Solid Biosciences (SLDB) 10-Q 15 May 24 2024 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2024	May 10, 2024
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2024
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1
Trading Symbol	SLDB
Entity Registrant Name	Solid Biosciences Inc.
Entity Current Reporting Status	Yes
Entity Central Index Key	0001707502
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		38,379,413
Entity File Number	001-38360
Entity Tax Identification Number	90-0943402
Entity Address, Address Line One	500 Rutherford Avenue
Entity Address, City or Town	Third FloorCharlestown
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02129
City Area Code	617
Local Phone Number	337-4680
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock $0.001 par value per share
Security Exchange Name	NASDAQ
Entity Incorporation, State or Country Code	DE
Document Quarterly Report	true
Document Transition Report	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 117,574	$ 74,015
Available-for-sale securities	88,492	49,625
Prepaid expenses and other current assets	8,126	6,094
Total current assets	214,192	129,734
Operating lease, right-of-use assets	26,098	26,539
Property and equipment, net	6,391	6,624
Other non-current assets	175	209
Restricted cash	1,833	1,833
Total assets	248,689	164,939
Current liabilities:
Accounts payable	1,730	2,032
Accrued expenses	10,327	10,137
Operating lease liabilities	1,694	1,855
Finance lease liabilities	496	469
Other current liabilities	92	24
Total current liabilities	14,339	14,517
Operating lease liabilities, excluding current portion	22,526	22,707
Finance lease liabilities, excluding current portion	1,100	1,234
Total liabilities	37,965	38,458
Commitments and contingencies (Note 11)
Preferred stock, $0.001 par value - 10,000,000 shares authorized; no shares issued and outstanding at March 31, 2024 and December 31, 2023
Common stock, $0.001 par value - 60,000,000 shares authorized; 37,833,689 and 20,386,606 shares issued and outstanding at March 31, 2024 and December 31, 2023, respectively	38	20
Additional paid-in capital	893,746	785,199
Accumulated other comprehensive (loss) income	(4)	15
Accumulated deficit	(683,056)	(658,753)
Total stockholders’ equity	210,724	126,481
Total liabilities and stockholders’ equity	$ 248,689	$ 164,939

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	60,000,000	60,000,000
Common stock, shares issued	37,833,689	20,386,606
Common stock, shares outstanding	37,833,689	20,386,606

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Operating expenses:
Research and development	$ 18,873	$ 24,631
General and administrative	7,989	7,399
Total operating expenses	26,862	32,030
Loss from operations	(26,862)	(32,030)
Other income, net:
Interest income	2,651	1,799
Interest expense	(95)	(121)
Other income, net	3	282
Total other income, net	2,559	1,960
Net loss	$ (24,303)	$ (30,070)
Net loss per share, basic	$ (0.64)	$ (1.54)
Net loss per share, diluted	$ (0.64)	$ (1.54)
Weighted average shares of common stock outstanding, basic	38,155,373	19,567,635
Weighted average shares of common stock outstanding, diluted	38,155,373	19,567,635

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Statement of Comprehensive Income [Abstract]
Net loss	$ (24,303)	$ (30,070)
Other comprehensive (loss) income:
Unrealized (loss) gain on available-for-sale securities	(19)	73
Comprehensive loss	$ (24,322)	$ (29,997)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Private Placement [Member]	Common Stock [Member]	Common Stock [Member] Private Placement [Member]	Additional Paid in Capital [Member]	Additional Paid in Capital [Member] Private Placement [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]
Beginning balance at Dec. 31, 2022	$ 211,666		$ 20		$ 774,452		$ (68)	$ (562,738)
Beginning balance, units at Dec. 31, 2022			19,556,732
Equity-based compensation	2,118				2,118
Vesting of restricted stock, units			16,400
Unrealized gain (loss) on available-for-sale securities	73						73
Net loss	(30,070)							(30,070)
Ending balance at Mar. 31, 2023	183,787		$ 20		776,570		5	(592,808)
Ending balance, units at Mar. 31, 2023			19,573,132
Beginning balance at Dec. 31, 2023	126,481		$ 20		785,199		15	(658,753)
Beginning balance, units at Dec. 31, 2023			20,386,606
Equity-based compensation	1,611				1,611
Issuance of common stock, net of issuance costs	3,056	$ 89,454	$ 1	$ 17	3,055	$ 89,437
Issuance of common stock, net of issuance costs, units			350,664	16,973,103
Issuance of pre-funded warrants in private placement	14,293				14,293
Vesting of restricted stock, units			98,677
Exercise of common stock options	151				151
Exercise of common stock options, units			24,639
Unrealized gain (loss) on available-for-sale securities	(19)						(19)
Net loss	(24,303)							(24,303)
Ending balance at Mar. 31, 2024	$ 210,724		$ 38		$ 893,746		$ (4)	$ (683,056)
Ending balance, units at Mar. 31, 2024			37,833,689

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($)
Statement of Stockholders' Equity [Abstract]
Issuance costs	$ 4,407
Pre-funded warrants issuance costs	704
Sales commissions	$ 78

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash flows from operating activities:
Net loss	$ (24,303)	$ (30,070)
Adjustments to reconcile net loss to net cash used in operating activities:
Amortization of discount on available-for-sale securities	(540)	(215)
Equity-based compensation expense	1,611	2,118
Depreciation, impairment, and amortization expense	327	1,077
Gain on termination of lease	(89)
Other	(5)
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(1,337)	1,261
Accounts payable	(596)	2,745
Accrued expenses and other liabilities	(260)	(4,911)
Net cash used in operating activities	(25,192)	(27,995)
Cash flows from investing activities:
Purchases of property and equipment	(149)	(506)
Proceeds from maturities of available-for-sale securities	45,000	37,766
Purchases of available-for-sale securities	(83,346)
Other	5
Net cash (used in) provided by investing activities	(38,490)	37,260
Cash flows from financing activities:
Proceeds from issuance of common stock and pre-funded warrants in private placement	108,859
Payments of common stock issuance costs	(4,825)
Proceeds from issuance of common stock in public offering, net of sales commissions	3,056
Proceeds from exercises of common stock options	151
Net cash provided by financing activities	107,241
Net increase in cash, cash equivalents, and restricted cash	43,559	9,265
Cash, cash equivalents, and restricted cash at beginning of period	75,848	157,217
Cash, cash equivalents, and restricted cash at end of period	119,407	$ 166,482
Supplemental disclosure of non-cash investing and financing activities:
Right-of-use assets acquired through operating leases	417
Decrease in right-of-use assets due to lease termination	(197)
Property and equipment purchases included in accounts payable and accrued expenses	$ 20

