Long-term outcomes for HIV-infected infants less than 6 months of age at initiation of lopinavir/ritonavir combination antiretroviral therapy

HIV-1 reservoir size after neonatal antiretroviral therapy and the potential to evaluate antiretroviral-therapy-free remission (IMPAACT P1115): a phase 1/2 proof-of-concept study

BACKGROUND

Infants born with HIV-1 require lifelong antiretroviral therapy (ART). We aimed to assess whether very early ART in neonates might restrict HIV-1 reservoirs, an important step towards ART-free remission.

METHODS

IMPAACT P1115 is an ongoing, phase 1/2, proof-of-concept study in which infants were enrolled at 30 research clinics in 11 countries (Brazil, Haiti, Kenya, Malawi, South Africa, Tanzania, Thailand, Uganda, the USA, Zambia, and Zimbabwe) into two cohorts. Infants at least 34 weeks' gestational age at high risk for in-utero HIV-1 with either untreated maternal HIV-1 (cohort 1) or who were receiving pre-emptive triple antiretroviral prophylaxis outside of the study (maternal ART permissible; cohort 2) were included. All infants initiated treatment within 48 h of life. Cohort 1 initiated three-drug nevirapine-based ART, and cohort 2 initiated three-drug nevirapine-based prophylaxis then three-drug nevirapine-based ART following HIV diagnosis by age 10 days. We added twice-daily coformulated oral ritonavir 75 mg/m2 and lopinavir 300 mg/m2 from 14 days of life and 42 weeks postmenstrual age. We discontinued nevirapine 12 weeks after two consecutive plasma HIV-1 RNA levels below limit of detection. We tracked virological suppression, safety outcomes, and meeting a predetermined biomarker profile at age 2 years (undetectable RNA since week 48, HIV-1 antibody-negative, HIV-1 DNA not detected, and normal CD4 count and CD4 percentage) to assess qualification for analytical treatment interruption. This study is registered with ClinicalTrials.gov, NCT02140255.

FINDINGS

Between Jan 23, 2015, and Dec 14, 2017, 440 infants were included in cohort 1 and 20 were included in cohort 2. 54 of these infants (34 from cohort 1 and 20 from cohort 2) had confirmed in-utero HIV-1 and were enrolled to receive study ART. 33 (61%) of 54 infants were female and 21 (39%) were male. The estimated probability of maintaining undetectable plasma RNA through to 2 years was 33% (95% CI 17-49) in cohort 1 and 57% (28-78) in cohort 2. Among infants maintaining protocol-defined virological control criteria through to study week 108, seven of 11 (64%, 95% CI 31-89) in cohort 1 and five of seven (71%, 29-96) in cohort 2 had no detected HIV-1 DNA. Ten of 12 (83%, 52-100) in cohort 1 and all seven (100%, 59-100) in cohort 2 tested HIV-1 antibody-negative at week 108. Among 54 infants initiated on very early ART, ten (19%; six in cohort 1 and four in cohort 2) met all criteria for possible analytical treatment interruption. Reversible grade 3 or 4 adverse events occurred in 15 (44%) of 34 infants in cohort 1 and seven (35%) of 20 infants in cohort 2.

INTERPRETATION

Very early ART for in-utero HIV-1 can achieve sustained virological suppression in association with biomarkers indicating restricted HIV-1 reservoirs by age 2 years, which might enable potential ART-free remission.

FUNDING

National Institute of Allergy and Infectious Diseases, the Eunice Kennedy Shriver National Institute of Child Health and Human Development, and the National Institute of Mental Health.

Thirteen-year viral suppression and immunologic recovery of LPV/r-based regimens in pediatric HIV treatment: a multicenter cohort study in resource-constrained settings of China

Background

Antiretroviral Therapy (ART) in children remains challenging due to resource-constrained settings. We conducted a 13-year, prospective, multicenter cohort study on the effectiveness and safety of LPV/r-based regimens in ART-naive and ART-experienced children.

