By Nathalie Tadena
June 20, 2013, 5 p.m. ET
Idenix Pharmaceuticals Inc. (IDIX) said the U.S. Food and Drug Administration has requested additional preclinical safety data for one of the biopharmaceutical company's hepatitis C treatments, which will delay the start of clinical trials.
Shares, which had been halted ahead of the news, slumped 25% to $3.87 after hours when trading resumed. The stock has fallen 52% over the past 12 months, through the close.
The company said it must provide a satisfactory response to the FDA before clinical trials can begin in the U.S. for its IDX20963 lead uridine nucleotide prodrug candidate. Idenix said it recently submitted an investigational new drug application for IDX20963 to the FDA that included preclinical data demonstrating potent, pan-genotypic activity.
Hepatitis C is a blood-borne virus that afflicts an estimated four million Americans and 170 million people world-wide. The disease often is contracted during sex or by sharing needles. Current treatment of the drug requires long courses of painful injections and often doesn't work. Drug makers have been racing to find pills that are both more potent and easier to take.
In February, the company said it would discontinue its clinical development program for two of its investigational treatments for hepatitis C, after the FDA said the treatments would remain on clinical hold.
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