Protagonist Therapeutics Surges 42% on Strong Phase 2b Data for Oral IL-23R Peptide in Ulcerative Colitis

▎Armstrong

On March 10, 2025, Johnson & Johnson announced the Phase 2b clinical data of its oral IL-23R cyclic peptide inhibitor for the treatment of ulcerative colitis. The study met the primary endpoint of clinical remission and is expected to change the treatment landscape for ulcerative colitis.

After the announcement, Protagonist Therapeutics' stock price surged by 42%, reaching a market value of $3.3 billion.

JNJ-2113 (Icotrokinra) is the core pipeline of Protagonist, which is clinically developed in collaboration with Johnson & Johnson, while exploring multiple indications.

Protagonist's collaboration with Johnson & Johnson on JNJ-2113 is worth up to 1 billion USD. Protagonist has already received 337.5 million USD in upfront and milestone payments, with an additional 630 million USD in potential milestone payments, as well as a 6-10% sales royalty.

The design of the Phase 2b clinical trial for ulcerative colitis that was recently announced includes three dosage groups and a placebo group, with a 12-week treatment period to observe the primary endpoint of clinical response rate.

After 12 weeks of treatment, the clinical response rate was 63.5%, and the clinical remission rate was 30.2%.

Compared with other therapeutic drugs, JNJ-2113 demonstrated a higher clinical response rate after 12 weeks of treatment, with a more significant advantage over IL-23 antibodies.

The trend in clinical remission rate data is consistent with this.

Summary

In the past two years, the biggest hotspot in inflammatory bowel disease has been the new target TL1A. As clinical progress advanced, several high-profile deals were consecutively reached, including Merck's $10.8 billion acquisition of Prometheus, Roche's $7.1 billion acquisition of Telavant, Sanofi’s $1.5 billion licensing of Teva’s TL1A antibody, and AbbVie’s $1.7 billion licensing of Mabwell’s long-acting TL1A antibody. The latest data from Protagonist indicates that oral IL-23R cyclic peptides also have the potential to bring breakthrough efficacy to inflammatory bowel disease, setting another benchmark for the direction of orally administered cyclic peptide drugs iterating on antibody therapies in the chronic disease field.