Praxis Precision Medicines (PRAX) 10-Q 13 May 24 2024 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2024	May 09, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2024
Document Transition Report	false
Entity File Number	001-39620
Entity Registrant Name	PRAXIS PRECISION MEDICINES, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	47-5195942
Entity Address, Address Line One	99 High Street
Entity Address, Address Line Two	30th Floor
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02110
City Area Code	617
Local Phone Number	300-8460
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Trading Symbol	PRAX
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		17,107,887
Amendment Flag	false
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1
Entity Central Index Key	0001689548
Current Fiscal Year End Date	--12-31

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 151,980	$ 81,300
Marketable securities	55,436	0
Prepaid expenses and other current assets	4,388	3,580
Total current assets	211,804	84,880
Long-term marketable securities	35,873	0
Property and equipment, net	476	588
Operating lease right-of-use assets	1,840	2,064
Other non-current assets	416	416
Total assets	250,409	87,948
Current liabilities:
Accounts payable	9,404	5,815
Accrued expenses	6,976	7,416
Operating lease liabilities	1,158	1,126
Current portion of deferred revenue	1,256	1,392
Total current liabilities	18,794	15,749
Long-term liabilities:
Non-current portion of operating lease liabilities	1,066	1,369
Non-current portion of deferred revenue	866	1,161
Total liabilities	20,726	18,279
Commitments and contingencies (Note 6)
Stockholders’ equity:
Preferred stock, $0.0001 par value; 10,000,000 shares authorized and no shares issued or outstanding as of March 31, 2024 and December 31, 2023	0	0
Common stock, $0.0001 par value; 150,000,000 shares authorized; 13,258,047 shares issued and outstanding as of March 31, 2024, and 8,791,877 shares issued and outstanding as of December 31, 2023	13	13
Additional paid-in capital	923,141	723,577
Accumulated other comprehensive income	3	0
Accumulated deficit	(693,474)	(653,921)
Total stockholders’ equity	229,683	69,669
Total liabilities and stockholders’ equity	$ 250,409	$ 87,948

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Mar. 31, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, authorized (in shares)	10,000,000	10,000,000
Preferred stock, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, authorized (in shares)	150,000,000	150,000,000
Common stock, issued (in shares)	13,258,047	8,791,877
Common stock, outstanding (in shares)	13,258,047	8,791,877

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2024	Mar. 31, 2023
Income Statement [Abstract]
Collaboration revenue		$ 431	$ 683
Operating expenses:
Research and development		26,984	25,504
General and administrative		15,333	13,270
Total operating expenses		42,317	38,774
Loss from operations		(41,886)	(38,091)
Other income:
Other income, net		2,333	636
Total other income		2,333	636
Net loss		$ (39,553)	$ (37,455)
Net loss per share attributable to common stockholders, basic (in dollars per share)	[1]	$ (2.84)	$ (10.58)
Net loss per share attributable to common stockholders, diluted (in dollars per share)	[1]	$ (2.84)	$ (10.58)
Weighted average common shares outstanding, basic (in shares)	[1]	13,904,374	3,540,185
Weighted average common shares outstanding, diluted (in shares)	[1]	13,904,374	3,540,185
[1] Results have been retroactively adjusted to reflect the 1-for-15 reverse stock split effected on November 28, 2023. See Note 2 for details.

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Operations (Unaudited) (Parenthetical)	Nov. 28, 2023
Income Statement [Abstract]
Stockholders' equity note, stock split, conversion ratio	0.0667

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Statement of Comprehensive Income [Abstract]
Net loss	$ (39,553)	$ (37,455)
Change in unrealized gains on marketable securities, net of tax	3	154
Comprehensive loss	$ (39,550)	$ (37,301)

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Stockholders’ Equity (Unaudited) - USD ($) $ in Thousands		Total	Follow-On Offering	At-The-Market Offering	License And Collaboration Agreement	Common Stock		Common Stock Follow-On Offering	Common Stock At-The-Market Offering	Common Stock License And Collaboration Agreement	Additional Paid-In Capital	Additional Paid-In Capital Follow-On Offering	Additional Paid-In Capital At-The-Market Offering	Additional Paid-In Capital License And Collaboration Agreement	Accumulated Deficit	Accumulated Other Comprehensive Loss
Beginning balance (in shares) at Dec. 31, 2022	[1]					3,292,163
Beginning balance at Dec. 31, 2022		$ 76,106				$ 5	[1]				$ 606,918				$ (530,644)	$ (173)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense		7,593									7,593
Stock issuance costs				$ 560
Issuance of common stock (in shares)	[1]					560,253
Issuance of common stock		18,096				$ 1	[1]				18,095
Vesting of restricted stock awards (in shares)	[1]					11,516
Shares withheld for taxes for vesting of restricted stock units (in shares)	[1]					(2,875)
Shares withheld for taxes for vesting of restricted stock units		(127)									(127)
Issuance of common stock upon exercise of stock options (in shares)	[1]					2,970
Issuance of common stock upon exercise of stock options		101									101
Change in unrealized gain on marketable securities, net of tax		154														154
Net loss		(37,455)													(37,455)
Ending balance (in shares) at Mar. 31, 2023	[1]					3,864,027
Ending balance at Mar. 31, 2023		$ 64,468				$ 6	[1]				632,580				(568,099)	(19)
Beginning balance (in shares) at Dec. 31, 2023		8,791,877				8,791,877
Beginning balance at Dec. 31, 2023		$ 69,669				$ 13					723,577				(653,921)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense		14,475									14,475
Stock issuance costs			$ 10,836	376
Issuance of common stock (in shares)								3,802,025	209,852	443,253
Issuance of common stock			$ 161,649	$ 6,169	$ 17,265							$ 161,649	$ 6,169	$ 17,265
Vesting of restricted stock awards (in shares)						11,095
Shares withheld for taxes for vesting of restricted stock units (in shares)						(3,689)
Shares withheld for taxes for vesting of restricted stock units		$ (137)									(137)
Issuance of common stock upon exercise of stock options (in shares)		3,634				3,634
Issuance of common stock upon exercise of stock options		$ 143									143
Change in unrealized gain on marketable securities, net of tax		3														3
Net loss		$ (39,553)													(39,553)
Ending balance (in shares) at Mar. 31, 2024		13,258,047				13,258,047
Ending balance at Mar. 31, 2024		$ 229,683				$ 13					$ 923,141				$ (693,474)	$ 3
[1] Results have been retroactively adjusted to reflect the 1-for-15 reverse stock split effected on November 28, 2023. See Note 2 for details.

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Stockholders’ Equity (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Follow-On Offering
Stock issuance costs	$ 10,836
At-The-Market Offering
Stock issuance costs	$ 376	$ 560

Condensed Consolidated Statem_6

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash flows from operating activities:
Net loss	$ (39,553)	$ (37,455)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation expense	112	106
Stock-based compensation expense	14,475	7,593
Non-cash operating lease expense	224	201
Amortization of premiums and discounts on marketable securities, net	(84)	45
Non-cash collaboration and license agreement expense	2,500	0
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(808)	1,771
Accounts payable	3,589	2,314
Accrued expenses	(608)	(6,498)
Operating lease liabilities	(271)	(240)
Deferred revenue	(431)	(683)
Other	(2)	0
Net cash used in operating activities	(20,857)	(32,846)
Cash flows from investing activities:
Purchases of marketable securities	(91,220)	0
Maturities of marketable securities	0	34,000
Net cash (used in) provided by investing activities	(91,220)	34,000
Cash flows from financing activities:
Payments of tax withholdings related to vesting of restricted stock units	(137)	(127)
Proceeds from exercise of stock options and employee stock purchase plan purchases	143	101
Net cash provided by financing activities	182,757	18,070
Increase in cash, cash equivalents and restricted cash	70,680	19,224
Cash, cash equivalents and restricted cash, beginning of period	81,716	62,031
Cash, cash equivalents and restricted cash, end of period	152,396	81,255
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	151,980	80,839
Restricted cash	416	416
Total cash, cash equivalents and restricted cash	152,396	81,255
Supplemental disclosures of non-cash activities:
Issuance costs from at-the-market offering included in accrued expenses	168	0
Follow-On Offering
Cash flows from financing activities:
Proceeds from stock offerings, net of issuance costs	161,649	0
License And Collaboration Agreement
Cash flows from financing activities:
Proceeds from stock offerings, net of issuance costs	14,765	0
At-The-Market Offering
Cash flows from financing activities:
Proceeds from stock offerings, net of issuance costs	$ 6,337	$ 18,096

