Eloxx Pharmaceuticals (ELOX) 10-Q 16 Aug 21 2021 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2021	Aug. 09, 2021
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Trading Symbol	ELOX
Entity Registrant Name	ELOXX PHARMACEUTICALS, INC.
Entity Central Index Key	0001035354
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		86,202,772
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
Entity Incorporation, State or Country Code	DE
Entity Shell Company	false
Entity Current Reporting Status	Yes
Title of 12(b) Security	Common Stock, $0.01 par value per share
Entity Interactive Data Current	Yes
Security Exchange Name	NASDAQ
Document Quarterly Report	true
Document Transition Report	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 56,734	$ 24,668
Restricted cash	246	56
Prepaid expenses and other current assets	1,579	1,169
Total current assets	58,559	25,893
Property and equipment, net	185	133
Operating lease right-of-use asset	1,866	421
Other long-term assets		30
Total assets	60,610	26,477
Current liabilities:
Accounts payable	2,024	481
Accrued expenses	3,302	2,886
Current portion of long-term debt	5,686	5,239
Advances from collaboration partners	3,411	805
Current portion of operating lease liability	753	389
Taxes payable	34	38
Total current liabilities	15,210	9,838
Long-term debt	3,637	6,376
Operating lease liability	1,120	33
Total liabilities	19,967	16,247
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.01 par value per share, 5,000,000 shares authorized, no shares issued or outstanding as of June 30, 2021 and December 31, 2020
Common stock, $0.01 par value per share, 500,000,000 shares authorized, 86,463,355 and 40,350,922 shares issued and 86,201,767 and 40,157,187 shares outstanding as of June 30, 2021 and December 31, 2020, respectively	863	404
Common stock in treasury, at cost, 261,588 and 193,735 shares as of June 30, 2021 and December 31, 2020, respectively	(2,065)	(1,828)
Additional paid-in capital	258,193	183,250
Accumulated deficit	(216,348)	(171,596)
Total stockholders’ equity	40,643	10,230
Total liabilities and stockholders’ equity	$ 60,610	$ 26,477

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2021	Dec. 31, 2020
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	86,463,355	40,350,922
Common stock, shares outstanding	86,201,767	40,157,187
Common stock, treasury shares	261,588	193,735

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Operating expenses:
Research and development	$ 5,704	$ 3,738	$ 9,777	$ 8,505
General and administrative	7,355	3,848	11,696	8,854
In process research and development	22,670		22,670
Restructuring charges				3,994
Total operating expenses	35,729	7,586	44,143	21,353
Loss from operations	(35,729)	(7,586)	(44,143)	(21,353)
Other expense, net	329	301	609	480
Net loss	$ (36,058)	$ (7,887)	$ (44,752)	$ (21,833)
Net loss per share, basic and diluted	$ (0.54)	$ (0.20)	$ (0.84)	$ (0.54)
Weighted average number of shares of common stock used in computing net loss per share, basic and diluted	66,389,865	40,129,304	53,357,401	40,101,789
Comprehensive loss:
Net loss	$ (36,058)	$ (7,887)	$ (44,752)	$ (21,833)
Other comprehensive income:
Change in unrealized gain on available-for-sale securities		(52)		(5)
Comprehensive loss	$ (36,058)	$ (7,939)	$ (44,752)	$ (21,838)

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities:
Net loss	$ (44,752)	$ (21,833)
Adjustments to reconcile net loss to net cash used in operating activities:
Acquired in-process research and development	22,670
Stock-based compensation	5,343	5,971
Depreciation	56	36
Amortization of operating lease right-of-use asset	423	246
Amortization of debt discount	208	301
Amortization, net of premiums and discounts on investments		9
Loss on sales and disposals of property and equipment	84
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(84)	(449)
Accounts payable	(75)	(1,101)
Accrued expenses	69	(1,170)
Merger related costs paid	(1,003)
Operating lease liabilities	(417)	(245)
Taxes payable	(4)	(5)
Net cash used in operating activities	(17,482)	(18,240)
Cash flows from investing activities:
Proceeds from maturities of marketable securities		27,000
Cash acquired in merger transaction	2,145
Cash received from long-term deposits		42
Net cash provided by investing activities	2,145	27,042
Cash flows from financing activities:
Proceeds from underwritten public offerings, net of issuance costs	47,718
Proceeds from debt financing obligation		797
Repayment of term loan principal	(2,500)	(2,083)
Payment for settlement of taxes upon vesting of restricted stock units	(237)	(119)
Proceeds from advances from collaboration partners	2,606	402
Proceeds from exercises of stock options	6	64
Net cash provided by (used in) financing activities	47,593	(939)
Increase (decrease) in cash, cash equivalents and restricted cash	32,256	7,863
Cash, cash equivalents and restricted cash at the beginning of the period	24,724	22,536
Cash, cash equivalents and restricted cash at the end of the period	56,980	30,399
Reconciliation of cash, cash equivalents and restricted cash to condensed consolidated balance sheets:
Cash and cash equivalents	56,734	30,347
Restricted cash	246	52
Cash, cash equivalents and restricted cash at the end of the period	56,980	30,399
Supplemental disclosure of cash flow activities:
Issuance of common stock in merger transaction	22,335
Cash paid for interest	273	481
Cash paid for income taxes	$ 2	$ 5

