Emergence of Resistance in HIV-1 Integrase with Dolutegravir Treatment in a Pediatric Population from the IMPAACT P1093 Study.

P1093 is a multicenter, open-label, phase I/II study of pharmacokinetics, safety, and tolerability of dolutegravir plus an optimized background regimen in pediatric participants aged 4 weeks to <18 years with HIV-1. Most participants were highly treatment experienced. We report the mechanisms of emergent integrase strand transfer inhibitor (INSTI) resistance among adolescents and children receiving dolutegravir. Plasma was collected at screening and near protocol-defined virologic failure (PDVF) for population-level and, for some samples, clonal-level integrase genotyping, phenotyping, and replication capacity. HIV-1 RNA was assessed in all available plasma samples. Phylogenetic analysis of clonal integrase sequences and homology modeling of HIV-1 intasome complexes containing resistance-associated substitutions were performed. Treatment-emergent INSTI resistance was detected in 8 participants who met PDVF criteria. The rare INSTI resistance-associated substitution G118R or R263K developed in 6 participants. The on-study secondary integrase substitution E157Q or L74I was observed in 2 participants. G118R reduced dolutegravir susceptibility and integrase replication capacity more than R263K and demonstrated greater reduction in susceptibility and integrase replication capacity when present with specific secondary integrase substitutions, including L74M, T66I, and E138E/K. Continuing evolution after R263K acquisition led to reduced dolutegravir susceptibility and integrase replication capacity. Structural examination revealed potential mechanisms for G118R- and R263K-mediated INSTI resistance. G118R and R263K INSTI resistance substitutions, which are distinct to second-generation INSTIs, were detected in adolescents and children with prior virologic failure who received dolutegravir. This study provides additional molecular and structural characterization of integrase to aid in the understanding of INSTI resistance mechanisms in antiretroviral-experienced populations. (This study has been registered at ClinicalTrials.gov under identifier NCT01302847.).

Lack of effect of oral cabotegravir on the pharmacokinetics of a levonorgestrel/ethinyl oestradiol-containing oral contraceptive in healthy adult women.

AIMS: This study aimed to investigate whether cabotegravir (CAB), an integrase inhibitor in development for treatment and prevention of human immunodeficiency virus-1, influences the pharmacokinetics (PK) of a levonorgestrel (LNG) and ethinyl oestradiol (EO)-containing oral contraceptive (OC) in healthy women. METHODS: In this open-label, fixed-sequence crossover study, healthy female subjects received LNG 0.15 mg/EO 0.03 mg tablet once daily Days 1-10 alone and with oral CAB 30 mg once daily Days 11-21. At the end of each treatment period, subjects underwent predose sampling for concentrations of follicle-stimulating hormone, luteinizing hormone, and progesterone and serial PK sampling for plasma LNG, EO, and CAB concentrations. RESULTS: Twenty women were enrolled, and 19 completed the study. One subject was withdrawn due to an adverse event unrelated to study medications. Geometric least squares mean ratios (90% confidence interval) of LNG + CAB vs. LNG alone for LNG area under the plasma concentration-time curve over the dosing interval of duration τ and maximum observed plasma concentration were 1.12 (1.07-1.18) and 1.05 (0.96-1.15), respectively. Geometric least squares mean ratio (90% confidence interval) of EO + CAB vs. EO alone for EO area under the plasma concentration-time curve over the dosing interval of duration τ and maximum observed plasma concentration were 1.02 (0.97-1.08) and 0.92 (0.83-1.03), respectively. Steady-state CAB PK parameters were comparable to historical values. There was no apparent difference in mean luteinizing hormone, follicle-stimulating hormone, and progesterone concentrations between periods. No clinically significant trends in laboratory values, vital signs, or electrocardiography values were observed. CONCLUSIONS: Repeat doses of oral CAB had no significant effect on LNG/EO PK or pharmacodynamics, which supports CAB coadministration with LNG/EO OCs in clinical practice.

No clinically significant pharmacokinetic interactions between dolutegravir and daclatasvir in healthy adult subjects.

