Pharmaceutical company Gilead Sciences announced on Monday that its AIDS drug Viread had been approved by US authorities for the treatment of chronic Hepatitis B in adults.

The generic name of Viread is tenofovir. It has been available in the United States since 2001 and is widely used in the treatment of HIV infections. For the treatment of Hepatitis B, Viread would work by blocking an enzyme which the virus needs to replicate itself in the liver cells.

Another drug marketed by Gilead Sciences in the treatment of Hepatitis B is Hepsera which sold worth $90 million in the second quarter of 2008. The company also markets Truvada which is a combination of Viread and another HIV drug called Emtriva. The second quarter sales of Truvada stood at $516 million. According to industry experts, the market for Hepatitis B drugs is greatly underserved with Hepsara having just 44 percent of total market share.

Hepatitis B is a potentially fatal infection that can severely damage and even destroy the liver. According to estimates provided by Gilead, almost 400 million around the world suffer from this disease which is especially widespread in the Asian countries. Hepatitis B is also the leading cause of liver cancer, with around 1.2 million patients dying every year from serious complications.

-Kalyani Mookherji