Complete remission of third recurrence of acute myeloid leukemia after treatment with Imatinib (STI-571)

We report the case of a 76-year old patient with third relapse of AML who was successfully treated with Imatinib. The decision to try Imatinib was guided by bright expression of c-kit on the patient's blasts. Treatment was well tolerated but the dose was reduced for pancytopenia and later stopped completely because of pneumonia. The patient recovered with i.v. antibiotics, antimycotics and s.c. G-CSF. Reevaluation of the bone marrow after the end of treatment demonstrated the absence of malignant blasts. Treatment with Imatinib was started again with the intention to prolong remission duration. During the following months peripheral blood counts stabilized in the normal range indicating that a fourth complete remission has been achieved in this patient. This is the first report demonstrating that Imatinib can induce complete remission in relapsed c-kit positive AML in an elderly patient. Prolonged cytopenia remains a considerable problem indicating that normal haematopoiesis is not completely independent of the signalling cascades inhibited by Imatinib. Nevertheless our report supports further study of this drug in c-kit positive AML.