Protagonist Therapeutics Inc (NASDAQ:PTGX) was the biggest faller on Wall Street on Monday after the junior biopharma confirmed it has axed the phase IIb study of its flagship ulcerative colitis drug candidate mid-trial.
In mid-afternoon trading, shares were down 57.1% to US$8.76.
PTG-100 was 'futile'
California-based Protagonist said it was abandoning the trial early because interim data analysis showed PTG-100 showed that the drug was not having an effect on patients with moderate to severe ulcerative colitis.
"Using pre-specified criteria, the data monitoring committee deemed the trial to be futile based on an analysis of the primary endpoint of clinical remission," said Monday's statement.
The company stressed that the trial was not stopped due to safety concerns, and that it "remains committed" to progressing its other peptide-base assets, PTG-200 and PTG-300.
"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," said president and chief executive Dinesh Patel.
Yet to decide on chronic pouchitis study
Protagonist had been hoping to move forward with a phase II/III trial studying PTG-100 as a potential treatment for chronic pouchitis.
Given Monday's news, it said it would hold off on making a final decision until it had had a chance to fully review the interim data from the ulcerative colitis trial.