Remo Panaccione, MD, FRCPC

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.

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

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.

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

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/

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Obefazimod could work as first, second, or third line therapy in ulcerative colitis ahead of a planned FDA submission this year.

Part 2 of the phase 3 ABTECT maintenance trial found that obefazimod sustained clinical remission through week 44 in

patients, including those who had not initially responded to induction therapy. The results build on positive Part 1 data and add to a growing safety database ahead of the company's planned 

"These results that we'll probably be talking about today are really building upon very impressive induction data, where we saw placebo-adjusted treatment differences for the primary endpoint of clinical remission, which was quite substantial," Remo Panaccione, MD, professor of medicine and director of the IBD Clinic at the University of Calgary, said in an interview with HCPLive.

ABTECT Maintenance Data Show Durable Remission in UC, With Remo Panaccione, MD

How Large Was the ABTECT Maintenance Population?

Panaccione noted the onset of benefit was rapid, "with separation from placebo as early as one week for symptomatic response and week two for symptomatic remission." Part 1 of the maintenance study enrolled 580 patients who had responded to induction and entered the randomized, placebo-controlled maintenance phase, while Part 2 added 633 patients who had either not responded during induction or lost response during maintenance.

"This study also included a substantial portion of patients who were difficult to treat," Panaccione said. "In particular, it enrolled the largest cohort of patients with an inadequate response to a JAK inhibitor that we've ever studied in phase three clinical trials." He noted JAK inhibitor exposure typically signals later-line therapy, where patients tend to respond less robustly than treatment-naive patients or those exposed only to monoclonal antibodies.

Both the 25 mg and 50 mg doses met the primary endpoint of clinical remission at week 44, with remission rates around 51% compared to 10% with placebo. "This 40% difference, which is the largest placebo-adjusted difference that we've seen in a phase three trial, part of that may have been due to the fact that the placebo rate was quite low, and that speaks usually to the difficult-to-treat patient population," Panaccione said. Among initial non-responders continued on 50 mg, approximately 37% achieved remission and >60% achieved response; among those who relapsed on 25 mg and were escalated to 50 mg, remission was recaptured in approximately 56%.

What Did Endoscopic Remission Rates Show?

For Panaccione, the endoscopic data carried particular weight. "To get into the trial, the patients needed a Mayo endoscopy score of either two or three, signaling moderate to severe endoscopic disease. To achieve endoscopic remission, you needed to go all the way from that down to an endoscopic score of zero," he said. "This is important because this is a highly objective measure of drug efficacy."

Endoscopic remission was achieved in 41.5% of patients on 25 mg and 47.7% on 50 mg, compared to 10% with placebo. "These are amongst the highest endoscopic remission rates that we've seen, and this strong endoscopic remission data really signifies or signals the potential of this drug in moderate to severe ulcerative colitis," Panaccione said. Both doses also met key secondary endpoints, including endoscopic improvement, histologic-endoscopic mucosal improvement, and steroid-free remission, with no concerning safety signals through 44 weeks.

Is Obefazimod's Safety Profile Holding Up With Longer Exposure?

Addressing the drug's safety profile, Panaccione cautioned against over-reading early signals. "When the induction data was first released publicly, there were a few malignancies in the 50 mg dose, and I think that was a little bit misinterpreted," he said. "When we're interpreting rare safety events such as malignancy, it's important not to focus solely on the raw numbers... simple case counts can be really misleading, particularly when the amount of treatment exposure differs amongst groups."

He explained that the 50 mg group had both the greatest cumulative exposure and the most treatment-refractory patients, which would naturally be expected to produce more events. "The important thing is to look at exposure-adjusted incidence rates, and that's a more appropriate way to look at safety in general," Panaccione said.

Across the phase 2 and phase 3 programs, exposure totaled >1,700 patient-years. Rates of non-melanocytic skin cancer were consistent with published malignancy rates in UC, Panaccione said, noting that a prostate cancer and a breast cancer observed in the 50 mg group were not rare cancers and occurred in patients where they would be expected. "Certainly, the available data doesn't suggest a dose-dependent malignancy signal with obefazimod," he said. With phase 2 data now extending beyond four years, Panaccione characterized the overall benefit-risk profile as favorable.

