ORLANDO, FL USA (UroToday.com) - This presentation provided results from the Vanguard trial, a randomized double-blinded study looking at whether the use of solifenacin succinate after robotic radical prostatectomy resulted in improved urinary continence rates. It is important to note that this study was sponsored by Astellas.
Dr. Bianco discussed that the rationale behind anticholinergic use in this setting is based on prior studies demonstrating decreased bladder compliance and contractility and increased detrusor pressure on urodynamics, post-prostatectomy. After a screening phase of 2-3 weeks, those patients voiding spontaneously, but with 2 to 10 pad incontinence, were included in the study and randomized to either 5mg of solifenacin daily, or placebo. Increase of solifenacin dose to 10mg during the study was up to the discretion of the provider. The authors defined “continence” as no pad use or security pad use only, with 3 consecutive dry days. Pad use was recorded using a smartphone application which allowed for daily recordings of individual patient outcomes. The primary endpoint of the study was time to continence following randomization.
In total, 1 125 patients were screened, and of these patients 77% wore one or less pads per day by 15 weeks. After 2-3 weeks, 40% of patients had already gained continence and were excluded from the study. In total 622 patient were randomized - 309 in the placebo group and 313 in the solifenacin group. The primary endpoint of the study – time to continence – was found to not be significantly different between the two groups. However, Dr. Bianco discussed that when looking only at patients whose doses were increased to 10mg, a trend towards earlier return of continence was seen. When looking at the secondary endpoints of the study several results favored the solifenacin group. By the end of 15 week,s a higher proportion of patients in the solifenacin group reported 0-1 pad per day use compared to the placebo group (74% vs 65% respectively, p=0.01). Mean change in pad use from beginning to end of the study was higher in the solifenacin group which used 3.2 fewer pads per day compared to 2.9 fewer in the placebo group (p=0.03). Adverse effects were experienced by a third in both the placebo and solifenacin groups. Dry mouth was the most common adverse effect, experienced by 6.1% of the solifenacin group compared to 0.6% of the placebo group. No difference in rate of constipation was seen between the two groups.
Dr. Blackwell concluded that solifenacin did not demonstrate a difference with regards to improvements in time to continence, postoperatively. He stated that solifenacin does seem to help a proportion of patients regain continence post-prostatectomy, however, further work to identify those most likely to benefit is necessary. The study constitutes level IB data and represents the first multi-institutional randomized trial utilizing digital recorded patient-derived outcomes.
Presented by Fernando Bianco at the American Urological Association (AUA) Annual Meeting - May 16 - 21, 2014 - Orlando, Florida USA
Written by Timothy Ito, MD, medical writer for UroToday.com