Crystalys Therapeutics Expands Phase 3 RUBY Study to Europe for Gout Treatment Dotinurad
Key Insights
Crystalys Therapeutics (search) has initiated patient dosing at European clinical sites for its Phase 3 RUBY study evaluating dotinurad, a next-generation URAT1 (search) inhibitor for gout treatment.
The randomized, double-blind study will enroll approximately 500 patients with hyperuricemia associated with gout, receiving once-daily oral dotinurad for up to 64 weeks.
Dotinurad is being developed as a second-line therapy for patients who do not respond adequately to allopurinol, addressing a critical treatment gap in gout management.
Crystalys Therapeutics (search) announced that the first patients have been dosed at clinical sites in Europe in its Phase 3 RUBY study evaluating dotinurad, a next-generation, once-daily oral URAT1 (search) inhibitor for the treatment of hyperuricemia associated with gout. The expansion represents a key milestone in the company's global Phase 3 clinical development program for dotinurad as a potential second-line treatment option for patients with gout who do not respond adequately to allopurinol.
"Expanding patient dosing into European sites is a key milestone for the RUBY study and we look forward to continued progress as enrollment advances," said James Mackay, Ph.D., President and Chief Executive Officer of Crystalys Therapeutics (search).
Phase 3 RUBY Study Design
The RUBY study (NCT07089875) is a Phase 3, randomized, double-blind, multicenter study designed to evaluate the safety and efficacy of dotinurad in approximately 500 patients with hyperuricemia associated with gout. Study participants will receive dotinurad orally once a day for up to 64 weeks.
The trial is part of Crystalys' broader global Phase 3 clinical development program aimed at advancing dotinurad toward regulatory approval and commercial launch in Western markets.
Addressing Critical Treatment Gap in Gout Management
Gout represents the most common form of inflammatory arthritis, characterized by sudden, severe attacks of pain, swelling, redness and tenderness in one or more joints. The condition arises from excess uric acid in the body, known as hyperuricemia, which causes buildup of uric acid crystals and inflammation, leading to tophaceous gout in people with chronic or undertreated disease.
Despite available therapies that aim to reduce uric acid levels below the target 6 mg/dL, a major treatment gap remains between first-line xanthine oxidase inhibitors (XOIs) and last-line uricase therapy. Currently, no suitable second-line options exist in the U.S. or E.U., leaving a critical unmet need for patients who fail to respond to first-line treatments.
Dotinurad's Clinical Profile and Regulatory Status
Dotinurad was invented by Fuji Yakuhin (search) and has obtained regulatory approval in Japan, China, Philippines and Thailand. The next-generation URAT1 (search) inhibitor is being developed as a second-line therapy aimed to reduce uric acid, gout flares and tophi, with best-in-class potential for both safety and efficacy supported by clinical data from multiple Asian markets where it is approved.
Crystalys Therapeutics (search), a clinical-stage biopharmaceutical company headquartered in San Diego, California, and co-founded by Catalys Pacific (search) and Novo Holdings (search), is dedicated to transforming the treatment of gout by delivering more effective options for people living with the condition.