BACKGROUND: Daclatasvir (DCV) is an NS5A replication complex inhibitor recently approved for chronic hepatitis C virus treatment. METHODS: To assess drug interactions between the HIV integrase strand transfer inhibitor dolutegravir (DTG) and DCV, subjects were randomized into 1 of 2 sequences in an open-label, 3-period, crossover study. Subjects received either DTG 50 mg once daily or DCV 60 mg once daily for 5 days in periods 1 and 2 and DTG 50 mg plus DCV 60 mg once daily for 5 days in period 3, with no washout between periods 2 and 3. Between periods 1 and 2, there was a washout period of at least 7 days. RESULTS: The geometric least-squares mean ratios (90 % confidence intervals) of DCV area under the concentration-time curve over a dosing interval (AUC0-τ), maximum observed concentration (Cmax), and concentration at the end of the dosing interval (Cτ) were 0.978 (0.831-1.15), 1.03 (0.843-1.25), and 1.06 (0.876-1.29), respectively, when DCV was administered with DTG compared with DCV alone. Compared with DTG alone, coadministration of DTG with DCV increased DTG AUC0-τ, Cmax, and Cτ by approximately 33, 29, and 45 %, respectively. CONCLUSIONS: DCV plasma exposure was not meaningfully affected by DTG. Coadministration of DTG with DCV resulted in slight increases in DTG AUC0-τ, Cmax, and Cτ. Accumulated safety and tolerability data in humans receiving DTG to date suggests this effect is not considered clinically significant. DTG and DCV can be coadministered without dose adjustment. TRIAL REGISTRATION: Registered on March 6, 2014 with ClinicalTrials.gov; registration number: NCT02082808 and as Study ID: 201102 on the ViiV Clinical Study Registry.

Establishment of biochemistry reference values for healthy Tanzanian infants, children and adolescents in Kilimanjaro Region.

OBJECTIVE: To establish common biochemistry reference intervals for Tanzanian infants, children and adolescents living in the Kilimanjaro Region. METHODS: We recruited healthy, HIV-uninfected Tanzanian infants, children and youth between the ages of 1 month and 17 years from local schools and clinics to participate in this study. Only afebrile children without signs of physical or chronic illness were enrolled. Nonparametric methods were used to determine 95% reference limits and their 90% confidence intervals, with outliers removed by the Tukey method. RESULTS: A total of 619 healthy infants, children and adolescents were enrolled into the study. Twenty-three biochemistry parameters were measured. Compared to US reference intervals, several of the biochemistry parameters showed notable differences, namely alkaline phosphatase, phosphorus, amylase and lipase. Comparing our data to the US National Institutes of Health (NIH) Division of AIDS (DAIDS) grading criteria for classification of adverse events, we found that for selected parameters, up to 15% of infants or children in certain age groups would have been categorised as having an adverse event as defined by DAIDS. CONCLUSIONS: Our study further confirms the need to use locally established reference intervals to define reference laboratory parameters among children in Africa, rather than relying on those derived from US or European populations. To our knowledge, this study provides the first set of locally validated biochemistry reference ranges for a paediatric population in Tanzania.

Advancing research and development of anti-infectives for children with a focus on antiretroviral therapy: A clinical development perspective.

The HIV treatment landscape for adults has progressed dramatically in recent decades; however, paediatric populations continue to experience delayed and limited access to effective and safe antiretroviral therapy options. Despite current incentive programmes, formulation research and development and approved drug dosing for children have been limited, particularly for neonates (aged <4 wk). Regulatory approval of drug formulations and dosing in children may lag behind adult approvals by years. Formulation and trial design adjustments complicate paediatric drug development, all of which are vital to accommodate for physiological differences, organ maturation, and rapid weight gain, which are most significant in the youngest children. To facilitate more rapid anti-infective drug development for paediatric populations, regulatory agencies provide guidelines that include extrapolating efficacy and safety data from relevant populations; using pharmacokinetic (PK) bridging and modelling to reduce sample sizes and limit the number of PK studies needed before efficacy analyses; and enrolling age- or weight-based cohorts in parallel rather than sequentially for clinical trials. Ensuring access to approved drugs poses an additional challenge, as uncertainty in demand leads to manufacturing and supply complexity with potentially higher costs that can be a barrier to uptake. Here we summarise challenges in drug development for children living with HIV, which are not unique to antiretrovirals. We aim to propose strategies for how model-based approaches and global partnerships can overcome some of these barriers to accelerate paediatric drug development, with particular reference to HIV, and how lessons learnt from HIV could be extended to other anti-infectives.

A Model-Based Approach Supporting Abacavir/Dolutegravir/Lamivudine Fixed-Dose Combination Approval in Children Living with HIV-1.

