Idenix Puts IDX184 On Hold, FDA to Conduct Further Review

LITTLE ROCK, AR– Idenix Pharmaceuticals, a global biopharmaceutical company that works for the discovery and improvement of medications for human viral diseases treatment, announced that the U.S. Food and Drug Administration (FDA) has placed a partial clinical hold on IDX184, the nucleotide polymerase inhibitor that is being developed by Idenix for the treatment of hepatitis C virus (HCV).

According to the FDA, it has to further review the safety of IDX184, which is why it has been put on hold.

This was because of a recent severe cardiac-related effect observed on the nucleotide polymerase inhibitor for HCV treatment developed by a competitor. The FDA has asked the Company for more data regarding patients who have received IDX184 treatment.

In the ongoing clinical trial of IDX184, combined with ribavirin and pegylated interferon, no evidence of cardiotoxicity has been found yet in patients who were given IDX184 with ribavirin other than what is observed with ribavirin alone.

Also called tribavirin, ribavirin is an anti-viral drug used for hepatitis C, RSV infection, and viral hemorrhagic fever treatment. To date, no patient has received IDX184 alone worldwide.

Idenix assures the safety of every patient and is committed to complying with the FDA’s requests. Continuous discussions with the FDA representatives will be pushed after submitting the data requested by the FDA.

About Idenix

Headquartered in Little Rock, Arkansas, Idenix Pharmaceuticals is a global biopharmaceutical company for the discovery and development of medications for human viral diseases treatment.

For nearly 20 years, the company has invested in research and development as well as innovative technologies to come up with pharmaceutical solutions that work. Currently, the company focuses on the treatment of hepatitis C infection patients. For more information about Idenix, please visit www.idenix.com.

About IDX184

IDX184 is a new nucleotide prodrug of 2′-methyl guanosine that targets the liver to treat patients with hepatitis C virus.

It includes Idenix’s proprietary liver-targeting technology that provides the supply of nucleoside monophosphate to the liver, which forms nucleoside triphosphate in high levels. This can maximize drug efficacy and restrict systemic side effects as low as the dosage is low and given once daily.

In the ongoing clinical trial of IDX184 combined with ribavirin, 100% of 31 patients in the 100mg arm who completed a month’s worth of ribavirin treatment and achieved a prolonged virologic response were able to show a sustained virologic response a month after the treatment.

A third-party data corroborates with Idenix’s findings. A safety monitoring board evaluated the safety figures for this study. The board confirmed that the side effects associated with the combination of IDX184 and ribavirin are the same as that of ribavirin alone.

About the partial clinical hold

A partial clinical hold refers to the temporary delay of only a portion of the clinical work under the new drug application. Under this FDA directive, a specific protocol is not allowed to proceed.

But other protocols can be performed. This means that Idenix is not allowed by the FDA to enroll patients into supplementary clinical trials until the FDA agrees on the next clinical trial design.