Guselkumab, known commercially as Tremfya, has gained approval in 2025 for treating both Crohn's disease and ulcerative colitis. This medication, already prescribed for plaque psoriasis and psoriatic arthritis, provides a new avenue of treatment for individuals with moderate to severe forms of inflammatory bowel diseases (IBD) who have not responded adequately to other therapies.
The Medicines and Healthcare products Regulatory Agency (MHRA) approved guselkumab on May 16, 2025. Clinical trials have demonstrated that up to 56% of Crohn's disease patients achieved clinical remission after 12 weeks of guselkumab treatment, compared to 15-22% on placebo. For ulcerative colitis, 23% of patients achieved remission after 12 weeks, versus 8% on placebo; continued treatment resulted in 50% remission after 44 weeks, compared to 19% on placebo.
Guselkumab functions by selectively blocking IL-23, a protein instrumental in causing inflammation. It can be administered via intravenous infusion or subcutaneous injection for Crohn's disease, while ulcerative colitis treatment starts with intravenous infusions. The FDA approved guselkumab for Crohn's in March 2025, recognizing it as the first IL-23 inhibitor offering both subcutaneous and intravenous options.