Phase 2 Trial of Icotrokinra for Patients with Ulcerative Colitis

Monoclonal antibodies targeting the interleukin-23 pathway are effective in treating inflammatory bowel disease. However, these therapies must be administered intravenously or by subcutaneous injection.

We conducted a phase 2b, double-blind, randomized trial of oral icotrokinra, a peptide that blocks the interleukin-23 receptor, in adults with moderately to severely active ulcerative colitis. Participants were assigned to receive icotrokinra at a once-daily dose of 400 mg, 200 mg, or 100 mg or placebo. The primary end point was clinical response at week 12. Secondary end points included clinical remission, remission of symptoms, and endoscopic improvement at week 12.

A total of 252 participants underwent randomization: 63 were assigned to the 400-mg group, 62 to the 200-mg group, 64 to the 100-mg group, and 63 to the placebo group. All the doses of icotrokinra were superior to placebo with respect to a clinical response at week 12, which occurred in 63% of the participants in the 400-mg group, 58% in the 200-mg group, and 55% in the 100-mg group, as compared with 27% in the placebo group (P<0.001 for all comparisons with placebo). The percentage of participants with clinical remission at week 12 was also significantly higher in the 400-mg group than in the placebo group (30% vs. 11%, P = 0.006), as were the percentage of participants with symptomatic remission (46% vs. 19%, P<0.001) and the percentage of participants with endoscopic improvement (37% vs. 14%, P = 0.002). Clinical remission at week 12 occurred in 24% of the participants in the 200-mg group (P = 0.054 for the comparison with placebo); in accordance with the fixed-sequence testing procedure to account for multiple comparisons, no further formal testing of secondary end points was conducted. Through week 28, the percentage of participants with adverse events was 60% in the 400-mg group, 66% in the 200-mg group, 66% in the 100-mg group, and 62% in the placebo group. For serious adverse events, the percentages were 2%, 5%, 0%, and 10%, respectively.

Among participants with moderately to severely active ulcerative colitis, a clinical response at week 12 was significantly more common with once-daily oral icotrokinra at each of three tested doses than with placebo. (Funded by Johnson & Johnson; ANTHEM-UC ClinicalTrials.gov number, NCT06049017.).