Phase 3 ABTECT data show ~51% clinical remission and ≥40% endoscopic remission with obefazimod through week 44.

Abivax announced positive topline results from Part 2 of the phase 3 ABTECT maintenance trial evaluating obefazimod in ulcerative colitis (UC), showing clinically meaningful efficacy through week 44 in patients who did not initially respond to induction therapy. 

The data build on positive Part 1 topline results announced in early June, when both the 25 mg and 50 mg doses of obefazimod met the primary endpoint of clinical remission and all key secondary endpoints.

Remo Panaccione, MD, professor of medicine and director of the IBD Clinic at the University of Calgary, discussed the ABTECT maintenance program, obefazimod's safety profile, and where the drug could fit into an increasingly crowded UC treatment landscape in an interview with HCPLive.

Part 2 Builds on Part 1's Placebo-Adjusted Efficacy

In Part 2 of the maintenance trial, patients receiving continuous treatment with the 50 mg dose achieved the strongest outcomes across key clinical and endoscopic endpoints, further strengthening obefazimod's benefit-risk profile ahead of the company's planned new drug application (NDA) submission in the fourth quarter of 2026. The long-term safety profile remained consistent with previous studies, with no new safety signals observed.

Part 1 of the maintenance study included 580 patients who had initially responded to induction therapy and then entered the randomized, placebo-controlled maintenance study. Part 2 enrolled an additional 633 patients who had either not responded during induction or had subsequently lost response during maintenance, a population that included the largest cohort of patients with an inadequate response to a JAK inhibitor studied in a phase 3 UC trial to date.

Both the 25 mg and 50 mg doses met the primary endpoint of clinical remission, with remission rates of approximately 51% with either active dose compared with 10% with placebo, a 40-point placebo-adjusted difference

Endoscopic remission, defined as a Mayo endoscopy score of 0 or 1 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, compared with 10% on placebo

Both doses also met all key secondary endpoints, including endoscopic improvement, histologic-endoscopic mucosal improvement, and steroid-free remission

Among initial non-responders who continued on the 50 mg dose, about 37% achieved clinical remission and more than 60% achieved response

Among patients who relapsed on the 25 mg dose during maintenance and were escalated to 50 mg, clinical remission was recaptured in about 56%

Q&A: Remo Panaccione, MD, on the ABTECT Maintenance Program

You've had the opportunity to review the complete ABTECT maintenance program. What do you see as the biggest takeaway for clinicians treating patients with moderate to severe ulcerative colitis?

Before we talk about the maintenance part, it's important to recognize that these results are building upon very impressive induction data, where we saw placebo-adjusted treatment differences for the primary endpoint of clinical remission that were quite substantial. Importantly, the onset of benefit of this drug, which is a once-a-day oral, was rapid, with separation from placebo as early as week one for symptomatic response and week two for symptomatic remission.

Moving into the maintenance part, there are several takeaways. First, this is a very large, clinically relevant program. Part one of the maintenance study included 580 patients who had initially responded to induction and then entered the randomized, placebo-controlled maintenance study. Part two included an additional 633 patients who had either not responded during induction or had subsequently lost response during maintenance.

It's also important for clinicians to recognize that this study included a substantial portion of patients who were difficult to treat. In particular, it enrolled the largest cohort of patients with an inadequate response to a JAK inhibitor that we've ever studied in a phase 3 clinical trial. That's particularly important because JAK inhibitor use tends to be later-line therapy, and we know those patients don't respond as well as naive patients or patients exposed only to monoclonal antibodies.

In part one, there were two maintenance doses, 25 mg and 50 mg, and both met the primary endpoint of clinical remission at week 44. Remission rates were quite high, approximately 51% with either active dose compared to only 10% with placebo. That 40-point difference is the largest placebo-adjusted difference we've seen in a phase 3 trial. Part of that may be due to the placebo rate being quite low, which usually reflects a difficult-to-treat patient population.

