abstract]
Available-for-sale securities in unrealized loss positions	$ 0	$ 0

Property and Equipment, net - S

Property and Equipment, net - Summary of Property and Equipment, net (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property Plant And Equipment [Line Items]
Property and equipment	$ 479	$ 475
Less: accumulated depreciation	(130)	(33)
Property and equipment, net	349	442
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment	336	339
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property and equipment	$ 143	$ 136

Property and Equipment, net - A

Property and Equipment, net - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property Plant And Equipment [Line Items]
Depreciation expense	$ 97,000	$ 33,000
Maximum
Property Plant And Equipment [Line Items]
Depreciation expense		$ 100,000

Accrued Expenses - Schedule of

Accrued Expenses - Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Payables And Accruals [Abstract]
Accrued research and development expenses	$ 2,732	$ 1,106
Accrued compensation and benefits	1,090	802
Accrued professional services	355	330
Accrued other	99	302
Total accrued expenses	$ 4,276	$ 2,540

License Agreements - Additional

License Agreements - Additional Information (Details) - USD ($)	1 Months Ended	12 Months Ended	57 Months Ended
	Apr. 30, 2016	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
License Agreements [Line Items]
Common stock, shares issued		17,548,263	17,548,263	702,510
Lundbeck | Lundbeck Agreement
License Agreements [Line Items]
Maximum development milestones payments due	$ 23,500,000
Maximum development milestones payments due for other than licensed product	$ 11,800,000
Upfront and ongoing milestone payments		$ 0
Common stock, shares issued	167,523			443,271
Outstanding equity percentage pursuant to restricted stock agreement	8.00%
Notice period for agreement termination		180 days
Lundbeck | Lundbeck Agreement | Research and Development Expense
License Agreements [Line Items]
Upfront and ongoing milestone payments			$ 1,800,000

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	May 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Rent expense		$ 0.2	$ 0.2
Operating lease description		In May 2019, the Company entered into a new operating lease agreement for office space totaling 4,210 square feet, located in Boston, Massachusetts with a 62-month term.
Operating lease term of contract	62 months
Operating lease, payments	$ 0.3
Security deposit			$ 0.1

Commitments and Contingencies_2

Commitments and Contingencies - Summary of Future Minimum Lease Payments (Details) $ in Thousands	Dec. 31, 2020USD ($)
Lessee Disclosure [Abstract]
2021	$ 273
2022	278
2023	284
2024	229
Total	$ 1,064

Convertible Preferred Stock - A

Convertible Preferred Stock - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	Mar. 16, 2020	Feb. 25, 2020	May 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Temporary Equity [Line Items]
Preferred stock authorized					70,378,661
Convertible preferred stock, par value					$ 0.001
Preferred shares, issued					60,533,313
Conversion of outstanding preferred stock	70,378,661
Common stock issued upon conversion	11,172,955				9,609,961
IPO
Temporary Equity [Line Items]
Stock value, per share	$ 16
Conversion of outstanding preferred stock	70,378,661
IPO | Common Stock
Temporary Equity [Line Items]
Stock value, per share	$ 16
Common stock issued upon conversion	11,172,955
Underwritten Public Offering | Second A&R COI
Temporary Equity [Line Items]
Proceeds of gross offering				$ 60
Underwritten Public Offering | Second A&R COI | Minimum [Member]
Temporary Equity [Line Items]
Stock value, per share				$ 2.6129
Series B Preferred Stock
Temporary Equity [Line Items]
Preferred stock authorized					36,166,661
Preferred shares, issued					26,321,313	25,316,663
Stock value, per share			$ 1.7419			$ 1.7419
Obligation for additional shares to be issued						10,849,998
Additional number of shares issued			1,004,650
Common stock issued upon conversion					4,178,645
Liquidation preferred stock, per share				1.7419
Series B Preferred Stock | Second Tranche
Temporary Equity [Line Items]
Preferred shares, issued		1,562,994
Stock value, per share		$ 10.9722
Net proceeds from sale		$ 17.1
Intrinsic value of beneficial conversion discount		$ 7.9
Series A Preferred Stock
Temporary Equity [Line Items]
Preferred stock authorized					31,499,040
Preferred shares, issued					31,499,040
Common stock issued upon conversion					5,000,623
Liquidation preferred stock, per share				1
Series Seed Preferred Stock
Temporary Equity [Line Items]
Preferred stock authorized					2,712,960
Preferred shares, issued					2,712,960
Common stock issued upon conversion					430,693
Liquidation preferred stock, per share				$ 1

