Pipeline :: Hepatitis C

Data from a Phase 1b trial and from an in vitro study of SD-101’s mechanism of action show that SD-101 is 1) well tolerated and safe and 2) induces both IFN-lambda and IFN-alpha at concentrations producing antiviral activity. The data will be presented at the 45th Annual Meeting of the European Association for the Study of the Liver in Vienna, Austria in April 2010. We believe these studies differentiate SD-101 from standard-of-care as well as emerging treatments for chronic HCV infection. SD-101 hepatitis C therapy utilizes a novel second-generation Toll-like Receptor 9 (TLR9) agonist and may offer a more effective therapeutic option for patients chronically infected with the hepatitis C virus (HCV).

Data from the Phase 1b study of SD-101 in treatment-naïve, genotype 1 HCV patients show:

A safety and tolerability profile that compares favorably to that of IFN-alpha, at all four doses tested;
A dose-dependent antiviral response, with 100% of patients at the highest dose experiencing a greater than one (1) log reduction in viral load; and
The potency of SD-101 as confirmed by biomarker analysis in patients. The biomarker data point to substantial, dose-related increases in the expression of key antiviral genes (MX-B and ISG-54k) and genes indicating enhanced immunity (IP-10 and MCP-1).

The Phase 1b study evaluated four dose levels of SD-101 in 34 chronically infected, treatment-naïve, genotype 1 HCV patients. SD-101 was administered as a monotherapy once weekly, for four weeks, in doses from 0.1 to 5.0 milligrams per week.

The in vitro data from a study of the drug in human blood cells demonstrate that compared to first-generation TLR9 agonists, SD-101 stimulates 20-fold higher levels of both IFN-alpha and IFN-lambda, two classes of IFNs with potent activity against HCV.

Commercial Opportunity

With the completed acquisition of Symphony Dynamo in January 2010, Dynavax has full development and commercialization rights to SD-101. As such, SD-101 is now part of the portfolio of development programs that are available for partnership.

According to the World Health Organization, there are 170 million people worldwide chronically infected with HCV. We estimate the current worldwide market for HCV therapeutics is over $3 billion annually. While there is no vaccine available to prevent HCV, current therapy includes pegylated interferon alpha and the antiviral drug ribavirin. Both of these therapies may cause significant side effects and are only effective in treating half of all patients infected with HCV.

Our HCV therapy is designed to be used in combination with oral antivirals -- including standard-of care and emerging therapies -- to stop HCV viral replication and induce a long-lasting T-cell immune response.