Effectiveness and safety of ofatumumab in treatment-naive and oral DMT-switched multiple sclerosis patients: a multicenter observational study in China.

Ofatumumab, a fully humanized anti-CD20 antibody, reduced disease activity and disability progression in Chinese patients with relapsing multiple sclerosis. Among 38 treatment-naïve patients, the annualized relapse rate fell from 0.27 to 0.05, and the median disability score dropped from 2.50 to 2.00 after 12 months. Among 59 patients who switched from oral therapies (teriflunomide, siponimod, fingolimod, dimethyl fumarate) due to disease progression, relapse, or MRI activity, the relapse rate decreased from 0.45 to 0.08 and disability scores improved from 2.00 to 1.00. No new MRI lesions, relapses, or serious adverse events occurred in either group.

Study at a glance

Abstract

Ofatumumab, a fully humanized anti-CD20 monoclonal antibody, is the only highly effective disease modifying therapy (DMT) approved for the treatment of relapsing multiple sclerosis (RMS) in China up to data. Real-world data are necessary to investigate the factors for switching from oral DMTs and to assess the effectiveness and safety of ofatumumab in the Chinese MS population. We conducted a multicenter observational study (GY2024-038-0) to evaluate the effectiveness and safety of ofatumumab in RMS patients who were either treatment-naïve or had switched from oral DMTs, including teriflunomide, siponimod, fingolimod, dimethyl fumarate. Medical records at three tertiary hospitals were collected between December 2021 and May 2024. Clinical relapses, MRI activity, confirmed disease progression, and adverse events were reviewed. Treatment-naïve and switched data were obtained for 38 (31.5 % men, mean age 35.42 years, median disease duration 2.31±4.08 years, median follow-up 12.00 months) and 59 (16.9 % men, mean age 34.75 years, median disease duration 5.30±4.17 years, median follow-up 20.00 months) patients, respectively. Among treatment-naïve patients, the annualized relapse rate (ARR) at the final follow-up decreased from 0.27 ± 0.47 to 0.05 ± 0.23 (p < 0.001), while the Expanded Disability Status Scale (EDSS) score at month 12 after treatment dropped from 2.50(2.00-4.00) to 2.00(1.00-3.00) (p < 0.001). For patients switched from oral DMT, the mean reasons for transitioning were disease progression (28.8 %), clinical relapse (28.8 %), MRI activity (25.4 %) and adverse reaction (6.8 %). After switching, ARR and EDSS score at month 12 reduced from 0.45 ± 0.54 to 0.08 ± 0.28(p = 0.039), and from 2.00(2.00-3.38) to 1.00(1.00-2.00) (p < 0.001), respectively. And no increase in T1 Gd-enhancing lesions or new/enlarged T2 lesions identified. No clinical relapses, EDSS worsening, and MRI activity were observed in either treatment-naïve or oral DMT-switched MS patient. During follow-up, no serious adverse events were reported. This real-world study revealed a significant decrease in disease activity and progression among MS patients treated with ofatumumab, both in treatment-naïve and oral DMTs-switched patients, while maintaining a well-tolerated safety profile.