Due to the considerable unmet medical need of patients with chronic hepatitis B, Gilead has initiated an early access program to make its investigational drug, adefovir dipivoxil 10 mg, available to those patients with lamivudine-resistant chronic hepatitis B at risk of disease progression. Protocol GS-01-550 provides access to patients with lamivudine-resistant hepatitis B virus who are in need of an alternative treatment to suppress HBV DNA replication and prevent progressive liver disease.