UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K/A

Amendment No. 1

For the fiscal year ended December 31, 2017

OR

For the transition period from                  to                 

Commission file number: 001-31326

ELOXX PHARMACEUTICALS, INC.

(Exact Name of Registrant as Specified in Its Charter)

950 Winter Street

Waltham, Massachusetts 02451

(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:

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

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 if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K.  ☐

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T during the preceding 12 months (or for such shorter period that the registrant was required to submit and post 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. (Check one):

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 is a shell company (as defined in Rule 12b-2 of the Act).    Yes  ☐    No  ☒

The aggregate market value of the voting and non-voting common equity held by non-affiliates of the registrant, based on the closing price for such stock as reported on the OTCQB Market on June 30, 2017, the last business day of the registrant’s most recently completed second quarter, was: $7,092,700.

As of December 31, 2017, there were 27,527,738 shares of the Registrant’s common stock, par value $0.01 per share, outstanding.

EXPLANATORY NOTE

Eloxx Pharmaceuticals, Inc. (the “Company,” “we,” “our,” and “us”) is filing this Amendment No. 1 to Annual Report on Form 10-K/A (this “Amendment No. 1”) to amend its Annual Report on Form 10-K for the fiscal year ended December 31, 2017, as originally filed with the U.S. Securities and Exchange Commission (the “SEC”) on March 16, 2018 (the “Original Form 10-K”) solely to refile Exhibit 10.1 to the Original Form 10-K in response to comments received from the SEC regarding a confidential treatment request submitted to the SEC with respect to certain portions of Exhibit 10.1 of Item 15 of Part IV of the Original Form 10-K, which is hereby amended to include a revised redacted version of Exhibit 10.1. In addition, as required by Rule 12b-15 under the Securities Exchange Act of 1934, as amended, new certifications by our principal executive officer and principal financial officer required in accordance with Rule 13a-14(a) are being filed as exhibits to this Amendment No. 1; however, paragraphs 3, 4 and 5 of the certifications have been omitted because this Amendment No. 1 does not contain any financial statements nor does it contain or amend any disclosure with respect to Items 307 and 308 of Regulation S-K.

Except as described above, no other changes have been made to the Original Form 10-K. This Amendment No. 1 speaks as of the filing date of the Original Form 10-K and does not reflect events occurring after the filing date of the Original Form 10-K or modify or update any of the other information contained in the Original Form 10-K in any way other than as required to reflect the amendment discussed above. Accordingly, this Amendment No. 1 should be read in conjunction with the Original Form 10-K and the Company’s filings made with the SEC subsequent to the filing of the Original Form 10-K, including any amendments to such filings.

Part IV

Item 15. Exhibits and Financial Statement Schedules.

The following documents are filed as part of this Amendment No. 1 to the Annual Report on Form 10-K/A or as part of our Annual Report on Form 10-K filed with the SEC on March 16, 2018.

(a) Documents filed as part of this report.

The following documents are filed as part of this report:

1. Exhibits

The exhibits listed in the accompanying index to exhibits are filed as part of, or incorporated by reference into, this report.

2

EXHIBIT INDEX

3

4

5

SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this Annual Report on Form 10-K/A to be signed on its behalf by the undersigned, thereunto duly authorized.

Date: April 19, 2018

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