Nature of the Business

Nature of the Business	3 Months Ended
	Mar. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of the Business	Nature of the Business Praxis Precision Medicines, Inc. (“Praxis” or the “Company”) is a clinical-stage biopharmaceutical company translating insights from genetic epilepsies into the development of therapies for central nervous system ("CNS"), disorders characterized by neuronal excitation-inhibition imbalance. Normal brain function requires a delicate balance of excitation and inhibition in neuronal circuits, which, when dysregulated, can lead to abnormal function and both rare and more prevalent neurological disorders. The Company is applying genetic insights to the discovery and development of therapies for neurological disorders through two proprietary platforms, using its understanding of shared biological targets and circuits in the brain. Each platform has multiple programs currently, with significant potential for additional program and indication expansion: • Cerebrum ™, the Company's small molecule platform, utilizes deep understanding of neuronal excitability and neuronal networks and applies a series of computational and experimental tools to develop orally available precision therapies • Solidus ™, the Company's antisense oligonucleotide, or ASO, platform, is an efficient, targeted precision medicine discovery and development engine anchored on a proprietary, computational methodology The Company's platforms utilize a deliberate, pragmatic and patient-guided approach, leveraging a suite of translational tools, including novel transgenic and predictive translational animal models and electrophysiology markers, to enable an efficient path to proof-of-concept in patients. Through this approach, the Company has established a diversified, multimodal CNS portfolio with four clinical-stage product candidates across movement disorders and epilepsy. For the Company's most advanced product candidate under the Cerebrum™ platform, ulixacaltamide (formerly known as PRAX-944), it expects to announce topline results from the ongoing Phase 3 Essential3 clinical trials in essential tremor in the second half of 2024. Within the Company's PRAX-628 program, it announced positive results from its Photo-Paroxysmal Response ("PPR") study in the first quarter of 2024 and plans to initiate the first of two efficacy studies of PRAX-628 in focal onset seizures in the second half of 2024, with topline results expected in 2025. The Company plans to initiate a second PRAX-628 efficacy study in focal onset seizures in the first half of 2025, with topline results expected in the first half of 2026. The Company's PRAX-562 Phase 2 EMBOLD study was initiated in the first quarter of 2023, with cohorts in SCN2A-DEE and SCN8A-DEE; topline results are expected for both cohorts in the third quarter of 2024. For the Company's most advanced product candidate under the Solidus™ platform, elsunersen (formerly known as PRAX-222), it shared results from Part 1 of the EMBRAVE study in the fourth quarter of 2023, and is currently completing multiple global regulatory interactions in anticipation of starting the pivotal phase of the program later in 2024. Praxis was incorporated in 2015 and commenced operations in 2016. The Company has funded its operations primarily with proceeds from the issuance of redeemable convertible preferred stock, from the sale of common stock through an initial public offering and at-the-market offerings under its shelf registration statement, and from follow-on public offerings of common stock and pre-funded warrants to purchase common stock. From inception through March 31, 2024, the Company raised $785.3 million in aggregate cash proceeds from these transactions, net of issuance costs. In April 2024, the Company raised net proceeds of $215.8 million from a follow-on public offering of common stock and pre-funded warrants. 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. Programs currently under development 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. Liquidity In accordance with the Financial Accounting Standards Board (“FASB”) Accounting Standards Update (“ASU”) 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (Subtopic 205-40) , the Company has evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date that these condensed consolidated financial statements are issued. The Company has incurred recurring losses since its inception, including a net loss of $39.6 million for the three months ended March 31, 2024. In addition, as of March 31, 2024, the Company had an accumulated deficit of $693.5 million. The Company expects to continue to generate operating losses for the foreseeable future. The Company expects that its cash, cash equivalents and marketable securities as of March 31, 2024 of $243.3 million will be sufficient to fund its operating expenditures and capital expenditure requirements necessary to advance its research efforts and clinical trials for at least one year from the date of issuance of these condensed consolidated financial statements. The future viability of the Company is dependent on its ability to raise additional capital to finance its operations. The Company's inability to raise capital as and when needed could have a negative impact on its financial condition and ability to pursue its business strategies. There can be no assurance that the current operating plan will be achieved or that additional funding will be available on terms acceptable to the Company, or at all.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2024
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation The accompanying condensed consolidated financial statements have been prepared in conformity with generally accepted accounting principles 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 ASUs of the FASB. The significant accounting policies used in preparation of these condensed consolidated financial statements for the three months ended March 31, 2024 are consistent with those discussed in Note 2 to the consolidated financial statements included in the Company's 2023 Annual Report on Form 10-K, other than as noted below. Reverse Stock Split On November 28, 2023, the Company filed a Certificate of Amendment to the Company's Amended and Restated Certificate of Incorporation with the Secretary of State of the State of Delaware to effect a 1-for-15 reverse stock split of its common stock (the "Reverse Stock Split"). The Reverse Stock Split became effective at 5:00 p.m., Eastern Time, on November 28, 2023 (the "Effective Time"). As a result of the Reverse Stock Split, every 15 shares of the Company's issued and outstanding common stock were automatically reclassified into one validly issued, fully-paid and non-assessable share of common stock. Any fractional post-split shares as a result of the Reverse Stock Split were rounded down to the nearest whole post-split share. The Reverse Stock Split did not affect the number of authorized shares of common stock or the par value of the common stock. All share amounts and per share amounts for the periods prior to the Effective Time disclosed in this Quarterly Report on Form 10-Q have been restated to reflect the Reverse Stock Split on a retroactive basis. Marketable Securities Classification The Company may invest its excess cash in money market funds and debt instruments of the U.S. Treasury, financial institutions, corporations and U.S. government agencies with strong credit ratings and an investment grade rating at or above A-1 or P-1 by two of the three nationally recognized statistical rating organizations. The Company does not believe that it is exposed to more than a nominal amount of credit risk related to any marketable securities it may invest in. The Company has established guidelines relative to diversification and maturities that maintain safety and liquidity, and periodically reviews and modifies these guidelines to maximize trends in yields and interest rates without compromising safety and liquidity. The Company classifies its investments in debt instruments as available-for-sale. Available-for-sale investments are reported at fair value at each balance sheet date, and include any unrealized holding gains and losses in accumulated other comprehensive loss, a component of stockholders’ equity. Realized gains and losses are included in the Company's condensed consolidated statements of operations. All of the Company's available-for-sale securities are available for use in its current operations. The Company classifies marketable securities as either cash equivalents, short-term, or long-term based on their stated maturity dates as it is more-likely-than-not that the Company will hold these assets through to their maturity dates. Unaudited Interim Condensed Consolidated Financial Information The accompanying condensed consolidated balance sheet as of March 31, 2024, the condensed consolidated statements of operations for the three months ended March 31, 2024 and 2023, the condensed consolidated statements of comprehensive loss for the three months ended March 31, 2024 and 2023, the condensed consolidated statements of cash flows for the three months ended March 31, 2024 and 2023 and the condensed consolidated statements of stockholders’ equity for the three months ended March 31, 2024 and 2023 are unaudited. The unaudited interim financial statements have been prepared on the same basis as the audited annual consolidated financial statements, and in the opinion of management reflect all adjustments, which include only normal recurring adjustments necessary for the fair statement of the Company’s financial position as of March 31, 2024, the results of its operations for the three months ended March 31, 2024 and 2023 and its cash flows for the three months ended March 31, 2024 and 2023. Financial statement disclosures for the three months ended March 31, 2024 and 2023 are condensed and do not include all disclosures required for an annual set of financial statements in accordance with GAAP. The results for the three months ended March 31, 2024 are not necessarily indicative of results to be expected for the year ended December 31, 2024, any other interim periods, or any future year or period. Use of Estimates The preparation of condensed 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 condensed consolidated financial statements and the reported amounts of expenses during the reporting periods. Significant estimates and assumptions reflected in these condensed consolidated financial statements include, but are not limited to, accrued and prepaid research and development expense, collaboration revenue, stock-based compensation expense and the recoverability of the Company’s net deferred tax assets and related valuation allowance. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Changes in estimates are recorded in the period in which they become known. Actual results could differ materially from those estimates. Common Stock Warrants The Company accounts for warrants to purchase shares of its common stock in accordance with the guidance in FASB ASC No. 480, Distinguishing Liabilities from Equity (ASC 480) and ASC No. 815, Derivatives and Hedging (ASC 815). The Company classifies warrants issued for the purchase of shares of its common stock as either equity or liability instruments based on an assessment of the specific terms and conditions of each respective contract. Such assessment includes determining whether the warrants are freestanding financial instruments or embedded in a host instrument, whether the warrants are liabilities within the scope of ASC 480, whether the warrants meet the definition of a derivative in ASC 815 and whether the warrants meet the requirements for equity classification pursuant to the indexation and equity classification criteria in ASC 815. The Company determines the classification for its warrants at the time of issuance and updates its assessment, as necessary. Warrants that meet all of the criteria for equity classification are recorded as a component of additional paid-in capital. Net Loss per Share Basic net loss per share is computed by dividing net loss by the weighted average number of common shares outstanding for the period. The calculation of weighted average number of common shares outstanding excludes shares of restricted common stock that are not vested but includes shares of common stock underlying pre-funded warrants. Diluted net loss per share is computed by dividing net loss by the weighted average number of common shares outstanding for the period, after giving consideration to the dilutive effect of potentially dilutive common shares. For purposes of this calculation, outstanding options to purchase shares of common stock, unvested shares of restricted common stock and potential shares issuable under the 2020 ESPP are considered potentially dilutive common shares. The Company has generated a net loss in all periods presented so the basic and diluted net loss per share are the same, as the inclusion of the potentially dilutive securities would be anti-dilutive. Recent Accounting Pronouncements Recently Issued Accounting Pronouncements On November 27, 2023, the FASB issued ASU No. 2023-07, Segment Reporting (Topic 280) - Improvements to Reportable Segment Disclosures . ASU No. 2023-07 improves reportable segment disclosure requirements, primarily through enhanced disclosures about significant segment expenses. The amendments included in this ASU apply to all public entities that are required to report segment information in accordance with Topic 280, including those with a single reportable segment. The amendments are effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024. Early adoption is permitted and should be applied retrospectively to all prior periods presented in the financial statements. Upon transition, the segment expenses categories and amounts disclosed in the prior periods should be based on the significant segment expense categories identified and disclosed in the period of adoption. The Company only has one reportable segment and this ASU impacts disclosures only. The Company has determined that the effects of adopting the amendments in ASU 2023-07 will only impact its disclosures and not have a material impact on its consolidated financial position and the results of its operations when such amendment is adopted. On December 14, 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740) - Improvements to Income Tax Disclosures . ASU No. 2023-09 provides more transparency about income tax information through improvements to income tax disclosures primarily related to the rate reconciliation and incomes taxes paid information. For public companies, the amendments are effective for annual periods beginning after December 15, 2024 and should be applied prospectively. The Company has determined that the effects of adopting the amendments in ASU 2023-09 will only impact its disclosures and will not have a material impact on its consolidated financial position and the results of its operations when such amendment is adopted.

