Switching to tenofovir alafenamide from entecavir improves HBV suppression

Complete suppression of hepatitis B virus (HBV) has increased from 91.9 percent at tenofovir alafenamide (TAF) switch following use of entecavir for an average of 6 months to 97.2 percent at 96 weeks later, according to a study.

The authors enrolled entecavir-treated (≥12 months) chronic hepatitis B patients who switched to TAF in routine practice at 15 centres in the US, Korea, Japan, and Taiwan. Complete viral suppression rate (HBV DNA <20 IU/mL) was the primary endpoint.

A total of 425 patients (mean age 60.7±13.2 years) were analysed, of whom 60 percent were men, 90.8 percent were Asians, 20.7 percent had diabetes, 27 percent were hypertensive, 14.8 percent had cirrhosis, and 8.3 percent had hepatocellular carcinoma. The mean entecavir use prior to TAF switch was 6.16±3.17 years, while the mean baseline estimated glomerular filtration rate (eGFR) was 89±19 mL/min/1.73 m² (chronic kidney disease [CKD] stage 1, 55.6 percent; CKD stage 2, 35.7 percent, CKD stage 3–5, 8.8 percent).

The rate of complete viral suppression rose from 91.90 percent at TAF switch (90.46 percent at 24 weeks before switch) to 95.57 percent and 97.21 percent at 48 (p=0.03) and 96 weeks after (p=0.02).

Over the 96 weeks following TAF switch, mean HBV DNA (p<0.001) decreased but not alanine aminotransferase or CKD stage. Between the switch and 96-week follow-up, 11 percent (26/235) of CKD stage 1 patients worsened to stage 2 and 8 percent (12/151) of stage 2 patients to stages 3–5; on the other hand, 18 percent (27/151) of CKD stage 2 patients migrated to stage 1 and 19 percent (7/37) from stages 3–5 to stage 2.

Multivariable generalized estimated equation analysis revealed the association of baseline eGFR, age (p<0.001), and CKD stage 2 and 3–5 (compared to stage 1; p<0.001 for both) with lower follow-up eGFR, adjusted for age, sex, diabetes, hypertension, and cirrhosis.