Eloxx Pharmaceuticals (ELOX) 10-K 31 Mar 23 2022 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Mar. 27, 2023	Jun. 30, 2022
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Trading Symbol	ELOX
Entity Registrant Name	ELOXX PHARMACEUTICALS, INC.
Entity Central Index Key	0001035354
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding			2,166,356
Entity Public Float				$ 16,650,960
Entity Small Business	true
Entity Emerging Growth Company	false
Entity File Number	001-31326
Entity Tax Identification Number	84-1368850
Entity Address, Address Line One	480 Arsenal Way
Entity Address, City or Town	Watertown
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02472
City Area Code	781
Local Phone Number	577-5300
ICFR Auditor Attestation Flag	false
Entity Shell Company	true
Document Annual Report	true
Document Transition Report	false
Entity Incorporation, State or Country Code	DE
Title of 12(b) Security	Common Stock, $0.01 par value
Security Exchange Name	NASDAQ
Entity Interactive Data Current	Yes
Auditor Name	Baker Tilly US, LLP	Deloitte & Touche LLP
Auditor Location	Tewksbury, Massachusetts	Boston, Massachusetts
Auditor Firm ID	23	34
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE Certain information required by Part III, Items 10-14 of this Form 10-K is incorporated by reference to the Registrant’s definitive Proxy Statement for the 2022 Annual Meeting of Stockholders to be filed with the Securities and Exchange Commission pursuant to Regulation 14A not later than 120 days after the end of the fiscal year covered by this Form 10-K, provided that if such Proxy Statement is not filed within such period, such information will be included in an amendment to this Form 10-K to be filed within such 120-day period.

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 19,207	$ 42,268
Restricted cash	261	299
Prepaid expenses and other current assets	661	913
Total current assets	20,129	43,480
Property and equipment, net	169	216
Operating lease right-of-use asset	825	1,443
Total assets	21,123	45,139
Current liabilities:
Accounts payable	3,020	1,379
Accrued expenses	2,799	4,196
Current portion of long-term debt	3,980	0
Advances from collaboration partners	12,535	3,723
Current portion of operating lease liability	712	657
Derivative liabilities	45	0
Total current liabilities	23,091	9,955
Long-term debt	8,557	11,996
Operating lease liability	135	804
Total liabilities	31,783	22,755
Commitments and contingencies
Stockholders (Deficit) equity:
Preferred stock, $0.01 par value per share, 5,000,000 shares authorized, no shares issued or outstanding as of December 31, 2022 and 2021	0	0
Common stock, $0.01 par value per share, 500,000,000 shares authorized, 2,166,356 and 2,176,782 shares issued, and 2,166,356 and 2,166,247 shares outstanding as of December 31, 2022 and 2021, respectively	22	22
Common stock in treasury, at cost, 0 and 10,535 shares as of December 31, 2022 and 2021, respectively	0	(2,190)
Additional paid-in capital	263,706	262,875
Accumulated deficit	(274,388)	(238,323)
Total stockholders’ equity	(10,660)	22,384
Total liabilities and stockholders’ equity	$ 21,123	$ 45,139

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.01	$ 0.01
Preferred Stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred Stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	2,166,356	2,176,783
Common stock, shares outstanding	2,166,356	2,166,248
Common stock, treasury shares	0	10,535

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Operating expenses:
Research and development	$ 23,727	$ 22,899
General and administrative	10,692	20,449
In process research and development	0	22,670
Total operating expenses	34,419	66,018
Loss from operations	(34,419)	(66,018)
Other expense, net	1,646	709
Net loss	$ (36,065)	$ (66,727)
Net loss per share, basic	$ (16.65)	$ (38.15)
Net loss per share, diluted	$ (16.65)	$ (38.15)
Weighted average number of shares of common stock used in computing net loss per share, basic	2,166,311	1,749,071
Weighted average number of shares of common stock used in computing net loss per share, diluted	2,166,311	1,749,071

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Public Offering [Member]	Common Stock [Member]	Common Stock [Member] Public Offering [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] Public Offering [Member]	Treasury stock [Member]	Accumulated deficit [Member]
Balance at Dec. 31, 2020	$ 10,230		$ 10		$ 183,644		$ (1,828)	$ (171,596)
Balance, shares at Dec. 31, 2020			1,003,930				(4,844)
Balance, shares at Dec. 31, 2021	2,166,248		2,166,248				(10,535)
Exercise of stock options	$ 23				23
Exercise of stock options, shares			587
Issuance of common stock in connection with merger	22,335		$ 2		22,333
Issuance of common stock in connection with merger, shares			189,920
Issuance of shares upon public offering, net of offering costs		$ 47,718		$ 10		$ 47,708
Issuance of shares upon public offering, net of offering costs, shares				958,333
Vesting of restricted stock units	(362)						$ (362)
Vesting of restricted stock units, shares			13,478				(5,691)
Stock-based compensation expense	9,167				9,167
Net loss	(66,727)							(66,727)
Balance at Dec. 31, 2021	$ 22,384		$ 22		262,875		$ (2,190)	(238,323)
Balance, shares at Dec. 31, 2022	2,166,356		2,166,356				0
Exercise of stock options, shares	0
Vesting of restricted stock units, shares			157
Stock-based compensation expense	$ 3,021				3,021
Retirement of treasury stock					(2,190)		$ 2,190
Retirement of treasury stock, shares							$ 10,535
Effect of reverse stock split, shares			$ (49)
Net loss	(36,065)							(36,065)
Balance at Dec. 31, 2022	$ (10,660)		$ 22		$ 263,706		$ 0	$ (274,388)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities:
Net loss	$ (36,065)	$ (66,727)
Adjustments to reconcile net loss to net cash used in operating activities:
Acquired in-process research and development	0	22,670
Stock-based compensation	3,021	9,167
Depreciation	77	114
Impairment of property and equipment	36	0
Amortization of operating lease right-of-use asset	618	846
Amortization of debt discount	541	420
Loss (gain) on sales and disposals of property and equipment	0	84
Change in fair value of embedded derivative liabilities	45	0
Gain on extinguishment of PPP debt	0	(808)
Loss on extinguishment of term debt	0	268
Changes in operating assets and liabilities:
Prepaid expenses and other assets	252	582
Accounts payable	1,641	(320)
Accrued expenses	(1,397)	535
Merger related costs paid	0	(1,003)
Operating lease liabilities	(614)	(829)
Net cash used in operating activities	(31,845)	(35,001)
Cash flows from investing activities:
Cash acquired in merger activities	0	2,145
Purchase of property and equipment	(66)	(89)
Net cash (used in) provided by investing activities	(66)	2,056
Cash flows from financing activities:
Proceeds from advances from collaboration partners	8,812	2,918
Proceeds from underwritten public offering, net of issuance costs	0	47,718
Proceeds from debt financing obligation	0	11,874
Repayment of term loan principal	0	(11,383)
Proceeds from exercises of stock options	0	23
Payment for settlement of taxes upon vesting of restricted stock units	0	(362)
Net cash provided by financing activities	8,812	50,788
Increase (decrease) in cash, cash equivalents and restricted cash	(23,099)	17,843
Cash, cash equivalents and restricted cash at the beginning of the year	42,567	24,724
Cash, cash equivalents and restricted cash at the end of the year	19,468	42,567
Reconciliation of cash, cash equivalents and restricted cash to consolidated balance sheet:
Cash and cash equivalents	19,207	42,268
Restricted cash	261	299
Cash, cash equivalents and restricted cash at the end of the year	19,468	42,567
Supplemental disclosure of cash flow activities:
Cash paid for interest	1,365	728
Supplemental disclosure of non-cash financing activities:
Right-of-use assets obtained in exchange for lease liabilities	$ 64	$ 0

