This past March, a group of scientists from Memorial Sloan-Kettering Cancer Center, led by Dr. Renier Brentjens and Dr. Michel Sadelain, gave leukemia patients a ray of hope when they published findings for what could turn out to be a cure for cancer.
According to Forbes magazine, the scientists used a new type of cancer therapy that genetically modifies a patient’s T-cells on a particularly lethal form of leukemia called B-cell acute lymphoblastic leukemia, or B-ALL. The modified T-cells targeted the cancerous B cells, using a chimeric antigen receptor or CAR. The CAR was designed to attach itself to a protein called CD19. Five patients in the study saw all their cancers disappear completely in only a few weeks.
The therapy had toxic side effects that were treated with steroids. In one patient who died, the steroids destroyed the genetically modified cells. The hope is that this treatment will become a first-line treatment, rather than a therapy of last resort for patients in whom conventional therapy failed. Patients who received the treatment in the earliest stages of the disease might find it less toxic.
“We had hoped, but couldn’t have predicted that the response would be so profound and rapid,” said Brentjens.
Although CAR T-cell therapy still has some obstacles to overcome and refinements to be made, it is a promising therapy nonetheless and holds out a hope for an eventual cure of leukemia.
On a similar note, doctors at the University of Pennsylvania recently used a treatment that made the most common type of leukemia, chronic lymphocytic leukemia (CCL), completely disappear in two patients. CCL is usually treated with chemotherapy and radiation; bone marrow transplants can cure it, but there is the problem of finding a match, and the transplant doesn’t work all the time. In addition, it also brings on side effects such as pain and infection.
The Pennsylvania physicians removed certain types of white blood cells that the body uses to fight disease from the patients. Using a modified, harmless form of HIV, the virus that causes AIDS, they inserted a series of genes into the white blood cells. This made the white blood cells target and kill the cancer cells. A gene was also inserted in the white blood cells to make them multiply rapidly. The physicians described the white blood cells as acting like “serial killers,” tracking down and killing cancer cells in the blood, bone marrow and lymph tissue.
By Tanya J. Tyler, Staff Writer