Efficacy and safety of alemtuzumab treatment in a real-world cohort of patients with multiple sclerosis

Alemtuzumab is a monoclonal anti-CD52 antibody prescribed to treat relapsing–remitting multiple sclerosis (RRMS). Alemtuzumab affects the balance of the immune system by depleting circulating lymphocytes, leading to the formation of a new immune repertoire less likely to induce autoimmune attack against CNS myelin. We collected real-world data of RRMS patients treated with alemtuzumab. We assessed relapse rate, disability progression, and MRI-related disease activity over a 24 month period. Our study included 35 RRMS patients (19 female and 16 male) with a mean age of 37.3 years (SD = 10.5). The patient cohort had a mean disease duration of 10.4 years, median previous disease modifying treatments (DMTs) of 3.0, and a median expanded disability status scale (EDSS) score of 4.0 (IQR 2.5–6.0). Neurological disability remained stable during treatment and there was no statistically significant change in EDSS score. Prior to treatment, the median relapse rate was 2.0 (IQR 1.0–3.0); after treatment the median relapse rate was 0.0. This 2.0 decrease in relapse rate is statistically significant (p < 0.0001). Moreover, the treated patients exhibited a statistically significant decrease in gadolinium (GD) enhancing lesions on MRI [both in number (p < 0.005) and volume (p < 0.005)]. Thirty-three percent of patients reached NEDA-3 (no evidence of disease activity) status by the end of treatment. In a real-world setting, alemtuzumab treatment significantly decreased relapse rate and GD-enhancing lesions while preventing disability progression. Tolerability of treatment was high, with patients experiencing only minor adverse events.