Safety Monitoring and Switching Considerations for Ofatumumab in Relapsing MS

Ensuring safety over the course of high-efficacy therapy remains a central concern in the management of relapsing multiple sclerosis (MS). As more patients initiate potent disease-modifying treatments earlier in their disease course, clinicians must balance efficacy with vigilant monitoring for infections, laboratory abnormalities, and complications related to immunosuppression, particularly when transitioning between therapies. Structured protocols before, during, and after treatment can help mitigate risk and guide timely adjustments in care.

In this episode, Mitzi Joi Williams, MD, the founder and chief executive officer of Joi Life Wellness Group Multiple Sclerosis Center, describes her 3-phase framework for safety monitoring with ofatumumab (Kesimpta; Novartis) in relapsing MS: pretreatment, during treatment, and posttreatment. Prior to initiation, she emphasizes the importance of reviewing vaccination status, including timing of live attenuated and inactivated vaccines, and confirming varicella-zoster virus immunity. Baseline testing also includes hepatitis B serology to identify active infection or prior exposure that may require hepatology input, as well as a “usual suspects” panel that assesses white blood cell counts, liver function, electrolytes, and screens for infections such as HIV and tuberculosis.

Williams explains that once patients are on ofatumumab, she typically obtains laboratory studies every 6 to 12 months, focusing on immunoglobulin levels and white blood cell counts to monitor for hypogammaglobulinemia and other treatment-related changes. When switching therapies, she generally aligns the start of a new high-efficacy or depleting agent with the timing of the next ofatumumab dose, while some moderate- to lower-efficacy therapies may be initiated sooner to avoid gaps in treatment. She also underscores the importance of tracking nonlaboratory signals, such as recurrent urinary tract or upper respiratory infections, as potential indicators to reevaluate therapy and overall immunosuppressive burden.