The oral beta-3 agonist vibegron, taken once daily at either 50 mg or 100 mg, is well tolerated and results in clinically and statistically significant reductions in daily micturitions, urge incontinence, and urgency episodes, according to an 8-week phase IIb study presented at the Society of Urodynamics, Female Pelvic Medicine, & Urogenital Reconstruction (SUFU) winter meeting in Austin, TX.
A drug for overactive bladder in the beta-3 alpha-receptor agonist class hasn’t been approved since mirabegron (Myrbetriq), which has been on the market for several years, according to presenting author Henry David Mitcheson, MD, a urologist in Brighton, MA.
Vibegron, he says, is novel in its selectivity.
“It actually has a very profound selectivity for beta 3 adrenergic receptor—more than 9,000-fold selectivity for beta-3, compared to beta-1 and beta-2. And it has a very favorable clinical and preclinical pharmacokinetic, pharmacodynamics, and toxicological profile,” Dr. Mitcheson told Urology Times.
For the trial, researchers studied 1,395 patients, ages 18 to 75 years, who were randomized to receive once-daily vibegron at a range of doses, including 3 mg, 15, mg, 50 mg, or 100 mg; placebo; tolterodine (Detrol); or a combination of tolterodine and vibegron at either 50 mg or 100 mg. Most of those studied were women, and more than 80% had overactive bladder-wet.
The antimuscarinic antagonist tolterodine was the gold standard drug treatment for overactive bladder. While it continues to be an excellent option, solifenacin (Vesicare) likely is today’s preferred treatment, according to Dr. Mitcheson.
Researchers found vibegron at 50 mg and 100 mg was more effective than tolterodine monotherapy, at 4 mg daily. The combination was as effective at vibegron alone at both doses.
“The take-home message was that, in this dose-ranging study, doses of vibegron at 50 mg and 100 mg were very efficacious in reducing urgency, urge incontinence, and daily micturition numbers. Vibegron was as effective or more so than tolterodine alone,” Dr. Mitcheson said.