Protagonist Therapeutics announces icotrokinra data in UC

Protagonist Therapeutics (PTGX) announced additional Week 12 results from the Phase 2b ANTHEM-UC study of icotrokinra, an investigational targeted oral peptide that selectively blocks the IL-23 receptor, in adults with moderately to severely active ulcerative colitis. The study met its primary endpoint, with all once-daily icotrokinra dose groups achieving clinical responsea at Week 12 and showing clinically meaningful improvements versus placebo across key secondary endpoints.1 These results underscore the potential of icotrokinra to deliver a valuable combination of significant therapeutic benefit and a favorable safety profile with once-daily oral dosing and are featured at United European Gastroenterology Week 2025. At Week 12, patients treated with 400 mg of icotrokinra once daily achieved a clinical response rate of 63.5% versus 27% for placebo, while patients treated with 200 mg and 100 mg of icotrokinra once daily achieved 58.1% and 54.7% response rates, respectively. Across multiple secondary endpoints, in the 400 mg icotrokinra group, significantly greater proportions of patients achieved clinical remission, symptomatic remission, and endoscopic improvement at Week 12 compared to placebo. Both the 200 mg and 100 mg once-daily dosing groups also showed meaningful improvements in these secondary endpoints relative to placebo. All icotrokinra doses demonstrated higher rates of symptomatic remission compared to placebo as early as Week 4. Similar proportions of participants reported adverse events and serious adverse events through Week 12 across all icotrokinra dose groups and the placebo group. Based on results from the Phase 2b ANTHEM-UC study, a Phase 3 trial in ulcerative colitis will be initiated. Icotrokinra is also being studied in the pivotal Phase 3 ICONIC program in moderate-to-severe plaque psoriasis and the ICONIC-PSA 1 and ICONIC-PSA 2 studies in active psoriatic arthritis. A New Drug Application was submitted to the U.S. Food and Drug Administration in July 2025 seeking the first approval of icotrokinra for the treatment of adults and pediatric patients 12 years of age and older with moderate to severe plaque psoriasis.