Merck & Co's bid to get approval for sugammadex in the USA will have to wait a bit longer as regulators need more time to evaluate the anaesthesia compound.

The US Food and Drug Administration has notified Merck that it will take an additional three months to review the New Drug Application resubmission for sugammadex. The agency originally rejected sugammadex in August 2008 and requested additional data related to allergic reactions and bleeding events.

The rejection surprised observers at the time given that an FDA advisory committee had earlier given a unanimous recommendation for approval for sugammadex. The latter was developed by Schering-Plough which was acquired by Merck in 2009.

Merck provided the requested information on the drug and it expects the FDA’s review to be completed in the second half of 2013. Sugammadex, which was approved in Europe in 2008 where it is marketed as Bridion,  reverses neuromuscular blockade and is designed to work by inactivating rocuronium or vecuronium, ie reversing the effects of anaesthesia after surgery.

A US approval would provide a boost to sales of Bridion which brought in $261 million last year.