Tenofovir alafenamide for hepatitis B virus infection including switching therapy from tenofovir disoproxil fumarate

Abstract

Background and Aim: Tenofovir alafenamide (TAF) is a new prodrug of tenofovir, enabling treatment of patients with hepatitis B virus (HBV) infection at a lower dose than tenofovir disoproxil fumarate (TDF), via more efficient delivery of tenofovir to the hepatocytes. We compared the efficacy and safety of TDF and TAF and investigated switching from TDF to TAF therapy. Methods: Consent for TDF and TAF therapy was obtained from 117 and 67 patients from August 2014 to January 2018. In total, 45 and 14 patients were administered with TDF and TAF, respectively, as naïve therapy, and 36 patients were switched from TDF to TAF. The antiviral effects and renal function safety were assessed. Results: At week 48, the antiviral effects on patients receiving TDF and TAF as naïve therapy were similar in terms of reduction of HBV DNA (À5.6 ± 1.8 logIU/ml vs À5.0 ± 1.7 log IU/ml; P = 0.34) and hepatitis B surface antigen (À0.29 ± 0.64 logIU/ml vs À0.15 ± 0.42 logIU/ml; P = 0.71) levels. A significant decrease in the estimated glomerular filtration rate (eGFR) was seen at 48-week TDF treatment (À5.34 ± 7.69 ml/min/ 1.73 m 2 ; P < 0.001). Switching from TDF to TAF did not increase the HBV DNA or hepatitis B surface antigen at 24 weeks. Although the eGFR worsened during TDF therapy (À7.32 ± 4.87 ml/min/1.73 m 2 ), it improved significantly at week 4 (+3.93 ± 6.18 ml/ min/1.73 m 2 ; P = 0.008) and week 24 (+2.89 ± 4.26 ml/min/1.73 m 2 ; P = 0.020) after switching from TDF to TAF. Conclusion: Tenofovir disoproxil fumarate and TAF showed adequate antiviral effects as naïve therapies. Furthermore, switching from TDF to TAF therapy contributed to the maintenance of the antiviral effect and recovery of renal dysfunction.

Short‑term efficacy after switching from adefovir dipivoxil and tenofovir disoproxil fumarate therapy to tenofovir alaferamide for chronic hepatitis&nbsp;B

“…Furthermore, since complete eradication of HBV is exceedingly difficult with current treatments, continuous treatment is required. Based on previous reports and the present study, which found an improvement in a short period of time, switching to TAF in patients with renal and tubular dysfunction appears to be effective regardless of previous NA administration duration ( 43 , 44 ). Therefore, switching to TAF should be considered, even in patients treated with NAs who have not experienced side effects.…”

“…A real-world study also reported that switching from TDF to TAF significantly reduced tubular dysfunction markers, including the U-BMG/Cr and retinol-binding protein-creatinine ratio in 3 months ( 43 ). A previous study also reported that not only tubular dysfunction markers, but also eGFR, significantly improved 1 and 6 months after switching from TDF to TAF ( 44 ).…”

Hepatitis B surface antigen reduction as a result of switching from long‐term entecavir administration to tenofovir

“…It is necessary to verify these findings in a bigger number of patients, and to examine long‐term therapeutic effects past 1 year. We previously reported that the therapeutic effects of TAF and TDF in naïve patients were comparable, and the HBsAg reduction by TAF and TDF was analyzed in the same group in this study. However, considering it has not sufficiently been verified whether the treatment effect of switching is equivalent, it is necessary to compare effects between TAF and TDF in a large cohort.…”

Detectable HBV DNA during nucleos(t)ide analogues stratifies predictive hepatocellular carcinoma risk score

“…Recently, tenofovir alafenamide (TAF), which was designed to exhibit greater plasma stability compared with TDF, was approved for clinical application. TAF is as effective as TDF and leads to continuous improvement in renal and bone safety in the treatment of patients with chronic hepatitis B (CHB) 12 – 15 . Reports of the reduction of the risk of HCC development induced by TAF are scarce, because of their short observation periods.…”