Acute myelogenous leukemia (AML) is the most coomon acute leukemia in adults with and annual incidence of 4 cases per 100 000 inhabitans. Median age at diagnosis is 70 years. For patients below 55 years, the prognosis has gradually improved the last decades, but elderly patiens still do poorly; the survival being around 30% with no improvement of outome after standard chemotherapy treatment.
The curative potential of allogeneic hematopoietic stem cell transplantation (HCT) is due to the high-dose preparative chemotherapy (conditioning), and the immunological graft-versus-leukemia (GvL-) effect exerted by the donors´s immune cells . HCT is afflicted with non-relapse mortality (NRM), and sometimes severe late side effects (mainly chronic Graft-versus-Host Disease), and its use in AML was previously restricted to younger patients.
In elderly patients, HCT with reduced doses of chemotherapy before pre- transplant (reduced intensity conditioning; RICT), is feasible and has quickly become a widespread treatment modality in AML. The intuitively attractive notion behind the RICT concept is that patients´ strain and ensuing complications will diminish, and that the GVL-effect will eradicate all leukemic cells. In Europe, 1/3 of transplants are RICTs in patients >55 years. Results of RICT in elderly AML are promising, but there are no prospective controlled study supporting this clinical practice.
Consequently, there is an urgent need to evaluate RICTs which remains a risky and resource-consuming treatment. In an ongoing, academic, international, prospective trial we aim to fill this knowledge gap and evaluate the impact of RICT on survival and quality of life in elderly AML patients. We use a novel study design allowing both HLA matched siblings and unrelated donors, and a strict scheme for registration, inclusion and allocation of patients to avoid selection biases. Most other study procedures are pragmatic and adhere to clinical routines. The trial has the potential to be the first to evaluate RIC transplants in AML.
