Cost-effectiveness of aripiprazole once-monthly compared with paliperidone palmitate once-monthly injectable for the treatment of schizophrenia in the United States

Abstract

Objective: To develop a decision-analytic model to estimate the cost-effectiveness of initiating maintenance treatment with aripiprazole once-monthly (AOM) vs paliperidone long-acting injectable (PLAI) once-monthly among patients with schizophrenia in the US.

Methods: A decision-analytic model was developed to evaluate a hypothetical cohort of patients initiating maintenance treatment with AOM or PLAI. Rates of relapse, adverse events (AEs), and direct medical costs were estimated for 1 year. Patients either remained on initial treatment or discontinued treatment due to lack of efficacy, AEs, or other reasons, including non-adherence. Data from placebo-controlled pivotal trials and product prescribing information (PI) were used to estimate treatment efficacy and AEs. Analyses were performed assuming dosing of clinical trials, real-world practice, PIs, and highest therapeutic dose available, because of variation in practice settings. The main outcome of interest was incremental cost per schizophrenia hospitalization averted with AOM vs PLAI.

Results: Based on placebo-controlled pivotal trials' dosing, AOM improved clinical outcomes by reducing schizophrenia relapses vs PLAI (0.181 vs 0.277 per person per year [pppy]) at an additional cost of US$1276 pppy, resulting in an incremental cost-effectiveness ratio (ICER) of US$13,280/relapse averted. When PI dosing was assumed, this ICER increased to US$19,968/relapse averted. When real-world dosing and highest available dosing were assumed, AOM was associated with fewer relapses and lower overall treatment costs vs PLAI.

Conclusions: AOM consistently provided favorable clinical benefits. Under various dosing scenarios, AOM results indicated fewer relapses at lower overall costs or a reasonable cost-effectiveness threshold (i.e., less than the cost of a hospitalization relapse) vs PLAI. Given the heterogeneous nature of schizophrenia and variability in treatment response, health plans may consider open access for treatments like AOM. Since model inputs were based on data from separate placebo-controlled trials, generalization of results to the real-world setting is limited.

Keywords: Aripiprazole once-monthly; Cost-effectiveness; Long-acting injectable; Paliperidone palmitate.