Protagonist Therapeutics, Inc. announced that it has initiated a global Phase 2b induction study in ulcerative colitis with PTG-100, an oral peptide that targets alpha4beta7 integrin. The aim of this randomized, double-blind, placebo-controlled, adaptive design study is to evaluate the safety/tolerability and efficacy of PTG-100 in approximately 240 adult ulcerative colitis patients with moderate to severe active disease. Patients will be randomized to one of four dose arms (150mg/300mg/900mg PTG-100 or placebo) for 12 weeks of once-daily oral dosing, followed by four weeks of safety follow-up. An interim futility analysis is expected to be performed in the second half of 2017, and if futility criteria are not met, one or two PTG-100 optimal doses will be selected for continued randomization of the remaining patients. The primary efficacy endpoint of the study is clinical remission (as defined by rectal bleeding, stool frequency, and endoscopic subscores of the Mayo Score). Secondary endpoints include additional clinical and safety assessments, as well as pharmacokinetic, pharmacodynamic and other biomarker measurements of disease activity. PTG-100 is a potential first-in-class product candidate that is being developed initially for the potential treatment of moderate-to-severe active ulcerative colitis. Alpha4beta7 integrin is considered to be one of the most gastrointestinal-specific biological targets for inflammatory bowel disease due to its binding to MAdCAM-1, a cell membrane protein that resides mostly in the gastrointestinal (GI) vasculature.