Randomized, double‐blind placebo‐ and tolterodine‐controlled trial of the once‐daily antimuscarinic agent solifenacin in patients with symptomatic overactive bladder

Abstract

An international, multicentre, randomized double‐blind trial is presented. Patients were randomized to treatment with tolterodine, placebo, and two doses of solifenacin. The authors concluded that the two doses of solifenacin improved urgency and other symptoms of the overactive bladder, with an acceptable level of side‐effects. A further phase 3 study into the effect of duloxetine was undertaken to assess whether the previous evidence of efficacy from North America and Europe could be sustained in other parts of the world. In this double‐blind placebo‐controlled study, the authors found that duloxetine improved continence and quality of life, in keeping with the findings in North America and Europe. A novel temporary prostatic stent has been evaluated; it looks like the proximal 4‐6 cm of a Foley catheter, with a similar proximal balloon to prevent displacement. In this early study it was found to be user‐friendly, and to improve symptoms in patients with BOO caused by prostatic enlargement. OBJECTIVE To assess in a phase 3a trial the efficacy of solifenacin succinate, a once‐daily oral antimuscarinic agent in development at 5‐mg and 10‐mg dosage strengths, for the treatment of overactive bladder (OAB)) (Yamanouchi Pharmaceutical Co. Ltd, Tokyo, Japan) compared with placebo in patients with symptoms of OAB, i.e. urgency, incontinence, and frequency, with additional objectives being to assess the safety and tolerability of solifenacin and to compare the efficacy and safety of solifenacin with tolterodine 2 mg twice daily. PATIENTS AND METHODS The study was an international, multicentre, randomized, double‐blind, tolterodine‐ and placebo‐controlled trial conducted at 98 centres. Adult patients with symptomatic OAB for ≥ 3 months were eligible; after a single‐blind 2‐week placebo run‐in period patients were randomized equally to a 12‐week double‐blind treatment with either tolterodine 2 mg twice daily, placebo, solifenacin 5 mg or 10 mg once daily. Efficacy variables included change from baseline in the mean number of urgency, incontinence and urge incontinence episodes, and change from baseline in voids/24 h and mean volume voided/void. RESULTS In all, 1281 patients were enrolled, 1081 randomized and 1077 treated; 1033 were evaluated for efficacy. Compared with placebo, the change from baseline (−1.41, −32.7%) in the mean number of urgency episodes per 24 h was statistically significantly lower with solifenacin 5 mg (−2.85, −51.9%) and 10 mg (−3.07, −54.7%; both P < 0.001), but not with tolterodine (−2.05, −37.9%; P = 0.0511). There was a statistically insignificant decrease in episodes of incontinence with tolterodine (−1.14; P = 0.1122) but a significant decrease in patients treated with solifenacin 5 (−1.42; P = 0.008) and 10 mg (−1.45; P = 0.0038). Compared with placebo (−1.20, −8.1%) the mean number of voids/24 h was significantly lower in patients receiving tolterodine (−1.88, −15%; P = 0.0145), solifenacin 5 (−2.19, −17%) and 10 mg (−2.61, −20%; both P < 0.001). The mean volume voided/void was also significantly higher with all three active treatments (P < 0.001). Solifenacin was well tolerated; compared with placebo (4.9%), dry mouth (the most common side‐effect), mostly mild, was reported in 18.6% of patients receiving tolterodine, 14.0% receiving 5 mg and 21.3% receiving 10 mg solifenacin. CONCLUSION Solifenacin 5 and 10 mg once daily improved urgency and other symptoms of OAB, and was associated with an acceptable level of anticholinergic side‐effects. Solifenacin demonstrated significantly favourable efficacy to side‐effect ratio in treating symptomatic OAB.