Population Pharmacokinetic Modeling of Dolutegravir to Optimize Pediatric Dosing in HIV-1-Infected Infants, Children, and Adolescents.

BACKGROUND AND OBJECTIVE: HIV treatment options remain limited in children. Dolutegravir is a potent and well-tolerated, once-daily HIV-1 integrase inhibitor recommended for HIV-1 infection in both adults and children down to 4 weeks of age. To support pediatric dosing of dolutegravir in children, we used a population pharmacokinetic model with dolutegravir data from the P1093 and ODYSSEY clinical trials. The relationship between dolutegravir exposure and selected safety endpoints was also evaluated. METHODS: A population pharmacokinetic model was developed with data from P1093 and ODYSSEY to characterize the pharmacokinetics and associated variability and to evaluate the impact of pharmacokinetic covariates. The final population pharmacokinetic model simulated exposures across weight bands, doses, and formulations that were compared with established adult reference data. Exploratory exposure-safety analyses evaluated the relationship between dolutegravir pharmacokinetic parameters and selected clinical laboratory parameters and adverse events. RESULTS: A total of N = 239 participants were included, baseline age ranged from 0.1 to 17.5 years, weight ranged from 3.9 to 91 kg, 50% were male, and 80% were black. The final population pharmacokinetic model was a one-compartment model with first-order absorption and elimination, enabling predictions of dolutegravir concentrations in the pediatric population across weight bands and doses/formulations. The predicted geometric mean trough concentration was comparable to the adult value following a 50-mg daily dose of dolutegravir for all weight bands at recommended doses. Body weight, age, and formulation were significant predictors of dolutegravir pharmacokinetics in pediatrics. Additionally, during an exploratory exposure-safety analysis, no correlation was found between dolutegravir exposure and selected safety endpoints or adverse events. CONCLUSIONS: The dolutegravir dosing in children ≥ 4 weeks of age on an age/weight-band basis provides comparable exposures to those historically observed in adults. Observed pharmacokinetic variability was higher in this pediatric population and no additional safety concerns were observed. These results support the weight-banded dosing of dolutegravir in pediatric participants currently recommended by the World Health Organization.

Association between HIV antiretroviral therapy and preterm birth based on antenatal ultrasound gestational age determination: a comparative analysis.

OBJECTIVE: To evaluate the association between HIV antiretroviral therapy (ART) and preterm birth (PTB), when defined by gold standard antenatal ultrasound versus newborn exam. DESIGN: A secondary analysis of the PROMISE 1077BF/1077FF randomized controlled trial, which compared antiretroviral strategies to reduce perinatal HIV transmission and improve maternal health. The trial used newborn exam (i.e. New Ballard Score, NBS) to assess gestational age. This analysis included liveborn singleton pregnancies with both newborn exam and ultrasound data. The primary exposure was the trial's antiretroviral strategies: zidovudine with intrapartum nevirapine ('ZDV alone'); zidovudine/lamivudine/lopinavir-ritonavir ('ZDV-based ART'); or tenofovir/emtricitabine/lopinavir-ritonavir ('TDF-based ART'). The primary outcome was PTB less than 37 and less than 34 weeks based on the gold standard of ultrasound dating. We evaluated the association between antiretroviral strategy and PTB. We fit multivariable logistic regression models, adjusting for maternal characteristics, obstetric history, and HIV disease severity. RESULTS: Among 720 assessed pregnant women, PTB less than 37 weeks was 15.4% by NBS and 18.3% by ultrasound. The NBS was specific but not sensitive for PTB less than 37 weeks (92.0% and 48.5%). Women receiving ZDV-based and TDF-based ART had significantly higher odds of PTB less than 37 by ultrasound compared with ZDV alone (adjusted odds ratios: 1.68; 95% confidence interval 1.10-2.57, and 2.71; 95% confidence interval 1.39-5.29), as well as for PTB less than 34 weeks. These results held for ultrasounds performed less than 24 weeks, and were generally consistent with prior analyses from the PROMISE trial using the NBS. CONCLUSION: Women starting HIV ART in pregnancy remained at higher risk of PTB when determined by ultrasound, consistent with prior data using newborn exam. However, newborn exam misclassified cases of PTB compared with gold standard ultrasound.

Risk Factors for Adverse Birth Outcomes in the PROMISE 1077BF/1077FF Trial.

