Abstract Details

Ofatumumab, a fully human anti-CD20 monoclonal antibody with a 20 mg subcutaneous monthly dosing regimen, demonstrated superior efficacy and similar safety versus teriflunomide in the Phase 3 ASCLEPIOS I/II overall population and in a subgroup of RDTN participants (diagnosed ≤3 years). Data from the ALITHIOS open-label extension study previously demonstrated sustained efficacy for up to 5 years in the overall and up to 4 years in the RDTN groups.

To assess ofatumumab’s longer-term efficacy for up to 6 years in people with recently diagnosed treatment-naive (RDTN) relapsing multiple sclerosis (RMS).

These analyses (data cut-off: 25-Sep-2022 [up to 5 years]/25-Sep-2023 [up to 6 years]) include cumulative data from the RDTN subgroups randomized to ofatumumab in the core (continuous group) and those originally randomized to teriflunomide and switching to ofatumumab in ALITHIOS (switch group).

The RDTN subgroup comprised 314/301 people in the continuous/switch groups (mean age at baseline: 36.8/35.7 years; 69.1%/65.8% female; mean EDSS: 2.30/2.28). In the 5-year analyses, the RDTN continuous group sustained a low annualized relapse rate (ARR) over Years 1–5 (0.1–0.01). Marked reductions in ARR in the switch group from Year 2–3 (0.1–0.053) were sustained through Years 3–5 (0.053–0.037). T2 lesion activity was suppressed in the continuous group up to Year 5, and from Year 3–5 (annualized number of new/enlarging T2 lesions: 1.29–0.043) in the switch group. In the continuous group, the odds of achieving no evidence of disease activity (NEDA-3) increased from 89% at Year 2 to 96% at Year 5, and in the switch group from 36% to 58% at Year 2–3, reaching 90% at Year 5. Six-year results will be presented at congress.

Ofatumumab demonstrates sustained long-term efficacy in people with RDTN RMS, supporting its use early in the disease course.