Clevudine is an antiviral drug for the treatment of hepatitis B. Clevudine is already approved for HBV in South Korea and the Philippines. It is marketed by Bukwang pharmaceuticals in South Korea under the tradenames Levovir and Revovir.
Under license from Bukwang, Pharmasset

Pharmasset

Pharmasset Inc. is a pharmaceutical company based in Princeton, New Jersey in the United States. The company develops antiviral drugs for HIV , hepatitis B , and hepatitis C. In November 2011, Pharmasset was acquired by Gilead for $11 billion.-History:Pharmasset was founded in 1998 by Dr. Raymond...

 was developing the drug, but its phase III clinical trial (international, multicenter, randomized, double-blind, 96 week QUASH studies) was terminated due to some myopathy cases in patients.

It is a nucleoside analog.