Condensed Consolidated Statem_6

Condensed Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Statement of Cash Flows [Abstract]
Cash and cash equivalents	$ 117,574	$ 74,015	$ 164,649
Restricted cash, non-current	1,833	1,833	1,833
Cash and cash equivalents and restricted cash as presented on the cash flow statement	$ 119,407	$ 75,848	$ 166,482	$ 157,217

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

Nature of the Business and Basi

Nature of the Business and Basis of Presentation	3 Months Ended
	Mar. 31, 2024
Accounting Policies [Abstract]
Nature of the Business and Basis of Presentation	1. Nature of the Business and Basis of Presentation Nature of Business Solid Biosciences Inc. was organized in March 2013 under the name SOLID Ventures Management, LLC and operated as a Delaware limited liability company until immediately prior to the effectiveness of its registration statement on Form S-1 on January 25, 2018, at which time it completed a statutory corporate conversion into a Delaware corporation and changed its name to Solid Biosciences Inc. (the “Company”). On December 2, 2022, the Company completed its acquisition of AavantiBio, Inc. (“AavantiBio”), a privately held gene therapy company focused on transforming the lives of patients with Friedreich’s ataxia (“FA”) and rare cardiomyopathies (the “Acquisition”). Upon the consummation of the Acquisition, the Company acquired AavantiBio’s gene therapy programs, AVB‑202‑TT for FA and AVB‑401 for BAG3 mediated dilated cardiomyopathy, as well as additional assets for the treatment of other cardiac diseases, platform technologies and know-how related thereto. AavantiBio is a wholly owned subsidiary of the Company. The Company is a life sciences company focused on advancing a portfolio of current and future gene therapy candidates (collectively, “Candidates”), including SGT-003 for the treatment of Duchenne muscular dystrophy (“Duchenne”), SGT-501 for the treatment of catecholaminergic polymorphic ventricular tachycardia ("CPVT"), and additional assets for the treatment of cardiac and other diseases, at different stages of development with varying levels of investment. The Company is advancing its diverse pipeline across rare neuromuscular and cardiac diseases, bringing together experts in science, technology, disease management and care. Patient-focused and founded by those directly impacted by Duchenne, the Company’s mission is to improve the daily lives of patients living with these devastating diseases. The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry, including, but not limited to, development by competitors of new technological innovations, dependence on licenses, protection of proprietary technology, dependence on key personnel, compliance with government regulations and the need to obtain additional financing to fund operations. Product candidates currently under development will require significant additional research and development efforts, including extensive preclinical studies and clinical trials and regulatory approval, prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel infrastructure and extensive compliance and reporting capabilities. The Company’s candidates are in development. There can be no assurance that the Company’s research and development will be successfully completed, that adequate protection for the Company’s intellectual property will be obtained, that any products developed will obtain necessary government regulatory approval or that any approved products will be commercially viable. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will generate significant revenue from product sales. The Company operates in an environment of rapid change in technology and substantial competition from, among others, other pharmaceutical and biotechnology companies. In addition, the Company is dependent upon the services of its employees, partners, and consultants. Liquidity The accompanying condensed consolidated financial statements have been prepared on a basis that assumes the Company will continue as a going concern and which contemplates the realization of assets and satisfaction of liabilities and commitments in the ordinary course of business. Through March 31, 2024, the Company has funded its operations primarily with the proceeds from the sale of redeemable preferred units and member units as well as the sale of common stock and pre-funded warrants to purchase shares of its common stock in private placements and the sale of common stock in its initial public offering, follow-on public offering in March 2021 and under its at-the-market sales agreement. On January 11, 2024, the Company issued and sold in a private placement 16,973,103 shares of the Company’s common stock at a price per share of $ 5.53 and, to one investor in lieu of shares of common stock, pre-funded warrants to purchase 2,712,478 shares of common stock at a price of $ 5.529 per pre-funded warrant (the “January 2024 Private Placement”). The Company received $ 103.7 million of net proceeds from the January 2024 Private Placement after deducting offering costs. During the three months ended March 31, 2024 , the Company issued and sold 350,664 shares of its common stock pursuant to the Company's “at-the-market-offering” sales agreement (the “ATM Sales Agreement”), between the Company and Jefferies LLC (“Jefferies”). During the three months ended March 31, 2024 , the Company received net proceeds of $ 3.1 million, In accordance with Accounting Standards Codification 205-40, Going Concern, 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 the financial statements are issued. As of March 31, 2024 , the Company had an accumulated deficit of $ 683.1 million. During the three months ended March 31, 2024, the Company incurred a net loss of $ 24.3 million and used $ 25.2 million of cash in operations. The Company expects to continue to generate operating losses in the foreseeable future. Based upon its current operating plan, the Company expects that its cash, cash equivalents and available-for-sale securities of $ 206.1 , million excluding restricted cash of $ 1.8 million, as of March 31, 2024, will be sufficient to fund its operating expenses and capital expenditure requirements for at least twelve months from the date of issuance of these financial statements. However, the Company has based this estimate on assumptions that may prove to be wrong, and its operating plan may change as a result of many factors currently unknown to it. As a result, the Company could deplete its capital resources sooner than it currently expects. The Company expects to finance its future cash needs through a combination of equity offerings, debt financings, collaborations, strategic partnerships and alliances or licensing arrangements. If the Company is unable to obtain funding, the Company would be forced to delay, reduce or eliminate some or all of its research and development programs, preclinical and clinical testing or commercialization efforts, which could adversely affect its business prospects. Basis of Presentation The accompanying condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). The accompanying condensed consolidated financial statements include the accounts of the Company and its wholly owned or controlled subsidiaries. All intercompany accounts and transactions have been eliminated. In the opinion of management, the accompanying unaudited condensed consolidated financial statements include all adjustments, consisting of normal recurring accruals, necessary for a fair statement of the Company’s financial statements for interim periods in accordance with GAAP. The information included in this quarterly report on Form 10-Q should be read in conjunction with the Company’s consolidated financial statements and the accompanying notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023. The year-end condensed consolidated balance sheet data presented for comparative purposes was derived from the Company’s audited financial statements but does not include all disclosures required by GAAP. The results of operations for the three months ended March 31, 2024 are not necessarily indicative of the operating results for the full year or for any other subsequent interim period. Significant Judgments and Estimate The preparation of the Company’s condensed consolidated financial statements in conformity with GAAP requires management to make estimates, judgments 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 revenues and expenses during the reporting periods. Significant estimates and assumptions reflected in these condensed consolidated financial statements include, but are not limited to, estimates related to revenue recognition, the recognition of research and development expenses and equity-based compensation. 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 from the Company’s estimates. Summary of Significant Accounting Policies The Company’s accounting policies are described in the “Notes to Consolidated Financial Statements” in its Annual Report on Form 10-K for the year ended December 31, 2023 and updated, as necessary, in this report. Recently Issued Accounting Pronouncements In December 2023, the Financial Accounting Standards Board issued Accounting Standards Update ("ASU") No. 2023-09, “Income Taxes (Topic 740): Improvements to Income Tax Disclosures.” This ASU updates income tax disclosure requirements primarily by requiring specific categories and greater disaggregation within the rate reconciliation and disaggregation of income taxes paid by jurisdiction. This ASU is effective for annual periods beginning after December 15, 2024 and is applicable to the Company’s fiscal year beginning January 1, 2025, with early application permitted. The Company is currently evaluating the impact of adopting this ASU on its consolidated financial statements and disclosures.

