The Food and Drug Administration (FDA) has approved Myrbetriq® (mirabegron extended-release tablets) and Myrbetriq® Granules (mirabegron for extended-release oral suspension) for the treatment of neurogenic detrusor overactivity (NDO) in pediatric patients. Both formulations are indicated for patients aged 3 years and older; however, the tablet formulation is specifically approved for patients weighing 35kg or more.
NDO is a neurological bladder dysfunction commonly observed in children with spina bifida that leads to symptoms of urinary urgency, frequency and incontinence. The approval was based on data from a phase 3, open-label study (ClinicalTrials.gov: NCT02751931) that included 91 patients 3 to 17 years of age with NDO on clean intermittent catheterization.
Results showed that treatment with mirabegron led to improvements in maximum cystometric capacity at week 24 (primary endpoint). Improvements were also observed on several secondary endpoints, including the number of overactive detrusor contractions, volume of urine held until first detrusor contraction, and number of daily urine leakage episodes.
As for safety, the most commonly reported adverse reactions with mirabegron in pediatric patients with NDO included UTI, nasopharyngitis, constipation, and headache. Blood pressure increases have also been associated with mirabegron treatment and may be larger in children than in adolescents.
The extended-release tablet is supplied in 25- and 50mg strengths and is currently available. Myrbetriq Granules, which contains 8mg/mL of mirabegron following reconstitution, is expected to be available by the end of 2021.
1. FDA Approves New indication for Drug to Treat Neurogenic Detrusor Overactivity in Pediatric Patients. [press release]. Silver Spring, MD: U.S. Food and Drug Administration; March 25, 2021.
2. Myrbetriq® [package insert]. Northbrook, IL: Astellas Pharma; 2021.