NEW YORK, U.S. – Scientists report the first clear success of gene therapy in the fight against leukemia, a treatment that has transformed the patient’s blood cells missiles able to identify and destroy cancer cells.
Only three patients have been treated so far, but the results are striking: both seem free of cancer one year after the end of treatment, while the third has shown a partial response to therapy. Researchers are now considering using the same approach to attack other cancers.
“It worked very well. We have been surprised by the effectiveness, said Dr. Carl June, a gene therapy expert at the University of Pennsylvania. One year has passed. You have to see how long the remissions will last. ”
Dr. June is the lead author of the study published in the pages of The New England Journal of Medicine and Science Translational Medicine on Wednesday.
The three patients were men with an advanced form of chronic lymphocytic leukemia. The only hope of recovery is currently a bone marrow transplant or stem cells, but treatment does not always work and has a high risk of death.
Researchers have long struggled to find a way to multiply the capacity of the immune system to fight against cancer. Previous attempts to genetically modify T cells, which are found in the blood, have had only limited success, the modified cells were not reproducing well and disappeared quickly.
Dr. June and his colleagues modified the technique by which new genes are injected into T cells. The new cells created have not only focused and destroys cancer cells but they also continued to attack cancer cells that were forming. We already knew that T cells destroy viruses that way but it’s the first time this has happened against cancer cells.
The three patients have received millions of T cells modified. One of them, a man of 64, felt nothing for two weeks before reporting chills, nausea and fever. He and the other two patients were feeling what happens when large amounts of cancer cells die at the same time – a sign that the gene therapy worked.
“It was like the worst flu of their lives, said Dr. June. But after that, it’s over. They’re fine. ”
The most important side effect seems to be the destruction of certain cells that fight infection. Patients receive a monthly salary for this problem.
Researchers at the University of Pennsylvania now want to test the effectiveness of treatment against cancer similar to leukemia, as well as pancreatic and ovarian cancer. Scientists from other institutions are interested in prostate cancer and brain.
Experts are now waiting to see how the condition of three patients will evolve over the coming years.