Study Reports Improvement in Continence With Solifenacin After Radical Prostatectomy
In a recent study, use of solifenacin was associated with a statistically significant improvement in continence in patients who underwent robotic-assisted radical prostatectomy, although no statistically significant difference in the time to return to continence. The results of this study, presented by Bianco et al in The Journal of Urology, provide level IB evidence regarding the use of antimuscarinic agents to reduce incontinence following radical prostatectomy.
Although oncologists now have a firmer grip on managing prostate cancer after radical prostatectomy, urinary incontinence remains a troublesome side effect of this surgery. Urinary incontinence can be viewed as a faulty balance between the viability and strength of the external sphincter and the impact of bladder compliance and detrusor instability. An array of clinical trials targeting urinary incontinence have provided mixed results, but recent studies evaluating solifenacin in managing urinary incontinence after radical prostatectomy have shown some promise.
Thus, the investigators conducted a large-scale trial evaluating the use of solifenacin in patients with urinary incontinence after robotic-assisted radical prostatectomy. Their targeted patients were those who continued to experience urinary incontinence 7 to 21 days after prostatectomy.
Study Details
This phase IV multicenter trial evaluated the efficacy of solifenacin compared with placebo. Men with newly diagnosed clinically localized prostate cancer who underwent radical prostatectomy were invited to participate in the study at the time of Foley catheter removal. They participated in a 7- to 21-day treatment-free screening and washout period.
Participants in the trial were first provided with a personal digital assistant (PDA) to record and transmit data about their urinary functionality. Patients were asked to complete the American Urology Association Symptom Score (AUASS) with Bother Score, the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF), and the Work Productivity and Activity Impairment Questionnaire (WPAI). Those recording on their PDA the use of 2 to 10 incontinence pads per day for 7 consecutive days and meeting the baseline criteria were eligible for the treatment phase of the trial. Patients continuing into the treatment phase were randomly assigned to receive solifenacin or placebo.
Of the 1,086 patients who went through the screening process, 623 met the requirements for the treatment phase. Of these patients, 1.6% reported preexisting urgency.
Significant Improvement Favoring Patients on Solifenacin
The investigators found a statistically significant improvement favoring patients taking solifenacin compared with patients taking placebo. The data showed that 29.1% of patients in the solifenacin group, compared with 21.4% in the placebo group, were continent at the end of the study (P = .04). Starting at week 8, a trend benefiting patients in the solifenacin group (P =.08) in the change in the number of incontinence pads used per day was seen.
Analysis of quality-of-life outcomes measures showed statistically significant improvements (P < .001) from baseline to the end of the study within both groups. A total of 44% of the patients participated in the working force prior to participating in the study. Of them, 93% of the patients receiving solifenacin and 90% of the patients receiving placebo returned to work by the conclusion of the study. There were no differences in work time missed, overall work impairment, and activity impairment.
As for adverse effects, patients receiving placebo experienced slightly fewer than those receiving solifenacin (30.3% vs 33.2%, respectively). Dry mouth was the most common adverse effect occurring in both groups. Serious adverse events were observed in five patients in the placebo group (acute coronary syndrome, cellulitis, convulsion, psoas abscess, and renal failure) and in nine patients in the solifenacin group (acute coronary syndrome, angioedema, arthritis, bladder cancer [recurrent], cholecystitis, infected lymphocele, and pulmonary embolism).
Closing Thoughts
Although the primary outcome of this study showed no statistically significant difference in the time to return to continence, there was a statistically significant improvement at the conclusion of the study associated with those patients receiving solifenacin. During the screening period, the investigators noted that approximately 40% of the patients were either using no incontinence pads or using just one pad per day.
The investigators concluded, “This study is the first prospectively randomized, placebo- controlled clinical trial that provides level IB evidence regarding the use of antimuscarinic agents to reduce incontinence following radical prostatectomy.”
Fernando J. Bianco, MD, of the Department of Urology/Erectile Dysfunction Surgery, The Surgery Center at Doral, Doral, Florida, is the corresponding author of this article in The Journal of Urology.
This study, presented at the 2014 Annual Meeting of the American Urologic Association, was funded by Astellas Pharma US. The authors reported no potential conflicts of interest.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
