At the 24th Congress of the European Hematology Association (EHA), Richard Dillon from King's College, London, UK, talks to the AML Global Portal, about the impact of minimal residual disease (MRD) status on the outcomes of patients with acute myeloid leukemia (AML) undergoing allogeneic stem cell transplantation (allo-SCT).
Dr. Dillon explains that patients who have a stem cell transplant for AML, and then relapse have very poor outcomes, with fewer than 20% of patients achieving long term survival. Dr. Dillon emphasizes that there is a lot of interest trying to identify patients who are at high risk of relapse after transplant so that physicians can intervene, to try and improve survival rates.
There have been a lot of studies over the years looking at MRD pre-transplant, and when this is measured using flow cytometry. The tests have found that patients who test positive have an extremely high relapse risk. Another method used to measure MRD that Dr. Dillon explains is using Polymerase chain reaction (PCR), which was used to test 107 patients in the UK, AML-17 trial. This trial looked at patients MRD status by PCR prior to transplant, this was important because the PCR test is more sensitive than flow MRD tests.
The results of the study found that are a group of patients who MRD+ that have levels below a defined threshold, therefore identifying patients who don't need any interventions. On the other hand, Dr. Dilon and his colleagues identified another group of patients who have high levels of MRD and patients with FLT3 mutations with any level of MRD, who have extremely poor outcomes after transplant, with only 17% of survival at 2 years after transplant.
Dr. Dilion and his team were able to define a population of patients that are at high risk of relapse, which can lead physicians to test for interventions that will ultimately reduce the risk of patients relapsing.