Amag Pharmaceuticals plunged in trading before markets opened Wednesday after the specialty drugmaker said regulators rejected its appeal for the expanded use of its anemia treatment.
The Waltham, Mass., company is seeking approval to use Ferahemethe, an intravenous drug, in all adult, iron deficiency anemia patients who cannot tolerate an oral iron treatment. The Food and Drug Administration approved the treatment, also known as ferumoxytol, in 2009 for use in patients with chronic kidney disease.
The drug accounts for most of Amag's revenue. The company said last week that it expects U.S. revenue from Ferahemethe to total as much as $71.5 million in 2013. Japanese drugmaker Takeda Pharmaceutical sells the drug in Canada, the European Union and Switzerland.
The FDA told Amag that it had not provided enough information to permit expanded use. The agency suggested that the company gather more clinical trial data, and it also proposed looking at alternative doses of Feraheme.
The company plans to speak with the FDA before determining what it will do next.
Shares of Amag Pharmaceuticals Inc. dropped more than 16 percent, or $3.59, to $18.27 in premarket trading.