Prospective Analysis of Safety and Efficacy of Tenofovir Alafenamide Fumarate (TAF) in European Real-World Patients with Chronic Hepatitis B: A Single-Centre Real-Word Cohort Study

<b>Background:</b> Tenofovir alafenamide (TAF) is a novel prodrug of tenofovir for the treatment of chronic hepatitis B (CHB) that has shown a favourable renal safety profile while offering suppression of HBV DNA similar to tenofovir disoproxil fumarate (TDF). We aimed to study changes in markers of HBV replication and renal function in a real-world setting in European patients. <b>Methods:</b> In our prospective single-arm, non-interventional observational study, HBeAg-positive and HBeAg-negative patients with chronic HBV mono-infection receiving TAF as their first or following line treatment were enrolled. HBV DNA, HBsAg, markers of bone metabolism, and renal function were determined at baseline and every consecutive 3 months. <b>Results:</b> A total of 50 patients (70% male) were included. The mean duration of TAF treatment was 18 (3-36) months. In 20 patients with detectable HBV DNA at baseline, median serum levels of HBV DNA log₁₀ changed from 2.33 (0.766-6.47) to 1.04 IU/mL at the end of observation and became undetectable in 11 patients. Median HBsAg log₁₀ decreased from 3.37 (0.88-5.10) to 2.39 (1.52-4.19) IU/mL. During the entire observation period, the renal function parameters remained stable in patients with normal renal function and even in those with renal dysfunction. Mild adverse events were reported by 14 patients (28%). <b>Conclusions:</b> TAF was a safe and effective treatment, also in patients with decreased renal function.