Long-Term Open-Label Solifenacin Treatment Associated with Persistence with Therapy in Patients with Overactive Bladder Syndrome

Abstract

Objective: To examine safety and tolerability findings as primary endpoints, and efficacy outcomes as secondary endpoints, of solifenacin treatment over a period of up to 1 year. Long-term efficacy in the treatment of overactive bladder (OAB) syndrome depends in part on the patient's persistence with pharmacologic therapy. Agents with a favourable therapeutic index supporting high levels of patient satisfaction and persistence are needed. Methods: The present study was a 40-week open-label extension of two 12-week, placebo-controlled, double-blind studies of solifenacin treatment in patients with OAB. Patients who completed the 12-week studies were offered participation in the open-label extension study. All patients who entered the open-label extension study initially received solifenacin 5 mg daily for 4 weeks, after which a flexible dosing regimen allowed patients to individualise their treatment (5 mg or 10 mg) at each of the 3 study visits. Safety and tolerability assessments (the primary variable) included adverse event reporting. Efficacy data were collected from micturition diaries completed at weeks 16, 28, 40, and 52. Results: Ninety-one percent (1637/1802) of patients who completed the two 12-week randomised studies chose to participate in the long-term open-label extension study. A total of 81% of patients completed 40 weeks of open-label treatment. Solifenacin treatment was safe and well tolerated, and rates of anticholinergic side effects were relatively low. Only 4.7% of patients discontinued treatment owing to adverse events. Improvements in major symptoms of OAB were noted for all patients for up to 52 weeks of treatment. In patients randomised to solifenacin in the double-blind studies, there were small incremental improvements in all efficacy parameters (reductions in episodes per 24 hours of urgency, reductions in frequency and urge incontinence, and increases in volume voided per micturition) over the course of the extension study. Efficacy was confirmed when outcomes were assessed as a function of total solifenacin exposure. Patient satisfaction with solifenacin tolerability (85%) and efficacy (74%) were high. These results indicate that long-term treatment with solifenacin was well tolerated and associated with improvements in efficacy parameters based on patient diary data recorded over the 12-month treatment period. Moreover, the high level of patient satisfaction reported appeared to correlate well with the quantified improvements in key symptoms demonstrated in this study. Conclusions: Long-term therapy with solifenacin resulted in a favourable tolerability profile, and was associated with improvements in efficacy parameters based on diary data recorded over a 12-month period. This balance of tolerability and efficacy with solifenacin was associated with excellent persistence with therapy. These results suggest that solifenacin may be useful for the long-term treatment of the chronic symptoms associated with OAB.