Nature of the Business

Nature of the Business	12 Months Ended
	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of the Business	1. Nature of the Business Eloxx Pharmaceuticals, Inc., together with its subsidiaries (collectively “Eloxx” or the “Company”), is a clinical-stage biopharmaceutical company engaged in the science of ribosomal modulation. The Company is developing novel small molecule drug candidates from its library of unique Ribosome Modulating Agents (“RMAs”) and Eukaryotic Ribosomal Selective glycosides (“ERSGs”), for the treatment of a subset of rare and ultra-rare diseases and cancers characterized by genetic mutations that cause defects in protein translation. Specifically, the Company is targeting restoration of functional proteins in patients with premature stop codon mutations and ribosomal mutations. Premature stop codons are point mutations that disrupt the stability of the impacted messenger RNA (mRNA) and the protein synthesis from that mRNA. Additionally, certain mutations of the ribosome disrupt normal protein translation and are drivers of a subset of cancers. On April 1, 2021, the Company acquired Zikani Therapeutics, Inc. (“Zikani”), a preclinical stage biopharmaceutical company engaged in the science of ribosome modulation, leveraging its innovative TURBO-ZM TM chemistry technology platform to develop novel ribosome modulating agents (“RMAs”). The TURBO-ZM TM platform is designed to enable rapid synthesis of novel macrolides that can be optimized to modulate the human, bacterial or viral ribosomes to treat rare diseases and cancers with certain ribonucleic acid (“RNA”) and ribosomal mutations. On December 1, 2022, the Company effected a 1-for-40 reverse split of its common stock (the "Reverse Stock Split"). Proportional adjustments for the Reverse Stock Split were made to the Company's outstanding stock options, warrants, and equity incentive plans. All share and per-share data and amounts have been retroactively adjusted as of the earliest period presented in the consolidated financial statements to reflect the Reverse Stock Split. In conjunction with the Reverse Stock Split, the Company cancelled all shares of treasury stock. The Company is headquartered in Watertown, Massachusetts, with additional operations in Israel and Australia. Liquidity and Going Concern The Company has a history of net losses and negative cash flows from operating activities since inception, and as of December 31, 2022 , had an accumulated deficit of $ 274.4 million. The Company expects to continue to incur net losses and negative cash flows from its operations for the foreseeable future. The Company has not generated revenue from the sale of any product or service and does not expect to generate significant revenue unless it obtains marketing approval for and commercializes one or more of its product candidates currently in development. Successful transition to profitable operations is dependent upon achieving a level of revenue adequate to support the Company’s cost structure. The Company has financed its operations primarily from the sale of equity securities and to a lesser extent, loans and grants. The Company may never achieve profitability, and unless and until it does, the Company will continue to need to raise additional capital to fund its operations. In addition, as disclosed in Note 7, in September 2021, the Company entered into the Hercules Term Loan (as defined below) for an aggregate principal amount of $ 30.0 million of which $ 12.5 million had been funded as of December 31, 2022. The second tranche of $ 7.5 million expired August 15, 2022 and the third tranche of $ 10.0 million is only available at the sole discretion of Hercules' investment committee. The Hercules Term Loan Agreement contains customary affirmative and negative covenants, which among others further described in Note 7, require the Company to maintain at all times a minimum qualified cash balance ranging from $ 6.3 million to $ 10.0 million ($ 10.0 million effective as of August 15, 2022 and as of December 31, 2022) plus qualified accounts payable (as defined in the Hercules Term Loan Agreement). Subsequent to year end, on March 7, 2023, the Company repaid $ 7.5 million of principal and the minimum qualified cash balance debt covenant was decreased to $ 2.25 million as of March 7, 2023, and may be further reduced to $ 0 if the Company has raised $ 20.0 million in equity investments prior to May 31, 2023. As of December 31, 2022, the Company was in compliance with all debt covenants. However, the inherent uncertainties described above may impact the Company’s ability to remain in compliance with these covenants over the next 12 months. If the Company breaches its financial covenants and fails to secure a waiver or forbearance from the third-party lender, such breach or failure could accelerate the repayment of the outstanding borrowings under the Hercules Term Loan Agreement or the exercise of other rights or remedies the third-party lender may have under applicable law. No assurance can be provided a waiver or forbearance will be granted or the outstanding borrowings under the Hercules Term Loan Agreement, will be successfully refinanced on terms that are acceptable to the Company. The Company believes that its cash and cash equivalents of $ 19.2 million at December 31, 2022 will not be sufficient to maintain its current and planned operations for at least the next twelve months following the filing of this Annual Report on Form 10-K. The accompanying consolidated financial statements have been prepared assuming that the Company will continue as a going concern, which contemplates the realization of assets and settlement of liabilities in the normal course of business. However, based on the Company’s current working capital, anticipated operating expenses and net losses and the uncertainties surrounding its ability to raise additional capital as needed, as discussed below, the Company believes that these conditions, in aggregate, raise substantial doubt about its ability to continue as a going concern for one year after the date these consolidated financial statements are issued. Management intends to fund future operations through private or public debt or equity financing transactions and may seek additional capital through arrangements with strategic partners or from other sources. The availability of sufficient funding to alleviate the conditions that raise substantial doubt are not within management’s control and cannot be assessed as being probable of occurring. If the Company is unable to obtain adequate financing, it will evaluate options which may include reducing or deferring operating expenses, which may have a material adverse effect on the Company’s operations and future prospects.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The Company has prepared its consolidated financial statements in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASUs”) promulgated by the Financial Accounting Standards Board (“FASB”). Reverse Stock Split On December 1, 2022, the Company effected a 1-for-40 reverse stock split of its common stock (the “Reverse Stock Split”). As further described below, at a special meeting of stockholders held on November 30, 2022 (the “Special Meeting”), the stockholders of the Company approved a proposal to authorize the Company’s Board of Directors, in its discretion following the Special Meeting to amend the Company’s Amended and Restated Certificate of Incorporation, as amended (the “Certificate of Incorporation”), to effect a reverse stock split of all of the outstanding shares of the Company’s common stock, par value $0.01 per share, at a ratio ranging from any whole number between 1-for-2 and 1-for-40, as determined by the Company’s Board of Directors in its discretion. On November 30, 2022, following the Special Meeting, the Company’s Board of Directors approved the Reverse Stock Split at a ratio of 1-for-40. On December 1, 2022, the Company filed with the Secretary of State of the State of Delaware a certificate of amendment to amend the Company’s Certificate of Incorporation to effect the Reverse Stock Split. The Reverse Stock Split became effective at 5:00 p.m., Eastern Time, on December 1, 2022. As a result of the Reverse Stock Split, every 40 shares of the Company’s common stock issued or outstanding were automatically reclassified into one validly issued, fully-paid and nonassessable new share of common stock, subject to the treatment of fractional shares as described below, without any action on the part of the holders. Proportionate adjustments will be made to the exercise prices and the number of shares underlying the Company’s outstanding equity awards, as applicable, and warrants exercisable for shares of common stock, as well as to the number of shares issuable under the Company’s equity incentive plans and certain existing agreements. The common stock issued pursuant to the Reverse Stock Split remain fully paid and non-assessable. The Reverse Stock Split did not affect the number of authorized shares of common stock or the par value of the common stock. No fractional shares were issued in connection with the Reverse Stock Split. Stockholders of record who would otherwise have been entitled to receive fractional shares as a result of the Reverse Stock Split received a cash payment in lieu thereof at a price equal to the fraction to which the stockholder would otherwise be entitled multiplied by the closing sales price per share of the common stock (as adjusted for the Reverse Stock Split) on The Nasdaq Capital Market on November 30, 2022, the last trading day immediately preceding the effective time of the Reverse Stock Split. All share and per share amounts in the accompanying financial statements, related footnotes, and management’s discussion and analysis have been adjusted retroactively to reflect the reverse stock split as if it had occurred at the beginning of the earliest period presented. Effective December 2, 2022, trading of the Company’s common stock on The Nasdaq Capital Market commenced on a split-adjusted basis, under the existing trading symbol “ELOX.” Principles of Consolidation The consolidated financial statements include the accounts of the Company and its subsidiaries. Intercompany balances and transactions have been eliminated upon consolidation. Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates, judgments and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. On an ongoing basis, the Company's management evaluates its estimates, which include, but are not limited to, estimates related to accrued expenses, including clinical trials and other research and development related accruals, derivative liabilities, and stock-based compensation expense. The Company bases its estimates on historical experience and other market specific or other relevant assumptions that it believes to be reasonable under the circumstances. Actual results could materially differ from those estimates. Foreign Currency The functional currency of the Company and its subsidiaries is the U.S. dollar. Accordingly, monetary accounts maintained in other currencies are re-measured into U.S. dollars in accordance with ASC Topic 830, “Foreign Currency Matters”. All foreign currency transaction gains and losses arising from transactions denominated in foreign currencies, whether realized or unrealized, are recorded in the statements of operations as other income or expenses. Cash and Cash Equivalents The Company considers all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents. The Company’s cash and cash equivalents include holdings in checking and overnight sweep accounts. The Company’s cash equivalents, which are money market funds held in a sweep account, are measured at fair value on a recurring basis. As of December 31, 2022 and 2021 the balances of cash and cash equivalents were $ 19.2 million and $ 42.3 million, respectively, which approximate fair value and were determined based upon Level 1 inputs. The sweep account is valued using quoted market prices with no valuation adjustments applied. Accordingly, these financial instruments are categorized as Level 1. Marketable Securities The Company classifies all investment instruments with an original maturity date, when purchased, in excess of three months but less than one year as current marketable securities. Marketable securities are classified as available-for-sale and are carried at fair value. The Company periodically assesses its portfolio of securities to determine whether to record any estimated allowances for credit losses in the statement of operations. This assessment includes considering whether the Company intends to sell a security, whether it is more likely than not that the Company will have to sell a security before recovery of its amortized cost, and whether a decline in a security’s fair value below its amortized cost is credit-related or non-credit-related. The Company records non-credit-related unrealized gains and losses on available-for-sale securities in accumulated other comprehensive income, which is a separate component of stockholders’ equity on its consolidated balance sheet. Gains or losses realized upon sales of available-for-sale securities are recorded in other income. The cost of securities sold is based on the specific identification method. To date, the Company has recorded no allowances for credit losses, and no realized gains or losses upon sales of securities. Restricted Cash At December 31, 2022, and 2021 , restricted cash consisted of bank guarantees related to corporate facilities leases and credit card programs. Concentrations of Credit Risk and Off-Balance Sheet Risk Financial instruments that potentially subject the Company to credit risk consist primarily of cash and cash equivalents. The Company mitigates its risk with respect to cash and cash equivalents by maintaining its deposits and investments at high-quality financial institutions. The Company invests any excess cash in money market funds and the management of these investments is not discretionary on the part of the financial institution. Substantially all of the Company's cash and cash equivalents are held at Silicon Valley Bank (SVB), and the amounts frequently exceed federally insured limits. On March 10, 2023, the Federal Deposit Insurance Corporation (FDIC) announced that SVB had been closed by the California Department of Financial Protection and Innovation. The United States Department of the Treasury announced in a joint statement with the Federal Reserve and FDIC that depositors of SVB would have access to all of their money starting March 13, 2023, including funds exceeding federally insured limits. The Company is exposed to credit risk in the event of default by the financial institutions holding its cash and cash equivalents. If the Company is unable to access its cash and cash equivalents as needed, its financial position and ability to operate its business will be adversely affected. The Company has no off-balance-sheet concentration of credit risk such as foreign exchange contracts, option contracts or other foreign hedging arrangements. Property and Equipment Property and equipment are recorded at cost, less accumulated depreciation and amortization. Leasehold improvements are amortized over the lesser of the estimated useful life or the expected term of the related lease. Costs associated with maintenance and repairs are expensed as incurred. Depreciation expense is computed on a straight-line method over the estimated useful lives of the respective assets, as follows: Estimated Useful Life Computers and software 3 years Office furniture and equipment 5 to 12 years Laboratory equipment 5 years Leasehold improvement Over the shorter of the expected remaining lease term or estimated useful life Upon sale or disposition of property and equipment, the cost and related accumulated depreciation and amortization are eliminated from the accounts and any resultant gain or loss is credited or charged to operations. Impairment of Long-Lived Assets Property and equipment subject to depreciation are reviewed for impairment in accordance with ASC Topic 360, “Accounting for the Impairment or Disposal of Long-Lived Assets,” whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If such assets are considered to be impaired, the impairment to be recognized is measured as the amount by which the carrying amount of the assets exceeds their fair value. The Company continually evaluates whether events or circumstances have occurred that indicate that the remaining useful life of its long-lived assets may warrant revision or that the carrying value of these assets may be impaired. Factors that the Company considers in deciding when to perform an impairment review include significant underperformance of the business in relation to expectations, significant negative industry or economic trends, and significant changes or planned changes in the use of the assets. Evaluation of recoverability of the asset or asset group is based on an estimate of undiscounted future cash flows resulting from the use of the asset or asset group and its eventual disposition. In the event that such cash flows are not expected to be sufficient to recover the carrying amount of the asset or asset group, the assets are written down to their estimated fair value. The impairment loss would be based on the excess of the carrying value of the impaired asset over its fair value, determined based on discounted cash flows. As of each balance sheet date presented, none of the Company’s long-lived assets were impaired. The Company has no t recorded any impairment losses to date other than to property and equipment. Legal and Other Contingencies The Company accounts for its contingent liabilities in accordance with ASC Topic 450, “Contingencies”. A provision is recorded when it is both probable that a liability has been incurred and the amount of the loss can be reasonably estimated. With respect to legal matters, provisions are reviewed and adjusted to reflect the impact of negotiations, estimated settlements, legal rulings, advice of legal counsel and other information and events pertaining to a particular matter. For the years ended December 31, 2022 and 2021 , the Company was not a party to any litigation that was reasonably possible to have a material adverse effect on the Company’s business, financial position, results of operations or cash flows (see also Note 9, “Legal and Other Contingencies”). Legal costs incurred in connection with loss contingencies are expensed as incurred. Research and Development Expenses Research and development expenses are comprised of costs incurred in performing research and development activities, including salaries, stock-based compensation and benefits for employees performing such activities, certain allocated facilities and support costs, depreciation, third-party license fees, and external costs of vendors engaged to conduct preclinical development activities and clinical trials. Research and development expenses are expensed as incurred and include the Company’s costs of performing services in connection with its collaboration agreements and research grants. Non-refundable prepayments for goods or services that will be used or rendered for future research and development activities are deferred and capitalized in prepaid expenses and other current assets. Such amounts are recognized as an expense as the goods are delivered or the related services are performed, or until it is no longer expected that the goods will be delivered, or the services rendered. The Company enters into arrangements with contract research organizations in connection with clinical trials. Such arrangements often provide for payment prior to commencing the project or based upon predetermined milestones throughout the period during which services are expected to be performed. As part of the process of preparing the Company’s financial statements, management is required to estimate prepaid and accrued clinical trial expenses. The date on which services commence, the level of services performed on or before a given date, and the cost of such services are often determined based on subjective judgments informed by the facts and circumstances know to management from the terms of the contract and the Company’s ongoing monitoring of service performance. The Company makes these judgments based upon the facts and circumstances known to management based on the terms of the contract and the Company’s ongoing monitoring of service performance. Fair Value of Financial Instruments Fair value is determined based on the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal market for the asset or liability in an orderly transaction between market participants. U.S. GAAP specifies a hierarchy of valuation techniques based upon whether the inputs to those valuation techniques reflect assumptions other market participants would use based upon market data obtained from independent sources (observable inputs) or reflect the Company’s own assumptions of market participant valuation (unobservable inputs). The fair value hierarchy consists of three levels: Level 1 - Quoted prices (unadjusted) in active markets that are unadjusted and accessible at the measurement date for identical, unrestricted assets or liabilities. Level 2 - Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3 - Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Financial assets and liabilities are classified within the fair value hierarchy based on the lowest level of input that is significant to the fair value measurement. The authoritative guidance requires the use of observable market data if such data is available without undue cost and effort. When available, the Company uses unadjusted quoted market prices to measure fair value and classify such items within Level 1. If quoted market prices are not available, fair value is based upon internally developed models that use, where possible, current market-based or independently-sourced market parameters, such as interest and currency rates and comparable transactions. Items valued using internally generated models are classified according to the lowest level input or value driver that is significant to the valuation. Thus, items may be classified in Level 3 even though there may be inputs that are readily observable. If quoted market prices are not available, the valuation model used generally depends on the specific asset or liability being valued. The Company did no t have any transfers of financial assets between Level 2 and 3 during 2022 or 2021. Some assets and liabilities are required to be recorded at fair value on a recurring basis, while other assets and liabilities are recorded at fair value on a nonrecurring basis. The carrying amounts of current financial instruments, which include cash and cash equivalents, restricted bank deposits, accounts payable, accrued expenses, lease obligation liability and debt, approximate their fair values due to the short-term nature of these instruments. Stock-Based Compensation The Company accounts for stock-based compensation in accordance with ASC Topic 718, “Compensation-Stock Compensation” (“ASC 718”), which requires companies to estimate the fair value of equity-based payment awards on the date of grant using an option-pricing model. The Company recognizes compensation expenses for the value of its awards granted based on the straight-line method over the requisite service period of each of the awards or over the implicit service period when a performance condition affects the vesting, and it is considered probable that the performance condition will be achieved. The Company determines the fair value of each stock option award at its grant date using the Black-Scholes option pricing model for options awarded in 2022 and 2021. The Company determines the fair value of each restricted stock unit, or RSU, at its grant date based on the closing market price of the Company’s common stock on that date. Warrants The Company accounts for warrants on capital stock based on guidelines provided in ASC Topic 815, Derivatives and Hedging—Contracts in Entity’s Own Equity (“ASC 815”), which provides guidance on contracts that are settled in the Company’s own shares as either a liability or as an equity instrument depending on the warrant agreement. The Company's warrants are all classified as equity instruments. As such, the Company uses the Black-Scholes pricing model, depending on the applicable terms of the warrant agreement, to value the warrants at the issuance date. Income Taxes The Company accounts for income taxes in accordance with ASC Topic 740, “Income Taxes” (“ASC 740”), which prescribes the use of the asset and liability method whereby deferred tax assets and liability account balances are determined based on differences between financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to be recovered or settled. The Company provides a valuation allowance, if necessary, to reduce deferred tax assets to their estimated realizable value if it is more likely than not that a portion or all of the deferred tax assets will not be realized. The Company considers many factors when assessing the likelihood of future realization of deferred tax assets, including recent earnings results, expectations of future taxable income, carryforward periods available and other relevant factors. The Company records changes in the required valuation allowance in the period that the determination is made. Based on ASC 740, a two-step approach is used to recognize and measure uncertain tax positions. The first step is to evaluate the tax position taken or expected to be taken in a tax return by determining if the weight of available evidence indicates that it is more likely than not that, on an evaluation of the technical merits, the tax position will be sustained on audit, including resolution of any related appeals or litigation processes. The second step is to measure the tax benefit as the largest amount that is more than 50% likely to be realized upon ultimate settlement. As of December 31, 2022 and 2021 , no liability for unrecognized tax positions has been recorded. Accordingly, no interest or penalties related to uncertain tax positions are recorded. The Company’s policy is to record any interest or penalties associated with unrecognized tax positions as a component of income tax expense. Net Loss per Share, Basic and Diluted Basic loss per share is computed by dividing the loss for the period applicable to ordinary shareholders by the weighted average number of ordinary shares outstanding during the period. In computing diluted income per share, weighted average shares used in computing basic earnings per share are adjusted to reflect the potential dilution that could occur upon the exercise of outstanding stock options and upon conversion of restricted stock units and warrants issued to investors and service providers using the “treasury stock method”. Leases At the inception of an arrangement, the Company determines whether the arrangement is or contains a lease. Leases with a term greater than one year are recognized on the consolidated balance sheet as a right-of-use (“ROU”) asset and current and non-current lease liabilities, as applicable. The Company has made an accounting policy election, known as the short-term lease recognition exemption, which allows the Company to not recognize ROU assets and lease liabilities that arise from short-term leases (12 months or less); The Company has applied this election to all classes of underlying assets. The Company typically only includes an initial lease term in its assessment of a lease arrangement. Options to renew or options to cancel a lease are not included in the Company’s assessment unless there is reasonable certainty that the Company will renew or will not cancel, respectively. The Company monitors its material leases on a quarterly basis. Operating lease liabilities and their corresponding ROU assets are recorded based on the present value of future lease payments over the expected remaining lease term. Lease cost for operating leases is recognized on a straight-line basis over the lease term as an operating expense. Certain adjustments to the ROU asset may be required for items such as lease prepayments or incentives received. The interest rate implicit in lease contracts is typically not readily determinable. As a result, the Company utilizes its incremental borrowing rate, which reflects the fixed rate at which the Company could borrow on a collateralized basis the amount of the lease payments in the same currency, for a similar term, in a similar economic environment. The Company has elected to account for the lease and non-lease components together for all leases. Recent Accounting Pronouncements In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting, which provides optional expedients and exceptions to applying the guidance on contract modifications, hedge accounting, and other transactions, to simplify the accounting for transitioning from the London Interbank Offered Rate ("LIBOR"), and other interbank offered rates expected to be discontinued, to alternative reference rates. The guidance in this Update was effective upon its issuance. If elected, the guidance is to be applied prospectively through December 31, 2022. The adoption of this ASU did not have a material impact on our consolidated financial statements, including but not limited to our research and development grant agreements with the Israel Innovation Authority, discussed in additional detail Note 9, Commitments and Contingencies. While this agreement continues to use LIBOR as of December 31, 2022, any future change to an alternate interest rate is not expected to be material. Although the FASB has issued several other ASUs for which adoption dates are pending, the Company does not expect any of them to have any impacts on its consolidated financial statements.

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	12 Months Ended
	Dec. 31, 2022
Prepaid And Other Current Assets [Abstract]
Prepaid Expenses and Other Current Assets	3. Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consisted of the following (in thousands): December 31, 2022 2021 Research and development $ 366 $ 413 Insurance 93 123 Other 202 377 Totals $ 661 $ 913

Property and Equipment, net

Property and Equipment, net	12 Months Ended
	Dec. 31, 2022
Property, Plant and Equipment [Abstract]
Property and Equipment, net	4. Property and Equipment, net Property and equipment, net consisted of the following (in thousands): December 31, 2022 2021 Computers and software $ 26 $ 31 Office furniture and equipment 15 27 Laboratory equipment 251 221 Leasehold improvements 57 88 Assets in progress - 20 Total property and equipment, at cost 349 387 Less: Accumulated depreciation and amortization ( 180 ) ( 171 ) Property and equipment, net $ 169 $ 216 Depreciation expense was $ 77 thousand and $ 114 thousand for the years ended December 31, 2022 and 2021 , respectively. During the year ended December 31, 2022, the Company recognized an impairment loss of equipment of $ 36 thousand.

