The US Food and Drug Administration has again refused to approve Bridion (sugammadex), Merck’s investigational medicine used to reverse neuromuscular blockade brought on by rocuronium or vecuronium in general anaesthetics.
The FDA’s decision has been announced by Merck, which received a complete response letter from the agency concerning sugammadex’s resubmitted new drug application.
The agency originally refused to approve the drug in 2008, citing allergic reactions and bleeding in some patients.
The new letter to Merck expressed concerns about operational aspects of a hypersensitivity study that the FDA requested in 2008.
Merck said it was examining the letter and is seeking to work out a forward path for the drug in the ‘very near future’.
Sugammadex is approved for use in 50 countries outside the US, and the company has noted that more than five million vials have been sold as of June 2013.
The FDA cancelled a discussion of sugammadex at a meeting of the Anesthetic and Analgesic Drug Products Advisory Committee (AADPAC) in July, saying it needed more time to assess the results of an inspection it carried out at a clinical trial site conducting the hypersensitivity study.
Merck Research Laboratories head of global neuroscience clinical development David Michelson said: "We believe sugammadex is an important innovation, and will work closely with the FDA to bring this product to hospitals, surgeons, anesthesia professionals and patients in the United States."
Neuromuscular blockade is used in anaesthetics to induce muscle relaxation during surgery, and sugammadex is designed to reverse the state by directly inactivating rocuronium or vecuronium through encapsulation.