Safety and Effectiveness of Tenofovir Alafenamide in Usual Clinical Practice Confirms Results of Clinical Trials: TARGET-HBV

HERACLIS-TAF: a multi-centre prospective cohort study on 2-year safety and efficacy of tenofovir alafenamide in patients with chronic hepatitis B with renal and/or bone disorders or risks

BACKGROUND

Tenofovir alafenamide (TAF) has exhibited a favourable safety profile on estimated glomerular filtration (eGFR) and bone mineral density (BMD), but has not been extensively studied in patients with renal impairment and/or BMD disorders.

AIMS

To assess predictors of eGFR changes and other safety and efficacy outcomes during 24-month TAF therapy in patients with chronic hepatitis B with renal and/or BMD disorders/risks.

METHODS

Adult patients who started TAF at 13 clinics throughout Greece were prospectively included. Main exclusion criteria were hepatitis D, active malignancy and bisphosphonates recent use. MDRD formula was used for eGFR estimation.

RESULTS

TAF was initiated in 176 patients (91% switched from another agent). At 12 and 24 months, HBV DNA was undetectable in 97% and 100%, and ALT was normal in 96% and 95% of patients. Median ALT decreased from baseline to month 12/24 (p < 0.001). Mean eGFR decreased from previous treatment initiation to baseline (p < 0.001), increased at 12 months and remained stable at 24 months (p ≤ 0.001). An increase in eGFR of >3 ml/min at 12 month was observed in 50% of patients and was associated mainly with baseline eGFR 30-60 ml/min. In patients with baseline phosphate <2.5 mg/dl, mean serum phosphate increased at month-12/24 (p < 0.001). Median BMD did not change significantly from baseline to 12 months but improved at 24 months (p = 0.001).

CONCLUSIONS

In mostly switched patients with renal and/or BMD disorders/risks, eGFR improved after 12-24 months of TAF treatment, especially in patients with baseline eGFR 30-60 ml/min. TAF may also improve low serum phosphate, BMD and ALT, whereas it maintains or induces virological suppression.

Review article: switching patients with chronic hepatitis B to tenofovir alafenamide-a review of current data

BACKGROUND

The nucleos(t)ide analogues (NAs) entecavir (ETV), tenofovir disoproxil fumarate (TDF) and tenofovir alafenamide (TAF) are preferred treatment options for patients with chronic hepatitis B infection (CHB). However, resistance to ETV has been reported, especially with prior exposure to other NAs, and long-term TDF treatment has been associated with decline in renal function and loss of bone mineral density in some patients. Consequently, TAF may be preferable to ETV, TDF or other NAs in specific circumstances such as in patients with risk of bone or renal complications, elderly patients or those with previous NA experience.

AIM

To provide a summary of the available efficacy and safety data following switch to TAF from other NAs in patients with CHB in clinical studies and real-world settings.

METHODS

Literature searches were performed on PubMed and abstracts from three major international liver congresses between 2019 and 2021. Studies that included efficacy and/or safety data for patients with CHB switching from any NA to TAF were selected.

RESULTS

Thirty-six papers and abstracts were included in this narrative review. Switching from TDF to TAF maintained or improved virological and biochemical responses with improved bone and renal safety. Switching from ETV or other NAs to TAF maintained or improved virological and biochemical responses and varying results for bone and renal safety.

CONCLUSIONS

Switching to TAF appears to maintain or improve virological, biochemical and bone- and renal-related safety outcomes. These data support the concept of switching to TAF in some patients with CHB based on their individual circumstances.

Real-world experience of switching from tenofovir disoproxil fumarate to tenofovir alafenamide in patients with chronic hepatitis B: a retrospective study

Background

Tenofovir alafenamide (TAF) has good viral suppression efficacy and less adverse effect than tenofovir disoproxil fumarate (TDF). Real-world studies on the antiviral efficacy and safety of switching from TDF to TAF in patients with chronic hepatitis B (CHB) are limited.

Methods

This retrospective study included 167 nucleos(t)ide analogue (NA)-naive patients with CHB. All the patients received TDF at least 12 months before switching and TAF at least 12 months after switching at a single medical center. The Friedman test with Dunn–Bonferroni post hoc tests and repeated-measures analysis of variance was used to analyze the effect of complete viral suppression, alanine aminotransferase (ALT) level normalization, renal function changes, body weight, and body mass index in the periods before and after switching.

Results

The mean age and TDF treatment duration were 52 ± 11 years and 2.8 years (interquartile range, 1.51–5.15 years), respectively. The complete viral suppression rate was similar between the time of switching and 48 weeks after switching to TAF (77.8% vs 76%, P = 1.000). The percentage of alanine aminotransferase (ALT) normalization increased from 26.3% at TDF start to 81.4% (P < 0.001) at time of switching and 89.2% at 48 weeks after switching to TAF (P = 0.428). The median estimated glomerular filtration rate decreased from 100.09 mL/min/1.73 m² at TDF start to 91.97 mL/min/1.73 m² (P < 0.001) at the time of switching and stabilized at 48 weeks after switching to TAF (93.47 mL/min/1.73m², P = 1.000). The body weight decreased from 69.2 ± 12.2 kg at TDF start to 67.4 ± 12.1 kg (P < 0.001) at the time of switching to TAF and returned to 68.7 ± 12.7 kg (P < 0.001) 48 weeks thereafter. The body mass index (BMI) decreased from 25 ± 3.3 kg/m² at TDF start to 24.5 ± 3.3 kg/m² (P = 0.002) at the time of switching to TAF and returned to 25.1 ± 3.6 kg/m² (P < 0.001) 48 weeks thereafter.

Conclusions

Our study showed that switching to TAF from TDF had good antiviral effectiveness and stabilized renal function. The body weight and BMI decreased during TDF therapy and regained after switching to TAF.