Accrued Expenses

Accrued Expenses	12 Months Ended
	Dec. 31, 2022
Payables and Accruals [Abstract]
Accrued Expenses	5. Accrued Expenses Accrued expenses consisted of the following (in thousands): December 31, 2022 2021 Research and development $ 1,544 $ 1,849 Payroll, bonus and other employee-related expenses 750 1,615 Professional services 225 489 Interest on debt 146 102 Other 134 141 Total $ 2,799 $ 4,196

Leases

Leases	12 Months Ended
	Dec. 31, 2022
Leases [Abstract]
Leases	6. Leases Operating lease costs under the leases for the years ended December 31, 2022 and 2021 were approximately $ 0.7 million and $ 1.1 million, respectively. The weighted average remaining lease term at December 31, 2022 was 1.18 years and the weighted average incremental borrowing rate was 5.4 % . In January 2022 , the Company entered into a new lease agreement for office space in Israel for an initial period of 24 months and with the option to extend the lease for an additional 24 months. The lease commenced on April 1, 2022 at the rate of approximately $ 36 thousand per year, billed monthly, plus the Company’s share of utilities, common area expenses, and taxes. Upon commencement of the lease, the Company recognized a right-of-use asset and related liability of $ 64 thousand. The following table summarizes the Company’s maturities of operating lease liabilities as of December 31, 2022 (in thousands): 2023 $ 740 2024 134 2025 2 Total lease payments 876 Less imputed interest ( 29 ) Total operating lease liabilities 847 Less: current portion ( 712 ) Long-term portion $ 135

Debt

Debt	12 Months Ended
	Dec. 31, 2022
Debt Disclosure [Abstract]
Debt	7. Debt Hercules Term Loan On September 30, 2021, the Company entered into a Loan and Security Agreement, dated as of September 30, 2021 (the “Hercules Loan Agreement”) with Hercules Capital, Inc., (“Hercules” or the “Lender”). The Hercules Term Loan Agreement provided for term loans in an aggregate principal amount of up to $ 30.0 million, comprised of (i) a tranche 1 advance of $ 12.5 million (the “Tranche 1 Advance”), (ii) a tranche 2 advance of $ 7.5 million (the “Tranche 2 Advance”) and (iii) a tranche 3 advance of $ 10.0 million (the “Tranche 3 Advance”) (collectively, the “Term Loan Advances”). The Tranche 1 Advance under the Hercules Term Loan Agreement was funded on September 30, 2021. The Tranche 2 Advance was to be available at the Company’s election until August 15, 2022, subject to the Company's achievement of certain milestone events relating to data from the clinical trials. The Company did not meet the requirements for the Tranche 2 Advance and such funding will, therefore, not be available to the Company. The Tranche 3 Advance is available subject to approval by the Lenders’ investment committee in its sole discretion. The Tranche 3 Advance may be available for funding until, initially, April 1, 2023, and (i) upon the occurrence of certain milestone events relating to the Company’s receipt of net cash proceeds from unrestricted equity investments in the Company, October 1, 2023, and (ii) upon the occurrence of certain milestone events relating to the Company’s receipt of net cash proceeds and certain milestone events relating to data from the clinical trials, April 1, 2024. As security for its obligations, the Company granted Hercules a continuing security interest in substantially all of the assets of the Company, subject to certain customary exceptions, including for intellectual property. Any outstanding principal on the Term Loan Advances will accrue interest at a floating rate equal to the greater of (i) 9.50 % per annum and (ii) the sum of 6.25 % plus the prime rate, as published in The Wall Street Journal . As of December 31, 2022 and 2021, the interest rate was 13.75 % and 9.5 %, respectively. Interest payments are payable monthly following the funding of a Term Loan Advance. The Company will be required to make principal payments on the outstanding balance of the Term Loan Advances commencing on April 1, 2023 (the “Term Loan Amortization Date”) in 36 equal monthly installments, plus interest; provided that if the Company has achieved the milestones described above, then the Term Loan Amortization Date will be automatically extended to October 1, 2023 or April 1, 2024, as applicable. Any amounts outstanding under the Term Loan Advances, if not repaid sooner, are due and payable on April 1, 2025 (the “Maturity Date”). On any date that the Company partially repays the outstanding obligations, the Company shall pay the Lenders a charge equal to 6.55 % of the original principal amount. The Company may prepay the outstanding principal amount of the Term Loan Advances at any time (in whole, but not in part), plus accrued and unpaid interest and a prepayment premium equal to (i) 3 % of the principal amount outstanding if prepaid on or prior to the first anniversary of the date of Loan Agreement, (ii) 2 % of the principal amount outstanding if prepaid after the first anniversary the date of Hercules Loan Agreement but on or prior to the second anniversary of the date of Hercules Loan Agreement, and (iii) 1 % of the principal amount outstanding if prepaid after the second anniversary of the date of Hercules Loan Agreement but on or prior to the Maturity Date. The Hercules Loan Agreement contains customary affirmative and negative covenants which, among other things, requires the Company to maintain at all times a minimum qualified cash balance equaling amounts ranging from $ 6.3 million to $ 10.0 million ($ 10.0 million effective as of August 15, 2022 and December 31, 2022) plus qualified accounts payable (as defined) and limits the Company’s ability to (i) incur additional indebtedness, (ii) pay dividends or make certain distributions, (iii) dispose of its assets, grant liens or encumber its assets or (iv) fundamentally alter the nature of its business. These covenants are subject to a number of exceptions and qualifications. The Company was in compliance with all debt covenants at December 31, 2022. The Hercules Loan Agreement also contains customary events of default, including the Company’s failure to make any principal or interest payments when due, the occurrence of certain bankruptcy or insolvency events or a breach of the covenants. Upon the occurrence of an event of default, Hercules may, among other things, accelerate the Company’s obligations under the Hercules Loan Agreement. As of December 31, 2022, the carrying value of the outstanding loan consists of $ 12.5 million in principal less an unamortized debt discount of $ 0.8 million. The debt issuance costs and the final maturity payment of $ 0.8 million, have been recorded as a debt discount which are being accreted to interest expense through the maturity date of the loan. Interest expense relating to the loan for the years ended December 31, 2022 and 2021 was $ 1.9 million and $ 0.4 million, respectively. Interest expense is calculated using the effective interest method and is inclusive of non-cash amortization of the debt discount. As of December 31, 2022, the effective interest rate was 19.5 %. On March 7, 2023, the Company entered into an amendment to repay $ 7.5 million of the outstanding principal of the Hercules Term Loan, extend the interest only period until September 1, 2023, and reduce the qualified cash balance to $ 2.25 million as of March 7, 2023. The Company will be required to make principal payments on the remaining $ 5.0 million outstanding principal balance of the Term Loan Advances commencing on September 1, 2023, plus interest, with a final maturity date of April 1, 2025. See Note 19, Subsequent Events. The Company’s scheduled future principal payments for the long-term debt are as follows (in thousands): December 31, 2022 2023 $ 4,204 2024 6,101 2025 2,195 Total future principal payments 12,500 Less: unamortized discount ( 782 ) Carrying value of long-term debt 11,718 Less: current portion ( 3,980 ) Add: final Term Loan fee due at maturity in 2023 819 Long-term portion $ 8,557 SVB Term Loan On January 30, 2019, the Company entered into a Loan and Security Agreement (the “Loan Agreement”) in the amount of $ 15.0 million with Silicon Valley Bank (“SVB”) and WestRiver Innovation Lending Fund VIII, L.P. (“WestRiver”, and together with SVB, the “SVB Lenders”). Outstanding principal on the loan accrues interest at a floating rate equal to the greater of (i) 5.25 % per annum and (ii) the sum of 2.5 % plus the prime rate, as published in The Wall Street Journal. Interest payments are payable monthly. On September 30, 2021, the interest rate was 5.75 %. The Company commenced making payments on the outstanding principal balance of the loan on February 1, 2020, which was payable in 36 equal monthly installments and scheduled to fully mature on January 1, 2023 . In conjunction with the initial loan advance, the Company issued warrants to the SVB Lenders to purchase 1,021 shares of common stock at a price of $ 440.80 per share (subject to certain adjustments). The Company may prepay the outstanding principal balance of the loans advanced in whole but not in part, subject to a prepayment fee ranging from 1 % to 3 % of any amount prepaid, depending upon when the prepayment occurs. The Company will also pay a final payment fee equal to 6 % of the total loans advanced, due upon the earlier of maturity or termination of the Loan Agreement. On September 30, 2021, in connection with the funding of the Hercules Term Loan Tranche 1 Advance and pursuant to a Payoff Letter dated September 30, 2021, the Company voluntarily repaid in full the carrying value of the outstanding loan consisting of $ 6.7 million of principal, a final maturity payment of $ 0.9 million, and early termination fees of $ 0.1 million from funds received under the Hercules Loan Agreement. The debt issuance costs, the valuation of the warrants, and the final maturity payment of $ 0.9 million, had been recorded as a debt discount which were being accreted to interest expense through the maturity date of the loan. The remaining unamortized debt discount of $ 0.2 million and early termination fees were accounted for as a loss on debt extinguishment and included in other income and expense in the statement of operations for the year ended December 31, 2021. Interest expense relating to the loan for the years ended December 31, 2022 and 2021 was $ 0 and $ 0.9 million, respectively. Interest expense is calculated using the effective interest method and is inclusive of non-cash amortization of the debt discount. PPP Loan In April 2020, the Company entered into a loan agreement with SVB under the U.S. Small Business Administration (the “SBA”) Paycheck Protection Program (the “PPP”) pursuant to the Coronavirus Aid, Relief and Economic Security Act of 2020 (the “CARES Act”) and received loan proceeds of $ 0.8 million (the “PPP Loan”). The Company used the loan proceeds for payroll and other covered costs in accordance with the relevant terms and conditions of the CARES Act. The PPP Loan had a maturity date of April 21, 2022 and an interest rate of 1.0 % per annum. Under the terms of the PPP, on September 3, 2021, the PPP Loan was forgiven in full, and the Company recognized a gain on extinguishment of debt of $ 0.8 million during the year ended December 31, 2021. The SBA reserves the right to audit any PPP loan, regardless of size. These audits may occur after forgiveness has been granted. In accordance with the CARES Act, all borrowers are required to maintain their PPP loan documentation for six years after the PPP loan was forgiven or repaid in full and to provide that documentation to the SBA upon request.

Related Parties

Related Parties	12 Months Ended
	Dec. 31, 2022
Related Party Transactions [Abstract]
Related Parties	8. Related Parties On August 29, 2013, the Company entered into the Technion Agreement with TRDF, with respect to certain technology relating to aminoglycosides and the redesign of aminoglycosides for the treatment of human genetic diseases caused by premature stop mutations and further results of the research of the technology, in order to develop and commercialize products based on such technology. Under the Technion Agreement, TRDF is obligated to provide the Company with research services for an estimated annual payment of $ 0.1 million, the precise amount to be agreed by the parties prior to the beginning of each year of the research period. During the years ended December 31, 2022 and 2021 no expenses were incurred. As of December 31, 2022 and 2021 no amounts were recorded in accrued expenses. In addition, TRDF granted the Company a license to use, market, sell or sub-license the rights of the product developed under the TRDF research results (the “Licensed Product”), as fully defined in the Technion Agreement, for the following considerations: (i) milestone payments up to total consideration of $ 6.1 million, to be transferred upon meeting certain milestones as defined in the Technion Agreement; (ii) certain royalties in the low- to mid-single-digit percentage of net sales (subject to change in the case of (a) sublicensing to a big pharmaceutical or biotechnology company, or (b) payment of royalties to third parties, or (c) commercialization by a third party of an authorized generic to a licensed product), for a period until the later of (i) the expiration of a valid claim on the Licensed Product in each country the Licensed Product is sold to, or (ii) a certain amount of years from the date of the first commercial sale of the Licensed Product in such country; and (iii) a low- to mid-double-digit percentage of any non-royalty sub-license income received by the Company from a sub-licensed entity. The Company made no milestone or royalty payments to the TRDF during the years ended December 31, 2022 or 2021.

Advances From Collaboration Par

Advances From Collaboration Partners, Legal, and Other Contingencies	12 Months Ended
	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	9. Advances From Collaboration Partners, Legal, and Other Contingencies Cystic Fibrosis Foundation During 2019, the Company received a funding award (the “2019 CFF Award”) from the Cystic Fibrosis Foundation (“CFF”) for up to $ 3.6 million and entered into an agreement relating to the award, which agreement was amended in December 2020 and March 2022. Payment of award amounts are subject to the achievement of certain milestones in connection with the Company’s global cystic fibrosis development program. The Company will be required to repay amounts received from the CFF (or specified multiples of such amounts) in certain circumstances, including as royalties on net sales, and, in the event of a disposition of the underlying asset (as defined in the agreement), in which case the Company would be obliged to use up to 5 % of the amounts received from the disposition to repay up to three times the award amount. The funding provided to the Company is accounted for as an advance from a collaboration partner within the scope of ASC Topic 730, “Research and Development.” As of December 31, 2021, the Company had received payments of $ 3.4 million, which are recorded as Advances from collaboration partners in the accompanying consolidated financial statements. In March 2022, the Company entered into an agreement with the CFF to amend the 2019 CFF Award to provide for up to an additional $ 15.9 million to fund the ongoing global Phase 2 clinical development of ELX-02 in cystic fibrosis (the “2022 CFF Amendment”). The Company received an upfront payment of $ 7.0 million in March 2022 and a milestone payment of $ 1.5 million in September 2022, which were recorded as Advances from collaboration partners in the accompanying consolidated financial statements. In September 2022, the CFF determined not to continue funding this program and the remaining $ 7.4 million of the award under the 2022 CFF Amendment will not be available to the Company under the current development program. Upon successful commercialization of ELX-02 or any derivative products thereof, the Company will pay the CFF royalties up to 6 % of net sales based on the on the actual amount of funding from the CFF and potential sales milestones. In addition, the 2022 CFF Agreement includes an embedded derivative arising from a provision that upon the occurrence of a change of control or sale or license of funded assets (each a disposition event), the Company would be required to pay the CFF 10 % of the consideration received for the disposition event up to three times the amount of funds received from the CFF under the 2022 CFF Agreement. In May 2021, the Company received an additional award from the CFF (the “2021 CFF Award”) for up to $ 2.6 million to help identify optimized oral RMAs for further development in the treatment of cystic fibrosis patients with nonsense mutations. Payment of award amounts are subject to the achievement of certain milestones in connection with the Company’s oral RMA cystic fibrosis development program. The Company will be required to repay amounts received from the CFF (or specified multiples of such amounts) in certain circumstances, including as royalties on net sales (with royalties capped at eight times the award amount received, the "Royalty Cap"), and, in the event of a disposition of the underlying asset. The funding provided to the Company is accounted for as an advance from a collaboration partner within the scope of ASC Topic 730, “Research and Development.” As of December 31, 2022 and 2021, the Company had received payments of $ 0.6 million and $ 0.3 million, respectively, under this award, which are recorded as Advances from collaboration partners in the accompanying consolidated financial statements. The 2021 CFF Award includes an embedded derivative arising from a provision that upon the occurrence of a change of control or sale or license of funded assets (each a disposition event) the Company would be required to pay the CFF 20 % of the consideration received for the disposition event, and 10 % for a sale or license event, up to eight times the amount of funds received from the CFF under the 2021 CFF Agreement. The fair value of the embedded derivatives related to the 2019 CFF Award and the 2021 CFF Award as described above were concluded to be de minimis as of December 31, 2021. In conjunction with the 2022 CFF Agreement, the Company estimated the fair value of the embedded derivatives to be $ 45 thousand as of December 31, 2022 and has recognized this amount on the consolidated balance sheet as derivative liabilities with the corresponding change in value of $ 45 thousand expense recognized as the change in fair value of derivative liabilities in other expense (income), net, in the consolidated statements of operations for the year ended December 31, 2022. Royalty Commitments to the IIA To date, the Company has received research and development grants from the Israel Innovation Authority (the “IIA”) totaling $ 2.6 million. No grants were received for the years ended December 31, 2022 and 2021. Under the research and development agreements with the IIA and pursuant to applicable law, the Company is required to pay royalties at the rate of 3 % on sales to end customers of products candidates developed with funds provided by the IIA, up to an amount equal to 100 % of the IIA research and development grants received, plus interest based on the 12-month LIBOR rate. If the Company does not generate sales of products developed with funds provided by the IIA, the Company is not obligated to pay royalties or repay the grants. As of December 31, 2022, the Company has not commenced the payment obligation of the royalties and has a contingent obligation with respect to royalty-bearing participation received or accrued, amounting to $ 2.8 million, including accrued LIBOR interest. Commitments to TRDF Since August 29, 2013, the Company has had an ongoing agreement with TRDF. Refer to Note 8, “Related Parties”, for further information. License Agreement between Zikani and President and Fellows of Harvard College On February 10, 2015, Zikani entered into an agreement with the President and Fellows of Harvard College (“Harvard”) to license certain patent rights owned by Harvard. This license agreement was subsequently amended and restated on March 31, 2020. Harvard is entitled to receive clinical and regulatory milestone payments totaling up to $ 3.6 million in the aggregate per licensed product approved in the United States, European Union, and Japan. The Company is also obligated to make additional royalty payments to Harvard upon the occurrence of certain sales milestones per licensed product up to a mid-single digit royalty percentage. The royalty percentage depends on the product and whether such licensed product is covered by a valid claim within the certain patent rights that the Company licenses from Harvard. Further, the Company may sub license the patent rights and any income, with the Company obligated to remit to Harvard fees ranging from 20 % to 30 % of such sublicense income up to the achievement of certain milestone events. There were no royalties recorded in 2022 or 2021. Under this agreement, the Company has an exclusive, worldwide, royalty-bearing license under Harvard’s interest in the Patent Rights, and a non-exclusive, worldwide, royalty-bearing license under Harvard’s interest in the Harvard Know-How, solely to develop, make, have made, use, offer for sale, sell, have sold and import and export licensed products solely within the field. Harvard retains the right, for itself and for other not-for-profit research organizations, to practice the patent rights within the scope of the license granted above, solely for non-commercial research, educational and scholarly purposes; provided, that, nothing herein shall be construed as permitting Harvard or any such not-for-profit research organization to grant any rights to any third party, including any for-profit sponsor, to practice or exploit any of the patent rights for any commercial purpose that would be inconsistent with the terms of the exclusive license of the patent rights, including any right to develop, manufacture, market or sell licensed products for use in the field; and the United States federal government retains rights in the patent rights pursuant to 35 U.S.C. §§ 200-212 and 37 C.F.R. § 401 et seq., and any right granted in this agreement greater than that permitted under 35 U.S.C. §§ 200-212 or 37 C.F.R. § 401 et seq. will be deemed modified. In addition to the license agreement, the Company also reimburses Harvard for certain costs related to the maintenance and further development of patents developed through the founding stockholder's research. For the year ended December 31, 2022, the Company incurred $ 0.2 million of patent expenses due to Harvard. For the year ended December 31, 2021, the Company incurred immaterial patent expenses due to Harvard. Contingencies From time to time, the Company may become involved in various lawsuits and legal proceedings, which arise in the ordinary course of business. The Company is currently unaware of any material pending legal proceedings to which it is a party or of which its property is the subject. However, the Company may at times in the future become involved in litigation in the ordinary course of business, which may include actions related to or based on its intellectual property and its use, customer claims, employment practices and employee complaints and other events arising out of its operations. When appropriate in management’s estimation, the Company will record adequate reserves in its financial statements for pending litigation. Litigation is subject to inherent uncertainties, and an adverse result in any such matters could adversely impact its reputation, operations, and its financial operating results or overall financial condition. The Company accounts for contingent liabilities in accordance with ASC Topic 450, “Contingencies”. A provision is recorded when it is both probable that a liability has been incurred and the amount of the loss can be reasonably estimated. With respect to legal matters, provisions are reviewed and adjusted to reflect the impact of negotiations, estimated settlements, legal rulings, advice of legal counsel and other information and events pertaining to a particular matter. As of December 31, 2022 and 2021 , the Company was not a party to any litigation that is reasonably possible to have a material adverse effect on the Company’s business, financial position, results of operations or cash flows. Legal costs incurred in connection with loss contingencies are expensed as incurred.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2022
Equity [Abstract]
Stockholders' Equity	10. Stockholders’ Deficit As of December 31, 2022 , the Company had 500,000,000 shares authorized of common stock, $ 0.01 par value, of which 2,166,356 shares were outstanding and 5,000,000 shares authorized of preferred stock, $ 0.01 par value, of which no shares were issued or outstanding. Common Stock Public Offerings On May 13, 2021, the Company closed an underwritten public offering of 958,333 shares of its common stock at a price of $ 54.00 per share and received gross proceeds of approximately $ 51.8 million, before deducting underwriting discounts and commissions of $ 3.1 million and offering expenses of $ 0.8 million. At the Market Offering Program On September 30, 2021, the Company entered into a Sales Agreement with SVB Leerink, LLC (“SVB Leerink”) pursuant to which the Company may offer and sell up to $ 50.0 million of shares of its common stock (the “ATM Shares”) from time to time, through an “at the market offering” program (the “ATM Program”), under which SVB Leerink will act as sales agent. Pursuant to the Sales Agreement, the Company will set the parameters for the sale of ATM Shares, including the number of ATM Shares to be issued, the time period during which sales are requested to be made, limitations on the number of ATM Shares that may be sold in any one trading day and any minimum price below which sales may not be made. The Company is not obligated to make any sales of Shares under the ATM Program. The Company had not sold any shares under the ATM Program as of December 31, 2022. Warrants Eloxx Limited issued warrants to purchase shares of common stock in conjunction with the Share Purchase Agreements prior to the December 2017 reverse merger between Eloxx Limited and Sevion Therapeutics, Inc. The Company also issued warrants to purchase shares of common stock in connection with the SVB Loan Agreement. During the year ended December 31, 2022, transactions related to warrants were as follows: Shares Weighted Weighted Warrants outstanding at December 31, 2021 8,097 $ 172.40 1.74 Granted - Exercised - Forfeited ( 7,076 ) 133.91 Warrants outstanding at December 31, 2022 1,021 $ 440.80 6.08 Warrants exercisable at December 31, 2022 1,021 $ 440.80 6.08