Cash Equivalents and Marketable

Cash Equivalents and Marketable Securities	3 Months Ended
	Mar. 31, 2024
Investments, Debt and Equity Securities [Abstract]
Cash Equivalents and Marketable Securities	Cash Equivalents and Marketable Securities The following is a summary of the Company's investment portfolio as of March 31, 2024. The Company did not hold any cash equivalents or marketable securities as of December 31, 2023 (in thousands): As of March 31, 2024 Gross Unrealized Estimated Cost Gains Losses Fair Value Cash equivalents: Money market funds $ 15,971 $ — $ — $ 15,971 Debt securities issued by U.S. government agencies 17,889 — — 17,889 Corporate debt securities 12,009 — (1) 12,008 Commercial paper 2,450 — (1) 2,449 Available-for-sale marketable securities: Debt securities issued by U.S. government agencies 59,722 12 — 59,734 Corporate debt securities 26,602 — (2) 26,600 Commercial paper 1,934 — (3) 1,931 Other debt securities 3,046 — (2) 3,044 Total cash equivalents and marketable securities $ 139,623 $ 12 $ (9) $ 139,626 As of March 31, 2024, the Company had 33 securities with a total fair market value of $42.6 million in an unrealized loss position. The Company believes that any unrealized losses associated with the decline in value of its securities is temporary and primarily related to the change in market interest rates since purchase, and believes that it is more likely than not that it will be able to hold its debt securities to maturity. The Company anticipates a full recovery of the amortized cost basis of its debt securities at maturity and an allowance was not recognized. Contractual maturities of the marketable securities at each balance sheet date are as follows (in thousands): March 31, 2024 December 31, 2023 Within one year $ 87,782 $ — After one year through five years 35,873 — Total $ 123,655 $ — Securities are evaluated for impairment at the end of each reporting period. The Company did not record any impairment related to its available-for-sale securities during the three months ended March 31, 2024 and 2023.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2024
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Fair value is defined as the price that would be received to sell an asset in an orderly transaction between market participants at the measurement date. The Company categorizes financial assets measured at fair value based on a fair value hierarchy. The following fair value hierarchy is used to classify financial assets based on observable inputs and unobservable inputs used to value the financial assets: • Level 1: Unadjusted quoted prices in active markets that are accessible at the measurement date for identical assets; • Level 2: Quoted prices for similar assets in active markets, quoted prices in markets that are not active, or inputs which are unobservable, either directly or indirectly, for substantially the full term of the asset; or • Level 3: Prices or valuation techniques that require inputs that are both significant to the valuation of the asset and unobservable. The following table presents information about the Company’s financial assets measured at fair value on a recurring basis and indicates the level of the fair value hierarchy utilized to determine such fair values as of March 31, 2024 (in thousands). The Company did not hold any financial assets measured at fair value on a recurring basis as of December 31, 2023: As of March 31, 2024 Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 15,971 $ — $ — $ 15,971 Debt securities issued by U.S. government agencies 17,889 — — 17,889 Corporate debt securities — 12,008 — 12,008 Commercial paper — 2,449 — 2,449 Available-for-sale marketable securities: Debt securities issued by U.S. government agencies 59,734 — — 59,734 Corporate debt securities — 26,600 — 26,600 Commercial paper — 1,931 — 1,931 Other debt securities — 3,044 — 3,044 $ 93,594 $ 46,032 $ — $ 139,626

Accrued Expenses

Accrued Expenses	3 Months Ended
	Mar. 31, 2024
Payables and Accruals [Abstract]
Accrued Expenses	Accrued Expenses Accrued expenses consisted of the following (in thousands): March 31, 2024 December 31, 2023 Accrued external research and development expenses $ 4,717 $ 2,957 Accrued personnel-related expenses 1,661 3,716 Accrued other expenses 598 743 Total accrued expenses $ 6,976 $ 7,416

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies In May 2021, the Company entered into a sublease agreement for office space located in Boston, Massachusetts that expires on January 31, 2026, with no option to renew or terminate early. The base rent increases by approximately 2% annually. The Company issued a letter of credit to the landlord related to the security deposit, secured by restricted cash, which is reflected within other non-current assets on the accompanying condensed consolidated balance sheets as of March 31, 2024 and December 31, 2023. This lease qualifies as an operating lease.

Collaboration License Agreement

Collaboration License Agreements	3 Months Ended
	Mar. 31, 2024
Revenue from Contract with Customer [Abstract]
Collaboration License Agreements	Collaboration and License Agreements UCB Option and License Agreement In December 2022, the Company entered into an Option and License Agreement (“the Collaboration Agreement”) with UCB Biopharma SRL (“UCB”) for the discovery of small molecule therapeutics as potential treatments of KCNT1-related epilepsies. Under the terms of the Collaboration Agreement, the Company has agreed to perform general biology-related research services as part of a mutually agreed upon research plan in exchange for a $5.0 million upfront payment. In addition, the Company provided UCB an exclusive option to in-license global development and commercialization rights to any resulting KCNT1 small molecule development candidate identified as part of the research plan. If UCB exercises its option to in-license global development and commercialization rights, the Collaboration Agreement stipulates that UCB will assume research, development, manufacturing and commercialization responsibilities and costs. Under the terms of the Collaboration Agreement, the Company will be eligible to receive an option fee and future success-based development and commercialization milestone payments, totaling up to $98.5 million, in addition to tiered royalties on net sales of any resulting products from the Collaboration Agreement. The Company concluded that UCB is a customer, and as such, the arrangement falls within the scope of Topic 606. At the commencement of the Collaboration Agreement, the Company identified one performance obligation, which was to perform the research services for UCB. The Company determined the transaction price to be $5.0 million, comprised of the upfront payment it received. The option provided to UCB was determined not to be a material right. The Company recognizes revenue for its research services performance obligation over time using an input method over the duration of the research services. During the three months ended March 31, 2024, the Company recognized $0.4 million in collaboration revenue related to the Collaboration Agreement in the condensed consolidated statement of operations. As of March 31, 2024, $2.1 million was included in deferred revenue in the condensed consolidated balance sheet, of which $1.3 million was classified as current. Tenacia Collaboration and License Agreement On January 4, 2024, the Company entered into an exclusive collaboration and license Agreement (“the License Agreement”) with Tenacia Biotechnology (Shanghai) Co., Ltd. (“Tenacia”), a China-based portfolio company of Bain Capital, which provides Tenacia an exclusive license to use certain intellectual property for the development and commercialization of ulixacaltamide and products containing ulixacaltamide in China, Hong Kong, Macau and Taiwan. Tenacia is solely responsible for the development and commercialization under the arrangement, with the exception of the associated manufacturing. The Company also entered into a Stock Purchase Agreement (“the Stock Purchase Agreement”) with BCPE Tenet Holdings Cayman, Ltd. (“BCPE”), a related party of Tenacia. Pursuant to the terms of the License Agreement, the Company was entitled to an up-front, non-refundable and non-creditable cash payment of $5.0 million, net of certain tax withholdings. In addition, the Company is eligible to receive $264.0 million in success-based development and commercialization milestone payments as well as tiered royalties on net sales. Pursuant to the terms of the Stock Purchase Agreement, the Company issued and sold 443,253 shares of its common stock to BCPE at a price per share of $22.5605 for aggregate gross proceeds of $10.0 million. The per share price was based on a 20% premium over the 30-day volume-weighted average price. Under the terms of the License Agreement, the Company granted to Tenacia an exclusive license to use certain intellectual property for the development and commercialization of ulixacaltamide and products containing ulixacaltamide in China, Hong Kong, Macau and Taiwan. Tenacia is solely responsible for the development and commercialization under the arrangement, with the exception of the associated manufacturing. The Company concluded that the License Agreement and the Stock Purchase Agreement is a combined arrangement since they were executed at the same time and in contemplation of each other with the same counterparty or a related party thereof and the combined arrangement falls within the scope of Topic 606. The Company’s obligations under the arrangement comprise a single promise, or one performance obligation, related to the exclusive development and commercialization license granted to Tenacia. Total proceeds associated with the combined arrangement at inception were $14.8 million consisting of the following: (i) $10.0 million gross proceeds from the sale of common stock under the Stock Purchase Agreement and (ii) $4.8 million, net of tax, related to the up-front payment under the License Agreement, both of which were received in January 2024. During the three months ended March 31, 2024, the Company had not achieved any development or sales milestones or earned any royalties under the License Agreement. The Company recorded the common stock sold to BCPE at its issuance date fair value of $38.95 per share, or $17.3 million in the aggregate, which exceeded the proceeds received which were calculated based on the 20% premium over the prior 30-day volume-weighted average price. Accordingly, there is no transaction price allocable to the performance obligation as of March 31, 2024. The Company accounted for the excess of the fair value of the equity securities issued over the total proceeds received as consideration paid to a customer for which no distinct good or service was transferred in exchange. As a result, the transaction gives rise to negative revenue on a cumulative basis in the amount of $2.5 million, which was recorded in research and development expense in the accompanying condensed consolidated statement of operations for the three months ended March 31, 2024. For agreements where the licenses are considered separate performance obligations or represent the only performance obligation, the Company recognizes revenue at the point in time that the Company effectively grants the license, as the licenses or assignments represent functional intellectual property.

