Treatment outcomes amongst previously antiretroviral-naïve HIV-infected patients starting lopinavir/ritonavir-containing antiretroviral regimens at the Royal Free Hospital*

Objective To describe outcomes in patients starting first-line antiretroviral regimens including lopinavir/ritonavir (LPV/r) in a routine clinic setting. Methods Previously naive patients starting LPV/r-containing antiretroviral therapy were included in the study. Virological failure was defined as the first of two viral loads >500 HIV-1 RNA copies/mL more than 6 months after starting LPV/r. Cumulative percentages experiencing virological failure were calculated using Kaplan–Meier methods. Results A total of 195 individuals had a median follow-up time of 1.7 years. At 48 weeks, 87.9, 77.4 and 71.6% of patients with pretreatment CD4 counts of 200 cells/μL, respectively, remained on LPV/r. By 48, 72 and 96 weeks, 2.2, 3.0 and 5.0% of patients, respectively, had experienced virological failure, ignoring treatment changes but censoring follow-up at discontinuation of all antiretrovirals; these percentages became 24.0, 33.7 and 42.3% when LPV/r discontinuation was considered as virological failure. Censoring those who stopped LPV/r with a viral load 50 copies/mL gave 12.1, 14.6 and 17.0% virological failure at 48, 72 and 96 weeks, respectively. Median CD4 count increases at 24, 48 and 72 weeks were 167, 230 and 253 cells/μL, respectively. Conclusions Few patients experienced virological failure whilst on a LPV/r-based regimen, although it was not uncommon for patients in our clinic with higher baseline CD4 counts to discontinue LPV/r.