Time to Response to Gleevec® in Chronic Myeloid Leukemia Does Not Affect Outcomes
Posted by rob on January 24, 2006 under Uncategorized | 
Be the First to Comment
Time to Response to Gleevec® in Chronic Myeloid Leukemia Does Not Affect Outcomes
According to a recent article published in the Journal of Clinical Oncology, the time it takes for a patient to achieve an anticancer response to Gleevec (imatinib) does not appear to affect outcomes; patients who achieved responses within one year or after one year of therapy achieved the same survival outcomes. Chronic myeloid leukemia (CML), also called chronic granulocytic leukemia, is a cancer that originates in the immune cells. It affects approximately 4,600 people annually in the U.S. In the case of CML, large numbers of young immune cells do not mature, resulting in an excess accumulation of these cells. These leukemia cells then crowd the bone marrow and blood, suppressing formation and function of other blood cells normally present in these areas. In addition, the leukemia cells cannot perform their function in the body properly, which leaves patients susceptible to infection. Chronic myeloid leukemia begins with a chronic phase, during which few clinical problems, if any, occur. However, when left untreated, the chronic phase progresses into acute phases; these phases are characterized by fast-growing and aggressive cancer and are called the accelerated and blastic phases. Patients reaching these acute phases have a poor prognosis for long-term survival. Historically, the only curative option for patients with CML was an allogeneic stem cell transplant. However, treatment-related mortality, as well as side effects, can be substantial in patients undergoing an allogeneic stem cell transplant; researchers have thus focused efforts on curative treatment options that are more easily tolerated. The majority of CML cases are Philadelphia chromosome-positive. In such cases, a genetic abnormality, referred to as the Philadelphia chromosome, results in the constantly activated growth of cancer cells. Gleevec is a biological agent that binds to and slows or stops the uncontrolled growth of cancer cells with the Philadelphia chromosome. In addition, Gleevec has activity in several biological pathways implicated in the development and/or expression of cancer. An advantage of Gleevec over interferon alfa, another drug used to treat CML, is that Gleevec produces few side effects. Researchers from Italy recently analyzed data to determine if patients who achieved a cytogenetic response (measure of active Philadelphia-chromosome positive cells) to Gleevec within one year of treatment have improved outcomes compared to those who achieve a cytogenetic response to Gleevec after one year of treatment. The study included 284 patients with chronic-phase Philadelphia-positive CML who were treated with Gleevec following disease progression after treatment with interferon. Patients remained on treatment with Gleevec as long as their disease did not progress. The time to a cytogenetic response with Gleevec did not impact overall outcomes. Patients who achieved a cytogenic response within one year of treatment with Gleevec were referred to as early responders, and late responders were those who achieved a cytogenetic response after one year of treatment with Gleevec. The researchers concluded that patients with CML who achieve a cytogenetic response after one year of treatment with Gleevec have outcomes similar to those of patients who achieve these responses within one year of treatment; this indicates that a long-term course of treatment with Gleevec may provide impressive long-term survival among these patients. Reference: Iacobucci I, Rosti G, Amabile M, et al. Comparison Between Patients With Philadelphia-Positive Chronic Phase Chronic Myeloid Leukemia Who Obtained a Complete Cytogenetic Response Within 1 Year of Imatinib Therapy and Those Who Achieved Such a Response After 12 Months of Treatment. Journal of Clinical Oncology. 2006;24: 454-459. Related News: Treatment with Gleevec® Continues to Show Benefits in CML (12/28/05)
Time to Response to Gleevec® in Chronic Myeloid Leukemia Does Not Affect Outcomes