Safety concerns over cancer cases in a high-dose cohort overshadow strong Phase 3 efficacy data for obefazimod.
Abivax SA shares collapsed up to 40% after releasing Phase 3 data for its ulcerative colitis drug, obefazimod. The trial showed strong efficacy, with clinical remission rates of 50.8% and 51.3% for 25 mg and 50 mg doses, respectively, compared to 10.4% for placebo.
Investor confidence faltered after scattered cancer cases were reported exclusively in the high-dose 50 mg cohort. The safety concerns triggered an immediate analyst downgrade, despite the drug’s potential to challenge established treatments.
The market reaction underscored sensitivity to safety risks in late-stage trials, particularly for drugs targeting chronic conditions.