FDA halts testing of Idenix drug for hepatitis
Idenix Pharmaceuticals Inc., a Cambridge-based drug company, said yesterday that federal regulators suspended testing of its hepatitis C drug, resulting in a 38 percent drop in the company's stock.
Idenix said the US Food and Drug Administration reported that it did not think the drug, called valopicitabine, was effective enough to accept its gastrointestinal side effects, such as vomiting and nausea. The FDA declined to comment.
"I don't think it was that big a surprise," said Howard Liang , a biotechnology analyst for Boston-based Leerink Swann & Co. "I think many people have been saying that it is questionable that this drug should be further developed. I think the FDA made the decision for them."
Valopicitabine was an important drug for Idenix because of the large number of people suffering from hepatitis C, a liver condition that could cause organ failure, cancer, or cirrhosis. Raymond Chung , director of hepatology at Massachusetts General Hospital , said about 4 million people in the United States and 170 million worldwide suffer from hepatitis C .
During the testing phases, pills of valopicitabine were used with interferon and ribavirin, the two drugs currently used to treat hepatitis C. Eugene Trogan, a biotechnology analyst at Morgan Joseph & Company, a New York financial firm, said the side effects of the drug prompted researchers to decrease the dosage from 800 milligrams to 200 milligrams.
Teri Dahlman, spokeswoman for Idenix, said the company will discuss the future of the drug with
"We're considering all of our options," she said.
The FDA action prompted Idenix's stock to tumble.
Novartis AG, which moved its global research headquarters to Cambridge in 2002 , had bought the majority of Idenix's shares for $255 million in 2003 as part of its efforts to become a major player in treatment of infectious diseases such as hepatitis B, hepatitis C, and HIV. Novartis plans on moving its Vaccines and Diagnostics division to Cambridge by early August.
Idenix has begun selling a hepatitis B drug it calls Tyzeka after receiving FDA's approval for commercialization last year. The drug received approval for sales by the European Union this year and will be sold under the name Sebivo. But the market for hepatitis B treatment is smaller and more crowded, limiting profits.
Idenix has not given up on the hepatitis C drug market. Dahlman said the company might seek FDA approval for further testing of another drug.
Chung said there is great need for drugs that can be taken orally, unlike interferon, as well as drugs that come with less severe side effects. Current treatment requires a year of therapy with about a 54 percent chance of cure.
"A year of their life could be diminished by having to go through the therapy," he said. "The therapy involved has difficulty being tolerated by many patients."
Se Young Lee can be reached at vlee@globe.com. 
