Selective beta-3 adrenergic agonist
Overactive bladder (OAB)
Approved in the US
GEMTESA® (vibegron) is a new oral medication indicated for the treatment of overactive bladder (OAB) with signs of urge urinary incontinence (UUI), urgency and urinary frequency in adults.
Developed by Urovant Sciences, a subsidiary of Sumitovant Biopharma, GEMTESA is available as an oral once-daily, oval, light green, film-coated tablets in 75mg strength.
A new drug application (NDA) for GEMTESA was submitted to the US Food and Drug Administration (FDA) in December 2019, which was accepted for review in March 2020.
The FDA approved GEMTESA for the treatment of adults with overactive bladder (OAB) in December 2020.
GEMTESA will be launched in the US late in the first quarter of 2021.
Overactive bladder (OAB) causes and symptoms
Overactive bladder (OAB) is a clinical condition that happens when the muscles of the bladder contract involuntarily. When the bladder muscle contracts too frequently or at the wrong time, the person might have signs of an OAB.
The condition is marked by a sudden need to urinate that is difficult to manage with or without accidental urinary discharge and typically with elevated urinary frequency. Unintentional urinary leakage due to urgency is referred to as UUI. Excessive urination (usually eight or more times in 24 hours) and nocturnal symptoms are some of the other symptoms of OAB.
More than 30 million people in the US suffer from troubling symptoms of OAB, which can significantly hamper the day-to-day activities of the patients.
Vibegron’s mechanism of action
Vibegron is a small molecule, selective human beta-3 adrenergic agonist that binds to and activates the beta-3 adrenergic receptor on the bladder.
Activation of the beta-3 adrenergic receptor increases the capacity of the bladder by calming the detrusor smooth muscle during the bladder filling.
The drug’s safety and efficacy in children remain unestablished.
Clinical trials on GEMTESA
FDA approval of GEMTESA was based on a 12-week, double-blind, randomised, placebo-controlled, and active-controlled clinical trial named EMPOWUR.
A total of 1,515 OAB patients were randomised in 5:5:4 ratio to receive either GEMTESA 75mg (n=545), placebo (n=540) or active control (tolterodine; n=430) orally once daily for 12 weeks.
The patients with signs of OAB for at least three months with an average of eight or more micturitions a day and at least one UUI a day, or an average of eight or more micturitions a day and at least three urgency episodes a day were eligible to enter the trial.
The study population included OAB opioid-naive patients, as well as patients who had undergone previous OAB drug therapy.
The co-primary endpoints of the trial were changes in micturition frequency and UUI episodes at week 12.
At 12 weeks, micturition reduced by an adjusted mean of 1.8 episodes a day in patients receiving GEMTESA compared to 1.3 episodes a day for placebo and 1.6 episodes a day for tolterodine.
In incontinent patients, urge incontinence episodes decreased by an adjusted mean of two episodes a day for GEMTESA versus 1.4 for placebo and 1.8 for tolterodine.
GEMTESA was also substantially superior to placebo for secondary endpoints including the number of urgency episodes, volume per urination, and proportion of incontinent patients with a 75% or higher reduction in the urge incontinence episode.
The most common adverse reactions of GEMTESA in patients during the trial were diarrhoea, nausea, headache, upper respiratory tract infection and nasopharyngitis.