A Phase 2b trial of PTG-100, an investigative therapy for moderate-to-severe ulcerative colitis (UC), has been discontinued after an interim analysis deemed the study futile, according to Protagonist Therapeutics.
The randomized, double-blind Phase 2b PROPEL trial (NCT02895100), initiated in 2016, was evaluating the safety and efficacy of three daily doses of oral PTG-100 (150 mg, 300 mg, or 900 mg), for 12 weeks in people with moderate-to-severe UC.
The study’s main goal (primary endpoint) was the proportion of people UC patients on PTG-100 in clinical remission at week 12, compared to the placebo group.
Recently, an independent Data Monitoring Committee analyzed the interim results of 65 patients in the ongoing 240-patient trial who had completed 12 weeks of therapy with PTG-100.
Based on the primary endpoint criteria, the Data Monitoring Committee found the trial futile, although no safety issues were found.
“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,” Dinesh V. Patel, PhD, president and CEO of Protagonist Therapeutics, said in a press release.
“We are very grateful to the patients and investigators who participated in the PROPEL trial,” he said.
Patel added that Protagonist remains committed to its other peptide-based investigative therapies in clinical development, PTG-200 for Crohn’s disease and PTG-300 for iron overload disorders, “and to discovering new peptide-based therapeutic entities to address significant unmet medical needs.”
Protagonist Therapeutics will now wait for the full review of the PROPEL trial’s interim data to decide if it should proceed with a Phase 2/3 clinical trial of PTG-100 in chronic pouchitis, an inflammation in the lining of a pouch created during surgery to treat ulcerative colitis and other diseases.
PTG-100 is a digestive system (GI)-specific oral peptide that blocks the function of alpha-4-beta-7 integrin. This type of integrin, or cell receptor, is involved in the inflammatory response associated with inflammatory bowel diseases.