BACKGROUND: In the multicountry PROMISE 1077BF/1077FF trial, the risk of low birth weight (LBW; <2500 g) and preterm delivery (PTD; <37 weeks) was significantly higher among women initiating a protease inhibitor-based antiretroviral treatment (ART) regimen than those receiving ZDV alone. Among those assigned to a protease inhibitor regimen, tenofovir/emtricitabine was associated with the more severe outcomes of very LBW (<1500 g) and very PTD (<34 weeks) compared with zidovudine/lamivudine. METHODS: We used multivariate logistic regression to further explore these treatment findings, taking into account demographic baseline clinical and postentry obstetrical factors. We evaluated individual adverse outcomes and composites that included stillbirth and early loss/spontaneous abortion. RESULTS: Among 3333 women delivering at least 1 live infant, median maternal age at enrollment was 26 years; 661 (20%) were primiparous, and 110 (3.3%) reported at least 1 previous PTD. Seventeen percent of newborns were LBW, 1% were very LBW, 17% had PTD, and 3% had very PTD. Treatment allocation remained strongly associated with multiple adverse outcomes after controlling for other risk factors with both ART regimens exhibiting increased risk relative to ZDV alone. Other risk factors remaining significant in at least one of the multivariate models included the following: country, gestational age at entry, maternal age, maternal body mass index, previous PTD, history of alcohol use, baseline HIV viral titer, multiple gestation, and several obstetric risk factors. CONCLUSIONS: ART effects on adverse pregnancy outcomes reported in the randomized PROMISE trial remained strongly significant even after controlling for demographic, baseline clinical, and obstetrical risk factors, which were also associated with these outcomes.

Associations of Genetically Determined Continental Ancestry With CD4+ Count and Plasma HIV-1 RNA Beyond Self-Reported Race and Ethnicity.

BACKGROUND: Ancestry informative markers (AIMs) measure genetic admixtures within an individual beyond self-reported racial/ethnic (SRR) groups. Here, we used genetically determined ancestry (GDA) across SRR groups and examine associations between GDA and HIV-1 RNA and CD4 counts in HIV-positive children in the United States. METHODS: Forty-one AIMs, developed to distinguish 7 continental regions, were detected by real-time PCR in 994 HIV-positive, antiretroviral naive children. GDA was estimated comparing each individual's genotypes to allele frequencies found in a large set of reference individuals originating from global populations using STRUCTURE. The means of GDA were calculated for each category of SRR. Linear regression was used to model GDA on CD4 count and log10 RNA, adjusting for SRR and age. RESULTS: Subjects were 61% black, 25% Hispanic, 13% white, and 1.3% Unknown. The mean age was 2.3 years (45% male), mean CD4 count of 981 cells per cubic millimeter, and mean log10 RNA of 5.11. Marked heterogeneity was found for all SRR groups with high admixture for Hispanics. In adjusted linear regression models, subjects with 100% European ancestry were estimated to have 0.33 higher log10 RNA levels (95% CI: 0.03 to 0.62, P = 0.028) and 253 CD4 cells per cubic millimeter lower (95% CI: -517 to 11, P = 0.06) in CD4 count, compared to subjects with 100% African ancestry. CONCLUSION: Marked continental admixture was found among this cohort of HIV-infected children from the United States. GDA contributed to differences in RNA and CD4 counts beyond SRR and should be considered when outcomes associated with HIV infection are likely to have a genetic component.

Genetic variants in the host restriction factor APOBEC3G are associated with HIV-1-related disease progression and central nervous system impairment in children.

BACKGROUND: Apolipoprotein B mRNA editing catalytic polypeptide 3G (APOBEC3G) protein is incorporated into nascent virus particles and mediates cytidine deamination (C-to-U) of first-strand reverse transcripts of HIV-1 in target cells resulting in G-to-A hypermutation of the coding strand and premature degradation. We investigated the effects of APOBEC3G genetic variants on HIV-1-related disease in children. METHODS: APOBEC3G variants were detected using real-time polymerase chain reaction in HIV-1-infected children from Pediatric AIDS Clinical Trials Group (PACTG) protocols P152 and P300 that evaluated the effectiveness of 3 mono- or dual-nucleoside reverse transcriptase inhibitor treatments. RESULTS: Of the 1049 children evaluated, 60% were non-Hispanic black, 26% Hispanic, 13% non-Hispanic white, and 1% other or unknown race/ethnicity. Age ranged from 42 days to 18 years; 45% were males. APOBEC3G-H186R homozygous G/G genotype was associated with more rapid HIV-1 disease progression [hazard ratio (HR): 1.69; P = 0.01] and central nervous system (CNS) impairment (HR: 2.00; P = 0.02) compared with the wild-type A/A or heterozygous A/G genotype in a recessive model. In both additive and dominant models, APOBEC3G-F119F-C allele was associated with protection against disease progression (HR [additive]: 0.69; P = 0.002 and HR [dominant]: 0.60; P = 0.001, respectively) and CNS impairment (HR [additive]: 0.65; P = 0.02 and HR [dominant]: 0.54; P = 0.007, respectively). These associations remained significant in multivariate analyses controlling for baseline characteristics or previously identified genetic variants known to alter HIV-1-related disease in this cohort of children. CONCLUSIONS: APOBEC3G-H186R and F119F variants are associated with altered HIV-1-related disease progression and CNS impairment in children.