Methods

From January 2008 to May 2021, children living with HIV-1 were recruited with LPV/r-based regimens from 8 clinical research sites in 6 provinces in China. Effectiveness outcomes were virologic failure (defined as at least two consecutive measurements of VL > 200 copies/mL after 6 months of ART) and immune response (defined as CD4% recovered to more than 25% after 12 months of treatment). The safety outcomes were treatment-related grade 2-4 adverse events and abnormal laboratory test results.

Results

A total of 345 ART-naïve children and 113 ART-experienced children were included in this cohort study. The median follow-up time was 7.3 (IQR 5.5-10.5) years. The incidence density of virologic failure was 4.1 (95% CI 3.3-4.9) per 100 person-years in ART-naïve children and 5.0 (95% CI 3.5-6.5) per 100 person-years in ART-experienced children. Kaplan Meyer (KM) curve analysis showed children with ART experience were at a higher risk of virologic failure (p < 0.05). The risk factors of virologic failure in ART-naïve children were clinic setting in rural hospitals (aHR = 2.251, 1.108-4.575), annual missed dose times >5 days of LPV intake (aHR = 1.889, 1.004-3.554); The risk factor of virologic failure in ART-experienced children was missed dose times >5 days (aHR = 2.689, 1.299-5.604) and mother as caregivers for ART administration (aHR = 0.475, 0.238-0.948). However, during long-term treatment, viral suppression rates between ART-naïve and ART-experienced children remained similar. No significant differences were observed in the immune response, treatment-related grade 2-4 events, and abnormal laboratory test results between ART-naïve children and ART-experienced children.

Conclusion

Our research underscores that with consistent, long-term treatment of LPV/r-based regimens, ART-experienced children can achieve therapeutic outcomes comparable to ART-naïve children. It provides crucial insights on LPV/r-based regimens in pediatric HIV treatment, especially in resource-limited settings where high-cost Integrase Strand Transfer Inhibitors (INSTs) are inaccessible. This evidence-based understanding provides an essential addition to the global therapeutic strategies for pediatric HIV treatment.

Population Pharmacokinetics of Lopinavir/Ritonavir: Changes Across Formulations and Human Development From Infancy Through Adulthood

Lopinavir/ritonavir (LPV/r) is recommended by the World Health Organization as first-line treatment for HIV-infected infants and young children. We performed a composite population pharmacokinetic (PK) analysis on LPV plasma concentration data from 6 pediatric and adult studies to determine maturation and formulation effects from infancy to adulthood. Intensive PK data were available for infants, children, adolescents, and adults (297 intensive profiles/1662 LPV concentrations). LPV PK data included 1 adult, 1 combined pediatric-adult, and 4 pediatric studies (age 6 weeks to 63 years) with 3 formulations (gel-capsule, liquid, melt-extrusion tablets). LPV concentrations were modeled using nonlinear mixed effects modeling (NONMEM v. 7.3; GloboMax, Hanover, Maryland) with a one compartment semiphysiologic model. LPV clearance was described by hepatic plasma flow (QHP ) times hepatic extraction (EH ), with EH estimated from the PK data. Volume was scaled by linear weight (WT/70)1.0 . Bioavailability was assessed separately as a function of hepatic extraction and the fraction absorbed from the gastrointestinal tract. The absorption component of bioavailability increased with age and tablet formulation. Monte Carlo simulations of the final model using current World Health Organization weight-band dosing recommendations demonstrated that participants younger than 6 months of age had a lower area under the drug concentration-time curve (94.8 vs >107.4 μg hr/mL) and minimum observed concentration of drug in blood plasma (5.0 vs > 7.1 μg/mL) values compared to older children and adults. Although World Health Organization dosing recommendations include a larger dosage (mg/m2 ) in infants to account for higher apparent clearance, they still result in low LPV concentrations in many infants younger than 6 months of age receiving the liquid formulation.