In March 2022, the US Food and Drug Administration expanded indications of TRIUMEQ, a once-daily fixed-dose combination (FDC) containing abacavir (ABC), dolutegravir (DTG), and lamivudine (3TC) to include pediatric patients weighing at least 10 kg for the treatment of HIV-1. Prior to this extension, the ABC 600 mg/DTG 50 mg/3TC 300 mg FDC tablet was approved for use only in the adult/adolescent population, weighing ≥40 kg while each component of the FDC was approved for its use in pediatric patients at least 3 months and older. A new child-friendly formulation was developed as an FDC dispersible tablet (DT) of ABC 60 mg/DTG 5 mg/3TC 30 mg for pediatric patients with a body weight ≥ 6 kg. The present work demonstrates the utility of applying a model-informed drug development (MIDD) approach to expedite ABC/DTG/3TC FDC approval for pediatric patients (≥10 to <40 kg) based on data from the existing individual components and formulation bridging. Population pharmacokinetic models developed for pediatric participants across all three components of ABC/DTG/3TC FDC were employed for exposure prediction and incorporated relative bioavailability data. The predicted plasma exposures of ABC, DTG, and 3TC for FDC doses were consistent with those observed for the single entities in pediatric and adult studies. Thus, safety and efficacy observed in the individual component studies could be adequately extrapolated to the FDC that results in similar exposure. The current work demonstrates the significance of MIDD approaches in facilitating expedited access to child-friendly formulations in the HIV-1 therapeutic area.

Bridging dolutegravir clinical viral response across doses and formulations using model-based exposure-response analysis in pediatrics.

OBJECTIVE: Dolutegravir (DTG) is a once-daily HIV-1 integrase inhibitor approved for the treatment of HIV-1 infection in adults and children from 4 weeks of age. The posology of DTG in children has been driven by exposure-matching relative to the adult dose for efficacy and safety. However, higher variability in pediatric exposures raises concern that efficacy may not be reliably extrapolated from adult trials. Therefore, we evaluated the relationship between DTG exposure and virologic response in children. DESIGN/METHODS: A population exposure-response analysis using logistic regression for virologic response was undertaken based on DTG exposure and covariate data from 146 pediatric participants with HIV-1 from age at least 4 weeks to less than 18 years treated for up to 48 weeks with DTG in IMPAACT P1093 study. RESULTS: None of the DTG exposure metrics were predictive of virologic response over the range of exposures in this analysis. Of the covariates tested, viral load at least 100 000 copies/ml at enrolment was a significant predictor of virologic response showing a lower probability of achieving a virologic response of HIV-1 RNA less than 50 copies/ml compared with participants with viral load less than 100 000 copies/ml at enrolment. Baseline viral load was also a significant predictor at week 48 whereby the probability of achieving a virologic response at week 48 decreased with increasing baseline viral load. CONCLUSION: This exposure-response analysis suggests that DTG exposures in children are all above the plateau of the exposure-response relationship. These results suggest that matching pediatric pharmacokinetic exposure parameters to those in adults is a reasonable approach for dose determination of DTG-containing formulations in pediatrics.

Pharmacokinetics, safety, and tolerability of dispersible and immediate-release abacavir, dolutegravir, and lamivudine tablets in children with HIV (IMPAACT 2019): week 24 results of an open-label, multicentre, phase 1-2 dose-confirmation study.

