The Food and Drug Administration (FDA) decided not to approve the new gout medication pegloticase (Krystexxa), according to a press release issued by the drug’s manufacturer, Savient Pharmaceuticals.

Pegloticase is an enzyme, given by intravenous infusion, which breaks down uric acid so that it can be safely excreted by the body.

If too much uric acid accumulates, it can form needle-like crystals that deposit in the joints and other organs causing severe pain, inflammation and hard lumps called tophi.

Savient had asked the FDA to green light pegloticase for the 100,000 or so people in the U.S. who live with a severe form of gout that generally does not respond to other treatments. In June, a panel of experts commissioned by the FDA voted 14 to 1 in favor of granting the drug’s approval.

But the company said that regulators had concerns about proposed changes to the drug’s manufacturing process and that they had asked for more information about the company’s plans to monitor the medication's safety.