Cost-effectiveness analysis of ocrelizumab versus subcutaneous interferon beta-1a for the treatment of relapsing multiple sclerosis

Aim: To conduct a cost-effectiveness analysis to compare ocrelizumab vs subcutaneous (SC) interferon beta-1a for the treatment of relapsing multiple sclerosis (RMS). Methods: A Markov cohort model with a 20-year horizon was developed to compare ocrelizumab with SC interferon beta-1a from a US payer perspective. A cohort of patients with relapsing-remitting MS (RRMS) and Expanded Disability Status Scale (EDSS) scores of 0-6, who initiated treatment with ocrelizumab or SC interferon beta-1a, were entered into the model. The model considered 21 health states: EDSS 0-9 in RRMS, EDSS 0-9 in secondary-progressive multiple sclerosis (SPMS), and death. Patients with RRMS could transition across EDSS scores, progress to SPMS, experience relapses, or die. Transition probabilities within RRMS while patients received ocrelizumab or SC interferon beta-1a were based on data from the two SC interferon beta-1a-controlled Phase III OPERA I and OPERA II trials of ocrelizumab in RMS. Transitions within RRMS when off-treatment, RRMS-to-SPMS transitions, transitions within SPMS, and transitions to death were based on the literature. Utilities of health states, disutilities of relapses, costs of therapies, and medical costs associated with health states, relapse, and adverse events were from the literature and publicly available data sources. The model estimated per-patient total costs, incremental cost per life year (LY) gained, and incremental cost per quality-adjusted LY (QALY) gained. Deterministic sensitivity analyses (DSA) and probabilistic sensitivity analysis (PSA) were conducted to evaluate the robustness of the model results. Results: Ocrelizumab was associated with a cost savings of $63,822 and longer LYs (Delta = 0.046) and QALYs (Delta = 0.556) over a 20-year time horizon. The results of the model were robust in the DSA and PSA. Limitations: The model did not consider subsequent treatments and their impact on disease progression. Conclusions: The results suggest that ocrelizumab is more cost-effective than SC interferon beta-1a for the treatment of RMS.