0000950170-24-098582 | 10-Q/A | XBRL Viewer | Eledon Pharmaceuticals INC

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Going Concern and Management's Plans - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands			3 Months Ended
	May 06, 2024	May 05, 2023	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023	Apr. 28, 2023
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Net Income (Loss)			$ (23,631)	$ (10,772)
Accumulated deficit			(343,033)		$ (319,402)
Cash and cash equivalents and short-term investments			$ 42,900
Common stock, shares issued			24,813,130		24,213,130
Common stock, par value			$ 0.001		$ 0.001
Accredited Investor [Member] \| Private Placement [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Warrant exercise price						$ 3
Accredited Investor [Member] \| Private Placement [Member] \| Pre-funded Warrants [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Warrant exercise price						$ 0.001
Securities Purchase Agreement Initial Closing [Member] \| Private Placement [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Common warrants issued		$ 35,000
Securities Purchase Agreement Initial Closing [Member] \| Private Placement [Member] \| Pre-funded Warrants [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Common stock, shares issued		6,421,350
Securities Purchase Agreement Initial Closing [Member] \| Accredited Investor [Member] \| Private Placement [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Common warrants issued		$ 45,500
Common stock, shares issued		8,730,168				15,151,518
Common stock, par value						$ 0.001
Common stock warrants to purchase common stock shares		15,151,518				15,151,518
Securities Purchase Agreement Second and Third Closing [Member] \| Accredited Investor [Member] \| Private Placement [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Common warrants issued		$ 105,000
Securities Purchase Agreement [Member] \| Accredited Investor [Member] \| Private Placement [Member] \| Subsequent Event [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Common stock, shares issued	13,110,484
Common stock, par value	$ 0.001
Stock price per share	$ 2.37
Gross proceeds	$ 50,000
Net proceeds after deducting offering costs	$ 47,600
Securities Purchase Agreement [Member] \| Accredited Investor [Member] \| Private Placement [Member] \| Pre-funded Warrants [Member] \| Subsequent Event [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Common stock warrants to purchase common stock shares	7,989,516
Stock price per share	$ 2.369
Warrant exercise price	$ 0.001

Stock-based Compensation

3 Months Ended

Mar. 31, 2024

Share-Based Payment Arrangement [Abstract]

Stock-Based Compensation

Note 10. Stock-based Compensation

The Company recognizes compensation expense for all stock-based awards based on the grant-date estimated fair value.

The fair value of stock options is determined using the Black-Scholes option pricing model, using assumptions which are subjective and require significant judgment and estimation by management. The risk-free rate assumption was based on observed yields from governmental zero-coupon bonds with an equivalent term. The expected volatility assumption was based on historical volatilities of a group of comparable industry companies whose share prices are publicly available. The peer group was developed based on companies in the pharmaceutical industry. The expected term of stock options represents the weighted-average period that the stock options are expected to be outstanding. Because the Company does not have historical exercise behavior, the Company determined the expected life assumption using the simplified method for stock options granted to employees, which is an average of the options ordinary vesting period and the contractual term. For stock options granted to the Company’s board of directors (the “Board”), the Company determined the expected life assumption using the simplified method as the starting point with an average period of twelve (12) months added to take into account the extended range of time of 12 to 18 months that vested stock options granted to Board members may be exercised upon termination. The expected dividend assumption was based on the Company’s history and expectation of dividend payouts. The Company has not paid and does not expect to pay dividends at any time in the foreseeable future. The Company recognizes forfeitures on an actual basis and as such did not estimate forfeitures to calculate stock-based compensation.

Restricted Stock Units (“RSUs”) are measured and recognized based on the quoted market price of our common stock on the date of grant.

On June 21, 2023, the Company held its Annual Meeting of Stockholders (the “Annual Meeting”). At the Annual Meeting, the Company’s stockholders approved an amendment to the Company's 2020 Long Term Incentive Plan (the “2020 Plan”). The 2020 Plan, as amended, (i) reflects an increase in the limit on the aggregate number of shares of the Company’s

common stock that may be delivered pursuant to all awards granted under the 2020 Incentive Plan by an additional 9,600,000 shares so that the new aggregate share limit under the 2020 Plan is 14,460,000 shares, and (ii) extends the date through which the Company may grant new awards under the 2020 Plan from November 15, 2030 to April 26, 2033.

On May 1, 2023, the Company issued stock option awards to its employees with both time-based and performance-based vesting requirements, totaling 7,381,857 stock options, with 1,476,372 of the granted stock options subject to the Company’s customary time-based vesting schedule. The remaining 5,905,485 stock options granted are subject to both customary time-based vesting requirements and performance-based vesting requirements that are based on the same clinical development milestones applicable to the Second and Third Closings of the 2023 Private Placement as specified in the 2023 Securities Purchase Agreement.

In December 2023, the Company amended the performance-based vesting requirements with its named executive officers and other employees that upon the Second Closing and Third Closing, a full or prorated amount of each closing installment shall vest based on the percentage of funding received relative to the total funding opportunity represented by the investors’ Second Closing and Third Closing subscription amounts.

The 2014 Plan was closed to new grants following the initial approval of the 2020 Plan, and therefore, there were no shares reserved for issuance under the 2014 Plan as of March 31, 2024. The number of shares reserved for issuance under the 2020 Plan and ESPP was 2,813,742 and 24,077 shares, respectively, as of March 31, 2024.