Dose-dependent neurocognitive deficits following postnatal day 10 HIV-1 viral protein exposure: Relationship to hippocampal anatomy parameters

Despite the availability of antiretroviral prophylactic treatment, pediatric human immunodeficiency virus type 1 (HIV-1) continues to be a significant risk factor in the post-cART era. The time of infection (i.e., during pregnancy, delivery or breastfeeding) may play a role in the development of neurocognitive deficits in pediatric HIV-1. HIV-1 viral protein exposure on postnatal day (P)1, preceding the postnatal brain growth spurt in rats, had deleterious effects on neurocognitive development and anatomical parameters of the hippocampus (Fitting et al., 2008a,b). In the present study, rats were stereotaxically injected with HIV-1 viral proteins, including Tat1-86 and gp120, on P10 to further examine the role of timing on neurocognitive development and anatomical parameters of the hippocampus (Fitting et al., 2010). The dose-dependent virotoxin effects observed across development following P10 Tat1-86 exposure were specific to spatial learning and absent from prepulse inhibition and locomotor activity. A relationship between alterations in spatial learning and/or memory and hippocampal anatomical parameters was noted. Specifically, the estimated number of neurons and astrocytes in the hilus of the dentate gyrus explained 70% of the variance of search behavior in Morris water maze acquisition training for adolescents and 65% of the variance for adults; a brain-behavior relationship consistent with observations following P1 viral protein exposure. Collectively, late viral protein exposure (P10) results in selective alterations in neurocognitive development without modifying measures of somatic growth, preattentive processing, or locomotor activity, as characterized by early viral protein exposure (P1). Thus, timing may be a critical factor in disease progression, with children infected with HIV earlier in life being more vulnerable to CNS disease.

A Phase II/III Trial of Lopinavir/Ritonavir Dosed According to the WHO Pediatric Weight Band Dosing Guidelines

BACKGROUND

The World Health Organization (WHO) recommends weight band dosing of antiretrovirals for children. Data are limited describing drug exposure/safety of lopinavir/ritonavir using WHO weight band dosing.

METHODS

International Maternal Pediatric Adolescent AIDS Clinical Trials (IMPAACT) P1083 was a phase II/III trial assessing the pharmacokinetics (PK) and short-term safety, tolerance and efficacy of lopinavir/ritonavir in human immunodeficiency virus-infected children 3-25 kg dosed according to WHO weight bands, with liquid solution or meltrex extrusion tablets. The main PK target was an area under the curve (AUC0-24) of 80-320 μg·h/mL.

RESULTS

Of 97 enrolled participants, median age 2.5 years, 89 (91.8%) completed the protocol. Median LPV dose was 303 mg/m. The geometric mean (90% confidence limits) LPV PK AUC0-24 was 196 (177-217) μg·h/mL and Cmin was 2.47 (1.52-4.02) μg/mL. AUC0-24 was within the target range for 79% of participants. The median (Q1, Q3) difference between individual observed PK parameters and those expected if Food and Drug Administration dosing guidelines were followed was 30.7 (7.9, 54.3) for AUC0-24 and 0.56 (0, 1.27) for Cmin. Ten (10%) participants had grade 3 or 4 events deemed related to study treatment, mostly asymptomatic laboratory abnormalities. Three participants died of unrelated study treatment causes. At week 24, 57 of 79 (72%) participants reached viral suppression and the median increase in CD4% (n = 83) was 6.0 (P < 0.0001).

CONCLUSIONS

WHO weight band dosing guidelines in children achieved adequate LPV plasma exposure but was higher than that expected with Food and Drug Administration dosing guidelines. Despite the higher LPV exposure, the treatment was well tolerated and the 24-week efficacy data were favorable.

Moving forward with treatment options for HIV-infected children

INTRODUCTION

Current international guidelines recommend to treat all HIV-1 infected patients regardless of CD4 cell count. Despite the remarkable worldwide progress for universal access to antiretroviral during the last decade, the pediatric population remains fragile due to lack of randomized studies, inappropriate antiretroviral formulations, adherence difficulties, drug toxicity and development of resistance.

