A new study indicates that rituximab is more effective than fingolimod for preventing relapses in patients with highly active multiple sclerosis switching from treatment with natalizumab.

The Annals of Neurology study included patients infected with JC virus, which is present in approximately 50% of the general population. While the virus generally causes no problems under normal circumstances, it can cause progressive multifocal leukoencephalopathy (PML), a serious demyelinating disease of the brain, in patients with immune deficiencies due to disease or immunosuppressant drugs. Natalizumab, which is considered among the most effective treatments for relapsing-remitting multiple sclerosis, is associated with an increased risk of PML, and many patients therefore have to carefully weigh benefits and risks with continued treatment. “Termination of natalizumab treatment has also been suggested to be associated with a risk of rebound disease activity, making it difficult to manage switches in clinical practice,” said Dr. Fredrik Piehl, lead author of the study.

Among 256 patients switching from natalizumab to either rituximab (which depletes circulating B cells) or fingolimod (which sequesters lymphocytes in lymph nodes), 1.8% of patients who switched to rituximab and 17.6% of those who switched to fingolimod experienced a clinical relapse within 1.5 years. This large difference in effectiveness could not be explained by differences in baseline characteristics between the two groups.