Total stock-based compensation expense was recognized in our condensed consolidated statements of operations and comprehensive loss as follows (in thousands):


	For the Three Months Ended March 31,
	2024		2023
Research and development	$	349	$	397
General and administrative		1,345		984
Total stock-based compensation	$	1,694	$	1,381

Commitments and Contingencies - Schedule of Future Payments Under Noncancelable Operating Leases (Detail) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
2024 (remainder of)	$ 287
Total minimum lease payments	287
Less imputed interest	(3)
Present value of lease liabilities	284
Less current portion of operating lease liabilities	(284)	$ (383)
Non-current operating lease liabilities	$ 0

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	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

Description of Business - Additional Information (Detail)	Sep. 14, 2020
Anelixis [Member]
Description Of Business [Line Items]
Date of acquisition	Sep. 14, 2020

Stockholders' Equity (Deficit) - Schedule of Series X1 Convertible Preferred Stock Warrant Activity (Detail)	3 Months Ended
	Mar. 31, 2024 shares
Class Of Warrant Or Right [Line Items]
Ending Balance	20,964,302
Preferred Stock Warrants [Member]
Class Of Warrant Or Right [Line Items]
Beginning Balance	50,207.419
Issued	0
Exercised	0
Cancelled/Expired	0
Ending Balance	50,207.419

Fair Value Measurements (As Restated) (Tables)

3 Months Ended

Mar. 31, 2024

Table Text Block Supplement [Abstract]

Financial Instruments Measured At Fair Value On A Recurring Basis

The following table summarizes the Company's financial asset instruments measured at fair value on a recurring basis as of March 31, 2024 and December 31, 2023 (in thousands). Included within cash and cash equivalents on the condensed consolidated balance sheets, but excluded from the fair value hierarchy table, are cash deposits held at financial institutions.


	March 31, 2024
	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents:
Money market funds	$	4,098	$	—	$	—	$	4,098
Total cash equivalents	$	4,098	$	—	$	—	$	4,098

Short-term investments:
U.S. government securities	$	—	$	20,441	$	—	$	20,441
U.S. government agency securities		—		16,766		—		16,766
Total short-term investments	$	—	$	37,207	$	—	$	37,207

Total financial assets	$	4,098	$	37,207	$	—	$	41,305


	December 31, 2023
	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents:
Money market funds	$	4,246	$	—	$	—	$	4,246
Total cash equivalents	$	4,246	$	—	$	—	$	4,246

Short-term investments:
U.S. government securities	$	—	$	33,213	$	—	$	33,213
U.S. government agency securities		—		13,277		—		13,277
Total short-term investments	$	—	$	46,490	$	—	$	46,490

Total financial assets	$	4,246	$	46,490	$	—	$	50,736

Summary of Warrant Liabilities Measured at Fair Value on a Recurring Basis

The following table summarizes the Company's warrant liabilities (see Note 9) measured at fair value on a recurring basis as of March 31, 2024 and December 31, 2023 (in thousands) and was based on significant inputs not observable in the market, which represents a Level 3 measurement within the fair value hierarchy.


	March 31, 2024
	Level 1		Level 2		Level 3		Total
Warrant liabilities	$	—	$	—	$	89,547	$	89,547


	December 31, 2023
	Level 1		Level 2		Level 3		Total
Warrant liabilities	$	—	$	—	$	76,211	$	76,211

Schedule of Aggregate Fair Values of Warrant Liability

The following table provides a roll-forward of the aggregate fair value of the warrant liability categorized with Level 3 inputs:


	Warrants
Balance as of December 31, 2023	$	76,211
Change in fair value of warrant liabilities		13,336
Balance as of March 31, 2024	$	89,547

Prepaid Expenses and Other Current Assets (Tables)

3 Months Ended

Mar. 31, 2024

Prepaid Expense and Other Assets, Current [Abstract]

Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consisted of the following as of March 31, 2024 and December 31, 2023 (in thousands):


	March 31,		December 31,
	2024		2023
Prepaid insurance	$	441	$	624
Prepaid clinical		4,211		4,128
Prepaid other		409		185
Other current assets		54		90
Total prepaid expenses and other current assets	$	5,115	$	5,027

Fair Value Measurements (As Restated) - Summary of Warrant Liabilities Measured at Fair value on a Recurring Basis (Details) - Fair Value, Recurring [Member] - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities measured at fair value	$ 89,547	$ 76,211
Fair Value Inputs, Level 3 [Member] \| Warrant Liabilities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities measured at fair value	$ 89,547	$ 76,211

Commitments and Contingencies - Additional Information (Detail)			3 Months Ended		12 Months Ended
	Aug. 12, 2022	Nov. 04, 2021 ft²	Mar. 31, 2024 USD ($) Milestone	Mar. 31, 2023 USD ($) Milestone	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($) ft²	Dec. 31, 2021 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Other Commitments [Line Items]
Rental expense			$ 100,000	$ 100,000
Remaining term of office lease			9 months
Debt outstanding			$ 0
Indemnification obligations amount			0
Contingent liabilities			$ 0
ALS Therapy Development Foundation, Inc. License Agreement [Member]
Other Commitments [Line Items]
Fee due for milestones achieved								$ 1,000,000.0	$ 1,000,000.0
Common stock issued in lieu of making a cash payment								$ 1,000,000.0	$ 1,000,000.0
Number of Milestones Achieved \| Milestone			0	0
Remaining milestone payments for first licensed product			$ 6,000,000.0
Annual License Maintenance Fee					$ 100,000	$ 100,000	$ 100,000
ALS Therapy Development Foundation, Inc. License Agreement [Member] \| Achievement of 500 Million Aggregate Sales [Member]
Other Commitments [Line Items]
Reaching of aggregate net sales			500,000,000.0
Amount of one-time milestone payment			15,000,000.0
ALS Therapy Development Foundation, Inc. License Agreement [Member] \| Achievement of 1 Billion Aggregate Sales [Member]
Other Commitments [Line Items]
Reaching of aggregate net sales			1,000,000,000.0
Amount of one-time milestone payment			$ 30,000,000.0
Maximum [Member]
Other Commitments [Line Items]
Remaining term of office lease			1 year
Maximum [Member] \| ALS Therapy Development Foundation, Inc. License Agreement [Member]
Other Commitments [Line Items]
Development and regulatory milestone payments			$ 2,500,000
Irvine, California [Member]
Other Commitments [Line Items]
Area of office space \| ft²						5,197
Lease expiration date	Dec. 31, 2024
Burlington, Massachusetts [Member]
Other Commitments [Line Items]
Area of office space \| ft²		6,138
Lease expiration date		Nov. 20, 2024

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended
Pay vs Performance Disclosure - USD ($) $ in Thousands	Mar. 31, 2024	Mar. 31, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ (23,631)	$ (10,772)