Common Stock and Preferred Stoc

Common Stock and Preferred Stock	3 Months Ended
	Mar. 31, 2024
Stockholders' Equity Note [Abstract]
Common Stock and Preferred Stock	Common Stock and Preferred Stock Reverse Stock Split On November 28, 2023, the Company filed a Certificate of Amendment to the Company's Amended and Restated Certificate of Incorporation with the Secretary of State of the State of Delaware to effect a 1-for-15 reverse stock split of its common stock. The Reverse Stock Split became effective at 5:00 p.m., Eastern Time, on November 28, 2023. As a result of the Reverse Stock Split, every 15 shares of the Company's issued and outstanding common stock were automatically reclassified into one validly issued, fully-paid and non-assessable share of common stock. Any fractional post-split shares as a result of the Reverse Stock Split were rounded down to the nearest whole post-split share. The Reverse Stock Split did not affect the number of authorized shares of common stock or the par value of the common stock. All share amounts and per share amounts for the period prior to the Effective Time disclosed in this Quarterly Report on Form 10-Q have been restated to reflect the Reverse Stock Split on a retroactive basis. Common Stock As of March 31, 2024 and December 31, 2023, the authorized capital stock of the Company included 150,000,000 shares of common stock, $0.0001 par value. As of March 31, 2024 and December 31, 2023, the Company did not hold any treasury shares. Follow-On Public Offerings June 2023 Public Offering On June 21, 2023, the Company completed a public offering of: (i) an aggregate of 4,296,646 shares of its common stock at a public offering price of $14.25 per share, including the underwriters’ full exercise of their option to purchase 619,979 additional shares of common stock, and (ii) pre-funded warrants to purchase 470,000 shares of common stock at a public offering price of $14.2485 per share of common stock underlying the warrants. The purchase price per share for each pre-funded warrant represents the per share offering price for the common stock, less the $0.0015 per share exercise price for each underlying share. Total net proceeds generated from the offering were approximately $63.4 million, after deducting underwriting discounts, commissions and other offering expenses payable by the Company. The pre-funded warrants are exercisable at any time on or after the date of issuance at the option of the holder, subject to a beneficial ownership blocker that may limit exercisability. No holder may exercise any portion of the warrants that would cause either the aggregate number of shares of common stock beneficially owned by such holder, together with its affiliates, to exceed 9.99%, or the combined voting power of the securities beneficially owned by such holder, together with its affiliates, to exceed 9.99%. A holder of a pre-funded warrant may increase or decrease this percentage up to 19.99% by providing at least 61 days’ prior notice to the Company. The pre-funded warrants do not expire. The pre-funded warrants may be settled through either physical or net share settlement. Following the occurrence of certain fundamental transactions, the holders of the pre-funded warrants have the right to receive upon exercise of the warrants the same amount and kind of securities, cash, or property as they would have been entitled to receive if they had been holders of the common shares issuable under the warrants immediately prior to such transaction. In the event of certain fundamental transactions where the consideration payable to the holders of shares of common stock consists solely of cash and/or marketable securities, the pre-funded warrants will automatically be deemed to be exercised in full pursuant to a cashless exercise effective immediately prior to and contingent upon the consummation of such transaction. As of March 31, 2024, none of the pre-funded warrants had been exercised and all remain outstanding. January 2024 Public Offering On January 16, 2024, the Company completed a public offering of: (i) an aggregate of 3,802,025 shares of its common stock at a public offering price of $35.50 per share, including the underwriters' full exercise of their option to purchase 633,750 additional shares of commons stock, and (ii) pre-funded warrants to purchase 1,056,725 shares of common stock at a public offering price of $35.4999 per share of common stock underlying the warrants. The purchase price per share of each pre-funded warrant represents the per share offering price for the common stock, less the $0.0001 per share exercise price of each underlying share. Total net proceeds generated from the offering were approximately $161.6 million, after deducting underwriting discounts, commissions and other offering expenses payable by the Company. The pre-funded warrants are exercisable at any time on or after the date of issuance at the option of the holder, subject to a beneficial ownership blocker that may limit exercisability. No holder may exercise any portion of the warrants that would cause either the aggregate number of shares of common stock beneficially owned by such holder, together with its affiliates, to exceed 4.99% (or 9.99%), or the combined voting power of the securities beneficially owned by such holder, together with its affiliates, to exceed 4.99% (or 9.99%). A holder of a pre-funded warrant may increase or decrease this percentage up to 19.99% by providing at least 61 days’ prior notice to the Company. The pre-funded warrants do not expire. The pre-funded warrants may be settled through either physical or net share settlement. Following the occurrence of certain fundamental transactions, the holders of the pre-funded warrants have the right to receive upon exercise of the warrants the same amount and kind of securities, cash, or property as they would have been entitled to receive if they had been holders of the common shares issuable under the warrants immediately prior to such transaction. As of March 31, 2024, none of the pre-funded warrants had been exercised and all remained outstanding. The Company determined that the pre-funded warrants related to both the June 2023 and January 2024 public offerings are freestanding financial instruments because they are both legally detachable and separately exercisable from the common stock sold in the offering. As such, the Company evaluated the pre-funded warrants to determine whether they represent instruments that require liability classification pursuant to the guidance in ASC 480. However, the Company concluded that the pre-funded warrants are not a liability within the scope of ASC 480 due to their characteristics. Further, the Company determined that the pre-funded warrants do not meet the definition of a derivative under ASC 815 because they do not meet the criteria regarding no or little initial net investment. Accordingly, the Company assessed the pre-funded warrants relative to the guidance in ASC No. 815-40, Contracts in Entity’s Own Equity , to determine the appropriate treatment. The Company concluded that the pre-funded warrants are both indexed to its own stock and meet all other conditions for equity classification. Accordingly, the Company has classified the pre-funded warrants as permanent equity. Shares Reserved for Future Issuance The Company has reserved the following shares of common stock for future issuance: March 31, December 31, Shares reserved for exercise of outstanding stock options 1,084,026 666,163 Shares reserved for exercise of pre-funded warrants related to the June 2023 Financing 470,000 470,000 Shares reserved for exercise of pre-funded warrants related to the January 2024 Financing 1,056,725 — Shares reserved for future awards under the 2020 Stock Option and Incentive Plan 111,028 148,264 Shares reserved for future awards under the 2020 Employee Stock Purchase Plan 141,029 53,111 Shares reserved for future awards under the 2024 Inducement Plan 996,950 — Shares reserved for vesting of restricted stock units 97,601 47,145 Total shares of authorized common stock reserved for future issuance 3,957,359 1,384,683 Preferred Stock As of March 31, 2024 and December 31, 2023, the authorized capital stock of the Company included 10,000,000 shares of undesignated preferred stock, $0.0001 par value.

