Gene Therapy Cures Adult Leukemia
CLL Tumors 'Blown Away' in 2 of 3 Patients Given Experimental Treatment
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.
CAR T cells appear to be a much better option. But the amazing success now reported came very early in the development of this new treatment. Only a few of the thousands of CLL patients facing death will be able to enter the still-small clinical trials testing CAR T cells.
"The distressing thing is the need will far, far, far outweigh any slots in clinical trials," Galipeau says.
But Porter says his team is energized by the early success and is pushing forward as quickly as possible. Even so, a lot of work remains to be done.
"We've treated only a very small numbers of patients," Porter says. "So part of the goal is to see these results in more people, see that the results are sustained, and that it is safe over time. We need to find the appropriate dose and to make incremental modifications. And now we have shown activity, we can try and apply it earlier in the course of the disease. We have reason to think treating patients sooner may be even safer and more effective.
Although the CAR T cells in the study were designed to fight CLL, there's good reason to hope they can be effective in other forms of cancer. The catch is that it can work only on tumor cells that carry markers flagging them for destruction. Normal cells that carry the same markers will also be destroyed.
Many cancers are known to carry such markers, and there's hope of finding more.
"We have a clinical trial at the University of Pennsylvania with an anti-mesothelin molecule [which marks mesothelioma, ovarian, and pancreatic tumors]," Porter says. "There are other trials around the country trying to target renal cell carcinoma [kidney cancer] and myeloma [skin cancer]. We are hoping to identify other tumor targets, particularly in other leukemias, to adapt this technology."
Porter, June, and colleagues report their findings in the Aug. 10 early online versions of two major journals: The New England Journal of Medicine and in Science Translational Medicine.