We use our proprietary HepDirect prodrug technology to target drugs to the liver, resulting in increased levels of the pharmacologically active form of the drug in the liver and decreased levels in non-liver tissues. This targeting is accomplished by chemically modifying a drug to render it inactive until the modification added is cleaved off by a liver-specific enzyme. The modified, inactive form is known as a HepDirect prodrug. We believe this approach may significantly improve efficacy and/or safety of certain drugs.

Our HepDirect technology may be useful for improving certain currently marketed drugs or applied to certain product candidates. In either case, the goal is to produce a new, proprietary drug candidate with improved properties for treating difficult diseases. These candidates may then be developed and marketed by us and/or by companies with which we collaborate. In some cases, we may work with other companies to apply our technology and expertise to compounds in their pipeline that would benefit from this approach.

Pradefovir, MB07133 and MB07811 use our HepDirect technology, as do several of our research programs. In addition to our internal programs, we have worked with Merck and Idenix to discover treatments for hepatitis C by seeking to liver-target compounds they have designated. We may similarly leverage this technology with other companies.