Genentech Inc. and OSI Pharmaceuticals Inc., two leading biotechnology companies, announced Monday that a combination of two cancer drugs proved to be disappointing in a late-stage trial, missing its primary goal - enhancing survival for patients suffering from lung cancer.

In the clinical trial, called BeTa Lung, Genentech's Avastin was combined with OSI's Tarceva in people with lung cancer who didn’t show positive results in chemotherapy. But the results showed no significant difference between the longevity of patients who were treated with Avastin and Tarceva and the longevity of those who were administered Tarceva and a placebo.

The results generated disappointment among those who expected the mixture of the drugs to prolong the lives of patients with lung cancer. "We are disappointed this study did not show an improvement in survival for patients with advanced lung cancer who have a poor prognosis and a disease that is extremely difficult to treat," according to Hal Barron, Genentech's development and chief medical officer.

Avastin received the U.S. Food and Drug Administration approval as a first-line treatment in combination with chemotherapy for patients without the squamous form of non-small cell lung cancer. This year, the drug was also approved for use in breast cancer.

Tarceva, approved as a second line treatment for non-small cell lung cancer and pancreatic cancer, acts by interfering with the expansion of cancer cells and by slowing their growth and spreading in the body.

Both Tarceva and Avastin are already available for treating lung cancer, a disease responsible for 1.3 million deaths each year worldwide.

Full results from the study are to be presented at the 2008 Chicago Multidisciplinary Symposium in Thoracic Oncology, which will take place on November 13-15.