Letter: First-line monotherapies for chronic hepatitis B - indirect comparison between entecavir and tenofovir.

SIRS, In the debate on the use of nucleotide/nucleoside analogues in chronic hepatitis B (CHB), recent guidelines have pointed out that drug-resistant mutations are more frequent with lamivudine, telbivudine or adefovir. For this reason, only entecavir or tenofovir is recommended as first-line monotherapy. 2 As there are no head-to-head comparisons between entecavir and tenofovir, we performed a network metaanalysis of randomised trials, which was focused on patients with compensated liver disease. The end-point of our analysis was the rate of virological response at 1 year. Our meta-analytical methods were the same as those of a previous study 4 (see also our Data S1). A total of two trials were suitable for our analysis. Figure 1 summarises its main results. The direct comparison of entecavir vs. adefovir (1 trial) was associated with a response rate ratio (RRR) of 3.07 [95% confidence interval (CI): 1.41–6.69] with a number need to treat [NNT] of 3 (95% CI: 1–17). Likewise, the direct comparison of tenofovir vs. adefovir (1 trial) had a RRR of 5.71 (95% CI: 3.35–9.73) and a NNT of 1 (95% CI: 1–3). Using the data of these direct comparisons, our network meta-analysis generated a RRR for the indirect comparison of tenofovir vs. entecavir of 1.86 (95% CI: 0.72–4.78) with a NNT of 3 (95% CI: 1–∞). These results clearly show that no difference in effectiveness exists between tenofovir and entecavir. In conclusion, differences in effectiveness between these two agents are not demonstrated by our analysis, and are very unlikely to exist. As a result, other factors (mainly related to patient characteristics) must guide the =