Novartis Halts Zelnorm Sales

Novartis says it is complying with an FDA request that it suspend U.S. sales of Zelnorm, its irritable bowel syndrome treatment. FDA made the request after a retrospective analysis of clinical trial data indicated a possible link between Zelnorm and incidents of heart attacks and stroke.

FDA approved the drug in 2002. According to the data review, 0.11% of patients taking Zelnorm experienced unusual cardiovascular events, compared with 0.01% of patients treated with a placebo.

"Although we have complied with FDA's request and are collaborating with the agency, we continue to believe that Zelnorm provides important benefits for appropriate patients," says Stephen Cunningham, head of U.S. clinical development and medical affairs at Novartis.

Denise Anderson, head of the health care practice at Zurich-based Landsbanki Kepler, says the impact of the removal may be significant. "The company had highlighted that the drug had blockbuster potential," she notes, adding that analysts had expected Zelnorm to hit $1 billion in sales by 2011. Novartis' sales of Zelnorm last year were $488 million in the U.S. and $73 million in the rest of the world.

Separately, FDA announced that three manufacturers of pergolide drug products, used to treat Parkinson's disease, will voluntarily remove them from the market because of the risk of damage to patients' heart valves. The products involved are Valeant Pharmaceuticals International's Permax and two generic versions of the drug.

FDA has cited adverse side effects in removing several drugs from the market in recent years. Examples include Pfizer's arthritis drug Bextra and Biogen Idec's multiple sclerosis drug Tysabri, both removed in 2005, and Merck's arthritis drug Vioxx, removed in 2004. Regulators cleared Tysabri to return last year with several restrictions.

According to Marvin D. Shepherd, director of the Center for Pharmacoeconomic Study at the University of Texas, Austin, the recalls reflect increased evaluation of postmarket drug safety by FDA. "The industry has to brace itself for more of this," he says. "It is going to haunt them for the next 10 years."