Arthrosi Secures $153 Million in Series E Financing to Complete Pivotal Development of Pozdeutinurad for the Treatment of Gout and Tophaceous Gout

• Enrollment complete in the replicate REDUCE 1 and REDUCE 2 Phase 3 studies with pivotal data expected in Q2 2026

SAN DIEGO, Oct. 8, 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 the closing of its $153 million Series E financing led by Prime Eight Capital Limited and with participation from CR Biotech,HighLight Capital, HM Venture Partners, , ReliantTech Limited and existing shareholders.

Arthrosi plans to use the proceeds from this financing to complete the clinical development of its lead program, pozdeutinurad (AR882), through its replicate Phase 3 REDUCE 1 and REDUCE 2 studies evaluating pozdeutinurad for the treatment of gout and tophaceous gout. These twelve-month, randomized, double-blind, placebo-controlled studies are designed to assess pozdeutinurad's ability to reduce sUA in patients with gout and tophaceous gout. Secondary endpoints include reduction in flares and tophi over time. Both Phase 3 trials are now fully enrolled, and the Company expects to report pivotal data in Q2 2026.

"We are delighted to have the continued support of an experienced and deeply committed group of investors," said Litain Yeh, Ph.D., Founder and CEO of Arthrosi Therapeutics. "Arthrosi continues to make rapid progress on our mission to transform the treatment landscape for gout and tophaceous gout, an area with pressing unmet need. The commitment from both new and existing investors provides further validation for pozdeutinurad and the robust clinical data package we have generated to date. With their support, we look forward to advancing our pivotal Phase 3 program as we work to deliver pozdeutinurad's potentially transformative benefits to patients as soon as possible."

"We're excited to partner with Arthrosi as they advance pozdeutinurad through late-stage development," said Prime Eight Capital. "The company's strong management team with a focus on execution gives us confidence in Arthrosi's ability to deliver a potentially best-in-class treatment for gout. We share their vision to make pozdeutinurad accessible to patients globally and are proud to support a team with the expertise, discipline, and urgency to make that vision a reality."

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.

Arthrosi Contact:
Shunqi Yan, PhD
Founder & Chief Operating Officer
[email protected]

Precision AQ Contact:
Alex Lobo
212-698-8802
[email protected]

SOURCE Arthrosi Therapeutics