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income [Member]	Treasury stock [Member]	Accumulated deficit [Member]
Balance at Dec. 31, 2019	$ 36,213	$ 402	$ 174,515	$ 18	$ (1,703)	$ (137,019)
Balance, shares at Dec. 31, 2019		40,030,763			(155,706)
Exercise of stock options	64		64
Exercise of stock options, shares		10,636
Vesting of restricted stock units	(116)	$ 1	(1)		$ (116)
Vesting of restricted stock units, shares		84,055			(34,874)
Stock-based compensation expense	3,995		3,995
Change in unrealized gain (loss) on investments	47			47
Net loss	(13,946)					(13,946)
Balance at Mar. 31, 2020	26,257	$ 403	178,573	65	$ (1,819)	(150,965)
Balance, shares at Mar. 31, 2020		40,125,454			(190,580)
Balance at Dec. 31, 2019	36,213	$ 402	174,515	18	$ (1,703)	(137,019)
Balance, shares at Dec. 31, 2019		40,030,763			(155,706)
Change in unrealized gain (loss) on investments	(5)
Net loss	(21,833)
Balance at Jun. 30, 2020	20,291	$ 403	180,549	13	$ (1,822)	(158,852)
Balance, shares at Jun. 30, 2020		40,135,290			(191,616)
Balance at Mar. 31, 2020	26,257	$ 403	178,573	65	$ (1,819)	(150,965)
Balance, shares at Mar. 31, 2020		40,125,454			(190,580)
Vesting of restricted stock units	(3)				$ (3)
Vesting of restricted stock units, shares		9,836			(1,036)
Stock-based compensation expense	1,976		1,976
Change in unrealized gain (loss) on investments	(52)			(52)
Net loss	(7,887)					(7,887)
Balance at Jun. 30, 2020	20,291	$ 403	180,549	$ 13	$ (1,822)	(158,852)
Balance, shares at Jun. 30, 2020		40,135,290			(191,616)
Balance at Dec. 31, 2020	$ 10,230	$ 404	183,250		$ (1,828)	(171,596)
Balance, shares at Dec. 31, 2020	40,157,187	40,157,187			(193,735)
Vesting of restricted stock units	$ (94)				$ (94)
Vesting of restricted stock units, shares		57,687			(23,883)
Stock-based compensation expense	1,308		1,308
Net loss	(8,694)					(8,694)
Balance at Mar. 31, 2021	2,750	$ 404	184,558		$ (1,922)	(180,290)
Balance, shares at Mar. 31, 2021		40,214,874			(217,618)
Balance at Dec. 31, 2020	$ 10,230	$ 404	183,250		$ (1,828)	(171,596)
Balance, shares at Dec. 31, 2020	40,157,187	40,157,187			(193,735)
Exercise of stock options, shares	3,525
Net loss	$ (44,752)
Balance at Jun. 30, 2021	$ 40,643	$ 863	258,193		$ (2,065)	(216,348)
Balance, shares at Jun. 30, 2021	86,201,767	86,201,767			(261,588)
Balance at Mar. 31, 2021	$ 2,750	$ 404	184,558		$ (1,922)	(180,290)
Balance, shares at Mar. 31, 2021		40,214,874			(217,618)
Exercise of stock options	6		6
Exercise of stock options, shares		3,525
Vesting of restricted stock units	(143)				$ (143)
Vesting of restricted stock units, shares		53,224			(43,970)
Stock-based compensation expense	4,035		4,035
Issuance of common stock in connection with merger	22,335	$ 76	22,259
Issuance of common stock in connection with merger, shares		7,596,810
Issuance of shares upon public offering	47,718	$ 383	47,335
Issuance of shares upon public offering, shares		38,333,334
Net loss	(36,058)					(36,058)
Balance at Jun. 30, 2021	$ 40,643	$ 863	$ 258,193		$ (2,065)	$ (216,348)
Balance, shares at Jun. 30, 2021	86,201,767	86,201,767			(261,588)

Nature of the Business

Nature of the Business	6 Months Ended
	Jun. 30, 2021
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 developing novel ribonucleic acid (RNA)-modulating drug candidates, each designed to be a eukaryotic ribosomal selective glycoside (ERSG), for the treatment of rare and ultra-rare premature stop codon diseases. Premature stop codons are point mutations that disrupt the stability of the impacted messenger RNA (mRNA) and the protein synthesis from that mRNA. 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 TM The Company is headquartered in Watertown, Massachusetts, with an additional office in Rehovot, Israel. Liquidity and Going Concern The Company has a history of net losses and negative cash flows from operating activities since its inception and, as of June 30, 2021, had an accumulated deficit of $216.3 million. The Company expects to continue to incur net losses and use cash in 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 it does, the Company will need to continue raising additional capital to fund its operations. The Company believes that its cash and cash equivalents of $56.7 million at June 30, 2021 will enable it to meet anticipated cash needs required to maintain its current and planned operations through at least the next 12 months from the issuance of the financial statements for the quarter ended June 30, 2021. 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. If the Company is unable to obtain adequate financing, it will evaluate options which may include reducing or deferring operating expenses, including curtailing its workforce and certain development programs, which would have a material adverse effect on the Company’s operations and future prospects.

