Safety and antiviral response at 12 months of lopinavir/ritonavir therapy in human immunodeficiency virus-1-infected children experienced with three classes of antiretrovirals

Introduction. Many human immunodeficiency virus type 1 (HIV-1)-infected children have already failed treatment with 2 or even 3 classes of antiretrovirals. Coformulation of lopinavir with low dose ritonavir exhibits a potent antiretroviral effect. However, the data in heavily pretreated children are still scarce. This study evaluated the safety and effectiveness of combination therapy including lopinavir/ritonavir in children with prior exposure to all classes of oral antiretrovirals. Methods. This was an open label multicenter observational study, in which data were reviewed according to a standardized protocol. The study population included all HIV-1-infected children with virologic failure (HIV-1 RNA > 5000 copies/mL) followed in 12 Spanish hospitals for > 12 months, experienced with the 3 classes of oral antiretrovirals, in whom a lopinavir/ritonavir-containing regimen was started. Results. By March 2003, 45 patients had been treated with lopinavir/ritonavir for a median of 18 months (range, 3-28). The median age at baseline was 9.7 years (range, 4.3-17.1). The median times of prior treatment were 88 months (range, 31-145) with nucleoside reverse transcription inhibitors and 42 months (range, 19-63) with protease inhibitors. Twenty-five patients were classified as Centers for Disease Control and Prevention clinical category C. Median values for absolute and percentage CD4 at baseline were 501 (range, 6-1512) and 19% (range, 0.5-49), respectively, and plasma HIV- RNA was 5.0 log(10) copies/mL (range, 4.1-6.1). During follow-up, 11 (24%) children switched from liquid to solid formulation. At 48 weeks, the median values for absolute and percentage CD4 increased by 199 cells/mu L and 3%, respectively, and median plasma viral load declined 1.75 log(10) copies/mL. Forty-two percent of children achieved a plasma RNA of < 400 copies/mL (intent to treat analysis). Baseline genotypic resistance was available in 40 children. Nonresponders had 7.0 +/- 1.6 protease inhibitor-associated mutations at baseline compared with 4.8 +/- 1.7 in children achieving virologic suppression (P = 0.06). Adverse events were described in 18 children. Three children permanently discontinued and 4 transiently withdrew lopinavir/ritonavir. At 12 months, there were mild but not significant increases in plasma cholesterol and triglycerides. Conclusions. Lopinavir/ritonavir when given as part of salvage regimen is well-tolerated, although switching to pills is frequently required. The regimen has a potent and durable antiretroviral activity in most heavily pretreated children, despite the presence of multiple mutations to all classes of oral antiretrovirals.