Cost-Effectiveness of Ofatumumab Versus Ocrelizumab in Patients With Active Relapsing Multiple Sclerosis in Portugal

OBJECTIVES: Ofatumumab is an antibody against a protein called CD20, which is found on the surface of certain types of immune cells called B-cells, that was approved to treat relapsing Multiple Sclerosis (MS) in adults with active disease. Our objective was to estimate the cost effectiveness of ofatumumab versus ocrelizumab in adult patients with active disease, defined by clinical or imaging characteristics, without prior treatment (naïve patients, 1^st line).

METHODS: A 1-year cycle cohort-based Markov state transition model was developed to simulate disease progression, measured by Kurtzke Expanded Disability Status Scale (EDSS). Patients were assumed to remain on treatment until progression to EDSS level 7. Natural history was based on British Columbia Multiple Sclerosis registry and London Ontario database. Efficacy, safety, and health-state utility values were estimated from the ASCLEPIOS I and II trials. No direct comparison between ofatumumab and ocrelizumab was available, therefore efficacy and safety results between these treatment options were estimated trough network meta-analysis. Resource consumption by EDSS and due to relapses was based on published literature, National DRG microdata and expert opinion. Unit costs were obtained from official sources. The analysis was conducted from payers' perspective, assuming a time horizon of 60 years and discount rate of 4%. Uncertainty was assessed trough probabilistic and deterministic sensitivity analyses.

RESULTS: Compared to ocrelizumab, ofatumumab was associated with a delay in progression, resulting in a gain of 0.15 quality adjusted life years (QALYs) and a cost decrease of 35,182€. Probabilistic sensitivity analysis resulted was dominant in 97% of the simulations.

CONCLUSIONS: Treatment of Relapsing Remitting Multiple Sclerosis with ofatumumab was less costly and more effective than treatment with ocrelizumab. Hence, this is a dominant strategy in the Portuguese setting.