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. Aim 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.