BACKGROUND: Child-friendly fixed-dose combination (FDC) antiretroviral therapy (ART) options are limited. We evaluated the pharmacokinetics, safety, and tolerability of dispersible and immediate-release FDC abacavir, dolutegravir, and lamivudine taken once per day in children younger than 12 years with HIV. METHODS: IMPAACT 2019 was an international, phase 1-2, multisite, open-label, non-comparative dose-confirmation study of abacavir, dolutegravir, and lamivudine in children younger than 12 years. Participants were enrolled across five weight bands: those weighing 6 kg to less than 25 kg received abacavir (60 mg), dolutegravir (5 mg), and lamivudine (30 mg) dispersible tablets (three to six tablets depending on body weight), and those weighing 25 kg to less than 40 kg received abacavir (600 mg), dolutegravir (50 mg), and lamivudine (300 mg) in an immediate-release tablet. At entry, participants were ART naive or ART experienced and virologically suppressed on stable ART for 6 months or more. Dose confirmation was based on pharmacokinetic and safety criteria in the first five to seven participants in each weight band to week 4; all participants were followed up to week 48. We present the results for the primary objectives to assess pharmacokinetics, confirm dosing, and evaluate safety through 24 weeks across all weight bands. The trial is registered with ClinicalTrials.gov (NCT03760458). FINDINGS: 57 children were enrolled and initiated study drug (26 [46%] female and 31 [54%] male; 37 [65%] Black, 18 [32%] Asian, and 1 [2%] had race reported as unknown). Within each weight band, 6 kg to less than 10 kg, 10 kg to less than 14 kg, 14 kg to less than 20 kg, 20 kg to less than 25 kg, and 25 kg or higher: the geometric mean dolutegravir area under the concentration time curve over the 24 h dosing interval (AUC0-24 h) was 75·9 h·µg/mL (33·7%), 91·0 h·µg/mL (36·5%), 71·4 h·µg/mL (23·5%), 84·4 h·µg/mL (26·3%), and 71·8 h·µg/mL (13·9%); dolutegravir concentrations 24 h after dosage (C24 h) were 0·91 µg/mL (67·6%), 1·22 µg/mL (77·5%), 0·79 µg/mL (44·2%), 1·35 µg/mL (95·5%), and 0·98 µg/mL (27·9%); abacavir AUC0-24 h was 17·7 h·µg/mL (38·8%), 19·8 h·µg/mL (50·6%), 15·1 h·µg/mL (40·3%), 17·4 h·µg/mL (19·4%), and 25·7 h·µg/mL (14·6%); lamivudine AUC0-24 h was 10·7 h·µg/mL (46·0%), 14·2 h·µg/mL (23·9%), 13·0 h·µg/mL (15·6%), 14·5 h·µg/mL (16·6%), and 21·7 h·µg/mL (26·2%), respectively. Pharmacokinetic targets and safety criteria were met within each weight band, and thus dosing of abacavir, dolutegravir, and lamivudine was confirmed at the originally selected doses. 54 (95%) of participants were treatment experienced and all who continued taking the study drug remained virologically suppressed (<200 copies per mL) through week 24. Virological suppression was achieved in two of three participants who were ART naive by week 24. There were no grade 3 or higher adverse events related to abacavir, dolutegravir, and lamivudine and no discontinuations because of toxicity to week 24. Both formulations were well tolerated. INTERPRETATION: Dosing of abacavir, dolutegravir, and lamivudine was confirmed in children weighing 6 kg to less than 40 kg, and both FDC formulations were safe, well tolerated, and efficacious through 24 weeks of treatment. These findings support global efforts to expand the availability of FDC abacavir, dolutegravir, and lamivudine to children with HIV. FUNDING: National Institute of Allergy and Infectious Diseases, the Eunice Kennedy Shriver National Institute of Child Health and Human Development, the National Institute of Mental Health, ViiV Healthcare, and GlaxoSmithKline.

Development of Dolutegravir Single-entity and Fixed-dose Combination Formulations for Children.

BACKGROUND: The World Health Organization (WHO) 2019 antiretroviral treatment guidelines recommend use of optimal treatment regimens in all populations. Dolutegravir-based regimens are the preferred first-line and second-line treatment in infants and children with HIV 4 weeks of age and above. There is an urgent need for optimal pediatric formulations of dolutegravir as single-entity (SE) and fixed-dose combination (FDC) to ensure correct dosing and adherence for swallowing and palatability. This article outlines the chronology of dolutegravir pediatric formulation development as granules and conventional and dispersible tablets in a total of 5 pharmacokinetic studies evaluating the relative bioavailability of dolutegravir SE and FDC formulations in healthy adults. METHODS: The relative bioavailability studies were 2-part, Phase I, open-label, randomized studies in healthy adults. Dolutegravir SE study compared conventional dolutegravir 50 and 25 mg with equivalent conventional 10-mg and dispersible 5-mg tablets, respectively. Subsequently, dolutegravir FDC study compared adult FDC of abacavir/dolutegravir/lamivudine and adult FDC of dolutegravir/lamivudine with their respective pediatric FDC formulations, taken as dispersion immediately or swallowed whole. RESULTS: As observed in previous studies, dolutegravir administered as dispersion (granules/dispersible tablets) showed relatively higher bioavailability compared with conventional tablets. The bioavailability of dolutegravir dispersible tablets (both SE and FDC) was approximately 1.6-fold higher when compared with conventional tablets. In addition, the bioavailability of abacavir/lamivudine was not impacted by dispersible formulation. CONCLUSIONS: These studies demonstrate the successful development of pediatric dolutegravir-containing formulations as SE and FDC that permit pediatric dosing in line with WHO recommendations.

Pharmacokinetics, safety, tolerability, and antiviral activity of dolutegravir dispersible tablets in infants and children with HIV-1 (IMPAACT P1093): results of an open-label, phase 1-2 trial.

