Efficacy of different nucleoside analog rescue therapies for entecavir-resistant chronic hepatitis B patients

Entecavir (ETV) is recommended as a first-line anti-HBV treatment. However, many chronic hepatitis B patients initiate anti-HBV treatment such as lamivudine and telbivudine with low genetic barriers in China, which leads to compensatory mutations and increases the rate of ETV resistance. The management of ETV resistance in China is an essential clinical issue. Patients from 2011 to 2017 with nucleos(t)ide analog resistance were screened and 72 patients with ETV resistance were included. These patients received different rescue therapies including an ETV and adefovir (ADV) combination therapy group (n = 25), a tenofovir (TDF) monotherapy group (n = 27), and an ETV and TDF combination therapy group (n = 20). Virologic, biochemical, and serologic responses were compared among the three groups. The rate of ETV resistance among all HBV-resistant variants increased from 6.04% in 2011 to 15.02% in 2017. TDF monotherapy and TDF combination groups showed similar rates of negative HBV DNA at 48 weeks (74.07% vs 70.00%, P > 0.05), while the ETV and ADV group showed the worst virologic response (28.00%). Also, TDF monotherapy and TDF combination therapy showed similar decline of HBV DNA at weeks 12, 24, and 48. There was no significant difference in the rates of HBeAg clearance, ALT normalization, and abnormal renal function among the three groups. TDF monotherapy showed a comparable virologic response to TDF and ETV combination therapy and a better virologic response than ETV and ADV combination therapy. Thus, TDF monotherapy is the preferred rescue therapy for ETV resistance.