Three brand new studies shed light on use of natalizumab in relapsing-remitting multiple sclerosis.
Natalizumab is a highly effective therapy for relapsing-remitting multiple sclerosis. However, its efficacy in the context of other more recently available treatments needs to be assessed. Further, hampering the long-term of use of natalizumab is the association of treatment with a risk of progressive multifocal leukoencephalopathy (PML).The slides above highlight findings of 3 new studies of natalizumab.  Â
A clinical trial that directly compares natalizumab with fingolimod is unlikely, but a well-performed observational study can serve as the next best thing. Using this approach, Kalincik and colleagues showed that natalizumab is better than fingolimod. Using MSBase, a large international, observational MS registry, these researchers identified patients with MS experiencing relapses or disability progression within the 6 months immediately preceding a switch to natalizumab or fingolimod. Compared were 578 patients with MS (natalizumab, n=407; fingolimod, n=171); the mean follow-up was 12 months.
Few studies have estimated the association between natalizumab persistence and relapse-related outcomes using “real-world” data (nonâclinical trial setting). Using a US medical insurance claims database, researchers identified US patients who initiated natalizumab therapy and had at least 2 years of follow-up. Persistence was defined as no 90-day or greater gap in natalizumab therapy. Relapse was defined as an MS-related hospitalization or outpatient visit with intravenous or oral steroid claim within 7 days. The study identified 2407 natalizumab initiators who had at least 2 years of follow-up. Persistent to non-persistent treatment change was associated with a mean relapse-rate increase of 0.23.
The objective of this analysis was to examine outcomes in a large natalizumab-associated PML population. MS patients with natalizumab-associated PML identified through postmarketing surveillance were monitored for up to 24 months using a structured questionnaire completed by treating physicians. Among the 336 patients in this analysis, 76% survived. Survivors were significantly younger at diagnosis, had significantly lower EDSS scores prior to PML diagnosis, and had significantly lower cerebrospinal fluid JC viral load at the time of diagnosis.
