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.
"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."
The study findings impress immunologist Cassian Yee, MD, of Fred Hutchinson Cancer Research Center in Seattle. And he knows what he's talking about. Yee's team is using T-cell therapy to halt cancer growth in patients with advanced melanoma. Last year, they reported that eight of 10 patients responded favorably to the treatment. Tumors stopped growing for up to a year in five of the patients; three patients had their tumors shrink.
"The Dranoff study is really good proof of principle that immune therapies can be translated from interesting lab findings into the treatment of patients," Yee tells WebMD. "This is not something that patients with lung cancer can receive immediately. Right now it takes quite a lot of lab work to modify the tumor cells for an individualized vaccine. We may in the future see several developments that will allow this to be used to treat more patients."
The Dranoff study appears in the Feb. 15 issue of the Journal of Clinical Oncology.