Abivax Shares Soar 475% on Positive Phase 3 Ulcerative Colitis Trial Results

Abivax SA (NASDAQ:ABVX) shares surged in post-market trading Tuesday after the French biotech firm announced successful Phase 3 trial results for its ulcerative colitis treatment, obefazimod. The oral therapy met its primary endpoint in two large late-stage studies, demonstrating a significant improvement over placebo in achieving clinical remission after just eight weeks.

Nearly half of the patients enrolled had previously failed to respond to other advanced treatments, highlighting obefazimod’s potential as a promising new option for hard-to-treat cases. The safety profile remained consistent with earlier studies, with no new adverse signals reported.

Following the announcement, Abivax’s U.S.-listed stock skyrocketed 475%, closing at $57.15 as of 20:01 ET. The dramatic rally reflects investor optimism over the drug’s potential regulatory path and commercial success.

Abivax intends to submit applications for regulatory approval in the U.S. and Europe by 2026, pending the results of long-term maintenance studies expected that same year. If approved, obefazimod could provide a new oral alternative to current ulcerative colitis therapies, many of which require injections or infusions.

The breakthrough positions Abivax as a rising biotech contender, particularly in the competitive gastrointestinal disease market. The company’s progress is likely to attract increased attention from institutional investors and potential pharmaceutical partners.

With inflammatory bowel disease affecting millions globally, the demand for safer, more convenient treatment options remains high. Abivax’s clinical success could significantly reshape the treatment landscape for ulcerative colitis if future results remain positive.

This development marks a major milestone for Abivax and reinforces confidence in its clinical pipeline. Investors will now closely monitor the 2026 maintenance data and regulatory decisions.