We studied 25 patients with
acute nonlymphocytic leukemia in second remission (20 patients) or third remission (5 patients) in whom autologous
bone marrow transplantation was performed with use of marrow incubated ex vivo with the
alkylating agent 4-hydroperoxycyclophosphamide. Patients received intensive cytoreductive
therapy with
busulfan and
cyclophosphamide or
cyclophosphamide and total body irradiation, followed by an infusion of marrow that had been collected in remission, treated with
4-hydroperoxycyclophosphamide, and cryopreserved. Four patients died from bacterial or fungal
sepsis within the first month after
transplantation, and one patient with persistent marrow hypoplasia died from gram-negative
sepsis 155 days after infusion with autologous marrow. In the remaining patients, peripheral-blood levels of neutrophils in excess of 0.5 X 10(9) per liter and platelet counts over 50 X 10(9) per liter were attained at median intervals of 29 and 57 days after
transplantation, respectively. Nine patients had leukemic relapses at 73 to 316 days (median, 182 days) after infusion of autologous marrow, for an actuarial relapse rate of 46 percent. Eleven patients (eight in second remission and three in third) remained in remission at a median of more than 400 days (range, greater than 230 to greater than 1653 days) after
transplantation. The observed disease-free survival after
transplantation with autologous marrow treated with
4-hydroperoxycyclophosphamide compares favorably with the results of syngeneic or
allogeneic transplantation in similar groups of patients.