Presidio Pharmaceuticals, Inc. is a San Francisco-based clinical-stage pharmaceutical company dedicated to the discovery and development of small-molecule antiviral therapeutics. Presidio’s current focus is on developing therapies for hepatitis C virus (HCV) infection. With a pipeline consisting of compounds targeting both the NS5A and NS5B proteins of HCV, Presidio is well positioned to compete in the growing HCV therapy market (see Programs & Pipeline for more details). Presidio’s goal is to discover and advance small-molecule, antiviral drug candidates that are potent, have pan-genotypic antiviral activity, offer convenient once-daily oral dosing and can be combined with other classes of HCV antivirals to combat viral resistance. The best future combination regimens will require such characteristics to simplify patient treatment and to ensure that drug therapy will be effective against the wide variety of known HCV genotypes.