Merck & Co announced on Tuesday that the U.S Food and Drug Administration postponed their application to sell sugammadex, an injection which can reverse the effects of anesthesia during surgeries. The federal agency said they need more time to review the drug.

The announcement was released after FDA canceled a meeting last Thursday which was supposed to be the meeting that will let the advisers vote whether to approve the drug or not. The agency refused to explain the cancelation of the meeting, Reuters Health reported.

However, Merck said that the FDA informed them that it needs more time to evaluate the results of the clinical trial performed on the drug to ensure that it will not produce any allergic reactions to the patients once administered during the surgery.

The FDA rejected Merck’s application in 2008 because of reports that it had caused allergic reactions and bleeding to some patients involved in the clinical trial. The new application was supposed to prove that the reformulated drug had effectively reduced the incidents of allergic reaction based on their study performed in the United States, the Netherlands, the United Kingdom and Germany.

Dr. Glenn Murphy, an anesthesiologist and director of clinical research at North Shore University Health System in Evanston, Illinois, and also an adviser of Merck, was surprised with the cancellation of the meeting. The team were expecting that they would finally receive approval for sugammadex.

Sugammadex, with brand name Bridion, is already available in over 50 countries and had generated $261 million sales in 2012. Business analysts projected that the sales amount may reach $663 million once approved in the U.S.

The canceled meeting is another stumbling block for Merck. Two weeks ago, FDA rejected the company’s application for their insomnia drug suvorexant because of its strong dose.