AREAS COVERED

This review summarizes the latest recommendations and advances for the treatment of HIV-infected children and highlights the potential complications of a lifelong antiretroviral treatment initiated early in life.

EXPERT OPINION

International guidelines recommend to start combination antiretroviral therapy (cART) as fast as possible in all children diagnosed with HIV-1. The principal goal is to improve survival and reduce mortality as well as rapidly decrease HIV reservoirs. This remains a challenge in resource-limited settings were diagnostic tools and treatment access may be limited. Different new strategies are in the pipeline such as immunotherapy in combination with very early cART initiation to seek remission or functional cure. For the time being and awaiting for long term remission or cure, there is a need for further pharmacokinetics studies, more pediatric formulations with improved palatability and implementation of randomized trials for the newer antiretroviral drugs.

Impact of lopinavir-ritonavir exposure in HIV-1 infected children and adolescents in Madrid, Spain during 2000-2014

Background

The most-used protease-inhibitor in children is Lopinavir-ritonavir (LPV/r), which provides durable suppression of viral load and increases CD4+T-counts. This study describes the virological outcome of the HIV-1-infected paediatric population exposed to LPV/r during 15 years in Spain.

Methodology

Patients from the Madrid Cohort of HIV-1-infected-children and adolescents exposed to LPV/r as different line therapy during 2000–2014 were selected. The baseline epidemiological-clinical features, viral suppression, changes in CD4+T-CD8+T cell counts and drug susceptibility were recorded before and during LPV/r exposure. Drug resistance mutations (DRM) were identified in viruses from samples collected until 2011. We predicted drug susceptibility to 19 antiretrovirals among those carrying DRM using the Stanford′s HIVdb Algorithm.

Results

A total of 199 (37.3%) of the 534 patients from the cohort were exposed to LPV/r during 2000–2014 in first (group 1), second (group 2) or more line-therapies (group 3). Patients were mainly Spaniards (81.9%), perinatally infected (96.5%) with subtype-B (65.3%) and HIV-diagnosed before year 2000 (67.8%). The mean age at first LPV/r exposure was 9.7 years. After protease-inhibitor exposure, viral suppression was higher in groups 1 and 2 than in group 3. Viral suppression occurred in 87.5%, 68.6% and 64.8% patients from groups 1, 2 and 3, respectively. Among the 64 patients with available resistance data during LPV/r treatment, 27(42.3%) carried DRM to protease-inhibitor, 28 (58.3%) to reverse-transcriptase-inhibitors and 21 (43.7%) to non-reverse-transcriptase-inhibitors. Darunavir/ritonavir, atazanavir-ritonavir and tipranavir/ritonavir presented the highest susceptibility and nelfinavir the lowest.

Conclusions

A better lymphocyte recovering occurred when protease-inhibitor was taken as part of a first-line regimen and a higher number of patients reached viral suppression. The least compromised antiretrovirals for rescue antiretroviral regimens, according to DRM in the LPV/r-exposed-paediatric cohort, were mainly the new protease inhibitors.

Early age at start of antiretroviral therapy associated with better virologic control after initial suppression in HIV-infected infants

OBJECTIVE

The report of the 'Mississippi baby' who was initiated on antiretroviral therapy (ART) within 30 h of birth and maintained viral suppression off ART for 27 months has increased interest in the timing of ART initiation early in life. We examined associations between age at ART initiation and virologic outcomes in five cohorts of HIV-infected infants and young children who initiated ART before 2 years of age in Johannesburg, South Africa.

METHODS

We compared those who initiated ART early (<6 months of age) and those who started ART late (6-24 months of age). Two primary outcomes were examined: initial response to ART in three cohorts and later sustained virologic control after achieving suppression on ART in two cohorts.

