Abivax stock climbed more than 30% on Tuesday after the French biotech released additional data from its late-stage trial of obefazimod, its experimental ulcerative colitis treatment, showing that cancer cases in the study were consistent with background rates expected in that patient population.
That release came about four weeks after Abivax stock fell as much as 40% following an earlier data readout that identified seven distinct cancer diagnoses across the study population — each assessed by investigators as bearing no likely connection to the drug, though the disclosure was enough to unsettle markets.
What Abivax published constituted the second, supplemental portion of a Phase 3 study designed to track outcomes over 44 weeks in ulcerative colitis patients during a maintenance period. Beyond the safety picture, the efficacy data showed that extended dosing at 50 mg produced clinical remission in 37.2% of patients whose disease had not responded to the initial induction phase, according to Sharecast . For patients who experienced relapse within the maintenance window, a dose escalation from 25 mg to 50 mg brought about clinical remission recovery in 45.5% of that group.
"The expanded cumulative safety data further strengthens our confidence in the long-term safety profile of obefazimod and reinforces the favorable benefit-risk profile for our program as we prepare for our planned new drug application submission later this year," CEO Marc de Garidel said in a statement.
Abivax said it remains on track to submit an NDA to the U.S. Food and Drug Administration in the fourth quarter of 2026, the company said.
Analyst reactions were broadly positive. Stifel kept its buy rating and €115 price target, calling the safety profile reassuring, while Oddo BHF, which held its €120 target, told clients the latest analyses offered substantially more comfort on cancer risk than the figures released earlier in the month. Concerns about a potential link between obefazimod and tumor development should now be resolved, Piper Sandler argued.
Jefferies struck a more measured tone, acknowledging the data were supportive but flagging that retail and generalist shareholders could struggle to look past the malignancy signal, particularly in light of the company's capital requirements and a near-term pipeline with few obvious inflection points outside a potential acquisition, according to CNBC .
Abivax is also testing obefazimod as a treatment for Crohn's disease, with trial results expected around mid-2027. Wall Street analysts see obefazimod as a potential leader in its field, and there has been a lot of speculation about a possible buyout by a major pharmaceutical company.