In part two, among initial non-responders who continued on 50 mg, about 37% achieved remission and over 60% achieved response. Among patients who relapsed on 25 mg during maintenance and were escalated to 50 mg, clinical remission was recaptured in about 56%.

The most compelling data, though, is the objective data, endoscopic and histologic. All patients entered the trial with a Mayo endoscopy score of 2 or 3, moderate to severe endoscopic inflammation, and needed to reach a score of 0 or 1 to achieve remission. In part one, endoscopic remission was 41.5% with 25 mg and 47.7% with 50 mg, compared to only 10% with placebo. These are among the strongest endoscopic remission results we've seen in a phase 3 program. Both doses also met all key secondary endpoints, including endoscopic improvement, histologic-endoscopic mucosal improvement, and steroid-free remission. And over 44 weeks, we didn't see any safety signals that were concerning.

The maintenance data also substantially expanded the long-term safety database. How would you characterize the safety profile of obefazimod at this stage of development, and what gives you confidence in its benefit-risk profile?

I think the safety looks quite good. When the maintenance part 1 data was first released publicly, there were a few malignancies in the 50 mg dose, and I think that was a little bit misinterpreted. When interpreting rare safety events like malignancy, it's important not to focus solely on raw numbers. These events were uncommon, and simple case counts can be misleading, particularly when treatment exposure differs across groups.

With maintenance, we have more exposure, and that gives us a better picture of safety. The 50 mg group had the greatest cumulative treatment exposure and included many of the most treatment-refractory patients. When patients receive a treatment for longer, we'd naturally expect more events in that group. So the important thing is to look at exposure-adjusted incidence rates rather than raw counts.

Across both the phase 2 and phase 3 programs, there's over 1,700 patient-years of exposure. Rates of things like non-melanoma skin cancer are consistent with published malignancy rates in ulcerative colitis. There was a prostate cancer and a breast cancer in the 50 mg dose, but those aren't rare cancers, and they occurred in patients where we'd expect them. The available data doesn't suggest a dose-dependent malignancy signal with obefazimod. We have phase 2 data going out beyond four years now, and when you weigh the benefit against what we're seeing for safety, it's a very favorable benefit-risk profile.

Ulcerative colitis has become an increasingly crowded treatment landscape with numerous advanced therapies available. Based on the totality of the ABTECT data, where do you envision obefazimod fitting into clinical practice if it's approved?

You're absolutely right that it's becoming a crowded landscape. Whenever a new molecule comes into the clinic, we need to ask what it really brings to the table compared to what we already have. Here, we have a once-daily oral small molecule with a different mechanism of action than anything currently available in the clinic. That mechanism is intriguing to us because it increases expression of miR-124, a naturally occurring microRNA, which brings the immune system back into balance rather than acting as a true immunosuppressant like some of the therapies we currently have.

Articles

Abefazimod demonstrated durable, clinically meaningful maintenance efficacy through week 44 in moderate-to-severe ulcerative colitis, including patients failing induction or losing response. Across 25 mg and 50 mg dosing, clinical remission approached 51% versus 10% with placebo, alongside robust endoscopic and histologic endpoints and steroid-free remission. In refractory subsets, continued 50 mg converted ~37% of induction nonresponders to remission, while dose escalation from 25 mg to 50 mg recaptured remission in ~56%. Safety remained consistent, supported by >1,700 patient-years and no new signals.

Remo Panaccione, MD, discusses ABTECT Part 2 data: about 37% of prior non-responders achieved remission, with no new safety signals.

ABTECT Part 2 Data: Obefazimod Sustains Remission in UC

Real-World Upadacitinib Results in Ulcerative Colitis

New interim data from the ongoing PROFUNDUS study, presented at the European Crohn’s and Colitis Organisation Congress, provide important real-world insight into the effectiveness and safety of upadacitinib (Rinvoq) in patients with moderate-to-severe ulcerative colitis (UC).

While randomized controlled trials established the drug’s efficacy under tightly controlled conditions, the PROFUNDUS findings help clarify how those results translate into everyday clinical practice.

