Protagonist Therapeutics announces icotrokinra data in UC, plaque PsO

Protagonist Therapeutics (PTGX) announced new data from two studies of icotrokinra, an investigational targeted oral peptide that precisely blocks the IL-23 receptor, presented at two recent medical conferences. Week 28 data from the Phase 2b ANTHEM-UC study of icotrokinra will be presented at the 2025 American College of Gastroenterology Annual Scientific Meeting, demonstrating sustained and clinically meaningful results, with all doses showing higher rates of clinical response, clinical remission, endoscopic improvement and histologic-endoscopic mucosal improvement at Week 28 compared to placebo. These outcomes build on Week 12 data that was recently presented at United European Gastroenterology Week 2025. Based on results from the Phase 2b ANTHEM-UC study, Johnson & Johnson (JNJ) has initiated the ICONIC-UC Phase 3 protocol in adults and adolescents with moderately to severely active UC, as well as the ICONIC-CD Phase 2b/3 protocol in adults with moderate to severely active Crohn’s disease. Additionally, new long-term 52-week data from the Phase 3 ICONIC-TOTAL study, presented last week at the 2025 Fall Clinical Dermatology Conference, show icotrokinra demonstrated high and durable rates of site-specific psoriasis clearance affecting these high-impact and difficult-to-treat areas of the body. 72% of patients with scalp psoriasis achieved a scalp-specific Investigator’s Global Assessment 0/1 score and 57% achieved ss-IGA 0; 85% of patients with genital psoriasis achieved a Physician’s Global Assessment of Genitalia 0/1 and 73% achieved sPGA-G 0. In the smaller subset of patients with hand/foot psoriasis, treatment with icotrokinra showed a numerically higher rate of skin clearance at Week 16, which increased through Week 52 with patients achieving a hand and/or foot Physician’s Global Assessment score of 0/1 increasing from 42% to 62%. Overall response rates among patients treated with once-daily icotrokinra were maintained through Week 52, with 67% of patients treated with icotrokinra achieving clear or almost clear skin and 44% achieving completely clear skin at Week 52. The overall response rates were also comparable among patients who received icotrokinra for all 52 weeks and those who transitioned from placebo to icotrokinra at Week 16. Across treatment groups, adverse event and serious adverse event rates were similar through Week 52 compared to those through Week 16, with no new safety signals identified.