BACKGROUND: Safe and potent antiretroviral medications in child-friendly formulations are needed to treat young children living with HIV-1. We aimed to select dosing for a dispersible tablet formulation of dolutegravir that achieved pharmacokinetic exposures similar to those in adults, and was safe and well tolerated in young children. METHODS: International Maternal Pediatric Adolescent AIDS Clinical Trial (IMPAACT) P1093 is a phase 1-2 ongoing multicentre, open-label, non-comparative study of dolutegravir. A 5 mg dispersible tablet formulation of dolutegravir was studied in children aged 4 weeks to less than 6 years old, weighing at least 3 kg, with HIV RNA of greater than 1000 copies per mL and no previous treatment with integrase strand transfer inhibitor recruited from IMPAACT clinical research sites in Africa, the Americas, and Asia. Doses were selected on the basis of intensive pharmacokinetic evaluation on days 5-10, with safety and tolerability assessed up to 48 weeks. The primary objectives of this study are to evaluate the pharmacokinetics of dolutegravir in combination with optimised background therapy and to establish the dose of dolutegravir that achieves the targeted 24-h trough concentration and 24-h area under the curve for infants, children, and adolescents with HIV-1, to establish the safety and tolerability of dolutegravir at 24 and 48 weeks, and to select a dose that achieves similar exposure to the dolutegravir 50 mg once daily dose in adults. This analysis included participants treated with the proposed dose of dolutegravir dispersible tablets in two stages for each of three age cohorts. This trial is registered at ClinicalTrials.gov (NCT01302847) and is ongoing. FINDINGS: We recruited 181 participants from April 20, 2011, to Feb 19, 2020; of these, 96 received dolutegravir dispersible tablets. This analysis included 73 (35, 48% female) participants who received the final proposed dose with median (range) age of 1 year (0·1 to 6·0), weight (minimum-maximum) of 8·5 kg (3·7 to 18·5), plasma HIV-1 RNA concentration of 4·2 log10 copies per mL (2·1 to 7·0), and CD4% of 24·0% (0·3 to 49·0); 64 (87·7%) were treatment-experienced. The selected dose within each age cohort (≥2 years to <6 years, ≥6 months to <2 years of age and ≥4 weeks to <6 months) achieved geometric mean trough (ng/mL) of 688, 1179, and 1446, and 24 h area-under-the-curve (h·mg/L) of 53, 74, and 65, respectively. No grade 3 or worse adverse events were attributed to dolutegravir. INTERPRETATION: In this study, the proposed once daily dosing of dolutegravir dispersible tablets provided drug exposures similar to those for adults, and was safe and well tolerated. These data support the use of dolutegravir dispersible tablets as first-line or second-line treatment for infants and children aged less than 6 years living with HIV-1. FUNDING: National Institute of Allergy and Infectious Diseases, the Eunice Kennedy Shriver National Institute of Child Health and Human Development, the National Institute of Mental Health, and ViiV Healthcare-GlaxoSmithKline.

Advances and failures in preventing perinatal human immunodeficiency virus infection.

An estimated 2.5 million children are currently living with HIV, the vast majority as a result of mother-to-child transmission. Prevention of perinatal HIV infection has been immensely successful in developed countries. A comprehensive package of services, including maternal and infant antiretroviral therapy, elective cesarean section, and avoidance of breast-feeding, has resulted in transmission rates of less than 2%. However, in developing countries, access to such services is often not available, as demonstrated by the fact that the vast majority of children with HIV live in Africa. Over the past few years, many developing nations have made great strides in improving access to much-needed services. Notably, in eastern and southern Africa, the regions most affected by HIV, mother-to-child-transmission coverage rates for HIV-positive women increased from 11% in 2004 to 31% in 2006. These successes are deserving of recognition, while not losing sight of the fact that much remains to be done; currently, an estimated 75% of pregnant women worldwide have an unmet need for antiretroviral therapy. Further work is needed to determine the optimal strategy for reducing perinatal transmission among women in resource-poor settings, with a particular need for reduction of transmission via breast-feeding.

Establishment of haematological and immunological reference values for healthy Tanzanian children in Kilimanjaro Region.

OBJECTIVE: To determine the normal haematological and immunological reference intervals for healthy Tanzanian children. METHODS: We analysed data from 655 HIV-seronegative, healthy children from 1 month to 18 years of age from the Kilimanjaro Region of Tanzania for this cross-sectional study. Median and 95% reference ranges were determined for haematological and immunological parameters and analysed by age cohorts, and by gender for adolescents. RESULTS: Median haemoglobin (Hb) and haematocrit (Hct) for all age groups were higher than established East African reference intervals. Compared to U.S. intervals, reference ranges encompassed lower values for Hb, Hct, mean corpuscular volume, and platelets. Applying the U.S. National Institute of Health Division of AIDS (DAIDS) adverse event grading criteria commonly used in clinical trials to the reference range participants, 128 (21%) of 619 children would be classified as having an adverse event related to Hb level. CD4-positive T-lymphocyte absolute counts declined significantly with increasing age (P < 0.0001). For those aged under five years, CD4-positive T-lymphocyte percentages are lower than established developed country medians. CONCLUSIONS: Country-specific reference ranges are needed for defining normal laboratory parameters among children in Africa. Knowledge of appropriate reference intervals is critical not only for providing optimal clinical care, but also for enrolling children in medical research. Knowledge of normal CD4-positive T-lymphocyte parameters in this population is especially important for guiding the practice of HIV medicine in Tanzania.

