Business Overview

9 Months Ended

Sep. 30, 2012

Business Overview [Abstract]

BUSINESS OVERVIEW

1. BUSINESS OVERVIEW

Overview

Idenix Pharmaceuticals, Inc., which we refer to together with our wholly owned subsidiaries as Idenix, we, us or our, is a biopharmaceutical company engaged in the discovery and development of drugs for the treatment of human viral diseases with operations in the United States and France. Currently, our primary research and development focus is on the treatment of patients with hepatitis C virus, or HCV, using nucleoside/nucleotide polymerase inhibitors and NS5A inhibitors. We have two HCV clinical candidates, IDX184, a nucleotide polymerase inhibitor, and IDX719, an NS5A inhibitor. In July 2012, we also submitted an investigational new drug application, or IND, to the U.S. Food and Drug Administration, or FDA, for our HCV nucleotide inhibitor, IDX19368. In August 2012, the FDA placed IDX184 on partial clinical hold and IDX19368 on clinical hold due to serious cardiac-related adverse events observed with a competitor’s nucleotide polymerase inhibitor, BMS-986094 (formerly INX-189). We are reviewing additional pre-clinical and clinical data and conducting further testing to respond to the FDA’s concerns.

In May 2003, we entered into a collaboration with Novartis Pharma AG, or Novartis, relating to the worldwide development and commercialization of our drug candidates, which we refer to as the development and commercialization agreement. In May 2003, we also entered into a stockholders’ agreement with Novartis, which we refer to as the stockholders’ agreement. On July 31, 2012, we and Novartis materially modified our collaboration by executing a termination and revised relationship agreement, which we refer to as the termination agreement, and by amending the stockholders’ agreement, which we refer to as the second amended and restated stockholders’ agreement. These agreements are described more fully in Note 4.

Our drug development programs and the potential commercialization of our drug candidates will require substantial cash to fund costs that we incur in connection with preclinical studies and clinical trials, regulatory review, manufacturing and sales and marketing efforts. We have incurred losses in each year since our inception and at September 30, 2012, we had an accumulated deficit of $685.4 million. We expect to incur losses over the next several years as we continue to expand our drug discovery and development efforts. As a result of continuing losses, we may seek additional funding through a combination of public or private financing, collaborative relationships or other arrangements and we may seek a partner who will assist in the future development and commercialization of our drug candidates. In July 2012, we filed a universal, automatically effective, well-known seasoned issuer shelf registration statement with the Securities and Exchange Commission, or SEC, for the issuance, in one or more public offerings, of common stock, debt securities and other securities at prices and on terms to be determined at the time of the applicable offering. In August 2012, we issued approximately 25.3 million shares of our common stock under this shelf registration statement and received $190.5 million in net proceeds. Additional funding may not be available to us or, if available, may not be on terms favorable to us. Further, any additional equity financing may be dilutive to stockholders, other than Novartis, which has the right to maintain its current ownership level. Novartis did not participate in the August 2012 offering and its ownership of our common stock was diluted from approximately 31% prior to the offering to approximately 25% as of October 24, 2012.

We believe that our current cash and cash equivalents will be sufficient to sustain operations through at least March 31, 2014. If we are unable to obtain adequate financing on a timely basis, we could be required to delay, reduce or eliminate one or more of our drug development programs, enter into new collaborative, strategic alliances or licensing arrangements that may not be favorable to us and reduce the number of our employees. We are subject to risks common to companies in the biopharmaceutical industry including, but not limited to, the successful development of products, clinical trial uncertainty, regulatory approval, fluctuations in operating results and financial risks, potential need for additional funding, protection of proprietary technology and patent risks, compliance with government regulations, dependence on key personnel and collaboration partners, competition, technological and medical risks and management of growth.

Basis of Presentation

The condensed consolidated financial statements reflect the operations of Idenix Pharmaceuticals, Inc. and our wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation.

The accompanying condensed consolidated financial statements are unaudited and have been prepared by us in accordance with generally accepted accounting principles in the United States of America, or GAAP, for interim reporting. Accordingly, these interim financial statements do not include all the information and footnotes required by GAAP for complete financial statements and should be read in conjunction with the audited consolidated financial statements for the year ended December 31, 2011, which are included in our Annual Report on Form 10-K filed with the SEC on March 6, 2012. These interim financial statements are unaudited, but in the opinion of management, reflect all adjustments (including normal recurring accruals) necessary for a fair statement of the financial position and results of operations for the interim periods presented. The year ended condensed consolidated balance sheet data presented for comparative purposes was derived from audited financial statements, but does not include all disclosures required by GAAP.

The preparation of condensed consolidated financial statements in accordance with GAAP requires management to make estimates and judgments that may affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosures of contingent assets and liabilities. On an on-going basis, we evaluate our estimates, judgments and methodologies, including those related to revenue recognition, our collaborative relationships, clinical trial expenses, impairment and amortization of long-lived assets including intangible assets, share-based compensation, income taxes including the valuation allowance for deferred tax assets, contingencies and litigation. We base our estimates on historical experience and on various other assumptions that are believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities. Actual results may differ from these estimates under different assumptions or conditions.

The results of operations for the interim periods are not necessarily indicative of the results of operations to be expected for any future period or the fiscal year ending December 31, 2012.

Recent Accounting Pronouncements

In December 2011, the Financial Accounting Standards Board, or FASB, issued Accounting Standard Update No. 2011-11, Disclosures about Offsetting Assets and Liabilities. The amendments in this update require an entity to disclose information about offsetting and related arrangements to enable users of its financial statements to understand the effect of those arrangements on its financial position. An entity is required to apply the amendments for annual reporting periods beginning on or after January 1, 2013, and interim periods within those annual periods. An entity should provide the disclosures required by those amendments retrospectively for all comparative periods presented. We do not expect its adoption to have a material impact on our financial position or results of our operations.