Botulinum Toxin Beats Neuromodulation for Overactive Bladder

Kate Johnson

May 11, 2016

SAN DIEGO — For women with refractory urgency urinary incontinence, symptom control is better with injected onabotulinum toxin A (Botox) than with sacral neuromodulation, according to results from the ROSETTA trial.

"A lot of people are excited to see these results; it's a very important, very relevant trial," said Victor Nitti, MD, from the NYU Langone Medical Center in New York City, who is a spokesperson for the American Urological Association (AUA). "And even though the study was only in women, I think the findings will be at least somewhat generalizable to men."

Although urinary tract infection and the need for transient self-catheterization are more common with the injection than with neuromodulation, the adverse-effect profile of onabotulinum toxin A is "very reasonable," Dr Nitti told Medscape Medical News.

Results from ROSETTA — Refractory Overactive Bladder: Sacral Neuromodulation vs Botulinum Toxin Assessment — were presented here at the AUA 2016 Annual Meeting by researcher Cindy Amundsen, MD, from the Duke University Medical Center in Durham, North Carolina.

Dr Amundsen and her colleagues randomized 386 women with at least six urgent urinary incontinence episodes per day to either onabotulinum toxin A injection or sacral neuromodulation.

Mean age in the study cohort was approximately 63 years, and mean body mass index was approximately 32 m/kg². More than 80% of both treatment groups rated themselves as "severely or very severely incontinent on the Sandvik questionnaire," Dr Amundsen reported.

In the injection group, onabotulinum toxin A 200 U was injected into the bladder detrusor smooth muscle.

In the neuromodulation group, the women underwent a two-stage procedure. First, an electrode was placed through the sacral foramen along a sacral nerve (usually S3) and attached to an external test stimulator. After stimulation was demonstrated to be successful, the lead was connected to an implanted pulse generator (InterStim, Medtronic).

The rate of clinical response — defined as a reduction of at least 50% in urgent urinary incontinence episodes on a 3-day bladder diary — was similar in the injection and neuromodulation groups (83% vs 84%). This was measured at 1 month in the injection group and during the test phase in the neuromodulation group.

In the intention-to-treat analysis at 6 months, the change in the mean number of daily incontinence episodes from baseline — the primary outcome — was greater in the injection group than in the neuromodulation group (–3.9 vs –3.3 episodes/day; P = .01).

Similarly, more patients in the injection group than in the neuromodulation group achieved complete symptom resolution at 6 months (20% vs 4%; P < .0001) and a reduction of at least 75% in episodes per day (46% vs 26%; P = .0002).

Overactive bladder symptom bother scores, measured with the Overactive Bladder Questionnaire Short Form, were significantly better in both groups after treatment, but the change from baseline was greater in the injection group than in the neuromodulation group (–46.71 vs –38.5; P = .002).

Treatment satisfaction was better in the injection group than in the neuromodulation group (P = .01), as was endorsement, assessed with the Overactive Bladder Satisfaction of Treatment Questionnaire (P = .0009).

Adverse Events

At 6 months, the rate of urinary tract infection was higher in the injection group than in the neuromodulation group (35% vs 11%; P < .0001).

In addition, in the injection group, intermittent catheterization was required by 8% of patients at 1 month, by 4% at 3 months, and by 2% at 6 months. In the neuromodulation group, 3% of patients required surgical revision or removal.

Onabotulinum toxin A injection and sacral neuromodulation are both third-line therapies for overactive bladder, to be used after therapies such as behavior modification, pelvic floor exercises, and medication, said Dr Nitti.

"There's really been no clear-cut guidance on whether you should do one or the other," he explained.

The only drawback of this study is that it used a 200 U dose of onabotulinum toxin A, he noted.

"The FDA-approved dose is 100 U," he pointed out. "We know [onabotulinum toxin A] is more effective at a higher dose, but the problem is it has more side effects, the main one being that patients can't empty their bladders and need to catheterize."

In this study, however, rates of catheterization "were much lower than in other studies of 200 U," he reported. "I can't explain that."

Dr Amundsen and Dr Nitti have disclosed no relevant financial relationships.

American Urological Association (AUA) 2016 Annual Meeting: Abstract 1135. Presented May 9, 2016.

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