Arlington, Massachusetts, U.S., September 11, 2026
Eloxx Pharmaceuticals has announced that the first two patients have been dosed in the Phase 2b EXACT Study, a clinical trial evaluating its investigational therapy exaluren in people with nonsense mutation Alport syndrome (NMAS). The milestone marks the advancement of exaluren into a controlled mid-stage clinical study targeting a rare genetic kidney disease for which there is currently no FDA-approved therapy that directly addresses the underlying genetic cause. The global EXACT Study is designed to evaluate the safety and efficacy of exaluren in patients whose Alport syndrome is caused by nonsense mutations in the COL4A3, COL4A4, or COL4A5 genes.
Phase 2b EXACT Study Advances Clinical Development
The EXACT Study is a randomized, placebo-controlled, delayed-start, global Phase 2b clinical trial planned to enroll 24 patients with nonsense mutation Alport syndrome. The initial portion of the study will include a 16-week placebo-controlled period, providing investigators with an opportunity to assess the biological and clinical effects of exaluren against placebo. The primary efficacy endpoint for non-U.S. pediatric patients and all adult patients will evaluate structural changes in kidney podocytes, specialized cells that play an essential role in maintaining the kidney’s filtration barrier. Researchers will assess changes in foot process effacement (FPE) through kidney biopsy measurements of foot process density (FSD). Topline results from this initial portion are expected in mid-2027, while the final 32-week readout is expected by the end of 2027.The initiation of patient dosing represents an important milestone in the development of a potential genetically targeted treatment for NMAS. Rather than simply managing consequences of progressive kidney damage, exaluren is being developed to address the molecular consequences of nonsense mutations. The company’s clinical development program is therefore focused on determining whether the investigational mechanism can produce meaningful biological effects in patients with the disease.
Exaluren Targets Nonsense Mutations
Nonsense mutation Alport syndrome is a rare inherited kidney disorder caused by genetic changes that introduce premature stop signals into genes responsible for producing type IV collagen. This collagen is an important structural component of the kidney’s filtration barrier. According to Eloxx, approximately 7% of people with Alport syndrome carry these nonsense mutations, which are associated with a more severe disease course. Patients may experience progressive kidney injury, hematuria, proteinuria and eventually kidney failure, with the mean age of kidney failure reported at approximately 20 years for this mutation group. Exaluren is an investigational small-molecule ribosomal modulator designed to promote readthrough of premature stop codons caused by nonsense mutations. The intended mechanism is to enable cells to produce full-length, functional proteins despite the presence of the premature genetic stop signal. This approach is being evaluated clinically in NMAS and represents a potential precision-medicine strategy for diseases driven by specific genetic mutations. However, the effectiveness and clinical benefit of exaluren in patients with NMAS remain to be established through ongoing clinical development.
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Rare Disease Program Moves Toward Key Data Readouts
Eloxx’s development of exaluren extends beyond Alport syndrome. The company is also developing the investigational therapy for autosomal dominant polycystic kidney disease (ADPKD), with a Phase 2 clinical trial planned. Exaluren has received orphan drug designation from the U.S. FDA and European Commission for Alport syndrome, while the European Commission has also granted orphan medicinal product designation for its development in ADPKD. The upcoming mid-2027 topline data from the EXACT Study will therefore represent an important clinical-development milestone. Results from the placebo-controlled period should provide additional information about exaluren’s biological activity, safety and potential effects on disease-related kidney changes. Until those data become available, exaluren remains an investigational therapy, and its ability to alter the progression of nonsense mutation Alport syndrome has not yet been established.
Source: Eloxx Pharmaceuticals press release