Convertible Preferred Stock - S

Convertible Preferred Stock - Schedule of Convertible Preferred Stock (Details) - USD ($) $ in Thousands	Mar. 16, 2020	Dec. 31, 2019	Mar. 31, 2019
Temporary Equity [Line Items]
Preferred Stock Authorized		70,378,661
Preferred Stock Issued		60,533,313
Preferred Stock Outstanding		60,533,313
Carrying Value		$ 77,764
Liquidation Value		$ 80,061
Common stock Issuable Upon Conversion	11,172,955	9,609,961
Series Seed Preferred Stock
Temporary Equity [Line Items]
Preferred Stock Authorized		2,712,960
Preferred Stock Issued		2,712,960
Preferred Stock Outstanding		2,712,960
Carrying Value		$ 1,460
Liquidation Value		$ 2,713
Common stock Issuable Upon Conversion		430,693
Series A Preferred Stock
Temporary Equity [Line Items]
Preferred Stock Authorized		31,499,040
Preferred Stock Issued		31,499,040
Preferred Stock Outstanding		31,499,040
Carrying Value		$ 30,729
Liquidation Value		$ 31,499
Common stock Issuable Upon Conversion		5,000,623
Series B Preferred Stock
Temporary Equity [Line Items]
Preferred Stock Authorized		36,166,661
Preferred Stock Issued		26,321,313	25,316,663
Preferred Stock Outstanding		26,321,313
Carrying Value		$ 45,575
Liquidation Value		$ 45,849
Common stock Issuable Upon Conversion		4,178,645

Stockholders' Equity (Deficit_2

Stockholders' Equity (Deficit) - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Mar. 16, 2020	Dec. 31, 2019
Equity [Abstract]
Preferred stock, shares authorized	10,000,000	10,000,000	0
Preferred stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	200,000,000	200,000,000	100,000,000
Common stock, par value	$ 0.001	$ 0.001	$ 0.001
Cash dividends	$ 0
Preferred stock, shares issued	0		0
Preferred stock, shares outstanding	0		0

Stockholders' Equity (Deficit_3

Stockholders' Equity (Deficit) - Schedule of Shares Reserved for Future Issuance (Details) - shares	Dec. 31, 2020	Mar. 11, 2020	Dec. 31, 2019
Class Of Stock [Line Items]
Shares reserved for future issuance	1,302,038		9,838,813
Conversion of Outstanding Preferred Stock
Class Of Stock [Line Items]
Shares reserved for future issuance			9,609,961
2016 Stock Incentive Plan
Class Of Stock [Line Items]
Shares reserved for future issuance	0	228,852	228,852
2020 Equity Incentive Plan
Class Of Stock [Line Items]
Shares reserved for future issuance	1,110,675
2020 Employee Stock Purchase Plan
Class Of Stock [Line Items]
Shares reserved for future issuance	191,363

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($)	Mar. 11, 2020	Jun. 21, 2019	Jun. 05, 2019	May 16, 2019	Dec. 31, 2020	Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares remaining available for future issuance					1,302,038	9,838,813
Share-based compensation award, weighted-average fair value					$ 12.95	$ 3.46
Share-based compensation award, granted					759,139
Stock-based compensation expense					$ 2,231,000	$ 899,000
Unrecognized stock-based compensation expense					$ 9,500,000
Expected weighted average period to recognize expense					3 years 2 months 19 days
Performance Based Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation award, granted		220,928	220,928	220,928
Stock-based compensation expense					$ 300,000
Performance Based Awards | Tranche One
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option vest percentage					25.00%
2016 Stock Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized						2,091,969
Shares remaining available for future issuance	228,852				0	228,852
2020 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares remaining available for future issuance					1,110,675
Number of shares of common stock that may be issued accordance with plan	1,220,283
Description of changes in the number of shares reserved for issuance					The number of shares reserved shall be annually increased on the first day of each fiscal year, beginning with the fiscal year ending December 31, 2021 and continuing until, and including, the fiscal year ending December 31, 2030, equal to the lesser of (i) 4% of the number of shares of the Company’s common stock outstanding on the first day of such fiscal year and (ii) an amount determined by the Company’s board of directors.
Common stock outstanding percent	4.00%
2020 Equity Incentive Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized	2,091,969
Number of shares of common stock that may be issued accordance with plan	8,541,982
2020 ESPP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized	193,216
Shares remaining available for future issuance					191,363
Number of shares of common stock that may be issued accordance with plan	386,432
Common stock outstanding percent	1.00%
Expected weighted average period to recognize expense					5 months 15 days
Offering price percentage	85.00%
Shares purchased under the ESPP					1,853
2020 ESPP | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense					$ 100,000
Unrecognized stock-based compensation expense					100,000
Earnings withheld from employees to purchase shares of common stock under purchase plan					$ 100,000

