Assessing understanding of individual risk and symptoms of progressive multifocal leukoencephalopathy in patients prescribed natalizumab for multiple sclerosis.

ABSTRACT

BACKGROUND: Natalizumab, a monoclonal antibody directed against α4 integrin, is a highly efficacious treatment commonly used in relapsing remitting multiple sclerosis. Natalizumab is associated with the potentially fatal, rare, demyelinating, opportunistic brain infection, progressive multifocal leukoencephalopathy (PML). Prognosis and disability from PML are determined by early diagnosis. AIMS: Written tools are mandated in Australia and other prescribing countries with the aim to help patients understand the risks associated with treatment and ensure familiarity with the early symptoms of PML. We aimed to assess if these tools achieve such an outcome. METHODS: A cross-sectional survey was conducted using a convenience sample of multiple sclerosis patients prescribed natalizumab presenting to the infusion centre at a major tertiary hospital. Patients were offered a multi-choice questionnaire to assess their knowledge on the treatment risks and surveillance requirements of their therapy. Three specific questions were highlighted by the researchers as crucial to patient understanding of PML and defined as basic knowledge. RESULTS: A total of 48 patients in our hospital was prescribed natalizumab; 37 responded. A total of 16 (43.2%) patients answered all three basic knowledge questions correctly. There was no difference in the ability to answer these questions based on length of treatment or co-ownership knowledge between patients with base knowledge and without. CONCLUSION: Natalizumab is associated with an increased risk of PML. Early detection and treatment of PML results in improved patient outcomes. Patient knowledge and co-partnership in the utilisation of PML risk tools is relevant in ensuring early detection. Our findings question the ability of currently sanctioned tools to inform patients of basic knowledge of PML and their risk of developing PML. A future study with a repetitive education approach and repeating the questionnaire at multiple time points would be of interest.