Stockholders' Equity (Deficit) - Additional Information (Detail) - USD ($)					3 Months Ended
	May 16, 2023	May 05, 2023	Apr. 28, 2023	Mar. 31, 2021	Mar. 31, 2024	Jan. 30, 2024	Dec. 31, 2023	Nov. 06, 2023	Nov. 02, 2023	Jul. 14, 2023	Jul. 10, 2023
Class Of Stock [Line Items]
Warrants available for exercise					20,964,302
Debt outstanding					$ 0
Common stock, shares issued					24,813,130		24,213,130
Common stock par value					$ 0.001		$ 0.001
Net proceeds after deducting offering costs					$ 1,000
Preferred stock, shares authorized					5,000,000		5,000,000
Preferred stock, par value					$ 0.001		$ 0.001
Armistice Capital Master Fund Ltd [Member] \| Securities Purchase Agreement [Member]
Class Of Stock [Line Items]
Number of pre-funded warrants exercised for common stock						600,000			653,000		501,197
Common stock, shares issued						600,000		653,000		501,197
Warrant exercise price per share						$ 0.001			$ 0.001		$ 0.001
Series X1 Preferred Stock [Member]
Class Of Stock [Line Items]
Warrants available for exercise					50,207.419
Shares of common stock issued upon conversion of each share of preferred stock					2,789,301
Series X1 Non-voting Convertible Preferred Stock [Member]
Class Of Stock [Line Items]
Preferred stock, shares authorized					515,000		515,000
Preferred stock, par value					$ 0.001		$ 0.001
Preferred stock, shares outstanding					110,086		110,086
Preferred stock, shares issued					110,086		110,086
Series X Non-Voting Convertible Preferred Stock [Member]
Class Of Stock [Line Items]
Preferred stock, shares authorized					10,000
Preferred stock, shares outstanding					4,422		4,422
Preferred stock, shares issued					4,422		4,422
Common Stock [Member]
Class Of Stock [Line Items]
Warrants available for exercise					20,964,302
Common Stock [Member] \| Series X Non-Voting Convertible Preferred Stock [Member]
Class Of Stock [Line Items]
Shares of common stock issued upon conversion of each share of preferred stock					55.5556
Pre-funded Warrants [Member] \| Accredited Investor [Member]
Class Of Stock [Line Items]
Class of Warrant Subject to Specified Beneficial Ownership Limitations Percentage			9.99%
Common Stock Warrants [Member]
Class Of Stock [Line Items]
Warrants available for exercise							21,564,302
Common Stock Warrants [Member] \| Accredited Investor [Member]
Class Of Stock [Line Items]
Class of Warrant Subject to Specified Beneficial Ownership Limitations Percentage			9.99%
Private Placement Warrants [Member] \| Accredited Investor [Member]
Class Of Stock [Line Items]
Warrant exercise price per share			$ 3
Private Placement Warrants [Member] \| Securities Purchase Agreement Initial Closing [Member]
Class Of Stock [Line Items]
Common warrants issued		$ 35,000,000
Net proceeds after deducting offering costs		$ 33,000,000
Private Placement Warrants [Member] \| Securities Purchase Agreement Initial Closing [Member] \| Accredited Investor [Member]
Class Of Stock [Line Items]
Common stock, shares issued		8,730,168	15,151,518
Common stock par value			$ 0.001
Common stock warrants exercisable		15,151,518	15,151,518
Common warrants issued		$ 45,500,000
Private Placement Warrants [Member] \| Securities Purchase Agreement Second Closing [Member] \| Accredited Investor [Member]
Class Of Stock [Line Items]
Common stock, shares issued			20,202,024
Private Placement Warrants [Member] \| Securities Purchase Agreement Third Closing [Member] \| Accredited Investor [Member]
Class Of Stock [Line Items]
Common stock, shares issued			25,252,530
Private Placement Warrants [Member] \| Securities Purchase Agreement Second and Third Closing [Member] \| Accredited Investor [Member]
Class Of Stock [Line Items]
Common warrants issued		$ 105,000,000
Private Placement Warrants [Member] \| Common Stock [Member] \| Securities Purchase Agreement Initial Closing [Member]
Class Of Stock [Line Items]
Common stock, shares issued		8,730,168
Private Placement Warrants [Member] \| Pre-funded Warrants [Member] \| Accredited Investor [Member]
Class Of Stock [Line Items]
Warrant exercise price per share			$ 0.001
Private Placement Warrants [Member] \| Pre-funded Warrants [Member] \| Securities Purchase Agreement Initial Closing [Member]
Class Of Stock [Line Items]
Common stock, shares issued		6,421,350
Maximum [Member] \| Common Stock [Member] \| Series X Non-Voting Convertible Preferred Stock [Member]
Class Of Stock [Line Items]
Conversion of preferred stock, conversion blocker, percent					9.99%
Maximum [Member] \| Pre-funded Warrants [Member] \| Accredited Investor [Member]
Class Of Stock [Line Items]
Class of Warrant Subject to Specified Beneficial Ownership Limitations Permitted Percentage			19.99%
Maximum [Member] \| Common Stock Warrants [Member] \| Accredited Investor [Member]
Class Of Stock [Line Items]
Class of Warrant Subject to Specified Beneficial Ownership Limitations Permitted Percentage			19.99%
Minimum [Member] \| Common Stock [Member] \| Series X Non-Voting Convertible Preferred Stock [Member]
Class Of Stock [Line Items]
Conversion of preferred stock, conversion blocker, percent					9.90%
Jefferies LLC [Member] \| ATM Program [Member]
Class Of Stock [Line Items]
Common stock number of shares issued					0
Equity distribution agreement maximum value of common shares issuable				$ 75,000,000
Public float minimum balance to be maintained					$ 75,000,000
Jefferies LLC [Member] \| ATM Program [Member] \| Common Stock [Member]
Class Of Stock [Line Items]
Common stock number of shares issued				0
Jefferies LLC [Member] \| Maximum [Member] \| ATM Program [Member]
Class Of Stock [Line Items]
Equity distribution agreement maximum value of common shares issuable					$ 14,100,000
Cormorant Global Healthcare Master Fund LP [Member] \| Series X1 Non-voting Convertible Preferred Stock [Member] \| Conversion Agreement [Member]
Class Of Stock [Line Items]
Conversion of stock, shares converted	7,883.586
Cormorant Global Healthcare Master Fund LP [Member] \| Series X Non-Voting Convertible Preferred Stock [Member] \| Conversion Agreement [Member]
Class Of Stock [Line Items]
Conversion of stock, shares converted	1,782
Cormorant Global Healthcare Master Fund LP [Member] \| Common Stock [Member] \| Series X1 Non-voting Convertible Preferred Stock [Member] \| Conversion Agreement [Member]
Class Of Stock [Line Items]
Conversion of stock, shares issued	437,977
Cormorant Global Healthcare Master Fund LP [Member] \| Common Stock [Member] \| Series X Non-Voting Convertible Preferred Stock [Member] \| Conversion Agreement [Member]
Class Of Stock [Line Items]
Conversion of stock, shares issued	99,000

