** U.S.-listed shares of French biotech firm Abivax ABVX.PA, ABVX.O jump 550% to $65.13

** Stock set for its best day in record, if gains hold

** Late on Tuesday, co said its experimental drug obefazimod met the main goal of achieving clinical remission in two late-stage trials for treating moderate to severely active ulcerative colitis, a type of inflammatory bowel disease

** The 50 mg daily dose of obefazimod led to significantly higher clinical remission rates than placebo after 8 weeks in both trials, co said

** Ulcerative colitis is a chronic inflammatory disease that causes swelling and ulcers in the lining of the colon and rectum

** The trials included patients who had not responded to previous advanced treatments

** Abivax plans to file for FDA approval in late 2026 following expected Q2 2026 maintenance trial results for the drug

** Including session's moves, stock up 795% YTD

(Reporting by Kamal Choudhury in Bengaluru)

((Kamal.Choudhury@thomsonreuters.com;))