RESULTS

We did not observe consistent differences in initial viral suppression rates by age at ART initiation. Overall, initial viral suppression rates were low. Only 31, 40.1, and 26.5% of early-treated infants (<6 months of age) in the three cohorts, respectively, were suppressed less than 50 copies/ml of HIV RNA 6 months after starting ART. We did observe better sustained virologic control after achieving suppression on ART among infants starting ART early compared with late. Children who started ART early were less likely to experience viral rebound (>50 copies/ml or >1000 copies/ml) than children who started late in both cohorts.

CONCLUSION

These findings provide additional support for early initiation of ART in HIV-infected infants.

Early Combination Antiretroviral Therapy Limits HIV-1 Persistence in Children

Globally, 240,000 infants are newly infected with HIV-1 each year and 3.2 million children are living with the infection. Combination antiretroviral therapy (cART) has reduced HIV-1-related disease and mortality in children but is not curative owing to the early generation of a latent reservoir of long-lived memory CD4(+) T cells bearing replication-competent HIV-1 provirus integrated into cellular DNA. This review focuses on recent advances in our understanding of the establishment of HIV-1 persistence in children and how early initiation of cART in the setting of the developing infant immune system limits the formation of the long-lived latent CD4(+) cell reservoir that remains a barrier to remission or cure.

Growth reconstitution following antiretroviral therapy and nutritional supplementation: systematic review and meta-analysis

OBJECTIVE

As antiretroviral therapy (ART) expands for HIV-infected children, it is important to determine its impact on growth. We quantified growth and its determinants following ART in resource-limited (RLS) and developed settings.

DESIGN

Systematic review and meta-analysis.

METHODS

We searched publications reporting growth [weight-for-age (WAZ), height-for-age (HAZ), and weight-for-height (WHZ) z scores] in HIV-infected children following ART through August 2014. Inclusion criteria were as follows: younger than 18 years; ART; at least 20 patients; growth at ART; and post-ART growth. Standardized and overall weighted mean differences were calculated using random-effects models.

RESULTS

A total of 67 articles were eligible (RLS = 54; developed settings = 13). Mean age was 5.8 years, and comparable between settings (P = 0.90). Baseline growth was substantially lower in RLS vs. developed settings (WAZ -2.1 vs. -0.5; HAZ -2.2 vs. -0.9; both P < 0.01). Rate of weight but not height reconstitution during 12 and 24 months was higher in RLS (12-month WAZ change 0.84 vs. 0.17, P < 0.01). Growth deficits persisted in RLS after 2 years ART (P = 0.04). Younger cohort age was associated with greater growth reconstitution. Protease inhibitor and nonnucleoside reverse-transcriptase inhibitor regimens yielded comparable growth. Adjusting for age and setting, cohorts with nutritional supplements had greater growth gains (24-month rate difference: WAZ 0.55, P = 0.03; HAZ 0.60, P = 0.007). Supplement benefits were attenuated after adjusting for baseline cohort growth.

CONCLUSION

RLS children had substantial growth deficits compared with developed settings counterparts at ART; growth shortfalls in RLS persisted despite reconstitution. Earlier age and nutritional supplementation at ART may improve growth outcomes. Scant data on supplementation limit evaluation of impact and underscores need for systematic data collection regarding supplementation in pediatric ART programmes/cohorts.

Cell-Associated HIV-1 DNA and RNA Decay Dynamics During Early Combination Antiretroviral Therapy in HIV-1-Infected Infants

BACKGROUND

The decay of human immunodeficiency virus type 1 (HIV-1)-infected cells during early combination antiretroviral therapy (cART) in infected infants is not defined.

METHODS

HIV-1 DNA, including 2-long terminal repeat (2-LTR) circles, and multiply spliced (ms-) and unspliced (us-) HIV-1 RNA concentrations were measured at 0, 24, 48, and 96 weeks of cART in infants from the IMPAACT P1030 trial receiving lopinavir-ritonavir-based cART. The ratio of HIV-1 DNA concentrations to replication-competent genomes was also estimated. Linear mixed effects models with random intercept and linear splines were used to estimate patient-specific decay kinetics of HIV-1 DNA.