Long-Term Safety and Efficacy of Dolutegravir in Treatment-Experienced Adolescents With Human Immunodeficiency Virus Infection: Results of the IMPAACT P1093 Study.

BACKGROUND: P1093 is an ongoing phase I/II multicenter open-label study of dolutegravir plus an optimized background regimen in age-defined pediatric cohorts; here we report the long-term safety and virologic efficacy outcomes for the oldest cohort. METHODS: The study enrolled human immunodeficiency virus type 1 (HIV-1)-infected treatment-experienced adolescents aged 12 to <18 years, with an HIV-1 RNA level ≥1000 copies/mL . Cumulative safety and HIV-1 RNA outcomes were assessed once the last enrolled participant reached 144 weeks of follow-up. RESULTS: Among 23 adolescents enrolled, 16 remained in the study at least 144 weeks; the median follow-up was 153 weeks (range, 55-193 weeks). Dolutegravir was well tolerated, with grade 3 clinical adverse events in 5 participants, grade 3 laboratory abnormalities in 3, and grade 4 laboratory abnormalities in 1; none of the adverse events or abnormalities were judged to be treatment related. In an-intent-to-treat analysis, an HIV-1 RNA level <400 copies/mL at week 144 was achieved in 43% (10 of 23 participants; 95% confidence interval, 23.2%-65.5%); in addition, 35% (8 of 23; 16.4%-57.3%) had an HIV-1 RNA level <50 copies/mL. Nine participants (39%) discontinued study treatment before 144 weeks, but none because of adverse events or drug intolerance. All participants with sustained virologic control had excellent adherence; most who experienced virologic failure had adherence levels <90%. HIV-1 genotypic drug resistance testing was available at time of failure from 6 participants; 1 had evolution in integrase resistance with E138T, S147G, and R263K mutations at week 192 and phenotypic dolutegravir resistance of a 5.1-fold change. CONCLUSIONS: Dolutegravir plus an optimized background regimen seemed safe, well tolerated, and efficacious in this cohort of treatment-experienced HIV-1-infected adolescents. Adherence remains problematic in this population. CLINICAL TRIALS REGISTRATION: NCT01302847.

Effects of Low- and High-Mineral Content Water on the Relative Bioavailability of a Coformulated Abacavir/Dolutegravir/Lamivudine Dispersible Tablet in Healthy Adults.

BACKGROUND: The fixed-dose combination (FDC) tablet formulation of abacavir/dolutegravir/lamivudine is indicated for the treatment of HIV-1 infection in adults and pediatric patients weighing ≥40 kg. Alternative formulations with acceptable palatability and convenient dosing are needed for children who require smaller doses and have difficulty swallowing tablets. SETTING: A phase 1, open-label, randomized study was conducted in healthy adults to evaluate the relative bioavailability of a novel dispersible FDC tablet of abacavir 150 mg/dolutegravir 10 mg/lamivudine 75 mg administered under 4 different dosing conditions compared with dolutegravir plus abacavir/lamivudine nondispersible, film-coated tablets. METHODS: The test treatments were 4 dispersible FDC tablets reconstituted in water with high- or zero-mineral content and administered either immediately or after a 30-minute delay. The reference treatment was 4 nondispersible dolutegravir 10-mg tablets plus 1 nondispersible abacavir 600-mg/lamivudine 300-mg tablet administered with zero-mineral content water. The primary endpoints were area under the concentration-time curve from time 0 extrapolated to infinity and the maximum observed plasma concentration. RESULTS: Following administration of dispersible abacavir/dolutegravir/lamivudine, the relative bioavailability of dolutegravir was approximately 50% higher. Abacavir and lamivudine demonstrated bioequivalence when administered as the dispersible FDC tablet compared with coadministration of dolutegravir plus abacavir/lamivudine nondispersible, film-coated tablets. Neither the mineral content of the water nor dosing times affected the pharmacokinetics of individual components. The dispersible tablet was safe and well tolerated, and the palatability was acceptable. CONCLUSIONS: These pharmacokinetic results support further development of a dispersible FDC tablet of abacavir/dolutegravir/lamivudine for future use in pediatric patients.

