Viral Kinetics Study of Telbivudine and Entecavir in Adults With Chronic Hepatitis B

Change in Mean HBV DNA Level

Baseline HBV DNA is defined as the last pre-dose assessment of HBV DNA.HBV DNA reductions, considered as the repeated measures, from baseline to Weeks 2, 4, 8.

Time frame: Baseline (day 1) to Weeks 2, 4, 8

The Area Under the Curve (AUC) of HBV DNA Change.

In AUC efficacy analyses, all the visits from baseline to Week 12 visit (including the planned and the repeated) with a non-missing HBV DNA level were included.

Time frame: From Baseline to Week 12

Change in Alanine Aminotransferase (ALT) Levels

Time frame: From Baseline to Week 12

Characterization of Very Early Viral Kinetics: Estimation of Viral Clearance

Viral kinetic parameters were estimated with a bi-phasic mathematical model: V(t) = (1-ε)pI(t) - cV(t) I(t) = (1- η)TV(t) - δI(t) V serum viral load, I productively infected cells, ε efficiency factor of blocking virus production, p viral production rate, c viral clearance rate, η efficiency factor of blocking de novo infection, β de novo infection rate, T uninfected target cells, δ rate of infected cell loss. Maximum-likelihood estimation for the viral kinetic parameters entailed fitting a nonlinear differential equation system via the least-squares approach from serum HBV DNA data.

Time frame: Baseline to 12 weeks

Characterization of Very Early Viral Kinetics: Estimation of the Rate of Infected Cell Loss

Viral kinetic parameters were estimated with a bi-phasic mathematical model: V(t) = (1-ε)pI(t) - cV(t) I(t) = (1- η)TV(t) - δI(t) V serum viral load, I productively infected cells, ε efficiency factor of blocking virus production, p viral production rate, c viral clearance rate, η efficiency factor of blocking de novo infection, β de novo infection rate, T uninfected target cells, δ rate of infected cell loss. Maximum-likelihood estimation for the viral kinetic parameters entailed fitting a nonlinear differential equation system via the least-squares approach from serum HBV DNA data.