Merck Says FDA Needs More Time for Post-Surgery Drug Review

July 16, 2013

(Reuters) - Merck & Co Inc said on Tuesday that U.S. health regulators need more time to review its application to sell sugammadex, an injection designed to reverse the effects of muscle relaxants used during surgery.

The announcement came after the U.S. Food and Drug Administration canceled a meeting of outside advisers that had been set for Thursday. Merck said the FDA said it needed additional time to assess the results of its recently completed inspection of one of the company's clinical trial sites.

In 2008 the FDA declined to approve sugammadex, citing concerns about its possible association with allergic reactions and bleeding.

The advisory panel was supposed to discuss Merck's revised application, which the company says includes data showing the drug slightly increases the risk of allergic reactions but does not increase the risk of bleeding.

Merck said the site the FDA is still evaluating was one of four involved in its latest trial to test the drug's potential to cause allergic reactions. Merck said the site is not in China, a country drugmakers are increasingly using to conduct clinical trials, but declined to give further details.

Muscle relaxants are typically used at the beginning of an operation to facilitate the introduction of a breathing tube. They can also be used during abdominal and certain other procedures to prevent muscle movements that could complicate surgery.

Sugammadex is the first in a new class of drugs designed to reverse the effect of the muscle relaxants rocuronium and vecuronium. Merck acquired sugammadex when it bought Schering-Plough for $41 billion in 2009.

Sugammadex is already approved in more than 50 countries, where it is sold under the brand name Bridion. It generated worldwide sales of $261 million in 2012.

Analysts on average forecast U.S. sales of sugammadex, if ultimately approved, to reach $663 million annually by 2018, according to Reuters data. It would compete with Valeant Pharmaceuticals International Inc's Prostigmin, known generically as neostigmine, and Tensilon, also known as edrophonium.

Patients taking sugammadex to reverse deep paralysis caused by rocuronium emerged, on average, in 2.2 minutes, according to pooled data from late-stage clinical trials conducted by Merck and submitted to the FDA. Patients taking neostigmine emerged in 19 minutes, while those taking a placebo emerged in 92.9 minutes.

In patients given sugammadex to reverse the effects of vecuronium, patients emerged in 3.8 minutes on average compared with 67.6 minutes for those taking neostigmine, the company said.

David Michelson, Merck's head of neuroscientific research, said that in a trial of 448 patients who received 16 milligrams of sugammadex per kilogram of body weight - an amount given only on an emergency basis - one patient experienced a clear anaphylactic reaction, characterized by a drop in blood pressure, hives, increased heart rate and difficulty breathing.

Two other patients had reactions that were not clearly anaphylactic but shared some symptoms, while seven or eight more had milder allergic reactions such as nausea and rash, he said.

In patients taking the normal dose used in routine surgeries - 4 milligrams per 1 kilogram of body weight - there were no clearly anaphylactic reactions and only one mild reaction, Michelson said, adding that in a trial of nearly 1,200 patients undergoing hip or knee surgery, those who were given sugammadex were no more likely than those who were not given it to have episodes of bleeding.

In 2012, nearly 5 million surgeries in the U.S. included the use of rocuronium and vecuronium. About 60 percent of those also involved the use of a reversal agent, according to IMS Health.

Merck's shares fell 0.9 percent to $48.09 in afternoon trading on the New York Stock Exchange.


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