A U.S. advisory panel backed cancer drugs by Pfizer Inc and Novartis AG for treating a rare kind of pancreatic cancer that has few treatment options.
The panel unanimously voted on Tuesday for Novartis' Afinitor and said that, while the drug had serious side effects, the potential benefits for patients suffering from the rare cancer outweighed the risks.
Pfizer's Sutent also won backing from the panel, which voted 8-2 in favor, but several panelists recommended further trials to clearly establish the drug's efficacy in treating pancreatic neuroendocrine tumors.
Both drugs are already approved for other uses and approval for the new cancer type is not expected to add hugely to sales.
Also, since the drugs are already available physicians can prescribe them for this cancer, but regulatory approval would let the drugmakers market them for the new uses.
"Pancreatic neuroendocrine tumor is a relatively rare cancer representing about $100 million of peak sales potential, less than 1 percent to Novartis' core earnings per share," Deutsche Bank analyst Tim Race said.
He said Novartis' Afinitor could see sales of about $2 billion from other indications, including breast, gastric and liver cancers.
Afinitor is already approved for treating kidney cancer and is expected to rake in $1.3 billion in 2015, according to a Thomson Reuters forecast.
Pancreatic neuroendocrine tumors are rare, with a strike rate of about 0.32 case per 100,000 people. They usually grow more slowly than other pancreatic cancers that kill within months of diagnosis.
The panel suggested the serious side effects seen with Afinitor be addressed on the drug's label, but Pfizer received a stronger message.
The panelists expressed concerns about Pfizer's decision to stop the trial before the timeline was completed and said the early halt made it difficult to measure the extent of the drug's actual efficacy.
However, panelists backed the drug given the lack of treatment options for the rare type of pancreatic cancer and the early signs of benefit shown by Sutent in the study.
While a positive panel vote does not always lead to regulatory approval of a drug, the FDA usually follows panel recommendations.
Morningstar analyst Damien Conover expects the FDA to ask for post-approval studies that can establish the drug's benefits. He does not expect to see the FDA holding up approval for lack of better study data.
The panel's backing for Sutent came after FDA staff said last Friday an early end to a study of the drug in pancreatic cancer patients might have led to an overestimation of its effectiveness.
The FDA also noted there was no significant improvement in the overall survival of patients, while a higher frequency of common side effects was recorded.
The drug, also known as sunitinib, is already approved for advanced kidney cancer and gastrointestinal stromal tumors and brings in more than $1 billion in annual sales.
Pfizer has been trying to expand the use of Sutent after it failed to prove its efficacy in breast and prostate cancer studies earlier and also faced a setback in liver cancer studies last year.