ImQuest Identifies First Non-nucleoside Inhibitors of Hepatitis B Virus

HBV is unusual in that it uses reverse transcriptase to replicate, a characteristic usually seen only in retroviruses such as HIV. Several nucleotide/nucleoside analog inhibitors are approved for the treatment of chronic hepatitis B virus (HBV) infection -- lamivudine (Epivir-HBV), adefovir (Hepsera), entecavir (Baraclude), telbivudine (Tyzeka), and tenofovir (Viread) -- and some are dually active against both HBV and HIV.

Although well known as a component of antiretroviral therapy for HIV, there are currently no approved non-nucleoside reverse transcriptase inhibitors for HBV.

But at the recent 13th International Symposium on Viral Hepatitis and Liver Disease (ISVHLD), investigators described the discovery of a set of pyrimidinedione non-nucleoside inhibitor agents that exhibited anti-HBV activity in the laboratory.

Below is the text of a press release from ImQuest Life Sciences describing the findings.

ImQuest Presents Data on the Anti-Hepatitis B Virus Activity of Pyrimidinediones at the 13th ISVHLD Meeting in Washington D.C.

Frederick, MD -- March 31, 2009 -- ImQuest Life Sciences today presented important new results on the continued development of the pyrimidinedione small molecules as antiviral agents at the 13th International Symposium on Viral Hepatitis and Liver Disease meeting held last week in Washington D.C. ImQuest's screening efforts have identified ten pyrimidinediones as inhibitors of HBV replication, with two compounds yielding potent inhibition of HBV replication at sub-micromolar concentration levels. The two lead molecules, IQP-0568 and IQP-0589 have also been shown to be active non-nucleoside inhibitors of HIV replication, but inactive against a panel of other RNA and DNA viruses, suggesting specificity for antiviral activity against viruses that encode a reverse transcriptase. These studies provide a fundamental structural basis for the development of first in class non-nucleoside inhibitors of HBV replication. The data were presented by Todd B. Parsley, PhD, Director of Hepatitis Virus Research as a component of a session entitled, "Experimental Approaches to Therapy of HBV." The studies included ImQuest co-authors Lu Yang, MD and Robert W. Buckheit, Jr., PhD.

"These results reveal the potential for the development of the pyrimidinediones as a first in class non-nucleoside inhibitor of HBV infection," said Dr. Buckheit, Executive Vice President and Chief Scientific Officer of ImQuest Life Sciences. "These studies are also intriguing from the perspective of potential treatment options for patients co-infected with HBV and HIV."

The research presented continues the scientific partnership between ImQuest Life Sciences and Samjin Pharmaceuticals as a component of their joint efforts to develop new and novel anti-infective and anti-cancer therapeutics.

ImQuest Life Sciences, a privately held U.S. company located in Frederick, Maryland specializes in early stage drug development of novel compounds for the treatment of infectious disease and cancer. ImQuest BioSciences, also located in Frederick, Maryland, is a leading provider of anti-infective therapeutic and microbicide development services to the biotechnology and pharmaceutical industry.

4/7/09

Source
Imquest Life Sciences. ImQuest Presents Data on the Anti-Hepatitis B Virus Activity of Pyrimidinediones at the 13th ISVHLD Meeting in Washington D.C. Press release. April 1, 2009.