NEW ORLEANS – Regular injections of onabotulinumtoxinA significantly decreased urinary incontinence in patients with neurogenic detrusor bladder overactivity over 4 years of follow-up in 4-year extension study results of a randomized trial.
Incontinence episodes decreased from an average of four per day to one or less after each treatment, Dr. Eric Rovner said at the annual meeting of the American Urological Association.
Each treatment was effective for about 9 months, and the benefit consistent throughout the 4-year study, said Dr. Rovner of the Medical University of South Carolina, Charleston.
About 90% of patients had at least a 50% reduction in incontinence episodes, and more than half experienced a complete cessation of incontinence.
OnabotulinumtoxinA (Botox) was approved in 2011 as a treatment for neurogenic urinary incontinence. Each treatment consists of 20 injections delivered cystoscopically.
Dr. Rovner reported a post hoc analysis of 227 patients who completed 4 years of treatment – a 1-year placebo-controlled trial, and 3 years of open-label extension with a dosage of 200 units of onabotulinumtoxinA.
Patients were relatively young (mean 45 years); about half were male. Most (53%) had multiple sclerosis. The remainder had a spinal cord injury that affected bladder function. Half were taking an anticholinergic medication, but had not responded to it.
Most patients (71%) were already performing intermittent catheterization. Despite that, they had a mean of four incontinence episodes each day.
Over the entire 4 years, onabotulinumtoxinA was associated with significant and consistent improvements in incontinence, with a mean decrease of up to 3.8 incidents per day each year. Each year, about 90% experienced at least a 50% improvement. About half experienced a complete cessation of incontinence over the period.
Urinary tract infections occurred in 20% of patients in years 1 and 2, and 18% in years 3 and 4, which was not significantly different. Urinary retention was highest in year 1 (12%) and dropped to 2% by years 3 and 4.
In the first year, 39% of those who didn’t need intermittent catheterization at baseline had to begin doing so. By year 2, the de novo catheterization rate was 11%. It was 8% in year 3, and in year 4, there were no new catheterizations.
These changes were not only statistically significant, but clinically important, Dr. Rovner said. On a secondary measure, the Incontinence Quality of Life Questionnaire (I-QOL), patients experienced a mean increase of more than 30 points over each study year. An 11-point change is usually considered clinically meaningful, he said.
“This was making a big difference for these patients.”
Dr. Rovner disclosed relationships with Allergan and a number of other pharmaceutical and medical device companies.
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