New agents for the treatment of patients with acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) has a bimodal age distribution with a peak occurring during early childhood and a second peak after age 45. Although all patients are treated with similar intensive chemotherapy regimens, good outcomes have occurred more frequently in children than adults. Most children with ALL have been able to achieve a complete remission (CR) with an induction rate of about 98% and a 5-year estimated event-free survival rate (EFS) rate of about 80%. Unfortunately, the results for adults are less encouraging. Current adult treatment regimens result in CR rates approaching 80%, with EFS at 5 years of only 30% to 40%. Regardless of age, patients with relapsed or refractory ALL have extremely poor outcomes, because CR rates are low and seldom durable. Clearly, new agents are required to improve the outcome of patients with relapsed or refractory ALL.