Budget Impact of Aripiprazole Once Every Two Months Long-Acting Injectable for Adult Patients with Bipolar-I Disorder in the US

This study was sponsored by Otsuka Pharmaceutical Development & Commercialization Inc., Princeton, NJ, USA, and H. Lundbeck LLC, Deerfield, IL, USA. Aripiprazole, an antipsychotic with an established efficacy and safety profile, is available for managing bipolar-I disorder (BP-I) as a new ready-to-use injectable formulation (Ari2MRTU), for administration once every 2 months. Ari2MRTU provides plasma concentrations similar to aripiprazole once every month injectable formulation. A model was developed to estimate the budget impact of introducing Ari2MRTU in a hypothetical US health plan of one million members, including 21,000 (2.1%) patients with BP-I, 49% of whom were eligible for maintenance antipsychotic treatment. Inputs to the model included estimates of current and projected market share of comparator drugs, forecast uptake of Ari2MRTU, treatment acquisition, administration, and initiation costs, hospitalization (due to mood episode) costs, time on treatment, and treatment compliance. The difference in total annual costs between scenarios with and without Ari2MRTU was used to calculate the net budget impact of its introduction over a 3-year time horizon. Other outputs included cost per health plan member per month (PMPM) and per treated health plan member per month (PTMPM). The total budget impact of introducing Ari2MRTU was estimated to result in a saving of $898,930 over 3 years, with a PMPM saving of $0.025 and a PTMPM saving of $2.43. Sensitivity analysis indicated that the savings were sensitive to treatment compliance and the acquisition cost of Ari2MRTU. We concluded that the introduction of Ari2MRTU as maintenance treatment for adults with BP-I is expected to be cost neutral with respect to US payer budgets, and a potentially favorable option for patients who prefer less frequent dosing.