Sep, 2015

HIV-1 Drug Resistance and Second-line Treatment in Children Randomized to Switch at Low versus Higher RNA Thresholds


Authors: Harrison L, Melvin A, Fiscus S, et al. For PENPACT-1 (PENTA 9PACTG 390) Study Team.

Published in: JAIDS 2015;70(1):42-53

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.



Apr, 2014

Using CD4 Percentage and Age to Optimize Pediatric Antiretroviral Therapy Initiation


Authors: Yin D., Warshaw M., Miller W., Castro H., Fiscus S., Harper L., Harrison L., Klein N., Lewis J., Melvin A., Tudor-Williams G., McKinney R.

Published in: Pediatrics, 2014;134(4):e1104-16

Background Quantifying pediatric immunologic recovery by highly active antiretroviral therapy (HAART) initiation at different CD4 percentage (CD4%) and age thresholds may inform decisions about timing of treatment initiation.

Methods HIV-1-infected, HAART-naive children in Europe and the Americas were followed from 2002 through 2009 in PENPACT-1. Data from 162 vertically infected children, with at least World Health Organization “mild” immunosuppression and CD4% <10th percentile, were analyzed for improvement to a normal CD4% (≥10th percentile) within 4 years after HAART initiation. Data from 209 vertically infected children, regardless of immune status, were analyzed for CD4% outcomes at 4 years and viral failure within 4 years.

Results Seventy-two percent of baseline immunosuppressed children recovered to normal within 4 years. Compared with “severe” immunosuppression, more children with “mild” immunosuppression (difference 36%, 95% confidence interval [CI]: 22% to 49%) or “advanced” immunosuppression (difference 20.8%, 95% CI: 5.8% to 35.9%) recovered a normal CD4%. For each 5-year increase in baseline age, the proportion of children achieving a normal CD4% declined by 19% (95% CI: 11% to 27%). Combining baseline CD4% and age effects resulted in >90% recovery when initiating HAART with “mild” immunosuppression at any age or “advanced” immunosuppression at age <3 years. Baseline CD4% effects became greater with increasing age (P = .02). At 4 years, most immunologic benefits were still significant but diminished. Viral failure was highest in infancy (56%) and adolescence (63%).

Conclusions Initiating HAART at higher CD4% and younger ages maximizes potential for immunologic recovery. Guidelines should weigh immunologic benefits against long-term risks.



Mar, 2014

HIV-1 resistance after randomized virologic switch at 1,000 or 30,000 c/ml in children.


Authors: Harrison L, Gibb DM, Fiscus S, Saïdi Y, Nastouli E, Harper L, Compagnucci A, Babiker A, Melvin A, Tudor-Williams G and the PENPACT 1 (PENTA 9/PACTG 390) Study Team.

Published in: CROI 2014, 3-6 March 2014, Boston. Poster 898.


Apr, 2011

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


Authors: The PENPACT-1 (PENTA 9 / PACTG 390) Study Team.

Published in: Lancet Infectious Diseases. April: 2011, 273-283

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.



Apr, 2010

PENTA and IMPAACT: A phase II/III randomised, open-label trial of combination antiretroviral regimens and treatment-switching strategies in HIV-1-infected antiretroviral naïve children


PENTA and IMPAACT: A phase II/III randomised, open-label trial of combination antiretroviral regimens and treatment-switching strategies in HIV-1-infected antiretroviral naïve children

Published in: XVIII International AIDS Conference, 22nd July 2010, Vienna Austria.



Jul, 2004

Choice of first-line ART regimen in PENPACT 1: a randomized trial of combination antiretroviral regimens and treatment switching strategies in antiretroviral naive children >30 days and <18 years of age.


Authors: Gibb DM, Melvin A, Compagnucci A, McKinney R, Tudor-Williams G, Walker AS, Harper L, Hodge J, Powell C, Green H, Saïdi Y, Ortiz AA, Toye M, Girard S, Mofenson L, Giaquinto C, Hughes M on behalf of the PENPACT 1 Trial.

Published in: XV International AIDS Conference, 11-16 July 2004, Bangkok. Poster TuPeB4442.