Arthrosi Therapeutics has raised $153 million to bankroll its bid to clout gout. The series E financing gives the biotech the financial firepower to deliver data from two phase 3 trials next year.
San Diego-based Arthrosi completed enrollment in a pair of phase 3 gout trials earlier this year. After wrapping up enrollment in the second study in August, the biotech sketched out a timeline that takes in two data drops in 2026 on the way to a filing for approval of pozdeutinurad. Two years after raising a $75 million series D round, Arthrosi now has the money to execute the next steps in its late-phase strategy.
Arthrosi is aiming to report its first pivotal data on pozdeutinurad in the second quarter of next year. The drug candidate is an inhibitor of URAT1, a transporter that has been a target for gout drugs going back to the approval of probenecid in 1951.
Probenecid and other early gout drugs hit multiple targets and caused a range of side effects. Seeking to avoid the adverse events, developers of subsequent waves of gout drugs tried to create more potent and specific URAT1 inhibitors. AstraZeneca acquired a URAT1 inhibitor in its $1.3 billion takeover of Ardea Biosciences in 2012 and won FDA approval for the drug in 2015. By 2018, the product, Zurampic, had landed on the scrap heap.
The commercial struggles of Zurampic, which carried a boxed warning, didn't deter others from trying to launch URAT1 inhibitors. A team behind Zurampic has reformed at Crystalys Therapeutics to advance dotinurad, a URAT1 inhibitor that is approved in Asian markets including Japan. And China’s Atom Therapeutic recently reported a phase 2b/3 win for its own URAT1 inhibitor, lingdolinurad.
Amid the continued interest in URAT1, a syndicate of investors has bet that Arthrosi can carve out a piece of the market. Prime Eight Capital led the series E round with support from CR Biotech, HighLight Capital, HM Venture Partners, ReliantTech and existing shareholders, according to Arthrosi's Oct. 8 release.