Autologous Bone-Marrow Transplantation With Monoclonal-Antibody Purged Marrow For High-Risk Acute Lymphoblastic-Leukemia

Fifty-four patients with acute lymphoblastic leukemia (ALL: 1 relapse, 21 high risk first complete remission (CR 1), 29 second CR (CR 2), and 3 third CR (CR 3) were treated by autologous bone marrow transplantation at three centers. Before storage, the marrows were purged ex vivo with appropriate MAbs RFAL3 (CD10), SB4 (CD19), and RFT2 (CD7), with rabbit serum as the source of complement. All patients received total body irradiation either 750 cGy (middose 15 cGy/min) as a single fraction or 6 x 200 cGy over 3 days (midline dose 16 cGy/min) with lung shielding from 1,100 cGy. The patients who received 750 cGy also received cyclophosphamide or the same drug combined with ara-C or prednisone, teniposide, vincristine, ara-C, and dauno-rubicin. Patients receiving 200 cGy x 6 also received either cyclophosphamide, melphalan, or ara-C and cyclophosphamide. Three patients died of post transplantation complications (interstitial pneumonia, hepatitis B liver necrosis, or encephalitis). This gives a procedure related mortality of 5%. Nonfatal complications were 10 cases of septicemia, 4 interstitial pneumonia, 2 interstitial nephritis, 1 veno-occlusive disease (VOD), and 1 case of hemolytic uremic syndrome. The patient autografted in relapse died of relapse within 2 months. In CR 1 6 or 21 patients have had a relapse, and the actuarial leukemia free survival from CR is 65% (median follow-up 16 months). In CR 2-3 18 of 32 patients have relapsed, and the actuarial leukemia free survival is 31% (median follow-up 18.5 months) from CR. Twelve patients have achieved an inversion, (i.e., present CR longer than previous CR), with a further seven with the potential to achieve inversion. We conclude that ABMT in high risk ALL has a low procedure related mortality (5%), and there are few other complications. The in vitro purging with MAbs had no adverse effect on bone marrow reconstitution, but this study was not designed to demonstrate its antileukemic efficacy. The actuarial leukemia free survival time in the present study for patients with high risk CR 1 and the inversions in CF 2-3 are promising and indicate a potential beneficial effect of ABMT.