The number of severe attacks of breathing problems was 40 percent lower for people who got the larger dose of roflumilast and 28 percent lower for those getting the smaller dose, compared to those getting a placebo.

Most cases of COPD are caused by either chronic bronchitis, a destructive inflammation of the air-carrying passages of the lungs; or emphysema, in which the tiny air sacs in the lungs that allow oxygen to enter the blood are damaged. Smoking is a leading cause of both conditions.

The new drug, roflumilast, was developed in Europe and is being tested both there and in the United States in trials designed to lead to its approval for medical use. It reduces the inflammation that is a major feature of COPD.

Lung Function Improved

The Dutch trial, the results of which are reported in the Aug. 13 issue of The Lancet, was led by lung experts at Leiden University Medical Center. They enrolled more than 1,100 COPD patients. Half were given standard treatment plus roflumilast, in two different doses, while the other half got a placebo, an inactive substance.

The trial lasted 24 weeks. Over that time, lung function, measured as the amount of air a person could expel from the lungs, improved significantly in patients who got a smaller dose of roflumilast. Those who got a larger dose reported even more improvement. There was no improvement in those who did not get the drug.

The number of severe attacks of breathing problems was 40 percent lower for people who got the larger dose of roflumilast and 28 percent lower for those getting the smaller dose, compared to those getting a placebo. And roflumilast also improved the quality of life of those who got it.

"Roflumilast is a promising candidate for anti-inflammatory COPD treatment," the researchers concluded. But, they added, "long-term studies are needed to fully assess the effect on health-related quality of life."

'Very Intriguing Concept'

Such studies are taking place in the United States and Europe, said Dr. Neil Schachter, professor of pulmonary medicine and medical director of the respiratory care department at Mount Sinai Medical Center in New York City. He is involved in one of those studies.

Anti-inflammatory drugs already are used to treat COPD, but "this [roflumilast] is a new class of agent," Schachter said. "It is very specific for a certain enzyme that is involved in smooth muscle contraction, which is one of the features of bronchospasm."

Bronchospasm is the sudden narrowing of the air tubes that causes wheezing and other breathing problems.

Dr. Klaus Rabe is lead author of the new study and chairman of the department of pulmonology at Leiden University. He said, "The principle of interfering with this pathway is a very intriguing concept." But he has concerns about the drug's possible side effects, mainly those affecting the intestinal tract.

"We were able to provide this medication at concentrations that were comfortable to the participants," Rabe said of the study, which he noted is the largest yet done.

May Slow Down Progression

The US trials "are for both COPD and asthma patients," Schachter said. "It's hoped that they will open a new class of drugs that have potential for both reducing symptoms of the diseases as well as hopefully some reversible components of the disease, so that it may slow down progression of the disease."

Schachter knows of at least two such studies, each of which is enrolling participants at a number of medical centers. The study in which he is involved has completed enrollment of patients, he said. Since such trials can run for six months or a year, results are not expected until some time next year at the earliest, he said. More information: The National Library of Medicine has more information about COPD.