Partial HBV Response to Entecavir Still Tied to Favorable Outcomes

SAN FRANCISCO, CA—Partial virologic response to entecavir does not affect long-term clinical outcomes in patients with chronic hepatitis B virus (HBV) infection, according to a study presented at The Liver Meeting® 2015.

Partial virologic response is not related to hepatocellular carcinoma (HCC) or occurrence of liver-related events, including patients with cirrhosis. 

These findings suggest that “early rescue therapy for patients with partial virologic response might not be urgent unless patients are at high risk of hepatic decompensation and HCC development,” reported lead study author Kyu Sik Jung, MD, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.

Patients with treatment-naïve chronic HBV who received entecavir 0.5mg/day for at least 1 year were assessed for virologic response at 48 weeks. Partial virologic response was defined as a decrease in HBV-DNA titer of more than 1 log₁₀IU/mL with residual serum HBV-DNA by real time-polymerase chain reaction (PCR). Complete virologic response was an undetectable serum HBV-DNA (<20 IU/mL).

The primary endpoint was HCC occurrence; the secondary endpoint was liver-related events, defined as cirrhotic complication, HCC, liver transplantation, or liver-related mortality.

Of the 868 patients enrolled, 577 were analyzed; 209 had liver cirrhosis; 38 decompensated liver cirrhosis; and 31, HCC.

When the patients with and without HCC were compared, significant differences were observed for age, 61.0 years for patients with HCC vs. 49.4 years for those without (P<0.001); liver cirrhosis, 21 vs. 148 (P<0.001); HBeAg positivity (P=0.017); and persistent ALT elevation at 48 weeks (P=0.015), respectively.

Univariate analysis found that independent risk factors for HCC occurrence were age (P<0.001) and liver cirrhosis (P<0.001) and, for occurrence of liver-related events, age (P<0.001), persistent ALT elevation at 48 weeks (P=0.039), and liver cirrhosis (P<0.001). On multivariate analysis, age and liver cirrhosis persisted as independent risk factors for HCC and liver-related events.

The investigators found no significant difference between the partial virologic response and complete virologic response groups for HCC or liver-related events, including in a subgroup with cirrhosis (all P<0.05).

The cumulative incidence rate of complete virologic response was 43.4% at 2 years, 67.7% at 3 years, and 85.7% at 5 years, Dr. Jung reported. “Most patients with partial virologic response achieved ALT normalization after 1 year of treatment with entecavir.”