Gene Therapy Cures Adult Leukemia
CLL Tumors 'Blown Away' in 2 of 3 Patients Given Experimental Treatment
CLL Patient Describes CAR T-Cell Treatment
The treatment was not a walk in the park for patients. One of the three patients became so ill from the treatment that steroids were needed to relieve his symptoms. The steroid rescue may be why this patient had only a partial remission.
"Those engineered T cells don't hug the cells to death. They release an array of substances, nasty things that have evolved to clear virus- infected cells from your body," Galipeau says. "But now they are using this to melt down a couple of pounds worth of tumor burden, you will get some side effects."
One of the patients, whose case is reported in the New England Journal of Medicine, described his experience in a University of Pennsylvania news release. The patient chose not to identify himself by name, although he discloses that he has a scientific background. He was diagnosed with CLL at age 50; 13 years later his treatment was failing. Facing a bone-marrow transplant, he jumped at the chance to enter Porter's clinical trial of CAR T cells.
"It took less than two minutes to infuse the cells and I felt fine afterward. However, that fine feeling changed dramatically less than two weeks later when I woke up one morning with chills and a fever," he says. "I was sure the war was on. I was sure the CLL cells were dying."
A week later the patient was still in the hospital when Porter brought him the news that the CLL cells had disappeared from his blood.
"It was working and I was winning," the patient says. "It was another week later that I got the news that my bone marrow was completely free of detectable disease. It has been almost a year since I entered the clinical trial. I'm healthy and still in remission."
Is he cured? Doctors hate to declare a cure until patients have been cancer-free for at least five years. But there are signs the CAR-T cells persist in patients' immune memory, ready to mop up any CLL cells that reappear.
And there's a big downside. The CAR T cells that fight CLL also kill off normal B lymphocytes. These are the cells that the body needs to make infection-fighting antibodies.
As long as the CAR T cells persist -- which may be for the rest of patients' lives -- patients will require regular infusions of immune globulin.
Hope for Cancer Patients, but Treatment Years Away
CLL is the second most common form of adult leukemia. In the U.S. there are about 15,000 new cases and about 4,400 deaths each year.
Cure is possible, but it requires a risky bone marrow transplant. About 20% of patients don't survive this treatment -- and even when they do, there's only a 50-50 chance of a cure.