Idenix's Candidate on Clinical Hold

Idenix Pharmaceuticals, Inc. ( IDIX - Snapshot Report ) recently received a verbal notice from the US Food and Drug Administration (FDA) informing the company about a clinical hold on its hepatitis C candidate, IDX19368.

Idenix had submitted an investigational new drug (IND) application for IDX19368 in July this year. The company was looking to commence studies in the third quarter. However, considering the clinical hold, the initiation of studies with IDX19368 could be delayed. IDX19368 was not exposed to any patients to date.

We remind investors that earlier this month Idenix had received another verbal notice from the FDA, which placed the company’s other hepatitis C candidate -- IDX184 -- on partial hold.

The FDA had asked Idenix to conduct additional cardiac tests on patients in the ongoing phase IIb study of IDX184 in combination with pegylated-interferon and ribavirin for the treatment of HCV. Idenix has already scheduled 50 patients for echocardiograms and expects to submit data to the US regulatory authority in the coming weeks.

We note that, in June 2012, Idenix had reported positive interim data from the phase IIb clinical study. The data demonstrated that patients on IDX184 combination therapy achieved 100% and 80% sustained virologic response (SVR) with 100 mg and 50 mg doses, respectively.

In July 2012, the safety data of the trial was reviewed by an independent data safety monitoring board and found to be consistent with that of pegylated-interferon and ribavirin alone. Idenix had plans of initiating another study on IDX184 by the end of 2012, which might get delayed due to the FDA’s action. Presently no patients are receiving IDX184 around the globe.

The FDA placed IDX19368 on clinical hold to review its safety concerns after serious cardiac-related adverse events were found to be associated with Bristol-Myers Squibb Company’s ( BMY - Analyst Report ) BMS-986094 (formerly known as INX-189). BMS-986094 is also a nucleotide polymerase inhibitor being developed for the treatment of HCV. Bristol-Myers recently decided to discontinue with BMS-986094 due to its safety issues.

Bristol-Myers has agreed to help Idenix with relevant information on BMS-986094 to resolve this issue. We remind investors that BMS-986094 was added to Bristol-Myers’ pipeline following its acquisition of Inhibitex Inc. earlier this year.

The management mentioned that both IDX19368 and IDX184 fall in the same broader class and have same metabolite as the Bristol-Myers candidate. But many attributes of Idenix’s compounds differ from that of BMS-986094.

Our Recommendation

We currently have a Neutral recommendation on Idenix. The stock carries a Zacks #3 Rank (Hold rating) in the short run.