Fair Value Measurements (As Restated) - Additional Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($)
Warrant Liabilities [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table]
Change in fair value of warrant liabilities	$ 13,336

Document and Entity Information - shares	3 Months Ended
Document and Entity Information - shares	Mar. 31, 2024	May 10, 2024
Document Information [Line Items]
Document Type	10-Q/A
Amendment Flag	true
Amendment Description	In this Amendment No. 1 on Form 10-Q/A (“Amendment No. 1”), unless the context requires otherwise, “Eledon”, the “Company”, “we”, “our", and “us” means Eledon Pharmaceuticals, Inc. (formerly Novus Therapeutics, Inc.) and all of its wholly-owned subsidiaries.This Amendment No. 1 amends the Quarterly Report on Form 10-Q of Eledon Pharmaceuticals, Inc. for the three months ended March 30, 2024 as filed with the Securities and Exchange Commission (the “SEC”) on May 15, 2024 (the “Original Report”). On May 20, 2024, the partners and professional staff of KMJ Corbin & Company LLP (“KMJ”) departed KMJ, which was engaged as the independent registered public accounting firm of the Company and joined Crowe LLP (“Crowe”). In connection with this transition, the Audit Committee of the Board of Directors of the Company (the “Audit Committee”) dismissed KMJ as the Company's independent registered public accounting firm on July 10, 2024. On July 10, 2024, following the dismissal of KMJ, the Company, through and with the approval of its Audit Committee, appointed Crowe as its independent registered public accounting firm. In the course of preparing the Company’s unaudited condensed consolidated financial statements as of and for the three and six months ended June 30, 2024, the Company, in consultation with Crowe, determined that a correction was necessary with respect to the Company’s reporting and recording of the fair value of (i) certain common stock warrants (the “Common Warrants”) issued by the Company in May 2023 pursuant to a Securities Purchase Agreement dated as of April 28, 2023 by and among the Company and certain institutional and accredited investors (the “Securities Purchase Agreement”), and (ii) the potential issuance of pre-funded warrants in lieu of additional shares of common stock, $0.001 par value per share (the “Subsequent Closing Warrants”), issuable by the Company in a second closing and a third closing of the Securities Purchase Agreement contingent upon the satisfaction or waiver of certain specified conditions set forth therein. This correction relates to a determination that the Common Warrants and the Subsequent Closing Warrants do not meet the conditions to be classified as equity instruments under Accounting Standards Codification 815-40, “Derivatives and Hedging — Contracts in Entity’s Own Equity,” and must instead be recorded as liabilities on the Company’s consolidated balance sheet at their fair value for each reporting period.On August 13, 2024, the Company’s management and the Audit Committee concluded that the previously issued (i) audited consolidated financial statements as of and for the fiscal year ended December 31, 2023 included in the Company’s Annual Report on Form 10-K filed with the SEC on March 28, 2024 and amended by Amendment No. 1 on Form 10-K/A filed with the SEC on April 26, 2024 (together, the “2023 10-K”), and (ii) unaudited condensed consolidated financial statements as of and for (a) the three months ended March 31, 2024 included in the Original Report, (b) the three and nine months ended September 30, 2023 included in the Company’s Quarterly Report on Form 10-Q filed with the SEC on November 9, 2023 and (c) the three and six months ended June 30, 2023 included in the Company’s Quarterly Report on Form 10-Q filed with the SEC on August 10, 2023 (together, the “Impacted Reports”) were each materially misstated. As a result, the Company’s management and the Audit Committee further determined on August 13, 2024 that the Impacted Reports require restatement (the "Restatement") and should no longer be relied upon. In connection with this Restatement of the Company’s previously-filed consolidated financial statements, the Company has also determined that a material weakness existed in its internal control over financial reporting as disclosed in Item 4. Controls and Procedures of this Amendment No. 1. In addition, KMJ notified the Company on August 13, 2024 that its Report of Independent Registered Public Accounting Firm dated March 28, 2024 on the consolidated financial statements of the Company as of and for the year ended December 31, 2023 should no longer be relied on.The Company has not filed, and does not intend to file, amendments to the Quarterly Reports on Form 10-Q for the quarters ended June 30, 2023 or September 30, 2023 (the “Impacted 2023 Quarterly Reports”). Accordingly, investors should rely only on the financial information and other disclosures regarding these restated periods included in Amendment No. 2 to the 2023 Form 10-K that the Company has filed with the SEC. The financial information that has been previously filed or otherwise reported for the periods covered by the Impacted Reports is superseded by the information in Amendment No. 2 to the 2023 Form 10-K (as to the fiscal year ended December 31, 2023 and, solely with respect to the information included under the caption “Restatement of Interim Financial Information” in Note 13 of the Notes to Consolidated Financial Statements included in Amendment No. 2 to the 2023 Form 10-K, as to the information included in the Impacted 2023 Quarterly Reports), as well as by this Amendment No. 1 (as to the three months ended March 31, 2024 included in the Original Report), as applicable. The errors did not result in any impact on the Company’s cash and short-term investment position, cash runway, or operations.This Amendment No. 1 presents the Original Report, as amended and restated to date, with further modifications as necessary to reflect the Restatement. The following items have been amended to reflect the Restatement:•Item 1. Financial Information•Item 2. Management’s discussion and analysis of financial condition and results of operations.•Item 4. Controls and Procedures•Item 1A. Risk FactorsIn addition, in accordance with Rule 12b-15 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), Item 6 of Part II of the Original Report is being amended and restated solely to include as exhibits the certifications of our principal executive officer and principal financial officer required by Rule 13a-14(a) under the Exchange Act and Section 1350 of Chapter 63 of Title 18 of the United States Code (18 U.S.C. 1350). Except as otherwise expressly noted herein, this Amendment No. 1 does not amend, modify or update any other information set forth in the Original Report. Furthermore, this Amendment No. 1 does not change any previously reported financial results, except as necessary to reflect the Restatement, nor does it reflect events occurring after the filing date of the Original Report. Information not affected by this Amendment No. 1 remains unchanged and reflects the disclosures made at the time the Original Report was filed. Accordingly, this Amendment No. 1 should be read in conjunction with our filings made with the SEC subsequent to the filing of the Original Report, including any amendment to those filings.
Document Period End Date	Mar. 31, 2024
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1
Trading Symbol	ELDN
Entity Registrant Name	ELEDON PHARMACEUTICALS, INC.
Entity Central Index Key	0001404281
Entity Current Reporting Status	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Shell Company	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		38,506,614
Entity File Number	001-36620
Entity Tax Identification Number	20-1000967
Entity Address, Address Line One	19800 MacArthur Blvd
Entity Address, Address Line Two	Suite 250
Entity Address, City or Town	Irvine
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92612
City Area Code	(949)
Local Phone Number	238-8090
Document Quarterly Report	true
Document Transition Report	false
Entity Incorporation, State or Country Code	DE
Title of 12(b) Security	Common Stock, $0.001 par value
Security Exchange Name	NASDAQ
Entity Interactive Data Current	Yes
Former Address [Member]
Document Information [Line Items]
Entity Address, Address Line One	19900 MacArthur Boulevard
Entity Address, Address Line Two	Suite 550
Entity Address, City or Town	Irvine
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92612

