Imatinib has been approved to treat children newly diagnosed with Philadelphia chromosome–positive acute lymphoblastic leukemia, the Food and Drug Administration announced Jan. 25.
Imatinib (Gleevec), a tyrosine kinase inhibitor, should be used in combination with chemotherapy to treat children with Philadelphia chromosome–positive (Ph+) acute lymphoblastic leukemia (ALL).
"Today’s approval is the result of continuous interactions among the FDA, the Children’s Oncology Group and the National Cancer Institute to provide new and better treatments to American children with cancer," Dr. Richard Pazdur, director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research, said in an FDA statement announcing the approval.
Imatinib’s safety and effectiveness for this new indication were established in a clinical trial conducted by the Children’s Oncology Group and sponsored by the National Cancer Institute. The trial enrolled children and young adults 1 year and older with high-risk ALL, defined having a greater than 45% chance of causing complications within 5 years of treatment.
There were a total of 92 patients with Ph+ ALL who were divided into five treatment groups, with each successive group receiving a greater duration of imatinib treatment in combination with chemotherapy. Of the 50 Ph+ ALL patients who received imatinib for the longest duration, 70% had event-free survival with no relapses or deaths within 4 years. Patient deaths declined with increasing duration of imatinib treatment in combination with chemotherapy.
The most common side effects observed in the study included decreased levels of neutrophils, decreased levels of blood platelets, liver toxicity, and infection.
Imatinib was granted accelerated approval in 2001 to treat patients with blast crisis, accelerated phase or chronic phase Ph+ chronic myeloid leukemia who had failed interferon-alpha therapy. Imatinib was subsequently approved to treat several conditions, including newly diagnosed Ph+ chronic myelogenous leukemia in children and in adults with Kit (CD117)-positive gastrointestinal stromal tumors that have been surgically removed.