Common brand names

• Campath

How it is administered

Alemtuzumab is given as an intravenous (IV) infusion. For blood cancers, such as B-cell chronic lymphocytic leukemia (B-CLL), it is administered over 2 hours, with a gradual dose escalation to a maximum of 30 mg per dose, three times per week for up to 12 weeks. The medication comes as a clear, colorless solution in a single-dose vial and must be diluted before administration. It is not given as a rapid IV push or bolus.

Premedication with an antihistamine and acetaminophen is recommended before each dose to help reduce infusion-related reactions. Additional medications, such as corticosteroids, may be used if needed.

How it works

Alemtuzumab is a monoclonal antibody that targets CD52, a protein found on the surface of certain immune cells, including B and T lymphocytes, monocytes, macrophages, and some granulocytes. When alemtuzumab binds to CD52 on these cells, it triggers the immune system to destroy them through antibody-dependent cellular cytolysis and complement-mediated lysis.

By depleting these immune cells, alemtuzumab reduces the number of abnormal lymphocytes present in blood cancers like B-CLL. This helps control the disease by lowering the cancer cell burden. However, this also leads to a significant reduction in normal immune cells, which can increase the risk of infections and other immune-related side effects. The effects on immune cells can be long-lasting, and recovery of certain lymphocyte populations may take months to years.

Who should take it

Alemtuzumab is indicated as a single agent for the treatment of B-cell chronic lymphocytic leukemia (B-CLL). It may also be considered in other blood cancers where CD52 is expressed, although its primary FDA-approved use is for B-CLL.

Patients who have not responded to other treatments or who have relapsed may be considered for alemtuzumab therapy. The use of alemtuzumab in rare blood cancers such as Large Granular Lymphocytic Leukemia (LGL) is not specifically approved, but it may be used off-label in certain cases where other treatments have failed and the disease expresses CD52. Treatment decisions should always be made in consultation with a hematologist/oncologist.

Who should not take it

Alemtuzumab should not be used in patients with active, serious infections, as it can further suppress the immune system and worsen infections. It is also not recommended for patients who have had a known hypersensitivity or severe allergic reaction to alemtuzumab or any of its components.

There are no absolute contraindications listed for Campath (alemtuzumab) in the treatment of B-CLL, but caution is advised in patients with a history of autoimmune cytopenias, bone marrow aplasia, or those with significant immunosuppression. It should not be given to pregnant or breastfeeding women due to potential harm to the fetus or infant. Safety and effectiveness in pediatric patients have not been established.

Commonly used with

Alemtuzumab is often used with supportive medications to reduce the risk of side effects and infections. These include:

• Antihistamines and acetaminophen (to prevent infusion reactions)
• Corticosteroids (for severe infusion reactions)
• Antiviral prophylaxis (such as famciclovir) to prevent herpes infections
• Antibiotic prophylaxis (such as trimethoprim/sulfamethoxazole) to prevent Pneumocystis jirovecii pneumonia (PCP)

It is not typically combined with other chemotherapy agents during treatment, but may be used in sequence with other therapies as part of a broader treatment plan.

Commonly tested with

In clinical studies, alemtuzumab has been compared to other chemotherapy agents, such as chlorambucil, for the treatment of B-CLL. It has also been studied in combination with or after other chemotherapies, including alkylating agents and fludarabine, particularly in patients who have relapsed or are refractory to standard treatments.

Routine laboratory monitoring is essential during alemtuzumab therapy, including frequent complete blood counts (CBC), CD4+ lymphocyte counts, and infection surveillance. Additional supportive medications are tested alongside alemtuzumab to manage and prevent side effects.