ET-700 Targets Simpler Wilson Disease Dosing in Pilot Trial

Eton Pharmaceuticals has dosed the first patient in a pilot clinical study of ET-700, its proprietary extended-release zinc acetate formulation for Wilson disease, signaling a direct challenge to the established three-times-daily dosing burden that has defined maintenance therapy in this rare, lifelong condition. For formulation scientists and regulatory strategists tracking 505(b)(2) pathways, the study design and endpoint selection carry as much weight as the topline data expected in the second half of 2026.

The double-blinded, placebo-controlled trial, conducted by the Department of Hepatology and Gastroenterology at Aarhus University Hospital in Denmark, enrolls 36 healthy volunteers across three arms: GALZIN 50 mg three times daily, ET-700 75 mg twice daily plus placebo once daily, and placebo three times daily. The primary endpoint measures change in mean hepatic 64Cu standard uptake value, assessed via PET imaging with the radioactive tracer 64CuCl2, comparing intestinal copper absorption across groups before and after a four-week treatment period. The use of 64Cu PET as a quantitative biomarker reflects a methodologically rigorous approach to demonstrating bioequivalence of mechanism in a small-N pilot setting.

Study investigator Dr. Thomas Sandahl, Clinical Professor of Hepatology at Aarhus University, noted that the study is designed to assess whether an extended-release zinc formulation can reduce intestinal copper absorption with a simpler dosing regimen. If topline results are positive, Eton has indicated a pivotal study would follow in early 2027, placing a potential NDA submission on a timeline relevant to current FDA rare disease review cycles. Formulation teams should note that ET-700 carries a patent-pending designation, and any 505(b)(2) strategy will need to account for the existing GALZIN labeling, including its contraindication for symptomatic patients requiring initial chelation therapy and documented post-marketing signals for copper deficiency and gastric ulcer with long-term zinc acetate use.

Source: Eton Pharmaceuticals press release via GlobeNewswire, April 27, 2026.