T-Cell Therapy Puts Leukemia Patients in Extended Remission
An experimental therapy has brought prolonged remissions to a high proportion of patients who were facing death from advanced leukemia after standard treatments had failed, researchers are reporting.
The therapy involves genetically programming cells from the patient’s own immune system to fight the disease.
The research included thirty patients: five adults ages twenty six to 60, and twenty five children and youthfull adults ages five to 22. All were severely ill, with acute lymphoblastic leukemia, and had relapsed several times or had never responded to typical therapies. In more than half, the disease had come back even after a stem-cell transplant, which usually gives patients the best hope of surviving. Their life expectancy was a few months, or in some cases just weeks.
Six months after being treated, twenty three of the thirty patients were still alive, and nineteen of them have remained in accomplish remission.
The explore, by researchers at the Children’s Hospital of Philadelphia and the Hospital of the University of Pennsylvania, is being published in The Fresh England Journal of Medicine.
“We have a number of patients who are a year or more out and are in remission and not requiring other therapies,” said Dr. Stephan A. Grupp, who led the part of the explore done at Children’s Hospital of Philadelphia. He said those long remissions gave the researchers hope that the treatment would have lasting effects.
Earlier reports by the same researchers involved only a handful of patients, some with chronic rather than acute leukemia. The scientists say the growing number of patients treated helps demonstrate that the findings are real.
“With the initial patients, we didn’t know if it was just fortunate,” said Dr. Carl H. June, the director of translational research at the university’s cancer center. “It turns out it’s reproducible.”
He and Dr. Grupp said that other hospitals around the country would soon test the experimental treatment in children with advanced acute lymphoblastic leukemia.
Similar research, also with encouraging results, is being done at other centers, including the National Cancer Institute and Memorial Sloan Kettering Cancer Center in Fresh York.
Each year in the United States, acute lymphoblastic leukemia affects about Two,400 people older than 20, and Trio,600 junior. It has a cure rate in adults of only about forty percent, compared with eighty percent to ninety percent in children. About 1,170 adults die from the disease each year, compared with two hundred seventy people under age 20.
The experimental treatment uses patients’ own T-cells, a type of immune cell. Researchers extract the T-cells and then genetically engineer them, using a disabled virus to slip fresh genetic material into the cells. The fresh genetic material reprograms the T-cells to recognize and kill any cell that carries a particular protein on its surface. Then the cells are dripped back into the patient, like a transfusion.
The cells are also programmed to multiply, so that each one can yield as many as Ten,000 more cancer-killing cells.
The protein they search for, called CD19, is found on B-cells, which are also part of the immune system. It was chosen as the target because these patients have a type of leukemia that affects B-cells, so the aim is to train the patients’ T-cells to ruin B-cells. Healthy B-cells — which make antibodies to fight infection — are killed along with cancerous ones, but that side effect is treatable.
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The treatment clearly does not work for everyone. Seven of the thirty patients died, including a few who had accomplish remissions at very first and then relapsed. In three, the leukemia came roaring back in B-cells that lacked the target protein and therefore were not vulnerable to the treatment.
Even so, Dr. June described the effectiveness of the treatment as “beyond my expectations.”
Of the nineteen patients who stayed in remission, fifteen did so without any extra treatment. One of them is Emma Whitehead, now 9, who was treated more than two years ago.
Some researchers have thought that, to be on the safe side, any patient who went into remission after T-cell treatment should have a stem cell transplant, because stem cells are considered the standard of care for this type of leukemia. But Dr. June and Dr. Grupp said the long remissions suggested that transplants might not be needed. They hope that eventually the T-cell treatment will be used instead of stem cell transplants, which are risky and arduous.
But the T-cell treatment has its own side effects, in particular a phenomenon known as cytokine release syndrome. It occurs when the T-cells churn out hormones called cytokines that can cause fever, aches, drops in blood pressure and breathing trouble. The more cancer there is to demolish, the worse the syndrome, Dr. June said.
Dawn Carie, from Chesterfield, Mich., said her daughter, Lexie, then 16, had the T-cell treatment a year ago, after numerous types of chemotherapy and a stem-cell transplant had failed. Within hours of receiving the T-cells, Lexie’s temperature shot up to one hundred five degrees, and she became disoriented and had scaring hallucinations. But when it was all over, she was in remission. For the very first time since Lexie was Two, her mother said, tests found no signs whatsoever of leukemic cells.
Because her disease had been so severe, Lexie had two more infusions of T-cells a few months after the very first one. She remains in remission.
Lexie is now a senior in high school, busy applying to colleges, Ms. Carie said, adding, “You know, it’s odd to feel normal, because we indeed never have.”
In July, the Food and Drug Administration designated the T-cell treatment a “breakthrough therapy” for relapsed and treatment-resistant acute lymphoblastic leukemia in adults and children. The designation recognizes experimental drugs “that may demonstrate substantial improvement over existing therapies” for life-threatening conditions, and is meant to speed their development and review.
Presently, the patients’ T-cells are processed at the University of Pennsylvania. But the drug company Novartis, which helped pay for the probe, has invested strenuously in the research, holds licenses to the technology and is expected to take over the cell processing. Dr. June, Dr. Grupp and some of the other probe authors developed the technologies and may profit from them.
A version of this article emerges in print on October 16, 2014, on Page A15 of the Fresh York edition with the headline: T-Cell Therapy Puts Leukemia Patients in Extended Remission. Order Reprints | Today’s Paper | Subscribe
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