Schering Drug Derailed by Power of One

OKLAHOMA CITY -- Did a single patient's allergic reaction, one that was overcome without any major complications, ultimately cripple plans for Schering-Plough's (SGP Quote) breakthrough anesthesia drug?

During early clinical trials of Sugammadex, a novel agent given to reverse anesthesia blocks within minutes, "subject 008" suffered some troubling complications. As doctors administered the drug, the patient began exhibiting a number of symptoms -- including rash, nausea and flushing -- that could signal a serious "anaphylactic" reaction.

Once doctors halted infusion of the drug, however, the patient recovered without any further treatment at all.

Nevertheless, Schering-Plough took an extra precaution that may have hurt Sugammadex's chances for U.S. approval: Despite just one patient out of about 2,000 suffering a possible reaction, the company conducted another study focused specifically on hypersensitivity to the drug.

Schering-Plough itself spotted no further problems during its expanded review. However, since the company supplied its new results to FDA experts at the last minute, the agency decided to take a closer look on its own. After scouring the databases from late-stage trials, which are designed to measure efficacy rather than risks, the FDA came up with four more cases of potential hypersensitivity to the drug.

In every one of those cases, however, the patients appeared to suffer primarily from stomach problems -- such as nausea and vomiting -- that often follow surgery regardless of the anesthesia drug involved. Moreover, in at least two of those cases, the nausea surfaced a full day after the operations had taken place and continued long after the reversal agent would have seemingly worn off.