A key study looking at adding the lung-cancer drug Tarceva to Avastin showed the product helped delay the advancement of the disease while a separate study showed that continuing initial treatment with Alimta helped prolong survival in patients with advanced non-small cell lung cancer.

The studies are scheduled to be presented this weekend at the American Society of Clinical Oncology's annual meeting.

Both Alimta, sold by Eli Lilly & Co. (LLY), and Tarceva, sold in the U.S. by Roche's (RHHBY) Genentech and OSI Pharmaceuticals (OSIP) were being studied as maintenance therapy in patients with advanced lung cancer, a relatively new concept of continuing treatment with some drugs after initial chemotherapy but before new tumor growth, which is when additional treatments would typically be started.

In a study known as ATLAS, Tarceva, a pill designed to block a protein involved in tumor growth, was given to some patients who had already been treated with four cycles of chemotherapy in addition to being treated with Avastin. Avastin, another drug by Roche's Genentech unit, is designed to block blood vessels that are involved in tumor growth.

In the study more than 700 patients were randomized to receive Avastin plus a placebo, or fake pill, or Avastin in combination with Tarceva.

The study showed patients in the Tarceva group had a longer time before the cancer started growing again. Median progression-free survival was 4.8 months for patients who received Tarceva and Avastin compared to 3.7 months for patients in the Avastin group, which translated into a 29% reduced risk of disease progression.

The study showed a higher rate of side effects in patients receiving Tarceva and Avastin, including rash diarrhea, high blood pressure and fatique. There were eight deaths associated with adverse events in the group of patients treated with Avastin plus Tarceva, compared with four in the Avastin plus placebo group.

Avastin is currently approved to treat lung cancer in combination with two types of chemotherapy drugs while Tarceva is approved for use in patients who failed treatment with at least one type of chemotherapy. Chemo kills cancer cells but can also kill healthy cells.

The other study involving Alimta, which many doctors consider a less toxic form of chemotherapy, showed continuing treatment with the drug prolonged overall survival, which the ultimate measure of a drug benefit. Last year data from the same study showed it prolonged the time before lung cancer started progressing.

Alimta is currently approved as a first-line treatment for advanced non-small cell lung cancer in combination with the chemotherapy agent cisplatin and as a single agent in patients with recurrent disease.

The study involved nearly 700 patients who had been previously treated with four cycles of chemotherapy including Alimta. In 441 patients maintenance treatment with Alimta was continued until the disease progressed while 222 patients were given a placebo or fake drug.

The study showed patients who received Alimta lived for an average of 13.4 months compared to 10.6 months for patients in the placebo group. The study showed patients receiving Alimta had more side effects including fatigue and low white blood cell counts than those in the placebo group.

Most people with lung cancer are diagnosed with advanced stage disease that cannot be surgically removed or has spread to other parts of the body. The majority of people with advanced lung cancer survive less than one year.

Lung cancer is the largest cause of cancer death among men and women in the U.S. and approximately 160,000 Americans will die from the disease in 2009. Non-small cell lung cancer is the most common form of the disease.

-By Jennifer Corbett Dooren, Dow Jones Newswires; 202-862-9294; jennifer.corbett@dowjones.com