Eloxx Pharmaceuticals, Inc.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

For the fiscal years ended December 31, 2023, 2024 and 2025

OR

For the transition period from to

Commission file number:001-31326

ELOXX PHARMACEUTICALS, INC.

(Exact Name of Registrant as Specified in Its Charter)

P.O. Box 274

10 Court Street

Arlington, MA 02476

(Address of Principal Executive Offices and Zip Code)

(781)577-5300

(Registrant’s Telephone Number, Including Area Code)

Securities registered pursuant to Section 12(b) of the Act: None

Securities registered pursuant to Section 12(g) of the Act:

Indicate by check mark if the Registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes☐ No ☒

Indicate by check mark if the Registrant is not required to file reports pursuant to Section 13 or 15(d) of the Act. Yes☐ No ☒

Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes☐ No ☒

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes☐ No ☒

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See definitions of “accelerated filer”, “large accelerated filer”, “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report☐

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements.☐

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b).☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). Yes☐ No☒

The aggregate market value of the voting stock held by non-affiliates of the registrant on June 30, 2025, the last business day of the registrant’s most recently completed second quarter, was $330.00, based on the closing price for such stock as reported on the OTC Expert Market on that date.

As of March 12, 2026, there were 5,071,935 shares of the Registrant’s common stock, par value $0.01 per share, outstanding.

ELOXX PHARMACEUTICALS, INC.

TABLE OF CONTENTS

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Explanatory Note

Eloxx Pharmaceuticals, Inc. (“Eloxx”) is filing this comprehensive Annual Report on Form 10-K for the years ended December 31, 2023, 2024 and 2025 (the “Annual Report”) as part of its effort to become current in its filing obligations under the Securities Exchange Act of 1934, as amended (the “Exchange Act”). This Annual Report is Eloxx’s first periodic filing with the Securities and Exchange Commission (the “SEC”) since filing the quarterly report on Form 10-Q for the quarterly period ended September 30, 2023, filed on November 13, 2023. Included in this Annual Report are our audited financial statements for the fiscal years ended December 31, 2023, 2024 and 2025, which have not been previously filed with the SEC.