Possible Prognostic Benefit from ABMT in First Remission Adult Acute Lymphoblastic Leukemia

We analyzed the long-term results of a phase II trial closed in 1993, including ABMT (autologous bone marrow transplant) with post-graft chemotherapy as consolidation therapy for first remission adult ALL patients. Seventy-nine patients in remission after ‘IVAP’ (idarubicin-vincristine-L-asparaginase-prednisone) were to receive 4 consolidation cycles followed by marrow harvest (unpurged), cranial irradiation, and ABMT after BCNU 300 mg/m2, etoposide 900 mg/m2, and melphalan 110 mg/m2 (restricted to patients 15–50 years-old). The ABMT regime was intentionally of „limited“ intensity, to minimize the risks of toxic death and to resume promptly continuation therapy with alternate drug pairs for 12 weeks and low-dose maintenance with mercaptopurine and methotrexate for 6 mos. (ABMT) or 18 mos. (no ABMT). At the end of early consolidation 67 patients were alive and still in CR: 10 underwent an allogeneic BMT, 32/47 aged 50 years had chemotherapy without transplants. Long-term disease-free survival was positively affected by the following variables: age <35 years /blast count <25×109/l (P<0.001), good treatment realization score (P<0.001), t(9:22)/BCR-ABL negativity (P<0.01), allogeneic BMT and ABMT (P P<0.01, P<0.005), and pre-B CD10+ phenotype (P<0.05). The 5-year DFS rate was 73% for standard-risk patients (age <35, blast count <25×109/l, and Ph/BCR negativity) receiving treatment without major alterations/attenuation and therefore including ABMT in most instances (P<0.001). However, the prognosis of high-risk cases was uniformly poor. This analyis suggested a possible prognostic benefit from ABMT followed by further chemotherapy in standard-risk adult ALL. However, because treatment was scarcely effective in high-risk ALL and good DFS results can be obtained without ABMT in standard-risk cases, the exact role of this therapeutic procedure in specific risk classes remains undetermined.