Basis of Presentation and Signi

Basis of Presentation and Significant Accounting Policies	6 Months Ended
	Jun. 30, 2021
Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies	2. Basis of Presentation and Significant Accounting Policies The Company has prepared the accompanying unaudited interim condensed 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 (“ASU”) promulgated by the Financial Accounting Standards Board (“FASB”). The Company has reclassified certain items from the prior year’s condensed consolidated financial statements to conform to the current year’s presentation. Specifically, the Company allocated certain facilities and support costs between research and development expenses and general and administrative expenses that were previously reported within general and administrative expenses only. For the three and six months ended June 30, 2020, $0.2 million and $0.4 million, respectively, is reclassified from general and administrative expenses to research and development expenses, which resulted in general and administrative expenses decreasing from $4.0 million to $3.8 million and $9.3 million to $8.9 million, for the three and six months ended June 30, 2020, respectively, and research and development expenses increasing from $3.5 million to $3.7 million and $8.1 million to $8.5 million, for the three and six months ended June 30, 2020, respectively. This reclassification had no impact on previously reported total operating expenses, loss from operations, net loss, or net cash used in operating activities. Certain information and footnote disclosures normally included in the Company’s annual consolidated financial statements have been condensed or omitted, as permitted by such rules and regulations. These interim consolidated financial statements, in the opinion of management, reflect all normal recurring adjustments necessary for a fair presentation of the Company’s financial position, results of operations, and cash flows for the interim periods ended June 30, 2021 and 2020. The results of operations for the interim periods are not necessarily indicative of the results of operations to be expected for the full year. These interim condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements as of and for the year ended December 31, 2020, and the notes thereto, which are included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2020, filed with the U.S. Securities and Exchange Commission (the “SEC”) on March 12, 2021 (the “Annual Report”). The significant accounting policies used in the preparation of these condensed consolidated financial statements are consistent with those described in the Company’s audited consolidated financial statements as of and for the year ended December 31, 2020, and the notes thereto, in the Company’s Annual Report. Recent Accounting Pronouncements Although the FASB has issued several ASUs for which adoption dates are pending, the Company does not expect any to have any impacts on its consolidated financial statements.

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	6 Months Ended
	Jun. 30, 2021
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): June 30, 2021 December 31, 2020 Research and development $ 751 $ 631 Insurance 283 170 Other 545 368 Total $ 1,579 $ 1,169

Property and Equipment

Property and Equipment	6 Months Ended
	Jun. 30, 2021
Property Plant And Equipment [Abstract]
Property and Equipment	4. Property and Equipment Property and equipment, net consisted of the following (in thousands): June 30, 2021 December 31, 2020 Computers and software $ 31 $ 124 Office furniture and equipment 28 164 Laboratory equipment 176 - Leasehold improvements 65 158 300 446 Less accumulated depreciation (115 ) (313 ) Property and equipment, net $ 185 $ 133 Depreciation expense was $40 thousand and $17 thousand for the three months ended June 30, 2021 and 2020, and $56 thousand and $36 thousand for the six months ended June 30, 2021 and 2020, respectively.

Accrued Expenses

Accrued Expenses	6 Months Ended
	Jun. 30, 2021
Payables And Accruals [Abstract]
Accrued Expenses	5. Accrued Expenses Accrued expenses consisted of the following (in thousands): June 30, 2021 December 31, 2020 Research and development expenses $ 1,499 $ 802 Payroll and other employee-related expenses 1,017 1,315 Professional services 686 415 Interest on debt 48 57 Other 52 39 Restructuring — 258 Total $ 3,302 $ 2,886

Debt

Debt	6 Months Ended
	Jun. 30, 2021
Debt Disclosure [Abstract]
Debt	6. Debt 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 “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 June 30, 2021, the interest rate was 5.75%. The Company commenced making payments on the outstanding principal In conjunction with the initial loan advance, the Company issued warrants to the Lenders to purchase an aggregate of 40,834 shares of common stock at a price of $11.02 (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. The Company granted first priority liens and a security interest in substantially all of the Company’s assets, excluding all of its intellectual property, which is subject to a negative pledge, and a pledge by the Company of the shares of one of its wholly-owned subsidiaries as collateral for the obligations thereunder. The Loan Agreement also contains customary covenants, including limitations on other indebtedness, liens, acquisitions, investments and dividends, and events of default, including payment defaults, breaches of covenants, a material impairment in the perfection or priority of the security interest in the collateral, and events relating to bankruptcy or insolvency. As of June 30, 2021, the carrying value of the outstanding loan consists of $7.9 million in principal less an unamortized debt discount of $0.3 million. The debt issuance costs, the valuation of the warrants, and the final maturity payment of $0.9 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 three months ended June 30, 2021 and 2020 was $0.2 million and $0.3 million, respectively. Interest expense is calculated using the effective interest method and is inclusive of non-cash amortization of the debt discount. At June 30, 2021, the effective interest rate was 10.85%. 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 has a maturity date of April 21, 2022 and an interest rate of 1.0% per annum. Monthly payments of principal and interest are due beginning on September 21, 2021, although interest accrues from the issuance date. A PPP loan may be partially or entirely forgiven based on employee retention for the 24-week period starting on the loan date through October 2020, and the use of loan proceeds for payroll or other specified costs during the same period. Forgiveness is also based on the employer maintaining or restoring headcount and maintaining salary levels. Forgiveness is reduced if headcount declines or if salaries decrease. Any loan forgiveness will be made subject to SVB approval in accordance with SBA requirements. The Company’s scheduled future principal payments for the long-term debt are as follows (in thousands): June 30, 2021 Remainder of 2021 $ 2,898 2022 5,398 2023 417 Total future principal payments 8,713 Less unamortized discount (290 ) Carrying value of long-term debt 8,423 Less current portion (5,686 ) Add final fee due at maturity in 2023 900 Long-term portion $ 3,637

Legal and Other Contingencies

Legal and Other Contingencies	6 Months Ended
	Jun. 30, 2021
Commitments And Contingencies Disclosure [Abstract]
Legal and Other Contingencies	7. Legal and Other 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. The Company accounts for its contingent liabilities in accordance with ASC Topic 450, “Contingencies”. During 2019, the Company received a funding award from the Cystic Fibrosis Foundation (“CFF”) and entered into an agreement relating to the award, which agreement was amended in December 2020 providing for an additional award amount. Payment of award amounts are subject to the achievement of certain milestones in connection with the Company’s 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. 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 June 30, 2021, and December 31, 2020, the Company received payments of $3.4 million and $0.8 million, respectively, which are recorded as liabilities captioned 'Advances from collaboration partners' in the accompanying condensed consolidated financial statements. During May 2021, the Company received a n additional award from the CFF 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, and, in the event of a disposition of the underlying asset. As of June 30, 2021 , the Company had not received any funds associated with this award.

