Tumor Vaccine Mops Up Lung Cancer
Vaccine Sics Immune System on Metastatic Cancers
Feb. 13, 2003 -- Vaccines made from patients' own tumors are safe and seem to work in early human tests. Future enhancements promise to make this a powerful new treatment for deadly cancers.
One reason tumors grow out of control is that T-cells -- which orchestrate immune system attacks -- ignore them. But it's possible to get their attention, say Glenn Dranoff, MD, and colleagues at Boston's Dana Farber Cancer Institute. Dranoff's team developed a vaccine that tells T-cells to target tumors.
In a pilot study, the researchers treated 35 patients whose non-small-cell lung cancers were spreading despite chemotherapy and/or radiation therapy. Tumors removed from their lungs during surgery were ground up into individual cells. The cells were then bioengineered to make a T-cell alerting chemical signal. Patients got injections of this vaccine once or twice a week.
"This is the first concerted effort to make vaccines against lung cancer," Dranoff tells WebMD. "This initial phase I study shows the approach is feasible. It does involve making patient-specific vaccines. And it is very well tolerated. In contrast to conventional treatments for cancer, there were only very minor reactions. This study shows that the immune response against lung-cancer cells can be improved through a vaccine strategy. And there is the suggestion of some encouraging clinical findings in a minority of patients."
Encouraging indeed. For two patients, surgery successfully removed their lung tumors. More than three and a half years after vaccine treatment, they remain cancer free. Five other patients had stable disease for 33, 19, 12, 10, and three months after vaccine treatment. Antitumor immune responses were seen in 18 of 22 patients. Nine of the patients had to leave the study early because of rapid disease progression.
Cell Genesys Inc., in Foster City, Calif., is developing the vaccine as a cancer treatment. The company is sponsoring phase II safety/efficacy clinical trials.
"As a single agent, this approach would be potentially much more useful in patients in the early stages of lung cancer," Dranoff notes. "It might be considered for testing in lung-cancer patients after their original tumor is removed. In the setting of advanced disease, we are going to examine vaccination in combination with other treatments."