License and Research Agreements

License and Research Agreements	3 Months Ended
	Mar. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
License and Research Agreements	2. License and Research Agreements On June 29, 2023, the Company entered into a license agreement (the “Agreement”) with ICS Maugeri S.p.A. SB (“Maugeri”) to focus on the development and commercialization of cardiac-related products by the Company based on Maugeri's inventions. Pursuant to the Agreement, Maugeri granted the Company an exclusive worldwide sublicensable license in certain Maugeri patent rights, including existing patent rights, and those in any improvements or know-how made in performance of the Agreement, and a non-exclusive worldwide sublicensable license in certain Maugeri know-how, including existing know-how, and on any improvement thereto, in each case, subject to certain conditions, that is necessary or reasonably useful to develop the licensed products under the terms of the Agreement. The Company will conduct certain activities agreed to by the parties with respect to the research and development of licensed products. A condition precedent to the effectiveness of the Agreement was regulatory review in Italy, which was completed in the third quarter of 2023 and, upon the completion of the condition precedent, the Agreement became effective. The Company paid to Maugeri an upfront license fee of € 1.5 million which was recorded as research and development expense during the second quarter of 2023. Additionally, the Company agreed to cumulative developmental, regulatory, and commercial milestone payments of up to € 15.0 million, cumulative sales milestone payments of up to € 15.0 million, upon achievement of specified milestone events, and tiered royalties on worldwide net sales in the low-to-mid-single-digits. The Agreement continues until the latest expiry of (i) the last valid claim (as defined in the Agreement), (ii) regulatory exclusivity, and (iii) all payment obligations. Either party may terminate the agreement for the other party’s uncured material breach. The Company may also terminate the agreement in its sole discretion upon 60 days ’ prior written notice to Maugeri and payment of a fee.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2024
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. Fair Value Measurements Certain assets and liabilities are carried at fair value under GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities or other inputs that are observable or can be corroborated by observable market data. • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. The following tables present information about the Company’s financial assets that are measured at fair value on a recurring basis: March 31, 2024 Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ — $ 61,371 $ — $ 61,371 Treasury bills — 28,348 — 28,348 Certificates of deposit — 260 — 260 Available-for-sale securities: Treasury bills — 52,632 — 52,632 Government bonds — 35,860 — 35,860 $ — $ 178,471 $ — $ 178,471 December 31, 2023 Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ — $ 62,141 $ — $ 62,141 Certificates of deposit — 257 — 257 Available-for-sale securities: Treasury bills — 49,625 — 49,625 $ — $ 112,023 $ — $ 112,023 As of March 31, 2024 and December 31, 2023, the fair values of the Company’s cash equivalents and available-for-sale securities were determined using Level 2 inputs. During the three months ended March 31, 2024 and the year ended December 31, 2023 , there were no transfers between Level 1, Level 2 and Level 3. At March 31, 2024 and December 31, 2023, the Company’s accounts payable, accrued expenses, and other current liabilities approximated their estimated fair values due to the short term nature of these financial instruments.

Available-for-Sale Securities

Available-for-Sale Securities	3 Months Ended
	Mar. 31, 2024
Investments, Debt and Equity Securities [Abstract]
Available-for-Sale Securities	4. Available-for-Sale Securities A summary of the Company's available-for-sale securities is presented below: March 31, 2024 Amortized Gross Gross Fair Investments: Treasury bills $ 52,634 $ 1 $ ( 3 ) $ 52,632 Government bonds 35,862 — ( 2 ) $ 35,860 $ 88,496 $ 1 $ ( 5 ) $ 88,492 December 31, 2023 Amortized Gross Gross Fair Investments: Treasury bills $ 49,610 $ 15 $ — $ 49,625 $ 49,610 $ 15 $ — $ 49,625 The estimated fair value and amortized cost of the Company’s available-for-sale securities as of by contractual maturity are summarized as follows: March 31, 2024 Amortized Fair Due in one year or less $ 88,496 $ 88,492 Total available-for-sale securities $ 88,496 $ 88,492 December 31, 2023 Amortized Fair Due in one year or less $ 49,610 $ 49,625 Total available-for-sale securities $ 49,610 $ 49,625 The weighted average contractual maturity of the Company’s available-for-sale securities was approximately 0.5 years and 0.4 years as of March 31, 2024 and December 31, 2023, respectively.