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Compensation Related Costs [Abstract]
Number of Shares, Beginning Balance	1,863,117
Number of Shares, Granted	759,139
Number of Shares, Exercised	(265,945)
Number of Shares, Forfeited	(420,679)
Number of Shares, Ending Balance	1,935,632	1,863,117
Number of Shares, Options vested and exercisable	602,986
Weighted-Average Exercise Price, Beginning Balance	$ 4.60
Weighted-Average Exercise Price, Granted	19.80
Weighted-Average Exercise Price, Exercised	4.34
Weighted-Average Exercise Price, Forfeited	8.02
Weighted-Average Exercise Price, Ending Balance	9.85	$ 4.60
Weighted-Average Exercise Price, Options vested and exercisable	$ 4.34
Weighted-Average Remaining Contractual Term, Outstanding	8 years 1 month 20 days	8 years 10 months 24 days
Weighted-Average Remaining Contractual Term, Options vested and exercisable	6 years 5 months 1 day
Aggregate Intrinsic Value, Balance	$ 24,260	$ 15,151
Aggregate Intrinsic Value, Options vested and exercisable	$ 10,678

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Stock-Based Compensation Fair Value Assumptions (Details) - Stock Options	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	6 years 2 months 1 day	6 years 1 month 9 days
Expected volatility	74.70%	69.30%
Expected dividend yield	0.00%	0.00%
Risk-free interest rate	0.52%	2.18%

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 2,231	$ 899
Research and Development Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	1,490	301
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 741	$ 598

Income Taxes - Schedule of Reco

Income Taxes - Schedule of Reconciliation of Income Tax Expense (Benefit) (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income taxes at U.S. statutory rate	21.00%	21.00%
State income taxes	6.00%	6.00%
Tax Credit	7.00%	3.00%
Other	2.00%	(1.00%)
Change in valuation allowance	(36.00%)	(29.00%)
Total provision for income taxes	0.00%	0.00%

Income Taxes - Schedule of Comp

Income Taxes - Schedule of Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets
Net operating loss carryforwards	$ 24,657	$ 13,284
Tax credits carryforwards	3,948	1,020
Stock-based compensation	686	246
Amortization	545	611
Accruals	272	200
Lease incentive liability	17	21
Other	42	31
Total deferred tax assets	30,167	15,413
Valuation allowance	(30,149)	(15,385)
Net deferred tax assets	18	28
Deferred tax liabilities
Tenant improvement allowance	(17)	(21)
Unrealized gains/losses on investments	(1)	(7)
Total deferred tax liabilities	$ (18)	$ (28)

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2017
Income Taxes [Line Items]
Valuation allowance increased	$ 14,800,000
Uncertain tax position	0
Federal
Income Taxes [Line Items]
Net operating loss carryforwards	$ 91,700,000	$ 48,600,000
Net operating loss carryforwards, limitations on use	The 2017 Tax Cuts and Jobs Act (“TCJA”) will generally allow losses incurred after 2017 to be carried over indefinitely but will generally limit the net operating loss deduction to the lesser of the net operating loss carryover or 80% of a corporation’s taxable income (subject to Section 382 of the Internal Revenue Code of 1986, as amended). Also, there will be no carryback for losses incurred after 2017. Losses incurred prior to 2018 will generally be deductible to the extent of the lesser of a corporation’s net operating loss carryover or 100% of a corporation’s taxable income and be available for twenty years from the period the loss was generated.
Net operating loss carryforwards expiration period	20 years
Net operating loss carryforwards not subject to expiration	$ 74,500,000
Net operating loss carryforwards subject to expiration			$ 17,200,000
Net operating loss carryforwards expiration year			2037
Net operating loss carryforwards expiration period CARES ACT	5 years
Net operating loss taxable income carryover percentage without limitation	80.00%
Tax credit carryforwards	$ 3,600,000	900,000
Tax credit carryforwards expiration year	2040
Unrecognized tax benefits	$ 0	0
Unrecognized tax benefits interest or penalties	0	0
State
Income Taxes [Line Items]
Net operating loss carryforwards	$ 85,500,000	48,900,000
Net operating loss carryforwards expiration year	2040
Unrecognized tax benefits	$ 0	0
Unrecognized tax benefits interest or penalties	0	0
State | Research and Development
Income Taxes [Line Items]
Tax credit carryforwards	$ 400,000	$ 100,000
Tax credit carryforwards expiration year	2035

