Speculation that the Food and Drug Administration will give a nod for the generic version of Vancocin caused shares in ViroPharma to dip by about 33 percent. The rumors of the FDA's changed perspective strengthened after Laura Alvey, a spokeswoman for the F.D.A said in an e-mail message that the agency had "recently revised the bioequivalence recommendations for oral vancomycin from a clinical trial with bioequivalence endpoints to an in vitro method involving dissolution testing."
Vancocin or vancomycin is used exclusively to treat hospital-acquired bacterial infections caused in the lower digestive tract by the bacterium Clostridium difficile. Basically, the FDA's changed stance means that a clinical trial for generic vancomycin might not be necessary if it dissolves at the same rate as Vancocin. ViroPharma has intimated that it has filed a petition to stay the action with the F.D.A and added that it would file many more petitions to support "vigorous opposition to any approach that does not require rigorous scientific methods to demonstrate a rate and extent of drug release to the site of action consistent with good medicine and science." But analysts at Infinium Capital feel that a generic version of Vancocin could be available by early 2008. "Previously, generic manufacturers may not have been interested in developing this therapeutic due to its low revenue potential; however, with the recent sales growth of 133 percent in 2005, Vancocin is now on the radar screen," an analyst at Infinium Capital, Bernadine Leung, said.