Sobi, a pharmaceutical company based in Sweden, has announced the acquisition of Arthrosi Therapeutics, a California-based firm focused on treatments for gout. The deal is valued at up to $1.5 billion, with Sobi paying $950 million in cash and an additional $550 million tied to clinical, regulatory, and sales milestones. Both companies expect the transaction to close in the first half of 2026, pending antitrust approval and other standard conditions.
According to Sobi’s statement, most of the purchase will be financed through debt. The company anticipates that acquiring Arthrosi will contribute significantly to its mid- and long-term growth.
The main asset in this acquisition is pozdeutinurad, an oral inhibitor targeting the URAT1 protein. This protein plays a significant role in reabsorbing uric acid in the kidneys. By inhibiting URAT1, pozdeutinurad increases uric acid excretion and helps maintain normal levels.
Mid-stage trial results showed that a 50 mg dose of pozdeutinurad reduced serum uric acid below 5 mg/dL in 93% of patients. In comparison, only 11% of those on allopurinol and 33% on febuxostat achieved similar results. Allopurinol and febuxostat are currently approved drugs for controlling uric acid levels. A higher dose of pozdeutinurad (75 mg) further lowered uric acid below 4 mg/dL in 88% of treated patients.
Pozdeutinurad is now being studied in two Phase III trials: one for progressive gout and another for tophaceous gout. Data from these studies are expected next year.
“Pozdeutinurad has the potential to become the therapy of choice for patients who have progressive gout with persistent and unresolved symptoms,” said Sobi CEO Guido Oelkers.
The acquisition follows Arthrosi’s recent Series E funding round completed in October, which raised $153 million primarily for advancing pozdeutinurad’s late-stage development.
Other companies are also pursuing treatments targeting URAT1 for gout. Crystalys Therapeutics, supported by Novo Nordisk, launched recently with $205 million from a Series A round and is testing dotinurad—another oral URAT1 blocker—in Phase III trials. Atom Therapeutics reported positive results from its own URAT1 blocker lingdolinurad after Phase IIb/III trials earlier this year.
