Novartis AG said Thursday that the U.S. Food and Drug Administration approved its drug Afinitor for treating patients with advanced neuroendocrine tumors originating in the pancreas.

The approval was based on data from a drug trial that showed Afinitor more than doubled the time patients went without tumor growth. It also was found to reduce the risk of cancer progression by 65 percent compared with patients taking placebo, the company said.

The FDA determined that the safety and effectiveness of the drug in treatment of patients with carcinoid tumors was not established, however.

The move represents the first approval of a treatment for this condition in the U.S. in nearly 30 years, the drugmaker said.

Afinitor is already approved as a treatment for advanced kidney cancer and a type of a rare genetic disorder called tuberous sclerosis, which causes tumors in the brain, eyes, lungs, liver and other organs. The drug had sales of $243 million in the U.S. in 2010.

Neuroendocrine tumors, or NET, are mostly found in the pancreas, gastrointestinal tract or lungs. There are currently limited treatment options for patients with the disease. When pancreatic NET becomes advanced, meaning the cancer has spread to other parts of the body, it is considered aggressive and difficult to treat.

About 60 percent of pancreatic NET patients are diagnosed with advanced disease, and the five-year survival rate for these patients is 27 percent, Switzerland-based Novartis said.

Afinitor tablets, taken once a day, target mTOR, a protein that regulates the growth of tumor cells and the blood vessels that feed them.

"With this approval, U.S. physicians can now offer their patients with progressive pancreatic NET a new treatment helping to fulfill a critical unmet need," said Herve Hoppenot, president of Novartis Oncology.