OBJECTIVES: Ofatumumab is the first fully human monoclonal anti-CD20 approved in Colombia for the treatment of adults with Relapsing-Remitting Multiple Sclerosis (RRMS) with active disease. Colombia has around 3,750 patients with RRMS, of which more than 50% where prescribed with low/moderate efficacy Disease Modifying Therapies (LME-DMT) in 2022 (Interferons, Glatiramer Acetate, Fumarates, Teriflunomide, Fingolimod). The objective of this researh was to quantify the avoided direct medical costs for the Colombian healthcare perspective by switching patients currently treated with LME-DMT to Ofatumumab.

METHODS: We used a cohort Markov model based on Expanded Disability Status Scale (EDSS). A 5-year time horizon was considered to show the avoided costs in the medium term. Each year patients could transition between EDSS states, experience a relapse or an adverse event. Baseline patients’ distribution was based on the pooled analysis of ASCLEPIOS trials. Transition probabilities were extracted from a natural history database in UK, and treatment effects on disability progression, relapses, and adverse events from published NMA. Direct costs were estimated using a micro-costing approach, considering published economic literature, the opinion of local clinical experts and national databases. To calculate the number of patients within each DMT, we used Colombian public prescription databases. We assume a switch to ofatumumab of 30% of the patients currently in LME-DMT, based on clinical experts’ opinion.

RESULTS: A switch of the 30% of the patients in LME-DMT to ofatumumab produce a 23,3% reduction in the percentage of patients experience disability progression after 5 years of treatment, 33,3% reduction in patients with at least 1 relapse, and no adverse events increasing. These clinical effects imply avoided costs of USD$249,832 and USD$942,975 (1USD=4,464COP) related to disability progression and relapses, respectively.

CONCLUSIONS: In addition to Ofatumumab’s clinical benefits for patients with RRMS, a switch from LME-DMT to Ofatumumab generates avoided costs for the Colombian healthcare system.