A Multicenter Study to Assess Response to Influenza Vaccine in Multiple Sclerosis Participants Treated With Ofatumumab

2020-2021, 2021-2022, or 2022-2023 inactivated quadrivalent influenza vaccine. Participants received the vaccine within 9 calendar days after the Screening Visit, before the Week 0 Visit occurred.

"Auto-injector containing 20 mg ofatumumab (20 mg/0.4mL) for subcutaneous (s.c.) administration.~* Participants in Cohort 1 received loading doses of 20 mg ofatumumab s.c. at Weeks 2, 3, and 4 in the Investigational Period. In the open-label Extension Period, they administered the first dose of ofatumumab at Week 6 and continued monthly dosing until the final dose at Week 26. Novartis supplied participants in Cohort 1 with ofatumumab treatment.~* Participants in Cohort 2 continued on their commercially prescribed ofatumumab treatment during the Investigational Period. In the open-label Extension Period, they continued to administer ofatumumab monthly until the final dose at Week 28. Cohort 2 participants in the extension could have either remained on their prescribed ofatumumab or switched to study supplied ofatumumab."

Participants in Cohort 3 continued on their commercially prescribed injectable disease modifying therapy (iDMT) during the Investigational Period.