Stockholders' Equity

Stockholders' Equity	6 Months Ended
	Jun. 30, 2021
Equity [Abstract]
Stockholders' Equity	8. Stockholders’ Equity Warrants As of June 30, 2021 and December 31, 2020, 323,892 warrants to purchase common stock were outstanding, with a weighted average exercise price of $4.31 per share. The weighted average remaining contractual life at June 30, 2021 was 2.24 years.

Stock-based Compensation

Stock-based Compensation	6 Months Ended
	Jun. 30, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-based Compensation	9. Stock-based Compensation Summary of Stock Option Activity Transactions related to stock options awarded to employees and directors during the six months ended June 30, 2021 were as follows: Shares Weighted average exercise price Weighted average remaining contractual life (years) Aggregate intrinsic value Options outstanding at December 31, 2020 3,803,061 $ 10.16 8.20 $ 1,936,183 Granted 4,662,867 2.74 Exercised (3,525 ) (1.59 ) Forfeited (807,395 ) (5.00 ) Options outstanding at June 30, 2021 7,655,008 $ 6.19 7.45 $ 1,346,198 Options exercisable at June 30, 2021 2,719,909 $ 11.49 3.78 $ 413,252 The aggregate intrinsic value represents the total intrinsic value (the difference between the fair value of the common stock as of June 30, 2021 and the exercise price, multiplied by the number of in-the-money options) that would have been received by the option holders had all option holders exercised their options on June 30, 2021. This amount is impacted by changes in the fair value of the common stock. Summary of Restricted Stock Unit Activity Activity related to restricted stock units awarded to employees during the six months ended June 30, 2021 were as follows: Shares Weighted average grant date fair value per share Unvested at December 31, 2020 349,725 $ 4.67 Granted 542,679 $ 3.36 Vested (178,762 ) $ 4.71 Forfeited (78,750 ) 3.97 Unvested at June 30, 2021 634,892 $ 3.63 Stock-based Compensation Stock-based compensation relates, non-employee directors and non-employees, time-based restricted stock units granted and performance-based stock options and restricted stock units granted. In February 2020, the Board of Directors approved a leadership and organizational realignment, which accelerated the vesting of certain awards, resulting in additional stock-based compensation of $2.1 million, which was recorded in restructuring charges. In connection with the acquisition of Zikani, on April 1, 2021, Martijn Kleijwegt, Silvia Noiman and Gregory Williams resigned from the Board of Directors. The Company incurred a one-time non-cash stock compensation charge, relating to accelerated vesting of executive stock awards of $2.4 million. Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Research and development $ 114 $ 262 $ 355 $ 481 General and administrative 3,921 1,714 4,988 3,366 Restructuring charges — — — 2,124 Total stock-based compensation expense $ 4,035 $ 1,976 $ 5,343 $ 5,971

Marketable Securities

Marketable Securities	6 Months Ended
	Jun. 30, 2021
Investments Debt And Equity Securities [Abstract]
Marketable Securities	10. Marketable Securities Cash and cash equivalents at June 30, 2021 and December 31, 2020 had an amortized cost as well as fair value of $56.7 million and $24.7 million, respectively. As of June 30, 2021 and December 31, 2020, no credit losses were identified related to the cash equivalents or marketable securities.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	6 Months Ended
	Jun. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	11. Fair Value of Financial Instruments At June 30, 2021 and December 31, 2020, the Company’s financial assets valued based on Level 1 inputs consisted of cash and cash equivalents. During the three and six months ended June 30, 2021, the Company did not have any transfers of financial assets between levels, as defined in the significant accounting policies note in our Annual Report. 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 accounts payable, accrued expenses, lease obligation liability and debt, approximate their fair values due to the short-term nature of these instruments.

Other Expense, Net

Other Expense, Net	6 Months Ended
	Jun. 30, 2021
Other Income And Expenses [Abstract]
Other Expense, Net	12. Other Expense, Net Other expense, net consisted of the following (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Interest and other expense $ 319 $ 347 $ 579 $ 762 Interest and other income — (69 ) — (313 ) Foreign currency exchange losses 10 12 30 22 Investment income — 11 — 9 Total other expense, net $ 329 $ 301 $ 609 $ 480

Net Loss Per Share

Net Loss Per Share	6 Months Ended
	Jun. 30, 2021
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 periods, are as follows (amounts in thousands, except share and per share data): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Numerator: Net loss $ (36,058 ) $ (7,887 ) $ (44,752 ) $ (21,833 ) Denominator: Weighted average number of shares of common stock used in computing net loss per share, basic and diluted 66,389,865 40,129,304 53,357,401 40,101,789 Net loss per share, basic and diluted $ (0.54 ) $ (0.20 ) $ (0.84 ) $ (0.54 ) The following potentially dilutive securities have been excluded from the computation of diluted weighted average shares outstanding as their effect would be anti-dilutive: Six Months Ended June 30, 2021 2020 Options to purchase common stock 7,655,008 4,952,230 Restricted stock units 634,892 367,167 Warrants 323,892 323,894 Total potential common stock equivalents 8,613,792 5,643,291

