Alemtuzumab is primarily used in the treatment of certain types of blood cancers, particularly chronic lymphocytic leukemia (CLL). It works by targeting and binding to CD52, a protein found on the surface of certain immune cells, leading to their destruction. This makes it effective in reducing the number of cancerous B-cells in patients with CLL. Additionally, alemtuzumab is utilized in the management of multiple sclerosis (MS), specifically for relapsing-remitting forms of the disease. It helps by resetting the immune system, reducing the frequency and severity of relapses. The treatment involves short courses of administration, which can lead to long-lasting effects in controlling the progression of MS. In clinical settings, alemtuzumab is administered intravenously, and its use is closely monitored due to potential side effects, including infusion reactions and increased risk of infections. Regular follow-ups and supportive care are essential to manage these risks effectively.