A U.S. health advisory panel on Thursday issued a split vote on data for Pfizer Inc's drug to treat a rare neurodegenerative disease.

The U.S. Food and Drug Administration panel voted 13 to 4 that the drug did not show that it met the main goal in a study in treating the fatal condition. However, the panel also voted 13 to 4 that the drug treated a surrogate endpoint, which may correlate with treating the underlying disease.

The panel's recommendation will be considered by the U.S. Food and Drug Administration when it takes a decision on tafamidis, a relatively minor product for the world's largest drugmaker.

FDA staff on Tuesday recommended rejecting the drug saying the data did not prove that it worked well in treating the disease.

Tafamidis, which is already approved in Europe under the name Vyndaqel, is meant to treat familial amyloid polyneuropathy, a fatal condition that affects as many as 10,000 people worldwide, including about 2,500 Americans.

Pfizer's shares closed at $22.14 on Thursday on the New York Stock Exchange.