Johnson & Johnson announces positive results from phase 3 FUZION study of Tremfya in perianal fistulizing Crohn's disease

Johnson & Johnson announced results from the phase 3 FUZION study evaluating Tremfya (guselkumab) in adults with active perianal fistulizing Crohn's disease (CD). At Week 24, Tremfya demonstrated significantly higher rates of combined fistula remission, a highly stringent endpoint defined as complete external closure of draining fistulas and absence of fluid collection on MRI, compared to placebo. Remission in patients with this complicated manifestation remains difficult to achieve, and this is the first randomized control trial of an approved therapy in inflammatory bowel disease (IBD) that demonstrates efficacy in adults with active perianal fistulizing Crohn's disease in 20 years. These late-breaking data are among the 32 company-sponsored abstracts at Digestive Disease Week (DDW) 2026.

Tremfya met the primary endpoint of combined fistula remission at Week 24, defined as complete closure of all external fistula openings with no drainage, without development of new fistulas and no evidence of underlying fluid collections on MRI. Combined fistula remission was achieved by 28.3% of patients receiving Tremfya 100 mg every 8 weeks (q8w) and 27.0% of patients receiving Tremfya 200 mg every 4 weeks (q4w), compared with 10.3% for placebo.

The treatment differences versus placebo were statistically significant for both the 100 mg q8w and 200 mg q4w dosing regimens (p=0.007 and p=0.013, respectively). Adverse events through 24 weeks were consistent with the known safety profile of Tremfya in CD.

"The pain, swelling and persistent drainage associated with perianal fistulizing Crohn's disease can be profoundly disruptive to patients' daily lives," said Laurent Peyrin-Biroulet, MD, PhD, study investigator. "Achieving durable fistula closure without repeated surgical interventions remains a significant unmet need. The results from the FUZION study demonstrate the ability of Tremfya to achieve combined fistula remission, which is an exciting step forward for patients, expanding what's possible for managing this debilitating and chronic condition."

"It has been more than two decades since a highly rigorous study has been dedicated to perianal fistulizing Crohn's disease, a very difficult-to-treat and complex manifestation of this already challenging condition," said Ludovic de Beaucoudrey, PhD, J&J Innovative Medicine vice president, immunology, global medical affairs, gastroenterology and autoantibody. "Building on decades of experience in immunology, Johnson & Johnson continues to address areas of significant unmet need, and the FUZION study reflects our commitment to delivering meaningful, evidence-based advances for patients and the healthcare providers who care for them."

A fistula is an abnormal connection or tunnel that develops between the intestine and another organ or the skin, typically arising when inflammation causes ulceration in the intestinal wall or surrounding tissue. Over time, these ulcers may penetrate the full thickness of the bowel, forming a channel that allows infected material to drain. Perianal fistulizing Crohn's disease affects nearly 25% of patients with CD and represents a severe, often debilitating manifestation of the disease that has profound impacts on a person's physical and mental health. It is characterized by pain, swelling, persistent drainage, recurrent abscesses, and a frequent need for surgical intervention.

As another example of this commitment for evidence-based advances for CD patients and providers, Johnson & Johnson is also initiating the CHARGE study, the first head-to-head study of IL-23 inhibitors in IBD, which will evaluate Tremfya compared to risankizumab in treatment of Crohn's disease. Trial sites are now open for patient enrollment. 

FUZION is a randomized, placebo-controlled, double-blind, multicenter, phase 3 study designed to evaluate the efficacy and safety of Tremfya in adults with perianal fistulizing Crohn's disease. Patients enrolled in the study had one or more active draining perianal fistulas confirmed by blinded central MRI review, CD Activity Index [CDAI] <350, and inadequate response to oral corticosteroids, azathioprine, 6-mercaptopurine, methotrexate, or up to 2 advanced therapy classes. Patients were randomized 2:2:1 to receive Tremfya 200 mg intravenous (IV) induction at Weeks 0, 4, 8 weeks followed by Tremfya 100 mg subcutaneous (SC) induction every 8 weeks (q8w); or Tremfya 200 mg IV infusion in at Weeks 0, 4, 8 weeks followed by Tremfya 200 mg SC every 4 weeks (q4w); or placebo.

Crohn's disease is one of the two main forms of inflammatory bowel disease, which affects an estimated three million Americans and an estimated four million people across Europe. Crohn's disease is a chronic inflammatory condition of the gastrointestinal tract with no known cause, but the disease is associated with abnormalities of the immune system that could be triggered by a genetic predisposition, diet, or other environmental factors. Symptoms of Crohn's disease can vary, but often include abdominal pain and tenderness, frequent diarrhoea, rectal bleeding, weight loss, and fever. Currently no cure is available for Crohn's disease.

Developed by Johnson & Johnson, Tremfya is the first fully-human, dual-acting monoclonal antibody designed to neutralize inflammation at the cellular source by blocking IL-23 and binding to CD64 (a receptor on cells that produce IL-23). Findings for the dual-acting mechanism are limited to in vitro studies that demonstrate guselkumab binds to CD64, which is expressed on the surface of IL-23 producing cells in an inflammatory monocyte model. The clinical significance of this finding is not known.

Tremfya is a prescription medicine approved in the US to treat:

• adults and children 6 years and older who also weigh at least 88 pounds (40 kg) with moderate to severe plaque psoriasis who may benefit from taking injections or pills (systemic therapy) or phototherapy (treatment using ultraviolet or UV light).
• adults and children 6 years and older who also weigh at least 88 pounds (40 kg) with active psoriatic arthritis.
• adults with moderately to severely active ulcerative colitis.
• adults with moderately to severely active Crohn's disease.