OBJECTIVES: Tenofovir disoproxil fumarate (TDF) is effective for treatment of Hepatitis B but may be associated with bone loss and kidney problems in susceptible individuals. Tenofovir alafenamide (TAF) is a novel pro-drug formulation with an improved safety profile for bone loss and renal injury. Here, we assess the clinical experience with TAF for Hepatitis B in the US.

METHODS: The TRIO HBV Registry, consisting of 1078 enrolled patients from 6 academic and 4 community-based centers serving 17 US States, was created to understand real-world HBV treatment. Data presented here are limited to 250 registry patients who initiated TAF between Nov 2016 and Apr 2018, received ≥6 months of TAF therapy, and were followed up to 18 months.

RESULTS: Characteristics of the study population: median age 52 years, BMI 24.3 kg/m2, male (147/250, 59%), Asian ethnicity (220/250, 88%), HBeAg positive (54/250, 22%), osteopenia/osteoporosis (47/250, 19%), and FIB-4 >3.25 (17/250, 7%). Mean and median TAF duration was 13 months as of data collection. 233/250 (93%) of patients receiving TAF switched from TDF (214/233, 92%), entecavir (16/233, 7%), or other therapies (3/233, 1%). HBV DNA suppression (<2000 IU/ml) increased from 93% (233/250) patients at baseline to 99% after 6 or 12 months TAF (249/250, p=0.001). In paired comparisons, mean eGFR increased 5% from baseline 85.7 to 90.1 ml/min (p<0.001) after 6 months of TAF therapy (n=213) and 4% from baseline 86.9 to 90.5 ml/min (p=0.001) after 12 months of TAF (n=158). Normal ALT (≤29 U/L females, ≤35 U/L males) increased from 71% patients at baseline to 86% after 6 months TAF (n=219, p=0.001) and from 69% at baseline to 87% after 12 months TAF (n=147, p=0.001).

CONCLUSIONS: In US, clinical practice experience with TAF indicates effective HBV suppression and improved renal function and ALT normalization.