Relative Bioavailability of a Dolutegravir Dispersible Tablet and the Effects of Low- and High-Mineral-Content Water on the Tablet in Healthy Adults.

Dolutegravir (DTG) is approved in the United States to treat HIV-1-infected patients weighing ≥30 kg. A dispersible DTG tablet formulation was recently developed for pediatric patients. This study compares the pharmacokinetics (PK) of the dispersible tablet with that of a previously evaluated granule formulation. In this randomized, open-label, crossover study, 15 healthy adults received single oral doses of DTG 20 mg every 7 days across 5 treatment arms: granules consumed immediately after mixture with purified water, dispersible DTG consumed immediately after reconstitution in low-mineral-content (LMC) or high-mineral-content (HMC) water, and dispersible DTG consumed 30 minutes after dispersal in LMC or HMC water. Primary endpoints were bioavailability of immediately consumed dispersible tablet in LMC water relative to granule formulation reconstituted in purified water and PK of the dispersible tablet. Secondary endpoints included tolerability and palatability. The DTG dispersible tablet showed equivalent exposures to the granule formulation with geometric least-squares mean treatment ratios of 1.06 and 1.12 for AUC0-∞ and Cmax , respectively. DTG PK parameters were unaffected by mineral content or the 30-minute delay. Adverse events were mild; only nausea (n = 1) was considered drug related. DTG exposure observed with the dispersible tablet supports evaluation of this formulation for further development.

Fixed-dose combination dolutegravir, abacavir, and lamivudine versus ritonavir-boosted atazanavir plus tenofovir disoproxil fumarate and emtricitabine in previously untreated women with HIV-1 infection (ARIA): week 48 results from a randomised, open-label, non-inferiority, phase 3b study.

BACKGROUND: Dolutegravir is a once-daily integrase strand transfer inhibitor with no need for pharmacokinetic boosting that is approved for the treatment of HIV-1 infection. Because women are often under-represented in HIV clinical trials, we addressed the safety and efficacy of dolutegravir in women with HIV-1. METHODS: The ARIA study is a randomised, open-label, multicentre, active-controlled, parallel-group, non-inferiority phase 3b study done in 86 hospital and university infectious disease clinics, local health clinics, and private infectious disease clinics in 12 countries and one US territory, in North America, South America, Europe, Africa, and Asia. Eligible participants were women aged 18 years or older who had HIV-1 RNA viral loads of 500 copies per mL or greater, had received 10 days or less of previous antiretroviral therapy, and had tested negative for the HLA-B*5701 allele. Pregnant women were excluded. Eligible women were randomly assigned (1:1) to receive either a single-tablet regimen of dolutegravir plus abacavir and lamivudine once a day (dolutegravir group) or a three-tablet combination of ritonavir-boosted atazanavir plus coformulated tenofovir disoproxil fumarate and emtricitabine once a day (atazanavir group). Random treatment group assignment was stratified by plasma HIV-1 RNA viral loads and CD4 cell count at baseline. The primary endpoint was the proportion of participants with HIV-1 RNA viral loads of less than 50 copies per mL at week 48 in all participants who received at least one dose of study medication (intention-to-treat exposed population). We used a non-inferiority margin of -12%. Investigators monitored adverse events to assess safety. This study is registered with ClinicalTrials.gov, number NCT01910402. FINDINGS: Between Aug 22, 2013, and Sept 22, 2015, of 705 women assessed, 499 were randomly assigned to either the dolutegravir group (n=250) or the atazanavir group (n=249); two participants from each group were randomised to treatment but did not receive study medication. At week 48, 203 (82%) of 248 participants in the dolutegravir group compared with 176 (71%) of 247 in the atazanavir group had HIV-1 RNA viral loads of less than 50 copies per mL (mean difference 10·5%, 95% CI 3·1-17·8, p=0·005). One participant in the atazanavir group had nucleoside reverse transcriptase inhibitor-associated resistance that led to reduced emtricitabine susceptibility. Adverse events were similar between the dolutegravir and atazanavir groups; the most common were nausea (46 [19%] of 248 in the dolutegravir group vs 49 [20%] of 247 in the atazanavir group) and headache (28 [11%] vs 32 [13%]). Fewer participants in the dolutegravir group than the atazanavir group reported drug-related adverse events (83 [33%] vs 121 [49%]) or adverse events that led to discontinuation (ten [4%] vs 17 [7%]). One death was reported in each treatment group, but neither was considered related to the study medications. INTERPRETATION: The non-inferior efficacy and similar safety profile of the dolutegravir combined regimen compared with the atazanavir regimen support the use of dolutegravir for HIV-1 infection in treatment-naive women. FUNDING: ViiV Healthcare.

