Most patients achieve a remission (an absence of signs and symptoms) after initial treatment for acute myeloid leukemia (AML). However, some patients have residual leukemic cells in their marrow even after intensive treatment. This is referred to as "refractory leukemia."
For refractory AML, treatment options may include drugs not already used during the first course of treatment. Stem cell transplantation may be used when remission is achieved, which may result in a more durable remission
Some patients reach remission and then have a return of leukemia cells in the marrow and a decrease in normal blood cells. This is called “relapsed leukemia.”
In patients who relapse, the duration of the remission, the patient’s age and the cytogenetic findings in the leukemia cells influence the approach to therapy. Drugs similar to those administered initially, different drugs or stem cell transplantation may be used to treat the leukemia.
Stem Cell Transplantation in Relapsed Patients
Allogeneic stem cell transplantation may be a treatment option for patients in early first relapse or second remission, although this is a high-risk procedure. For patients who lack a sibling donor, matched-unrelated donor transplants can be effective. Patients with AML who relapse after allogeneic stem cell transplantation may have a long-term remission if they have a second transplant. Donor leukocyte infusion is sometimes used to treat relapsed AML post transplant. This therapy is most effective in early relapses and in the absence of extensive chronic graft-versus-host disease (GVHD).
For some patients with relapsed or refractory AML, the best treatment route may be one that is being studied in a clinical trial. Several drugs and drug combinations used to treat AML are currently being studied.