Restructuring

Restructuring	6 Months Ended
	Jun. 30, 2021
Restructuring And Related Activities [Abstract]
Restructuring	14. Restructuring In February 2020, the Company eliminated 13 full-time positions. This resulted in a charge of $4.0 million, including $2.1 million in stock-based compensation expense, with severance being paid over one year. The accrued charges and associated payments for the three months ended June 30, 2021, are as follows (in thousands): Beginning Balance Additions Deductions Ending Balance Severance and related costs $ 258 $ — $ (258 ) $ — Total restructuring charges $ 258 $ — $ (258 ) $ — The accrued charges and associated payments for the three months ended June 30, 2020 are as follows (in thousands): Beginning Balance Additions Deductions Ending Balance Severance and related costs $ — $ 1,705 $ (747 ) $ 958 Contract termination costs — 165 (165 ) — Total restructuring charges $ — $ 1,870 $ (912 ) $ 958

Merger Accounting

Merger Accounting	6 Months Ended
	Jun. 30, 2021
Business Combinations [Abstract]
Merger Accounting	15. Merger Accounting On April 1, 2021, the Company, acquired Zikani, pursuant to an Agreement and Plan of Merger (the “Merger Agreement”). Under the terms of the Merger Agreement, the Company issued 7,596,810 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 442,142 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 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 acquisition of Zikani, 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) 7,597 Actual closing price per share of Company common stock as reported on the Nasdaq Capital Market on April 1, 2021 $ 3.36 Adjusted for a discount for lack of marketability (“DLOM”) (1) 87.5 % $ 2.94 Estimated fair value of common stock consideration 22,335 Estimated transaction costs 1,003 Total preliminary estimated 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 preliminary allocation of the cost of the acquisition to the respective assets acquired and liabilities assumed, based on their relative fair values. The purchase price allocations were prepared on a preliminary basis and are subject to change as additional information becomes available concerning the fair value of the assets acquired and liabilities assumed. Any measurement period adjustments to the purchase price allocation will be made as soon as practicable but no later than one year from the date of acquisition. 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 (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 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. The actual purchase price allocated to IPR&D may change, subject to finalization of the fair value estimates and the determination of final transaction costs. The final valuation of the IPR&D consideration could differ significantly from the current estimate. In addition, the Company incurred and expensed costs directly related to the Merger totaling approximately $1.0 million, of which $0.8 million and $1.0 million was incurred in the three and six months ended June 30, 2021, and is included in general and administrative expenses in the condensed consolidated statement of operations and comprehensive loss. Since the closing date of the Merger, the results of Zikani’s operations have been included in the Company’s condensed consolidated financial statements.

Basis of Presentation and Sig_2

Basis of Presentation and Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2021
Accounting Policies [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements Although the FASB has issued several ASUs for which adoption dates are pending, the Company does not expect any to have any impacts on its consolidated financial statements.

Prepaid Expenses and Other Cu_2

Prepaid Expenses and Other Current Assets (Tables)	6 Months Ended
	Jun. 30, 2021
Prepaid And Other Current Assets [Abstract]
Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consisted of the following (in thousands): June 30, 2021 December 31, 2020 Research and development $ 751 $ 631 Insurance 283 170 Other 545 368 Total $ 1,579 $ 1,169

Property and Equipment (Tables)

Property and Equipment (Tables)	6 Months Ended
	Jun. 30, 2021
Property Plant And Equipment [Abstract]
Property and equipment, net	Property and equipment, net consisted of the following (in thousands): June 30, 2021 December 31, 2020 Computers and software $ 31 $ 124 Office furniture and equipment 28 164 Laboratory equipment 176 - Leasehold improvements 65 158 300 446 Less accumulated depreciation (115 ) (313 ) Property and equipment, net $ 185 $ 133

Accrued Expenses (Tables)

Accrued Expenses (Tables)	6 Months Ended
	Jun. 30, 2021
Payables And Accruals [Abstract]
Accrued expenses	Accrued expenses consisted of the following (in thousands): June 30, 2021 December 31, 2020 Research and development expenses $ 1,499 $ 802 Payroll and other employee-related expenses 1,017 1,315 Professional services 686 415 Interest on debt 48 57 Other 52 39 Restructuring — 258 Total $ 3,302 $ 2,886

Debt (Tables)

Debt (Tables)	6 Months Ended
	Jun. 30, 2021
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): June 30, 2021 Remainder of 2021 $ 2,898 2022 5,398 2023 417 Total future principal payments 8,713 Less unamortized discount (290 ) Carrying value of long-term debt 8,423 Less current portion (5,686 ) Add final fee due at maturity in 2023 900 Long-term portion $ 3,637

Stock-based Compensation (Table

Stock-based Compensation (Tables)	6 Months Ended
	Jun. 30, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Transactions Related to Stock Options Awarded to Employees and Directors	Transactions related to stock options awarded to employees and directors during the six months ended June 30, 2021 were as follows: Shares Weighted average exercise price Weighted average remaining contractual life (years) Aggregate intrinsic value Options outstanding at December 31, 2020 3,803,061 $ 10.16 8.20 $ 1,936,183 Granted 4,662,867 2.74 Exercised (3,525 ) (1.59 ) Forfeited (807,395 ) (5.00 ) Options outstanding at June 30, 2021 7,655,008 $ 6.19 7.45 $ 1,346,198 Options exercisable at June 30, 2021 2,719,909 $ 11.49 3.78 $ 413,252
Activity Related to Restricted Stock Units Awarded to Employees	Activity related to restricted stock units awarded to employees during the six months ended June 30, 2021 were as follows: Shares Weighted average grant date fair value per share Unvested at December 31, 2020 349,725 $ 4.67 Granted 542,679 $ 3.36 Vested (178,762 ) $ 4.71 Forfeited (78,750 ) 3.97 Unvested at June 30, 2021 634,892 $ 3.63
Summary of Allocated Stock-based Compensation Expense	Total equity-based compensation expense related to all of the Company’s stock-based awards was recognized as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Research and development $ 114 $ 262 $ 355 $ 481 General and administrative 3,921 1,714 4,988 3,366 Restructuring charges — — — 2,124 Total stock-based compensation expense $ 4,035 $ 1,976 $ 5,343 $ 5,971