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	11. Stock-Based Compensation Stock Incentive Plans On March 12, 2018, the Company’s Board of Directors (the “Board”) adopted the 2018 Equity Incentive Plan (the “2018 Plan”). The 2018 Plan became effective on April 20, 2018 upon approval by the stockholders of the Company with the outstanding options and shares available for future grant under any prior plans being assumed by the 2018 Plan. The initial total number of shares available under the 2018 Plan for awards to employees, non-employee directors and other key personnel was 125,000 shares. Stock options granted have a ten-year contractual life and, upon termination of service, vested options are generally exercisable between one and three months following the termination date, while unvested options are forfeited immediately. Summary of Stock Option Activity Transactions during the year ended December 31, 2022 related to stock options granted to employees and directors were as follows: Shares Weighted Weighted Aggregate Options outstanding as of December 31, 2021 222,611 $ 209.60 7.23 $ 254 Granted 86,112 17.88 Exercised - - Forfeited ( 59,320 ) 367.39 Options outstanding as of December 31, 2022 249,403 $ 105.87 8.12 $ 3 Options exercisable at December 31, 2022 81,809 $ 214.06 6.39 $ 3 As of December 31, 2022, the unrecognized compensation cost related to the outstanding options was $ 5.3 million and is expected to be recognized over a weighted-average period of 2.43 years. The weighted average grant date fair values of stock options granted during the years ended December 31, 2022 and 2021 were $ 12.20 and $ 62.40 , respectively. The following table presents the assumptions used to estimate the fair values of stock options granted in the periods presented: Year ended December 31, 2022 2021 Dividend yield 0 % 0 % Volatility 78 %- 82 % 76 %- 77 % Risk-free interest rate 1.84 %- 3.96 % 0.87 %- 1.33 % Expected term (years) 5.5 - 6.0 6.0 Contractual term (years) 10 10 Summary of Restricted Stock Unit Activity Transactions during the year ended December 31, 2022 related to RSUs granted to employees were as follows: Shares Weighted Unvested at December 31, 2021 157 $ 600.80 Vested ( 157 ) 600.80 Unvested at December 31, 2022 - $ - As of December 31, 2022, there was no remaining unrecognized compensation costs related to the RSUs. Stock-based Compensation Expense Stock-based compensation expense relates to stock options granted to employees, non-employee directors and consultants, time-based restricted stock units granted to employees and performance-based stock options and restricted stock units granted to an employee. The total equity-based compensation expense related to all of the Company’s equity-based awards was recognized as follows (in thousands): Year ended December 31, 2022 2021 Research and development $ 1,319 $ 1,336 General and administrative 1,702 7,831 Total stock-based compensation expense $ 3,021 $ 9,167

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Income Taxes	12. Income Taxes The components of income (loss) before taxes on income are as follows (in thousands): Year ended December 31, 2022 2021 U.S. $ ( 22,991 ) $ ( 47,849 ) Israel ( 13,074 ) ( 18,895 ) Australia - 17 Loss before taxes on income $ ( 36,065 ) $ ( 66,727 ) There were no taxes on income during the years ended December 31, 2022 or 2021. The significant components of the Company’s deferred tax assets were comprised of the following (in thousands): December 31, 2022 2021 Deferred tax assets: Net operating loss carryforwards $ 58,334 $ 57,716 Stock-based compensation 1,831 3,143 Reserves and allowances 170 337 U.S. tax credits and other credits 8,226 6,009 Capitalized research and development expenditures 11,184 3,988 Operating lease right-of-use assets ( 197 ) ( 338 ) Operating lease liabilities 203 363 Other 226 371 Total deferred tax assets 79,977 71,589 Valuation allowance ( 79,977 ) ( 71,589 ) Net deferred tax assets $ — $ — Deferred taxes are recognized for temporary differences between the basis of assets and liabilities for financial statements and income tax purposes. The Company has evaluated the positive and negative evidence bearing upon the realizability of its deferred tax assets. As of December 31, 2022 and 2021, based on the Company’s history of operating losses, the Company has concluded that it is more likely than not that the benefit of the deferred tax assets will not be realized. Accordingly, the Company has provided a full valuation allowance for deferred tax assets as of December 31, 2022 and 2021. As of December 31, 2022 and 2021, the Company provided valuation allowances of approximately $ 80.0 million and $ 71.6 million, respectively, on U.S. federal, U.S. state and Israeli tax jurisdiction deferred tax assets to reduce the carrying amounts of these assets to zero . The net changes in the Company’s valuation allowances were increases of $ 8.4 million and $ 19.0 million during the years ended December 31, 2022 and 2021, respectively. For both the years ended December 31, 2022, the increase in the valuation allowance was primarily related to losses generated during the period and increases in research and development credits and other tax credits, partially offset by a reduction in the stock-based compensation deferred tax asset associated with cancelled awards. For the years ended December 31, 2022 and 2021 the expected tax expense based on the federal statutory rate is reconciled with the actual tax expense as follows: Year ended December 31, 2022 2021 U.S. federal statutory rate 21.0 % 21.0 % State tax rate, net of federal benefit 2.2 1.0 Permanent differences ( 7.4 ) ( 7.3 ) Tax credits 6.6 3.5 Effect of rate differences from statutory 1.0 0.6 Change in valuation allowance ( 23.4 ) ( 18.8 ) Income tax provision 0.0 % 0.0 % The main reconciling item between the statutory tax rate and the Company’s effective tax rate is the recognition of valuation allowances in respect to deferred taxes related to accumulated net operating losses carried forward and temporary differences due to the uncertainty of the realization of such deferred taxes. As of December 31, 2022 and 2021, the Company had U.S. federal net operating loss (“NOL”) carryforwards of $ 159.2 million and $ 158.8 million, respectively. U.S. federal NOL carryforwards will begin to expire, if not utilized, beginning in 2023 through 2037 . Included in the U.S. federal NOL carryforward as of December 31, 2022 are $ 84.1 million of NOLs generated after the effective date of the Tax Cuts and Jobs Act of 2017 (the “Tax Act”), which are not subject to expiration but may not be carried back and are only eligible to offset up to a maximum of 80 % of taxable income generated in a given year. It is uncertain if and to what extent various U.S. states will conform their net operating loss rules to the Tax Act. As of December 31, 2022 and 2021, the Company had U.S. state NOL carryforwards of $ 25.9 million and $ 24.2 million, respectively, which may be available to offset future income tax liabilities. As of December 31, 2022 and 2021, the Company had federal research tax credit carryforwards of $ 8.1 million and $ 5.9 million, respectively, available to reduce future tax liabilities and which expire at dates beginning in 2026 through 2041 . As of December 31, 2022 and 2021, the Company had Israeli NOL carryforwards of $ 101.2 million and $ 99.3 million, respectively, which carry forward indefinitely. Under the provisions of the Internal Revenue Code (“IRC”), the net operating loss and tax credit carryforwards are subject to review and potential adjustments by the Internal Revenue Service and state tax authorities. Under Section 382 of the Internal Revenue Code and corresponding provisions of state law, if a corporation undergoes an “ownership change,” which is generally defined as a greater than 50 percent change, by value, in its equity ownership over a three-year period, the corporation’s ability to use its pre-change NOL carryforwards and other pre-change tax attributes to offset its post-change income or taxes may be limited. The Company may have experienced ownership changes in the past, including the reverse merger of Sevion Therapeutics, Inc. on December 19, 2017 at which time the Company’s pre-change U.S. federal NOL carryforward was $ 77.2 million, and its research tax credit was $ 0.7 million. The Company may have experienced ownership change in the Zikani Merger on April 2, 2021. The Company has done a high-level evaluation on the Zikani U.S. federal NOL carryforwards and credits and have written them down accordingly. The Company may experience additional ownership changes in the future as a result of subsequent shifts in its stock ownership, some of which may be outside of its control. Although the Company has not completed its analysis, it is reasonably possible that its federal NOLs available to offset future taxable income could materially decrease. This reduction would be offset by an adjustment to the existing valuation allowance for an equal and offsetting amount. Additionally, the state NOLs available to offset future state income could similarly decrease, which would also be offset by an equal and offsetting adjustment to the existing valuation allowance. Given the offsetting adjustments to the existing valuation allowance, any ownership change is not expected to have an adverse material effect on the Company’s Consolidated Financial Statements. The Company is subject to income taxes in the United States and Israel and Australia. The Company files income tax returns in the U.S. and in several states. The federal and state tax returns are generally subject to tax examination by taxing authorities for tax years December 31, 2019 to present. To the extent the Company has tax attribute carryforwards, the tax years in which the attribute was generated may still be adjusted upon examination by the Internal Revenue Service or state tax authorities to the extent utilized in a future period. The Israeli income tax returns remain open to examination beginning in 2013 to present. The Australia income tax returns remain open to examination beginning in 2021 to present. If and when the Company claims NOL carryforwards from any prior years against future taxable income, those losses may be examined by the taxing authorities.

Net Loss Per Share

Net Loss Per Share	12 Months Ended
	Dec. 31, 2022
Earnings Per Share [Abstract]
Net Loss Per Share	13. Net Loss Per Share The loss and the weighted average number of shares used in computing basic and diluted net loss per share for the years ended December 31, 2022 and 2021, are as follows (in thousands, except share and per share data): Year ended December 31, 2022 2021 Numerator: Net loss $ ( 36,065 ) $ ( 66,727 ) Denominator: Weighted average number of shares of common stock 2,166,311 1,749,071 Net loss per share, basic and diluted $ ( 16.65 ) $ ( 38.15 ) For the years ended December 31, 2022 and 2021, the totals of outstanding preferred stock, stock options, stock warrants and restricted stock units, as applicable, excluded from the calculation of the diluted net loss per share due to their anti-dilutive effect were 250,424 and 230,865 , respectively.

Other Expense (Income), net

Other Expense (Income), net	12 Months Ended
	Dec. 31, 2022
Other Income and Expenses [Abstract]
Other Expense (Income), net	14. Other Expense (Income), net Other Expense (income) consisted of the following (in thousands): Year ended December 31, 2022 2021 Interest and other income $ ( 274 ) $ ( 8 ) Interest and other expense 1,949 1,259 Foreign currency exchange losses (gains), net 3 ( 2 ) Research and development tax credit income ( 77 ) — Change in fair value of derivative liabilities 45 — Gain on debt extinguishment — ( 808 ) Loss on debt extinguishment — 268 Total other expense (income), net $ 1,646 $ 709

Segment and Geographic Informat

Segment and Geographic Information	12 Months Ended
	Dec. 31, 2022
Segment Reporting [Abstract]
Segment and Geographic Information	15. Segment and Geographic Information Operating segments are defined as components of an enterprise (business activity from which it earns revenue and incurs expenses) about which discrete financial information is available and regularly reviewed by the chief operating decision maker in deciding how to allocate resources and in assessing performance. The Company’s chief operating decision maker is its Chief Executive Officer. The chief operating decision maker reviews consolidated operating results to make decisions about allocating resources and assessing performance for the entire company. The Company views its operations and manages its business as one operating segment; however, it operates in three geographic regions: the U.S., Israel, and Australia. Substantially all of the Company’s assets are located in the U.S.

Marketable Securities

Marketable Securities	12 Months Ended
	Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	17. Marketable Securities Below is a summary of cash, cash equivalents and marketable securities at December 31, 2021 (in thousands): Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash and cash equivalents $ 42,268 $ — $ — $ 42,268 Marketable securities - U.S. treasuries — — — — Total cash, cash equivalents and marketable securities $ 42,268 $ — $ — $ 42,268 As of December 31, 2022 and 2021, no credit losses were identified related to the cash equivalents or marketable securities. As of December 31, 2022, the Company did no t have any marketable securities.

