Genzyme diarrhea drug may be blockbuster

BOSTON (Reuters) - Genzyme Corp. GENZ.O said on Wednesday that an experimental drug it is developing to treat hospital-acquired diarrhea could generate annual sales of nearly $1 billion, if approved.

Speaking at the Reuters Biotechnology Summit in Boston, the company's chief executive, Henri Termeer, said he expects results from two late-stage trials of the drug, Tolevamer, for the treatment of Clostridium difficile-associated diarrhea, to be available in the first half of next year, with a potential approval in 2008.

If successful, the drug could add to an increasingly diverse stable of products from a company that five years ago was heavily reliant on the drug Cerezyme for Gaucher disease, a condition that causes enlargement of the liver and spleen.

Within the next two months, Cambridge, Massachusetts-based Genzyme expects to receive approval in Europe and the United States for Myozyme, its experimental treatment for Pompe disease, a potentially fatal muscular disorder.

Termeer said sales of Myozyme will not amount to much in 2006 but will be "material" in 2007. He said he sees the drug following a similar growth trajectory as its drug Fabrazyme for Fabry disease, a condition which causes fats to build up in blood vessels. The company expects sales of the drug to reach as much as $390 million this year.

Eventually Myozyme could become as big a product as Cerezyme, which will generate sales of nearly $1 billion this year and has been on the market for more than a decade, Termeer said.

Genzyme, which built itself into the fourth-biggest U.S. biotech by concentrating on developing high-priced drugs for diseases with tiny populations, is expanding. It is determined to build a cancer drug portfolio and is developing its cancer drug Campath to treat multiple sclerosis.

The company had halted mid-stage trials of Campath in multiple sclerosis after safety data turned up three cases of idiopathic thrombocytopenic purpura, or ITP, a severe autoimmune disorder. The company expects to be able to resume testing shortly, after submitting a safety monitoring plan to U.S. regulators.

"We are fully confident the FDA will find it acceptable," Termeer said, speaking of the plan. "By the summer we expect approval from the FDA to start a Phase III trial."

Genzyme's discussions with the FDA come as the agency prepares to decide whether to allow back on to the market a multiple sclerosis drug marketed by Biogen Idec Inc. (BIIB.O) and Elan Corp. Plc ELN.L (ELN.I).

Sales of the drug, Tysabri, were suspended early last year after three patients contracted a rare brain disease known as progressive multifocal leukoencephalopathy.

Earlier this month the FDA said Biogen could resume clinical trials in patients who had previously been receiving Tysabri. An advisory panel to the agency will meet in March to discuss the possible return of the drug.

Termeer said he believes Campath has several advantages over Tysabri, including convenience and the management of side effects.