Other Expense, Net (Tables)

Other Expense, Net (Tables)	6 Months Ended
	Jun. 30, 2021
Other Income And Expenses [Abstract]
Schedule of Other Expense, Net	Other expense, net consisted of the following (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Interest and other expense $ 319 $ 347 $ 579 $ 762 Interest and other income — (69 ) — (313 ) Foreign currency exchange losses 10 12 30 22 Investment income — 11 — 9 Total other expense, net $ 329 $ 301 $ 609 $ 480

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	6 Months Ended
	Jun. 30, 2021
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 periods, are as follows (amounts in thousands, except share and per share data): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Numerator: Net loss $ (36,058 ) $ (7,887 ) $ (44,752 ) $ (21,833 ) Denominator: Weighted average number of shares of common stock used in computing net loss per share, basic and diluted 66,389,865 40,129,304 53,357,401 40,101,789 Net loss per share, basic and diluted $ (0.54 ) $ (0.20 ) $ (0.84 ) $ (0.54 )
Potentially Dilutive Securities Excluded from Computation of Diluted Weighted Average Shares Outstanding	The following potentially dilutive securities have been excluded from the computation of diluted weighted average shares outstanding as their effect would be anti-dilutive: Six Months Ended June 30, 2021 2020 Options to purchase common stock 7,655,008 4,952,230 Restricted stock units 634,892 367,167 Warrants 323,892 323,894 Total potential common stock equivalents 8,613,792 5,643,291

Restructuring (Tables)

Restructuring (Tables)	6 Months Ended
	Jun. 30, 2021
Restructuring And Related Activities [Abstract]
Summary of Accrued Charges and Associated Payments	The accrued charges and associated payments for the three months ended June 30, 2021, are as follows (in thousands): Beginning Balance Additions Deductions Ending Balance Severance and related costs $ 258 $ — $ (258 ) $ — Total restructuring charges $ 258 $ — $ (258 ) $ — The accrued charges and associated payments for the three months ended June 30, 2020 are as follows (in thousands): Beginning Balance Additions Deductions Ending Balance Severance and related costs $ — $ 1,705 $ (747 ) $ 958 Contract termination costs — 165 (165 ) — Total restructuring charges $ — $ 1,870 $ (912 ) $ 958

Merger Accounting (Tables)

Merger Accounting (Tables)	6 Months Ended
	Jun. 30, 2021
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) 7,597 Actual closing price per share of Company common stock as reported on the Nasdaq Capital Market on April 1, 2021 $ 3.36 Adjusted for a discount for lack of marketability (“DLOM”) (1) 87.5 % $ 2.94 Estimated fair value of common stock consideration 22,335 Estimated transaction costs 1,003 Total preliminary estimated 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 preliminary allocation of the cost of the acquisition to the respective assets acquired and liabilities assumed, based on their relative fair values. The purchase price allocations were prepared on a preliminary basis and are subject to change as additional information becomes available concerning the fair value of the assets acquired and liabilities assumed. Any measurement period adjustments to the purchase price allocation will be made as soon as practicable but no later than one year from the date of acquisition. 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 (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 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. The actual purchase price allocated to IPR&D may change, subject to finalization of the fair value estimates and the determination of final transaction costs. The final valuation of the IPR&D consideration could differ significantly from the current estimate.

Nature of the Business - Additi

Nature of the Business - Additional Information (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Accumulated deficit	$ (216,348)	$ (171,596)
Cash, cash equivalents and marketable securities	$ 56,700	$ 24,700

Basis of Presentation and Sig_3

Basis of Presentation and Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Accounting Policies [Line Items]
Research and development expenses		$ 3,700		$ 8,500
General and administrative	$ 7,355	3,848	$ 11,696	8,854
Revision of Prior Period, Reclassification, Adjustment [Member]
Accounting Policies [Line Items]
Research and development expenses		200		400
Previously Reported [Member]
Accounting Policies [Line Items]
Research and development expenses		3,500		8,100
General and administrative		$ 4,000		$ 9,300

Prepaid Expenses and Other Cu_3

Prepaid Expenses and Other Current Assets - Schedule of Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Research and development	$ 751	$ 631
Insurance	283	170
Other	545	368
Total	$ 1,579	$ 1,169

Property and Equipment - Proper

Property and Equipment - Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Cost	$ 300	$ 446
Less accumulated depreciation	(115)	(313)
Property and equipment, net	185	133
Computers and software [Member]
Property, Plant and Equipment [Line Items]
Cost	31	124
Office furniture and equipment [Member]
Property, Plant and Equipment [Line Items]
Cost	28	164
Laboratory equipment [Member]
Property, Plant and Equipment [Line Items]
Cost	176
Leasehold improvement [Member]
Property, Plant and Equipment [Line Items]
Cost	$ 65	$ 158

Property and Equipment - Additi

Property and Equipment - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Property Plant And Equipment [Abstract]
Depreciation expenses	$ 40	$ 17	$ 56	$ 36

Accrued Expenses - Accrued Expe

Accrued Expenses - Accrued Expenses (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Payables And Accruals [Abstract]
Research and development expenses	$ 1,499	$ 802
Payroll and other employee-related expenses	1,017	1,315
Professional services	686	415
Interest on debt	48	57
Other	52	39
Restructuring		258
Total	$ 3,302	$ 2,886