Merger Accounting

Merger Accounting	12 Months Ended
	Dec. 31, 2022
Business Combinations [Abstract]
Merger Accounting	16. Merger Accounting On April 1, 2021 , the Company, acquired Zikan i (the "Zikani Merger"), pursuant to an Agreement and Plan of Merger (the “Merger Agreement”). Under the terms of the Merger Agreement, the Company iss ued 189,920 shares of common stock, $ 0.01 par value per share (“Eloxx Common Stock”), in exchange for all of the issued and outstanding equity interests of Zikani (the “Merger Consideration”). In addition, the Company issued 11,054 restricted stock units under the Eloxx Pharmaceuticals, Inc. 2018 Equity Incentive Plan (the “Equity Plan”) to certain employees of Zikani in respect of each individual’s prospective service as an employee, officer, consultant or director of the Company. The Company has been determined to be the acquiring company for accounting purposes and has concluded the merger represents an asset acquisition by the Company of Zikani. To determine the accounting for this transaction under U.S. GAAP, a company must assess whether an integrated set of assets and activities will be accounted for as an acquisition of a business or an asset acquisition. The guidance requires an initial screen test to determine if substantially all of the relative fair value of the gross assets acquired is concentrated in a single asset or group of similar non-financial assets. If that screen is met, the set is not a business. In connection with the Zikani Merger, substantially all of the consideration paid is allocable to the fair value of acquired in-process research and development (“IPR&D”) and, as such, the acquisition is treated as an asset acquisition. Zikani’s assets and liabilities have been initially recognized by allocating the accumulated cost of the acquisition based on their relative fair values, as estimated in good faith by management. The net assets acquired as of the transaction date has been combined with the assets, liabilities, and results of operations of the Company on consummation of the Merger. In accordance with ASC 730, Research and Development, the portion of the Merger Consideration allocated to the acquired IPR&D based on its relative fair value is included as an operating expense as there is no alternative future use. The total consideration for the Merger is as follows (in thousands, except per share data): Number of shares of Eloxx common stock issued to Zikani stockholders (1) 190 Actual closing price per share of Company common stock as reported on the Nasdaq Global Market on April 1, 2021 $ 134.40 Adjusted for a discount for lack of marketability (“DLOM”) (1) 87.5 % $ 117.60 Fair value of common stock consideration 22,335 Transaction costs 1,003 Total purchase price $ 23,338 (1) The shares of common stock issued as merger consideration are unregistered and subject to trading restriction under Rule 144. The Company estimated the DLOM based on consideration of multiple valuation methods. A DLOM is applied to the Company’s quoted common stock price to estimate the value of Eloxx common stock issued on a minority, non-marketable basis. The Eloxx Common Stock issued was offered and sold in transactions exempt from registration under the Securities Act of 1933, as amended (the “Securities Act”), in reliance on Section 4(a)(2) thereof and Regulation D thereunder. The following table summarizes the allocation of the cost of the acquisition to the respective assets acquired and liabilities assumed, based on their relative fair values. Cash and cash equivalents $ 1,954 Restricted cash 191 Prepaid expenses and other current assets 296 Operating lease right-of-use asset 1,810 Property and equipment (2) 192 Intangible assets (3) 467 Total Assets 4,910 Accounts payable 1,219 Accrued expenses 748 Current portion of operating lease liability 588 Operating lease liability 1,222 Total liabilities 3,777 Net assets acquired 1,133 In process research and development acquired (4) 22,205 Purchase price 23,338 (2) Zikani’s property and equipment consists principally of laboratory and computer equipment, furniture and fixtures and leasehold improvements. (3) Employee-related intangible assets relate to Zikani’s assembled workforce acquired in the Zikani Merger. (4) IPR&D represents the allocated consideration based on the estimated fair value of Zikani’s IPR&D. In accordance with ASC 730, Research and Development, the fair value of IPR&D acquired in an asset acquisition with no alternative future use be allocated a portion of the consideration transferred and charged to expense at the acquisition date. In addition, the Company incurred and expensed costs directly related to the Zikani Merger totaling approximately $ 1.0 million during the year ended December 31, 2021, included in general and administrative expenses in the consolidated statement of operations. Since the closing date of the Zikani Merger, the results of Zikani’s operations have been included in the Company’s consolidated financial statements.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurements	18. Fair Value Measurements Assets and liabil ities measured at fair value on a recurring basis as of December 31, 2022 are as follows (in thousands: Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Money market funds included in cash and cash equivalents $ 18,737 $ 18,737 $ — $ — Liabilities Embedded derivatives $ 45 $ — $ — $ 45 The Company is party to certain funding awards with the Cystic Fibrosis Foundation, which contain embedded derivatives (refer to Note 9). As of the balance sheet date, the Company has determined the fair value of these embedded derivatives using a Monte Carlo simulation of the occurrence of a disposition event. The Company has used observable input assumptions such as the amount of funding, the Royalty Cap, as well as unobservable assumptions such as the time to occurrence of 3 years, as well as the probability of occurrence of a disposition event. The table below provides a rollforward of the fair value of the embedded derivatives, a Level 3 fair value estimate (in thousands), for the year ended December 31, 2022: Fair value of embedded derivatives, December 31, 2021 $ — Change in fair value of embedded derivative liabilities 45 Fair value of embedded derivatives, December 31, 2022 $ 45

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2022
Subsequent Events [Abstract]
Subsequent Events	19. Subsequent Events On March 7, 2023, the Company and Hercules entered into the First Amendment to the Loan and Security Agreement (the "Hercules LSA Amendment") to amend the terms of the Hercules Loan Agreement. The amended terms provided for the Company to repay $ 7.5 million of the outstanding principal, which the Company did on March 7, 2023. The Company will be required to make principal payments on the remaining $ 5.0 million outstanding principal balance of the Term Loan Advances commencing on September 1, 2023 instead of the original Term Loan Amortization Date of April 1, 202 3 , plus interest, with a final maturity date of April 1, 2025 . Any amounts outstanding under the Term Loan Advances, if not repaid sooner, are due and payable on April 1, 2025 (the “Maturity Date”). Further, the Company may prepay the outstanding amount of the Term Loan Advances at any time, plus accrued and unpaid interest, and with no prepayment premium. Additionally, the debt covenant that required the Company to maintain at all times a minimum qualified cash balance equaling amounts ranging from $ 6.3 million to $ 10.0 million ($ 10.0 million in effect as of December 31, 2022) plus qualified accounts payable, was decreased to $ 2.25 million effective as of March 7, 2023 and may be further reduced to $ 0 if the Company has raised $ 20.0 million in equity investments prior to May 31, 2023.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation and Reclassifications	Basis of Presentation The Company has prepared its consolidated financial statements in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASUs”) promulgated by the Financial Accounting Standards Board (“FASB”).
Reverse Stock Split	Reverse Stock Split On December 1, 2022, the Company effected a 1-for-40 reverse stock split of its common stock (the “Reverse Stock Split”). As further described below, at a special meeting of stockholders held on November 30, 2022 (the “Special Meeting”), the stockholders of the Company approved a proposal to authorize the Company’s Board of Directors, in its discretion following the Special Meeting to amend the Company’s Amended and Restated Certificate of Incorporation, as amended (the “Certificate of Incorporation”), to effect a reverse stock split of all of the outstanding shares of the Company’s common stock, par value $0.01 per share, at a ratio ranging from any whole number between 1-for-2 and 1-for-40, as determined by the Company’s Board of Directors in its discretion. On November 30, 2022, following the Special Meeting, the Company’s Board of Directors approved the Reverse Stock Split at a ratio of 1-for-40. On December 1, 2022, the Company filed with the Secretary of State of the State of Delaware a certificate of amendment to amend the Company’s Certificate of Incorporation to effect the Reverse Stock Split. The Reverse Stock Split became effective at 5:00 p.m., Eastern Time, on December 1, 2022. As a result of the Reverse Stock Split, every 40 shares of the Company’s common stock issued or outstanding were automatically reclassified into one validly issued, fully-paid and nonassessable new share of common stock, subject to the treatment of fractional shares as described below, without any action on the part of the holders. Proportionate adjustments will be made to the exercise prices and the number of shares underlying the Company’s outstanding equity awards, as applicable, and warrants exercisable for shares of common stock, as well as to the number of shares issuable under the Company’s equity incentive plans and certain existing agreements. The common stock issued pursuant to the Reverse Stock Split remain fully paid and non-assessable. The Reverse Stock Split did not affect the number of authorized shares of common stock or the par value of the common stock. No fractional shares were issued in connection with the Reverse Stock Split. Stockholders of record who would otherwise have been entitled to receive fractional shares as a result of the Reverse Stock Split received a cash payment in lieu thereof at a price equal to the fraction to which the stockholder would otherwise be entitled multiplied by the closing sales price per share of the common stock (as adjusted for the Reverse Stock Split) on The Nasdaq Capital Market on November 30, 2022, the last trading day immediately preceding the effective time of the Reverse Stock Split. All share and per share amounts in the accompanying financial statements, related footnotes, and management’s discussion and analysis have been adjusted retroactively to reflect the reverse stock split as if it had occurred at the beginning of the earliest period presented. Effective December 2, 2022, trading of the Company’s common stock on The Nasdaq Capital Market commenced on a split-adjusted basis, under the existing trading symbol “ELOX.”
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of the Company and its subsidiaries. Intercompany balances and transactions have been eliminated upon consolidation.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates, judgments and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. On an ongoing basis, the Company's management evaluates its estimates, which include, but are not limited to, estimates related to accrued expenses, including clinical trials and other research and development related accruals, derivative liabilities, and stock-based compensation expense. The Company bases its estimates on historical experience and other market specific or other relevant assumptions that it believes to be reasonable under the circumstances. Actual results could materially differ from those estimates.
Foreign Currency	Foreign Currency The functional currency of the Company and its subsidiaries is the U.S. dollar. Accordingly, monetary accounts maintained in other currencies are re-measured into U.S. dollars in accordance with ASC Topic 830, “Foreign Currency Matters”. All foreign currency transaction gains and losses arising from transactions denominated in foreign currencies, whether realized or unrealized, are recorded in the statements of operations as other income or expenses.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents. The Company’s cash and cash equivalents include holdings in checking and overnight sweep accounts. The Company’s cash equivalents, which are money market funds held in a sweep account, are measured at fair value on a recurring basis. As of December 31, 2022 and 2021 the balances of cash and cash equivalents were $ 19.2 million and $ 42.3 million, respectively, which approximate fair value and were determined based upon Level 1 inputs. The sweep account is valued using quoted market prices with no valuation adjustments applied. Accordingly, these financial instruments are categorized as Level 1.
Restricted Cash	Restricted Cash At December 31, 2022, and 2021 , restricted cash consisted of bank guarantees related to corporate facilities leases and credit card programs.
Warrants	Warrants The Company accounts for warrants on capital stock based on guidelines provided in ASC Topic 815, Derivatives and Hedging—Contracts in Entity’s Own Equity (“ASC 815”), which provides guidance on contracts that are settled in the Company’s own shares as either a liability or as an equity instrument depending on the warrant agreement. The Company's warrants are all classified as equity instruments. As such, the Company uses the Black-Scholes pricing model, depending on the applicable terms of the warrant agreement, to value the warrants at the issuance date.
Concentrations of Credit Risk and Off-Balance Sheet Risk	Concentrations of Credit Risk and Off-Balance Sheet Risk Financial instruments that potentially subject the Company to credit risk consist primarily of cash and cash equivalents. The Company mitigates its risk with respect to cash and cash equivalents by maintaining its deposits and investments at high-quality financial institutions. The Company invests any excess cash in money market funds and the management of these investments is not discretionary on the part of the financial institution. Substantially all of the Company's cash and cash equivalents are held at Silicon Valley Bank (SVB), and the amounts frequently exceed federally insured limits. On March 10, 2023, the Federal Deposit Insurance Corporation (FDIC) announced that SVB had been closed by the California Department of Financial Protection and Innovation. The United States Department of the Treasury announced in a joint statement with the Federal Reserve and FDIC that depositors of SVB would have access to all of their money starting March 13, 2023, including funds exceeding federally insured limits. The Company is exposed to credit risk in the event of default by the financial institutions holding its cash and cash equivalents. If the Company is unable to access its cash and cash equivalents as needed, its financial position and ability to operate its business will be adversely affected. The Company has no off-balance-sheet concentration of credit risk such as foreign exchange contracts, option contracts or other foreign hedging arrangements.
Property and Equipment	Property and Equipment Property and equipment are recorded at cost, less accumulated depreciation and amortization. Leasehold improvements are amortized over the lesser of the estimated useful life or the expected term of the related lease. Costs associated with maintenance and repairs are expensed as incurred. Depreciation expense is computed on a straight-line method over the estimated useful lives of the respective assets, as follows: Estimated Useful Life Computers and software 3 years Office furniture and equipment 5 to 12 years Laboratory equipment 5 years Leasehold improvement Over the shorter of the expected remaining lease term or estimated useful life Upon sale or disposition of property and equipment, the cost and related accumulated depreciation and amortization are eliminated from the accounts and any resultant gain or loss is credited or charged to operations.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets Property and equipment subject to depreciation are reviewed for impairment in accordance with ASC Topic 360, “Accounting for the Impairment or Disposal of Long-Lived Assets,” whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If such assets are considered to be impaired, the impairment to be recognized is measured as the amount by which the carrying amount of the assets exceeds their fair value. The Company continually evaluates whether events or circumstances have occurred that indicate that the remaining useful life of its long-lived assets may warrant revision or that the carrying value of these assets may be impaired. Factors that the Company considers in deciding when to perform an impairment review include significant underperformance of the business in relation to expectations, significant negative industry or economic trends, and significant changes or planned changes in the use of the assets. Evaluation of recoverability of the asset or asset group is based on an estimate of undiscounted future cash flows resulting from the use of the asset or asset group and its eventual disposition. In the event that such cash flows are not expected to be sufficient to recover the carrying amount of the asset or asset group, the assets are written down to their estimated fair value. The impairment loss would be based on the excess of the carrying value of the impaired asset over its fair value, determined based on discounted cash flows. As of each balance sheet date presented, none of the Company’s long-lived assets were impaired. The Company has no t recorded any impairment losses to date other than to property and equipment.
Legal and Other Contingencies	Legal and Other Contingencies The Company accounts for its contingent liabilities in accordance with ASC Topic 450, “Contingencies”. A provision is recorded when it is both probable that a liability has been incurred and the amount of the loss can be reasonably estimated. With respect to legal matters, provisions are reviewed and adjusted to reflect the impact of negotiations, estimated settlements, legal rulings, advice of legal counsel and other information and events pertaining to a particular matter. For the years ended December 31, 2022 and 2021 , the Company was not a party to any litigation that was reasonably possible to have a material adverse effect on the Company’s business, financial position, results of operations or cash flows (see also Note 9, “Legal and Other Contingencies”). Legal costs incurred in connection with loss contingencies are expensed as incurred.
Research and Development Expenses	Research and Development Expenses Research and development expenses are comprised of costs incurred in performing research and development activities, including salaries, stock-based compensation and benefits for employees performing such activities, certain allocated facilities and support costs, depreciation, third-party license fees, and external costs of vendors engaged to conduct preclinical development activities and clinical trials. Research and development expenses are expensed as incurred and include the Company’s costs of performing services in connection with its collaboration agreements and research grants. Non-refundable prepayments for goods or services that will be used or rendered for future research and development activities are deferred and capitalized in prepaid expenses and other current assets. Such amounts are recognized as an expense as the goods are delivered or the related services are performed, or until it is no longer expected that the goods will be delivered, or the services rendered. The Company enters into arrangements with contract research organizations in connection with clinical trials. Such arrangements often provide for payment prior to commencing the project or based upon predetermined milestones throughout the period during which services are expected to be performed. As part of the process of preparing the Company’s financial statements, management is required to estimate prepaid and accrued clinical trial expenses. The date on which services commence, the level of services performed on or before a given date, and the cost of such services are often determined based on subjective judgments informed by the facts and circumstances know to management from the terms of the contract and the Company’s ongoing monitoring of service performance. The Company makes these judgments based upon the facts and circumstances known to management based on the terms of the contract and the Company’s ongoing monitoring of service performance.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Fair value is determined based on the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal market for the asset or liability in an orderly transaction between market participants. U.S. GAAP specifies a hierarchy of valuation techniques based upon whether the inputs to those valuation techniques reflect assumptions other market participants would use based upon market data obtained from independent sources (observable inputs) or reflect the Company’s own assumptions of market participant valuation (unobservable inputs). The fair value hierarchy consists of three levels: Level 1 - Quoted prices (unadjusted) in active markets that are unadjusted and accessible at the measurement date for identical, unrestricted assets or liabilities. Level 2 - Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3 - Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Financial assets and liabilities are classified within the fair value hierarchy based on the lowest level of input that is significant to the fair value measurement. The authoritative guidance requires the use of observable market data if such data is available without undue cost and effort. When available, the Company uses unadjusted quoted market prices to measure fair value and classify such items within Level 1. If quoted market prices are not available, fair value is based upon internally developed models that use, where possible, current market-based or independently-sourced market parameters, such as interest and currency rates and comparable transactions. Items valued using internally generated models are classified according to the lowest level input or value driver that is significant to the valuation. Thus, items may be classified in Level 3 even though there may be inputs that are readily observable. If quoted market prices are not available, the valuation model used generally depends on the specific asset or liability being valued. The Company did no t have any transfers of financial assets between Level 2 and 3 during 2022 or 2021. Some assets and liabilities are required to be recorded at fair value on a recurring basis, while other assets and liabilities are recorded at fair value on a nonrecurring basis. The carrying amounts of current financial instruments, which include cash and cash equivalents, restricted bank deposits, accounts payable, accrued expenses, lease obligation liability and debt, approximate their fair values due to the short-term nature of these instruments.
Stock-Based Compensation	Stock-Based Compensation The Company accounts for stock-based compensation in accordance with ASC Topic 718, “Compensation-Stock Compensation” (“ASC 718”), which requires companies to estimate the fair value of equity-based payment awards on the date of grant using an option-pricing model. The Company recognizes compensation expenses for the value of its awards granted based on the straight-line method over the requisite service period of each of the awards or over the implicit service period when a performance condition affects the vesting, and it is considered probable that the performance condition will be achieved. The Company determines the fair value of each stock option award at its grant date using the Black-Scholes option pricing model for options awarded in 2022 and 2021. The Company determines the fair value of each restricted stock unit, or RSU, at its grant date based on the closing market price of the Company’s common stock on that date.
Income Taxes	Income Taxes The Company accounts for income taxes in accordance with ASC Topic 740, “Income Taxes” (“ASC 740”), which prescribes the use of the asset and liability method whereby deferred tax assets and liability account balances are determined based on differences between financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to be recovered or settled. The Company provides a valuation allowance, if necessary, to reduce deferred tax assets to their estimated realizable value if it is more likely than not that a portion or all of the deferred tax assets will not be realized. The Company considers many factors when assessing the likelihood of future realization of deferred tax assets, including recent earnings results, expectations of future taxable income, carryforward periods available and other relevant factors. The Company records changes in the required valuation allowance in the period that the determination is made. Based on ASC 740, a two-step approach is used to recognize and measure uncertain tax positions. The first step is to evaluate the tax position taken or expected to be taken in a tax return by determining if the weight of available evidence indicates that it is more likely than not that, on an evaluation of the technical merits, the tax position will be sustained on audit, including resolution of any related appeals or litigation processes. The second step is to measure the tax benefit as the largest amount that is more than 50% likely to be realized upon ultimate settlement. As of December 31, 2022 and 2021 , no liability for unrecognized tax positions has been recorded. Accordingly, no interest or penalties related to uncertain tax positions are recorded. The Company’s policy is to record any interest or penalties associated with unrecognized tax positions as a component of income tax expense.
Net Loss per Share	Net Loss per Share, Basic and Diluted Basic loss per share is computed by dividing the loss for the period applicable to ordinary shareholders by the weighted average number of ordinary shares outstanding during the period. In computing diluted income per share, weighted average shares used in computing basic earnings per share are adjusted to reflect the potential dilution that could occur upon the exercise of outstanding stock options and upon conversion of restricted stock units and warrants issued to investors and service providers using the “treasury stock method”.
Leases	Leases At the inception of an arrangement, the Company determines whether the arrangement is or contains a lease. Leases with a term greater than one year are recognized on the consolidated balance sheet as a right-of-use (“ROU”) asset and current and non-current lease liabilities, as applicable. The Company has made an accounting policy election, known as the short-term lease recognition exemption, which allows the Company to not recognize ROU assets and lease liabilities that arise from short-term leases (12 months or less); The Company has applied this election to all classes of underlying assets. The Company typically only includes an initial lease term in its assessment of a lease arrangement. Options to renew or options to cancel a lease are not included in the Company’s assessment unless there is reasonable certainty that the Company will renew or will not cancel, respectively. The Company monitors its material leases on a quarterly basis. Operating lease liabilities and their corresponding ROU assets are recorded based on the present value of future lease payments over the expected remaining lease term. Lease cost for operating leases is recognized on a straight-line basis over the lease term as an operating expense. Certain adjustments to the ROU asset may be required for items such as lease prepayments or incentives received. The interest rate implicit in lease contracts is typically not readily determinable. As a result, the Company utilizes its incremental borrowing rate, which reflects the fixed rate at which the Company could borrow on a collateralized basis the amount of the lease payments in the same currency, for a similar term, in a similar economic environment. The Company has elected to account for the lease and non-lease components together for all leases.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting, which provides optional expedients and exceptions to applying the guidance on contract modifications, hedge accounting, and other transactions, to simplify the accounting for transitioning from the London Interbank Offered Rate ("LIBOR"), and other interbank offered rates expected to be discontinued, to alternative reference rates. The guidance in this Update was effective upon its issuance. If elected, the guidance is to be applied prospectively through December 31, 2022. The adoption of this ASU did not have a material impact on our consolidated financial statements, including but not limited to our research and development grant agreements with the Israel Innovation Authority, discussed in additional detail Note 9, Commitments and Contingencies. While this agreement continues to use LIBOR as of December 31, 2022, any future change to an alternate interest rate is not expected to be material. Although the FASB has issued several other ASUs for which adoption dates are pending, the Company does not expect any of them to have any impacts on its consolidated financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Summary of Useful Lives of Principal Classes of Assets	Depreciation expense is computed on a straight-line method over the estimated useful lives of the respective assets, as follows: Estimated Useful Life Computers and software 3 years Office furniture and equipment 5 to 12 years Laboratory equipment 5 years Leasehold improvement Over the shorter of the expected remaining lease term or estimated useful life