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2024
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation 2024 Inducement Plan In January 2024, the Board of Directors ("the Board") adopted the 2024 Inducement Plan (the "Inducement Plan") without stockholder approval pursuant to Rule 5635(c)(4) of the Nasdaq Stock Market LLC listing rules ("Rule 5635(c)(4)"). In accordance with Rule 5635(c)(4), the Inducement Plan allows the Company to grant awards only to a newly hired employee who was not previously an employee or non-employee director or to an employee who is being rehired following a bona fide period of non-employment if such award is a material inducement to such employee entering into employment. The total number of shares of common stock authorized for issuance under the Inducement Plan as of March 31, 2024 was 1,000,000 shares. 2020 Stock Option and Incentive Plan The total number of shares of common stock authorized for issuance under the 2020 Stock Option and Incentive Plan (the "2020 Plan”) as of March 31, 2024 and December 31, 2023 was 1,100,833 shares and 661,240 shares, respectively. 2017 Stock Incentive Plan The total number of shares of common stock authorized for issuance under the 2017 Stock Incentive Plan (the "2017 Plan") as of March 31, 2024 and December 31, 2023 was 395,850 shares. Any authorization to issue new options under the 2017 Plan was cancelled upon the effectiveness of the 2020 Plan and no further awards will be granted under the 2017 Plan. 2020 Employee Stock Purchase Plan The total number of shares of common stock authorized for issuance under the 2020 Employee Stock Purchase Plan (the "2020 ESPP”) as of March 31, 2024 and December 31, 2023 was 175,145 shares and 87,227 shares, respectively. Restricted Stock Units The following table summarizes the Company’s restricted stock unit activity: Shares Weighted Unvested as of December 31, 2023 47,145 $ 202.27 Issued 65,333 43.35 Vested (11,346) 316.60 Forfeited (3,531) 35.63 Unvested as of March 31, 2024 97,601 $ 88.63 As of March 31, 2024, total unrecognized compensation cost related to unvested restricted stock units was $7.8 million, which is expected to be recognized over a weighted-average period of 2.34 years. Stock Options The following table summarizes the Company’s stock option activity: Number of Weighted Weighted Aggregate (In years) (In thousands) Outstanding as of December 31, 2023 666,163 $ 160.19 Granted 428,850 43.36 Exercised (3,634) 39.30 $ 38 Cancelled or Forfeited (7,353) 124.58 Outstanding as of March 31, 2024 1,084,026 $ 114.62 8.38 $ 14,197 Exercisable as of March 31, 2024 689,361 $ 129.09 8.06 $ 7,632 Vested and expected to vest as of March 31, 2024 1,084,026 $ 114.62 8.38 $ 14,197 Valuation of Stock Options The weighted-average assumptions that the Company used in the Black-Scholes option pricing model to determine the grant-date fair value of stock options granted to employees and non-employees on the date of grant were as follows for the three months ended March 31, 2024: Three Months Ended 2024 Risk-free interest rate 3.88 % Expected term (in years) 6.01 Expected volatility 88.75 % Expected dividend yield — % Weighted average grant-date fair value per share $ 32.70 As of March 31, 2024, total unrecognized compensation cost related to unvested stock options was $24.8 million, which is expected to be recognized over a weighted-average period of 1.88 years. Stock-Based Compensation Stock-based compensation expense was allocated as follows (in thousands): Three Months Ended 2024 2023 Research and development $ 5,598 $ 2,223 General and administrative 8,877 5,370 Total stock-based compensation expense $ 14,475 $ 7,593

Net Loss per Share

Net Loss per Share	3 Months Ended
	Mar. 31, 2024
Earnings Per Share [Abstract]
Net Loss per Share	Net Loss per Share The following potential common shares, presented based on amounts outstanding at each period end, were excluded from the calculation of diluted net loss per share attributable to common stockholders for the periods indicated because including them would have been anti-dilutive: Three Months Ended 2024 2023 Outstanding stock options 1,084,026 712,737 Unvested restricted stock units 97,601 50,317 Potential shares issuable under the 2020 ESPP 27,827 11,984 1,209,454 775,038 Common shares issuable upon exercise of the pre-funded warrants that were sold in connection with the June 2023 and the January 2024 underwritten public offering are included in the calculation of basic weighted average number of common shares outstanding for the three months ended March 31, 2024. Consistent with the guidance in ASC 260-10-45-13, the underlying common shares are issuable for little to no consideration and there are no vesting conditions or contingencies associated with the warrants. Accordingly, the aggregate number of common shares underlying the pre-funded warrants have been considered outstanding for purposes of the calculation of basic net loss per share from the date of issuance.

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2024
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions On September 11, 2019, the Company entered into a Cooperation and License Agreement (the “License Agreement”) with RogCon Inc. (“RogCon”). Under the License Agreement, RogCon granted to the Company an exclusive, worldwide license under RogCon's intellectual property to research, develop and commercialize products for the treatment of all forms of epilepsy and/or neurodevelopmental disorders in each case caused by any mutation of the SCN2A gene. Pursuant to the terms of the License Agreement, the Company will conduct, at its own cost and expense, the research and development activities assigned to it under the associated research plan. In addition, the Company is responsible for reimbursing RogCon for any costs associated with research and development activities RogCon performs at the request of the Company. One of the founders of RogCon became the Company's General Counsel in June 2020. The Company continues to reimburse RogCon for its out-of-pocket costs incurred for activities performed under the License Agreement. Expenses incurred during all periods presented were not material.

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2024
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events April 2024 Financing On April 2, 2024 the Company completed a public offering of: (i) an aggregate of 3,849,558 shares of its common stock at a public offering price of $56.50 per share, including the underwriters' full exercise of their option to purchase 530,973 additional shares of common stock, and (ii) pre-funded warrants to purchase 221,238 shares of common stock at a public offering price of $56.4999 per share of common stock underlying the warrants. The purchase price per share for each pre-funded warrant represents the per share offering price for the common stock, less the $0.0001 per share exercise price of each underlying share. Total net proceeds generated from the offering were approximately $215.8 million, after deducting underwriting discounts, commissions and other offering expenses payable by the Company.

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Pay vs Performance Disclosure
Net loss	$ (39,553)	$ (37,455)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Mar. 31, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2024
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying condensed consolidated financial statements have been prepared in conformity with generally accepted accounting principles 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 ASUs of the FASB. The significant accounting policies used in preparation of these condensed consolidated financial statements for the three months ended March 31, 2024 are consistent with those discussed in Note 2 to the consolidated financial statements included in the Company's 2023 Annual Report on Form 10-K, other than as noted below. Reverse Stock Split On November 28, 2023, the Company filed a Certificate of Amendment to the Company's Amended and Restated Certificate of Incorporation with the Secretary of State of the State of Delaware to effect a 1-for-15 reverse stock split of its common stock (the "Reverse Stock Split"). The Reverse Stock Split became effective at 5:00 p.m., Eastern Time, on November 28, 2023 (the "Effective Time"). As a result of the Reverse Stock Split, every 15 shares of the Company's issued and outstanding common stock were automatically reclassified into one validly issued, fully-paid and non-assessable share of common stock. Any fractional post-split shares as a result of the Reverse Stock Split were rounded down to the nearest whole post-split share. The Reverse Stock Split did not affect the number of authorized shares of common stock or the par value of the common stock. All share amounts and per share amounts for the periods prior to the Effective Time disclosed in this Quarterly Report on Form 10-Q have been restated to reflect the Reverse Stock Split on a retroactive basis. Marketable Securities Classification The Company may invest its excess cash in money market funds and debt instruments of the U.S. Treasury, financial institutions, corporations and U.S. government agencies with strong credit ratings and an investment grade rating at or above A-1 or P-1 by two of the three nationally recognized statistical rating organizations. The Company does not believe that it is exposed to more than a nominal amount of credit risk related to any marketable securities it may invest in. The Company has established guidelines relative to diversification and maturities that maintain safety and liquidity, and periodically reviews and modifies these guidelines to maximize trends in yields and interest rates without compromising safety and liquidity. The Company classifies its investments in debt instruments as available-for-sale. Available-for-sale investments are reported at fair value at each balance sheet date, and include any unrealized holding gains and losses in accumulated other comprehensive loss, a component of stockholders’ equity. Realized gains and losses are included in the Company's condensed consolidated statements of operations. All of the Company's available-for-sale securities are available for use in its current operations. The Company classifies marketable securities as either cash equivalents, short-term, or long-term based on their stated maturity dates as it is more-likely-than-not that the Company will hold these assets through to their maturity dates.
Unaudited Interim Condensed Consolidated Financial Information	Unaudited Interim Condensed Consolidated Financial Information The accompanying condensed consolidated balance sheet as of March 31, 2024, the condensed consolidated statements of operations for the three months ended March 31, 2024 and 2023, the condensed consolidated statements of comprehensive loss for the three months ended March 31, 2024 and 2023, the condensed consolidated statements of cash flows for the three months ended March 31, 2024 and 2023 and the condensed consolidated statements of stockholders’ equity for the three months ended March 31, 2024 and 2023 are unaudited. The unaudited interim financial statements have been prepared on the same basis as the audited annual consolidated financial statements, and in the opinion of management reflect all adjustments, which include only normal recurring adjustments necessary for the fair statement of the Company’s financial position as of March 31, 2024, the results of its operations for the three months ended March 31, 2024 and 2023 and its cash flows for the three months ended March 31, 2024 and 2023. Financial statement disclosures for the three months ended March 31, 2024 and 2023 are condensed and do not include all disclosures required for an annual set of financial statements in accordance with GAAP. The results for the three months ended March 31, 2024 are not necessarily indicative of results to be expected for the year ended December 31, 2024, any other interim periods, or any future year or period.
Use of Estimates	Use of Estimates The preparation of condensed 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 condensed consolidated financial statements and the reported amounts of expenses during the reporting periods. Significant estimates and assumptions reflected in these condensed consolidated financial statements include, but are not limited to, accrued and prepaid research and development expense, collaboration revenue, stock-based compensation expense and the recoverability of the Company’s net deferred tax assets and related valuation allowance. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Changes in estimates are recorded in the period in which they become known. Actual results could differ materially from those estimates.
Common Stock Warrants	Common Stock Warrants The Company accounts for warrants to purchase shares of its common stock in accordance with the guidance in FASB ASC No. 480, Distinguishing Liabilities from Equity (ASC 480) and ASC No. 815, Derivatives and Hedging (ASC 815). The Company classifies warrants issued for the purchase of shares of its common stock as either equity or liability instruments based on an assessment of the specific terms and conditions of each respective contract. Such assessment includes determining whether the warrants are freestanding financial instruments or embedded in a host instrument, whether the warrants are liabilities within the scope of ASC 480, whether the warrants meet the definition of a derivative in ASC 815 and whether the warrants meet the requirements for equity classification pursuant to the indexation and equity classification criteria in ASC 815. The Company determines the classification for its warrants at the time of issuance and updates its assessment, as necessary. Warrants that meet all of the criteria for equity classification are recorded as a component of additional paid-in capital.
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 for the period. The calculation of weighted average number of common shares outstanding excludes shares of restricted common stock that are not vested but includes shares of common stock underlying pre-funded warrants. Diluted net loss per share is computed by dividing net loss by the weighted average number of common shares outstanding for the period, after giving consideration to the dilutive effect of potentially dilutive common shares. For purposes of this calculation, outstanding options to purchase shares of common stock, unvested shares of restricted common stock and potential shares issuable under the 2020 ESPP are considered potentially dilutive common shares. The Company has generated a net loss in all periods presented so the basic and diluted net loss per share are the same, as the inclusion of the potentially dilutive securities would be anti-dilutive.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Recently Issued Accounting Pronouncements On November 27, 2023, the FASB issued ASU No. 2023-07, Segment Reporting (Topic 280) - Improvements to Reportable Segment Disclosures . ASU No. 2023-07 improves reportable segment disclosure requirements, primarily through enhanced disclosures about significant segment expenses. The amendments included in this ASU apply to all public entities that are required to report segment information in accordance with Topic 280, including those with a single reportable segment. The amendments are effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024. Early adoption is permitted and should be applied retrospectively to all prior periods presented in the financial statements. Upon transition, the segment expenses categories and amounts disclosed in the prior periods should be based on the significant segment expense categories identified and disclosed in the period of adoption. The Company only has one reportable segment and this ASU impacts disclosures only. The Company has determined that the effects of adopting the amendments in ASU 2023-07 will only impact its disclosures and not have a material impact on its consolidated financial position and the results of its operations when such amendment is adopted. On December 14, 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740) - Improvements to Income Tax Disclosures . ASU No. 2023-09 provides more transparency about income tax information through improvements to income tax disclosures primarily related to the rate reconciliation and incomes taxes paid information. For public companies, the amendments are effective for annual periods beginning after December 15, 2024 and should be applied prospectively. The Company has determined that the effects of adopting the amendments in ASU 2023-09 will only impact its disclosures and will not have a material impact on its consolidated financial position and the results of its operations when such amendment is adopted.

