To assess ofatumumab’s longer-term safety and efficacy for up to 6 years in people with relapsing multiple sclerosis (pwRMS).

Ofatumumab, a fully human anti-CD20 monoclonal antibody, demonstrated superior efficacy versus teriflunomide in the Phase 3 ASCLEPIOS I/II trials in pwRMS. Previously reported data for up to 5 years demonstrated sustained efficacy and a favorable safety profile in pwRMS.

Efficacy analyses will include all participants randomized in ASCLEPIOS I/II and their data from first dose in ASCLEPIOS I/II, whereas safety analyses will include all participants who received at least one dose of ofatumumab in either ASCLEPIOS I/II, APOLITOS, APLIOS, or ALITHIOS (cut-off date: 25-Sep-2023). Efficacy will be analyzed by the randomized treatment in the core study, with those randomized to ofatumumab referred to as continuous group and to teriflunomide as switch group.

Mean baseline age in ASCLEPIOS I/II (N=1882) was ~38 years, ~67.6% were female, and mean EDSS was ~2.9 in both groups. Previously reported 5-year data (cut-off: 25-Sep-2022) showed a sustained low annualized relapse rate (ARR) and sustained and almost complete suppression of MRI lesion activity in the continuous group. In the switch group, ARR was markedly reduced from Year 2–3 (0.16–0.06) and remained low through Years 3–5 (0.05). MRI lesion activity was almost completely suppressed through Years 3–5. At Year 5, 9 of 10 patients reached NEDA-3 in both groups. Exposure-adjusted incidence rate of adverse events (AEs), serious AEs, serious infections, and malignancies remained consistent with no increased risk over 5 years. Mean IgG levels remained stable (>lower limit of normal [LLN]: 5.65 g/L), while mean IgM levels decreased but remained >LLN (0.4 g/L). Updated 6-year efficacy and safety results will be presented at the congress.

These analyses will help inform physicians on the longer-term safety and efficacy profile of ofatumumab in pwRMS.