Abstract
Introduction: The study includes the latest findings from the MSBase Registry on the real-world Australian experience with Ofatumumab (OFA) in the treatment of relapsing multiple sclerosis (RMS). Here, we report the latest patient demographics, disease characteristics, and prior therapy history, providing valuable insights into the clinical efficacy and treatment persistence of OFA in both treatment-naive patients and those who have switched from prior therapies. Objectives/Aims: To continue to characterize the use of OFA in Australia through an evaluation of patient demographics, baseline characteristics and prior therapy of patients initiating OFA as recorded in MSBase. In addition, evaluations of clinical efficacy included annual relapse rate and estimates of time to first clinical event. Methods: This is the second analysis of a retrospective, secondary use of data study from the MSBase Registry, describing the baseline characteristics of RMS patients in Australia initiated on OFA treatment. Analyses included demographics, expanded disability status scale (EDSS) and treatment history with diseasemodifying therapies (DMTs). Kaplan Meier estimates were calculated for persistence, time to EDSS milestone and confirmed disability worsening. Results: As of 1st March 2025, MSBase has included 605 Australian patients who received at least one dose of ofatumumab, with a median age of 42.25 (35.86, 50.73) years and 76.7% female. The median disease duration was 8.75 (3.21, 16.43) years, and 22.3% of the participants were treatmentnaive. The most common previous DMTs included ocrelizumab (26.9%) and natalizumab (16.4%). The annualized relapse rate (ARR) during the follow-up period was significantly reduced to 0.05 (0.04, 0.07) compared to 0.34 (0.29, 0.40) in the year prior to starting ofatumumab (p<0.0001). Additionally, the change in EDSS from baseline indicated stable disability scores with median change 0 (-0.5, 0), 0 (-0.5, 0.5) and 0 (-0.5, 0.5) at 12, 18 and 24 months respectively. Kaplan Meier estimates calculated treatment persistence at 96.6% [0.9441, 0.9795] at one year and 93.3% [0.8999, 0.9553] at two years follow-up. Conclusion: The second analysis of the real-world data from the MSBase registry provides further insight into the Australian experience of relapsing MS patients initiated on OFA, with a high treatment persistence and stable disability over 24 months on treatment.