Phase II Study of Intensive Post-remission Chemotherapy and Stem Cell Transplantation for Adult Acute Lymphoblastic Leukemia and Lymphoblastic Lymphoma: Japan Clinical Oncology Group Study, JCOG9402

Abstract

To evaluate the efficacy and safety of intensive post-remission chemotherapy for untreated patients aged 15-69 years with adult acute lymphoblastic leukemia and lymphoblastic lymphoma in a multicenter Phase II study. The chemotherapy regimen consisted of induction, post-remission and maintenance for 2 years. The primary endpoint was 5-year progression-free survival, and secondary endpoints included complete remission rate, overall survival and adverse events. Among 115 patients enrolled, 108 eligible patients [median age, 33.5 years (range, 15-69)] including 96 acute lymphoblastic leukemia and 12 lymphoblastic lymphoma were assessed. Other major characteristics were male 50%, T-cell phenotype 21%, Philadelphia chromosome 22%, B-symptom+ 35% and performance status 2/3 22%. Eighty-seven patients achieved complete remission (81%; 95% confidence interval 72-88%), while five (5%) died during the chemotherapy protocol. The median overall survival and progression-free survival were 1.8 years (95% confidence interval, 1.5-2.6) and 1.2 years (95% confidence interval, 0.8-1.6), respectively. Their 5-year overall survival and progression-free survival were 29 and 28%, respectively. The 5-year overall survival of 31 patients who underwent allogeneic (n = 19) or autologous (n = 12) stem cell transplantation during first complete response was 51%. Major non-hematologic toxicities of Grade 3 or greater were infections (21%) and pulmonary complications (6%). When compared with the investigators' previous Phase II trials, JCOG9402 improved progression-free survival and overall survival when compared with JCOG8702; however, it did not show improvement when compared with JCOG9004. Although the intensified induction and post-remission chemotherapy was feasible and 28% of the patients with adult acute lymphoblastic leukemia or lymphoblastic lymphoma achieved long-term progression-free survival, JCOG9402 did not show improvement.