STOCKHOLM, December 13, 2025 – Swedish biopharmaceutical company Sobi® (STO: SOBI) has announced a definitive agreement to acquire Arthrosi Therapeutics, Inc., a U.S.-based late-stage biotechnology company developing innovative therapies for gout. The strategic acquisition is valued at up to $1.5 billion and marks a major expansion of Sobi’s presence in inflammatory and rare disease treatment, specifically within the gout therapeutic market.
Under the terms of the deal, Sobi will pay $950 million (approximately SEK 9.1 billion) in cash upfront, with an additional $550 million (SEK 5.3 billion) contingent on achieving key clinical, regulatory, and commercial milestones. The acquisition, which is subject to customary closing conditions, is expected to complete in the first half of 2026.
Expanding Sobi’s Leadership in Gout Management
The acquisition adds pozdeutinurad (AR882) to Sobi’s growing gout franchise — an investigational, next-generation, once-daily oral URAT1 inhibitor currently being evaluated in two fully enrolled global Phase 3 clinical trials. The trials aim to assess the drug’s efficacy in managing progressive and tophaceous gout, conditions characterized by persistent symptoms despite standard first-line therapy.
With Phase 3 data expected to read out in 2026, pozdeutinurad could potentially emerge as a best-in-class therapy for patients who do not respond adequately to existing treatments. The drug is designed to lower serum uric acid levels more effectively and with improved safety and tolerability compared to older urate-lowering therapies.
Sobi’s President and CEO, Guido Oelkers, emphasized that the acquisition underscores the company’s long-term vision to transform treatment standards for gout patients worldwide.
“The acquisition of Arthrosi allows us to expand our gout pipeline with a highly differentiated new asset,” said Oelkers. “Pozdeutinurad has the potential to become the therapy of choice for patients who continue to experience unresolved gout symptoms despite first-line treatments. This product could materially accelerate our growth through the mid-2030s and beyond. We are delighted to welcome the Arthrosi team and look forward to bringing this therapy to patients as soon as possible.”
Strategic Growth Through Innovation
Sobi has positioned itself as a leader in the development of targeted therapies for rare and inflammatory diseases. The acquisition of Arthrosi complements Sobi’s existing portfolio and provides a strategic boost to its innovation pipeline, further solidifying its standing in the immunology and rheumatology sectors.
By integrating Arthrosi’s late-stage asset, Sobi gains access to a promising candidate that could address a major unmet medical need among patients with chronic, treatment-resistant gout.
Arthrosi’s Perspective: A Shared Mission to Transform Gout Care
Dr. Litain Yeh, Founder and CEO of Arthrosi Therapeutics, expressed enthusiasm about joining forces with Sobi to accelerate the global reach of pozdeutinurad.
“We are thrilled to join forces with Sobi and look forward to a seamless transition as they advance pozdeutinurad toward pivotal data and potential regulatory filings,” said Dr. Yeh. “Sobi’s global expertise in commercialization will help bring pozdeutinurad’s potentially transformative benefits to people living with gout around the world.”
Financial and Transaction Details
Sobi intends to fund the $950 million upfront payment primarily through existing credit facilities and a new debt facility arranged with Handelsbanken and Danske Bank. The transaction is expected to be highly accretive to Sobi’s mid- to long-term growth and profit margins, aligning with the company’s goal of sustained value creation through strategic innovation and portfolio diversification.
Barclays Bank PLC is serving as financial advisor to Sobi, while McDermott, Will & Schulte is acting as legal counsel for the transaction.
Strengthening Sobi’s Market Position
The acquisition not only strengthens Sobi’s competitive position in gout management but also aligns with its broader mission to improve the lives of people with rare and chronic diseases. By integrating advanced science with patient-focused innovation, Sobi aims to accelerate the delivery of next-generation therapies that provide meaningful, measurable benefits.
Pozdeutinurad’s once-daily oral formulation represents a significant advancement over traditional gout medications, many of which require complex dosing or present limitations in long-term tolerability. If approved, the therapy could redefine standard-of-care for millions of patients worldwide living with uncontrolled or progressive gout.