Update on monitoring and adverse effects of approved second-generation disease-modifying therapies in relapsing forms of multiple sclerosis

Purpose of review There has been a considerable increase in the number of disease-modifying therapies (DMTs) in recent years. It appears that the number of approved DMTs is going to continue to increase in the coming years. The growing number of DMTs has provided a challenge to the clinician to tailor their therapeutic recommendations based on patients' needs and preferences. To choose between these DMTs, knowledge of side-effect profiles is imperative. Recent findings Alemtuzumab, a humanized recombinant monoclonal antibody, was recently approved for the management of relapsing forms of multiple sclerosis. Its use seems to be limited by significant adverse effects and regular monitoring requirement. In 2014, the first case of progressive multifocal leukoencephalopathy (PML) was diagnosed in a patient with relapsing remitting multiple sclerosis who received extended dimethyl fumarate without any significant confounding factors. Among patients receiving fingolimod after previous natalizumab treatment, there have been 17 suspected cases of PML. There have also been three confirmed cases of PML in individuals who received fingolimod without previous natalizumab treatment. Summary In this review, we outline the potential adverse effects and recommended laboratory studies as part of the monitoring strategy following initiation of various DMTs.