OBJECTIVES: To conduct a cost-effectiveness analysis of two FDA-approved vesicular monoamine transporter 2 (VMAT2) inhibitors, valbenazine and deutetrabenazine, for treating the symptoms of moderate-to-severe tardive dyskinesia (TD) compared to placebo in adult patients with underlying schizophrenia/schizoaffective, bipolar, and major depressive disorders in the United States.
METHODS: A new semi-Markov model with time-dependent mortality and TD medication discontinuation rates was developed, employing annual cycles over a lifetime horizon. The base-case model included four health states: improved TD, moderate to severe TD, discontinued therapy with improved TD, and death. Treatment outcomes, utility, and cost inputs were obtained through systematic literature reviews, grey literature, and when necessary, consensus-based assumptions, with input from clinical experts and manufacturers. The model base-case was built from a health system perspective. The primary model outcomes included total payer costs and quality-adjusted life years (QALYs) gained (each discounted at 3% per year), combined to generate incremental cost/QALY gained. One-way, two-way, and probabilistic sensitivity analyses were conducted to evaluate model uncertainty.
RESULTS: Discounted lifetime costs for valbenazine and the placebo comparator were approximately $185,200 and $6,900 and discounted QALYs for valbenazine and placebo were 15.35 and 15.12, respectively. Deutetrabenazine and its placebo comparator had lifetime discounted costs of approximately $220,000 and $6,600 and lifetime discounted QALYs of 15.37 and 15.18, respectively. The incremental cost-effectiveness ratios over a lifetime horizon were approximately $750,000 per QALY for valbenazine and $1.1 million per QALY for deutetrabenazine. When model inputs were varied across reasonable ranges in one-way sensitivity analyses, none resulted in estimates approaching thresholds of $150,000 per QALY. Further, the probabilistic sensitivity analyses resulted in acceptability curves with an extremely low likelihood that the treatments will reach these thresholds.
CONCLUSIONS: In base-case and sensitivity analyses, the incremental cost effectiveness ratios for valbenazine and deutetrabenazine versus placebo far exceeded commonly utilized cost-effectiveness thresholds.
