ABIVAX (ABVX) Study result summary

Study design and patient population

• ABTECT Maintenance Part 2 included highly refractory ulcerative colitis patients, focusing on induction non-responders and Part 1 relapsers, all treated with obefazimod, primarily at 50 mg.

• Over 55% of Part 2 patients had failed at least one advanced therapy, with a high proportion of JAK inhibitor failures and higher baseline inflammatory burden than Part 1.

• No placebo arm was included in Part 2; all patients received active treatment.

• Part 2 served as a supplemental dataset, expanding the cumulative safety and efficacy data for obefazimod.

Efficacy results

• 37.2% of 50 mg induction non-responders achieved clinical remission and 34.5% achieved endoscopic remission at Week 44.

• Dose escalation from 25 mg to 50 mg restored disease control in 45.5% of relapsed patients, with clinical response rates up to 69.7%.

• Induction non-responders treated with 50 mg showed clinical response (61.5%), endoscopic improvement (48.0%), and HEMI (44.6%) at Week 44.

• Endoscopic remission rates in induction non-responders were as high or higher than those reported for other approved therapies.

• Efficacy was durable and clinically meaningful in a highly refractory population, with high completion rates up to 44 weeks.

Safety findings

• Over 1,700 patient-years of exposure were accumulated across phase II and III, with >100 patients treated for more than 5 years.

• Malignancy and NMSC rates were within or below expected background rates, with all NMSC cases in Part 2 occurring in patients with established risk factors.

• No new or unexpected safety patterns were identified; serious infections and opportunistic infections were infrequent.

• Exposure-adjusted incidence rates for malignancies (excluding NMSC) and NMSC in all active arms remained within published UC reference ranges.

• No evidence of increased skin-related toxicity or cardiac fibrosis was observed.