Ofatumumab is a monoclonal antibody that binds to CD20 and destroys targeted B cells. B cells are among immune cells that have been implicated in causing damage to the central nervous system in MS. Ofatumumab was approved by Health Canada for the treatment of adults with relapsing-remitting MS (RRMS) with active disease defined by clinical and imaging features.
The approval was based on two identical phase 3 studies (ASCLEPIOS I and II) wherein participants were randomly assigned to receive ofatumumab (self-injected once a month), or daily oral teriflunomide for up to 30 months. Ofatumumab reduced annual relapses significantly more than teriflunomide, reduced disability worsening at three months, and reduced disease activity on MRI scans.
Ofatumumab is self-injected under the skin once monthly. The first three doses are self-injected weekly, then at week 4, switching to a once-monthly injection. The most common side-effects reported during the clinical trials include upper respiratory tract infection, headache, injection-related reactions, and local injection site reactions.
The MS Society will provide updates related to reimbursement as they become available. Individuals interested in treatment with ofatumumab are encouraged to speak with their MS healthcare team.
References:
Hauser SL, Bar-Or A, Cohen JA, Comi G, Correale J, Coyle PK, Cross AH, de Seze J, Leppert D, Montalban X, Selmaj K, Wiendl H, Kerloeguen C, Willi R, Li B, Kakarieka A, Tomic D, Goodyear A, Pingili R, Häring DA, Ramanathan K, Merschhemke M, Kappos L; ASCLEPIOS I and ASCLEPIOS II Trial Groups. Ofatumumab versus Teriflunomide in Multiple Sclerosis. N Engl J Med. 2020 Aug 6;383(6):546-557. doi: 10.1056/NEJMoa1917246. PMID: 32757523.