Adding a little extra chemotherapy after finishing the initial course helped advanced lung cancer patients live longer without having their tumors grow or come back, researchers reported.

Patients with advanced lung cancer who took Eli Lilly and Co's  Alimta after finishing their normal course of chemotherapy lived cancer-free for two months or 40 percent longer than patients who took a placebo.

The preliminary results released ahead of the annual meeting of the American Society of Clinical Oncology (ASCO) suggest that adding extra months of chemotherapy after a patient has finished the initial course, and before any tumors begin to come back, may help many live longer, doctors said.

As so-called progression-free survival translates into fewer symptoms, this could mean a significant benefit to the quality of life for lung cancer patients, experts said.

"This is the first study to show that lung cancer patients can benefit from maintenance therapy," said Dr Tudor Ciuleanu of the Iuliu Hatieganu University of Medicine and Pharmacy in Romania who led the study.

Ciuleanu's team is continuing the study to see whether adding Alimta, known generically as pemetrexed, helps overall survival as well.

Alimta is approved for a lung tumor called mesothelioma and also as a second-line treatment after progression for non-small-cell lung cancer.

As a result it is usually not prescribed for lung cancer until the tumors begin to come back. The study -- released as ASCO published summaries of studies to be discussed in detail at its annual meeting later this month -- suggests more patients might get Alimta even before their tumors start to come back.

That could mean many people. Lung cancer kills 1.3 million globally and the American Cancer Society says lung cancer was diagnosed in 213,380 people in the United States in 2007, killing 160,390.

Only 15 percent of lung cancer patients are alive five years after their diagnosis because the cancer is usually advanced by the time it is detected.

Ciuleanu's team studied 663 patients with stage 3 or 4 non-small-cell lung cancer who had already received a platinum-containing drug such as cisplatin or carboplatin. Of them, 441 were randomly given Alimta infusions and 222 patients got a placebo.

The Alimta patients enjoyed more than four months free of any tumor growth or return, compared to 2.6 months for those who got a placebo, Ciuleanu said. Full details will be released June 2 at the meeting in Chicago.

Overall, the patients given Alimta lived an average of 13 months compared to 10 months for the placebo group, but this data is not final, Ciuleanu said.

The people who got placebos did not get any more treatment so it is unclear whether it was just getting any kind of chemo, or whether the Alimta had an effect that older chemotherapy drugs would not have had.

"Would one find similar results by giving another active anti-cancer drug after the initial period of chemotherapy, or would one find results by simply continuing chemo?" Dr. Richard Schilsky of the University of Chicago and president-elect of ASCO asked in a telephone briefing.

 "I think these are questions that we can't answer from the current data but would be interesting to think about."    

Analysts said the new indications could add $1 billion to Alimta's market. "We believe the market opportunity for Alimta is substantial, offering potential upside versus our 2012 forecast of $1.7 billion," said Leerink Swann analyst Seamus Fernandez. - Reuters