Endo Pharmaceuticals Holdings Inc. said Thursday regulators want more information about its testosterone injection Aveed as they consider approving the drug for sale.
Endo said the FDA sent a complete response letter asking for details about rare but serious side effects of Aveed, including anaphylactic reactions and microembolisms. The FDA also found Endo's risk evaluation strategy was not sufficient.
Aveed is intended to be a long-lasting treatment for hypogonadism, or low levels of testosterone in men.
Outside the U.S., the injection is marketed as Nebido by Bayer Schering.
In afternoon trading, Endo shares lost 97 cents, or 4.3 percent, to $21.45.