- Phase 3 FUZION: guselkumab (TREMFYA) achieved combined fistula remission at Week 24 in 28.3% (100 mg q8w) and 27.0% (200 mg q4w) versus 10.3% for placebo.
- Both dosing regimens were statistically significant versus placebo (p=0.007 and p=0.013) and adverse events through 24 weeks were consistent with the known safety profile.
- FUZION was a randomized, double-blind, placebo-controlled, multicenter trial enrolling adults with active draining perianal fistulas confirmed by central MRI and prior inadequate response to conventional or up to two advanced therapies.
- Johnson & Johnson has opened sites for CHARGE, the first head-to-head IL-23 inhibitor study in IBD comparing TREMFYA (guselkumab) to risankizumab.
Key results
In the Phase 3 FUZION study, guselkumab (TREMFYA) met the primary endpoint of combined fistula remission at Week 24—defined as complete external closure of all draining fistulas, no new fistulas and no fluid collections on MRI—with rates of 28.3% for 100 mg SC every 8 weeks (after IV induction) and 27.0% for 200 mg SC every 4 weeks versus 10.3% for placebo (p=0.007 and p=0.013, respectively).
Study design and population
FUZION was a randomized, double‑blind, placebo‑controlled, multicenter Phase 3 trial in adults with one or more active draining perianal fistulas confirmed by blinded central MRI review, CDAI <350, and inadequate response to corticosteroids, azathioprine/6‑mercaptopurine, methotrexate, or up to two prior advanced therapy classes; patients were randomized 2:2:1 after IV induction with 200 mg at Weeks 0, 4 and 8 to receive maintenance 100 mg SC q8w, 200 mg SC q4w, or placebo.
Safety
Adverse events through 24 weeks were consistent with the known safety profile of guselkumab in Crohn’s disease.
Disease context and next steps
Perianal fistulizing Crohn’s disease affects about 25% of patients with CD and is difficult to treat; sites are open for CHARGE, a head‑to‑head IL‑23 inhibitor study comparing guselkumab to risankizumab, and a dual IL‑23/CD64 binding mechanism has been observed in vitro with unknown clinical significance.
