Idenix plunges as FDA puts clinical hold on hepatitis C drug candidate

US biotech firm Idenix Pharmaceuticals (Nasdaq: IDIX) saw its shares tank 29% to $5.91 in morning trading after the company revealed that it had received a verbal communication form the Food and Drug Administration that a partial clinical hold has been placed on IDX184, the company's nucleotide polymerase inhibitor under development for the treatment of hepatitis C virus (HCV).

As a result of the recent occurrence of a serious cardiac-related adverse event encountered with a competitor's nucleotide polymerase inhibitor for the treatment of HCV - Bristol-Myers Squibb’s rival compound BMS-986094 leading to the suspension of a trial with the compound (The Pharma Letter August 2), the FDA has expressed an interest in further reviewing the safety of IDX184. The FDA previously delayed the development of the compound, and just this February lifted a partial clinical hold issued in 2010 after three cases of elevated liver function tests were observed in the Phase IIb study.

No evidence of cardiotoxicity to date, says company