Background: Given their high efficacy, entecavir (ETV) and tenofovir (TDF), are the recommended first-line therapies for chronic hepatitis B, but it is not clear whether the efficacy reported from pivotal trials is similar to the outcomes seen in routine practice.
Goals: Our goal was to examine the treatment outcomes of antiviral therapy in such setting.
Patients and methods: We conducted a retrospective study of 557 consecutive treatment-naive patients who started either ETV (n=443) or TDF (n=114) at 3 US liver clinics between January 2005 and 2012. Primary study endpoint was complete viral suppression (CVS) rate (hepatitis B virus DNA<40 IU/mL).
Results: The majority of patients in both ETV and TDF groups were Asians, hepatitis B e antigen (HBeAg) negative, male, and with similar pretreatment alanine aminotransferase and hepatitis B virus DNA levels. Similar proportions of patients in the ETV and TDF groups achieved CVS at 24 months: 87.7% versus 87.0%, respectively. Cumulative rates of virological breakthrough in the ETV and TDF groups were 1.0% versus 4.8% (P=0.26) and 3.7% versus 9.8% (P=0.04) at month 12 and 24, respectively; and all were associated with medication nonadherence. Cumulative rate of medication nonadherence was lower in the ETV than TDF group: 4.6% versus 7.8% at month 12 and 8.9% versus 16.9% at month 24, respectively.
Conclusions: Patients treated with either ETV or TDF achieve a similar rate of CVS at 24 months. The primary contributor to suboptimal response was medication nonadherence. Attention to medication adherence is needed in a routine clinical setting.