BACKGROUND: Real-world data is required to provide a greater understanding of the impact of ofatumumab on ability to mount an effective immune response following the receipt of approved COVID-19 vaccinations.
METHODS: Data from patients with multiple sclerosis (MS) treated with ofatumumab and fully vaccinated against COVID-19 infection were retrospectively abstracted from medical charts at 4 clinical sites in the US. Patient characteristics and humoral response were summarized descriptively. Differences in humoral response were documented based upon vaccination status during ofatumumab (i.e., post full vaccination and post booster vaccination) and prior disease modifying treatment (DMT) exposure (i.e., DMT naïve; prior anti-CD20/sphingosine 1-phosphate [S1P]; prior non-anti-CD20/S1P); sample size precluded formal statistical analysis.
RESULTS: 38 patients were included. Duration of ofatumumab treatment upon data collection was a mean (SD) of 20.4 (4.6) months (treatment ongoing for 35 patients [92%]). Definitive humoral response after full vaccination was documented for 34 patients, of whom 20 (60%) were seropositive. Definitive humoral response after booster vaccination was documented among 5 patients, of whom 3 (60%) were seropositive. Among patients who were DMT naïve prior to ofatumumab (n=15), 73% were seropositive; among prior anti-CD20/S1P patients (n=14), 33% were seropositive; and among prior non-anti-CD20/S1P patients (n=9), 56% were seropositive. DMT-naïve patients had been diagnosed with MS for a shorter duration than DMT-experienced patients.
CONCLUSIONS: Patients with MS receiving ongoing treatment with ofatumumab can mount a positive humoral response to COVID-19 vaccination. Prior treatment with anti-CD20 or S1P DMTs may be a risk factor for lower humoral response.
