Abivax S.A. rose over 35% in pre-market trading, trading at $130.35/share. The rally was driven by the company's announcement of positive topline results from ABTECT Maintenance Part 2, a supplemental Phase 3 trial evaluating obefazimod in ulcerative colitis patients who did not respond to induction or relapsed during the main maintenance study.

Among induction non-responders, 50mg obefazimod achieved 37.2% clinical remission and 61.5% clinical response at Week 44. Among relapsed patients previously on placebo, re-treatment yielded clinical response and remission rates of 69.7% and 45.0%, respectively. Critically, no new safety signals emerged, with malignancy rates remaining consistent with background expectations.

The stock had previously plunged nearly 50% from approximately $130 to $70 after the 50mg group reported multiple cancer cases. This supplemental data confirming both efficacy and a clean safety profile has progressively resolved prior concerns, accelerating bullish sentiment and driving the stock to recover its earlier losses.