Role of reduced intensity transplant in adult patients with acute lymphoblastic leukemia: If and when?

Although allogeneic transplantation is a potentially curative therapy for adults with acute lymphoblastic leukemia (ALL), the high risk of the ablative regimen limits its use, especially in older patients where the need for better therapy is greatest. Recent observations suggesting that a donor derived graft vs leukemia effect is important is facilitating cure after an allogeneic transplant has kindled interest in utilizing a reduced-intensity approach, which relies in large part on this effect to control and cure the disease. Several trials have now been reported that suggest that a reduced-intensity conditioning (RIC) approach might be very effective, especially in patients who are in the first remission of the disease from either related, unrelated, or cord blood transplant donors, with approximately 50% of patients alive and in remission two years after transplant. These studies suggest that prospective studies of RIC should be conducted in patients with ALL in first remission who are at high risk for relapse based on age or comorbidity to determine its role in the overall management of adult patients with this disease.