TOTAL-BODY IRRADIATION AND HIGH-DOSE CYCLOPHOSPHAMIDE, BCNU AND VP-16(CBV) AS A NEW PREPARATORY REGIMEN FOR ALLOGENEIC BONE-MARROW TRANSPLANTATION IN PATIENTS WITH ADVANCED HEMATOLOGIC MALIGNANCIES

To increase the cure rate of advanced hematologic malignancies followi ng allogeneic bone marrow transplantation we sequentially evaluated tw o intensified conditioning regimens. Eleven patients with acute myelob lastic leukemia (AML) beyond the first complete remission or chronic m yelogenous leukemia (CML) not in first chronic phase received an assoc iation of 13.5 Gy of fractionated total body irradiation (TBI) followe d by cyclophosphamide (CY) 120 mg/kg. Following this regimen, the prob ability of relapse was 47% at 3 years and the non-relapse mortality ra te was 27%. Given the acceptable tolerance of this regimen, 13.5 Gy fr actionated TBI was associated with intensified chemotherapy consisting of a combination of CY 120 mg/kg, carmustine 300 mg/m(2) and etoposid e 600 mg/m(2) (CBV). This regimen was administered to 22 patients with comparable diseases. Of these patients, 7 received a transplant from a matched unrelated donor and 2 other patients received a second trans plant from the original genoidentical donor. For 15 patients with a ge noidentical donor, including the 2 second transplant, the 3 year proba bility of survival, disease-free survival and relapse are 40%, 40% and 14%, respectively. No regimen-related toxic deaths were recorded duri ng the first 100 days. Of 7 patients with matched unrelated donors, 3 died before day 100, one death being directly attributable to the regi men. Early non-fatal regimen-related toxicity consisted mainly in grad e II mucositis with no grade III or IV toxicity in recipients of genoi dentical marrow. The late deaths were mainly due to chronic GVH-relate d complications. In conclusion, the association of fractionated 13.5 G y TBI and CBV carries a high antileukemic activity and an acceptable t oxicity, It could be used for patients with standard risk leukemia. Wh ether its antitumor activity is sufficient to allow increased GVH prop hylaxis remains to be evaluated.