Effect of Alemtuzumab Infusions on Vital Signs: A Prospective Observational Study in Patients with Relapsing-Remitting Multiple Sclerosis

Alemtuzumab efficacy and safety were established in phase 3 randomized trials. We characterize vital signs during and after the first alemtuzumab infusion course. Patients with relapsing-remitting multiple sclerosis commercially prescribed alemtuzumab 12 mg/day on 5 consecutive days (initial course) were enrolled in this prospective, observational study. Preinfusion medications included methylprednisolone, antihistamine, and antipyretics. Primary end point: change from precourse baseline in vital signs during and 2 hours after each alemtuzumab infusion. Secondary end points: infusion duration and serious adverse events (AEs) starting within 24 hours and within 7 days after infusion (AEs collected up to 15 days after treatment). Potentially clinically significant vital sign abnormalities were based on predefined thresholds from literature review. In the 304 patients treated, minimal increases in mean systolic (≤8 mm Hg) and diastolic (≤3 mm Hg) blood pressures from precourse baseline were observed on infusion days 3 to 5. An increase in mean heart rate (20 beats per minute) during the first infusion day normalized by day 2, and smaller increases (5 beats per minute) occurred during subsequent infusions. Serious AEs occurred in two patients (0.7%) during or within 24 hours after infusion and in three patients (1.0%) within 7 days. Mean/median infusion duration was 4 hours. Vital sign abnormalities with potential clinical significance occurred in 62.5% of patients. Although most patients had potentially clinically significant vital sign abnormalities, mean changes from baseline during and after infusion of the first alemtuzumab course were clinically insignificant. No new safety signals were detected.