Cost-effectiveness of mirabegron compared to tolterodine ER 4 mg for overactive bladder in Canada

Abstract

Introduction: This analysis compared the cost-effectiveness of once-daily regimens of mirabegron 50 mg and generic tolterodine ER 4 mg in a hypothetical cohort of previously treated patients with overactive bladder (OAB) in Canada. Methods: A Markov model was developed to represent different health states according to OAB symptoms (frequency, incontinence), presence/absence of adverse events (AEs; dry mouth, constipation, blurred vision), and treatment status (on-treatment, discontinue treatment, restart previous treatment). The time horizon used was one year, with monthly transitions between health states. The model was populated using data from a phase 3, placebo-controlled trial of mirabegron that included tolterodine as an active comparator (SCORPIO), as well as other published literature and expert opinion. Cost-effectiveness was calculated from Canadian public payer (based on Quebec list prices) and societal perspectives. Results: The incremental one-year cost per patient for mirabegron over tolterodine was $182 CAD and $157 CAD from the payer and societal perspectives, respectively. The incremental quality-adjusted life year (QALY) gain for mirabegron was 0.0066 when using EQ-5D health-state utilities. Mirabegron was cost-effective compared with tolterodine, from both payer and societal perspectives, and remained cost-effective vs. tolterodine across the majority of sensitivity analyses. The model was based on limited clinical trial evidence supplemented with expert opinion and assumptions; a select number of OAB symptoms, AEs, and direct and indirect medical costs associated with OAB; and a timeframe of only one year. Conclusions: From the payer and societal perspectives, the health economic model indicates that in Canada, mirabegron is a cost-effective treatment strategy compared with tolterodine, leading to improved health outcomes (QALYs) at an acceptable incremental cost.