09:25 AM EDT, 03/10/2025 (MT Newswires) -- Protagonist Therapeutics ( PTGX ) and Johnson & Johnson ( JNJ ) said a phase 2b study of the investigational targeted oral peptide icotrokinra in adults with moderately to severely active ulcerative colitis met the primary endpoint of clinical response in three dose levels at week 12, with a "favorable" safety profile.

The companies said the study, conducted by Johnson & Johnson ( JNJ ), also showed "clinically meaningful" differences compared with placebo in key secondary endpoints of clinical remission, symptomatic remission, and endoscopic improvement.

At the highest dose level, the trial achieved a 63.5% clinical response rate at week 12 compared with 27% for placebo, and a clinical remission rate of 30.2% compared with 11.1% for placebo, according to the companies. Remission and response rates continued to improve through week 28, they added.

Shares of Protagonist and Johnson & Johnson ( JNJ ) were up more than 37% and 0.6%, respectively, in recent premarket activity.