An experimental vaccine wiped out lung cancer in some patients and slowed its spread in others in a small but promising study, researchers said.
Three patients injected with the vaccine, GVAX, had no recurrence of lung cancer for more than three years afterward, according to the study of 43 people with the most common form of the disease, non-small cell lung cancer.
The findings were published in the US Journal of the National Cancer Institute. The research was funded in part by CellGenesis, a pharmaceutical company that hopes to produce the vaccine.
The vaccine, developed by researchers at Baylor University Medical Centre in Dallas, is years away from reaching the market, if ever. The researchers hope to apply for Food and Drug Administration approval in three years.
"The results are very promising for patients with non-small (cell) lung cancer, which is frequently resistant to chemotherapy," said Dr John Nemunaitis, a Baylor oncologist who led the study.
Non-small cell lung cancer is the leading cause of cancer death in the US, killing more than 150,000 people each year. The disease is related to smoking and is often difficult to treat. Treatment usually involves removal of the tumour, chemotherapy or both.
The study is the first to show complete and long-lasting regression of lung cancer by stimulating the immune system to attack cancer cells, Dr Nemunaitis said. A similar approach has shown promise against skin and renal cell cancer.
In the study, each patient was injected in the arm and leg with a vaccine that included cells from his or her tumours. A gene called CM-CSF was placed into the cancer cells to change the surface of the cells to help the body identify them as cancerous. The body's immune cells soon began to recognise, attack and destroy the cancer cells in the lungs.
"The most exciting thing is in those who responded to the vaccine, it was complete," Dr Nemunaitis said. "It's given us a lot of encouragement."
AP