Vibegron Effective In Long-Term Treatment Of Overactive Bladder

Vibegron is safe and shows lasting efficacy in treatment of overactive bladder (OAB), according to a company-funded extension trial of an earlier successful 12-week study.

Vibegron, marketed as Gemtesa by Urovant Sciences, was approved for treating OAB by the U.S. Food and Drug Administration (FDA) in December 2020.

"There is a large unmet need for medications for patients with bladder symptoms of urinary urgency, frequency, and incontinence," lead author Dr. David Staskin of St. Elizabeth Medical Center/Steward Health, in Boston, told Reuters Health by email.

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"In addition to the sustained efficacy, (vibegron) was well tolerated," he added. "The recent FDA approval based on the findings of this study will provide an important addition to treatment options which will benefit patients."

In the original phase-3 study, funded by Urovant Sciences, more than 1,500 patients received once-daily vibegron 75 mg or tolterodine 4 mg or placebo. In the extension study, those receiving active treatment continued to do so, whereas placebo patients were randomized 1:1 to double-blind receipt of vibegron or tolterodine.

Five hundred and five patients (mean age, 61 years), most of whom (78.8%) were women with wet OAB, received at least one dose of vibegron or tolterodine, and 430 completed the 40-week extension study. The primary outcome was safety, measured by incidence of adverse events.

Twelve patients discontinued treatment because of adverse events, amounting to 1.5% of the vibegron group and 3.4% of those given tolterodine, Dr. Staskin and his colleagues report in The Journal of Urology.

Hypertension, occurring at more than 8% in both groups, was the most common adverse event, followed by headache, but no clinically meaningful differences were seen between groups in the overall incidence or severity of adverse events. Dry mouth, however, was reported more often with tolterodine (5.2%) than with vibegron (1.8%).

Improvements in efficacy endpoints were maintained for patients receiving vibegron for 52 weeks. Least-squares mean change from baseline to 52 weeks in daily micturitions showed a drop of 2.4 for vibegron and 2.0 for tolterodine.

Corresponding reductions in urge urinary incontinence episodes were 2.2 and 0.7, and for total incontinence episodes, 2.5 and 1.9.

Seventy-one percent of the patients with wet OAB who received vibegron had a reduction in total incontinence episodes of 50% or more, 61% had a reduction of 75% or more and 41% achieved a 100% reduction. For tolterodine, the proportions were 62%, 54% and 34%.

Dr. Staskin has financial ties to Urovant Sciences, as do a number of his coauthors, some of whom are employees.

—David Douglas

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