Property and Equipment, Net

Property and Equipment, Net	3 Months Ended
	Mar. 31, 2024
Property, Plant and Equipment [Abstract]
Property and Equipment, Net	5. Property and Equipment, Net Property and equipment, net, consists of the following: March 31, 2024 December 31, 2023 Laboratory equipment $ 16,051 $ 16,137 Furniture and fixtures 936 936 Computer equipment 842 842 Computer software 553 553 Leasehold improvements 481 481 Construction in process 580 410 Property and equipment, at cost 19,443 19,359 Less accumulated depreciation and amortization ( 13,052 ) ( 12,735 ) Property and equipment, net $ 6,391 $ 6,624 Depreciation and amortization expense was $ 0.3 million and $ 0.7 million for the three months ended March 31, 2024 and 2023, respectively. During the three months ended March 31, 2023 the Company recognized an impairment loss of $ 0.4 million. No impairment losses were recognized during the three months ended March 31, 2024.

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	3 Months Ended
	Mar. 31, 2024
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid Expenses and Other Current Assets	6. Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consist of the following: March 31, 2024 December 31, 2023 Prepaid research and development expenses $ 5,033 $ 3,980 Prepaid expenses and other assets 3,093 2,114 Total $ 8,126 $ 6,094

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	3 Months Ended
	Mar. 31, 2024
Payables and Accruals [Abstract]
Accrued Expenses and Other Current Liabilities	7. Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consist of the following: March 31, 2024 December 31, 2023 Accrued research and development $ 5,099 $ 2,614 Accrued compensation 3,194 5,948 Accrued other 2,034 1,575 Total $ 10,327 $ 10,137

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2024
Equity [Abstract]
Stockholders' Equity	8. Stockholders’ Equity On January 11, 2024, the Company issued and sold 16,973,103 shares of the Company’s common stock at a price per share of $ 5.53 and, to one investor in lieu of shares of common stock, pre-funded warrants to purchase 2,712,478 shares of common stock at a price of $ 5.529 per pre-funded warrant, in the January 2024 Private Placement. The Company received approximately $ 103.7 million of net proceeds from the January 2024 Private Placement after deducting offering costs. No warrants were exercised during the three months ended March 31, 2024. three months ended March 31, 2024 , the Company sold 350,664 shares of its common stock pursuant to the Company's "at-the-market offering" sales agreement, between the Company and Jefferies. During the three months ended March 31, 2024 , the Company received net proceeds of $ 3.1 million.

Equity-Based Compensation

Equity-Based Compensation	3 Months Ended
	Mar. 31, 2024
Share-Based Payment Arrangement [Abstract]
Equity-Based Compensation	9. Equity-Based Compensation In connection with the closing of the Company’s initial public offering, the Board of Directors and stockholders approved the 2018 Omnibus Incentive Plan (the “2018 Plan”), which provides for the reservation of 333,400 shares of common stock for equity awards. On June 16, 2020, the Company’s stockholders approved the 2020 Equity Incentive Plan (as amended or restated, the “2020 Plan”) which consisted of, at the time of approval (i) 200,000 shares of common stock and (ii) additional shares of common stock (up to 325,268 ) as is equal to (i) the number of shares reserved under the 2018 Plan that remain available for grant under the 2018 Plan as of immediately prior to the date the 2020 Plan was approved by the Company’s stockholders and (ii) the number of shares subject to awards granted under the 2018 Plan which awards expire, terminate or are otherwise surrendered, cancelled, forfeited or repurchased by the Company at their original issuance price pursuant to a contractual repurchase right. As of the effective date of the 2020 Plan, no further awards will be made under the 2018 Plan. Any options or awards outstanding under the 2018 Plan remain outstanding and effective and are governed by their existing terms. In June 2021, the Company’s stockholders approved an amendment to the 2020 Plan to reserve an additional 466,666 shares of common stock for issuance under the plan. On December 1, 2022, the Company's stockholders approved an amendment and restatement of the 2020 Plan to (i) increase the number of shares of common stock reserved for issuance under the plan by 866,666 shares to 1,533,333 shares, subject to adjustment in the event of stock splits and other similar events, (ii) provide for an annual increase, to be added on the first day of each fiscal year during the term of the plan, beginning with the fiscal year ending December 31, 2023, of 5 % of the number of shares of common stock outstanding on the first day of such fiscal year or a lesser number of shares determined by the Board of Directors, (iii) provide that up to 1,858,601 shares of common stock may be granted as “incentive stock options” under the 2020 Plan, (iv) extend the term of the plan to December 1, 2032 and (v) revise certain provisions of the plan relating to the Board of Director’s ability to delegate authority to make awards under the plan. Under the 2020 Plan, stock options may not be granted at less than fair value on the date of grant. As of March 31, 2024 , 322,909 shares remained available for future issuance under the 2020 Plan. In June 2021, the Company's stockholders also approved the 2021 Employee Stock Purchase Plan (“ESPP”), which provides for 73,525 shares to be available for purchase by eligible employees according to its terms. The first offering period under the ESPP commenced on September 1, 2021. On June 6, 2023, the Company's stockholders approved an amendment and restatement of the ESPP to (i) increase the number of shares of common stock reserved for issuance under the ESPP from 73,525 to 473,525 and (ii) provide for an annual increase to be added on the first day of each fiscal year, beginning with the fiscal year ending December 31, 2024 and ending with the fiscal year ending December 31, 2033, equal to the least of (a) 293,597 shares of common stock, (b) one percent ( 1 %) of the outstanding shares of common stock on such date and (c) the number of shares of common stock determined by the Board of Directors. The Company amended and restated the ESPP on November 12, 2023 to provide for 24-month offering periods. As of March 31, 2024 , 601,402 shares remained available for future issuance under the ESPP. In March 2024, the Board of Directors approved the 2024 Inducement Stock Incentive Plan (the "Inducement Plan"), which provides for the reservation of 1,000,000 shares of common stock for equity granted as an inducement material to the individual’s entering into employment with the Company and in accordance with the requirements of Nasdaq Stock Market Rule 5635(c)(4). As of March 31, 2024, 1,000,000 shares remained available for future issuance under the Inducement Plan. During the three months ended March 31, 2024 , the Company granted options to purchase 844,322 shares of common stock under the 2020 Plan and no options to purchase shares of common stock as an inducement award in accordance with Nasdaq Listing Rule 5635(c)(4). During the three months ended March 31, 2023 , the Company granted options to purchase 695,596 shares of common stock under the 2020 Plan and options to purchase 90,000 shares of common stock as an inducement award in accordance with Nasdaq Listing Rule 5635(c)(4). During the three months ended March 31, 2024 , the Company granted 896,887 restricted stock units under the 2020 Plan and no restricted stock units as an inducement award in accordance with Nasdaq Listing Rule 5635(c)(4). During the three months ended March 31, 2023 , the Company granted 347,997 restricted stock units under the 2020 Plan and 45,000 restricted stock units as an inducement award in accordance with Nasdaq Listing Rule 5635(c)(4). The Company recorded equity-based compensation expense related to all of its share-based awards to employees and non-employees in the following captions within its condensed consolidated statements of operations: Three Months Ended 2024 2023 Research and development $ 548 $ 898 General and administrative 1,063 1,220 Total $ 1,611 $ 2,118

