X0202 SCHEDULE 13G 0001587114 XXXXXXXX LIVE Comon Stock 06/09/2026 0001035354 Eloxx Pharmaceuticals, Inc. 29014R301 P.O. BOX 274 ARLINGTON MA 02476 Rule 13d-1(b) Rule 13d-1(c) EcoR1 Capital, LLC a DE 0.00 403586.00 0.00 403586.00 403586.00 N 9.9 IA OO Percentage calculated based on (1) 400,000 shares of Common Stock beneficially owned by the reporting person and pre-funded warrants to acquire 50,000 shares of Common Stock, subject to a 9.99% beneficial ownership limitation, and (2) 4,036,314 shares of Common Stock outstanding following the completion of the offering of securities by the Issuer disclosed in the prospectus filed by the Issuer on June 9, 2026. Oleg Nodelman a X1 0.00 403586.00 0.00 403586.00 403586.00 N 9.9 HC IN Percentage calculated based on (1) 400,000 shares of Common Stock beneficially owned by the reporting person and pre-funded warrants to acquire 50,000 shares of Common Stock, subject to a 9.99% beneficial ownership limitation, and (2) 4,036,314 shares of Common Stock outstanding following the completion of the offering of securities by the Issuer disclosed in the prospectus filed by the Issuer on June 9, 2026. EcoR1 Capital Fund Qualified, L.P. DE 0.00 377635.00 0.00 377635.00 377635.00 N 9.3 PN Percentage calculated based on (1) 374,280 shares of Common Stock beneficially owned by the reporting person and pre-funded warrants to acquire 46,785 shares of Common Stock, subject to a 9.99% beneficial ownership limitation, and (2) 4,036,314 shares of Common Stock outstanding following the completion of the offering of securities by the Issuer disclosed in the prospectus filed by the Issuer on June 9, 2026. Eloxx Pharmaceuticals, Inc. P.O. Box 274, 10 Court Street, Arlington, MA 02476 EcoR1 Capital, LLC, a Delaware limited liability company ("EcoR1") EcoR1 Capital Fund Qualified, L.P., a Delaware limited partnership ("Qualified Fund") Oleg Nodelman Qualified Fund is filing this statement jointly with the other reporting persons, but not as a member of a group, and it expressly disclaims membership in a group. In addition, the filing of this Schedule 13G on behalf of Qualified Fund should not be construed as an admission that it is, and it disclaims that it is, a beneficial owner, as defined in Rule 13d-3 under the Act, of any securities covered by this Schedule 13G. Each reporting person also disclaims beneficial ownership of the securities reported herein except to the extent of that person's pecuniary interest therein. 357 Tehama Street #3 San Francisco, CA 94103 See Item 4 of the cover sheet for each reporting person. N IA HC EcoR1: 403,586 Oleg Nodelman: 403,586 Qualified Fund: 377,635 EcoR1: 9.9% Oleg Nodelman: 9.9% Qualified Fund: 9.3% EcoR1: 0 Oleg Nodelman: 0 Qualified Fund: 0 EcoR1: 403,586 Oleg Nodelman: 403,586 Qualified Fund: 377,635 EcoR1: 0 Oleg Nodelman: 0 Qualified Fund: 0 EcoR1: 403,586 Oleg Nodelman: 403,586 Qualified Fund: 377,635 Y Y Y N EcoR1 is the general partner and investment adviser of investment funds, including Qualified Fund. Mr. Nodelman is the control person of EcoR1. Y N By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11. By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11. EXHIBIT 99 - AGREEMENT REGARDING JOINT FILING OF STATEMENT ON SCHEDULE 13D OR 13G EcoR1 Capital, LLC /s/ Oleg Nodelman 06/16/2026 Oleg Nodelman /s/ Oleg Nodelman 06/16/2026 EcoR1 Capital Fund Qualified, L.P. /s/ Oleg Nodelman 06/16/2026