This likely does not come as a surprise, given that FDA staff reviewers raised concerns about allergic reactions last spring (back story) and the agency subsequently issued a ‘not approvable’ letter this past summer (back story). Additional trials were expected and this has now been confirmed.

In a posting on its web site late yesterday, Schering-Plough wrote that “in order to address issues which primarily related to hypersensitivity/allergic reactions, the company plans to conduct an allergy sensitivity trial in healthy volunteers that will include repeat exposure to sugammadex. The study protocol is being developed, and the company anticipates conducting the trial in 2009.”

There was no info, though, on exactly when the trial should be completed and, if successful, when FDA approval for the drug, known as Bridion or sugammadex, might occur. The FDA rejection undercut Schering-Plough’s decision to pay $14 billion for Organon, where the drug originated. Schering-Plough repeatedly pointed to Bridion as one of several key reasons for the deal and some Wall Street analysts had forecast annual sales for the drug of up to $1 billion.

You may recall that, last week, Schering-Plough touted the drug as one of five “stars” of its research pipeline at a meeting with investors. UPDATE: Now, Leerink Swann analyst Seamus Fernandez says Schering-Plough was now unlikely to seek FDA approval before 2010, according to Reuters.

Hat tip to Shearings Got Plowed