SELECTIVE OVERSHOOT OF PH-NEGATIVE BLOOD HEMATOPOIETIC-CELLS AFTER INTENSIVE IDARUBICIN-CONTAINING REGIMEN AND THEIR REPOPULATING CAPACITY AFTER REINFUSION

Twenty-seven patients with chronic myelogenous leukemia (CML)-17 in th e chronic phase and 10 in the accelerated phase-were treated with an i ntensive chemotherapy regimen consisting of idarubicin, arabinosylcyto sine, and etoposide. All patients were ineligible for bone marrow tran splantation (BMT) and showed little or no cytogenetic response to inte rferon alpha (IFN-alpha). Blood hemopoietic cells (BHC) were collected by leukapheresis in all patients during early recovery from chemother apy-induced aplasia. In 13/27 patients (48%), all metaphases were Ph-n egative (Ph-); in another five patients, the percentage of Ph-positive (Ph+) metaphases decreased to less than 50%. Complete Ph+ disappearan ce was found in 66% of the patients treated within two years of diagno sis and in only 30% of those treated later. The collected Ph- cells ha ve been used as autotransplants in nine patients: seven have shown sus tained engraftment, and five are alive and well, with Ph- at 3+, 4+, 7 +, 11+, and 19+ months after transplant. It is remarkable that one pat ient, now Ph- at 19 months after transplant, is also PCR negative. The se results suggest that it is possible to collect Ph- hemopoietic cell s even years after diagnosis and to perform autologous transplants wit h these cells.