Study of Three Cases of Primary Refractory T Cell ALL

A significant proportion of T cell acute lymphoblastic leukemia (T-ALL) patients do not achieve complete remission after 4 weeks of induction chemotherapy or relapse early. Salvage chemotherapy for such patients usually results in poor outcome which can be up to 20-30% survival with allogeneic BMT. Nelarabine combined with chemotherapy, in COG AALL0434 study, showed 4-year disease-free survival of 54.8% in patients with primary refractory T ALL. An allogeneic BMT in such patients may further improve outcome. In this report, three patients with primary refractory T cell ALL including a case of ETP-ALL and near ETP-ALL were treated with Nelarabine combined with COG based regime and thereafter an allogeneic stem cell transplantation. All three patients achieved a complete remission with negative minimal residual disease status with one course of therapy, received allo SCT (MSD = 2, Haplo = 1) and are surviving in complete remission at 12 months, 14 months and 25 months of follow up. This report highlights that primary refractory T ALL patient can be successfully treated with Nelarabine in combination with chemotherapy and consolidation with allogeneic SCT to provide maximum chances of long-term survival and cure.