Abstract

Imatinib mesylate, an inhibitor of the Bcr-Abl tyrosine kinase, has modest activity in refractory/relapsed Philadelphia chromosome (Ph)-positive acute lymphocytic leukemia (ALL). Use of concurrent chemotherapy and imatinib mesylate in newly diagnosed Ph-positive ALL was explored. There were 20 patients who received hyper-CVAD (cyclophosphamide, vincristine, Adriamycin, and dexamethasone) and imatinib mesylate followed by imatinib mesylate-based consolidation/maintenance therapy. Of these patients, 11 had de novo disease, 4 were primary failures after induction (without imatinib mesylate), and 5 were in complete remission (CR) after induction (without imatinib mesylate). All 15 patients treated for active disease achieved CR. Within a median of 3.5 months in first CR, 10 patients underwent allogeneic stem cell transplantation (SCT). One patient relapsed after matched related SCT. The other 9 patients remained alive in CR with median follow-up of 12 months after SCT (range, 1+ to 17+ months). Among 10 patients ineligible for (no donor or older age) or refusing allogeneic SCT, 1 patient relapsed after one year. There were 5 patients who remained alive in continuous CR for a median of 20 months (range, 4+ to 24+ months), with 2 older patients dying in CR at 15 and 16 months of comorbid conditions. Molecular CRs were achieved in both groups (SCT or no SCT). Outcome with hyper-CVAD and imatinib mesylate appears better than with prior regimens; continued accrual and longer follow-up of the current cohort is needed.