Isis Announces Antisense Targeting Of HBV Produces Dose-Dependent Reductions In Hepatitis B Virus In An Animal Model Of HBV

CARLSBAD, Calif., March 24, 2014 /PRNewswire/ -- Isis Pharmaceuticals, Inc. ISIS -4.37% announced that treatment with an antisense compound targeting hepatitis B virus (HBV) produced dose-dependent reductions in all measured liver and serum viral markers of HBV infection in animal models of HBV infection.  These data will be presented at the 49th annual meeting of the European Association for the Study of the Liver (EASL) by Dr. Gaetan Billioud, from the Scripps Research Institute in London, England.  Isis is currently evaluating antisense targeting of HBV with ISIS-HBVRx in a Phase 1 study in healthy volunteers. 

"Hepatitis B virus infection is a serious health problem that can lead to significant and potentially fatal health conditions, including cirrhosis, liver failure and liver cancer. Chronic HBV infection is one of the most common persistent viral infections in the world. Currently available therapies, although effective in reducing circulating HBV in the blood, do not efficiently inhibit HBV antigen production and secretion, which are associated with poor prognosis and increased risk of liver cancer," said Dr. Stefan Wieland, assistant professor of experimental virology at The Scripps Research Institute.  

"These data are encouraging as they demonstrate that antisense drugs are able to efficiently reduce HBV-associated antigens as well as circulating HBV in an animal model of disease.  As such, these results provide support for the development of ISIS-HBVRx for the treatment of patients with chronic HBV infection."

These preclinical data, which will be presented by Dr. Gaetan Billioud from The Scripps Research Institute during a presentation on April 12 at EASL, demonstrate that antisense targeting of HBV RNA could be an effective approach to treating patients with chronic HBV infection.  In this study, an antisense compound targeting HBV produced dose-dependent reductions of HBV-associated antigens, including  HBsAg  (hepatitis B surface antigen), which is present in both acute and chronic infections and is associated with a poor prognosis in patients with chronic HBV infection.  In addition, other measures of viral infection were reduced in both the liver and serum in this mouse model of disease.   

"While chronic hepatitis B virus is currently treated with oral antiviral agents or injectable interferons, these treatments do not clear HBV and do not effectively clear HBV antigens from these patients.  As a result, patients are unable to fully control HBV infection and achieve sustained disease remission.  Many of these patients are at elevated risk for severe liver complications such as cirrhosis and primary liver cancer.  By targeting and suppressing viral mRNAs in the liver, treatment with ISIS-HBVRx added to current therapies could result in greater viral inhibition and permit greater immune system activity against the virus," said Richard Geary, Ph.D., senior vice president, development at Isis.   "Based on all of the preclinical data, including the animal data that will be presented at EASL, we initiated a Phase 1 study of ISIS-HBVRx late last year, which we plan to complete this year."

The Phase 1 study of ISIS-HBVRx is a randomized, placebo-controlled, dose-escalation study in approximately 30 healthy volunteers.  This study is designed to evaluate the safety, tolerability, and pharmacokinetics of single and multiple doses of ISIS-HBVRx.  ISIS-HBVRx, formerly referred to as ISIS-GSK3Rx, is an investigational drug that is designed to target viral mRNA and reduce the production of viral proteins associated with HBV infection and replication.  ISIS-HBVRx is part of Isis' alliance with GSK.  Isis will develop ISIS-HBVRx to completion of Phase 2 proof-of-concept, after which GSK has an exclusive option to in-license and further develop and commercialize ISIS-HBVRx. Isis has already earned $10 million in milestone payments from GSK for ISIS-HBVRx and is eligible to earn additional pre-licensing milestone payments from GSK as ISIS-HBVRx advances in development.  Isis is also eligible to receive double-digit royalties on sales of ISIS-HBVRx. 

ABOUT ISIS PHARMACEUTICALS, INC.

Isis is exploiting its leadership position in antisense technology to discover and develop novel drugs for its product pipeline and for its partners.  Isis' broad pipeline consists of 31 drugs to treat a wide variety of diseases with an emphasis on cardiovascular, metabolic, severe and rare diseases, including neurological disorders, and cancer.  Isis' partner, Genzyme, is commercializing Isis' lead product, KYNAMRO®, in the United States and other countries for the treatment of patients with homozygous FH.  Isis' patents provide strong and extensive protection for its drugs and technology.  Additional information about Isis is available at www.isispharm.com .

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