Prepaid Expenses and Other Cu_2

Prepaid Expenses and Other Current Assets (Tables)	12 Months Ended
	Dec. 31, 2022
Prepaid And Other Current Assets [Abstract]
Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consisted of the following (in thousands): December 31, 2022 2021 Research and development $ 366 $ 413 Insurance 93 123 Other 202 377 Totals $ 661 $ 913

Property and Equipment, net (Ta

Property and Equipment, net (Tables)	12 Months Ended
	Dec. 31, 2022
Property, Plant and Equipment [Abstract]
Property and equipment, net	Property and equipment, net consisted of the following (in thousands): December 31, 2022 2021 Computers and software $ 26 $ 31 Office furniture and equipment 15 27 Laboratory equipment 251 221 Leasehold improvements 57 88 Assets in progress - 20 Total property and equipment, at cost 349 387 Less: Accumulated depreciation and amortization ( 180 ) ( 171 ) Property and equipment, net $ 169 $ 216

Accrued Expenses (Tables)

Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2022
Payables and Accruals [Abstract]
Accrued expenses	Accrued expenses consisted of the following (in thousands): December 31, 2022 2021 Research and development $ 1,544 $ 1,849 Payroll, bonus and other employee-related expenses 750 1,615 Professional services 225 489 Interest on debt 146 102 Other 134 141 Total $ 2,799 $ 4,196

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2022
Leases [Abstract]
Summary of Maturities of Operating Lease Liabilities	The following table summarizes the Company’s maturities of operating lease liabilities as of December 31, 2022 (in thousands): 2023 $ 740 2024 134 2025 2 Total lease payments 876 Less imputed interest ( 29 ) Total operating lease liabilities 847 Less: current portion ( 712 ) Long-term portion $ 135

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2022
Debt Disclosure [Abstract]
Schedule of Future Principal Payments for Long-Term Debt	The Company’s scheduled future principal payments for the long-term debt are as follows (in thousands): December 31, 2022 2023 $ 4,204 2024 6,101 2025 2,195 Total future principal payments 12,500 Less: unamortized discount ( 782 ) Carrying value of long-term debt 11,718 Less: current portion ( 3,980 ) Add: final Term Loan fee due at maturity in 2023 819 Long-term portion $ 8,557

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2022
Equity [Abstract]
Summary of Warrants Outstanding	Eloxx Limited issued warrants to purchase shares of common stock in conjunction with the Share Purchase Agreements prior to the December 2017 reverse merger between Eloxx Limited and Sevion Therapeutics, Inc. The Company also issued warrants to purchase shares of common stock in connection with the SVB Loan Agreement. During the year ended December 31, 2022, transactions related to warrants were as follows: Shares Weighted Weighted Warrants outstanding at December 31, 2021 8,097 $ 172.40 1.74 Granted - Exercised - Forfeited ( 7,076 ) 133.91 Warrants outstanding at December 31, 2022 1,021 $ 440.80 6.08 Warrants exercisable at December 31, 2022 1,021 $ 440.80 6.08

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
Transactions Related to Grant of Stock Options to Employees and Directors	Transactions during the year ended December 31, 2022 related to stock options granted to employees and directors were as follows: Shares Weighted Weighted Aggregate Options outstanding as of December 31, 2021 222,611 $ 209.60 7.23 $ 254 Granted 86,112 17.88 Exercised - - Forfeited ( 59,320 ) 367.39 Options outstanding as of December 31, 2022 249,403 $ 105.87 8.12 $ 3 Options exercisable at December 31, 2022 81,809 $ 214.06 6.39 $ 3
Assumptions Used to Estimate Fair Values of Stock Options Granted	The following table presents the assumptions used to estimate the fair values of stock options granted in the periods presented: Year ended December 31, 2022 2021 Dividend yield 0 % 0 % Volatility 78 %- 82 % 76 %- 77 % Risk-free interest rate 1.84 %- 3.96 % 0.87 %- 1.33 % Expected term (years) 5.5 - 6.0 6.0 Contractual term (years) 10 10
Transactions Related to Grant of Restricted Stock Units to Employees	Transactions during the year ended December 31, 2022 related to RSUs granted to employees were as follows: Shares Weighted Unvested at December 31, 2021 157 $ 600.80 Vested ( 157 ) 600.80 Unvested at December 31, 2022 - $ -
Summary of Allocated Stock-based Compensation Expense	The total equity-based compensation expense related to all of the Company’s equity-based awards was recognized as follows (in thousands): Year ended December 31, 2022 2021 Research and development $ 1,319 $ 1,336 General and administrative 1,702 7,831 Total stock-based compensation expense $ 3,021 $ 9,167

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Components of Income (Loss) Before Taxes	The components of income (loss) before taxes on income are as follows (in thousands): Year ended December 31, 2022 2021 U.S. $ ( 22,991 ) $ ( 47,849 ) Israel ( 13,074 ) ( 18,895 ) Australia - 17 Loss before taxes on income $ ( 36,065 ) $ ( 66,727 )
Significant Components of Deferred Tax Assets	The significant components of the Company’s deferred tax assets were comprised of the following (in thousands): December 31, 2022 2021 Deferred tax assets: Net operating loss carryforwards $ 58,334 $ 57,716 Stock-based compensation 1,831 3,143 Reserves and allowances 170 337 U.S. tax credits and other credits 8,226 6,009 Capitalized research and development expenditures 11,184 3,988 Operating lease right-of-use assets ( 197 ) ( 338 ) Operating lease liabilities 203 363 Other 226 371 Total deferred tax assets 79,977 71,589 Valuation allowance ( 79,977 ) ( 71,589 ) Net deferred tax assets $ — $ —
Reconciliation of Expected Tax Expense with Actual Tax Expense	For the years ended December 31, 2022 and 2021 the expected tax expense based on the federal statutory rate is reconciled with the actual tax expense as follows: Year ended December 31, 2022 2021 U.S. federal statutory rate 21.0 % 21.0 % State tax rate, net of federal benefit 2.2 1.0 Permanent differences ( 7.4 ) ( 7.3 ) Tax credits 6.6 3.5 Effect of rate differences from statutory 1.0 0.6 Change in valuation allowance ( 23.4 ) ( 18.8 ) Income tax provision 0.0 % 0.0 %

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2022
Earnings Per Share [Abstract]
Schedule of Loss and Weighted Average Number of Shares Used in Computing Basic and Diluted Net Loss Per Share	The loss and the weighted average number of shares used in computing basic and diluted net loss per share for the years ended December 31, 2022 and 2021, are as follows (in thousands, except share and per share data): Year ended December 31, 2022 2021 Numerator: Net loss $ ( 36,065 ) $ ( 66,727 ) Denominator: Weighted average number of shares of common stock 2,166,311 1,749,071 Net loss per share, basic and diluted $ ( 16.65 ) $ ( 38.15 )

Other Expense (Income), net (Ta

Other Expense (Income), net (Tables)	12 Months Ended
	Dec. 31, 2022
Other Income and Expenses [Abstract]
Schedule of Other Expense (Income)	Other Expense (income) consisted of the following (in thousands): Year ended December 31, 2022 2021 Interest and other income $ ( 274 ) $ ( 8 ) Interest and other expense 1,949 1,259 Foreign currency exchange losses (gains), net 3 ( 2 ) Research and development tax credit income ( 77 ) — Change in fair value of derivative liabilities 45 — Gain on debt extinguishment — ( 808 ) Loss on debt extinguishment — 268 Total other expense (income), net $ 1,646 $ 709

Marketable Securities (Tables)

Marketable Securities (Tables)	12 Months Ended
	Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Summary of Cash, Cash Equivalents and Marketable Securities	Below is a summary of cash, cash equivalents and marketable securities at December 31, 2021 (in thousands): Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash and cash equivalents $ 42,268 $ — $ — $ 42,268 Marketable securities - U.S. treasuries — — — — Total cash, cash equivalents and marketable securities $ 42,268 $ — $ — $ 42,268

Merger Accounting (Tables)

Merger Accounting (Tables)	12 Months Ended
	Dec. 31, 2022
Business Combinations [Abstract]
Summary of Total Consideration for Merger	The total consideration for the Merger is as follows (in thousands, except per share data): Number of shares of Eloxx common stock issued to Zikani stockholders (1) 190 Actual closing price per share of Company common stock as reported on the Nasdaq Global Market on April 1, 2021 $ 134.40 Adjusted for a discount for lack of marketability (“DLOM”) (1) 87.5 % $ 117.60 Fair value of common stock consideration 22,335 Transaction costs 1,003 Total purchase price $ 23,338 (1) The shares of common stock issued as merger consideration are unregistered and subject to trading restriction under Rule 144. The Company estimated the DLOM based on consideration of multiple valuation methods. A DLOM is applied to the Company’s quoted common stock price to estimate the value of Eloxx common stock issued on a minority, non-marketable basis. The Eloxx Common Stock issued was offered and sold in transactions exempt from registration under the Securities Act of 1933, as amended (the “Securities Act”), in reliance on Section 4(a)(2) thereof and Regulation D thereunder.
Summary of Purchase Price Allocation	The following table summarizes the allocation of the cost of the acquisition to the respective assets acquired and liabilities assumed, based on their relative fair values. Cash and cash equivalents $ 1,954 Restricted cash 191 Prepaid expenses and other current assets 296 Operating lease right-of-use asset 1,810 Property and equipment (2) 192 Intangible assets (3) 467 Total Assets 4,910 Accounts payable 1,219 Accrued expenses 748 Current portion of operating lease liability 588 Operating lease liability 1,222 Total liabilities 3,777 Net assets acquired 1,133 In process research and development acquired (4) 22,205 Purchase price 23,338 (2) Zikani’s property and equipment consists principally of laboratory and computer equipment, furniture and fixtures and leasehold improvements. (3) Employee-related intangible assets relate to Zikani’s assembled workforce acquired in the Zikani Merger. IPR&D represents the allocated consideration based on the estimated fair value of Zikani’s IPR&D. In accordance with ASC 730, Research and Development, the fair value of IPR&D acquired in an asset acquisition with no alternative future use be allocated a portion of the consideration transferred and charged to expense at the acquisition date.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Schedule of Assets and liabilities measured at fair value on a recurring basis	Assets and liabil ities measured at fair value on a recurring basis as of December 31, 2022 are as follows (in thousands: Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Money market funds included in cash and cash equivalents $ 18,737 $ 18,737 $ — $ — Liabilities Embedded derivatives $ 45 $ — $ — $ 45
Summary of Rollforward of Fair Value of Embedded Derivatives	The table below provides a rollforward of the fair value of the embedded derivatives, a Level 3 fair value estimate (in thousands), for the year ended December 31, 2022: Fair value of embedded derivatives, December 31, 2021 $ — Change in fair value of embedded derivative liabilities 45 Fair value of embedded derivatives, December 31, 2022 $ 45

