Letermovir for the Prevention of Cytomegalovirus Reactivation in Patients With Hematological Malignancies Treated With Alemtuzumab

PRIMARY OBJECTIVE: I. To estimate the rate of cytomegalovirus (CMV) reactivation in patients treated with letermovir at 3 months after completion of alemtuzumab therapy. SECONDARY OBJECTIVES: I. To evaluate the tolerability of letermovir in combination with alemtuzumab. II. To evaluate the efficacy of letermovir for the prevention of clinically significant CMV disease. III. To estimate the progression free survival of patients in the study population. IV. To estimate the overall survival of patients in the study population. EXPLORATORY OBJECTIVE: I. To evaluate mechanisms of antiviral resistance in letermovir prophylaxis failures. OUTLINE: Beginning within 7 days of the first administration of standard alemtuzumab, patients receive letermovir orally (PO) (or intravenously \[IV\] over 1 hour if patient is unable to take PO for an extended period of time) daily on days 1-28. Cycles repeat every 28 days for up to 3 months after the last dose of alemtuzumab in the absence of unacceptable toxicity. After completion of study treatment, patients are followed up at 30 days.