Eloxx Pharmaceuticals Announces First Patients Dosed in Phase 2b EXACT Study of Exaluren in Nonsense Mutation Alport Syndrome

• First two patients dosed in the EXACT study

• Topline data from the initial 16-week placebo-controlled portion of the study expected mid-2027; final readout expected by the end of 2027

ARLINGTON, Mass., Sept. 11, 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 first two patients have been dosed in the EXACT Study, a Phase 2b clinical trial evaluating exaluren in patients with nonsense mutation Alport syndrome (NMAS).

"Dosing the first patients in the EXACT Study is an important milestone for Eloxx and, more importantly, for the Alport syndrome community, where no FDA-approved therapy currently addresses the underlying genetic cause of disease," said Sumit Aggarwal, President and Chief Executive Officer of Eloxx. "This trial reflects our continued commitment to patients with nonsense mutation Alport syndrome, and we look forward to advancing exaluren through this Phase 2b study with topline data expected in mid-2027."

"Dosing the first patients in the EXACT Study is a significant step for people living with nonsense mutation Alport syndrome, a disease with a clear genetic cause but no approved treatment that addresses it directly," said Professor Daniel Gale, Professor of Nephrology at University College London and Consultant Nephrologist at the Royal Free London NHS Foundation Trust. "Patients with this form of Alport syndrome can progress to kidney failure while still in their twenties, so there is real urgency behind bringing genetically targeted therapies like exaluren into clinical testing. Advancing this trial is an important step forward for a patient population that has been underserved for too long."

The EXACT study is a randomized, placebo-controlled, delayed start, global Phase 2b clinical trial designed to evaluate the safety and efficacy of exaluren in patients with NMAS caused by nonsense mutations in COL4A3, COL4A4, or COL4A5 in 24 patients. The trial's initial portion is placebo-controlled over 16 weeks with a primary efficacy endpoint for non-U.S. pediatric patients and all adult patients is to evaluate the effect of exaluren on structural changes in podocyte FPE as measured by change in FSD in kidney biopsiesTopline data from this portion is expected mid-2027 and a final readout at 32 weeks is expected by the end of 2027.

Nonsense mutation Alport syndrome is a rare, inherited kidney disease caused by nonsense mutations in the COL4A3, COL4A4, or COL4A5 genes, which prevent normal production of type IV collagen, a key structural protein of the kidney's filtration barrier. Approximately 7% of Alport syndrome patients carry these nonsense mutations, which are associated with a more severe prognosis than missense mutations and a mean age of kidney failure of approximately 20 years. The disease is characterized by progressive kidney damage, including podocyte injury, hematuria, proteinuria, and kidney failure. There is currently no FDA-approved therapy that addresses the underlying genetic cause of NMAS.

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 the treatment of rare kidney diseases, including nonsense mutation Alport syndrome, for which it is being evaluated in the Phase 2b EXACT Study, and autosomal dominant polycystic kidney disease (ADPKD), for which a Phase 2 clinical trial is planned. The FDA and European Commission have granted orphan drug designation to exaluren for the treatment of Alport syndrome, and the European Commission has granted orphan medicinal product designation to exaluren for the treatment of ADPKD.

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 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.

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 a planned Phase 2 clinical trial in ADPKD; 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.