Net Loss Per Share - Computatio

Net Loss Per Share - Computation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Numerator:
Net loss attributable to common stockholders—basic and diluted	$ (49,218)	$ (23,463)
Denominator:
Weighted-average common shares outstanding—basic and diluted	13,924,730	702,455
Net loss per share applicable to common stockholders—basic and diluted	$ (3.53)	$ (33.40)

Net Loss Per Share - Additional

Net Loss Per Share - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Earnings Per Share [Abstract]
Accretion of Series B convertible preferred stock	$ 7,858

Net Loss Per Share - Anti Dilut

Net Loss Per Share - Anti Dilutive Potential Common Shares Excluded From Computation of Diluted Net Loss Per Share (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Options to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted net loss per common share	1,935,632	1,863,117
Shares reserved for future issuance under the ESPP
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted net loss per common share	191,363
Series Seed Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted net loss per common share		430,693
Series A Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted net loss per common share		5,000,623
Series B Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted net loss per common share		4,178,645

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - USD ($)	Apr. 13, 2020	Mar. 16, 2020	Jan. 31, 2016	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Apr. 30, 2016
Related Party Transaction [Line Items]
Shares owned					60,533,313
Common stock, shares issued				17,548,263	702,510	17,548,263
Common Stock
Related Party Transaction [Line Items]
Number of common stock purchased				5,405,000
Initial Public Offering
Related Party Transaction [Line Items]
Number of common stock purchased	705,000	4,700,000
Lundbeckfond Invest A/S
Related Party Transaction [Line Items]
Ownership interest percentage				7.40%	9.30%	7.40%
Lundbeckfond Invest A/S | Initial Public Offering | Common Stock
Related Party Transaction [Line Items]
Number of common stock purchased		187,500
Lundbeck | Lundbeck Agreement
Related Party Transaction [Line Items]
Ownership interest percentage				2.70%	4.20%	2.70%
Common stock, shares issued					443,271		167,523
Upfront and ongoing milestone payments				$ 0
Lundbeck | Lundbeck Agreement | Research and Development Expense
Related Party Transaction [Line Items]
Upfront and ongoing milestone payments						$ 1,800,000
Cydan Development Incorporation
Related Party Transaction [Line Items]
Due to related party				$ 0	$ 0	$ 0
Cydan Development Incorporation | Business Services Agreement
Related Party Transaction [Line Items]
Related party, minimum percentage of capital stock owned			5.00%
Cydan Development Incorporation | Business Services Agreement | Research and Development Expense
Related Party Transaction [Line Items]
Payments to related party on related services					$ 300,000
Series A Preferred Stock
Related Party Transaction [Line Items]
Shares owned					31,499,040
Series A Preferred Stock | Lundbeckfond Invest A/S
Related Party Transaction [Line Items]
Shares owned					5,470,492
Series A Preferred Stock | Lundbeck | Lundbeck Agreement
Related Party Transaction [Line Items]
Shares owned					499,069
Series Seed Preferred Stock
Related Party Transaction [Line Items]
Shares owned					2,712,960
Series Seed Preferred Stock | Lundbeckfond Invest A/S
Related Party Transaction [Line Items]
Shares owned					478,749
Series B Preferred Stock
Related Party Transaction [Line Items]
Shares owned					26,321,313
Series B Preferred Stock | Lundbeckfond Invest A/S
Related Party Transaction [Line Items]
Shares owned					1,326,111

Benefit Plans - Additional Info

Benefit Plans - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Defined Contribution Savings Plan
Defined Contribution Plan Disclosure [Line Items]
Contribution to defined contribution savings plan	$ 100,000	$ 0