Nature of the Business - Additi

Nature of the Business - Additional Information (Detail) - USD ($) $ in Thousands			12 Months Ended
	May 31, 2023	Dec. 01, 2022	Mar. 07, 2023	Dec. 31, 2022	Aug. 15, 2022	Dec. 31, 2021	Sep. 30, 2021
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Accumulated deficit				$ 274,388		$ 238,323
Aggregate principal amount of initial loan advance				11,718
Minimum qualified cash balance				10,000
Cash, cash equivalents and marketable securities						$ 42,268
Description of Common Stock Split		On December 1, 2022, the Company effected a 1-for-40 reverse split of its common stock (the "Reverse Stock Split").
Subsequent Event [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Minimum qualified cash balance	$ 0		$ 2,250
Hercules Term Loan Agreement Member
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Cash, cash equivalents and marketable securities				19,200
Effective cash balance				10,000	$ 10,000
Additional cash and cash equivalent and available for sale debt securities				10,000
Hercules Term Loan Agreement Member | Subsequent Event [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Minimum qualified cash balance			2,250
Repayment of Principal			$ 7,500
Hercules Term Loan Agreement Member | Tranche 1 Advance [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Aggregate principal amount of initial loan advance				12,500			$ 12,500
Second Tranche [Member] | Hercules Term Loan Agreement Member
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Expired, Amount					$ 7,500
Forecast [Member] | Hercules Term Loan Agreement Member
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Minimum qualified cash balance	0
Raised from equity investment	20,000
Minimum [Member] | Subsequent Event [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Minimum qualified cash balance	6,300
Minimum [Member] | Hercules Term Loan Agreement Member
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Minimum qualified cash balance				6,300
Maximum [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Minimum qualified cash balance				10,000
Maximum [Member] | Subsequent Event [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Minimum qualified cash balance	$ 10,000
Maximum [Member] | Hercules Term Loan Agreement Member
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Aggregate principal amount of initial loan advance				30,000			$ 30,000
Minimum qualified cash balance				$ 10,000

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Accounting Policies [Line Items]
Accrued expenses	$ 2,799,000	$ 4,196,000
Other	134,000	141,000
Cash and cash equivalents	$ 19,207,000	42,268,000
Description of reverse stock split	On December 1, 2022, the Company effected a 1-for-40 reverse stock split of its common stock (the “Reverse Stock Split”). As further described below, at a special meeting of stockholders held on November 30, 2022 (the “Special Meeting”), the stockholders of the Company approved a proposal to authorize the Company’s Board of Directors, in its discretion following the Special Meeting to amend the Company’s Amended and Restated Certificate of Incorporation, as amended (the “Certificate of Incorporation”), to effect a reverse stock split of all of the outstanding shares of the Company’s common stock, par value $0.01 per share, at a ratio ranging from any whole number between 1-for-2 and 1-for-40, as determined by the Company’s Board of Directors in its discretion. On November 30, 2022, following the Special Meeting, the Company’s Board of Directors approved the Reverse Stock Split at a ratio of 1-for-40. On December 1, 2022, the Company filed with the Secretary of State of the State of Delaware a certificate of amendment to amend the Company’s Certificate of Incorporation to effect the Reverse Stock Split. The Reverse Stock Split became effective at 5:00 p.m., Eastern Time, on December 1, 2022.
Impairment of long-lived assets	$ 0
Asset Impairment	0
Assets, transfer from level 2 to level 3	0	0
Liability for unrecognized tax benefits	0	0
Interest or penalties related to uncertain tax positions	$ 0	$ 0

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Summary of Useful Lives of Principal Classes of Assets (Detail)	12 Months Ended
	Dec. 31, 2022
Computers and software [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life of asset	3 years
Office furniture and equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life of asset	5 years
Office furniture and equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life of asset	12 years
Laboratory Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life of asset	5 years
Leasehold improvement [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life of asset, description	Over the shorter of the expected remaining lease term or estimated useful life

Prepaid Expenses and Other Cu_3

Prepaid Expenses and Other Current Assets - Schedule of Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Research and development	$ 366	$ 413
Insurance	93	123
Other	202	377
Totals	$ 661	$ 913

Property and Equipment, net - P

Property and Equipment, net - Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Total property and equipment, at cost	$ 349	$ 387
Less: Accumulated depreciation and amortization	(180)	(171)
Property and equipment, net	169	216
Computers and software [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, at cost	26	31
Office furniture and equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, at cost	15	27
Laboratory equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, at cost	251	221
Leasehold improvement [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, at cost	57	88
Assets in progress [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, at cost	$ 0	$ 20

Property and Equipment, net - A

Property and Equipment, net - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Abstract]
Depreciation expenses	$ 77	$ 114
Impairment loss of equipment	$ 36

Accrued Expenses - Accrued Expe

Accrued Expenses - Accrued Expenses (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Payables and Accruals [Abstract]
Research and development	$ 1,544	$ 1,849
Payroll, bonus and other employee-related expenses	750	1,615
Professional services	225	489
Interest on debt	146	102
Other	134	141
Total	$ 2,799	$ 4,196

Leases - Additional Information

Leases - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jan. 31, 2022	Dec. 31, 2022	Dec. 31, 2021
Leases [Line Items]
Operating lease cost		$ 700	$ 1,100
Operating lease weighted average incremental borrowing rate		5.40%
Weighted average remaining lease term		1 year 2 months 4 days
Right-of-use asset and related liability recognized		$ 825	$ 1,443
Israel [Member]
Leases [Line Items]
Lease agreement date	Jan. 31, 2022
Lease agreement initial period	24 months
Option to extend term for duration period	24 months
Lease commencement date	Apr. 01, 2022
Lessee operating lease commencing amount	$ 36
Right-of-use asset and related liability recognized	$ 64

Leases - Summary of Maturities

Leases - Summary of Maturities of Operating Lease Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Leases [Abstract]
2023	$ 740
2024	134
2025	2
Total lease payments	876
Less imputed interest	(29)
Total operating lease liabilities	847
Less: current portion	(712)	$ (657)
Operating lease liability	$ 135	$ 804

Debt - Additional Information (

Debt - Additional Information (Detail) $ / shares in Units, $ in Thousands				1 Months Ended	9 Months Ended	12 Months Ended
	Sep. 01, 2023 USD ($)	Mar. 07, 2023 USD ($)	Jan. 30, 2019 USD ($) Installment $ / shares shares	Apr. 30, 2020 USD ($)	Sep. 30, 2021 USD ($)	Dec. 31, 2022 USD ($) $ / shares	Dec. 31, 2021 USD ($) $ / shares	May 31, 2023 USD ($)	Aug. 15, 2022 USD ($)
Debt Instrument [Line Items]
Aggregate principal amount of initial loan advance						$ 11,718
Debt instrument, interest rate terms			Outstanding principal on the loan accrues interest at a floating rate equal to the greater of (i) 5.25% per annum and (ii) the sum of 2.5% plus the prime rate, as published in The Wall Street Journal. Interest payments are payable monthly.
Minimum qualified cash balance						10,000
Loan, principal outstanding						12,500
Loan, unamortized debt discount						782
Loan, final maturity payment						$ (819)
Warrant exercise price per share | $ / shares						$ 440.80	$ 172.40
Subsequent Event [Member]
Debt Instrument [Line Items]
Loan, maturity date		Apr. 01, 2025
Minimum qualified cash balance		$ 2,250						$ 0
Short-Term Debt, Average Outstanding Amount	$ 5,000	7,500
Minimum [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Minimum qualified cash balance								6,300
Maximum [Member]
Debt Instrument [Line Items]
Minimum qualified cash balance						$ 10,000
Maximum [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Minimum qualified cash balance								$ 10,000
Hercules Term Loan Agreement Member
Debt Instrument [Line Items]
Debt instrument, interest rate terms					Any outstanding principal on the Term Loan Advances will accrue interest at a floating rate equal to the greater of (i) 9.50% per annum and (ii) the sum of 6.25% plus the prime rate, as published in The Wall Street Journal. As of December 31, 2022 and 2021, the interest rate was 13.75% and 9.5%, respectively. Interest payments are payable monthly following the funding of a Term Loan Advance. The Company will be required to make principal payments on the outstanding balance of the Term Loan Advances commencing on April 1, 2023 (the “Term Loan Amortization Date”) in 36 equal monthly installments, plus interest; provided that if the Company has achieved the milestones described above, then the Term Loan Amortization Date will be automatically extended to October 1, 2023 or April 1, 2024, as applicable.
Loan, floating interest rate					9.50%
Loan, interest rate						13.75%	9.50%
Loan, maturity date					Apr. 01, 2025
Loan, principal amount percentage					6.55%
Loan, prepayment fee percentage						1%
Loan, principal outstanding						$ 12,500
Loan, unamortized debt discount						800
Loan, interest expense						$ 1,900	$ 400
Loan, effective interest rate						19.50%
Loan, final maturity payment						$ (800)
Effective cash balance						$ 10,000			$ 10,000
Hercules Term Loan Agreement Member | Subsequent Event [Member]
Debt Instrument [Line Items]
Minimum qualified cash balance		2,250
Short-Term Debt, Average Outstanding Amount		7,500
Qualified cash balance		$ 2,250
Hercules Term Loan Agreement Member | Prime Rate [Member]
Debt Instrument [Line Items]
Loan, floating interest rate					6.25%
Hercules Term Loan Agreement Member | Minimum [Member]
Debt Instrument [Line Items]
Loan, prepayment fee percentage						2%
Minimum qualified cash balance						$ 6,300
Hercules Term Loan Agreement Member | Maximum [Member]
Debt Instrument [Line Items]
Aggregate principal amount of initial loan advance					$ 30,000	$ 30,000
Loan, prepayment fee percentage						3%
Minimum qualified cash balance						$ 10,000
Hercules Term Loan Agreement Member | Tranche 1 Advance [Member]
Debt Instrument [Line Items]
Aggregate principal amount of initial loan advance					12,500	12,500
Hercules Term Loan Agreement Member | Tranche 2 Advance [Member]
Debt Instrument [Line Items]
Aggregate principal amount of initial loan advance					7,500
Hercules Term Loan Agreement Member | Tranche 3 Advance [Member]
Debt Instrument [Line Items]
Aggregate principal amount of initial loan advance					$ 10,000
Loan Agreement [Member]
Debt Instrument [Line Items]
Loan, floating interest rate			5.25%
Loan, interest rate					5.75%
Loan, number of repayment installments | Installment			36
Loan, maturity date			Jan. 01, 2023
Loan, prepayment fee percentage			6%
Loan, principal outstanding					$ 6,700
Loan, unamortized debt discount						200
Loan, interest expense						$ 0	900
Loan, final maturity payment					(900)
Warrants issued to purchase shares of common stock | shares			1,021
Warrant exercise price per share | $ / shares			$ 440.80
Gain (loss) on extinguishment of debt					$ 100
Loan Agreement [Member] | Prime Rate [Member]
Debt Instrument [Line Items]
Loan, floating interest rate			2.50%
Loan Agreement [Member] | Minimum [Member]
Debt Instrument [Line Items]
Loan, prepayment fee percentage			1%
Loan Agreement [Member] | Maximum [Member]
Debt Instrument [Line Items]
Loan, prepayment fee percentage			3%
Loan Agreement [Member] | Initial Loan [Member]
Debt Instrument [Line Items]
Aggregate principal amount of initial loan advance			$ 15,000
Loan Agreement [Member] | PPP Loan [Member]
Debt Instrument [Line Items]
Loan, maturity date				Apr. 21, 2022
Gain (loss) on extinguishment of debt							$ 800
PPP Loan proceeds received				$ 800
Promissory note interest rate				1%

Debt - Schedule of Future Princ

Debt - Schedule of Future Principal Payments for Long-Term Debt (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Debt Disclosure [Abstract]
2023	$ 4,204
2024	6,101
2025	2,195
Total future principal payments	12,500
Less: unamortized discount	(782)
Carrying value of long-term debt	11,718
Less: current portion	(3,980)	$ 0
Add: final Term Loan fee due at maturity in 2023	(819)
Long-term portion	$ 8,557	$ 11,996

Related Parties - Additional In

Related Parties - Additional Information (Detail) - USD ($) $ in Thousands		12 Months Ended
	Aug. 29, 2013	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Schedule Of Related Party Transaction Details [Line Items]
Accrued expenses		$ 2,799	$ 4,196
Technion Research and Development Foundation Ltd [Member]
Schedule Of Related Party Transaction Details [Line Items]
Aggregate milestone payment		0	0
Technion Agreement [Member] | Technion Research and Development Foundation Ltd [Member]
Schedule Of Related Party Transaction Details [Line Items]
Research and development expense	$ 100	0	0
Accrued expenses			$ 0	$ 0
Aggregate milestone payment		$ 6,100

Advances From Collaboration P_2

Advances From Collaboration Partners, Legal, and Other Contingencies - Additional Information (Detail)	1 Months Ended			12 Months Ended
	Sep. 30, 2022 USD ($)	Mar. 31, 2022 USD ($)	May 31, 2021 USD ($)	Dec. 31, 2022 USD ($) Time	Dec. 31, 2021 USD ($)	Dec. 31, 2019 USD ($)
Legal And Other Contingencies [Line Items]
Due to Affiliate, Current				$ 12,535,000	$ 3,723,000
Royalties Percentage Of Net Sales Based On Actual Amount Of Funding				6%
Clinical and regulatory milestone payments received				$ 3,600,000
Royalties				0
Patent Expenses Due To Harvard				200,000
Advances from collaboration partners				$ 12,535,000	3,723,000
Two Thousand Nineteen Cystic Fibrosis Foundation Award [Member]
Legal And Other Contingencies [Line Items]
Due to Affiliate, Current					3,400,000
Advances from collaboration partners					3,400,000
Two Thousand Twenty Two Cystic Fibrosis Foundation Agreement [Member]
Legal And Other Contingencies [Line Items]
Number Of Times Amount Of Funds Received | Time				3
Two Thousand Twenty Two Cystic Fibrosis Foundation Agreement [Member] | Elox - Liabilities [Member]
Legal And Other Contingencies [Line Items]
Due to Affiliate, Current				$ 45,000
Embedded Derivative, Gain (Loss) on Embedded Derivative, Net				45,000
Advances from collaboration partners				45,000
Two Thousand Twenty One Cystic Fibrosis Foundation Award [Member]
Legal And Other Contingencies [Line Items]
Due to Affiliate, Current				$ 600,000	300,000
Number Of Times Amount Of Funds Received | Time				8
Advances from collaboration partners				$ 600,000	300,000
Elox - Cystic Fibrosis Foundation [Member] | Two Thousand Twenty Two Cystic Fibrosis Foundation Agreement [Member]
Legal And Other Contingencies [Line Items]
Aggregate Amount Of Milestone Payment	$ 1,500,000
Percentage Of Consideration Received For Disposition Event				10%
Elox - Cystic Fibrosis Foundation [Member] | Two Thousand Twenty One Cystic Fibrosis Foundation Award [Member]
Legal And Other Contingencies [Line Items]
Percentage Of Consideration Received For Disposition Event				20%
Percentage Of Sale Or License Event				10%
Elox - Cystic Fibrosis Foundation [Member] | Elox - Phase Two Clinical Development [Member] | Two Thousand Twenty Two Cystic Fibrosis Foundation Agreement [Member]
Legal And Other Contingencies [Line Items]
Upfront Payment Received		$ 7,000,000
Remaining Amount Of Award Payable Upon Achievement Certain Clinical Development Milestones				$ 7,400,000
Minimum [Member]
Legal And Other Contingencies [Line Items]
Percentage of obligated to remit Harvard fees				20%
Maximum [Member]
Legal And Other Contingencies [Line Items]
Percentage of obligated to remit Harvard fees				30%
Related party transaction percentage of expenses				5%
Maximum [Member] | Two Thousand Nineteen Cystic Fibrosis Foundation Award [Member]
Legal And Other Contingencies [Line Items]
Funding Award Amount Received						$ 3,600,000
Maximum [Member] | Two Thousand Twenty One Cystic Fibrosis Foundation Award [Member]
Legal And Other Contingencies [Line Items]
Funding Award Amount Received			$ 2,600,000
Maximum [Member] | Elox - Cystic Fibrosis Foundation [Member] | Elox - Phase Two Clinical Development [Member] | Two Thousand Twenty Two Cystic Fibrosis Foundation Agreement [Member]
Legal And Other Contingencies [Line Items]
Award To Fund Development Milestones Amount		$ 15,900,000
Research and Development Agreements [Member]
Legal And Other Contingencies [Line Items]
R&D grants received				$ 0	$ 0
Royalty payment as percentage of net sales				3%
Repayment percentage of grants received				100%
Royalty received including accrued LIBOR interest				$ 2,800,000
Research and Development Agreements [Member] | Israel Innovation Authority [Member]
Legal And Other Contingencies [Line Items]
R&D grants received				$ 2,600,000

