Efficacy and safety of combinations of mirabegron and solifenacin compared with monotherapy and placebo in patients with overactive bladder (SYNERGY study).

In the largest OAB study to date, combined therapy with solifenacin 5 mg + mirabegron 25 mg and solifenacin 5 mg + mirabegron 50 mg provided consistent improvements in efficacy compared with the respective monotherapies across most of the outcome parameters, with effect sizes generally consistent with an additive effect. Although the combined S5 + M50 group did not achieve a statistically significant effect vs mirabegron 50 mg in the primary analysis of one of the co-primary endpoints (change from baseline in mean number of UI episodes/24 h), it approached statistical significance (P = 0.052), and the nominal P values for the other co-primary endpoint (micturitions/24 h) were <0.05. Most effects of combined therapy vs monotherapy were observable by week 4. The clinical relevance of the improvements seen with combined therapy for several objective OAB outcome measures was also supported by the improvements of combined therapy vs monotherapy in the responder analyses.