News For MS Patients, New Guidelines for Controlling Rare Brain Infection Risk Under Tysabri Treatment For MS Patients, New Guidelines for Controlling Rare Brain Infection Risk Under Tysabri Treatment by Patricia Inacio, PhD | February 17, 2016 Share this article: Share article via email Copy article link The European Medicines Agency Pharmacovigilance Risk Assessment Committee (PRAC), responsible for assessing and monitoring safety issues for human medicines, completed a review on the risk for progressive multifocal leukoencephalopathy (PML) in multiple sclerosis (MS) patients treated with the medicine Tysabri (natalizumab). The issued guidelines have the objective of minimizing patients’ risk. Recently, a study titled “Therapy with natalizumab is associated with high JCV seroconversion and rising JCV index values,” published in the online issue of the journal Neurology, Neuroimmunology and Neuroinflammation, reported that MS patients treated with Tysabri (natalizumab) have an increased risk of developing high levels of antibodies associated with a virus that can cause the rare, but very serious, brain infection PML. MS neurologist Adil Javed, MD, PhD, and Anthony Reder, MD, from the University of Chicago, emphasized the benefits of natalizumab as a therapy for MS. They said early detection and treatment of PML, in the asymptomatic stages of the disease, were shown to be crucial for limiting the degree of brain damage and disability. Hence, since asymptomatic cases of PML are easily detected through magnetic resonance imaging (MRI) scans, PRAC recommends more frequent MRI scans (every three to six months) in patients at higher risk of PML, namely MS patients who have antibodies against John Cunningham virus (a sign that a person has been exposed to the virus), are undergoing treatment with Tysabri for at least two years, and were submitted to previous immunosuppressant medicines before starting on Tysabri. All three factors, once present in the same patient, establish them at a higher risk for PML development. Results from clinical trials suggested that the risk for PML is small, and even lower than previously estimated: antibody index values of 0.9 or less, increasing significantly in patients with index values above 1.5 who are undergoing treatment with Tysabri for longer than two years. Considering these results, the PRAC guidelines note that patients at higher risk of PML have a high antibody index and are undergoing Tysabri treatment for more than two years. PRAC recommends that in patients at higher risk of developing PML, Tysabri treatment should be carefully evaluated and the medication only continued if patient benefits clearly outweigh the risks. Patients with a low antibody index and no use of immunosuppressant drugs before initiating Tysabri should also be carefully monitored, and undergo an antibody test every six months after they have been on Tysabri therapy for a period longer than two years. Print This Page About the Author Patricia Inacio, PhD Patricia holds her PhD in cell biology from the University Nova de Lisboa, Portugal, and has served as an author on several research projects and fellowships, as well as major grant applications for European agencies. She also served as a PhD student research assistant in the Department of Microbiology & Immunology, Columbia University, New York, for which she was awarded a Luso-American Development Foundation (FLAD) fellowship. Tags European Medicines Agency, guidelines, MRI scans, progressive multifocal leukoencephalopathy (PML), Tysabri (natalizumab)
March 28, 2024 Columns by Benjamin Hofmeister Multiple sclerosis awareness is for people with MS, too
March 28, 2024 News by Lindsey Shapiro, PhD Restoring ‘lost’ pathway of neuroprotection benefits MS mice