BACKGROUND: This study compared the efficacy and tolerability of solifenacin in patients with overactive bladder (OAB) who had previously been dissatisfied with tolterodine tartrate extended release (tolterodine ER 4 mg) and had residual urgency symptoms as determined on a 3-day micturition diary.
METHODS: VERSUS (VESIcare^® Efficacy and Research Study US) was an open-label, flexible-dosing, multicenter study designed to assess the efficacy and safety of daily oral solifenacin. Patients (n = 441) were enrolled who were currently receiving tolterodine ER 4 mg for 4 weeks or longer (median length of previous therapy = 190 days) but remained dissatisfied and had residual urgency symptoms (defined as ≥ 3 urgency episodes per 24 hours reported in the screening 3-day diary). Tolterodine ER 4 mg therapy was stopped 5-7 days after screening. Following a washout period of approximately 14 days, all patients were started on 5 mg solifenacin per day. Patients could maintain or increase their dose to 10 mg per day at Week 4, and maintain or decrease to 5 mg at Week 8. Improvements in urgency, urge incontinence, frequency, nocturia, and nocturnal voids, as recorded in micturition diaries at multiple study visits, were compared to Pre-Washout (during tolterodine ER 4 mg treatment) and Post-Washout values.
RESULTS: The mean change in the number of urgency episodes per 24 hours (primary endpoint) was reduced by 3.41 from Pre-Washout to Week 12 of solifenacin treatment (P<0.0001). Micturitions, incontinence episodes, nocturia episodes, and nocturnal voids were reduced by 1.57, 1.86, 0.72, and 0.79, respectively (P<0.0001). Improvements in OAB symptoms were observed within the first 7 days of solifenacin treatment as measured by a 7-day diary. Treatment-emergent adverse events were mostly anticholinergic in nature, of mild or moderate intensity, and few patients discontinued treatment owing to adverse events (17/441; 3.9%).
CONCLUSIONS: Patients who were dissatisfied with tolterodine ER 4 mg treatment after 4 weeks and had residual OAB symptoms (urgency) may benefit from flexibly-dosed solifenacin treatment. In these patients, solifenacin was efficacious and well tolerated in improving diary-evaluated OAB symptoms.
Figure. Changes in OAB Symptoms Following Solifenacin Treatment at Week 12 vs Pre-Washout and Post-Washout Baseline Values