Idenix Reports Advancement of HCV Development Pipeline

CAMBRIDGE, Mass., Jan. 9, 2012 /PRNewswire/ -- Idenix Pharmaceuticals, Inc. (NASDAQ: IDIX), a biopharmaceutical company engaged in the discovery and development of drugs for the treatment of human viral diseases, today announced the advancement of its hepatitis C virus (HCV) development pipeline.

IDX719: NS5A Program
Idenix announced today the initiation of a phase I clinical trial of the Company's NS5A inhibitor, IDX719. The first part of the study will evaluate safety, pharmacokinetics and food effect of IDX719 in 48 healthy volunteers. A subsequent part of the study will evaluate three days of IDX719 treatment in treatment-naïve genotype 1 HCV-infected patients and is expected to begin in the second quarter of 2012. Preclinical studies have shown that IDX719 has potent, pan-genotypic activity in vitro with the potential for once-daily dosing.

IDX19368 and IDX19370: Nucleotide Prodrug Program
Further, the Company has selected two additional nucleotide inhibitors, IDX19368 and IDX19370, as potential clinical candidates. The Company anticipates Investigational New Drug (IND) filings in mid-2012.

"Over the past year, Idenix has made significant progress in both our core nucleotide and NS5A programs," commented Ron Renaud, President and Chief Executive Officer of Idenix. "The preclinical profile of IDX719 is very competitive, and we are leveraging the Company's significant nucleotide chemistry expertise to discover novel nucleotides with promising properties as well as continuing to strengthen our IP position. We are excited about the potential of our novel antiviral compounds in the evolving HCV field in the coming year."

2011 Year-end Cash Balance
Idenix today reported that it ended 2011 with approximately $118.3 million of cash and cash equivalents. The Company's 2011 financial results have not yet been audited.

ABOUT IDENIX
Idenix Pharmaceuticals, Inc., headquartered in Cambridge, Massachusetts, is a biopharmaceutical company engaged in the discovery and development of drugs for the treatment of human viral diseases.  Idenix's current focus is on the treatment of patients with hepatitis C infection. For further information about Idenix, please refer to www.idenix.com.

CONFERENCE CALL AND WEBCAST INFORMATION
Idenix will hold a conference call today at 8:30 a.m. ET. To access the call, please dial (877) 640-9809 (U.S./Canada) or (914) 495-8528 (International) and enter passcode 40631574. A slide presentation will accompany the conference call and can be accessed on the Investor section of the Idenix website at www.idenix.com. Please log on approximately 10 minutes prior to the start of the call to ensure adequate time for any downloads that may be necessary.

A replay of the conference call and webcast will be available until January 23, 2012, by dialing (855) 859-2056 (U.S./Canada) or (404) 537-3406 (International) and enter the passcode 40631574.

FORWARD-LOOKING STATEMENTS

This press release contains "forward-looking statements" for purposes of the safe harbor provisions of The Private Securities Litigation Reform Act of 1995, including but not limited to the statements regarding the Company's future business and financial performance. For this purpose, any statements contained herein that are not statements of historical fact may be deemed forward-looking statements. Without limiting the foregoing, the words "expect," "plans," "anticipates," "intends," "will," and similar expressions are also intended to identify forward-looking statements, as are expressed or implied statements with respect to the Company's potential pipeline candidates, including any expressed or implied statements regarding the efficacy and safety of IDX184 or any other drug candidate; the successful development of novel combinations of direct-acting antivirals for the treatment of hepatitis C; the likelihood and success of any future clinical trials involving our drug candidates; and expectations with respect to funding of operations and future cash balances. Actual results may differ materially from those indicated by such forward-looking statements as a result of risks and uncertainties, including but not limited to the following: there can be no guarantees that the Company will advance any clinical product candidate or other component of its potential pipeline to the clinic, to the regulatory process or to commercialization; management's expectations could be affected by unexpected regulatory actions or delays; uncertainties relating to, or unsuccessful results of, clinical trials, including additional data relating to the ongoing clinical trials evaluating its product candidates; the Company's ability to obtain additional funding required to conduct its research, development and commercialization activities; the Company's dependence on its collaboration with Novartis Pharma AG; changes in the Company's business plan or objectives; the ability of the Company to attract and retain qualified personnel; competition in general; and the Company's ability to obtain, maintain and enforce patent and other intellectual property protection for its product candidates and its discoveries. Such forward-looking statements involve known and unknown risks, uncertainties and other factors that may cause actual results to be materially different from any future results, performance or achievements expressed or implied by such statements. These and other risks which may impact management's expectations are described in greater detail under the heading "Risk Factors" in the Company's quarterly report on Form 10-Q for the quarter ended September 30, 2011, as filed with the Securities and Exchange Commission (SEC) and in any subsequent periodic or current report that the Company files with the SEC.

All forward-looking statements reflect the Company's estimates only as of the date of this release  (unless another date is indicated) and should not be relied upon as reflecting the Company's views, expectations or beliefs at any date subsequent to the date of this release. While Idenix may elect to update these forward-looking statements at some point in the future, it specifically disclaims any obligation to do so, even if the Company's estimates change.

Idenix Pharmaceuticals Contacts:
Kelly Barry (617) 995-9033 (media)
Teri Dahlman (617) 995-9807 (investors)

SOURCE Idenix Pharmaceuticals, Inc.