Genetically altered immune cells wiped out tumors in two men with a deadly form of skin cancer and kept the patients disease-free for at least 18 months, US scientists said.
Dr Steven Rosenberg
Fifteen patients did not respond to the treatment, however, and the researchers and other experts said more work was needed to make it more effective.
Still, the findings were welcomed as evidence that cancer patients can be successfully treated using gene therapy, a troubled field that has been hindered by safety concerns. Scientists voiced hope the approach could work for other cancers.
In the new study, researchers at the National Cancer Institute (NCI) infused 17 advanced melanoma patients with their own white blood cells that had been removed and genetically engineered to fight tumors. The cancer was eliminated in two male patients, the researchers said.
Before the experiment, the patients had advanced skin cancer that was not helped by standard therapies and they were expected to live just three to six months, Dr Steven Rosenberg, chief of surgery at the NCI, said.
Writing in Science, the researchers said the white blood cells had been armed with genes to spark production of proteins called T-cell receptors. Those receptors recognised molecules on the melanoma cells and directed the white blood cells to destroy the cancer, they said.