Tenofovir alafenamide and tenofovir disoproxil fumarate reduce incidence of hepatocellular carcinoma in patients with chronic hepatitis B

Abstract

<h3>Background and Aims</h3><p>Antiviral therapy may attenuate the risk of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B (CHB). We aimed to explore how tenofovir alafenamide (TAF) and tenofovir disoproxil fumarate (TDF) affect HCC risk in CHB patients.</p><h3>Methods</h3><p>The REACH-B, aMAP, and mPAGE-B models were utilized to assess HCC risk in CHB patients from two global randomized controlled trials evaluating the impact of TAF vs. TDF treatment. Standard incidence ratios (SIRs) were calculated using data from the REACH-B model as a ratio of observed HCC cases in the TAF- or TDF-treated patients vs. predicted HCC cases for untreated historical controls. Proportions of treated patients shifting aMAP and mPAGE-B risk categories between baseline and Week 240 were calculated.</p><h3>Results</h3><p>Of the 1,632 patients (TAF, n=1,093; TDF, n=539) followed for up to 300 weeks, 22 HCC cases developed. Those receiving TAF had an SIR that was lower compared to the SIR of individuals receiving TDF: 0.32 (p<0.001) vs. 0.56 (p=0.06). In the general study population, individuals without cirrhosis at baseline had an SIR that was lower compared to the SIR of individuals with cirrhosis at baseline: 0.37 (p<0.001) vs. 0.58 (p=0.15). Of the patients who were low risk for HCC at baseline, the majority (97%) remained low risk by mPAGE-B and aMAP scoring by Week 240. Among those at medium or high risk at baseline, substantial portions shifted to a lower risk category by Week 240 (mPAGE-B: 22% and 42%; aMAP: 39% and 63%).</p><h3>Conclusions</h3><p>This evaluation provides evidence that treatment with TAF or TDF can reduce HCC risk in CHB patients, particularly in patients without cirrhosis.</p><h3>Lay Summary</h3><p>In this study, we used three models to predict the likelihood that patients with chronic (long-term) hepatitis B would also develop hepatocellular carcinoma (HCC), a deadly form of liver cancer. We found that patients who received treatment with antiviral medications, TAF or TDF, had a lower risk of HCC than if they had been left untreated. This benefit of antiviral treatment was especially notable in patients without substantial liver damage (cirrhosis).</p>