Bridge Biotherapeutics (KQ288330) announced the first patient dosing of BBT-401 at mid to high doses in its proof of clinical principle (PoCP) study to examine the drug's efficacy and safety in active ulcerative colitis (NCT04596293). The Phase IIa, is a two-phase study, with a randomized, double-blind, placebo-controlled induction phase, followed by a response-adaptive, double-blind extension phase. This multinational study will assess the safety and efficacy profiles of the investigational drug in 36 patients with moderate to severe ulcerative colitis, by activating 36 clinical trial sites across 5 countries (USA, Republic of Korea, New Zealand, Poland and Ukraine). The primary and secondary endpoints of the study consist of efficacy and safety assessments measured 8 weeks after drug administration. These include the clinical response and remission rates determined from the total Mayo score as well as the endoscopic remission rate, which is calculated based on the Mayo endoscopic subscore. Upon the completion of the low dose study, which was the first-in-patient study for BBT-401, the drug formulation has been enhanced in terms of its drug delivery and distribution to the ileum and distant colon. The enhanced drug delivery and distribution profile was evaluated via the in vitro Simulator of the Human Intestinal Microbial Ecosystem (SHIME®) model. BBT-401, an investigational drug with the potential to exhibit treatment efficacy in inflammatory diseases such as ulcerative colitis, is a GI-tract restricted small molecule Pellino-1 inhibitor. Pellino proteins serve as scaffold proteins that bind to proteins in inflammatory signaling pathways, including IRAK4, MyD88 and to RIPK1 in various physio-pathological conditions. In conjunction with the orally administered PoCP study, a proof of mechanism trial has been initiated in New Zealand, exploring the efficacy and safety of a rectal administration of BBT-401 in patients with active ulcerative colitis.