RESULTS

The median HIV-1 DNA concentration before cART at a median age of 2 months was 3.2 log10 copies per million PBMC. With cART, the average estimated patient-specific change in HIV-1 DNA concentrations was -0.040 log10/week (95% confidence interval [CI], -.05, -.03) between 0 and 24 weeks and -0.017 log10/week between 24 and 48 weeks (95% CI, -.024, -.01). 2-LTR circles decreased with cART but remained detectable through 96 weeks. Pre-cART HIV-1 DNA concentration was correlated with time to undetectable plasma viral load and post-cART HIV-1 DNA at 96 weeks; although HIV-1 DNA concentrations exceeded replication-competent HIV-1 genomes by 148-fold. Almost all infants had ms- and usRNA detected pre-cART, with 75% having usRNA through 96 weeks of cART.

CONCLUSIONS

By 2 months of age, a large pool of HIV-1-infected cells is established in perinatal infection, which influences time to undetectable viral load and reservoir size. This has implications for informing novel approaches aimed at early restriction of HIV-1 reservoirs to enable virologic remission and cure.

Antiretroviral therapy during the neonatal period

No abstract available

Efficacy and safety of tipranavir coadministered with ritonavir in HIV-1-infected children and adolescents: 5 years of experience

BACKGROUND

To evaluate the long-term (up to week 292) safety, efficacy and tolerability of ritonavir-boosted tipranavir in HIV-1-infected pediatric patients. Long-term follow up of patients enrolled in the randomized, open-label pediatric trial (1182.14/PACTG1051).

METHODS

HIV-1-infected pediatric patients (2-18 years) who participated in the PACTG 1051 trial were followed for ritonavir-boosted tipranavir-based regimen efficacy, safety and tolerability through week 292.

RESULTS

In patients <12 years of age, 51/62 (82%) were receiving drug at week 48 and 13/62 (21%) at week 288. Among adolescents (12-18 years of age), 35/53 (66%) were receiving drug at week 48 and 2/53 (4%) at week 288. Among patients 2 to <6 years of age, 18/25 (72%) had viral loads <400 copies/mL at week 48. By week 292, 9/25 (36%) of patients had viral loads <400 copies/mL. Among older patients, week 48 responder rates were 35% (13/37 of patients 6 to <12 years of age) and 32% (17/53 of patients 12 to 18 years of age). By week 292, 6/37 (16%) of those 6 to <12 years of age and 2/53 (4%) of those 12 to 18 years of age had viral loads <400 copies/mL. Overall safety and tolerability profiles were best for children who initiated treatment between 2 and <6 years of age. Drug-related adverse events (investigator defined) were similar across all age groups (55-65%).

CONCLUSIONS

Pediatric patients who begin treatment at the earlier ages, and who are stable on a ritonavir-boosted tipranavir-based regimen at week 48, generally continue to demonstrate good safety, tolerability and virologic efficacy profiles up to 292 weeks of treatment.

Pharmacokinetics, safety and antiviral activity of fosamprenavir/ritonavir-containing regimens in HIV-infected children aged 4 weeks to 2 years-48-week study data

BACKGROUND

Pharmacokinetics, safety and antiviral activity of fosamprenavir (FPV) with ritonavir (RTV) twice daily were evaluated in HIV-1-infected infants and children 4 weeks to <2 years over 48 weeks.

METHODS

Results from intensive pharmacokinetic sampling of subjects enrolled in single dose visits was used to determine individualized dosing for the first 6-10 subjects in each of 2 cohorts (4 weeks to <6 months, 6 months to <2 years); steady state pharmacokinetic data were then used to select the dosage regimen for the remaining subjects recruited to the cohort. Intensive pharmacokinetic sampling was performed at week 2 or 8; predose samples were collected every 4-12 weeks thereafter. Safety and plasma HIV-1 RNA were monitored every 4-12 weeks.

