For $950 million upfront, Sobi will gain ownership to pozdeutinurad, an oral URAT1 inhibitor that performed well in Phase II studies.
Sobi is taking over California-based Arthrosi Therapeutics in a move to join the growing group of biopharma companies playing in the gout arena.
The Swedish pharma is fronting $950 million in cash and has pledged up to $550 million in clinical, regulatory and sales milestones. Sobi and Arthrosi expect to close the transaction in the first half of 2026, pending antitrust clearances and other customary closing conditions.
Sobi will fund the purchase mainly through debt, the company said in a Saturday news release, but expects the Arthrosi acquisition to be “highly accretive” to its mid- and long-term growth.
The centerpiece of Saturday’s deal is pozdeutinurad, a next-generation oral inhibitor of the URAT1 protein, a molecule that plays a major role in uric acid reabsorption. This mechanism, according to Arthrosi’s website, boosts the excretion of uric acid by the kidneys, helping keep concentrations within the normal range.
Mid-stage data showed that a 50 mg dose of pozdeutinurad lowered serum uric acid levels to below 5 mg/dL in 93% of patients, as opposed to 11% in comparators on allopurinol and 33% in those treated with febuxostat. Allopurinol and febuxostat are FDA-approved drugs for uric acid control. A 75 mg dose of pozdeutinurad showed better efficacy, suppressing uric acid to below 4 mg/dL in 88% of treated patients, according to Arthrosi’s website.
Pozdeutinurad is currently in two Phase III studies, one for progressive and another for tophaceous gout. Data from these trials are expected next year, Sobi said on Saturday.
“Pozdeutinurad has the potential to become the therapy of choice for patients who have progressive gout with persistent and unresolved symptoms,” Sobi CEO Guido Oelkers said in a prepared statement.
The Sobi takeover comes just two months after Arthrosi closed a series E round in early October, bringing in $153 million in proceeds. Much of the money was earmarked to fund pozdeutinurad’s late-stage development.
Elsewhere in the gout arena, Crystalys Therapeutics, a Novo Nordisk-backed startup, launched in late September with $205 million in series A funds. Crystalis is testing dotinurad, which like pozdeutinurad is an oral URAT1 blocker, in two Phase III trials for gout. The biotech dosed its first patients in October.
Also in September, Atom Therapeutics declared Phase IIb/III victory for its URAT1 blocker lingdolinurad, which showed “outstanding urate lowering effects,” the Chinese biotech claimed at the time.
