Studies Expand Evidence for Mirabegron in Children with Spina Bifida

Research By: Brian A. VanderBrink, MD | Michael R. Daugherty, MD, MHI

Post Date: July 7, 2026 | Publish Date:

A healthcare provider reviews treatment options with a caregiver and young child during a pediatric urology clinic visit. The child holds a pen while looking toward a clipboard or tablet presented by the provider. The image illustrates a conversation about care planning and medical management in a bright outpatient healthcare setting.

Cincinnati Children’s researchers examine whether a beta-3 agonist can improve bladder function, reduce side effects and expand treatment options for children with neurogenic bladder

In children with spina bifida, neurogenic bladder can lead to elevated bladder pressures that threaten long-term kidney function.

Physicians have long used antimuscarinic medications, often combined with clean intermittent catheterization, to relax the bladder and lower those pressures. But some children continue to have unsafe bladder dynamics despite treatment, and antimuscarinics can cause significant side effects. For those patients, the next steps may include surgical procedures such as Botox injections or bladder augmentation.

A multi-institutional research team wanted to know whether adding mirabegron, a beta-3 agonist that relaxes the bladder through a different mechanism, could provide another option and minimize the need for surgical intervention.

“For a lot of these patients, I think the goals are looking at more of the pressure improvement than the continence,” says Michael Daugherty, MD, a pediatric urologist at Cincinnati Children’s. “The focus is on making the bladder safer so it doesn’t deteriorate kidney health.”

Improvement Even in High-Risk Bladders

In a retrospective study, published in October 2025 in the Journal of Pediatric Urology, researchers reviewed records from 103 patients with spina bifida who had been taking an antimuscarinic but continued to have unsafe bladder findings or persistent incontinence. In clinical care, physicians had added mirabegron to the patients’ existing therapy. The researchers compared urodynamic test results before and after combination treatment.

Across the group, combination therapy significantly lowered bladder pressure both when filling began and at the end of bladder filling (end-fill detrusor pressure). Among the 56 patients classified as having high-risk bladders, bladder capacity increased from a median of 108.2 mL to 230.1 mL, while pressure at the end of filling fell from 51 to 32 cm H₂O. Pressure at the start of filling also decreased significantly.

The response in that high-risk group was especially encouraging, Daugherty says, because uncontrolled bladder pressures put these children at the greatest risk for kidney damage.

Continence improved as well. Of 95 patients with urinary incontinence at baseline, 79 improved or resolved after adding mirabegron.

The study also gave researchers published data to support a treatment approach that Cincinnati Children’s and Children’s Hospital of Philadelphia clinicians had already begun using based on their clinical experience.

Extending the Research to Children Under 3

A second Cincinnati Children’s study, published online July 2, 2026, in the Journal of Pediatric Urology, extends the research to children younger than 3. Mirabegron is FDA-approved for pediatric patients age 3 and older, creating a treatment challenge for younger children who may benefit from it as an alternative or addition to antimuscarinic therapy.

This retrospective study included 19 children with spina bifida who had received mirabegron as primary therapy as an alternative to antimuscarinics or in combination with an antimuscarinic. All 10 children who switched because of antimuscarinic side effects experienced resolution of those effects.

“The medication was well tolerated without adverse effects, and measured bladder metrics improved in all but one of the patients exposed to mirabegron,” says Brian VanderBrink, MD, a pediatric urologist at Cincinnati Children’s. “The once-daily dosing was preferable to the multiple-dose schedule of antimuscarinics.”

VanderBrink says continuing to build evidence is important because mirabegron is newer and insurance coverage can be difficult, particularly outside its FDA-approved age range.

Taken together, the studies are adding evidence for more flexible use of mirabegron in children with spina bifida. Researchers are particularly interested in whether combination medical therapy can help some children with high-risk bladders postpone or avoid surgery.

“Less surgery can minimize exposure to anesthesia and surgical complications in these select patients,” VanderBrink says.

ABOUT THE STUDIES

The 2025 study included researchers from Cincinnati Children’s, Children’s Hospital of Philadelphia and Einstein Healthcare Network. The 2026 study was conducted at Cincinnati Children’s. Neither study received external funding.