RESULTS

Fifty-nine subjects received study medication. FPV 45 mg/kg boosted with RTV 7 to 10 mg/kg BID achieved average plasma amprenavir area under curve(0-τ) values 26% to 28% lower and Cmax similar to historical adult data for FPV/RTV 700/100 mg BID; amprenavir Cτ values were lower in the subjects <6 months of age. At week 48, 35 of 54 (65%) subjects had achieved plasma HIV-1 RNA <400 copies/mL and 33 of 54 (61%) had plasma HIV-1 RNA values <50 copies/mL. The most common adverse events were diarrhea, upper respiratory tract infection, gastroenteritis and otitis media.

CONCLUSIONS

Final FPV/RTV dosing regimens achieved plasma amprenavir exposures comparable with those from regimens approved in adults, with the exception of trough exposures in the <6-month-old infants. The FPV/RTV regimens led to viral suppression in 61% of patients and were generally well tolerated.

Mortality and long-term virologic outcomes in children and infants treated with lopinavir/ritonavir

BACKGROUND

There is scant data on young children receiving protease inhibitor-based therapy in real-life resource-limited settings and on the optimal timing of therapy among children who survive infancy. Our aim was to evaluate outcomes at the Hospital del Niño, Panama, where children have been routinely treated with lopinavir/ritonavir (LPV/r)-based therapy since 2002.

METHODS

Retrospective cohort analysis of all HIV-infected children enrolled in care between January 1, 1991, and June 1, 2011. Kaplan-Meier method and Cox proportional hazards regression were used to evaluate death, virologic suppression and virologic rebound.

RESULTS

Of 399 children contributing 1944 person-years of follow-up, 254 (63.7%) were treated with LPV/r and 94 (23.6%) were never treated with antiretrovirals (ARVs). Among infants, improved survival was associated with male gender (hazard rate of death[HRdeath] 0.54, 95% confidence interval [CI]: 0.32-0.92) and treatment with highly active antiretroviral therapy (HRdeath 0.32, 95% CI: 0.12-0.83), whereas residence outside of Panama City was associated with poorer survival (HRdeath 1.72, 95% CI: 1.01-2.94). Among children who survived to 1 year of age without exposure to ARVs, LPV/r-based therapy improved survival (HRdeath 0.07, 95% CI: 0.01-0.33). Virologic suppression was achieved in 42.1%, 70.5% and 85.1% by 12, 24 and 60 months of follow-up among children treated with LPV/r. Virologic suppression was not associated with prior ARV exposure or age at initiation of therapy but was associated with residence outside of Panama City (HR suppression 1.93, 95% CI: 1.19-3.14). Patients with a baseline viral load >100,000 copies/mL were less likely to achieve suppression (HR suppression 0.37, 95% CI: 0.21-0.66). No children who achieved virologic suppression after initiating LPV/r died.

CONCLUSIONS

LPV/r-based therapy improved survival not only in infants but also in children over 1 year of age. Age at initiation of LPV/r-based therapy or prior ARVs did not impact virologic outcomes.

Pharmacotherapy of pediatric HIV infection

The delivery of safe and effective antiretroviral therapy to children and adolescents is crucial to save the lives of millions of children worldwide. The immunologic response to human immunodeficiency infection is closely related to a child's development and creates age-specific parameters for the evaluation of therapeutic response to antiretroviral therapy. Similarly, the development and maturation of organ systems involved in drug absorption, distribution, metabolism, and elimination determines significant changes in the pharmacokinetics of antiretroviral drugs throughout childhood. The authors review the evolution in treatment of pediatric HIV from infancy through adolescence.

