Abivax shares surged dramatically after Phase III results for obefazimod, an oral ulcerative colitis drug, exceeded expectations, catalyzing a heavily oversubscribed U.S. offering initially set at $400 million but expanded to $747.5 million. CEO Marc de Garidel projected blockbuster potential pending maintenance trial data. Funds raised will accelerate obefazimod’s development for ulcerative colitis and Crohn’s disease. The stock’s meteoric rise reflects investor enthusiasm for the novel anti-inflammatory agent targeting immune modulation in difficult-to-treat inflammatory bowel disease.