Guselkumab (Tremfya) Shows Consistent Fistula Remission in Crohn Disease

Johnson & Johnson (J&J) announced new phase 3 subgroup analyses showing consistent combined fistula remission with guselkumab (Tremfya) in Crohn disease with perianal fistula, including among patients with prior biologic exposure.¹ The prespecified analyses, from the FUZION study, are being presented at the American College of Gastroenterology (ACG) 2026 Annual Scientific Meeting and build on previously reported week 24 results in the overall population, the company said in its October 12, 2026 announcement.¹

In the overall study population, 28% of patients receiving guselkumab 100 mg subcutaneously (SC) every 8 weeks (q8w) and 27% receiving 200 mg SC every 4 weeks (q4w) achieved the composite endpoint of combined fistula remission at week 24, compared with 10% receiving placebo, making guselkumab the only interleukin-23 (IL-23) inhibitor to demonstrate efficacy in a dedicated, randomized, placebo-controlled trial in this patient population.¹^,²

"Perianal fistula remain one of the most debilitating manifestations of moderate to severe [Crohn] disease, and many patients continue to experience persistent drainage, pain, and complications," said Bruce Sands, MD, MS, Dr. Burrill B. Crohn professor of medicine at the Icahn School of Medicine and chief, Division of the Dr. Henry D. Janowitz Division of Gastroenterology, Mount Sinai Health System, in the release.¹ "These subgroup analyses show that the outcomes observed with TREMFYA were consistent across clinically important patient populations, further strengthening the evidence supporting its use in this difficult-to-treat patient population."

What did the new subgroup analyses show?

The new prespecified analyses found greater week 24 combined fistula remission with guselkumab versus placebo across several clinically important subgroups.¹^,² Among patients with higher baseline disease activity (Crohn Disease Activity Index of 220 or higher), 30% and 21% achieved remission with the 100 mg q8w and 200 mg q4w regimens, respectively, versus 0% with placebo.¹^,² Among patients with prior biologic exposure, remission rates were 21% and 29%, respectively, versus 5% with placebo.¹^,² Results were also consistent by baseline proctitis status: 26% and 27% among patients with proctitis versus 12% with placebo, and 29% and 27% among patients without proctitis versus 10% with placebo.¹^,² J&J said adverse events were consistent with guselkumab's known safety profile in Crohn disease.¹

Why does perianal fistula need its own dedicated trial?

FUZION is the first dedicated, randomized, placebo-controlled phase 3 trial in Crohn disease with perianal fistula in more than 20 years, building on positive topline results reported earlier in 2026 showing combined fistula remission of up to 28% across guselkumab's dosing groups.¹^,³ Perianal fistula affects nearly 25% of patients with Crohn disease and often causes persistent drainage, abscesses, and a need for surgery.¹^,⁴

"FUZION was designed to generate rigorous evidence specifically in [Crohn] disease with perianal fistula, helping us deepen our understanding of how TREMFYA can address an area of unmet need," said David M. Lee, MD, PhD, global immunology therapeutic area head at Johnson & Johnson, in the release.¹

How does guselkumab work, and what else is it approved for?

Guselkumab is an IL-23 inhibitor that J&J describes as the only approved dual-acting monoclonal antibody in inflammatory bowel disease that both blocks IL-23 and binds to CD64, a receptor on the IL-23-producing cells. This dual mechanism is based on in vitro studies of unknown clinical significance.¹ Guselkumab, made by Janssen Biotech, a J&J company, is already approved in the United States for plaque psoriasis, psoriatic arthritis, ulcerative colitis, and Crohn disease. The company’s latest data concern a specific, difficult-to-treat Crohn disease subpopulation rather than a new approval.¹

What are the limitations?

These are subgroup analyses of already-reported overall FUZION data rather than a new, independently powered trial, and several subgroups are relatively small, limiting the precision of each estimate.¹^,² Guselkumab's CD64-binding mechanism is based on in vitro data only, with clinical significance not yet known.¹

References

1. Johnson & Johnson. New Tremfya (guselkumab) study shows consistent perianal fistula remission across key Crohn's disease patient subgroups. Press release. Published October 12, 2026. Accessed October 13, 2026. https://www.prnewswire.com/news-releases/new-tremfya-guselkumab-study-shows-consistent-perianal-fistula-remission-across-key-crohns-disease-patient-subgroups-302906079.html
2. Sands BE, Hart A, et al. Efficacy of guselkumab in perianal fistulizing Crohn's disease: week 24 results from the phase 3, randomized, double-blind, placebo-controlled, multicenter FUZION study. Abstract P5691. Presented at American College of Gastroenterology Annual Scientific Meeting; October 9-14, 2026; Nashville, Tennessee.
3. Peyrin-Biroulet L, et al. Guselkumab for perianal fistulizing Crohn's disease: week 24 results from the phase 3, randomized, double-blind, placebo-controlled, multicenter FUZION study. Abstract 1058b. Presented at: Digestive Disease Week; May 2-5, 2026. Accessed May 5, 2026. https://www.prnewswire.com/news-releases/johnson--johnson-study-shows-tremfya-guselkumab-is-the-first-and-only-il-23-inhibitor-to-demonstrate-efficacy-in-perianal-fistulizing-crohns-disease-302760610.html
4. Anandabaskaran S, Hanna L, Iqbal N, et al. Where are we and where to next?-the future of perianal Crohn's disease management. J Clin Med. 2023;12(19):6379. doi:10.3390/jcm12196379