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2024
Income Tax Disclosure [Abstract]
Income Taxes	10. Income Taxes During the three months ended March 31, 2024 and 2023 , the Company recorded no income tax benefits for the net operating losses incurred or for the research and development tax credits and orphan drug credits generated in each year due to its uncertainty of realizing a benefit from those items. The Company has provided a valuation allowance for the full amount of its net deferred tax assets because, at March 31, 2024 and December 31, 2023, it was more likely than not that any future benefit from deductible temporary differences and net operating loss and tax credit carryforwards would not be realized. As of March 31, 2024 and December 31, 2023 , the Company had no t recorded any amounts for unrecognized tax benefits. The Company files income tax returns as prescribed by the tax laws of the jurisdictions in which it operates. In the normal course of business, the Company is subject to examination by federal and state jurisdictions, where applicable. There are currently no pending income tax examinations. The Company’s C-Corporation tax years beginning with the year ended December 31, 2019 are open under statute. Any tax credit or net operating loss carryforward can be adjusted in future periods after the respective year of generation’s statute of limitation has closed.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	11. Commitments and Contingencies Letter of Credit The Company had an outstanding letter of credit in the amount of $ 1.8 million at March 31, 2024 and December 31, 2023, which was required as a condition of the Company’s office and laboratory lease. Indemnification Agreements In the ordinary course of business, the Company may provide indemnification of varying scope and terms to vendors, lessors, business partners and other parties with respect to certain matters, including, but not limited to, losses arising out of breach of such agreements or from intellectual property infringement claims made by third parties. In addition, the Company has entered into indemnification agreements with its executive officers and members of its Board of Directors that require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as executive officers or directors. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is, in many cases, unlimited. To date, the Company has not incurred any material costs as a result of such indemnification arrangements. The Company does not believe that the outcome of any claims under indemnification arrangements will have a material effect on its financial position, results of operations or cash flows, and it has not accrued any liabilities related to such obligations in its consolidated financial statements as of March 31, 2024 and December 31, 2023. Legal Proceedings The Company may periodically become subject to legal proceedings and claims arising in connection with ongoing business activities, including claims or disputes related to patents that have been issued or that are pending in the field of research on which the Company is focused. The Company is not aware of any material legal proceedings or claims as of March 31, 2024 .

Net Loss per Share

Net Loss per Share	3 Months Ended
	Mar. 31, 2024
Earnings Per Share [Abstract]
Net Loss per Share	12. Net Loss per Share Basic and diluted net loss per share were calculated as follows: The numerator for basic and diluted net loss per share is as follows: Three Months Ended 2024 2023 Net loss $ ( 24,303 ) $ ( 30,070 ) The denominator is as follows: Three Months Ended 2024 2023 Weighted average shares of common stock outstanding, 35,740,970 19,567,635 Weighted average shares of pre-funded warrants to 2,414,403 — Total 38,155,373 19,567,635 Included within weighted average shares of common stock outstanding for the three months ended March 31, 2024 and 2023 are 2,712,478 and 0 , respectively, shares of common stock issuable upon the exercise of the pre-funded warrants as the warrants are exercisable at any time for nominal consideration, and as such, the shares are considered outstanding for the purpose of calculating basic and diluted net loss per share. Net loss per share, basic and diluted is as follows: Three Months Ended 2024 2023 Net loss per share, basic and diluted $ ( 0.64 ) $ ( 1.54 ) The following potential common stock equivalents, presented based on amounts outstanding at each period end, were excluded from the calculation of diluted net loss per share for the periods indicated because including them would have had an anti-dilutive effect: Three Months Ended 2024 2023 Options to purchase common stock 2,864,672 2,113,510 Nonvested restricted stock units 1,576,230 841,570 Total 4,440,902 2,955,080

Restructuring

Restructuring	3 Months Ended
	Mar. 31, 2024
Restructuring and Related Activities [Abstract]
Restructuring	13. Restructuring In November 2022, the Company’s Board of Directors approved a plan to reduce the Company’s workforce by approximately 18 percent. These reductions were completed by December 5, 2022. This plan was designed to streamline the Company’s operating structure following the Acquisition. The Company recorded a restructuring charge in the fourth quarter of 2022 of $ 5.7 million related to the reduction in force, consisting of severance and other employee termination benefits. The Company paid $ 0.1 million of this amount during the three months ended March 31, 2024 and $ 3.7 million during the year ended December 31, 2023 . The Company expects that the remaining $ 0.1 million will be paid during the second quarter of 2024. The following table provides a rollforward of activity associated with accrued restructuring charges for the periods indicated: One-Time Employee Accrued restructuring charges as of December 31, 2022 $ 3,921 Accrual recorded as a result of restructuring charges — Amounts paid during the period ( 3,669 ) Accrued restructuring charges as of December 31, 2023 $ 252 Accrual recorded as a result of restructuring charges — Amounts paid during the period ( 143 ) Accrued restructuring charges as of March 31, 2024 $ 109

