Where Could Obefazimod Fit in UC Treatment, With Remo Panaccione, MD

Topline results from Part 2 of the phase 3 ABTECT maintenance trial showed obefazimod sustained clinical benefit through week 44 in patients with ulcerative colitis (UC) who had not initially responded to induction therapy, adding to positive Part 1 data released earlier this year.

With those results in hand, Remo Panaccione, MD, professor of medicine and director of the IBD Clinic at the University of Calgary, spoke with HCPLive about where obefazimod might fit into an increasingly crowded UC treatment landscape.

"You're absolutely right that it's becoming a crowded landscape," Panaccione said.

How Does Obefazimod's Mechanism Set It Apart?

Obefazimod is a once-daily oral small molecule with a mechanism of action unlike anything currently available in the clinic. Rather than broadly suppressing the immune system, it works by increasing expression of miR-124, a naturally occurring microRNA that helps bring the immune system back into balance. "It's not a true immunosuppressant like some of the therapies we have," Panaccione said.

In Part 1 of the ABTECT maintenance trial, both the 25 mg and 50 mg doses of obefazimod met the primary endpoint of clinical remission at week 44, with remission rates of approximately 51% compared with 10% with placebo. Endoscopic remission, a Mayo endoscopy score of 0 among patients who entered the trial with a score of 2 or 3, was achieved by 41.5% of patients on 25 mg and 47.7% of patients on 50 mg, versus 10% on placebo. Part 2 data, released in June, showed continued benefit among patients who had not initially responded to induction therapy, with no new safety signals through 44 weeks.

Could Obefazimod Work Across Multiple Lines of Therapy?

Panaccione said the combination of oral dosing, once-daily administration, and strong efficacy makes obefazimod attractive across a range of patient populations, not just one line of therapy. "That combination of oral, once daily, is attractive from a patient perspective," he said. "And if you combine that with the efficacy we just discussed, which, without a direct comparison, is some of the strongest efficacy we've seen, and no safety signal in an expanding, large safety database, I can see this being used across multiple different patient populations."

He described a dual role: as a strong first advanced therapy option for patients who need to start one, and as a viable option later in the treatment course given the refractory population studied in ABTECT. "This can easily be slotted as a first advanced therapy in patients who need to go onto an advanced therapy," Panaccione said. "But also, because of the patient population that was studied here, in particular the patients who are refractory to other advanced therapies and JAK inhibitors, it could also slot in as a second line and or a third line therapy."

Panaccione also pointed to an early durability signal from the phase 2 program, where patients who achieved a response tended to maintain it over time. He said that pattern could reflect the drug's efficacy, its non-immunogenic profile as an oral small molecule, or its underlying mechanism of restoring immune balance.

What Should Clinicians Watch For Ahead of FDA Review?

Abivax has said it plans to submit a new drug application (NDA) to the US Food and Drug Administration (FDA) in late fourth quarter 2026. Asked what clinicians should keep in mind as that submission approaches, Panaccione encouraged a close, independent read of the data once it's published rather than taking topline figures at face value.

He said clinicians should evaluate the published data against the phase 3 evidence that has already supported regulatory approvals for other UC therapies, paying particular attention to both absolute and placebo-adjusted efficacy numbers. "They should think about those absolute numbers and those placebo-adjusted numbers and what that's going to mean not only for their own practice, but for their patients," Panaccione said.

Editors' note: Panaccione has relevant disclosures with Abbott, AbbVie, Abivax, Alimentiv, Amgen, AstraZeneca, Boehringer Ingelheim, Bristol Myers Squibb, Eli Lilly, Ferring, Galapagos, Gilead Sciences, Janssen, Merck, Novartis, Pfizer, Takeda, and others.

References

1. Abivax announces landmark Phase 3 ABTECT maintenance trial results evaluating obefazimod in moderately to severely active ulcerative colitis. News release. Abivax. June 1, 2026. Accessed August 19, 2026. https://www.globenewswire.com/news-release/2026/06/01/3304711/0/en/abivax-announces-landmark-phase-3-abtect-maintenance-trial-results-evaluating-obefazimod-in-moderately-to-severely-active-ulcerative-colitis.html

2. Abivax reports positive ABTECT maintenance Part 2 results for obefazimod, demonstrating meaningful clinical benefit in refractory ulcerative colitis patients and strengthening the Phase 3 maintenance safety database. News release. Abivax. June 29, 2026. Accessed August 19, 2026. https://ir.abivax.com/news-releases/news-release-details/abivax-reports-positive-abtect-maintenance-part-2-results/