After a study disclosed that the drug Tarceva was efficient in prolonging lung cancer survival when taken immediately after chemotherapy, shares of OSI Pharmaceuticals Inc. rose fantastically.

Shares of the pharmaceutical company, based in Long Island, rose $5.25, or 15 percent, to $40.39 at 4 p.m. in afternoon trading. The stock has traded between $32.10 and $53.71 over the last year.

“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.

OSI Pharmaceuticals shares revenue from Tarceva with Genentech Inc., a leading biotechnology corporation that develops drugs to address significant unmet medical needs. Besides, Tarceva’s manufacturer received royalties from Roche Holding AG. All three companies said Friday the latest clinical trial on the once-daily Tarceva stopped the spread of advanced non-small cell lung cancer for considerably longer than a placebo, provided it is taken after treatment with chemotherapy.

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. The drug is already available for treating lung cancer, a disease responsible for 1.3 million deaths each year worldwide.

About a month ago, Genentech and OSI announced that a combination of Tarceva and Avastin, another cancer drug, proved to be disappointing in a late-stage trial, missing its primary goal - enhancing survival for patients suffering from lung cancer.