Nature of the Business and Ba_2

Nature of the Business and Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2024
Accounting Policies [Abstract]
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In December 2023, the Financial Accounting Standards Board issued Accounting Standards Update ("ASU") No. 2023-09, “Income Taxes (Topic 740): Improvements to Income Tax Disclosures.” This ASU updates income tax disclosure requirements primarily by requiring specific categories and greater disaggregation within the rate reconciliation and disaggregation of income taxes paid by jurisdiction. This ASU is effective for annual periods beginning after December 15, 2024 and is applicable to the Company’s fiscal year beginning January 1, 2025, with early application permitted. The Company is currently evaluating the impact of adopting this ASU on its consolidated financial statements and disclosures.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2024
Fair Value Disclosures [Abstract]
Summary of Financial Assets that are Measured at Fair Value on a Recurring Basis	The following tables present information about the Company’s financial assets that are measured at fair value on a recurring basis: March 31, 2024 Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ — $ 61,371 $ — $ 61,371 Treasury bills — 28,348 — 28,348 Certificates of deposit — 260 — 260 Available-for-sale securities: Treasury bills — 52,632 — 52,632 Government bonds — 35,860 — 35,860 $ — $ 178,471 $ — $ 178,471 December 31, 2023 Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ — $ 62,141 $ — $ 62,141 Certificates of deposit — 257 — 257 Available-for-sale securities: Treasury bills — 49,625 — 49,625 $ — $ 112,023 $ — $ 112,023

Available-for-Sale Securities (

Available-for-Sale Securities (Tables)	3 Months Ended
	Mar. 31, 2024
Investments, Debt and Equity Securities [Abstract]
Schedule of Available-for-Sale Securities	A summary of the Company's available-for-sale securities is presented below: March 31, 2024 Amortized Gross Gross Fair Investments: Treasury bills $ 52,634 $ 1 $ ( 3 ) $ 52,632 Government bonds 35,862 — ( 2 ) $ 35,860 $ 88,496 $ 1 $ ( 5 ) $ 88,492 December 31, 2023 Amortized Gross Gross Fair Investments: Treasury bills $ 49,610 $ 15 $ — $ 49,625 $ 49,610 $ 15 $ — $ 49,625
Summary Estimated Fair Value and Amortized Cost of Available-for-Sale Securities by Contractual Maturity	The estimated fair value and amortized cost of the Company’s available-for-sale securities as of by contractual maturity are summarized as follows: March 31, 2024 Amortized Fair Due in one year or less $ 88,496 $ 88,492 Total available-for-sale securities $ 88,496 $ 88,492 December 31, 2023 Amortized Fair Due in one year or less $ 49,610 $ 49,625 Total available-for-sale securities $ 49,610 $ 49,625

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	3 Months Ended
	Mar. 31, 2024
Property, Plant and Equipment [Abstract]
Summary of Property and Equipment, Net	Property and equipment, net, consists of the following: March 31, 2024 December 31, 2023 Laboratory equipment $ 16,051 $ 16,137 Furniture and fixtures 936 936 Computer equipment 842 842 Computer software 553 553 Leasehold improvements 481 481 Construction in process 580 410 Property and equipment, at cost 19,443 19,359 Less accumulated depreciation and amortization ( 13,052 ) ( 12,735 ) Property and equipment, net $ 6,391 $ 6,624

Prepaid Expenses and Other Cu_2

Prepaid Expenses and Other Current Assets (Tables)	3 Months Ended
	Mar. 31, 2024
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consist of the following: March 31, 2024 December 31, 2023 Prepaid research and development expenses $ 5,033 $ 3,980 Prepaid expenses and other assets 3,093 2,114 Total $ 8,126 $ 6,094

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	3 Months Ended
	Mar. 31, 2024
Payables and Accruals [Abstract]
Summary of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consist of the following: March 31, 2024 December 31, 2023 Accrued research and development $ 5,099 $ 2,614 Accrued compensation 3,194 5,948 Accrued other 2,034 1,575 Total $ 10,327 $ 10,137

Equity-Based Compensation (Tabl

Equity-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2024
Share-Based Payment Arrangement [Abstract]
Schedule of Equity-based Compensation Expense	The Company recorded equity-based compensation expense related to all of its share-based awards to employees and non-employees in the following captions within its condensed consolidated statements of operations: Three Months Ended 2024 2023 Research and development $ 548 $ 898 General and administrative 1,063 1,220 Total $ 1,611 $ 2,118

Net Loss per Share (Tables)

Net Loss per Share (Tables)	3 Months Ended
	Mar. 31, 2024
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Net Loss per Share	The numerator for basic and diluted net loss per share is as follows: Three Months Ended 2024 2023 Net loss $ ( 24,303 ) $ ( 30,070 ) The denominator is as follows: Three Months Ended 2024 2023 Weighted average shares of common stock outstanding, 35,740,970 19,567,635 Weighted average shares of pre-funded warrants to 2,414,403 — Total 38,155,373 19,567,635 Included within weighted average shares of common stock outstanding for the three months ended March 31, 2024 and 2023 are 2,712,478 and 0 , respectively, shares of common stock issuable upon the exercise of the pre-funded warrants as the warrants are exercisable at any time for nominal consideration, and as such, the shares are considered outstanding for the purpose of calculating basic and diluted net loss per share. Net loss per share, basic and diluted is as follows: Three Months Ended 2024 2023 Net loss per share, basic and diluted $ ( 0.64 ) $ ( 1.54 )
Schedule of Antidilutive Securities Excluded from Calculation of Diluted Net Loss per Share	The following potential common stock equivalents, presented based on amounts outstanding at each period end, were excluded from the calculation of diluted net loss per share for the periods indicated because including them would have had an anti-dilutive effect: Three Months Ended 2024 2023 Options to purchase common stock 2,864,672 2,113,510 Nonvested restricted stock units 1,576,230 841,570 Total 4,440,902 2,955,080

