Abivax SA announced operating highlights and ongoing clinical trials: ABTECT Obefazimod Phase 3 Program in UC: ABTECT is a randomized, double-blinded placebo-controlled trial evaluating the efficacy and safety of 50mg and 25mg doses of obefazimod administered once daily (QD) compared to placebo. In patients with moderately to severely active UC, the trial is enrolling 1,200 subjects across 36 countries at 600 trial sites and consists of an 8-week induction trial followed by a 44-week maintenance trial (for a total of 52 weeks of treatment). Anticipated milestones: Early First Quarter 2025: Anticipated enrollment completion of ABTECT program.

Early Second Quarter 2025: Expected top-line induction data read-out after eight weeks of treatment. First Quarter 2026: Planned top-line maintenance results after one year of treatment. With the milestone of 600 active trial sites in 36 countries achieved recently, and with close to 50% of patients currently enrolled, the obefazimod Phase 3 ABTECT program investigating efficacy and safety in adults with moderately to severely active UC is actively recruiting in all regions with an accelerated pace and is expected to reach full enrollment in early First Quarter 2025, with top-line results anticipated in early Second Quarter 2025.

Based on these timelines, assuming favorable results from the ABTECT trial program, the Company anticipates being in position to submit an NDA to the FDA in late H1 2026, seeking approval of obefazimod for the treatment of moderately to severely active UC. Obefazimod 25 mg long-term extension trial in UC: The obefazimod 25mg long-term extension trial is an open-label trial evaluating the long-term safety and efficacy of 25mg of obefazimod given once a day (QD) in subjects who have been previously enrolled in the Phase 2a and Phase 2b trials who were previously treated with 50mg of obefazimod (OLE and maintenance trials) and who are willing to continue their treatment. Anticipated milestone: Third Quarter 2024: Anticipated trial data read-out after one and two years of continued treatment with a reduced dose of obefazimod at 25 mg.

In an interim analysis as of July 31, 2023, of the 71 eligible patients, 63 completed their 48-week visit, 84% (53 of 63 patients) achieved disease control defined as stable or improved Modified Mayo Score on 25mg once-daily obefazimod. No new safety signals were detected in UC patients treated up to five years with oral, once daily obefazimod. Planned clinical trials: ENHANCE-CD: Obefazimod Phase 2b trial in Crohn?s disease (CD): ENHANCE-CD is a Phase 2b, multicenter, double-blind, placebo-controlled trial that will evaluate the efficacy, safety, pharmacokinetics, and pharmacodynamics of obefazimod in subjects with moderately to severely active CD.

The trial design consists of a 12-week induction period and a subsequent 40-week maintenance period. Anticipated milestones: September 2024: ENHANCE-CD planned start of patient enrollment. 2H 2026: ENHANCE-CD planned 12-week induction data read-out.

In alignment with FDA feedback on the Company?s initial Phase 2a IND application submission early 2024, the CD trial design was adapted to be a dose-ranging Phase 2b clinical trial. These adjustments to the obefazimod CD clinical program are not expected to have an impact on the overall program budget and projected supplemental New Drug Application (sNDA) submission timeline. R&D progress: Anticipated milestones: 2H 2024: Disclosure of preclinical data of obefazimod combination therapy for the treatment of moderately to severely active UC.

2H 2024: Selection of first obefazimod follow-on drug candidate from Abivax?s miR-124 library. Obefazimod in combination therapy: As previously announced, based on its early clinical profile, the formal process evaluating combination therapy of oral and injectable candidates with obefazimod in UC began in January 2024. Over the past six months, the Company has initiated the preclinical evaluation of combination therapies in mouse models.

The Company has generated exciting preliminary data that will be submitted for presentation at an upcoming scientific congress. Additional preclinical combination studies are ongoing. Obefazimod follow-on candidate selection from miR-124 library: R&D work on potential follow-on drug candidates to be selected from Abivax?s compound library is ongoing.

Selection of the first follow-on drug candidate is expected before the end of 2024 to further strengthen the Abivax pipeline.