About 60 percent of patients who have a stem cell transplant experience a complication called graft-versus-host disease (GVHD), in which T cells (white blood cells) from the donor attack tissues of the recipient. Symptoms of GVHD include rash, digestive problems, weight loss, and liver problems. Removing T cells from the stem cell donation can reduce the risk of GVHD, but it also increases the amount of time it takes for the recipient’s immune system to recover after the transplant.
In this study, researchers are seeking to find the best dose of specially modified T cells that can be given to patients with hematologic cancers who are receiving a stem cell transplant from a partially matched relative. The T cells from the donor are removed, sent to a laboratory, and given a gene that will make them react to an investigational drug called AP1903, which can turn off their ability to cause GVHD.
The modified T cells, now called BPX-501, are given to the patient with the stem cell transplant. If the patient develops GVHD, he/she can receive AP1903, which will activate a “turn-off” switch and make the BPX-501 T cells stop working. This could be a novel approach to enhancing immune system recovery after stem cell transplantation while reducing the risks associated with GVHD.