Both doses of once-daily pozdeutinurad (AR882) met the primary efficacy endpoint of sUA reduction at month 6 vs placebo

Pozdeutinurad was overall well tolerated, and the safety profile was consistent with previous studies

Sobi® (STO: SOBI) today announced positive topline results from the pivotal Phase 3 REDUCE 2 study (NCT06439602) evaluating pozdeutinurad (AR882), an investigational next-generation once-daily oral selective URAT1 inhibitor, in adults with gout including those with uncontrolled gout (also referred to as progressive gout) and inadequately controlled by existing therapies.

Both doses of pozdeutinurad met the primary efficacy endpoint, defined as the proportion of patients achieving a serum uric acid (sUA) level <6 mg/dL at month 6 (75 mg: 69.2% vs 8.1%; p<0.0001; 50 mg: 56.6% vs 8.1%; p<0.0001). The safety profile was consistent with previous studies. Detailed results are expected to be presented at a forthcoming scientific congress in Q4.

"We are very encouraged by these results and their implications for patients whose gout remains inadequately controlled," said Lydia Abad-Franch, MD, Head of R&D and Medical Affairs and Chief Medical Officer at Sobi. "These findings, including sustained urate lowering and a favourable efficacy and tolerability profile, support the potential of pozdeutinurad to address a significant unmet need and provide a strong foundation for regulatory submissions."

Pozdeutinurad was added to Sobi's global development portfolio in February 2026 following its acquisition of Arthrosi, Inc., a biotechnology company focused on developing treatments for gout, and further enhances Sobi's presence in this area. Pozdeutinurad is being investigated in two global Phase 3 studies, REDUCE 1 and REDUCE 2 which are 12-month, randomised, double-blind, placebo-controlled trials designed to evaluate pozdeutinurad in patients with gout, including those with tophaceous gout. REDUCE 1 and REDUCE 2 enrolled more than 800 patients each. REDUCE 1 is fully enrolled, and data are expected in the second half of 2026.

About the REDUCE 2 study

REDUCE 2 was a pivotal Phase 3, twelve-month, randomised, double-blind, placebo-controlled study. The study included 811 patients globally with a majority being inadequate responders to urate lowering therapies (ULTs). Patients were randomised into one of three groups either receiving pozdeutinurad 50mg, pozdeutinurad 75mg or placebo. The primary efficacy endpoint was proportion of participants whose sUA level is < 6.0 mg/dL at month 6. Secondary endpoints included a reduction in flares and tophi over time, and safety.

About gout

Gout is the most common form of inflammatory arthritis and is caused by elevated levels of uric acid that accumulate in joints and other tissues, leading to painful flares. If left untreated, gout can lead to serious consequences such as frequent flares and persistent uric acid build-up can result in chronic joint damage, reduced mobility and the formation of tophi (hard deposits under the skin).

While many patients with gout are treated in first line with urate lowering therapy some are sub-optimally treated or do not respond to first line therapies and the disease progresses to uncontrolled gout which is associated with a higher risk of comorbidities such as kidney disease and cardiovascular complications. Despite available treatments, many patients struggle to achieve target uric acid levels, underscoring the need for additional therapeutic options to prevent long-term disability and improve quality of life.

About pozdeutinurad

Pozdeutinurad (AR882) is an investigational URAT1 inhibitor being developed for the treatment of patients with gout, including those with uncontrolled gout and tophaceous gout. Phase 2 studies demonstrated compelling efficacy with a sustained reduction of serum uric acid, dissolution of tophi and a well-tolerated safety profile. It is being evaluated in two Phase 3 studies, REDUCE 1 and REDUCE 2, two twelve-month, randomised, double-blind, placebo-controlled studies to assess pozdeutinurad's ability to reduce sUA in gout patients including those with uncontrolled gout and tophaceous disease.

Sobi®

Sobi is a global biopharma company unlocking the potential of breakthrough innovations, transforming everyday life for people living with rare diseases. Sobi has approximately 2 000 employees across Europe, North America, the Middle East, Asia and Australia. In 2025, revenue amounted to SEK 28 billion. Sobi's share (STO:SOBI) is listed on Nasdaq Stockholm. More about Sobi at sobi.com and LinkedIn.

Contacts

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This information is information that Sobi is obliged to make public pursuant to the EU Market Abuse Regulation and/or the Swedish Securities Markets Act. The information was submitted for publication, through the agency of the contact person set out below, on 21 May 2026 at 22:30 CEST.

Gerard Tobin

Head of Investor Relations