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Operating expenses
Research and development	$ 7,410	$ 8,113
General and administrative	3,459	2,997
Total operating expenses	10,869	11,110
Loss from operations	(10,869)	(11,110)
Other income, net	574	338
Change in fair value of warrant liabilities and fair value of financial instruments issued in excess of proceeds	(13,336)
Net loss and comprehensive loss	$ (23,631)	$ (10,772)
Net loss per share, Basic	$ (0.79)	$ (0.75)
Net loss per share, Diluted	$ (0.79)	$ (0.75)
Weighted-average common shares outstanding, Basic	29,989,400	14,285,905
Weighted Average Number of Shares Outstanding, Diluted	29,989,400	14,285,905

Commitments and Contingencies - Schedule of Other Information Related to Leases (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 102	$ 83
Remaining lease term
Operating leases	8 months 12 days	1 year 8 months 12 days
Discount rate
Operating leases	2.47%	2.49%

Net Loss Per Share - Summary of Common Share Equivalents were excluded because the Inclusion is Anti-dilutive (Detail) - shares	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	34,174,075	10,238,199
Stock Options Outstanding and Other Equity Awards [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	15,596,742	6,812,385
Common and Preferred Warrants Outstanding [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	18,577,333	3,425,814

Summary of Significant Accounting Policies - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2024
Summary Of Significant Accounting Policies [Line Items]
Cash, cash equivalents and restricted cash, maturity period	three months or less
Accounting Standards Update 2023-09 [Member]
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted	true
Accounting Standards Update 2023-07 [Member]
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted	true
Anelixis Therapeutics, LLC and Otic Pharma, Ltd.
Summary Of Significant Accounting Policies [Line Items]
Ownership interest percentage	100.00%
Otic Pharma, Inc. [Member]
Summary Of Significant Accounting Policies [Line Items]
Ownership interest percentage	100.00%

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash flows used in operating activities:
Net Income (Loss)	$ (23,631)	$ (10,772)
Adjustments to reconcile net loss to net cash used in operating activities:
Amortization of operating lease asset	95	92
Accretion on investment discounts	(500)
Stock-based compensation	1,694	1,381
Change in fair value of warrant liabilities and fair value of financial instruments issued in excess of proceeds	13,336
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(87)	471
Accounts payable, accrued expenses and other liabilities	451	(1,018)
Operating lease liabilities	(99)	(78)
Net cash used in operating activities	(8,741)	(9,924)
Cash flows from investing activities:
Purchase of available-for-sale short-term investments	(12,917)
Proceeds from maturities of available-for-sale short-term investments	22,700
Net cash provided by investing activities	9,783
Cash flows from financing activities:
Proceeds from issuances of common stock and pre-funded warrants, net	1
Net cash provided by financing activities	1
Net change in cash and cash equivalents	1,043	(9,924)
Cash and cash equivalents at beginning of period	4,612	56,409
Cash and cash equivalents at end of period	$ 5,655	$ 46,485

Short-Term Investments - Summary of Short-term Investments Classified as Available-for-sale Securities (Detail) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	$ 37,207	$ 46,490
Fair Value	37,207	46,490
U.S. Government Securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	20,441	33,213
Fair Value	20,441	33,213
U.S. Government Agency Securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	16,766	13,277
Fair Value	$ 16,766	$ 13,277

