Does natalizumab therapy benefit patients with multiple sclerosis (MS)? The obvious answer is yes. Natalizumab was approved for patients with relapsing forms of MS by regulatory agencies based on the results of 2 phase 3 clinical trials that showed substantial benefits with regard to clinical and paraclinical outcomes.1,2 Post hoc analyses suggest that many who adhere to natalizumab therapy have a high likelihood of being disease free for many years.3 Based on these efficacy data, patients should perhaps be treated with natalizumab indefinitely or until they seem to have transitioned to secondary progressive MS. However, shortly after its initial approval, it was determined that natalizumab use is associated with progressive multifocal encephalopathy (PML), an opportunistic infection of the central nervous system that is caused by the human polyomavirus John Cunningham virus (JCV).
Stüve O, Cutter GR. Does Natalizumab Therapy Benefit Patients With Multiple Sclerosis?. JAMA Neurol. 2014;71(8):945-946. doi:10.1001/jamaneurol.2014.1201