OBJECTIVES: To assess the budget impact of introducing the β₃-adrenergic agonist vibegron for the treatment of patients with overactive bladder (OAB) from US commercial payor and Medicare perspectives.

METHODS: A budget impact model (BIM) with 5-year time horizon was developed using a top‑down, prevalence-based approach and projected market shares for 1-million-member US commercial and Medicare plans. The BIM included vibegron, mirabegron, and anticholinergics and incorporated changes in clinical outcomes, including efficacy defined by mean daily incontinence episodes, drug-drug interactions, anticholinergic burden, OAB-related comorbidities, and adverse events (AEs). Economic outcomes are provided as costs per member per month (PMPM) and per treated member per month (PTMPM). One-way sensitivity analyses (OWSA) were performed to quantify impact in response to changes in key variables.

RESULTS: Adding vibegron to a health plan formulary was associated with a modest increase in PMPM cost over 5 years of $0.12 (range for years 1‒5, $0.01‒$0.26) for commercial payors and $0.24 (range for years 1‒5, $0.01‒$0.52) for Medicare and in PTMPM cost of $2.70 (range for years 1‒5, $0.17‒$4.85) and $3.15 (range for years 1‒5, $0.19‒$5.82), respectively. Costs were partially offset by savings related to decreased use of third-line treatments, yearly decreases in incidence of AEs and comorbidities, reduced drug-drug interactions, and reduced anticholinergic burden associated with the introduction of vibegron. OWSAs indicated that PMPM costs were most sensitive to vibegron market share assumptions, OAB prevalence, and vibegron persistence at 1 month for both private payors and Medicare and additionally vibegron persistence at 12 months for Medicare.

CONCLUSIONS: Vibegron may address an unmet need in treating OAB and may be a useful addition to health plans by improving clinical outcomes and reducing costs associated with third-line treatments, which may partially offset modest increases in pharmacy costs.