Debt - Additional Information (

Debt - Additional Information (Detail) $ / shares in Units, $ in Thousands	Jan. 30, 2019USD ($)Installment$ / sharesshares	Apr. 30, 2020USD ($)	Jun. 30, 2021USD ($)$ / sharesshares	Jun. 30, 2020USD ($)	Dec. 31, 2020$ / sharesshares
Debt Instrument [Line Items]
Aggregate principal amount of initial loan advance			$ 8,423
Warrants issued to purchase shares of common stock | shares			323,892		323,892
Warrant exercise price | $ / shares			$ 4.31		$ 4.31
Loan, principal outstanding			$ 8,713
Loan, unamortized debt discount			290
Loan, final maturity payment			$ 900
Loan Agreement [Member]
Debt Instrument [Line Items]
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.
Debt instrument, payment terms	The Company commenced making payments on the outstanding principal balance of the loan on February 1, 2020, which is payable in 36 equal monthly installments and fully matures
Loan, floating interest rate	5.25%
Loan, interest rate			5.75%
Loan, frequency of periodic payment	monthly
Loan, number of repayment installments | Installment	36
Loan, periodic principal and interest payment commencement date	Feb. 1, 2020
Loan, maturity date	Jan. 1, 2023
Warrant exercise price | $ / shares	$ 11.02
Loan, prepayment fee percentage	6.00%
Loan, principal outstanding			$ 7,900
Loan, unamortized debt discount			300
Loan, interest expense			$ 200	$ 300
Loan, effective interest rate			10.85%
Loan, final maturity payment			$ 900
Loan Agreement [Member] | Minimum [Member]
Debt Instrument [Line Items]
Loan, prepayment fee percentage	1.00%
Loan Agreement [Member] | Maximum [Member]
Debt Instrument [Line Items]
Loan, prepayment fee percentage	3.00%
Loan Agreement [Member] | Prime Rate [Member]
Debt Instrument [Line Items]
Loan, floating interest rate	2.50%
Loan Agreement [Member] | Initial Loan [Member]
Debt Instrument [Line Items]
Aggregate principal amount of initial loan advance	$ 15,000
Warrants issued to purchase shares of common stock | shares	40,834
Loan Agreement [Member] | PPP Loan [Member]
Debt Instrument [Line Items]
Loan, periodic principal and interest payment commencement date		Sep. 21, 2021
Loan, maturity date		Apr. 21, 2022
PPP Loan proceeds received		$ 800
Promissory note interest rate		1.00%

Debt - Schedule of Future Princ

Debt - Schedule of Future Principal Payments for Long-Term Debt (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
Remainder of 2021	$ 2,898
2022	5,398
2023	417
Total future principal payments	8,713
Less unamortized discount	(290)
Carrying value of long-term debt	8,423
Less current portion	(5,686)	$ (5,239)
Add final fee due at maturity in 2023	900
Long-term portion	$ 3,637	$ 6,376

Legal and Other Contingencies -

Legal and Other Contingencies - Additional Information (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Advances from collaboration partners	$ 3,411	$ 805

Stockholder's Equity - Addition

Stockholder's Equity - Additional Information (Detail) - $ / shares	6 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Stockholders Equity [Abstract]
Number of common stock in warrant	323,892	323,892
Warrant exercise price	$ 4.31	$ 4.31
Weighted average remaining contractual life	2 years 2 months 26 days

Stock-based Compensation - Tran

Stock-based Compensation - Transactions Related to Stock Options Awarded to Employees and Directors (Detail)	6 Months Ended	12 Months Ended
	Jun. 30, 2021USD ($)$ / sharesshares	Dec. 31, 2020USD ($)$ / sharesshares
Amount
Options outstanding at December 31, 2020 | shares	3,803,061
Granted | shares	4,662,867
Exercised | shares	(3,525)
Forfeited | shares	(807,395)
Options outstanding at June 30, 2021 | shares	7,655,008	3,803,061
Options exercisable at June 30, 2021 | shares	2,719,909
Weighted average exercise price
Options outstanding at December 31, 2020 | $ / shares	$ 10.16
Granted | $ / shares	2.74
Exercised | $ / shares	(1.59)
Forfeited | $ / shares	(5)
Options outstanding at June 30, 2021 | $ / shares	6.19	$ 10.16
Options exercisable at June 30, 2021 | $ / shares	$ 11.49
Weighted average remaining contractual life
Options outstanding	7 years 5 months 12 days	8 years 2 months 12 days
Options exercisable	3 years 9 months 10 days
Aggregate intrinsic value
Options outstanding | $	$ 1,346,198	$ 1,936,183
Options exercisable | $	$ 413,252

Stock-based Compensation - Acti

Stock-based Compensation - Activity Related to Restricted Stock Units Awarded to Employees (Detail) - Restricted Stock Units [Member]	6 Months Ended
	Jun. 30, 2021$ / sharesshares
Amount
Unvested at December 31, 2020 | shares	349,725
Granted | shares	542,679
Vested | shares	(178,762)
Forfeited | shares	(78,750)
Unvested at June 30, 2021 | shares	634,892
Weighted average grant date fair value price
Unvested at December 31, 2020 | $ / shares	$ 4.67
Granted | $ / shares	3.36
Vested | $ / shares	4.71
Forfeited | $ / shares	3.97
Unvested at June 30, 2021 | $ / shares	$ 3.63

