Induction therapy with trizivir plus efavirenz or lopinavir/ritonavir followed by trizivir alone in naive HIV-1-infected adults

Abstract

Induction-maintenance strategies were associated with a low response rate. We compared the virological response with two different induction regimens with trizivir plus efavirenz or lopinavir/ritonavir. A randomized, multicentre, open-label clinical trial with 209 antiretroviral-naive HIV-infected patients assigned to trizivir plus either efavirenz or lopinavir/ritonavir during 24-36 weeks. Patients reaching undetectable plasma viral loads during induction entered a 48-week maintenance on trizivir alone. The primary endpoint was the proportion of patients without treatment failure at 72 weeks using an intent to treat (ITT) analysis (switching equals failure). Patients were randomly assigned (efavirenz 104; lopinavir/ritonavir 105), and 114 (55%) entered the maintenance phase (efavirenz 54; lopinavir/ritonavir 60). Baseline characteristics were balanced between groups. The response rate at 72 weeks was 31 and 43% (ITT analysis, P = 0.076) and 63 and 75% (on-treatment analysis, P = 0.172) in the efavirenz and lopinavir/ritonavir arms, respectively. Virological failure occurred in 27 patients: six during induction (efavirenz, three; lopinavir/ritonavir, three; P = 1.0) and 21 during maintenance (efavirenz, 14; lopinavir/ritonavir, seven; P = 0.057). Thirty-four patients in the efavirenz arm switched treatment because of adverse events compared with 25 in the lopinavir/ritonavir arm (P = 0.17). Trizivir plus either efavirenz or lopinavir/ritonavir followed by maintenance with trizivir achieved a low but similar response at 72 weeks, with a high incidence of adverse events leading to drug discontinuation during the induction phase in both arms. The study showed a trend towards an increased virological failure rate in the efavirenz arm during the maintenance phase.