Improving Smoking-Caused Lung Damage In Former Smokers
Iloprost, a drug used regularly to treat high blood pressure in the lungs, significantly improves lung damage in former smokers, according to results of a multicenter Phase II clinical trial led by the University of Colorado Cancer Center.
The study results were presented at the International Association for the Study of Lung Cancer meeting in San Francisco.
The researchers examined lung biopsies of 152 people who had smoked at least 20 pack-years—equivalent to one pack a day for 20 years—before and after six months of treatment with either oral iloprost or placebo.
None of the 82 current smokers who entered the trial saw significant improvement in the signs of lung disease, but former smokers treated with iloprost showed significant improvement.
“These results are exciting because they show we can actually keep former smokers from developing lung cancer with a drug that has been used routinely for other problems,” said the study’s principal investigator, Dr. Robert Keith, associate professor of pulmonary medicine at the University of Colorado Denver School of Medicine and associate chief of staff for research at the Denver Veterans Administration Medical Center.
Iloprost is commonly used to treat high blood pressure in the lungs, called pulmonary hypertension. It is similar to a body chemical called prostacyclin which widens blood vessels to lessen blood pressure.
The project started at the University of Colorado Cancer Center Lung Cancer Specialized Program of Research Excellence. In 1997, while doing animal work with prostacyclin in pulmonary hypertension, Keith and his UCCC research collaborators realized that the mice did not develop lung cancer.
“We then looked at tumor tissue and learned that if you have the enzyme that makes prostacyclin and have lung cancer, you live longer,” Keith said. “We have also learned that prostacyclin helps prevent tumors from creating new blood vessels and prevents cells from dividing abnormally. We tested iloprost in animal models, and after showing that animals were protected from developing cancer, we moved the drug into human trials.”
Keith said the next step is to test the drug in a bigger, Phase III study, to determine exactly who will benefit most from taking the drug.
Lung cancer is the No. 1 cancer killer of men and women. The National Cancer Institute estimates more than 219,000 Americans will be diagnosed with lung cancer in 2009, and more than 159,000 will die from the disease. There is no confirmed early detection test for lung cancer.