Eloxx Pharmaceuticals Announces FDA Clearance of Investigational New Drug Application for Exaluren in Nonsense-Mutation ADPKD

• FDA clearance of the IND enables Eloxx to open U.S. clinical sites for EXPRESS, its global Phase 2 study of exaluren in nonsense-mutation ADPKD
• EXPRESS will randomize approximately 60 patients 1:1 to exaluren or placebo for 52 weeks, with annualized htTKV growth as the primary endpoint; first patient dosing expected in 3Q 2027 and topline data in 1H 2029
• FDA pre-IND feedback indicated that a substantial and durable htTKV effect could support Breakthrough Therapy Designation; FDA also lists htTKV as a potential surrogate endpoint for accelerated approval in ADPKD

ARLINGTON, Mass., Oct. 29, 2026 /PRNewswire/ -- Eloxx Pharmaceuticals, Inc. (Nasdaq: ELOX), a clinical-stage biopharmaceutical company developing exaluren for the treatment of rare kidney diseases, today announced that the U.S. Food and Drug Administration (FDA) has cleared the Company's Investigational New Drug (IND) application for exaluren for the treatment of nonsense-mutation autosomal dominant polycystic kidney disease (ADPKD). The IND clearance enables Eloxx to initiate EXPRESS, its global Phase 2 clinical trial, at clinical sites in the United States.

EXPRESS Phase 2 Study

EXPRESS is designed to enroll approximately 60 adults with genetically confirmed PKD1 or PKD2 nonsense mutations, randomized 1:1 to exaluren or placebo for 52 weeks. The primary endpoint is the annualized rate of change in height-adjusted total kidney volume (htTKV), assessed by MRI at baseline and Weeks 28, 36 and 52. Eloxx is now activating sites in the United States and other countries ahead of planned first patient dosing in 3Q 2027. Topline 52-week results are expected in 1H 2029.

Regulatory Pathway

In written pre-IND feedback, FDA noted that a substantial and durable htTKV treatment effect, with supporting eGFR and safety data, could serve as a potential basis for Breakthrough Therapy Designation. FDA also identifies change in htTKV as a potential surrogate endpoint for accelerated approval in ADPKD. Exaluren holds orphan drug designation for ADPKD in the United States and Europe. Any expedited pathway or designation would depend on clinical results and further FDA discussions.

"IND clearance is an important milestone for people living with nonsense-mutation ADPKD, who have no therapy that addresses the genetic cause of their disease," said Sumit Aggarwal, President and Chief Executive Officer of Eloxx. "With the trial design finalized, our focus now is execution: activating sites and preparing to dose the first patient in the third quarter of 2027."

About Nonsense Mutation ADPKD

Autosomal dominant polycystic kidney disease is the most common inherited kidney disease, affecting an estimated 160,000 to 200,000 people in the United States. It is caused by mutations in PKD1 or PKD2, which encode the proteins polycystin-1 and polycystin-2. An estimated 26% of PKD1 and PKD2 mutations are nonsense mutations. Loss of functional polycystin leads to the progressive formation and enlargement of fluid-filled kidney cysts, increasing kidney volume and causing a steady decline in kidney function. ADPKD is a leading genetic cause of kidney failure.

About Exaluren

Exaluren is Eloxx's investigational, small-molecule ribosomal modulator designed to promote readthrough of premature stop codons caused by nonsense mutations, enabling production of full-length, functional protein. Exaluren is being developed for rare kidney diseases caused by nonsense mutations, including nonsense mutation Alport syndrome and nonsense mutation autosomal dominant polycystic kidney disease (ADPKD). The FDA and the European Commission have each granted orphan drug designations to exaluren for the treatment of Alport syndrome and ADPKD.

About Eloxx Pharmaceuticals

Eloxx Pharmaceuticals, Inc. (Nasdaq: ELOX) is a clinical-stage biopharmaceutical company developing novel, small-molecule product candidates designed to modulate the ribosome and promote readthrough of premature stop codons induced by nonsense mutations to enable the production of full-length proteins. Eloxx's lead product candidate, exaluren, is being developed for the treatment of rare kidney diseases, including nonsense mutation Alport syndrome and nonsense mutation autosomal dominant polycystic kidney disease (ADPKD). Eloxx has also exclusively licensed its product candidate, ZKN-013, to Almirall, S.A., which is developing it for the treatment of rare dermatological diseases associated with nonsense mutations.

For more information, please visit www.eloxxpharma.com.

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. All statements other than statements of present and historical facts contained in this press release, including without limitation statements regarding the expected timing of the initiation of, and results from, clinical trials of the Company's product candidates, including the Phase 2b clinical trial of exaluren in nonsense mutation Alport syndrome and the EXPRESS Phase 2 clinical trial of exaluren in nonsense mutation ADPKD; the FDA's clearance of the Company's IND for exaluren and the anticipated initiation of the EXPRESS trial in the United States; the design of the EXPRESS trial and the potential for exaluren to receive Breakthrough Therapy designation or pursue accelerated approval; the potential benefits of orphan drug designation; the Company's collaboration with Almirall and the potential to receive milestone and royalty payments; and the potential of the Company's product candidates to treat nonsense mutations, are forward-looking statements. Forward-looking statements can be identified by words such as "aim," "may," "will," "expect," "plan," "anticipate," "could," "intend," "target," "project," "believe," "estimate," "potential," "seeks," or "continue," or the negative of these terms or other similar expressions, although not all forward-looking statements contain these words. Forward-looking statements are based on management's current plans, estimates, assumptions and projections, and are subject to known and unknown risks, uncertainties and assumptions, and actual results may differ materially from those expressed or implied due to various important factors, including, but not limited to, the Company's need for and ability to obtain additional capital; the uncertainty and expense of clinical development; the fact that results from preclinical studies and early clinical trials are not necessarily predictive of future results; and other important factors discussed under the caption "Risk Factors" and elsewhere in the Company's Quarterly Report on Form 10-Q for the quarterly period ended June 30, 2026 and its other filings with the SEC, accessible on the SEC's website at www.sec.gov and on the "Financials & Filings" page of the Company's website. All forward-looking statements speak only as of the date of this press release and, except as required by applicable law, the Company undertakes no obligation to update or revise any forward-looking statements contained herein.

Contact

Investor Relations
Eloxx Pharmaceuticals, Inc.
[email protected]
(781) 577-5300

SOURCE Eloxx Pharmaceuticals, Inc.