John Nemunaitis, oncologist and researcher at the Mary Crowley Medical Research Center (MCMRC) at Baylor University Medical Center at Dallas, has developed a vaccine that suppresses lung cancer in some patients. Results of the clinical trial are published in the Journal of the National Cancer Institute in a paper titled "Phase I/II Study of Gvax in Non-Small Cell Lung Cancer (NSCLC)."
NSCLC is the leading cause of cancer death for men and women in the United States. More than 150,000 people die from the disease each year.
In Dr Nemunaitis's research trial 43 patients with early and advanced stage NSCLC were injected with the vaccine, called Gvax. Vaccines were administered every two weeks for a total of three to six vaccinations.
"While it's premature to call this a cure, we found that in a small number of people who were sensitive to this approach, the cancer hasn't come back. And, for a number of patients, it has been more than three years since they received the vaccine," said John Nemunaitis, principal investigator of the study at Baylor University Medical Center at Dallas.
Researchers developed the vaccine using cells obtained from each patient's tumour. A gene, called GM-CSF, is placed in the cancer cells to change the surface of the cells so the body can identify the cancerous cells. Once the vaccine is injected, the body's immune cells come to the injection site and work with lymphocytes, immune cells that help rid the body of an infection.
"We're trying to turn on the lymphocytes so they can identify the cancer cells and clear it, just like the body clears the cold or flu virus or an infection," Dr Nemunaitis said.
Three patients with advanced stage lung cancer experienced complete remission of their disease lasting six months, 18 months and ongoing at 22 months. For two of these patients, prior treatment with chemotherapy had failed. One patient experienced a 30-per cent decrease in size of lung nodule, and for seven patients, their disease remained stable and did not progress for a period ranging from almost five months to more than 28 months.
"These results are very promising for patients with NSCLC, which is frequently resistant to chemotherapy," Dr Nemunaitis said. "We believe this is the first time immune therapy has been the sole treatment associated with complete and durable regression of metastatic NSCLC lesions, particularly those lasting more than one year, as observed in two patients in our study."
While chemotherapy is an option for patients with advanced disease, results show a 15 to 21 per cent response rate, median survival of 7.4 to 8.2 months and one year overall survival of 31 to 36 per cent. Early-stage patients undergoing complete surgical resection have a greater than 75 per cent chance of surviving one year, but survival is reduced to 35 to 50 per cent at five years largely as a result of disease that recurs.
Baylor University Medical Center at Dallas is a leading patient care and research center for the Southwest. With more than 1,000 beds and 900 physicians on staff, Baylor is recognized by US News & World Report among America's best hospitals in a range of medical specialties. Currently at Baylor, more than 500 research protocols are under way.