OBJECTIVES : Myasthenia gravis (MG) is a rare chronic autoimmune neuromuscular disorder, which causes debilitating and potentially life-threatening exacerbations of muscle weakness. The objective of this study was to develop a novel United States (US) budget impact analysis framework to assess innovative MG treatments.

METHODS : A targeted literature review was conducted to identify previous economic evaluations of MG. Clinical experts were consulted to ensure model components reflected current clinical practice and understanding. US payers were engaged to provide feedback on the structure and outputs, and how to optimize the utility of the model framework for informing formulary decision-making.

RESULTS : Few US economic analyses of MG treatments were identified in the literature. Recent data on direct pharmacy and medical costs were sparse. A novel model framework was developed for assessing the budget impact of an innovative MG therapy, which includes treatment-related costs and medical costs offsets. Modeled costs in the framework include direct pharmacy and medical costs of chronic MG treatments, chronic therapy adverse effects, MG exacerbations and myasthenic crisis events. Myasthenia gravis exacerbations and crisis costs include acute inpatient, emergency department and outpatient care as well as temporary treatment with immunoglobulin or plasma exchange following MG exacerbations. Clinical experts recommended that treatment comparators should include all combinations of conventional and add-on therapies to reflect the individualized treatment pathways observed in practice. Conventional therapies include combinations of corticosteroids, non-steroidal immunosuppressive drugs (e.g. azathioprine, mycophenolate mofetil) and acetylcholinesterase inhibitors. US payers recommended flexibility to adapt treatment market shares and time horizons to conduct alternative scenario analyses.

CONCLUSIONS : Future budget impact analysis for MG treatments should capture both direct pharmacy and medical costs including those related to disease exacerbations and treatment adverse effects. The framework includes all the identified core components essential to assessing the full budget impact of novel MG treatments on direct pharmacy and medical costs.