Cash Equivalents and Marketab_2

Cash Equivalents and Marketable Securities (Tables)	3 Months Ended
	Mar. 31, 2024
Investments, Debt and Equity Securities [Abstract]
Debt Securities, Available-for-Sale	The following is a summary of the Company's investment portfolio as of March 31, 2024. The Company did not hold any cash equivalents or marketable securities as of December 31, 2023 (in thousands): As of March 31, 2024 Gross Unrealized Estimated Cost Gains Losses Fair Value Cash equivalents: Money market funds $ 15,971 $ — $ — $ 15,971 Debt securities issued by U.S. government agencies 17,889 — — 17,889 Corporate debt securities 12,009 — (1) 12,008 Commercial paper 2,450 — (1) 2,449 Available-for-sale marketable securities: Debt securities issued by U.S. government agencies 59,722 12 — 59,734 Corporate debt securities 26,602 — (2) 26,600 Commercial paper 1,934 — (3) 1,931 Other debt securities 3,046 — (2) 3,044 Total cash equivalents and marketable securities $ 139,623 $ 12 $ (9) $ 139,626 Contractual maturities of the marketable securities at each balance sheet date are as follows (in thousands): March 31, 2024 December 31, 2023 Within one year $ 87,782 $ — After one year through five years 35,873 — Total $ 123,655 $ —

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2024
Fair Value Disclosures [Abstract]
Summary of Financial Assets Measured At Fair Value On A Recurring Basis	The following table presents information about the Company’s financial assets measured at fair value on a recurring basis and indicates the level of the fair value hierarchy utilized to determine such fair values as of March 31, 2024 (in thousands). The Company did not hold any financial assets measured at fair value on a recurring basis as of December 31, 2023: As of March 31, 2024 Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 15,971 $ — $ — $ 15,971 Debt securities issued by U.S. government agencies 17,889 — — 17,889 Corporate debt securities — 12,008 — 12,008 Commercial paper — 2,449 — 2,449 Available-for-sale marketable securities: Debt securities issued by U.S. government agencies 59,734 — — 59,734 Corporate debt securities — 26,600 — 26,600 Commercial paper — 1,931 — 1,931 Other debt securities — 3,044 — 3,044 $ 93,594 $ 46,032 $ — $ 139,626

Accrued Expenses (Tables)

Accrued Expenses (Tables)	3 Months Ended
	Mar. 31, 2024
Payables and Accruals [Abstract]
Summary of Accrued Expenses	Accrued expenses consisted of the following (in thousands): March 31, 2024 December 31, 2023 Accrued external research and development expenses $ 4,717 $ 2,957 Accrued personnel-related expenses 1,661 3,716 Accrued other expenses 598 743 Total accrued expenses $ 6,976 $ 7,416

Common Stock and Preferred St_2

Common Stock and Preferred Stock (Tables)	3 Months Ended
	Mar. 31, 2024
Stockholders' Equity Note [Abstract]
Summary of Common Stock Reserved For Future Issuance	The Company has reserved the following shares of common stock for future issuance: March 31, December 31, Shares reserved for exercise of outstanding stock options 1,084,026 666,163 Shares reserved for exercise of pre-funded warrants related to the June 2023 Financing 470,000 470,000 Shares reserved for exercise of pre-funded warrants related to the January 2024 Financing 1,056,725 — Shares reserved for future awards under the 2020 Stock Option and Incentive Plan 111,028 148,264 Shares reserved for future awards under the 2020 Employee Stock Purchase Plan 141,029 53,111 Shares reserved for future awards under the 2024 Inducement Plan 996,950 — Shares reserved for vesting of restricted stock units 97,601 47,145 Total shares of authorized common stock reserved for future issuance 3,957,359 1,384,683

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2024
Share-Based Payment Arrangement [Abstract]
Summary of Restricted Stock Activity	The following table summarizes the Company’s restricted stock unit activity: Shares Weighted Unvested as of December 31, 2023 47,145 $ 202.27 Issued 65,333 43.35 Vested (11,346) 316.60 Forfeited (3,531) 35.63 Unvested as of March 31, 2024 97,601 $ 88.63
Summary of Stock Option Activity	The following table summarizes the Company’s stock option activity: Number of Weighted Weighted Aggregate (In years) (In thousands) Outstanding as of December 31, 2023 666,163 $ 160.19 Granted 428,850 43.36 Exercised (3,634) 39.30 $ 38 Cancelled or Forfeited (7,353) 124.58 Outstanding as of March 31, 2024 1,084,026 $ 114.62 8.38 $ 14,197 Exercisable as of March 31, 2024 689,361 $ 129.09 8.06 $ 7,632 Vested and expected to vest as of March 31, 2024 1,084,026 $ 114.62 8.38 $ 14,197
Schedule of Fair Value of Stock Option Awards on the Grant Date Using the Black-Scholes Option Valuation Model	The weighted-average assumptions that the Company used in the Black-Scholes option pricing model to determine the grant-date fair value of stock options granted to employees and non-employees on the date of grant were as follows for the three months ended March 31, 2024: Three Months Ended 2024 Risk-free interest rate 3.88 % Expected term (in years) 6.01 Expected volatility 88.75 % Expected dividend yield — % Weighted average grant-date fair value per share $ 32.70
Summary of Stock-Based Compensation Expense	Stock-based compensation expense was allocated as follows (in thousands): Three Months Ended 2024 2023 Research and development $ 5,598 $ 2,223 General and administrative 8,877 5,370 Total stock-based compensation expense $ 14,475 $ 7,593

Net Loss per Share (Tables)

