Researchers from Boston's Dana Farber Cancer Institute, led by Glenn Dranoff, MD,have reported in the February issue of the Journal of Clinical Oncology that vaccines made from patients' own tumors are safe and future enhancements could make them a powerful new treatment for deadly cancers. Researchers claim that the tumors grow out of control when the T-cells -- which orchestrate immune system attacks -- ignore them. In the new study researchers have developed a vaccine that gets the attention of the T-cells and makes them target the 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.
Lead researcher Dranoff said that this is the first time a vaccine has been developed against lung cancer and the phase I study showed positive results. The patient specific vaccine produced very minor reactions in contrast to conventional treatments for cancer. There was also the suggestion of some encouraging clinical findings in a minority of patients. For two patients, after successful surgical removal of the lung tumors, after three and half years of vaccine treatment, they remained cancer free. Five other patients had stable disease for 33, 19, 12, 10, and three months after vaccine treatment. Anti-tumor immune responses were seen in 18 of 22 patients. Nine of the patients had to leave the study early because of rapid disease progression. Dranoff said that the vaccine, as a single agent approach, would be potentially much more useful in patients in the early stages of lung cancer. 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.
Immunologist Cassian Yee, MD, of Fred Hutchinson Cancer Research Center in Seattle , whose team used T-cell therapy to halt cancer growth in patients with advanced melanoma, appreciated the study and said that though the treatment may not be available immediately to patients, the study is really good proof of principle that immune therapies can be translated from interesting lab findings into the treatment of patients.
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.