The European Medicines Agency (EMA) has recommended new measures to reduce the risk of a rare brain infection in patients with multiple sclerosis (MS) who are prescribed natalizumab (Tysabri).
MS patients treated with natalizumab who have a higher risk of developing progressive multifocal leukoencephalopathy (PML), which is caused by the John Cunningham virus (JC), should have a brain MRI scan every three to six months to check for PML. The recommendation follows a review by the EMA’s Pharmacovigilance Risk Assessment Committee (PRAC).
Risk factors for PML in MS patients include the presence of JC antibodies, treatment with natalizumab for more than two years and the use of immunosuppressant medicines before starting treatment with natalizumab. Patients with all three factors are considered high risk.
Patients with a high antibody index who have not used immunosuppressants before taking natalizumab and have been treated with it for more than two years are also considered at higher risk of PML.
Natalizumab treatment for high-risk category patients should only continue if the benefits outweigh the risks, the PRAC recommends. The committee also recommends biannual antibody testing for other low-risk MS patients.
The PRAC recommendations now go to the EMA’s Committee for Medicinal Products for Human Use for approval.