Net Loss per Share (Tables)	3 Months Ended
	Mar. 31, 2024
Earnings Per Share [Abstract]
Summary of Antidilutive Securities Excluded From Computation of Earnings Per Share	The following potential common shares, presented based on amounts outstanding at each period end, were excluded from the calculation of diluted net loss per share attributable to common stockholders for the periods indicated because including them would have been anti-dilutive: Three Months Ended 2024 2023 Outstanding stock options 1,084,026 712,737 Unvested restricted stock units 97,601 50,317 Potential shares issuable under the 2020 ESPP 27,827 11,984 1,209,454 775,038

Nature of the Business - Additi

Nature of the Business - Additional Information (Details) $ in Thousands				1 Months Ended	3 Months Ended
	Apr. 02, 2024 USD ($)	Jan. 16, 2024 USD ($)	Jun. 21, 2023 USD ($)	Apr. 30, 2024 USD ($)	Mar. 31, 2024 USD ($) platform candidate	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)
Cash and Cash Equivalents [Line Items]
Number of platforms | platform					2
Number of product candidates | candidate					4
Proceeds from issuance or sale of equity					$ 785,300
Net loss					39,553	$ 37,455
Accumulated deficit					693,474		$ 653,921
Cash, cash equivalents, and marketable securities					243,300
Follow-On Offering
Cash and Cash Equivalents [Line Items]
Proceeds from stock offerings, net of issuance costs		$ 161,600	$ 63,400		$ 161,649	$ 0
Subsequent Event | Follow-On Offering
Cash and Cash Equivalents [Line Items]
Proceeds from stock offerings, net of issuance costs	$ 215,800			$ 215,800

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details)		3 Months Ended
	Nov. 28, 2023	Mar. 31, 2024 segment
Accounting Policies [Abstract]
Stockholders' equity note, stock split, conversion ratio	0.0667
Number of reportable segments		1

Cash Equivalents and Marketab_3

Cash Equivalents and Marketable Securities - Investment Profile (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, current	$ 55,436	$ 0
Cash equivalents, at carrying value and debt securities, available-for-sale, amortized cost	139,623
Cash equivalents and debt securities, available-for-sale, accumulated gross unrealized gain, current, before tax	12
Cash equivalents and debt securities, available-for-sale, accumulated gross unrealized loss, current, before tax	(9)
Cash equivalents and debt securities, available-for-sale, fair value disclosure	139,626
Money market funds
Debt Securities, Available-for-sale [Line Items]
Cash equivalents, at carrying value	15,971
Cash equivalents, accumulated gross unrealized gain, current, before tax	0
Cash equivalents, accumulated gross unrealized loss, current, before tax	0
Cash equivalents, fair value disclosure	15,971
Debt securities issued by U.S. government agencies
Debt Securities, Available-for-sale [Line Items]
Cash equivalents, at carrying value	17,889
Cash equivalents, accumulated gross unrealized gain, current, before tax	0
Cash equivalents, accumulated gross unrealized loss, current, before tax	0
Cash equivalents, fair value disclosure	17,889
Debt securities, available-for-sale, amortized cost, current	59,722
Debt securities, available-for-sale, accumulated gross unrealized gain, current, before tax	12
Debt securities, available-for-sale, accumulated gross unrealized loss, current, before tax	0
Debt securities, available-for-sale, current	59,734
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Cash equivalents, at carrying value	12,009
Cash equivalents, accumulated gross unrealized gain, current, before tax	0
Cash equivalents, accumulated gross unrealized loss, current, before tax	(1)
Cash equivalents, fair value disclosure	12,008
Debt securities, available-for-sale, amortized cost, current	26,602
Debt securities, available-for-sale, accumulated gross unrealized gain, current, before tax	0
Debt securities, available-for-sale, accumulated gross unrealized loss, current, before tax	(2)
Debt securities, available-for-sale, current	26,600
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Cash equivalents, at carrying value	2,450
Cash equivalents, accumulated gross unrealized gain, current, before tax	0
Cash equivalents, accumulated gross unrealized loss, current, before tax	(1)
Cash equivalents, fair value disclosure	2,449
Debt securities, available-for-sale, amortized cost, current	1,934
Debt securities, available-for-sale, accumulated gross unrealized gain, current, before tax	0
Debt securities, available-for-sale, accumulated gross unrealized loss, current, before tax	(3)
Debt securities, available-for-sale, current	1,931
Other debt securities
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, amortized cost, current	3,046
Debt securities, available-for-sale, accumulated gross unrealized gain, current, before tax	0
Debt securities, available-for-sale, accumulated gross unrealized loss, current, before tax	(2)
Debt securities, available-for-sale, current	$ 3,044

Cash Equivalents and Marketab_4

Cash Equivalents and Marketable Securities - Narrative (Details)	3 Months Ended
	Mar. 31, 2024 USD ($) security	Mar. 31, 2023 USD ($)
Investments, Debt and Equity Securities [Abstract]
Number of securities | security	33
Securities, unrealized loss position, fair value	$ 42,600,000
Other-than-temporary impairment loss, debt securities, available-for-sale	$ 0	$ 0

Cash Equivalents and Marketab_5

Cash Equivalents and Marketable Securities - Contractual Maturity of Marketable Securities (Details) - USD ($)	Mar. 31, 2024	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Within one year	$ 87,782,000	$ 0
After one year through five years	35,873,000	0
Total available-for-sale securities	$ 123,655,000	$ 0

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Financial Assets Measured at Fair Value on a Recurring Basis (Details) - Fair Value, Recurring - USD ($)	Mar. 31, 2024	Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	$ 139,626,000	$ 0
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	93,594,000
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	46,032,000
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0
Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	15,971,000
Money market funds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	15,971,000
Money market funds | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0
Money market funds | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0
Debt securities issued by U.S. government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	17,889,000
Available-for-sale marketable securities	59,734,000
Debt securities issued by U.S. government agencies | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	17,889,000
Available-for-sale marketable securities	59,734,000
Debt securities issued by U.S. government agencies | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0
Available-for-sale marketable securities	0
Debt securities issued by U.S. government agencies | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0
Available-for-sale marketable securities	0
Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	12,008,000
Available-for-sale marketable securities	26,600,000
Corporate debt securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0
Available-for-sale marketable securities	0
Corporate debt securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	12,008,000
Available-for-sale marketable securities	26,600,000
Corporate debt securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0
Available-for-sale marketable securities	0
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	2,449,000
Available-for-sale marketable securities	1,931,000
Commercial paper | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0
Available-for-sale marketable securities	0
Commercial paper | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	2,449,000
Available-for-sale marketable securities	1,931,000
Commercial paper | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0
Available-for-sale marketable securities	0
Other debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale marketable securities	3,044,000
Other debt securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale marketable securities	0
Other debt securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale marketable securities	3,044,000
Other debt securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale marketable securities	$ 0

Accrued Expenses - Summary of A

Accrued Expenses - Summary of Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Payables and Accruals [Abstract]
Accrued external research and development expenses	$ 4,717	$ 2,957
Accrued personnel-related expenses	1,661	3,716
Accrued other expenses	598	743
Total accrued expenses	$ 6,976	$ 7,416

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details)	May 31, 2021
Office Space in Boston Massachusetts
Loss Contingencies [Line Items]
Percentage increase in annual base rent	2%

Collaboration License Agreeme_2

Collaboration License Agreements - Narrative (Details) $ / shares in Units, $ in Thousands		1 Months Ended	3 Months Ended
	Jan. 04, 2024 USD ($) obligation $ / shares shares	Jan. 31, 2024 USD ($)	Mar. 31, 2024 USD ($) $ / shares	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($) obligation
Disaggregation of Revenue [Line Items]
Number of performance obligations | obligation	1					1
Collaboration revenue			$ 431	$ 683
Current portion of deferred revenue			1,256		$ 1,392
UCB | License
Disaggregation of Revenue [Line Items]
Upfront payment			2,100			$ 5,000
Milestone payments						98,500
Transaction price						$ 5,000
Collaboration revenue			400
Current portion of deferred revenue			$ 1,300
Tenacia
Disaggregation of Revenue [Line Items]
Number of shares issued in transaction (in shares) | shares	443,253
Sale of stock (in USD per share) | $ / shares	$ 22.5605		$ 38.95
Proceeds from stock offerings, net of issuance costs	$ 10,000	$ 10,000
Sale of stock, volume-weighted average price, premium	20%		20%
Sale of stock, volume-weighted average price, duration	30 days		30 days
Proceeds from collaboration arrangement		14,800
Sale of stock, value transferred			$ 17,300
Sale of stock, value transferred in excess of consideration received			$ 2,500
Tenacia | License
Disaggregation of Revenue [Line Items]
Upfront payment	$ 5,000	$ 4,800
Milestone payments	$ 264,000

