Idenix second-quarter total revenues decrease to $1.3 million

Idenix Pharmaceuticals, Inc. (Nasdaq: IDIX), a biopharmaceutical company engaged in the discovery and development of drugs for the treatment of human viral diseases, today reported unaudited financial results for the second quarter and six months ended June 30, 2010. At June 30, 2010, Idenix's cash and cash equivalents totaled $51.0 million.

Research and Development Highlights

Phase IIa: IDX184, a liver-targeted hepatitis C virus (HCV) nucleotide prodrug

• All patients have recently completed dosing in the 14-day Phase IIa clinical trial evaluating 50 to 200 mg doses of IDX184 in combination with pegylated interferon and ribavirin in treatment-naive HCV genotype 1-infected patients. Data from this study have been submitted to the annual meeting of the American Association for the Study of Liver Diseases (AASLD), which will be held at the end of October in Boston.

Phase I/II: IDX320, an HCV protease inhibitor

• In the second quarter of 2010, Idenix initiated a three-day proof-of-concept study in 38 treatment-naive HCV genotype 1-infected patients. This trial is a Phase I/II randomized, parallel-arm, double-blind, placebo-controlled study evaluating the safety and antiviral activity of IDX320. The study is evaluating four doses of IDX320, ranging from 50 to 400 mg once-per-day, and one 200 mg twice-daily dose.  Data from this study will be submitted as a late-breaker to the upcoming AASLD meeting.

Phase I: IDX184/IDX320 Combination

• In July 2010, Idenix conducted a two-week Phase I, randomized, double-blind, placebo-controlled study to evaluate the pharmacokinetic drug-drug interaction between IDX320 and IDX184 in healthy volunteers. Two cohorts were evaluated in the study with 10 subjects in each cohort randomized eight to active drug and two to placebo. Subjects in the first cohort received 400 mg once-daily of IDX320 plus placebo for the first week, subsequently adding 100 mg once-daily of IDX184 for the second week. Subjects in the second cohort received 100 mg once-daily of IDX184 plus placebo for the first week, subsequently adding 400 mg once-daily of IDX320 for the second week. Data analysis is ongoing.

Phase I: IDX375, an HCV non-nucleoside polymerase inhibitor

• In the second quarter of 2010, Idenix continued the Phase I clinical trial in healthy volunteers evaluating single and multiple doses, ranging from 200 to 1200 mg per day, of the free acid form of IDX375.  Assuming favorable data in this study, the company expects that a three-day proof-of-concept study in treatment-naive genotype 1-infected patients will be initiated in the second half of 2010. An abstract from this program has been submitted to the upcoming AASLD meeting.

"I am pleased to report that our three hepatitis C clinical programs continue to advance and we are also on track to select a clinical candidate with pan-genotypic properties from our preclinical NS5A program later this year," said Jean-Pierre Sommadossi, Ph.D., chairman and chief executive officer of Idenix. "Assuming favorable clinical results, we will submit data to regulatory agencies from the IDX184 Phase IIa study, the IDX320 proof-of-concept study and the IDX184/IDX320 drug-drug interaction study to support discussions related to the potential initiation of a combination study of IDX184 and IDX320 in HCV-infected patients in the second half of the year."

Second Quarter 2010 Financial Results

For the second quarter ended June 30, 2010, Idenix reported total revenues of $1.3 million, compared to total revenues of $2.4 million in the second quarter of 2009. The company reported a net loss of $16.3 million, or a loss of $0.23 per basic and diluted share, for the second quarter ended June 30, 2010, compared to a net loss of $16.3 million, or a loss of $0.28 per basic and diluted share for the second quarter ended June 30, 2009.

For the six months ended June 30, 2010, Idenix reported total revenues of $4.0 million, compared to total revenues of $6.5 million for the six months ended June 30, 2009. The company reported a net loss of $32.5 million, or a loss of $0.47 per basic and diluted share, for the six months ended June 30, 2010, compared to a net loss of $29.2 million, or a loss of $0.50 per basic and diluted share, for the six months ended June 30, 2009.

2010 Financial Guidance

The company expects that its current cash and cash equivalents, together with the anticipated royalty payments associated with product sales of Tyzeka®/Sebivo® (telbivudine), can fund operations into mid-2011. This guidance assumes no additional milestone payments, license fees, reimbursement for development programs and no financing activities.