DMT33
Injection-Related Reactions with Subcutaneous Administration of Ofatumumab in Relapsing Multiple Sclerosis: Data from Clinical Studies and Post Marketing Experience
In the ASCLEPIOS I/II trials, injection-related reactions (IRRs; systemic and local-site) with ofatumumab were predominantly reported with the first injection. Most IRRs were mild-to-moderate in severity and non-serious in nature. No life-threatening/hypersensitivity reactions leading to discontinuation were observed. Updated data on IRRs is available from the open-label extension study, ALITHIOS, and in the post-marketing setting.
Objectives:
To report the potential risk of IRRs observed in relapsing multiple sclerosis (RMS) patients treated with ofatumumab, including newly-switched patients in the ALITHIOS trial and in the post-marketing setting.
Methods:
Data from the core ASCLEPIOS I/II, APLIOS, APOLITOS trials and ALITHIOS study (overall, N=1969; patients who received continuous ofatumumab, N=1292; patients newly switched from teriflunomide to ofatumumab, N=677) and from the post-marketing setting (cut-off: 25 Sep 2021) were included in this analysis. Incidence of both systemic and local-site IRRs, severity, seriousness and discontinuations were reported. The most commonly associated symptoms have also summarized.
Results:
Systemic/local-site IRRs were observed in 24.7%/11.8% in the overall population; 25.7%/13.5% in continuous and 22.9%/8.6% in newly-switched groups. Upon first injection, incidence of systemic/local-site IRRs in overall, continuous, and newly-switched groups were 17.4%/3.0%, 17.0%/3.4%, and 18.3%/2.2%, respectively. These rates decreased with subsequent injections. Majority of IRRs (99.4%) were mild-to-moderate (Grade 1/2) in severity. No life-threatening IRRs were observed. Four patients (0.6%) with systemic IRRs and 1 patient (0.1%) with local-site IRRs discontinued the treatment in newly-switched group. The most common systemic IRR symptoms (≥5%) were fever, headache, chills, fatigue, and local-site IRR symptoms (≥3%) were erythema/redness and pain. In the post-marketing setting, with an estimated exposure of 4,713 patient-years, no medically confirmed fatal or life-threatening IRRs were identified. There were 8 medically confirmed serious cases: 7 patients were hospitalized, 1 patient in which the events were determined to be medically significant but did not require hospitalization.
Conclusions:
Systemic and local-site IRRs reported upon first injection with ofatumumab in the core clinical studies and ALITHIOS trial, including in newly-switched patients and in the post-marketing setting were mostly mild-to-moderate in severity.