Biology and Treatment of Relapsed Acute Lymphoblastic Leukemia

The improvements of therapeutic options for children with acute lymphoblast leukemia (ALL) have changed the way patients with relapsed ALL can best be treated. Due to better upfront therapy, the patients relapsing in the current era are different from those who relapsed a few decades ago. Treatment of relapsed ALL may result in high cure rates in subgroup of patients, e.g., in late occurring relapses of B-lineage ALL, whereas cure rates in early relapsing B-lineage ALL and in T-lineage ALL still lag behind, despite intensive, highly toxic treatment. Therefore, studies to the role of more effective and less toxic regimens such as cellular immunotherapy and new immunotherapeutic drugs are urgently needed.