Vaccine May Help Slow Spread of Lung Cancer
Experimental Vaccine Targets a Protein Linked to Many Cases of Non-Small-Cell Lung Cancer
Oct. 21, 2011 -- A cancer vaccine shows potential to slow the spread of cancer among lung cancer patients, a study shows.
The experimental vaccine targets a protein linked to more than half of all cases of non-small-cell lung cancer, the most common form of lung cancer.
The study is published in The Lancet Oncology.
The study was conducted in Europe and included 148 patients with advanced lung cancer. It was led by Elisabeth Quiox, MD, a professor of pneumonology at the Université de Strasbourg, France.
The patients were divided into two groups. Both groups received standard chemotherapy while one group received the experimental vaccine known as TG4010. The vaccine stimulates the immune system to destroy cancer cells.
The researchers hoped to stop the progression of the disease in at least 40% of the patients enrolled in the six-month study. If they reached that goal, they would consider the trial a success. To determine that, each participant underwent a CT scan every six weeks to see if the disease had spread.
At the end of the study, 32 of the 74 patients (43.2%) who had received the vaccine showed no signs of disease progression. Meanwhile, 35% of the study participants who received standard chemotherapy showed similar results.
The researchers write that the trial was a success and that the results suggest that the combination of vaccine and chemotherapy "translates to a better long-term outcome compared with a response obtained with chemotherapy alone."
The vaccine appeared to have other benefits as well. More patients in the vaccine group responded to treatment than patients who received only chemotherapy -- 41.9% compared to 28.4%. Also, for those patients who did respond to treatment, those given injections of the TG4010 vaccine had an average overall survival of 23.3 months, nearly twice that of patients in the comparison group.
Determining Who Will Benefit the Most
The researchers also discovered a potential biomarker that may allow doctors to better determine which patients are most likely to benefit from the vaccine, if it reaches the market.
According to the study, patients with a normal number of a specific type of natural killer cells did much better with the vaccine than patients with an increased number of the cells. Natural killer cells are a form of white blood cell that helps the body fight off cancer cells and cells infected with viruses.
These observations "point to the importance of patients' biological status as a predictor for success of therapeutic vaccination, and suggest that analysis of biological parameters should be part of the clinical developments in cancer immunotherapy," the researchers write.
This is a very important point, says Harry Raftopoulos, MD, an oncologist at the Monter Cancer Center in Lake Success, N.Y., who reviewed the study for WebMD.