Looking at the Tenofovir Data Another Way

In last Friday’s post, this blog reviewed 5-year data on tenofovir usage which showed that tenofovir could reverse fibrosis/cirrhosis.  Another study using the same cohort examined the efficacy of tenofovir in patients with high viral load (HVL) at baseline (Hepatology 2013; 58: 505-13).

From an initial total of 641 patients enrolled in GS-US-174-0102 (n=375) and GS-US-174-0103 (n=266), the authors identified 129 (20%) with HVL.  HVL was defined as having ≥9 log10 copies/mL.  After an initial 48 weeks of randomization between tenofovir (HVL n=82) or adefovir (HVL n=47), patients received an additional 192 weeks of therapy with tenofovir in an open label extension.

Results:

  • By week 240, 98.3% of HVL and 99.2% of non-HVL patients on treatment achieved HBV DNA <400 copies/mL
  • High HVL patients took longer to achieve undetectable HBV DNA, but by week 96 the results were similar in both groups
  • Patients who received tenofovir during the initial 48 weeks achieved undetectable HBV DNA quicker than those who had received adefovir initially
  • There were similar rates of histologic regression in both HVL and non-HVL patients

This study evaluated only patients in the ‘immune clearance’ phase of HBV and therefore cannot be extrapolated to those in the immune tolerant phase.