Abivax Shares Jump 36% on Positive Ulcerative Colitis Drug Data

Paris-based biotechnology company Abivax, which develops treatments for chronic inflammatory diseases, saw its shares jump 36% on Tuesday after releasing new data on its lead drug candidate, obefazimod.

The latest results from the maintenance phase of its Phase 3 ABTECT trial showed the experimental oral treatment provided “clinically meaningful improvements” for adults with moderate to severe ulcerative colitis, including patients whose disease had previously failed to respond to treatment.

After 44 weeks, 37.2% of patients who had not responded during the initial treatment phase achieved clinical remission, meaning their symptoms had largely disappeared, while 34.5% showed healing of the bowel lining.

Among patients whose disease returned after initially improving, increasing the dose to 50 mg helped 45.5% regain remission, according to the company.

The update comes just weeks after Abivax shares plunged 44% on 2 June, following the release of Phase 3 safety data from the ABTECT maintenance trial.

The company also said the current, expanded safety analysis found cancer rates remained within the range typically seen in people with ulcerative colitis.

According to combined safety data from the Phase 2 and Phase 3 programmes, representing the equivalent of 1,704 years of patient treatment, the rate of cancers excluding non-melanoma skin cancer was 0.35 and 0.64 cases per 100 patient-years in the combined treatment and 50 mg groups, respectively. For non-melanoma skin cancer, the rates were 0.59 and 0.64 cases per 100 patient-years.

The company stated that the analysis did not identify a new or unexpected safety signal.

“The expanded cumulative safety data further strengthens our confidence in the long-term safety profile of obefazimod and reinforces the favourable benefit-risk profile for our programme as we prepare for our planned NDA submission later this year," Chief Executive Marc de Garidel said in a statement.

Abivax said it remains on track to submit a New Drug Application for obefazimod to the US Food and Drug Administration in the fourth quarter of 2026.

The company is also evaluating obefazimod as a treatment for Crohn's disease, another form of inflammatory bowel disease, which could broaden its commercial opportunity beyond ulcerative colitis. Results from a mid-stage Phase 2 trial are expected in mid-2027.

Abivax shares were trading up 36% at €113.30 in Paris on Tuesday afternoon.