Corporate Overview

We are a clinical-stage pharmaceutical company committed to discovering, developing and commercializing novel drugs to treat viral infections. Our primary focus is on the development of oral therapeutics for the treatment of hepatitis C virus (“HCV”). We currently have two product candidates and a series of preclinical candidates nearing preparation for clinical development:

• RG7128, a pro-drug of PSI-6130 for the treatment of HCV, is entering a phase 2b clinical trial through a collaboration with Roche;
• PSI-7977, a chirally pure isomer of PSI-7851 is a second generation nucleotide analog for the treatment of HCV, and is currently in a phase 2a trial;
• Purine nucleotide series.

Additionally, we are continuing to identify the best path forward for the development of Racivir, for the treatment of HIV following the completion of a Phase 2 clinical trial.

Our research and development efforts focus on a class of compounds known as nucleoside analogs, which act to inhibit the enzymes required for viral replication. We are applying our expertise in nucleoside chemistry to the discovery and development of additional antiviral therapeutics for HCV.

Our Strategy

Our primary objective is to become a leader in discovering, developing and commercializing novel antiviral therapeutics that provide a competitive advantage and address unmet medical needs. Our primary focus is on the development of oral therapeutics for the treatment of HCV. To achieve this goal, we are pursuing the following strategies:

• Focus on developing our current clinical-stage product candidates and advancing them toward marketing approval.
• Maintain a broad pipeline of potential product candidates to diversify commercial opportunities and reduce our dependence on any one product candidate’s clinical or commercial success.
• Leverage our core competency in nucleoside chemistry for research innovation and the discovery of additional product candidates.
• Commercialize our products ourselves or through collaborations, where appropriate, to optimize economic returns while managing financial risk.