Arthrosi Therapeutics has achieved a significant enrollment milestone in its pivotal Phase 3 clinical trial for pozdeutinurad, a next-generation URAT1 inhibitor being developed for gout treatment. The San Diego-based biotechnology company announced that it has enrolled more than 50% of patients in its REDUCE 1 study, with enrollment proceeding well ahead of schedule since the first patient was enrolled in March 2025.
Accelerated Trial Progress
"We are excited by the rapid enrollment in the REDUCE 1 study since enrolling our first patient in March 2025, reflecting the enthusiasm from investigators and patients for a potentially transformative treatment option for gout and tophaceous gout," said Dr. Robert T. Keenan, MD, MPH, Chief Medical Officer at Arthrosi Therapeutics. The company expects to complete enrollment in the second half of 2025, maintaining the momentum observed in its fully-enrolled REDUCE 2 study.
Study Design and Endpoints
REDUCE 1 represents Arthrosi's second pivotal twelve-month, randomized, double-blind, placebo-controlled study evaluating pozdeutinurad. The trial is designed to enroll approximately 750 gout patients, including those with tophaceous gout. Participants are randomized into three treatment groups: pozdeutinurad 50 mg, pozdeutinurad 75 mg, or placebo.
The study's primary endpoint focuses on reduction of serum urate (sUA) levels by month six, while secondary endpoints include tophi and flare reduction. The trial runs in parallel with REDUCE 2 and is expected to be completed by the end of 2026, with comprehensive data updates anticipated in Q2 2026.
Addressing Significant Unmet Medical Need
Gout represents a substantial healthcare burden in the United States, with an estimated 13 million individuals diagnosed with the condition, approximately 2 million of whom have tophaceous gout. The disease is a form of inflammatory arthritis that can significantly diminish mobility, functionality, and overall quality of life through the crystallization of uric acid within joints and soft tissue, causing painful flare-ups and chronic symptoms.
In over 90% of gout patients, underexcretion of uric acid by the kidneys results in imbalanced and elevated sUA levels that can lead to the deposition of uric acid crystals. This mechanism underscores the importance of monitoring and managing sUA levels as part of comprehensive gout treatment strategies.
Drug Development Profile
Pozdeutinurad, formerly known as AR882, is positioned as a potentially best-in-class, highly potent and selective next-generation URAT1 inhibitor designed to reduce serum urate levels, flares, and dissolve tophi in gout and tophaceous gout patients. The compound has demonstrated encouraging efficacy and safety compared to standard of care in Phase 2 studies, with particularly impressive results in achieving complete resolution of tophi in a Phase 2b study.
The rapid enrollment progress in both REDUCE 1 and the fully-enrolled REDUCE 2 study suggests strong clinical interest in this therapeutic approach for gout management, potentially addressing current treatment limitations in this patient population.
