HIV-1 drug resistance and second-line treatment in children randomized to switch at low versus higher RNA thresholds

BACKGROUND: The PENPACT-1 trial compared virologic thresholds to determine when to switch to second-line antiretroviral therapy (ART). Using PENPACT-1 data, we aimed to describe HIV-1 drug resistance accumulation on first-line ART by virologic threshold. METHODS: PENPACT-1 had a 2 × 2 factorial design, randomizing HIV-infected children to start protease inhibitor (PI) versus nonnucleoside reverse transcriptase inhibitor (NNRTI)-based ART, and switch at a 1000 copies/mL versus 30,000 copies/mL threshold. Switch criteria were not achieving the threshold by week 24, confirmed rebound above the threshold thereafter, or Center for Disease Control and Prevention stage C event. Resistance tests were performed on samples ≥1000 copies/mL before switch, resuppression, and at 4-years/trial end. RESULTS: Sixty-seven children started PI-based ART and were randomized to switch at 1000 copies/mL (PI-1000), 64 PIs and 30,000 copies/mL (PI-30,000), 67 NNRTIs and 1000 copies/mL (NNRTI-1000), and 65 NNRTI and 30,000 copies/mL (NNRTI-30,000). Ninety-four (36%) children reached the 1000 copies/mL switch criteria during 5-year follow-up. In 30,000 copies/mL threshold arms, median time from 1000 to 30,000 copies/mL switch criteria was 58 (PI) versus 80 (NNRTI) weeks (P = 0.81). In NNRTI-30,000, more nucleoside reverse transcriptase inhibitor (NRTI) resistance mutations accumulated than other groups. NNRTI mutations were selected before switching at 1000 copies/mL (23% NNRTI-1000, 27% NNRTI-30,000). Sixty-two children started abacavir + lamivudine, 166 lamivudine + zidovudine or stavudine, and 35 other NRTIs. The abacavir + lamivudine group acquired fewest NRTI mutations. Of 60 switched to second-line, 79% PI-1000, 63% PI-30,000, 64% NNRTI-1000, and 100% NNRTI-30,000 were <400 copies/mL 24 weeks later. CONCLUSIONS: Children on first-line NNRTI-based ART who were randomized to switch at a higher virologic threshold developed the most resistance, yet resuppressed on second-line. An abacavir + lamivudine NRTI combination seemed protective against development of NRTI resistance

First-line antiretroviral therapy with a protease inhibitor versus non-nucleoside reverse transcriptase inhibitor and switch at higher versus low viral load in HIV-infected children: an open-label, randomised phase 2/3 trial.

BACKGROUND: Children with HIV will be on antiretroviral therapy (ART) longer than adults, and therefore the durability of first-line ART and timing of switch to second-line are key questions. We assess the long-term outcome of protease inhibitor and non-nucleoside reverse transcriptase inhibitor (NNRTI) first-line ART and viral load switch criteria in children. METHODS: In a randomised open-label factorial trial, we compared effectiveness of two nucleoside reverse transcriptase inhibitors (NRTIs) plus a protease inhibitor versus two NRTIs plus an NNRTI and of switch to second-line ART at a viral load of 1000 copies per mL versus 30,000 copies per mL in previously untreated children infected with HIV from Europe and North and South America. Random assignment was by computer-generated sequentially numbered lists stratified by age, region, and by exposure to perinatal ART. Primary outcome was change in viral load between baseline and 4 years. Analysis was by intention to treat, which we defined as all patients that started treatment. This study is registered with ISRCTN, number ISRCTN73318385. FINDINGS: Between Sept 25, 2002, and Sept 7, 2005, 266 children (median age 6.5 years; IQR 2.8-12.9) were randomly assigned treatment regimens: 66 to receive protease inhibitor and switch to second-line at 1000 copies per mL (PI-low), 65 protease inhibitor and switch at 30,000 copies per mL (PI-higher), 68 NNRTI and switch at 1000 copies per mL (NNRTI-low), and 67 NNRTI and switch at 30,000 copies per mL (NNRTI-higher). Median follow-up was 5.0 years (IQR 4.2-6.0) and 188 (71%) children were on first-line ART at trial end. At 4 years, mean reductions in viral load were -3.16 log(10) copies per mL for protease inhibitors versus -3.31 log(10) copies per mL for NNRTIs (difference -0.15 log(10) copies per mL, 95% CI -0.41 to 0.11; p=0.26), and -3.26 log(10) copies per mL for switching at the low versus -3.20 log(10) copies per mL for switching at the higher threshold (difference 0.06 log(10) copies per mL, 95% CI -0.20 to 0.32; p=0.56). Protease inhibitor resistance was uncommon and there was no increase in NRTI resistance in the PI-higher compared with the PI-low group. NNRTI resistance was selected early, and about 10% more children accumulated NRTI mutations in the NNRTI-higher than the NNRTI-low group. Nine children had new CDC stage-C events and 60 had grade 3/4 adverse events; both were balanced across randomised groups. INTERPRETATION: Good long-term outcomes were achieved with all treatments strategies. Delayed switching of protease-inhibitor-based ART might be reasonable where future drug options are limited, because the risk of selecting for NRTI and protease-inhibitor resistance is low. FUNDING: Paediatric European Network for Treatment of AIDS (PENTA) and Pediatric AIDS Clinical Trials Group (PACTG/IMPAACT).

Randomized controlled trial of feeding a concentrated formula to infants born to women infected by human immunodeficiency virus.

OBJECTIVE: We tested the hypothesis that concentrated formula (CF) begun within the first 2 weeks of life increases growth in infants born to human immunodeficiency virus (HIV)-infected mothers. MATERIALS AND METHODS: HIV-exposed infants from the United States, the Bahamas, and Brazil were randomized in a double-blind, controlled trial to receive either a CF (87 kcal/100 mL [26 kcal/oz]) or a standard formula (SF; 67 kcal/100 mL [20 kcal/oz]) for 8 weeks. This article presents results for infants who were not determined to be HIV infected based on testing at 4 weeks. Primary outcomes were safety, tolerability, and growth in weight and length. RESULTS: Two thousand ninety-seven infants were enrolled, of whom 1998 were uninfected and had study formula dispensed. At weeks 4 and 8, uninfected infants receiving CF showed higher energy intake than those who were receiving SF (P < 0.001). By week 8, uninfected infants assigned to CF weighed more than infants receiving SF. There were no consistent differences in measures of tolerability, and rates of discontinuation or perceived formula intolerance were similar between treatment groups. CONCLUSIONS: A CF is well tolerated and results in increased weight gain compared with SF. Until the HIV status of an infant is reliably determined, early introduction of a CF in HIV-exposed children may have beneficial effects on growth. The role of early nutritional intervention remains to be determined for individuals living in countries with endemic malnutrition for whom formula feeding is a viable option.