Only a few weeks prior to MSVirtual2020, the fully human anti-CD20 monoclonal antibody ofatumumab was approved by the FDA for the treatment of relapsing MS. In the open-label extension study ALITHIOS, ofatumumab’s safety profile was shown to be consistent with data from the core phase 3 ASCLEPIOS I/II trials.

The indication of ofatumumab is to include clinically isolated syndrome (CIS), relapsing-remitting disease (RRMS), as well as active secondary progressive MS (SPMS) in adults. In the ASCLEPIOS trials, ofatumumab demonstrated superior efficacy versus teriflunomide and a favourable safety profile in relapsing MS patients [1]. Long-term safety data continues to be collected from the open-label phase 3b ALITHIOS extension study. The overall safety data of all patients in ALITHIOS were reported [2].

Participants included the continuous group of patients (n=1,230) who were randomised to ofatumumab in the core phase 2 APLIOS (12 weeks) or phase 3 ASCLEPIOS I/II (up to 30 months) trials and continued in ALITHIOS, or completed/discontinued the core study and continued the safety follow-up; as well as the newly switched group of patients (n=643) who were randomised to teriflunomide in ASCLEPIOS I/II and switched to ofatumumab in ALITHIOS. The overall exposure was 2,118 patient-years.

The most frequently reported adverse events (AEs) in ALITHIOS were injection-related reactions and upper respiratory tract infections. Most reported AEs were mild to moderate in severity; in neither group did the incidences of AEs, serious AEs, or grade 3/4 AEs increase. The overall safety profile was consistent with reports from the core ASCLEPIOS I/II trials. There were no deaths. In the newly switched group, injection-related reactions were mild to moderate; none were serious or led to treatment discontinuation. With regard to AEs of special interest, there were no opportunistic infections, hepatitis B reactivation, or progressive multifocal leukoencephalopathy (PML) events. Also, there were no new cases of malignancies in either the continuous or newly switched patients.


  1. Hauser SL, et al. N Engl J Med. 2020;383:546–57.
  2. Cross AH, et al. MSVIRTUAL2020, Abstract P0234.