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Clinical Trials

Protagonist Therapeutics stops ulcerative colitis trial of PTG-100

Published 28 March 2018

Protagonist Therapeutics said it is discontinuing the Phase 2b PROPEL study of PTG-100, its investigational oral GI-restricted alpha-4-beta-7 integrin antagonist peptide, in patients with moderate to severe ulcerative colitis (UC).

This decision followed a planned interim analysis by an independent Data Monitoring Committee (DMC) of unblinded efficacy and safety data from the first 65 patients from the ongoing 240 patient trial who had completed the 12 week treatment with PTG-100.

Using pre-specified criteria, the DMC deemed the trial to be futile based on an analysis of the primary endpoint of clinical remission. No safety concerns were noted in the analysis.

Based on the DMC's recommendation received after the market close on Friday, and while further review of the data is being conducted, Protagonist is notifying PROPEL trial investigators that randomization of potential participants and further treatment of patients currently in the study will be discontinued.

Additionally, the Company will postpone its decision about the initiation of a Phase 2/3 clinical trial of PTG-100 in chronic pouchitis until after its full review of the interim data from the UC PROPEL study.

Protagonist Therapeutics president and  CEO Dr Dinesh Patel said: "We are very disappointed with this futility-based outcome which was also accompanied by an unexpectedly high placebo rate. We will conduct an extensive review of the complete dataset on the totality of patients enrolled in the trial before making any further decisions about the future development of PTG-100.

"We are very grateful to the patients and investigators who participated in the PROPEL trial. Protagonist remains committed to progressing its other peptide-based assets currently in clinical development, PTG-200 and PTG-300, and to discovering new peptide-based therapeutic entities to address significant unmet medical needs."

The Phase 2b PROPEL trial is a global, randomized, double-blind, placebo-controlled, two-stage adaptive clinical trial to assess the safety, efficacy, and dose-optimization of three doses (150mg, 300mg, or 900mg) of PTG-100 compared to placebo for 12 weeks in patients with moderate to severe ulcerative colitis.

 The primary efficacy endpoint of the study is the proportion of patients who achieve clinical remission as defined by rectal bleeding, stool frequency, and endoscopic subscores of the Mayo score.

Source: Company Press Release