Clinical and economic impact of mirabegron compared with antimuscarinics for the treatment of overactive bladder in Canada

Background: The beta(3)-adrenoceptor agonist, mirabegron, and antimuscarinic agents provide similar efficacy for the treatment of overactive bladder (OAB), but mirabegron appears to be associated with better persistence, perhaps due to an absence of anticholinergic side-effects. This study estimated the expected costs associated with the management of OAB in Canada from a societal perspective by utilizing real-world evidence. Methods: An economic model with monthly cycles and a 1-year time horizon was developed to depict a treatment pathway for a hypothetical cohort of 100 patients with OAB. At model entry, patients receive mirabegron or an antimuscarinic. Patients who do not persist may switch treatment, undergo a minimally invasive procedure, or remain symptomatic (uncontrolled). The model includes direct costs (e.g. physician visits) and indirect costs (e.g. lost productivity). A one-way univariate sensitivity analysis assessed a +/- 20% variation in each of the key model inputs. Results: At 1 year, a greater proportion of patients persisted on treatment with mirabegron compared with antimuscarinics (33% vs 15-23%), and a smaller proportion switched treatment (17% vs 20-22%). The number of healthcare visits (292 vs 299-304), pads used (74,098 vs 77,878-81,669), and work hours lost (4,497 vs 5,372-6,249) were all lower for mirabegron vs antimuscarinics. The estimated total annual cost of treatment per patient with mirabegron was $2,127.46 Canadian dollars (CAD) ($5.82 CAD/day) compared with $2,150.20-$2,496.69 CAD ($5.89-$6.84 CAD/day) for antimuscarinics. The one-way sensitivity analysis indicated the results are robust. Conclusions: Improved persistence observed in routine clinical practice with mirabegron appears to translate into benefits of reduced healthcare resource use, and lower direct and indirect costs of treatment compared with antimuscarinics. Overall, these data suggest that mirabegron may offer clinical and economic benefits for the management of patients with OAB in Canada.