Common Stock and Preferred St_3

Common Stock and Preferred Stock - Additional Information (Details) $ / shares in Units, $ in Thousands				3 Months Ended
	Jan. 16, 2024 USD ($) $ / shares shares	Nov. 28, 2023	Jun. 21, 2023 USD ($) $ / shares shares	Mar. 31, 2024 USD ($) $ / shares shares	Mar. 31, 2023 USD ($)	Dec. 31, 2023 $ / shares shares
Schedule Of Common Stock Reserved For Future Issuance [Line Items]
Stockholders' equity note, stock split, conversion ratio		0.0667
Common stock, authorized (in shares)				150,000,000		150,000,000
Common stock, par value (in dollars per share) | $ / shares				$ 0.0001		$ 0.0001
Treasury stock (in shares)				0		0
Preferred stock, authorized (in shares)				10,000,000		10,000,000
Preferred stock, par value (in dollars per share) | $ / shares				$ 0.0001		$ 0.0001
Pre-Funded Warrant | Maximum
Schedule Of Common Stock Reserved For Future Issuance [Line Items]
Maximum percentage of voting power				4.99%
Percentage of ownership held by sole owner and affiliates				9.99%
Percentage change in ownership				19.99%
Warrant
Schedule Of Common Stock Reserved For Future Issuance [Line Items]
Change in ownership notice, term				61 days
Follow-On Offering
Schedule Of Common Stock Reserved For Future Issuance [Line Items]
Common stock, authorized (in shares)			4,296,646
Sale of stock (in USD per share) | $ / shares	$ 35.50		$ 14.25
Proceeds from stock offerings, net of issuance costs | $	$ 161,600		$ 63,400	$ 161,649	$ 0
Sale of stock, shares, aggregate authorized amount (in shares)	3,802,025
Follow-On Offering | Pre-Funded Warrant
Schedule Of Common Stock Reserved For Future Issuance [Line Items]
Sale of stock (in USD per share) | $ / shares	$ 35.4999		$ 14.2485
Warrants (in shares)	1,056,725		470,000
Follow-On Offering | Warrant
Schedule Of Common Stock Reserved For Future Issuance [Line Items]
Warrants (in dollars per share) | $ / shares	$ 0.0001		$ 0.0015
Over-Allotment Option
Schedule Of Common Stock Reserved For Future Issuance [Line Items]
Number of shares issued in transaction (in shares)	633,750		619,979

Common Stock and Preferred St_4

Common Stock and Preferred Stock - Summary of Common Stock Reserved For Future Issuance (Details) - shares	Mar. 31, 2024	Dec. 31, 2023
Schedule Of Common Stock Reserved For Future Issuance [Line Items]
Total shares of authorized common stock reserved for future issuance (in shares)	3,957,359	1,384,683
Shares reserved for exercise of outstanding stock options
Schedule Of Common Stock Reserved For Future Issuance [Line Items]
Total shares of authorized common stock reserved for future issuance (in shares)	1,084,026	666,163
Pre-Funded Warrant | June 2023 Follow-On Offering
Schedule Of Common Stock Reserved For Future Issuance [Line Items]
Total shares of authorized common stock reserved for future issuance (in shares)	470,000	470,000
Pre-Funded Warrant | January 2024 Follow-On Offering
Schedule Of Common Stock Reserved For Future Issuance [Line Items]
Total shares of authorized common stock reserved for future issuance (in shares)	1,056,725	0
Share-based payment arrangement | Shares reserved for future awards under the 2020 Stock Option and Incentive Plan
Schedule Of Common Stock Reserved For Future Issuance [Line Items]
Total shares of authorized common stock reserved for future issuance (in shares)	111,028	148,264
Share-based payment arrangement | Shares reserved for future awards under the 2020 Employee Stock Purchase Plan
Schedule Of Common Stock Reserved For Future Issuance [Line Items]
Total shares of authorized common stock reserved for future issuance (in shares)	141,029	53,111
Share-based payment arrangement | Shares reserved for future awards under the 2024 Inducement Plan
Schedule Of Common Stock Reserved For Future Issuance [Line Items]
Total shares of authorized common stock reserved for future issuance (in shares)	996,950	0
Shares reserved for vesting of restricted stock units
Schedule Of Common Stock Reserved For Future Issuance [Line Items]
Total shares of authorized common stock reserved for future issuance (in shares)	97,601	47,145

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Unvested Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation cost related to unvested restricted stock units	$ 7.8
Weighted-average period (in years)	2 years 4 months 2 days
Shares reserved for exercise of outstanding stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average period (in years)	1 year 10 months 17 days
Unrecognized compensation expense related to unvested stock based awards	$ 24.8
Inducement Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)	1,000,000
2020 Employee Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)	1,100,833	661,240
2017 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)	395,850	395,850
2020 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)	175,145	87,227

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Restricted Stock Activity (Details) - Unvested restricted stock units	3 Months Ended
	Mar. 31, 2024 $ / shares shares
Shares
Beginning balance (in shares) | shares	47,145
Issued (in shares) | shares	65,333
Vested (in shares) | shares	(11,346)
Forfeited (in shares) | shares	(3,531)
Ending balance (in shares) | shares	97,601
Weighted Average Grant Date Fair Value
Unvested beginning balance (in dollars per share) | $ / shares	$ 202.27
Issued (in dollars per share) | $ / shares	43.35
Vested (in dollars per share) | $ / shares	316.60
Forfeitures (in dollars per shares) | $ / shares	35.63
Unvested ending balance (in dollars per share) | $ / shares	$ 88.63

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Stock Option Activity (Details) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($) $ / shares shares
Number of Shares
Beginning balance (in shares) | shares	666,163
Granted (in shares) | shares	428,850
Exercised (in shares) | shares	(3,634)
Canceled or forfeited (in shares) | shares	(7,353)
Ending balance (in shares) | shares	1,084,026
Number of shares exercisable (in shares) | shares	689,361
Vested and expected to vest (in shares) | shares	1,084,026
Weighted Average Exercise Price per Share
Beginning balance (in dollars per share) | $ / shares	$ 160.19
Granted (in dollars per share) | $ / shares	43.36
Exercised (in dollars per share) | $ / shares	39.30
Cancelled or forfeited (in dollars per share) | $ / shares	124.58
Ending balance (in dollars per share) | $ / shares	114.62
Exercisable (in dollars per share) | $ / shares	129.09
Vested and expected to vest (in dollars per share) | $ / shares	$ 114.62
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted average remaining contractual term outstanding	8 years 4 months 17 days
Weighted average remaining contractual term exercisable	8 years 21 days
Weighted average remaining contractual term vested and expected to vest	8 years 4 months 17 days
Aggregate intrinsic value exercised | $	$ 38
Aggregate intrinsic value outstanding | $	14,197
Aggregate intrinsic value exercisable | $	7,632
Aggregate intrinsic value vested and expected to vest | $	$ 14,197

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Fair Value of Stock Option Awards on the Grant Date Using the Black-Scholes Option Valuation Model (Details)	3 Months Ended
	Mar. 31, 2024 $ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	3.88%
Expected term (in years)	6 years 3 days
Expected volatility	88.75%
Expected dividend yield	0%
Shares reserved for exercise of outstanding stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant-date fair value per share (in dollars per share)	$ 32.70

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	$ 14,475	$ 7,593
Research and development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	5,598	2,223
General and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	$ 8,877	$ 5,370

Net Loss per Share - Summary of

Net Loss per Share - Summary of antidilutive securities excluded from computation of earnings per share (Details) - shares	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	1,209,454	775,038
Outstanding stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	1,084,026	712,737
Unvested restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	97,601	50,317
Potential shares issuable under the 2020 ESPP
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	27,827	11,984

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Thousands				1 Months Ended	3 Months Ended
	Apr. 02, 2024	Jan. 16, 2024	Jun. 21, 2023	Apr. 30, 2024	Mar. 31, 2024	Mar. 31, 2023
Follow-On Offering
Subsequent Event [Line Items]
Sale of stock, shares, aggregate authorized amount (in shares)		3,802,025
Sale of stock (in USD per share)		$ 35.50	$ 14.25
Proceeds from stock offerings, net of issuance costs		$ 161,600	$ 63,400		$ 161,649	$ 0
Follow-On Offering | Pre-Funded Warrant
Subsequent Event [Line Items]
Sale of stock (in USD per share)		$ 35.4999	$ 14.2485
Warrants (in shares)		1,056,725	470,000
Follow-On Offering | Warrant
Subsequent Event [Line Items]
Warrants (in dollars per share)		$ 0.0001	$ 0.0015
Over-Allotment Option
Subsequent Event [Line Items]
Number of shares issued in transaction (in shares)		633,750	619,979
Subsequent Event | Follow-On Offering
Subsequent Event [Line Items]
Sale of stock, shares, aggregate authorized amount (in shares)	3,849,558
Sale of stock (in USD per share)	$ 56.50
Proceeds from stock offerings, net of issuance costs	$ 215,800			$ 215,800
Subsequent Event | Follow-On Offering | Pre-Funded Warrant
Subsequent Event [Line Items]
Sale of stock (in USD per share)	$ 56.4999
Warrants (in shares)	221,238
Subsequent Event | Follow-On Offering | Warrant
Subsequent Event [Line Items]
Warrants (in dollars per share)	$ 0.0001
Subsequent Event | Over-Allotment Option
Subsequent Event [Line Items]
Number of shares issued in transaction (in shares)	530,973