Phase II Pilot Study of Imatinib Mesylate Combined with Induction Chemotherapy in Blast-Phase CML and Ph ALL.

Abstract

Abstract CML in blast crisis (BC) and Philadelphia chromosome-positive (Ph+) ALL are incurable with conventional chemotherapy and in most cases respond only transiently to the Bcr-Abl kinase inhibitor imatinib mesylate. We hypothesized that pretreatment with imatinib would overcome inherent drug resistance to induction chemotherapy mediated by Bcr-Abl, and evaluated the combination in 17 patients with Ph+ acute leukemias (5 CML in BC, 6 de-novo Ph+ ALL, 6 relapsed Ph+ ALL). All patients received a 1-week prephase of imatinib alone at 600 mg daily. In CML in BC and relapsed Ph+ ALL, imatinib was continued concomitantly with induction chemotherapy (standard-dose idarubicin/ara-C..