According to results recently presented at the 2006 annual meeting of the American Society of Clinical Oncology (ASCO), Campath® (alemtuzumab) provides significantly superior anticancer responses with acceptable side effects when compared with chlorambucil as initial therapy of B-cell chronic lymphocytic leukemia (CLL).
Chronic lymphocytic leukemia (CLL) is the most common form of adult leukemia. The American Cancer Society estimates that approximately 8,000 people will be diagnosed with CLL this year. Currently, there are approximately 60,000 people in the U.S. living with CLL.
CLL is characterized by the production of atypical lymphocytes. Lymphocytes are specialized immune cells that exist in two forms: B- and T-cells. These cells are produced in the bone marrow and each serves a specific function in aiding the body fight infection.
The large majority of CLL cases involve mature B-lymphocytes that tend to live much longer than normal. B-lymphocytes accumulate in the blood, bone marrow, lymph nodes, and spleen. This results in overcrowding of these areas and suppression of the formation and function of blood and immune cells. Additionally, the cancerous lymphocytes themselves do not function normally, leading to a further reduction in the body’s ability to fight infection.
Campath is a monoclonal antibody that is targeted against B-cells. It has been designed to bind to specific sites on B-cells and cause the immune system to attack the cells to which it is bound. There are additional biological properties of Campath still being evaluated that may also destroy B-cells. Campath is currently approved for the treatment of B-cell CLL in patients whose disease has progressed following Fludara® or other chemotherapy agents referred to as alkylating agents.
Researchers recently conducted a phase III trial (phase of trials prior to FDA review) that directly compared Campath to a commonly used chemotherapy agent chlorambucil as initial therapy in patients with CLL. This trial included 297 patients who had not received prior therapy, but whose cancer was progressing.
- Overall anticancer responses were improved by 27% in patients treated with Campath compared to those treated with chlorambucil (83% versus 56%, respectively).
- Independent review of response (IRR) demonstrated a significantly higher response rate among patients with 11q deletions, a group of patients considered difficult to treat, and a significantly higher complete disappearance of detectable cancer (complete response) and overall anticancer response in patients with 13q deletions.
- Researchers stated that side effects were acceptable with Campath.
- Longer follow-up will continue with this trial to determine progression-free survival and overall survival between the two groups of patients.
The researchers concluded that Campath used as initial therapy in patients with progressive B-cell CLL provides significantly superior responses compared with chlorambucil while maintaining acceptable side effects. Future follow-up results including progression-free survival and safety will be submitted to the FDA for potentially expanding the indication of Campath to include first-line therapy in B-cell CLL.
Reference: Hillmen P, Skotnicki A, Tobak T, et al. Prelminary Phase III Efficacy and Safety of Alemtuzumab vs Chlorambucil as Front-Line Therapy for Patients with Progressive B-Cell Chronic Lymphocytic Leukemia (BCLL). Proceedings from the 42nd annual meeting of the American Society of Clinical Oncology. June 2006. Atlanta, GA. Abstract #6511.
Related News: Campath® Following Fludara® Improves Responses in Chronic Lymphocytic Leukemia(5/2/2006)