Research & Development
Phase 2a Study of Vibegron for the Treatment of Irritable Bowel Syndrome Pain Did Not Meet Primary Endpoint
24 November 2020 - - US-based biopharmaceutical company Urovant Sciences (NASDAQ: UROV) reported disappointing topline data from the Phase 2a randomized, double blind, placebo-controlled clinical trial evaluating once-daily vibegron 75 mg in women with abdominal pain due to irritable bowel syndrome with IBS-D (diarrhea) and IBS-M (mixed IBS), the company said.

A total of 222 female IBS patients were enrolled at 35 sites in the United States, 189 of whom completed the 12-week study.

In the primary efficacy analysis, the study did not meet the primary endpoint with 40.9% of vibegron IBS-D patients achieving at least a 30% improvement in average worst abdominal pain over the week 12 period, compared to 42.9% in the placebo group.

A responder was defined as a subject with at least a 30 % decrease in "worst abdominal pain in the past 24 hours" compared to the weekly baseline average over the 12-week period.

The most important secondary endpoint demonstrated 42.4% of Global Improvement Scale responders at Week 12 for IBS-D patients in the vibegron group, compared with 33.3% for placebo but this was not statistically significant for the IBS-D, IBS-M or the overall IBS population.

Urovant will continue to analyze the full data set of this study.

Vibegron was very well tolerated in the study and did not lead to any worsening of IBS symptoms. Discontinuation rates due to adverse events were 0% in the vibegron group and 2.7% in placebo.

The frequency of serious adverse events was similar across treatment arms with 1 serious adverse effect in the placebo group and 2 in the vibegron treatment group which were not considered treatment related by the investigator.

The adverse events reported for vibegron were in the placebo range (33.3% in both groups).

In particular, the adverse events of worsening of IBS were 2.7% for both vibegron and placebo and the adverse event of diarrhea was 0% for vibegron 75 mg and 1.8% for placebo respectively.

Vibegron is an oral, once-daily small molecule beta-3 agonist that is being evaluated for overactive bladder, OAB in men with benign prostatic hyperplasia (OAB+BPH) and for abdominal pain associated with irritable bowel syndrome.

Urovant has submitted a New Drug Application for vibegron in OAB to the US Food and Drug Administration's, which has an assigned Prescription Drug User Fee Act (PDUFA) goal date of December 26th.

Data available to date on vibegron, which includes an international Phase 3 safety and efficacy study for OAB, indicate vibegron is well tolerated.

If approved, vibegron would be the first new branded prescription drug for the treatment of OAB in nearly a decade and would offer these suffering patients another potential treatment option.

Urovant Sciences is a clinical-stage biopharmaceutical company focused on developing and commercializing innovative therapies for urologic conditions.