Donor CAR T May Increase Remission in Relapsed or Refractory AML Patients
According to the American Cancer Society, there will be over 20,000 new cases of acute myeloid leukemia (AML) and about 11,540 deaths this year. As one of the most common types of leukemia, there are several treatment options available, and most who are diagnosed with the disease go into remission after receiving the initial treatment.
But patients who have not achieved a remission status after several cycles of chemotherapy are then diagnosed with refractory acute myeloid leukemia, or if the disease has returned, they are diagnosed with relapsed AML. Their chances of survival are very poor and for many patients, there are no treatment options.
Dr. David Sallman, Department of Malignant Hematology
While clinical trials have been a key option and CAR T-cell therapy has been a paradigm shift in hematologic malignancies, in particular, researchers and physicians at Moffitt Cancer Center are now looking for a breakthrough in patients with refractory and relapsed AML.
They presented a phase 1 trial during the American Society of Hematology Annual Meeting and Exposition focusing on a genetically modified allogeneic T-cell product manufactured from healthy donor cells. The product is called UCART123.
The phase 1 trial focused on evaluating the safety, tolerability, expansion and persistence of UCART123 given at escalating dose levels with lymphocyte depleting chemotherapy, a type of chemotherapy that allows CAR T cells to expand in a patient.
The CAR T cells, which come from a healthy donor, are engineered to attack a marker on the outside of the leukemia cell called CD123. They have also been engineered for safety so they do not attack other normal cells in the patient.
“The overall goal of the trial is to get AML patients in remission, potentially getting them to transplant or even in patients who relapse after transplant to give them an option in order to improve their quality and quantity of life,” said Dr. David Sallman, assistant member in the Department of Malignant Hematology at Moffitt.
The study looked at men and women with a median age of 57. Half the patients on the trial relapsed after allogeneic stem cell transplantation, and the majority of patients had adverse molecular features.
Sallman says with lymphodepleting chemotherapy including alemtuzumab, there is excellent expansion of the CAR T cells and clinical responses. Most impressively, one patient who relapsed after a transplant and was treated in the study has been in a perfect, minimal residual disease-negative complete remission for over one year.
With the trial still ongoing, protocol changes have been implemented to improve the safety of the CAR T cell, as well as to give multiple infusions with the goal to increase the number of patients who have a positive response.
