Biotech takeover target Abivax sinks over 43% as cancer cases cloud trial data for bowel disease drug Shares of Abivax dropped significantly after reporting fresh data on its ulcerative colitis drug, obefazimod, which showed clinically meaningful efficacy but also cancer cases among patients. This has led analysts to express concerns about a potential overhang, even though investigators deemed the cases unrelated to treatment, and has raised questions about the company’s potential takeover. Despite these concerns, Abivax remains confident in the drug’s potential and plans to submit it for FDA approval, while potential buyers are expected to await further data.

• Abivax shares fell 43.6% following new data on its ulcerative colitis drug, obefazimod.
• The drug met efficacy endpoints but showed cancer cases among patients, particularly at the higher dose.
• Investigative assessments suggest the cancer cases are unrelated to the treatment.
• Analysts expressed concerns about the “cancer signal” creating an overhang, leading to a downgrade from Buy to Hold.
• Despite the setback, Abivax’s drug is considered a potential best-in-class treatment for ulcerative colitis and Crohn’s disease.
• The company is considered a takeover target, with CEO Marc de Garidel confident in securing better terms for partnerships after future data readouts.
• Abivax plans to submit obefazimod for FDA approval in the fourth quarter, with a potential launch in 2027.
• Potential buyers are likely to wait for the full data set, expected in October, before making a move.