These new data show that patients who received Viread for up to 96 weeks experienced sustained suppression of hepatitis B virus (HBV) levels in the blood (91% and 78% for Studies 102 and 103, respectively). The studies also show that all Hepsera-treated patients whose HBV levels were suppressed at week 48 maintained viral suppression after rolling over to Viread, while Hepsera-treated patients with HBV DNA levels above 400 copies/mL at week 48 experienced significant viral suppression after rolling over to Viread.
Additionally, by week 96 of Study 103, 6% of all patients continuing treatment in both groups experienced ‘s’ antigen (HBsAg) loss, which contributes to resolution of chronic hepatitis B infection (HBsAg seroconversion rates were 4% among patients originally randomized to receive Viread and 5% for patients who rolled over from Hepsera). No mutations associated with resistance to Viread were reported among patients receiving Viread monotherapy for up to 96 weeks or in Hepsera-treated patients who rolled over to Viread.
Studies 102 and 103 were multi-center, randomized, double-blind Phase III clinical trials comparing Viread to Hepsera among patients with compensated liver disease and HBeAg-negative presumed pre-core mutant (n=375) and HBeAg-positive (n=266) chronic hepatitis B, respectively. Patients in both studies were originally randomized to receive Viread or Hepsera (adefovir dipivoxil). After the completion of 48 weeks of randomized blinded therapy, all eligible patients were rolled over to open-label Viread monotherapy.
Patrick Marcellin, principal investigator of Study 102, said: “In this study, Viread produced a significant and sustained effect over two years of treatment with no evidence of resistance, which is a substantial clinical finding. Additionally, patients in this study taking Hepsera were rolled over to Viread without new safety signals and without compromising the efficacy of anti-HBV treatment.”