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	May 13, 2021	Dec. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Dec. 31, 2020
Common stock, shares authorized		500,000,000	500,000,000
Common stock, par value		$ 0.01	$ 0.01
Common stock, shares outstanding		2,166,356	2,166,248
Preferred Stock, shares authorized		5,000,000	5,000,000
Preferred stock, par value		$ 0.01	$ 0.01
Preferred stock, shares issued		0	0
Preferred Stock, shares outstanding		0	0
Net proceeds from common stock shares issued at public offering		$ 0	$ 47,718
Common Stock [Member]
Common stock, shares outstanding		2,166,356	2,166,248		1,003,930
Underwritten Public Offering [Member] | Common Stock [Member]
Issuance of shares upon public offering, net of offering costs, shares	958,333
Common stock public offering price	$ 54
Net proceeds from common stock shares issued at public offering	$ 51,800
Underwriting discounts and commissions	3,100
Offering expenses	$ 800
Maximum [Member] | Sales Agreement [Member]
Sale of stock, authorized amount of common stock				$ 50,000

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Transaction Related to Warrants to Purchase Common Stock (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Stockholders' Equity Attributable to Parent [Abstract]
Warrants outstanding beginning balance, Shares	8,097
Warrants forfeited, Shares	7,076
Warrants outstanding ending balance, Shares	1,021	8,097
Warrants exercisable, Shares	1,021
Warrants outstanding beginning balance, Weighted average exercise price	$ 172.40
Forfeited	(59,320)
Warrants forfeited, Weighted average exercise price	$ 133.91
Warrants outstanding ending balance,Weighted average exercise price	440.80	$ 172.40
Forfeited	367.39
Warrants exercisable, Weighted average exercise price	$ 440.80
Warrants outstanding and exercisable Weighted average remaining contractual life	6 years 29 days	1 year 8 months 26 days
Warrants exercisable, Weighted average remaining contractual life	6 years 29 days

Stock-based Compensation - Addi

Stock-based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Apr. 20, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options to purchase common stock granted	86,112
Exercise price per share	$ 17.88
Unrecognized compensation cost related to outstanding options	$ 5.3
Unrecognized compensation cost expected to be recognized over a weighted-average period	2 years 5 months 4 days
Weighted average grant date fair value of options granted	$ 12.20	$ 62.40
2018 Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance			125,000
Contractual life of stock options granted	10 years
2018 Plan [Member] | Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercisable period of vested options		1 month
2018 Plan [Member] | Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercisable period of vested options	3 months

Stock-based Compensation - Tran

Stock-based Compensation - Transactions Related to Grant of Stock Options to Employees and Directors (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Amount
Options outstanding as of December 31, 2020	222,611
Granted	86,112
Exercised	0
Forfeited	(59,320)
Options outstanding as of December 31, 2021	249,403	222,611
Options exercisable at December 31, 2021	81,809
Weighted average exercise price per Share
Options outstanding as of December 31, 2020	$ 209.60
Granted	17.88
Exercised	0
Forfeited	367.39
Options outstanding as of December 31, 2021	105.87	$ 209.60
Options exercisable at December 31, 2021	$ 214.06
Weighted average remaining contractual life
Options outstanding	8 years 1 month 13 days	7 years 2 months 23 days
Options exercisable	6 years 4 months 20 days
Aggregate intrinsic value
Options outstanding	$ 3	$ 254
Options exercisable at December 31, 2021	$ 3

Stock-based Compensation - Assu

Stock-based Compensation - Assumptions Used to Estimate Fair Values of Stock Options Granted (Detail)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Dividend yield	0%	0%
Volatility, minimum	78%	76%
Volatility, maximum	82%	77%	80%	92%
Risk free interest rate, minimum	1.84%	0.87%
Risk free interest rate, maximum	3.96%	1.33%
Expected term (years)		6 years
Contractual term (years)	10 years	10 years
Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (years)	5 years 6 months
Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (years)	6 years		6 years	6 years

Stock-based Compensation - Tr_2

Stock-based Compensation - Transactions Related to Grant of Restricted Stock Units to Employees (Detail) - Restricted Stock Units [Member]	12 Months Ended
	Dec. 31, 2022 $ / shares shares
Amount
Unvested at December 31, 2020 | shares	157
Vested | shares	(157)
Unvested at December 31, 2021 | shares	0
Weighted average grant date fair value price
Unvested at December 31, 2020 | $ / shares	$ 600.80
Vested | $ / shares	600.80
Unvested at December 31, 2021 | $ / shares	$ 0

Stock-based Compensation - Summ

Stock-based Compensation - Summary of Allocated Stock-based Compensation Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 3,021	$ 9,167
Research and Development Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	1,319	1,336
General and Administrative Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 1,702	$ 7,831

Income Taxes - Components of In

Income Taxes - Components of Income (Loss) Before Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Line Items]
U.S.	$ (22,991)	$ (47,849)
Loss before taxes on income	(36,065)	(66,727)
Israel [Member]
Income Tax Disclosure [Line Items]
Israel	(13,074)	(18,895)
Australia
Income Tax Disclosure [Line Items]
Israel	$ 0	$ 17

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 19, 2017
Income Tax Disclosure [Line Items]
Taxes on income	$ 0	$ 0
Valuation allowance	79,977,000	71,589,000
Net deferred tax asset	0	0
Change in valuation allowance	8,400,000	19,000,000
Federal research tax credit carryforwards	$ 8,100,000	5,900,000	$ 700,000
Income tax examination, description	The Company is subject to income taxes in the United States and Israel and Australia. The Company files income tax returns in the U.S. and in several states. The federal and state tax returns are generally subject to tax examination by taxing authorities for tax years December 31, 2019 to present. To the extent the Company has tax attribute carryforwards, the tax years in which the attribute was generated may still be adjusted upon examination by the Internal Revenue Service or state tax authorities to the extent utilized in a future period. The Israeli income tax returns remain open to examination beginning in 2013 to present. The Australia income tax returns remain open to examination beginning in 2021 to present. If and when the Company claims NOL carryforwards from any prior years against future taxable income, those losses may be examined by the taxing authorities.
Earliest Tax Year [Member]
Income Tax Disclosure [Line Items]
Federal research tax credit expiry, beginning period	2026
Latest Tax Year [Member]
Income Tax Disclosure [Line Items]
Federal research tax credit expiry, beginning period	2041
Federal [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforwards	$ 159,200,000	158,800,000	$ 77,200,000
U.S. federal NOL carryforwards, not subject to expiration	$ 84,100,000
Net operating loss carryforwards eligible to offset taxable income, maximum	80%
Federal [Member] | Earliest Tax Year [Member]
Income Tax Disclosure [Line Items]
U.S. net operating loss expiry, beginning period	2023
Federal [Member] | Latest Tax Year [Member]
Income Tax Disclosure [Line Items]
U.S. net operating loss expiry, beginning period	2037
State [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforwards	$ 25,900,000	24,200,000
Israel Tax Authority [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforwards	$ 101,200,000	$ 99,300,000

Income Taxes - Significant Comp

Income Taxes - Significant Components of Deferred Tax Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Deferred tax assets:
Net operating loss carryforwards	$ 58,334	$ 57,716
Stock-based compensation	1,831	3,143
Reserves and allowances	170	337
U.S. tax credits and other credits	8,226	6,009
Capitalized research and development expenditures	11,184	3,988
Operating lease right-of-use assets	(197)	(338)
Operating lease liabilities	203	363
Other	226	371
Total deferred tax assets	79,977	71,589
Valuation allowance	(79,977)	(71,589)
Net deferred tax assets	$ 0	$ 0

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Expected Tax Expense with Actual Tax Expense (Detail)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
U.S. federal statutory rate	21%	21%
State tax rate, net of federal benefit	2.20%	1%
Permanent differences	(7.40%)	(7.30%)
Tax credits	6.60%	3.50%
Effect of rate differences from statutory	1%	0.60%
Change in valuation allowance	(23.40%)	(18.80%)
Income tax provision	0%	0%

Net Loss Per Share - Schedule o

Net Loss Per Share - Schedule of Loss and Weighted Average Number of Shares Used in Computing Basic and Diluted Net Loss Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Numerator:
Net loss	$ (36,065)	$ (66,727)
Denominator:
Weighted average number of shares of common stock used in computing net loss per share, basic	2,166,311	1,749,071
Weighted average number of shares of common stock used in computing net loss per share, diluted	2,166,311	1,749,071
Net loss per share, basic	$ (16.65)	$ (38.15)
Net loss per share, diluted	$ (16.65)	$ (38.15)

Net Loss Per Share - Additional

Net Loss Per Share - Additional Information (Detail) - shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Earnings Per Share [Abstract]
Shares excluded from the calculation of the diluted net loss per share	250,424	230,865

Other Expense (Income), net - S

Other Expense (Income), net - Schedule of Other Expense (Income) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Other Income and Expenses [Abstract]
Interest and other income	$ (274)	$ (8)
Interest and other expense	1,949	1,259
Foreign currency exchange losses (gains), net	3	(2)
Research and development tax credit income	(77)
Change In Fair Value Of Derivative Liabilities	45	0
Gain on debt extinguishment		(808)
Loss on debt extinguishment		268
Total other expense (income), net	$ 1,646	$ 709

Segment and Geographic Inform_2

Segment and Geographic Information - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2022 Segment Region
Segment Reporting [Abstract]
Number of operating segment | Segment	1
Number of geographic regions | Region	3

Marketable Securities - Summary

Marketable Securities - Summary of Cash, Cash Equivalents and Marketable Securities (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Schedule Of Available For Sale Securities [Line Items]
Cash and cash equivalents	$ 19,207	$ 42,268
Cash and cash equivalents, Fair Value		42,268
Total cash, cash equivalents and marketable securities, Amortized Cost		42,268
Total cash, cash equivalents and marketable securities, Fair Value		$ 42,268

Marketable Securities - Additio

Marketable Securities - Additional Information (Detail) - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Debt Securities, Available-for-Sale, Allowance for Credit Loss	$ 0	$ 0
marketable securities	$ 0

Merger Accounting - Additional

Merger Accounting - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands			12 Months Ended
		Apr. 01, 2021	Dec. 31, 2022	Dec. 31, 2021
Business Acquisition [Line Items]
Common stock, par value			$ 0.01	$ 0.01
Incurred and expensed costs related to merger			$ 0	$ 1,003
Zikani Therapeutics, Inc. [Member]
Business Acquisition [Line Items]
Date of acquisition		Apr. 01, 2021
Incurred and expensed costs related to merger				$ 1,000
Zikani Therapeutics, Inc. [Member] | Restricted Stock Units [Member]
Business Acquisition [Line Items]
Number of shares issued in Merger Agreement		11,054
Zikani Therapeutics, Inc. [Member] | Common Stock [Member]
Business Acquisition [Line Items]
Number of shares issued in Merger Agreement	[1]	189,920
Common stock, par value		$ 0.01
[1] The shares of common stock issued as merger consideration are unregistered and subject to trading restriction under Rule 144. The Company estimated the DLOM based on consideration of multiple valuation methods. A DLOM is applied to the Company’s quoted common stock price to estimate the value of Eloxx common stock issued on a minority, non-marketable basis. The Eloxx Common Stock issued was offered and sold in transactions exempt from registration under the Securities Act of 1933, as amended (the “Securities Act”), in reliance on Section 4(a)(2) thereof and Regulation D thereunder.

Merger Accounting - Summary of

Merger Accounting - Summary of Total Consideration for Merger (Detail) - Zikani Therapeutics, Inc. [Member]	Apr. 01, 2021 USD ($) $ / shares shares
Business Acquisition [Line Items]
Actual closing price per share of Company common stock as reported on the Nasdaq Global Market on April 1, 2021 | $ / shares	$ 134.40
Adjusted for a discount for lack of marketability (“DLOM”), percentage	87.50%	[1]
Adjusted for a discount for lack of marketability (“DLOM”)	$ 117.60	[1]
Fair value of common stock consideration	22,335,000
Transaction costs	1,003,000
Total purchase price	$ 23,338,000
Common Stock [Member]
Business Acquisition [Line Items]
Number of shares issued in Merger Agreement | shares	189,920	[1]
[1] The shares of common stock issued as merger consideration are unregistered and subject to trading restriction under Rule 144. The Company estimated the DLOM based on consideration of multiple valuation methods. A DLOM is applied to the Company’s quoted common stock price to estimate the value of Eloxx common stock issued on a minority, non-marketable basis. The Eloxx Common Stock issued was offered and sold in transactions exempt from registration under the Securities Act of 1933, as amended (the “Securities Act”), in reliance on Section 4(a)(2) thereof and Regulation D thereunder.

Merger Accounting - Summary o_2

Merger Accounting - Summary of Purchase Price Allocation (Detail) - Zikani Therapeutics, Inc. [Member] $ in Thousands	Apr. 01, 2021 USD ($)
Business Acquisition [Line Items]
Cash and cash equivalents	$ 1,954
Restricted cash	191
Prepaid expenses and other current assets	296
Operating lease right-of-use asset	1,810
Property and equipment, net	192	[1]
Intangible assets	467	[2]
Total Assets	4,910
Accounts payable	1,219
Accrued expenses	748
Current portion of operating lease liability	588
Operating lease liability	1,222
Total liabilities	3,777
Net assets acquired	1,133
In process research and development acquired	22,205	[3]
Purchase price	$ 23,338
[1] Zikani’s property and equipment consists principally of laboratory and computer equipment, furniture and fixtures and leasehold improvements. Employee-related intangible assets relate to Zikani’s assembled workforce acquired in the Zikani Merger. IPR&D represents the allocated consideration based on the estimated fair value of Zikani’s IPR&D. In accordance with ASC 730, Research and Development, the fair value of IPR&D acquired in an asset acquisition with no alternative future use be allocated a portion of the consideration transferred and charged to expense at the acquisition date.

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Assets and liabilities measured at fair value on a recurring basis (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds included in cash and cash equivalents		$ 42,268
Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Embedded derivatives	$ 45
Money Market Funds [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds included in cash and cash equivalents	18,737
Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds included in cash and cash equivalents	18,737
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Embedded derivatives	$ 45

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value of Financial Instruments - Summary of Rollforward of Fair Value of Embedded Derivatives (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Change in fair value of embedded derivative liabilities	$ 45,000	$ 0
Monte Carlo Simulation [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value of embedded derivatives, December 31, 2021	0
Change in fair value of embedded derivative liabilities	45,000
Fair value of embedded derivatives, December 31, 2022	$ 45,000	$ 0

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - USD ($) $ in Thousands	Sep. 01, 2023	Mar. 07, 2023	May 31, 2023	Dec. 31, 2022
Subsequent Event [Line Items]
Minimum qualified cash balance				$ 10,000
Maximum [Member]
Subsequent Event [Line Items]
Minimum qualified cash balance				$ 10,000
Subsequent Event [Member]
Subsequent Event [Line Items]
Outstanding principal value	$ 5,000	$ 7,500
Minimum qualified cash balance		$ 2,250	$ 0
Loan, maturity date		Apr. 01, 2025
Subsequent Event [Member] | Hercules Term Loan Agreement [Member]
Subsequent Event [Line Items]
Loan, maturity date		Apr. 01, 2025
Equity Method Investments			20,000
Subsequent Event [Member] | Maximum [Member]
Subsequent Event [Line Items]
Minimum qualified cash balance			10,000
Subsequent Event [Member] | Minimum [Member]
Subsequent Event [Line Items]
Minimum qualified cash balance			$ 6,300