Restructuring (Tables)

Restructuring (Tables)	3 Months Ended
	Mar. 31, 2024
Restructuring and Related Activities [Abstract]
Schedule of Accrued Restructuring Charges	The following table provides a rollforward of activity associated with accrued restructuring charges for the periods indicated: One-Time Employee Accrued restructuring charges as of December 31, 2022 $ 3,921 Accrual recorded as a result of restructuring charges — Amounts paid during the period ( 3,669 ) Accrued restructuring charges as of December 31, 2023 $ 252 Accrual recorded as a result of restructuring charges — Amounts paid during the period ( 143 ) Accrued restructuring charges as of March 31, 2024 $ 109

Nature of the Business and Ba_3

Nature of the Business and Basis of Presentation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
	Jan. 11, 2024	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Net loss		$ 24,303	$ 30,070
Accumulated deficit		683,056		$ 658,753
Net cash used in operating activities		25,192	$ 27,995
Cash, cash equivalents and available-for-sale securities		$ 206,100
Common stock, shares authorized		60,000,000		60,000,000
Restricted cash		$ 1,800
At-the-Market Offering Sales Agreement [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Common stock shares issued		350,664
Proceeds from issuance of common stock		$ 3,100
Private Placement [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Net proceeds from private placement	$ 103,700
Common Stock [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Common stock shares issued		350,664
Common Stock [Member] | At-the-Market Offering Sales Agreement [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Common stock shares issued		350,664
Common Stock [Member] | Private Placement [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Common stock shares issued	16,973,103	16,973,103
Common stock issued price per share	$ 5.53
Pre Funded Warrants [Member] | Private Placement [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Warrants outstanding	2,712,478
Common stock warrants exercise price per share	$ 5.529

License and Research Agreemen_2

License and Research Agreements - Additional Information (Detail) - Maugeri License Agreement [Member]	Jun. 29, 2023 EUR (€)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Agreement termination notice period	60 days
Upfront license fee	€ 1,500,000
Maximum [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Cumulative developmental, regulatory, and commercial milestone payments	15,000,000
Cumulative sales milestone payments	€ 15,000,000

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Financial Assets that are Measured at Fair Value on a Recurring Basis (Detail) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Assets:
Available-for-sale securities	$ 88,492	$ 49,625
Assets Fair Value Disclosure	178,471	112,023
Treasury Bills [Member]
Assets:
Cash equivalents	28,348
Available-for-sale securities	52,632	49,625
Government Bonds [Member]
Assets:
Available-for-sale securities	35,860
Money Market Funds [Member]
Assets:
Cash equivalents	61,371	62,141
Certificates of Deposit [Member]
Assets:
Cash equivalents	260	257
Level 2 [Member]
Assets:
Assets Fair Value Disclosure	178,471	112,023
Level 2 [Member] | Treasury Bills [Member]
Assets:
Cash equivalents	28,348
Available-for-sale securities	52,632	49,625
Level 2 [Member] | Government Bonds [Member]
Assets:
Available-for-sale securities	35,860
Level 2 [Member] | Money Market Funds [Member]
Assets:
Cash equivalents	61,371	62,141
Level 2 [Member] | Certificates of Deposit [Member]
Assets:
Cash equivalents	$ 260	$ 257

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Fair value, assets, transfers into level 3, amount	$ 0	$ 0
Fair value, assets, transfers out of level 3, amount	0	0
Fair value, assets, transfers into level 2, amount	0	0
Fair value, assets, transfers out of level 2, amount	0	0
Fair value, assets, transfers into level 1, amount	0	0
Fair value, assets, transfers out of level 1, amount	$ 0	$ 0

Available-for-Sale Securities -

Available-for-Sale Securities - Schedule of Available-for-Sale Securities (Detail) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 88,496	$ 49,610
Gross Unrealized Gain	1	15
Gross Unrealized Loss	(5)
Fair Value	88,492	49,625
Treasury Bills [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	52,634	49,610
Gross Unrealized Gain	1	15
Gross Unrealized Loss	(3)
Fair Value	52,632	$ 49,625
Government Bonds [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	35,862
Gross Unrealized Loss	(2)
Fair Value	$ 35,860

Available-for-Sale Securities_2

Available-for-Sale Securities - Summary Estimated Fair Value and Amortized Cost of Available-for-Sale Securities by Contractual Maturity (Detail) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Due in one year or less, amortized cost	$ 88,496	$ 49,610
Amortized Cost	88,496	49,610
Due in one year or less, fair value	88,492	49,625
Total available-for-sale securities, fair value	$ 88,492	$ 49,625

Available-for-Sale Securities_3

Available-for-Sale Securities - Additional Information (Detail)	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Available-for-sale securities average maturity period	6 months	4 months 24 days

Property and Equipment, Net - S

Property and Equipment, Net - Summary of Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	$ 19,443	$ 19,359
Less accumulated depreciation and amortization	(13,052)	(12,735)
Property and equipment, net	6,391	6,624
Laboratory Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	16,051	16,137
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	936	936
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	842	842
Computer Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	553	553
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	481	481
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	$ 580	$ 410

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Property, Plant and Equipment [Abstract]
Impairment loss	$ 0	$ 0.4
Depreciation and amortization expense	$ 0.3	$ 0.7

Prepaid Expenses and Other Cu_3

Prepaid Expenses and Other Current Assets - Schedule of Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid research and development expenses	$ 5,033	$ 3,980
Prepaid expenses and other assets	3,093	2,114
Prepaid expenses and other current assets	$ 8,126	$ 6,094

