Alemtuzumab

Alemtuzumab is a prescription drug used for the treatment of B-cell chronic lymphocytic leukemia (B-CLL). This cancer is characterized by the proliferation of B-cells, a type of white blood cell of the immune system. Alemtuzumab is a monoclonal antibody. Other monoclonal antibodies used to treat cancer include rituximab (Rituxan, MabThera) and trastuzumab (Herceptin). Monoclonal antibodies target specific proteins on the surface of B-cells and cause cell death. The U.S. Food and Drug Administration approved alemtuzumab in May 2001.

Other Names

Alemtuzumab is marketed by Bayer under two brand names:

• Campath
• MabCampath

Uses

Alemtuzumab is used to treat people with B-CLL for whom treatment with other chemotherapeutic agnets (i.e., alkylating agents) and fludarabine (Fludara) had been ineffective.

How Alemtuzumab is Taken

Alemtuzumab is given intravenously (IV) at a concentration of 30 mg/ml. It is given over two hours. The dosing is tapered up to the maximum recommended single dose of 30 mg. Tapering up to 30 mg ordinarily can be accomplished in 3–7 days. The total duration of therapy, including dose tapering, is 12 weeks.

How Alemtuzumab Works

Alemtuzumab is a monoclonal antibody. Antibodies are synthesized by the B-cells of the immune system in response to foreign particles, such as viruses. They bind to, neutralize, and help to remove the foreign particle from the body. Monoclonal antibodies used as medicine are produced and harvested in cells grown in a laboratory. These antibodies are designed to attach to a specific protein expressed on the surface of specific cells. Alemtuzumab binds to a protein called CD52, which is expressed on the surface of several types of white blood cells including B-cells and T-cells. When alemtuzumab binds to this protein, the cancer cells destabilize, break open, and die.

How the Body Affects Alemtuzumab

The time needed for the concentration of alemtuzumab in the blood to be reduced by half, the half-life, increases as dosing progresses and reaches a maximum of approximately six days. How alemtuzumab is metabolized is not known.

Side Effects

One of the most common side effects of alemtuzumabb occurs during infusion. These infusion-related reactions include fever, chills, low blood pressure, nausea, rash, rapid heart beat, and trouble breathing. Other common side effects include the following:

• blood disorders (e.g., low platelet, white blood cell, and red blood cell counts)
• infections (e.g., cytomegalovirus)
• gastrointestinal symptoms (nausea, vomiting, abdominal pain)
• neurological symptoms (insomnia, anxiety)

Alemtuzumab may also affect the blood in other ways and cause bleeding, easy bruising, pale complexion, weakness or fatigue (as a result of anemia).

Risks and Precautions

Infections, especially with cytomegalovirus, are the biggest risk associated with the use of alemtuzumab. The drug also increases the risk of infection from live vaccines given during immunizations. The risk of pre-existing infections, such as HIV infection, progressing or emerging is also elevated by alemtuzumab.

Alemtuzumab may cause harm to a developing fetus. The drug is fully eliminated from the body in six months after discontinuation of treatment, and after this time the risk to a pregnancy is very low.

Drug Interactions

Drug interactions with alemtuzumab have not been studied.

Research

According to one preliminary study, BCLL patients treated with single agent Campath have an excellent response rate.^[1]

The effectiveness of fludarabine in combinaiton with rituximab followed by alemtuzumab was studied in 41 patients with lymphocytic leukemia.^[2] The response rate with the combination treatment was 71% and 34 patients were treated with alemtuzumab, but only 49% of these patients tolerated the drug well enough to complete treatment. Almetuzumab produced a response in 21% of these patients.

References

1. ↑ American Society of Clinical Oncology Web site. Preliminary phase III efficacy and safety of alemtuzumab vs chlorambucil as front-line therapy for patients with progressive B-cell chronic lymphocytic leukemia (BCLL).
2. ↑ Hainsworth JD, Vazquez ER, Spigel DR, et al. Combination therapy with fludarabine and rituximab followed by alemtuzumab in the first-line treatment of patients with chronic lymphocytic leukemia or small lymphocytic lymphoma: a phase 2 trial of the Minnie Pearl Cancer Research Network. Cancer. 2008 Mar 15;112(6):1288-95. Abstract

External Links

Drugs.com