Long-Term Guselkumab Results Advance UC Treatment Durability

New long-term extension (LTE) results from a Johnson & Johnson Phase IIb/III clinical program (QUASAR) indicate that the company’s guselkumab (Tremfya), an interleukin-23 (IL-23)–targeting monoclonal antibody (mAb), sustained clinical, endoscopic, and histologic remission outcomes for up to three years. The results, announced in February 2026) were shown in adults with moderately to severely active ulcerative colitis (UC) and reinforce an industry movement toward durability-based efficacy endpoints in inflammatory bowel disease (IBD) drug development.^1,2

Data from the program demonstrated sustained disease control through Week 140 of treatment. Clinical remission was achieved in 80.8% of patients receiving guselkumab, while 53.6% reached endoscopic remission. Additionally, 78.6% achieved histo-endoscopic mucosal improvement, reflecting combined tissue-level healing and endoscopic normalization.¹ Approximately 89% of eligible participants completed treatment through Week 140, and nearly all patients in clinical remission remained corticosteroid-free for at least eight weeks. These data support sustained inflammatory control without continued steroid dependence, according to the company.

“Ulcerative colitis is a lifelong condition that can significantly impact patients’ overall health and they need treatment options that remain effective and well-tolerated over time,” said Laurent Peyrin-Biroulet, MD, PhD, study investigator, in a company press release.¹ “The QUASAR long-term study shows the sustained ability of [Tremfya] to deliver durable results, with consistent outcomes regardless of previous biologic or JAK [Janus kinase] inhibitor treatment.”

Why is long-term remission durability becoming a key endpoint in UC trials?

UC drug development has increasingly shifted from short-term symptom reduction toward endpoints associated with long-term disease modification, including mucosal healing and sustained remission. These measures correlate with reduced flare frequency, hospitalization risk, and surgical intervention.

In the QUASAR LTE analysis, durability of response emerged as a defining outcome. Among patients who achieved clinical remission at Week 44, 87.5% maintained remission through Week 140. Treatment benefit was observed regardless of prior exposure to biologics or JAK inhibitors, suggesting consistent efficacy across treatment-experienced populations.

LTE data provide insight into treatment persistence trends, reinforcing growing regulatory emphasis on durability, safety consistency, and sustained patient benefit.³

How is targeting the IL-23 pathway reshaping inflammatory bowel disease pipelines?

Guselkumab is designed to inhibit IL-23, a cytokine central to immune-mediated inflammatory signaling. The mAb also binds CD64, a receptor expressed on IL-23–producing immune cells, representing a dual-mechanism approach supported by preclinical data. The sustained histologic and endoscopic outcomes observed across the QUASAR program underscore continued industry investment in IL-23 pathway modulation as developers pursue therapies capable of maintaining deep remission rather than episodic disease control.²

“These findings highlight the endoscopic outcomes that can be achieved with [Tremfya], raising expectations for what is possible for patients with ulcerative colitis,” said Esi Lamousé-Smith, MD, PhD, vice president, Gastroenterology Disease Area Lead, Immunology, Johnson & Johnson, in the release.¹ “Patients who achieve endoscopic remission experience fewer flare-ups and are less likely to need steroids or require surgery over time. We are energized by these findings and remain focused on delivering treatments that help more patients achieve meaningful, lasting disease control.”

Additional company-sponsored data include Phase IIb results evaluating icotrokinra, an investigational oral IL-23 receptor–targeting peptide, and pediatric safety findings for ustekinumab in Crohn’s disease, reflecting broader expansion of mechanism-based approaches across IBD populations.

Collectively, the long-term QUASAR findings contribute to evolving clinical and regulatory expectations emphasizing sustained remission, mucosal healing, and steroid independence as defining measures of therapeutic success in ulcerative colitis development.

References

1. Johnson & Johnson. TREMFYA (guselkumab) long-term data show sustained clinical and endoscopic remission in ulcerative colitis through 3 years. Press Release. Feb. 21, 2026.
2. Jairath V, Narula N, Ungaro RC., et al. Novel outcomes in inflammatory bowel disease. Journal of Crohn's and Colitis 2025;19(4): jjaf040. doi: 10.1093/ecco-jcc/jjaf040
3. FDA. Guidance for Industry, Ulcerative Colitis: Clinical Trial Endpoints (CDER, August 2016).