Study supports early antiviral therapy in patients with moderate–high HBV viral load

Early treatment with tenofovir alafenamide appears to lower the risk of serious liver-related adverse events in patients with noncirrhotic chronic hepatitis B virus (HBV) infection and moderate or high viraemia, regardless of alanine aminotransferase (ALT) concentrations, according to interim data from the ATTENTION trial conducted in South Korea.

The analysis included 734 adult patients between 40 and 80 years of age who had serum HBV DNA concentrations of 4–8 log₁₀ IU/mL and ALT concentrations lower than 70 U/L for males and 50 U/L for females. These patients were randomly assigned to receive either oral tenofovir alafenamide at 25 mg daily (n=369) or no antiviral treatment (observation; n=365).

The primary endpoint was a composite of hepatocellular carcinoma, hepatic decompensation (portal hypertensive complications including ascites, gastro-oesophageal varices, or Child-Pugh score of ≥7), liver transplantation, or death from any cause, evaluated in the intention-to-treat population. Safety was assessed in all randomly assigned participants who received at least one dose of the study treatment. The interim analysis was prespecified at 4 years after enrolment of the first participant.

Over a median follow-up of 17.7 months, the primary endpoint occurred in 11 patients, including two in the tenofovir alafenamide arm (both hepatocellular carcinoma) and nine in the observation arm (seven hepatocellular carcinoma, one hepatic decompensation, and one death), translating to an incidence rate of 0.33 and 1.57 per 100 person-years, respectively.

Compared with observation, treatment with tenofovir alafenamide was associated with a 79-percent reduction in the risk of the composite endpoint (hazard ratio, 0.21, 97.5 percent confidence interval, 0.04–1.20; p=0.027). The observed difference between the treatment arms did not meet the predefined criteria for early termination of the trial.

Serious adverse events, with the exception of the composite endpoints, were recorded in 23 (6 percent) patients in the tenofovir alafenamide arm and in 24 (7 percent) in the observation arm.