The glory of guidelines and the twilight of reality: controversies and challenges in the prevention and treatment of HIV in children

Since the discovery of HIV 30 years ago, we have learned much about HIV in children and adolescents. Dramatic declines have occurred in mother-to-child transmission of HIV in resource-rich countries. Resource-poor countries struggle with improving prevention of mother-to-child transmission due to the lack of universal antiretroviral treatment for pregnant and nursing mothers. In children infected with HIV, pharmacokinetic, safety and efficacy data have been determined for many of the older drugs. Data are lacking for the newer, safer and more effective currently available drugs, resulting in the pediatric guidelines lagging behind adult recommendations. Although guidelines for prevention and treatment are helpful, the way they are created causes them to lag behind new scientific evidence, and in some situations they will be confusing or only based on expert opinion. Improving prevention of HIV infection in adolescents and young adults and in treating those who become HIV infected is crucially important. The next 10 years hold tremendous opportunities for improvements in prevention and treatment of HIV in children, adolescents and young adults.

Trough lopinavir concentrations in preterm HIV-infected infants

Because of serious adverse effects, the Food and Drug Administration warns against using lopinavir in infants younger than 42 weeks postconception. However, there is an imperative for early treatment. We report on our use of LPV in 8 premature HIV-infected infants. The median age at initiation was 27 days. Trough values guided dosing. Five infants needed doses above 300 mg/m. Although no adverse events were noted, lopinavir usage requires caution and careful monitoring.

Novel use of surveillance data to detect HIV-infected persons with sustained high viral load and durable virologic suppression in New York City

BACKGROUND

Monitoring of the uptake and efficacy of ART in a population often relies on cross-sectional data, providing limited information that could be used to design specific targeted intervention programs. Using repeated measures of viral load (VL) surveillance data, we aimed to estimate and characterize the proportion of persons living with HIV/AIDS (PLWHA) in New York City (NYC) with sustained high VL (SHVL) and durably suppressed VL (DSVL).

METHODS/PRINCIPAL FINDINGS

Retrospective cohort study of all persons reported to the NYC HIV Surveillance Registry who were alive and ≥12 years old by the end of 2005 and who had ≥2 VL tests in 2006 and 2007. SHVL and DSVL were defined as PLWHA with 2 consecutive VLs ≥100,000 copies/mL and PLWHA with all VLs ≤400 copies/mL, respectively. Logistic regression models using generalized estimating equations were used to model the association between SHVL and covariates. There were 56,836 PLWHA, of whom 7% had SHVL and 38% had DSVL. Compared to those without SHVL, persons with SHVL were more likely to be younger, black and have injection drug use (IDU) risk. PLWHA with SHVL were more likely to die by 2007 and be younger by nearly ten years, on average.

CONCLUSIONS/SIGNIFICANCE

Nearly 60% of PLWHA in 2005 had multiple VLs, of whom almost 40% had DSVL, suggesting successful ART uptake. A small proportion had SHVL, representing groups known to have suboptimal engagement in care. This group should be targeted for additional outreach to reduce morbidity and secondary transmission. Measures based on longitudinal analyses of surveillance data in conjunction with cross-sectional measures such as community viral load represent more precise and powerful tools for monitoring ART effectiveness and potential impact on disease transmission than cross-sectional measures alone.

Assessment of lopinavir pharmacokinetics with respect to developmental changes in infants and the impact on weight band-based dosing

Improved antiretroviral therapies are needed for the treatment of HIV-infected infants, given the rapid progression of the disease and drug resistance resulting from perinatal exposure to antiretrovirals. We examined longitudinal pharmacokinetics (PK) data from a clinical trial of lopinavir/ritonavir (LPV/r) in HIV-infected infants in whom therapy was initiated at less than 6 months of age. A population PK analysis was performed using NONMEM to characterize changes in lopinavir (LPV) PK relating to maturational changes in infants, and to assess dosing requirements in this population. We also investigated the relationship between LPV PK and viral dynamic response. Age and ritonavir concentrations were the only covariates found to be significant. Population PK of LPV was characterized by high apparent clearance (CL/F) in young infants, which decreased with increasing age. Although younger infants had lower LPV concentrations, the viral dynamics did not correlate with initial LPV exposure. Monte Carlo simulations demonstrated that WHO weight band-based dosing recommendations predicted therapeutic LPV concentrations and provided drug exposure levels comparable to those resulting from US Food and Drug Administration (FDA)-suggested dosing regimens.