Inebilizumab for neuromyelitis optica spectrum disorders in Italy: a budget impact model.

Background: The Italian National Health Service (INHS) has recently reimbursed the monoclonal antibody inebilizumab as a second line monotherapy after rituximab (RTX) use for neuromyelitis optica spectrum disorders (NMOSD) patients ≥ 18 years anti-aquaporin 4 antibody-immunoglobulin G positive, who experienced a relapse in the last year or cannot receive RTX, if incident patients. Other INHS-reimbursed drugs for NMOSD treatment are satralizumab, eculizumab and, off-label, besides RTX, ocrelizumab, tocilizumab, and immunosuppressants.

Research Design And Methods: A 3-year (2023-2025) prevalence-based budget impact model following the INHS viewpoint compared the costs and the NMOSD attacks without (1st scenario) and with inebilizumab (2nd scenario). The epidemiology of NMOSD, and the INHS-funded healthcare resources (drugs and their administration; specialist visits; hospitalizations due to drug-related adverse events and NMOSD attacks) were obtained from the literature. One-way, threshold value and scenario sensitivity analyses investigated the robustness of the baseline findings.

Results: During 2023-2025 inebilizumab saves the INHS €8,373,125.13 (1st scenario: €176,770,028.63; 2nd scenario: €168,396,903.50) and 12.74 NMOSD attacks (1st scenario: 213.94; 2nd scenario: 201.19). Sensitivity analyses confirmed the robustness of the baseline results.

Conclusion: Inebilizumab reduces the INHS expenditure for NMOSD drugs. Future research should explore the cost-effectiveness of inebilizumab vs other NMOSD-targeting drugs in Italy.