Summary of Significant Accounting Policies (Policies)	3 Months Ended
Summary of Significant Accounting Policies (Policies)	Mar. 31, 2024
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with GAAP and Article 8 of Regulation S-X requirements as set forth by the Securities and Exchange Commission (“SEC”) for interim financial information and reflect all adjustments and disclosures, which are, in the opinion of management, of a normal and recurring nature, and considered necessary for a fair presentation of the financial information contained herein. Pursuant to these rules and regulations, the unaudited condensed consolidated financial statements do not include all information and notes necessary for a complete presentation of results of operations and comprehensive loss, financial position, and cash flows in conformity with GAAP. The accompanying unaudited condensed consolidated financial statements and notes should be read in conjunction with the audited financial statements and accompanying notes of Eledon for the year ended December 31, 2023 included in the Company's Annual Report on Form 10-K filed by the Company with the SEC on March 28, 2024, as amended on each of April 26, 2024 and Augsut 19, 2024 (together, the "Amended Form 10K"). The results of operations and comprehensive loss for the three months ended March 31, 2024 are not necessarily indicative of results expected for the full fiscal year or any other future period.
Principles of Consolidation	Principles of Consolidation Eledon, a Delaware corporation, owns 100% of the issued and outstanding common stock or other ownership interest in Anelixis Therapeutics, LLC, a Delaware limited liability company, and Otic Pharma, Ltd., a private limited company organized under the laws of the State of Israel (“Otic”). Otic owns 100% of the issued and outstanding common stock or other ownership interest in its U.S. subsidiary, Otic Pharma, Inc. The functional currency of the Company’s foreign subsidiary is the U.S. Dollar; however, certain expenses, assets and liabilities are transacted at the local currency. These transactions are translated from the local currency into U.S. Dollars at exchange rates during or at the end of the reporting period. The activities of the Company’s foreign subsidiary are not significant to the condensed consolidated financial statements. All significant intercompany accounts and transactions among the entities have been eliminated from the condensed consolidated financial statements.
Use of Estimates	Use of Estimates The preparation of the Company’s consolidated financial statements in conformity with GAAP requires management to make informed estimates and assumptions that affect the reported amounts of assets, liabilities and expenses and the disclosure of contingent assets and liabilities in the Company’s consolidated financial statements and accompanying notes. The most significant estimates in the Company’s consolidated financial statements relate to stock-based compensation expense, warrant liabilities, the fair value of right-of-use assets and liabilities, accruals for liabilities, impairment of long-lived assets, and other matters that affect the consolidated financial statements and related disclosures. Management bases its estimates on historical experience and on various other market-specific and relevant assumptions that management believes to be reasonable under the circumstances. Actual results could differ materially from those estimates under different assumptions or conditions and the differences may be material to the consolidated financial statements.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments which potentially subject the Company to significant concentration of credit risk consists of cash, cash equivalents and short-term investments. The Company maintains deposits in federally insured institutions in excess of federally insured limits and invests in short-term investments with the primary objective of seeking to preserve principal, achieve liquidity requirements and safeguard invested funds. We believe that the Company is not exposed to significant credit risk due to the financial position of the depository institution in which those deposits are held and the nature, including the credit ratings, of our cash equivalents and short-term investments, but we have not eliminated all credit risk.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with original maturities of three months or less when purchased to be cash equivalents. Cash and cash equivalents include cash in readily available checking accounts, money market funds, U.S. government securities and U.S. government agency securities. The carrying amounts reported in the unaudited condensed consolidated balance sheets for cash and cash equivalents are valued at cost, which approximates their fair value due to the short-term maturities of these investments.
Risks and Uncertainties	Risks and Uncertainties As of March 31, 2024 and December 31, 2023, all of the Company’s long-lived assets were located in the United States. The Company’s products will require approval from the U.S. Food and Drug Administration (“FDA”) and foreign regulatory agencies before commercial sales can commence. There can be no assurance that its products will receive any of these required approvals. The denial or delay of such approvals may impact the Company’s business in the future. In addition, after the approval by the FDA, there is still an ongoing risk of adverse events that did not appear during the product approval process. The Company is subject to risks common to companies in the pharmaceutical industry, including, but not limited to, new technological innovations, clinical development risk, establishment of appropriate commercial partnerships, protection of proprietary technology, compliance with government and environmental regulations, uncertainty of market acceptance of products, product liability, the volatility of its stock price and the need to obtain additional financing. The Company's facilities and equipment, including those of the Company's suppliers and vendors, may be affected by natural or man-made disasters. The Company's administrative office is based in Irvine, California and the Company manages all its research and development activities through third parties that are located throughout the world. The Company has taken precautions to safeguard its facilities, equipment and systems, including insurance, health and safety protocols, and off-site storage of computer data. However, the Company's facilities and systems, as well as those of its third-party suppliers and vendors, may be vulnerable to earthquakes, fire, storm, public health or similar emergencies, power loss, telecommunications failures, physical and software break-ins, software viruses and similar events which could cause substantial delays in its operations, damage or destroy its equipment or inventory, and cause the Company to incur additional expenses and delay research and development activities. In addition, the insurance coverage the Company maintains may not be adequate to cover its losses in any circumstance and may not continue to be available to use on acceptable terms, or at all.
In-Process Research and Development	In-Process Research and Development The fair values of in-process research and development (“IPR&D”) projects acquired in a business combination that are not complete are capitalized and accounted for as indefinite-lived intangible assets until completion or abandonment of the related research and development (“R&D”) efforts. Upon successful completion of the project, the capitalized amount is amortized over its estimated useful life. If a project is abandoned, all remaining capitalized amounts are written off immediately. Major risks and uncertainties are often associated with IPR&D projects because we are required to obtain regulatory approvals before marketing the resulting products. Such approvals require completing clinical trials that demonstrate a product candidate is safe and effective. Consequently, the eventual realized value of the acquired IPR&D project may vary from its fair value at the date of acquisition, and IPR&D impairment charges may occur in future periods. Capitalized IPR&D projects are tested for impairment annually and whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. We consider various factors for potential impairment, including the current legal and regulatory environment and the competitive landscape. Adverse clinical trial results, significant delays in obtaining marketing approval, the inability to bring a product to market and the introduction or advancement of competitors’ products could result in partial or full impairment of the related intangible assets.
Research and Development Expenses	Research and Development Expenses Research and development expenses include personnel and facility-related expenses, outside contracted services including clinical trial costs, manufacturing and process development costs, research costs and other consulting services and non-cash stock-based compensation. Research and development costs are expensed as incurred. Amounts due under contracts with third parties may be either fixed fee or fee for service, and may include upfront payments, monthly payments and payments upon the completion of milestones or receipt of deliverables. Non-refundable advance payments under agreements are capitalized and expensed as the related goods are delivered or services are performed. The Company contracts with third parties to perform various clinical trial activities in the on-going development of potential products. The financial terms of these agreements are subject to negotiation, vary from contract to contract and may result in uneven payment flows to its vendors. Payments under the contracts depend on factors such as the achievement of certain events, successful enrollment of patients, and completion of portions of the clinical trial or similar conditions. The Company’s accrual for clinical trials is based on estimates of the services received and efforts expended pursuant to contracts with clinical trial centers and clinical research organizations. These contracts may be terminated by the Company upon written notice and the Company is generally only liable for actual effort expended by the organizations to the date of termination, although in certain instances the Company may be further responsible for termination fees and penalties. The Company estimates its research and development expenses and the related accrual as of each balance sheet date based on the facts and circumstances known to the Company at that time. There have been no material adjustments to the Company’s prior‑period accrued estimates for clinical trial activities during the three months ended March 31, 2024.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In December 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures. This update requires disaggregated information about a reporting entity’s effective tax rate reconciliation as well as information on income taxes paid. ASU No. 2023-09 is effective for public entities with annual periods beginning after December 15, 2024, with early adoption permitted. The Company is currently evaluating the impact of this guidance on its consolidated financial statements. In November 2023, the FASB issued ASU No. 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures. This update requires public entities to disclose information about their reportable segments’ significant expenses and other segment items on an interim and annual basis. Public entities with a single reportable segment are required to apply the disclosure requirements in ASU 2023-07, as well as all existing segment disclosures and reconciliation requirements in ASC 280, on an interim and annual basis. ASU 2023-07 is effective for fiscal years beginning after December 15, 2023 and for interim periods beginning after December 15, 2024, with early adoptions permitted. The Company is currently evaluating the impact of this guidance on its consolidated financial statements. Other recent accounting pronouncements issued by the FASB (including its Emerging Issues Task Force), the American Institute of Certified Public Accountants, and the SEC did not, or are not believed by management to, have a material impact on the Company’s present or future financial position, results of operations or cash flows.
Warrant Liabilities	Warrant Liabilities The Company accounts for issued warrants either as a liability or equity in accordance with ASC 815-40. Under ASC 815-40, contracts that may require settlement for cash are liabilities, regardless of the probability of the occurrence of the triggering event. Liability-classified warrants are measured at fair value on the issuance date and at the end of each reporting period. Any change in the fair value of the warrants after the issuance date is recorded in the condensed consolidated statements of operations and comprehensive loss as a gain or loss. If warrants do not require liability classification under ASC 815-40, in order to conclude warrants should be classified as equity, the Company assesses whether the warrants are indexed to its common stock and whether the warrants are classified as equity under ASC 815-40 or other applicable GAAP standard. Equity-classified warrants are accounted for at fair value on the issuance date with no changes in fair value recognized after the issuance date.

