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SCYNEXIS' SCY-635 Demonstrates Clinically Relevant Single-Agent Results in a Phase 1b Study in Adults with HCV

Results presented in an oral presentation at EASL; Phase 2 studies to be initiated in 2H09

RESEARCH TRIANGLE PARK, N.C.--(BUSINESS WIRE)--Apr 24, 2009 - Drug discovery company SCYNEXIS, Inc. today presented positive results from a Phase 1b single-agent, randomized, double-blind, placebo-controlled study of its lead, oral, antiviral drug candidate, SCY-635, in adult patients with genotype 1 chronic hepatitis C infection. SCY-635, a novel cyclophilin inhibitor, represents a new pharmacological class of inhibitors of hepatitis C virus (HCV) replication. Results were presented during an oral presentation at the European Association for the Study of the Liver (EASL) Annual Meeting in Copenhagen on April 24, 2009.

In this 15-day study, SCY-635 was well-tolerated with no serious adverse events, no discontinuations and no dose-limiting toxicities. At the highest dose tested in the study (900 milligrams/day) SCY-635 exhibited clinically relevant antiviral activity and substantial suppression of plasma viremia throughout the treatment period. In the 900 mg cohort all treated patients showed a viral load reduction with a group mean maximum decrease of 2.2 log10 on the last day of the study (p < 0.05 for the day 15 comparison).

“In this single-agent study SCY-635 demonstrated highly potent antiviral activity that was sustained throughout treatment with the nadir occurring on the last day of the study, suggesting that with a longer treatment period we may see even greater reductions in viral load,” said Dr. Sam Hopkins, SCYNEXIS' Chief Scientific Officer. “These clinical results combined with earlier preclinical work demonstrating additive or synergistic activity with both approved and investigational agents suggest that in a combination regimen, SCY-635 may improve rates of sustained virological response.”

“These results establish proof-of-concept for SCY-635 in HCV patients and more broadly support our proprietary discovery platform, which is focused on the development of cyclophilin inhibitors for multiple diseases,” said Dr. Yves Ribeill, President and Chief Executive Officer of SCYNEXIS. “Given that we have seen no dose related adverse events at our highest tested dose, we are in the process of optimizing the dose and regimen of SCY-635 in ongoing Phase 1 studies and plan to initiate a Phase 2 study in patients infected with HCV in the second half of the year.”

About the Clinical Trial

The clinical study was conducted as a Phase 1b, randomized, double-blind, placebo-controlled, multi-dose study in adult volunteers with genotype 1 chronic hepatitis C infection. SCY-635 was given as an oral capsule for 15 consecutive days. Patients were eligible for entry if they had plasma viremia in excess of 100,000 IU/ml, no evidence of decompensated liver function, no co-infections and if liver function tests were ‰¤ 2.5x Upper Limit of Normal. The study was conducted in two parts. Thirty-six subjects received SCY-635 once daily and twenty subjects received SCY-635 three times daily. All studies were conducted in the U.S.

About SCY-635 and SCYNEXIS' Cyclophilin Inhibitor Platform

SCY-635 represents a new class of therapeutic agents for the treatment of HCV infection. SCY-635 is the first candidate in a novel class of non-immunosuppressive cyclophilin inhibitors owned by SCYNEXIS. Cyclophilins are a family of enzymatic proteins that assist in the folding and transport of other proteins synthesized within a cell. Cyclophilin inhibitors, such as Cyclosporine A, have been used for decades for the prophylaxis of organ rejection in transplant patients. Scientists at SCYNEXIS have synthesized derivatives of Cyclosporine A in which cyclophilin binding activity (which mediates anti-HCV activity) is separated from calcineurin binding activity (which mediates immunosuppression). A growing body of scientific evidence indicates that non-immunosuppressive analogs of Cyclosporine A may have applications in multiple therapeutic areas. Cyclophilins play a central role in the pathophysiology of chronic viral infection, neurodegenerative diseases and malignant transformation. Cyclophilin inhibition therefore represents an attractive target for drug discovery and development.


SCYNEXIS is a premier drug discovery and development company delivering effective and innovative drug pipeline solutions to pharmaceutical and global health partners. The Company, which is located in Research Triangle Park, North Carolina, is also developing a proprietary internal pipeline based on cyclophilin inhibitors, a class of drugs that hold significant potential for the treatment of a broad range of diseases. Please visit our website at


Contact: Company Contact:
Terry Marquardt
Media Relations:
MacDougall Biomedical Communications
Sarah Cavanaugh, 781-235-3060


Posted: April 2009