FDA holds experimental HCV drug

FDA has placed a partial clinical hold on Idenix Pharmaceuticals’ nucleotide polymerase inhibitor under development for the treatment of hepatitis C virus (HCV), citing cardiac-related adverse events that occurred in trials late last month for Bristol-Myers Squibb’s nucleotide polymerase inhibitor also under development for HCV treatment. Both were undergoing testing in mid-stage trials.

FDA has requested additional data on patients treated with IDX184. Idenix said it will immediately begin work to comply with FDA’s request and expects to submit these data to FDA in the coming weeks. The company intends to have an ongoing discussion with FDA following the submission of this data.

In previous clinical trials as well as the ongoing phase 2b clinical trial of IDX184 in combination with pegylated interferon and ribavirin (PegIFN/RBV), Idenix said that there has been no evidence to date of cardiotoxicity in patients taking IDX184 with PegIFN/RBV beyond that seen with PegIFN/RBV alone. There are currently no patients receiving IDX184 worldwide.

"While the hold on testing by the FDA is a significant setback in the development process for this novel oral monotherapy option for hepatitis C, it should be noted that the drug itself has not been directly tied to cardiovascular issues and safety assessments to date have not raised red flags," said Formulary Clinical Editor David Calabrese, RPh, MHP, VP, Clinical Pharmacy Services & Chief Pharmacy Officer, Catamaran.

"FDA’s impending review of additional safety evidence to date with IDX184 can be considered routine today, given the heart-related adverse effects seen with the product’s competitor, of similar chemical origin," added Calabrese, who is also clinical assistant professor, Northeastern University Bouvé College of Health Sciences, School of Pharmacy, Boston.