Stock-based Compensation - Addi

Stock-based Compensation - Additional Information (Detail) - USD ($) $ in Thousands	Apr. 01, 2021	Feb. 29, 2020	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Additional stock-based compensation			$ 4,035	$ 1,976	$ 5,343	$ 5,971
Restructuring Charges [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Additional stock-based compensation		$ 2,100				$ 2,124
Restructuring Charges [Member] | Zikani Therapeutics, Inc. [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Additional stock-based compensation	$ 2,400

Stock-based Compensation - Summ

Stock-based Compensation - Summary of Allocated Stock-based Compensation Expense (Detail) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Feb. 29, 2020	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense		$ 4,035	$ 1,976	$ 5,343	$ 5,971
Research and Development Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense		114	262	355	481
General and Administrative Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense		$ 3,921	$ 1,714	$ 4,988	3,366
Restructuring Charges [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 2,100				$ 2,124

Marketable Securities - Additio

Marketable Securities - Additional Information (Detail) - USD ($)	Jun. 30, 2021	Dec. 31, 2020
Investments Debt And Equity Securities [Abstract]
Cash and cash equivalent, Amortized cost	$ 56,700,000	$ 24,700,000
Cash, cash equivalents and marketable securities	56,700,000	24,700,000
Credit losses related to the cash equivalents or marketable securities	$ 0	$ 0

Fair Value of Financial Instr_2

Fair Value of Financial Instruments - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2021
Fair Value Disclosures [Abstract]
Transfers of financial assets between level 2 and level 3	the Company did not have any transfers of financial assets between levels

Other Expense, Net - Schedule o

Other Expense, Net - Schedule of Other Expense, Net (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Other Income And Expenses [Abstract]
Interest and other expense	$ 319	$ 347	$ 579	$ 762
Interest and other income		(69)		(313)
Foreign currency exchange losses	10	12	30	22
Investment income		11		9
Total other expense, net	$ 329	$ 301	$ 609	$ 480

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	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Numerator:
Net loss	$ (36,058)	$ (8,694)	$ (7,887)	$ (13,946)	$ (44,752)	$ (21,833)
Denominator:
Weighted average number of shares of common stock used in computing net loss per share, basic and diluted	66,389,865		40,129,304		53,357,401	40,101,789
Net loss per share, basic and diluted	$ (0.54)		$ (0.20)		$ (0.84)	$ (0.54)

Net Loss Per Share - Potentiall

Net Loss Per Share - Potentially Dilutive Securities Excluded from Computation of Diluted Weighted Average Shares Outstanding (Detail) - shares	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total potential common stock equivalents	8,613,792	5,643,291
Options to Purchase Common Stock [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total potential common stock equivalents	7,655,008	4,952,230
Restricted Stock Units [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total potential common stock equivalents	634,892	367,167
Warrants [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total potential common stock equivalents	323,892	323,894

Restructuring - Additional Info

Restructuring - Additional Information (Detail) $ in Millions	1 Months Ended
	Feb. 29, 2020USD ($)Employee
Restructuring And Related Activities [Abstract]
Elimination of full-time positions | Employee	13
Severance costs, charge	$ 4
Severance costs, stock-based compensation expense	$ 2.1
Restructuring and related costs, severance cost payment period	1 year

Restructuring - Summary of Accr

Restructuring - Summary of Accrued Charges and Associated Payments (Detail) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Restructuring Cost And Reserve [Line Items]
Beginning Balance	$ 258
Additions		$ 1,870
Deductions	(258)	(912)
Ending Balance		958
Severance and Related Costs [Member]
Restructuring Cost And Reserve [Line Items]
Beginning Balance	258
Additions		1,705
Deductions	$ (258)	(747)
Ending Balance		958
Contract Termination Costs [Member]
Restructuring Cost And Reserve [Line Items]
Additions		165
Deductions		$ (165)

Merger Accounting - Additional

Merger Accounting - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Apr. 01, 2021	Jun. 30, 2021	Jun. 30, 2021	Dec. 31, 2020
Business Acquisition [Line Items]
Common stock, par value		$ 0.01	$ 0.01	$ 0.01
Incurred and expensed costs related to merger			$ 1,003
Zikani Therapeutics, Inc. [Member]
Business Acquisition [Line Items]
Date of acquisition	Apr. 1, 2021
Incurred and expensed costs related to merger		$ 800	$ 1,000
Zikani Therapeutics, Inc. [Member] | Restricted Stock Units [Member]
Business Acquisition [Line Items]
Number of shares issued in Merger Agreement	442,142
Zikani Therapeutics, Inc. [Member] | Common Stock [Member]
Business Acquisition [Line Items]
Number of shares issued in Merger Agreement	7,596,810
Common stock, par value	$ 0.01

Merger Accounting - Summary of

Merger Accounting - Summary of Total Consideration for Merger (Detail) - Zikani Therapeutics, Inc. [Member]	Apr. 01, 2021USD ($)$ / sharesshares
Business Acquisition [Line Items]
Actual closing price per share of Company common stock as reported on the Nasdaq Capital Market on April 1, 2021 | $ / shares	$ 3.36
Adjusted for a discount for lack of marketability (“DLOM”), percentage	87.50%
Adjusted for a discount for lack of marketability (“DLOM”)	$ 2,940
Estimated fair value of common stock consideration	22,335,000
Estimated transaction costs	1,003,000
Total preliminary estimated purchase price	$ 23,338,000
Common Stock [Member]
Business Acquisition [Line Items]
Number of shares issued in Merger Agreement | shares	7,596,810

Merger Accounting - Summary o_2

Merger Accounting - Summary of Purchase Price Allocation (Detail) - Zikani Therapeutics, Inc. [Member] $ in Thousands	Apr. 01, 2021USD ($)
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
Intangible assets	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	22,205
Purchase price	$ 23,338