New Phase III Study Shows Strong Efficacy and Favorable Safety Profile With Single-Agent MabCampath(R) (alemtuzumab) for Patients with Previously Untreated B-CLL
Leeds, England (ots/PRNewswire) -
- Significant Response Rates and Manageable Side Effects Also Exhibited In Poor-Prognosis and Difficult-to-Treat Patients
According to interim data from a new international Phase III study called CAM 307, previously untreated patients with progressive B-cell chronic lymphocytic leukemia (B-CLL) exhibited strong response rates and a favourable toxicity profile when treated with the monoclonal antibody MabCampath(R) (alemtuzumab), when compared to patients who were treated with chlorambucil. The initial results were presented at the 42nd Annual Meeting of the American Society of Clinical Oncology.
Results from the open-label, randomized trial demonstrated that of the 297 patients, the overall response rate (ORR) for MabCampath was 83 percent versus 56 percent for chlorambucil (p = less than 0.0001), which represents a 27 percent greater ORR with MabCampath. The complete response (CR) was 24 percent for MabCampath versus two percent for chlorambucil (p = less than 0.0001). Currently, chlorambucil is considered by many to be the standard front line therapy for patients with B-CLL.
"This study marks the first time we have been able to examine MabCampath as a first-line therapy compared to standard chemotherapy, and we are very encouraged by the results," stated lead investigator Peter Hillmen, M.D, Ch.B, Consultant Haematologist, Leeds General Infirmary, Leeds, United Kingdom. "When compared to chlorambucil treatment, patients with CLL had much higher response rates and with an acceptable toxicity profile. Furthermore, we encountered promising response rates in certain difficult to treat patient populations, particularly those with 11q and 17p deletions."
In an independent review of response, statistically significant ORR to MabCampath therapy was found in patients with 11q deletions, common cytogenic abnormalities observed in hematological malignancies. Patients with 13q deletion, a common genetic event seen in patients with B-CLL, had a statistically significant CR and ORR to MabCampath treatment. The IRR also revealed a difference in patients with 17p deletions, although, due to the lower pool of patients in this grouping, the difference was not deemed statistically significant.
Further evaluation of the CAM 307 responders is ongoing and full results are expected later this year.
About Study Design
The open-label trial randomized 297 patients with previously untreated, progressive disease requiring treatment at 44 medical centers in Europe and the United States. Patients were treated with either 30 mg of MabCampath IV three times per week for a maximum of 12 weeks inclusive of dose escalation periods, or 40 mg/m2 of chlorambucil PO once every 28 days to a maximum of 12 cycles.
Progression-free survival was the primary endpoint, and secondary endpoints included safety, overall and complete response rates, and overall survival.
CLL is the most prevalent form of adult leukemia, affecting approximately 120,000 people in Europe and the United States. The disease is most commonly diagnosed among people age 50 or older. CLL is characterized by the accumulation of functionally immature white blood cells (lymphocytes) in the bone marrow, blood, lymph tissue, and other organs. Two types of lymphocytes are present in the blood, B cells and T cells. About 95 percent of CLL cases involve cancerous B cells. Because these B cells have a longer than normal life span, they begin to build up and "crowd out" the normal, healthy blood cells. The accumulation of functionally immature cells in the bone marrow excludes the generation of healthy cells and can become fatal. Symptoms include fatigue, bone pain, night sweats, fever, and decreased appetite and weight loss. Bone marrow involvement also leads to weakening of the immune system, exposing the patient to a higher risk of infection.
MabCampath is the first and only humanized monoclonal antibody approved for B-CLL therapy and the first product with proven efficacy in CLL patients who have failed both alkylating agents and Fludara (fludarabine phosphate) treatment. No other therapy has shown comparable efficacy in this group of patients. MabCampath has a completely different mode of action compared with conventional chemotherapy. By selectively targeting the CD52 antigen, expressed at higher concentration on malignant lymphocytes, MabCampath activates cellular processes that lead to the lysis of malignant cell types. These processes also result in removal of malignant lymphocytes from the bone marrow, blood, and other affected organs.
Head of Media Relations
Leeds Teaching Hospitals
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Greg Moulds, Head of Media Relations, Leeds Teaching Hospitals,