Arthrosi Therapeutics Surpasses 50% Patient Enrollment in Replicate Pivotal Phase 3 REDUCE 1 Trial of Pozdeutinurad (AR882) in Patients with Gout, Including Those with Tophaceous Gout

— REDUCE 1 enrollment is well ahead of schedule; completion of enrollment expected in 2H 2025 —

— REDUCE 1 is a study running in parallel with REDUCE 2 to evaluate pozdeutinurad's efficacy in lowering serum urate (sUA) levels and resolution of target tophi in gout patients —

SAN DIEGO, July 1, 2025 /PRNewswire/ -- Arthrosi Therapeutics, Inc., a late-stage biotechnology company developing a potentially best-in-class, highly potent and selective next generation URAT1 inhibitor to reduce serum urate (sUA) levels, flares, and dissolve tophi in gout and tophaceous gout patients, today announced that it has enrolled more than 50% of patients in the Company's second pivotal Phase 3 clinical trial (REDUCE 1) evaluating pozdeutinurad (formerly known as AR882) for the reduction of sUA and tophi in gout and tophaceous gout patients.

"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. "Similar to the momentum observed in our fully-enrolled REDUCE 2 study, patient enrollment in REDUCE 1 is well ahead of schedule, and we remain on track to complete enrollment in the second half of this year. We are working tirelessly to advance pozdeutinurad for gout patients in need and look forward to sharing a comprehensive data update in Q2 2026."

REDUCE 1 is the Company's second pivotal twelve-month, randomized, double-blind, placebo-controlled study evaluating pozdeutinurad. The study is expected to enroll approximately 750 gout patients including patients with tophi. Patients will be randomized into one of three groups either receiving pozdeutinurad 50 mg, pozdeutinurad 75mg or placebo. The primary endpoint is reduction of sUA by month six. Secondary endpoints include tophi and flare reduction. The trial is expected to be completed by the end of 2026.

For more information about REDUCE 1, please visit https://clinicaltrials.gov/ (identifier NCT06846515).

About Arthrosi:
Arthrosi Therapeutics, Inc., headquartered in San Diego, CA, is focused on developing pozdeutinurad (AR882), a potentially best-in-class, highly potent and selective next generation URAT1 inhibitor to reduce serum urate levels, flares and tophi in patients with gout. Pozdeutinurad has demonstrated encouraging efficacy and safety compared to SOC in Phase 2 studies as well as impressive results in achieving complete resolution of tophi in a Phase 2b study. Arthrosi is currently advancing pozdeutinurad in a pivotal Phase 3 program.

About Gout:
In the U.S., an estimated 13 million individuals are diagnosed with gout, ~2 million of which have tophaceous gout. Gout is a form of inflammatory arthritis that can significantly diminish mobility, functionality, and overall quality of life. Gout emerges from the crystallization of uric acid within the joints and soft tissue, instigating painful flare-ups and chronic symptoms. The kidneys play a pivotal role in the process, as they are responsible for filtering out and excreting uric acid from the body. In over 90% of gout patients, underexcretion of uric acid results in the imbalanced and elevated sUA levels that can lead to the deposition of uric acid crystals. It's essential to monitor and manage sUA levels as part of comprehensive gout treatment and prevention strategies.

Media Contact:
Shunqi Yan, PhD
Founder & Chief Operating Officer
shunqi.yan@arthrosi.com

Investor Contact:
Precision AQ
Alex Lobo
212-698-8802
alex.lobo@precisionaq.com 

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SOURCE Arthrosi Therapeutics