SATURDAY, May 31 (HealthDay News) -- The long-awaited results of a trial of the biologic drug Erbitux on patients with advanced non-small cell lung cancer show it prolonged survival by about five weeks when combined with chemotherapy.

Medical professionals have known the drug improved survival, but the question has been by how much.

"This will give us more options to treat patients with non-small cell lung cancer, for whom the prognosis is very poor. Five-year survival is less than 5 percent," said Dr. Shakun Malik, director of the lung cancer program at Georgetown's Lombardi Comprehensive Cancer Center in Washington, D.C.

"We haven't had much happening in the treatment of lung cancer for a long time," she added. "We now have some tremendous progress being made, and most of this is from the addition of biological therapies."

"For lung cancer, a small step forward is a big step, but it's always a question - this is four or five weeks, what does that really mean?" said Dr. Karen Reckamp, an assistant professor of medicine at City of Hope Cancer Center in Duarte, Calif.

There have been other trials involving Erbitux with similar chemotherapy regimens which did not show any benefits. This is the second study that has shown an improvement, Reckamp said.

"We have other negative studies. How is this going to fit into our packet? It does show a survival benefit. The toxicities are probably relatively reasonable," Reckamp said. "I think it's a drug that, with some discussion and some careful understanding of how this trial is different, will be something we do utilize in the right patients."

Avastin (bevacizumab), which blocks blood supply to the tumor, is currently the only targeted therapy approved for this type of lung cancer. Erbitux would be the second such drug approved for this use. Erbitux is made by ImClone Systems Inc. and marketed by Merck in Europe. Merck funded the study.

Erbitux (cetuximab) affects the epidermal growth factor receptor, believed to play a role in this type of cancer. It is already approved for and used in patients with cancer of the colon and the head and neck.

The study involved 1,125 patients, almost all of whom had stage IV cancer. Participants were randomized to receive either platinum-based chemotherapy alone or chemotherapy plus Erbitux.

Those in the Erbitux group lived an average of 11.3 months vs. 10.1 months for those who received a placebo. The response rate was also better in those receiving Erbitux: 36.3 percent vs. 29.2 percent.

And unlike other targeted therapies, the benefit was seen in all subtypes of the disease, said the Austrian researchers, whose findings were released Saturday in Chicago at the annual meeting of the American Society of Clinical Oncology.

Lung cancer is the leading cause of cancer death in the United States, with roughly 30 percent of all cancer deaths linked to this type of malignancy, according to the Lung Cancer Alliance.

More information

Visit the National Cancer Institute for more on lung cancer.