Johnson & Johnson has reported three-year clinical remission data for guselkumab in Crohn’s disease, alongside Phase 3 findings on perianal fistula remission at 48 weeks.

The results from the GALAXI 2 and 3 and FUZION studies were presented at United European Gastroenterology Week 2026.

Three-year remission outcomes in Crohn’s disease

In the GALAXI studies, as-observed data at Week 144 showed clinical remission in 94% of patients receiving guselkumab 100 mg every eight weeks and 91% receiving 200 mg every four weeks.

Clinical remission was defined as a Crohn’s Disease Activity Index (CDAI) score below 150. The corresponding results were based on 172 of 183 patients in the 100 mg group and 185 of 204 in the 200 mg group.

Endoscopic remission, assessed using the Simple Endoscopic Score for Crohn’s Disease, was achieved by 52% of patients receiving 100 mg every eight weeks and 61% receiving 200 mg every four weeks. The respective results were 89 of 172 patients and 119 of 195 patients.

The analysis also found 90-day corticosteroid-free clinical remission in 89% of patients receiving the lower maintenance dose and 88% receiving the higher dose.

However, the findings represent patients who remained on treatment and had data available at Week 144. Of the 582 patients included in the reported analysis, 432 continued treatment through three years. The results therefore should not be interpreted as remission rates across all patients who originally entered the studies.

Safety findings through Week 144 were consistent with the known safety profile of guselkumab in Crohn’s disease.

Fistula remission findings at 48 weeks

The Phase 3 FUZION study investigated guselkumab in adults with Crohn’s disease and perianal fistulas, a complication that can cause persistent drainage, pain and substantial disruption to daily life.

At Week 48, combined clinical and radiological fistula remission in the group initially assigned to guselkumab 100 mg every eight weeks increased from 28% at Week 24 to 35%.

In the group receiving 200 mg every four weeks, combined fistula remission was 26% at Week 48, compared with 27% at Week 24.

The results require careful interpretation because patients in the 100 mg group could undergo blinded dose adjustment to 200 mg every four weeks at Week 24. The Week 48 findings for this group included patients who had undergone that adjustment.

Combined fistula remission required complete closure of all external openings, no new fistulas or abscesses, no drainage and the absence of significant fluid collections on magnetic resonance imaging (MRI).

Professor Ailsa Hart, consultant gastroenterologist and study investigator, said: “Perianal fistula remains one of the most debilitating complications of Crohn’s disease, where achieving durable disease control beyond symptom improvement is a challenge.”

She added: “The latest findings from the FUZION study show that patients treated with guselkumab maintained or improved upon the clinical benefits observed at Week 24, providing encouraging evidence for its use in this patient population.”

Further evidence for long-term disease management

Crohn’s disease is a chronic inflammatory bowel disease that can affect the gastrointestinal tract and cause symptoms including abdominal pain, diarrhoea, fatigue and weight loss. Perianal fistulas are a particularly challenging manifestation that may require a combination of medical and surgical management.

Guselkumab is an interleukin-23 (IL-23) inhibitor that targets the IL-23p19 subunit. It is approved for adults with moderately to severely active Crohn’s disease who have had an inadequate response, lost response or been intolerant to conventional or biological treatment.

Marianne Radcliffe, CEO of Crohn’s & Colitis UK, said: “We know that for many people with fistulising Crohn’s disease, finding an effective long-term treatment can be a real struggle. The condition can have a major impact on everyday life, so it’s encouraging to see findings like these,”

She added: “They bring hope that more people may be able to achieve fistula healing and improve their overall wellbeing. We welcome further research into new treatment options and look forward to seeing what future studies reveal.”

The GALAXI long-term extension will continue to assess clinical, endoscopic and safety outcomes through five years. The new findings add to the evidence on sustained remission with guselkumab, while further follow-up will help establish the durability of its effects and its role in managing complex Crohn’s disease.