Chronic Hepatitis B Overview
Hepatitis B, an infectious disease caused by the hepatitis B virus (“HBV”), affects the liver and occurs in both acute and chronic modalities. Patients who test positive for HBsAg, an HBV surface protein antigen, for more than six months are said to be chronic and are at risk of developing liver disease. The virus is transmitted by exposure to infectious blood or bodily fluid but is preventable by vaccination.
Currently there are about 350 million chronic HBV patients worldwide and 786,000 reported HBV-related deaths in 2010. The United States is the largest individual market with the highest absolute growth rate of HBV patients at around 15.4% through 2033 and around 9% growth in much of Europe.
Individuals with chronic hepatitis B are significantly more prone to developing cirrhosis of the liver and liver cancer. 20%-30% of all chronic hepatitis B patients develop these complications, and individuals with chronic hepatitis B are 100 times more likely to develop liver cancer than non-infected individuals. The limited efficacy of treatments for liver cancer and low survival rate (15%) mean that any treatment targeted at suppressing HBV replication before these complications arise is important to increase longevity.
John Sullivan-Bolyai on TXL™ (formerly CMX157) as a potential cornerstone therapy for Hepatitis B.
Curing Hepatitis B with Combination Therapy
Curing hepatitis B is at the forefront of ContraVir’s research and business strategy. Similar to other major viral infections like hepatitis C and HIV, experts now believe that combining different drugs that can work together against HBV into a single regimen will be the most likely way to achieve a cure. A cure for hepatitis B may be through full eradication of the virus from the body (similar to hepatitis C) or what is known as a “functional cure” whereby viral levels are minimal and any negative effects are eliminated with continuous therapy (similar to HIV).
The mechanisms of action of ContraVir’s two HBV drugs TXL™ and CRV431 are distinct and complementary to each other, inhibiting viral replication at multiple different points in the HBV life cycle. Both drugs are next-generation derivatives of proven antiviral compounds and have demonstrated potentially best-in-class potency in vitro. Higher potency helps minimize the dose required for antiviral activity, as well as potentially reduce any side effects. It also maximizes the opportunity to use TXL™ and CRV431 in combination with each other and additional molecules to create a uniquely powerful and potentially curative anti-HBV regimen. ContraVir is focused on advancing its HBV portfolio and working towards a functional cure for hepatitis B.