, Remo Panaccione, MD, director of the inflammatory bowel disease unit at the University of Calgary, explained that randomized controlled trials rely on strict inclusion and exclusion criteria, often excluding the complex patients physicians routinely encounter. Real-world studies like PROFUNDUS, by contrast, include patients with diverse comorbidities, varied steroid tapering approaches, and heterogeneous prior treatment histories.

“When we complement those findings from the randomized controlled trials with real world evidence, if we see that the response rates and remission rates that we're seeing in the clinical trials hold up in the real world in these complex settings, it gives us a lot more confidence that the trial results are valid and that they can be translated into our clinical practice,” Panaccione explained. “Plus, it gives us that experience in those patients that are not necessarily included in the clinical trials.”

The interim analysis evaluated 494 of the first 500 eligible adult patients (aged 18-79 years) with moderate-to-severe UC who initiated once-daily upadacitinib across 16 countries, per investigator discretion and according to the local label. Induction was initiated with the first dose of upadacitinib 45 mg at the beginning of the study. Maintenance was initiated with the start of upadacitinib 15 mg or upadacitinib 30 mg after completion of the induction phase.

Assessed endpoints included clinical response per Partial Adapted Mayo Score (PAMS), corticosteroid (CS)-free response per PAMS, clinical remission per Partial Mayo Score (PMS), absence of abdominal pain, and absence of bowel urgency at week 26.

Among the overall population at week 26, with any upadacitinib dose, 81.8% of patients achieved clinical response, 72.4% clinical remission, 66.3% no abdominal pain, and 71.9% no bowel urgency. Among those on baseline CS, 64.4% attained CS-free response. Of note, similar results were observed for all endpoints, regardless of advanced therapy status.

Among patients treated with upadacitinib induction/maintenance) at either 45/15 mg, 45/30 mg, or any upadacitinib dose, adverse event (AE) were 66.0%, 50.8%, and 51.4%, respectively. Serious AEs were 3.8%, 4.6%, and 5.7%, and severe AEs were 5.7%, 4.0%, and 5.5%. Within the subgroup of patients who experienced TEAEs potentially related to upadacitinib, as assessed by the study investigator, exhibited serious and severe AEs at 3.6%, 6.3%, 6.9%, and 7.1%, 5.4%, 6.9%, respectively.

Panaccione called attention to the consistency of the results across advanced therapy–naïve and experienced populations. Of note, in October 2025, the US Food and Drug Administration approved an updated indication statement for upadacitinib for the treatment of adults with moderately to severely active UC and moderately to severely active Crohn's disease (CD), allowing the use of upadacitinib for patients with moderately to severely active UC or CD after they have received ≥ 1 approved systemic therapy in the event tumor necrosis factor (TNF) blockers are clinically inadvisable. Previously upadacitinib was only indicated for adults who had an inadequate response or intolerance to ≥ 1 blockers.

“This data from the real world studies allows physicians to feel very confident that they can position upadacidinib in different patient populations,” Panaccione said.

Editors’ Note: Panaccione reports relevant disclosures with Abbott, AbbVie, Amgen, Boehringer Ingelheim, Bristol Myers Squibb, Gilead, Janssen, Lilly, Novartis, Takeda, and others.

R Panaccione, M Fumery, D Bettenworth, S Danese, P Morisset, M Mallick, S H Chen, J Kim, S Suravaram, G Parkes, P1073 Real-World Effectiveness, Symptomatic Improvement, and Safety of Upadacitinib in Patients With Moderate-to-Severe Ulcerative Colitis: Interim Findings From the PROFUNDUS Study, 

, Volume 20, Issue Supplement_1, January 2026, jjaf231.1254, 

https://doi.org/10.1093/ecco-jcc/jjaf231.1254

Brooks A. FDA Approves Updated Indication for Upadacitinib (Rinvoq) in IBD. HCPLive. October 13, 2025. Accessed February 20, 2026. 

https://www.hcplive.com/view/fda-approves-updated-indication-for-upadacitinib-rinvoq-in-ibd

Panaccione recaps interim PROFUNDUS data showing real-world efficacy and safety of upadacitinib (Rinvoq) for ulcerative colitis.