Tarceva’s manufacturers, Genetech Inc and OSI Pharmaceuticals, said the drug proved its effectiveness in stemming the progress of lung cancer.

889 patients at 160 lung cancer treatment centers worldwide took part in a new study, called Saturn (SequentiAl Tarceva in UnResectable NSCLC). They were given Tarceva after no less than four cycles of standard chemotherapy. The findings showed that the drug was effective in reducing lung cancer, as the two companies happily announced.

“Tarceva remains our core assetand principal source of revenue, and we were really pleased to see the study results,” said Colin Goddard, OSI's chief executive officer.

Approved as a second line treatment for non-small cell lung cancer and pancreatic cancer, Tarceva interferes with the expansion of cancer cells and by slowing their growth and spreading in the body. The drug is already available for treating lung cancer, the most common cause of cancer mortality worldwide, a disease that accounts for 1.3 million deaths each year.

In the face of performing well in this clinical trial, the findings of another study that involved Tarceva were disappointing. In a late-stage trial, a combination of Tarceva and another cancer drug, Avastin, didn’t prolong life of patients diagnosed with lung cancer. However, if administered immediately after chemotherapy, Tarceva is now thought to open “a new treatment option for advanced lung cancer patients,” as Vontobel analyst Andrew Weiss said.

Shares of OSI Pharmaceuticals rose $5.25, or 15 percent, to $40.39 at 4 p.m. in afternoon trading two days ago. The stock has traded between $32.10 and $53.71 over the last year, the media reported.