Restatement of Previously Issued Consolidated Financial Statements - Summary of Impact of Correction of Misstatements - Corrected Condensed Consolidated Statements of Stockholders' Equity (Deficit) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Beginning Balance	$ 7,208	$ 84,183
Issuance of common stock in connection with exercise of pre-funded warrants, Value	1
Stock-based compensation	1,694	1,381
Net loss and comprehensive loss	(23,631)	(10,772)
Ending Balance	(14,728)	74,792
Accumulated Deficit [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Beginning Balance	(319,402)	(202,865)
Net loss and comprehensive loss	(23,631)	(10,772)
Ending Balance	(343,033)	$ (213,637)
As Previously Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Beginning Balance	83,419
Issuance of common stock in connection with exercise of pre-funded warrants, Value	1
Stock-based compensation	1,694
Net loss and comprehensive loss	(10,295)
Ending Balance	74,819
As Previously Reported [Member] \| Accumulated Deficit [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Beginning Balance	(243,191)
Net loss and comprehensive loss	(10,295)
Ending Balance	(253,486)
Restatement Impact [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Beginning Balance	(76,211)
Net loss and comprehensive loss	(13,336)
Ending Balance	(89,547)
Restatement Impact [Member] \| Accumulated Deficit [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Beginning Balance	(76,211)
Net loss and comprehensive loss	(13,336)
Ending Balance	$ (89,547)

Accrued Expenses and Other Liabilities - Schedule of Accrued Expenses and Other Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Accrued Liabilities and Other Liabilities [Abstract]
Accrued compensation and related expenses	$ 969	$ 2,003
Accrued clinical	948	451
Accrued professional services	132	47
Accrued other	50	44
Total accrued expenses and other liabilities	$ 2,099	$ 2,545

Fair Value Measurements (As Restated) - Schedule of Financial Instruments Measured At Fair Value On A Recurring Basis (Detail) - Fair Value, Recurring [Member] - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	$ 4,098	$ 4,246
Total short-term investments	37,207	46,490
Total financial assets	41,305	50,736
Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	4,098	4,246
U.S. Government Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	20,441	33,213
U.S. Government Agency Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	16,766	13,277
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	4,098	4,246
Total financial assets	4,098	4,246
Fair Value, Inputs, Level 1 [Member] \| Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	4,098	4,246
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	37,207	46,490
Total financial assets	37,207	46,490
Fair Value, Inputs, Level 2 [Member] \| U.S. Government Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	20,441	33,213
Fair Value, Inputs, Level 2 [Member] \| U.S. Government Agency Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	$ 16,766	$ 13,277

Stock-Based Compensation - Additional Information (Detail) - shares			3 Months Ended
	Jun. 21, 2023	May 01, 2023	Mar. 31, 2024
Time-based and Performance-based Vesting Requirements [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted		7,381,857
Stock options granted		5,905,485
Time-based Vesting Requirements [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted		1,476,372
2014 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, number of shares reserved for issuance			0
2020 Long Term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, number of shares reserved for issuance			2,813,742
Increased number of shares	9,600,000
New aggregate share limit	14,460,000
2014 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, number of shares reserved for issuance			24,077
Employee Stock Option [Member] \| Board of Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life assumption using simplified method, description			For stock options granted to the Company’s board of directors (the “Board”), the Company determined the expected life assumption using the simplified method as the starting point with an average period of twelve (12) months added to take into account the extended range of time of 12 to 18 months that vested stock options granted to Board members may be exercised upon termination.
Employee Stock Option [Member] \| Board of Directors [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of stock options granted			12 months
Employee Stock Option [Member] \| Board of Directors [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of stock options granted			18 months