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities - Summary of Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Accrued Expenses And Other Current Liabilities [Line Items]
Accrued expenses and other current liabilities	$ 10,327	$ 10,137
Accrued Research and Development [Member]
Accrued Expenses And Other Current Liabilities [Line Items]
Accrued expenses and other current liabilities	5,099	2,614
Accrued Compensation [Member]
Accrued Expenses And Other Current Liabilities [Line Items]
Accrued expenses and other current liabilities	3,194	5,948
Accrued Other [Member]
Accrued Expenses And Other Current Liabilities [Line Items]
Accrued expenses and other current liabilities	$ 2,034	$ 1,575

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended
	Jan. 11, 2024	Mar. 31, 2024
Class Of Stock [Line Items]
Warrants exercised		0
Private Placement [Member]
Class Of Stock [Line Items]
Company received net proceeds	$ 103.7
At-the-Market Offering Sales Agreement [Member]
Class Of Stock [Line Items]
Stock issued and sold		350,664
Proceeds from issuance of common stock, net of issuance costs		$ 3.1
Common Stock [Member]
Class Of Stock [Line Items]
Stock issued and sold		350,664
Common Stock [Member] | Private Placement [Member]
Class Of Stock [Line Items]
Stock issued and sold	16,973,103	16,973,103
Common stock issued price per share	$ 5.53
Common Stock [Member] | At-the-Market Offering Sales Agreement [Member]
Class Of Stock [Line Items]
Stock issued and sold		350,664
Pre-Funded Warrants [Member] | Private Placement [Member]
Class Of Stock [Line Items]
Common stock warrants exercise price per share	$ 5.529
Warrants outstanding	2,712,478

Equity-Based Compensation - Add

Equity-Based Compensation - Additional Information (Detail) - shares				1 Months Ended	3 Months Ended
	Nov. 12, 2023	Jun. 05, 2023	Jun. 16, 2020	Jun. 30, 2021	Mar. 31, 2024	Mar. 31, 2023	Jun. 06, 2023	Dec. 01, 2022
Inducement Award [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock purchased					90,000
Restricted stock units granted					0	45,000
Incentive Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for future issuance								1,858,601
2018 Omnibus Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized for common stock for equity awards					333,400
2020 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized for common stock for equity awards			200,000
Number of additional shares authorized for common stock for equity awards				466,666
Number of shares available for future issuance					322,909
Common stock purchased					844,322	695,596
2020 Equity Incentive Plan [Member] | Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units granted					896,887	347,997
2020 Equity Incentive Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of additional shares authorized for common stock for equity awards			325,268
2021 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized for common stock for equity awards				73,525
Number of shares available for future issuance					601,402
Amended and Restated 2020 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of additional shares authorized for common stock for equity awards					866,666
Number of share reserved for future issuance								1,533,333
Percentage of number of shares outstanding					5%
Amendment and Restatement of ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of additional shares authorized for common stock for equity awards		73,525
Number of share reserved for future issuance							473,525
Percentage of number of shares outstanding					1%
Offering period	24 months
Amendment and Restatement of ESPP [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of additional shares authorized for common stock for equity awards					293,597
2024 Inducement Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized for common stock for equity awards					1,000,000
Number of shares available for future issuance					1,000,000

Equity-Based Compensation - Sch

Equity-Based Compensation - Schedule of Equity-based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 1,611	$ 2,118
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	548	898
General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 1,063	$ 1,220

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Income tax expense (benefit)	$ 0	$ 0
Unrecognized tax benefits	$ 0		$ 0

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Office and Laboratory Lease [Member]
Commitment And Contingencies [Line Items]
Letter of credit outstanding amount	$ 1.8	$ 1.8

Net Loss per Share - Schedule o

Net Loss per Share - Schedule of Basic and Diluted Net Loss per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Earnings Per Share Basic [Line Items]
Net loss	$ (24,303)	$ (30,070)
Weighted average shares of common stock outstanding, basic	38,155,373	19,567,635
Weighted average shares of common stock outstanding, diluted	38,155,373	19,567,635
Net loss per share, basic	$ (0.64)	$ (1.54)
Net loss per share, diluted	$ (0.64)	$ (1.54)
Common Stock [Member]
Earnings Per Share Basic [Line Items]
Weighted average shares of common stock outstanding, basic	35,740,970	19,567,635
Weighted average shares of common stock outstanding, diluted	35,740,970	19,567,635
Pre-Funded Warrants [Member]
Earnings Per Share Basic [Line Items]
Weighted average shares of common stock outstanding, basic	2,414,403
Weighted average shares of common stock outstanding, diluted	2,414,403

Net Loss per Share - Additional

Net Loss per Share - Additional Information (Detail) - shares	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Common stock issuable upon exercise of pre-funded warrants	2,712,478	0

Net Loss per Share - Schedule_2

Net Loss per Share - Schedule of Antidilutive Securities Excluded from Calculation of Diluted Net Loss per Share (Detail) - shares	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common stock equivalents excluded from calculation of diluted net loss per share	4,440,902	2,955,080
Options to Purchase Common Stock [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common stock equivalents excluded from calculation of diluted net loss per share	2,864,672	2,113,510
Nonvested Restricted Stock Units [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common stock equivalents excluded from calculation of diluted net loss per share	1,576,230	841,570

Restructuring - Addition Inform

Restructuring - Addition Information (Detail) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		12 Months Ended
	Nov. 30, 2022	Mar. 31, 2024	Dec. 31, 2022	Dec. 31, 2023	Jun. 30, 2024
Restructuring Cost and Reserve [Line Items]
Number of headcount reduced, percentage	18%
Restructuring charges related to severance payment and other employee-related costs			$ 5,700
Restructuring charges were paid		$ 143		$ 3,669
Forcast [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges expected to be paid					$ 100

Restructuring - Schedule of Acc

Restructuring - Schedule of Accrued Restructuring Charges (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Restructuring Cost and Reserve [Line Items]
Accrued restructuring charges, beginning balance	$ 252	$ 3,921
Amounts paid during the period	(143)	(3,669)
Accrued restructuring charges, ending balance	$ 109	$ 252