Alemtuzumab (Lemtrada®) is a humanised monoclonal antibody indicated for the treatment of adult patients with relapsing/remitting multiple sclerosis with active disease defined by clinical or imaging features. Alemtuzumab demonstrated superior efficacy over active comparator in both treatment naive patients and those with inadequate response to prior therapy. Alemtuzumab is associated with a consistent and manageable safety and tolerability profile. Treatment with alemtuzumab for multiple sclerosis increases the risk for autoimmune adverse events including immune thrombocytopenia. Complete blood counts with differential should be obtained prior to initiation of treatment and at monthly intervals thereafter for 48 months after the last infusion. After this period of time, testing should be performed based on clinical findings suggestive of immune thrombocytopenia. If immune thrombocytopenia onset is confirmed, appropriate medical intervention should be promptly initiated, including immediate referral to a specialist. This paper presents the consensus of Belgian multiple sclerosis specialists and haematologists to guide the treating physician with practical recommendations.

(BELG J HEMATOL 2018;9(3):118–23)