Condensed Consolidated Statements of Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]	Series X1 Non-voting Convertible Preferred Stock [Member]	Series X Non-Voting Convertible Preferred Stock [Member]
Beginning Balance at Dec. 31, 2022	$ 84,183	$ 14	$ 287,034	$ (202,865)
Beginning Balance, Shares at Dec. 31, 2022		13,776,788			117,970	6,204
Stock-based compensation	1,381		1,381
Net loss and comprehensive loss	(10,772)			(10,772)
Ending Balance at Mar. 31, 2023	74,792	$ 14	288,415	(213,637)
Ending Balance, Shares at Mar. 31, 2023		13,776,788			117,970	6,204
Beginning Balance at Dec. 31, 2023	7,208	$ 24	326,586	(319,402)
Beginning Balance, Shares at Dec. 31, 2023		24,213,130			110,086	4,422
Issuance of common stock in connection with exercise of pre-funded warrants, Shares		600,000
Issuance of common stock in connection with exercise of pre-funded warrants, Value	1	$ 1
Stock-based compensation	1,694		1,694
Net loss and comprehensive loss	(23,631)			(23,631)
Ending Balance at Mar. 31, 2024	$ (14,728)	$ 25	$ 328,280	$ (343,033)
Ending Balance, Shares at Mar. 31, 2024		24,813,130			110,086	4,422

Net Loss Per Share - Schedule of Common Share Equivalents Included from Computation of Net Loss Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Earnings Per Share [Abstract]
Net Income (Loss)	$ (23,631)	$ (10,772)
Net loss per share, basic	$ (0.79)	$ (0.75)
Net loss per share, diluted	$ (0.79)	$ (0.75)
Weighted-average number of common shares, basic	29,989,400	14,285,905
Weighted-average number of common shares, diluted	29,989,400	14,285,905

Subsequent Events - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	May 06, 2024	May 09, 2024	May 07, 2024	Mar. 31, 2024	Jan. 30, 2024	Dec. 31, 2023	Nov. 06, 2023	Nov. 02, 2023	Jul. 14, 2023	Jul. 10, 2023	Apr. 28, 2023
Subsequent Event [Line Items]
Common stock, shares issued				24,813,130		24,213,130
Common stock, par value				$ 0.001		$ 0.001
Armistice Capital Master Fund Ltd [Member] \| Securities Purchase Agreement [Member]
Subsequent Event [Line Items]
Common stock, shares issued					600,000		653,000		501,197
Warrant exercise price					$ 0.001			$ 0.001		$ 0.001
Number of pre-funded warrants exercised for common stock					600,000			653,000		501,197
Subsequent Event [Member] \| Armistice Capital Master Fund Ltd [Member] \| Securities Purchase Agreement [Member]
Subsequent Event [Line Items]
Common stock, shares issued		583,000
Warrant exercise price			$ 0.001
Number of pre-funded warrants exercised for common stock			583,000
Accredited Investor [Member] \| Private Placement [Member]
Subsequent Event [Line Items]
Warrant exercise price											$ 3
Accredited Investor [Member] \| Pre-funded Warrants [Member] \| Private Placement [Member]
Subsequent Event [Line Items]
Warrant exercise price											$ 0.001
Accredited Investor [Member] \| Subsequent Event [Member] \| Securities Purchase Agreement [Member] \| Private Placement [Member]
Subsequent Event [Line Items]
Common stock, shares issued	13,110,484
Common stock, par value	$ 0.001
Stock price per share	$ 2.37
Net proceeds after deducting offering costs	$ 47.6
Gross proceeds	$ 50.0
Accredited Investor [Member] \| Subsequent Event [Member] \| Pre-funded Warrants [Member] \| Securities Purchase Agreement [Member] \| Private Placement [Member]
Subsequent Event [Line Items]
Stock price per share	$ 2.369
Common stock warrants exercisable	7,989,516
Warrant exercise price	$ 0.001
Warrants beneficial ownership limitation percentage	9.99%
Minimum [Member] \| Accredited Investor [Member] \| Subsequent Event [Member] \| Pre-funded Warrants [Member] \| Securities Purchase Agreement [Member] \| Private Placement [Member]
Subsequent Event [Line Items]
Warrants beneficial ownership limitation percentage	4.99%
Maximum [Member] \| Accredited Investor [Member] \| Subsequent Event [Member] \| Pre-funded Warrants [Member] \| Securities Purchase Agreement [Member] \| Private Placement [Member]
Subsequent Event [Line Items]
Warrants beneficial ownership limitation percentage	19.99%

Prepaid Expenses and Other Current Assets - Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid insurance	$ 441	$ 624
Prepaid clinical	4,211	4,128
Prepaid other	409	185
Other current assets	54	90
Total prepaid expenses and other current assets	$ 5,115	$ 5,027

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 5,655	$ 4,612
Short-term investments	37,207	46,490
Prepaid expenses and other current assets	5,115	5,027
Total current assets	47,977	56,129
Operating lease asset, net	270	365
In-process research and development	32,386	32,386
Other assets	185	186
Total assets	80,818	89,066
Current liabilities:
Accounts payable	1,864	967
Current operating lease liabilities	284	383
Accrued expenses and other liabilities	2,099	2,545
Total current liabilities	4,247	3,895
Deferred tax liabilities	1,752	1,752
Warrant liabilities	89,547	76,211
Total liabilities	95,546	81,858
Commitments and contingencies (Note 8)
Stockholders equity (deficit):
Common stock, $0.001 par value, 200,000,000 shares authorized at March 31, 2024 and December 31, 2023; 24,813,130 and 24,213,130 shares issued and outstanding at March 31, 2024 and December 31, 2023, respectively	25	24
Additional paid-in capital	328,280	326,586
Accumulated deficit	(343,033)	(319,402)
Total stockholders equity (deficit)	(14,728)	7,208
Total liabilities and stockholders equity (deficit)	80,818	89,066
Series X1 Non-voting Convertible Preferred Stock [Member]
Stockholders equity (deficit):
Preferred stock, value
Series X Non-voting Convertible Preferred Stock [Member]
Stockholders equity (deficit):
Preferred stock, value

Stock-Based Compensation - Schedule of Stock-Based Compensation Expense Recognized (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation	$ 1,694	$ 1,381
Research and Development [Member]
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation	349	397
General and Administrative [Member]
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation	$ 1,345	$ 984

Net Loss Per Share - Additional Information (Detail) - Pre-funded Warrants [Member] - $ / shares	Mar. 31, 2024	Mar. 31, 2023
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Common stock warrants exercisable	5,176,270	509,117
Warrant exercise price	$ 0.001