Presidio Pharmaceuticals Successfully Completes Phase 1 Proof-of Concept for PPI-668, its Potent HCV NS5A Inhibitor, in Hepatitis C Patients with Genotype-1 Infection

San Francisco, CA – June 26, 2012 – Presidio Pharmaceuticals, Inc. announced today successful completion of Phase 1b clinical testing of its lead HCV NS5A inhibitor in patients with HCV genotype-1 infection, with positive efficacy and safety observations supporting advancement of PPI-668 to Phase 2 combination studies.

The randomized, blinded Phase 1b trial of PPI-668 involved sequential cohorts of treatment-naïve HCV genotype-1 patients who received oral doses of PPI-668 of 40, 80, 160 or 240 mg, once daily for three consecutive days. Within each 10-patient cohort, patients were randomized 8:2 to PPI-668 or placebo.

In all of the Phase 1b dose cohorts, PPI-668 was well tolerated with no serious or severe adverse events, no premature treatment discontinuations and no apparent pattern of treatment-related clinical side effects or laboratory abnormalities. PDF

Presidio Pharmaceuticals Announces a New Clinical Candidate, PPI-383, a Novel Pan-Genotypic Non-Nucleoside Polymerase Inhibitor for HCV

San Francisco, CA – April 21, 2012 – Presidio Pharmaceuticals, Inc. announced today that PPI-383, a novel non-nucleoside polymerase inhibitor to treat hepatitis C virus (HCV), has been nominated for clinical development and will be profiled by Richard Colonno, Ph.D., Chief Scientific Officer, in poster 1173 at the 47th Annual EASL meeting being held in Barcelona, Spain on April 21st, 2012.

PPI-383 is a potent, pan-genotypic inhibitor of HCV discovered at Presidio, which exhibits a favorable pharmacokinetic and safety profile in multiple animal species following oral dosing. PPI-383 binds to the Palm II pocket of the HCV polymerase (NS5B) and possesses biochemical and pharmaceutical properties critical to successful drug development, including a potential for once-daily oral dosing and minimal potential for drug-drug interactions. PPI-383 is currently undergoing further preclinical evaluation to support initiation of clinical studies alone and in combination with Presidio’s lead NS5A inhibitor, PPI-668, next year. PDF

Presidio Pharmaceuticals Announces Phase 1a-1b Clinical Results with PPI-668, a Potent Pan-genotypic HCV NS5A Inhibitor

San Francisco, CA – April 19, 2012 – Presidio Pharmaceuticals, Inc. announced results today from a Phase 1a-1b clinical trial of PPI-668, a potent, pan-genotypic HCV NS5A inhibitor being developed for the treatment of patients with chronic hepatitis C.

PPI-668 is Presidio’s second NS5A inhibitor to progress to clinical testing after Phase 1 clinical evaluation of PPI-461 (results previously reported at the annual meetings of the American Association for the Study of Liver Diseases (AASLD) in 2010 and 2011). Compared to PPI-461, PPI-668 exhibits more potent activity in vitro against HCV genotypes 3a and 6a and has a superior resistance profile. PDF

Presidio Pharmaceuticals Reports Progress with Hepatitis C Antiviral Programs

San Francisco, CA – January 09, 2012 – Presidio Pharmaceuticals, Inc. announced today the successful completion of a Phase 1a dose-ranging assessment of PPI-668, a potent, pan-genotypic second-generation hepatitis C virus (HCV) NS5A inhibitor, in healthy volunteers and subsequent advancement to a Phase 1b assessment of the dose-related efficacy in hepatitis C patients. PDF