HIV Resistance and Prevention of Mother-to-Child Transmission Regimen in HIV-Infected Infants in Northern Tanzania.

Prevention of mother-to-child transmission (PMTCT) guidelines recommend that all HIV-infected pregnant women receive antiretroviral therapy (Option B) and HIV-infected infants should initiate therapy with a protease inhibitor-based regimen; however, implementation of these guidelines has lagged in many resource-limited settings. Tanzania only recently implemented these guidelines with little country-specific data to inform whether HIV non-nucleoside reverse transcriptase inhibitor (NNRTI) resistance was present among infected infants under the Option A guidelines. This study aimed to identify primary resistance mutations in HIV-infected infants and to identify risk of nevirapine (NVP) resistance based on maternal and infant NVP exposure. Infant dried blood spots (DBSs) were sent to the zonal reference laboratory at Kilimanjaro Christian Medical Centre Clinical Laboratory and underwent DNA polymerase chain reaction testing for HIV as standard of care. Using the clinical laboratory registry, HIV-positive DBS cards, stored at ambient temperature, were identified and sent for further viral load testing, nucleotide sequencing, and analysis. Clinical information was obtained from the PMTCT clinical sites and the National PMTCT registry for information regarding maternal and infant demographics and PMTCT treatment regimen. Results demonstrated that infants exposed to NVP were more likely to have high level resistance mutations (HLRMs) to NVP than those infants not exposed to NVP (p = .002). The most common HLRMs to NVP were K103 N, Y181C, and Y188 L. HIV subtype A was most common, followed by subtype C. Approximately one-third of HIV-infected infants had documented referral to HIV care. This study demonstrated the ongoing need to scale up and strengthen points along the PMTCT continuum and supported the recommendation for all HIV-infected infants to initiate a lopinavir/ritonavir-based antiretroviral therapy regimen.

Effect of Cabotegravir on Cardiac Repolarization in Healthy Subjects.

A randomized, partial-blind, repeat-dose, 3-period crossover study (NCT02027454) assessed the effect of cabotegravir on QT interval in healthy subjects. To achieve a supratherapeutic dose, each subject received cabotegravir 150 mg (30 mg × 5 tablets) every 12 hours for a total of 3 doses over 2 days, matching placebo (every 12 hours) over 2 days, or a single open-label 400-mg dose of the positive control moxifloxacin, with a 21-day washout between treatments. Blood samples for pharmacokinetic analyses were collected up to 24 hours after the third dose on day 2. QT interval data were obtained by continuous Holter monitoring for approximately 24 hours at baseline (day -1) and from 2 hours before to 24 hours after the third dose on day 2. Plasma cabotegravir exposure was approximately 3-fold above clinically relevant doses. After 3 doses of 150 mg of cabotegravir administered every 12 hours, all upper limits of 2-sided 90% confidence intervals for ΔΔQTcF (difference in time-matched change from baseline for QTcF between cabotegravir and placebo) were <10 milliseconds. There was no relationship between cabotegravir plasma concentrations and ΔΔQTcF. No subject receiving cabotegravir had a QTcF value > 450 milliseconds. There were no serious or grade 3 or 4 adverse events or clinically significant changes in laboratory values, vital signs, or electrocardiogram results. These data demonstrate that cabotegravir at a supratherapeutic dose had no effect on cardiac repolarization.

A Review of Human Herpesvirus 8, the Kaposi's Sarcoma-Associated Herpesvirus, in the Pediatric Population.

Human herpesvirus 8 (HHV-8), also known as Kaposi's sarcoma (KS)-associated herpesvirus, is the etiologic agent responsible for all types of KS. Although the majority of pediatric KS cases occur in sub-Saharan Africa, a rise in pediatric transplant KS has been reported in developed countries. In addition, HHV-8 is increasingly described as an infectious cause of hemophagocytic lymphohistiocytosis in children. Transmission of HHV-8 among children is poorly understood; however, the literature strongly suggests that horizontal transmission plays a critical role. Acute infection with HHV-8 and progression to KS in children may be different than in adults, and diagnosis may be overlooked. Currently, neither adult nor pediatric treatment guidelines exist. This review provides an overview of HHV-8 disease in children as it relates to epidemic KS, transplant KS, and other disease manifestations. The current state of the literature is reviewed and knowledge gaps are identified for future exploration.

Progress in the prevention of mother to child transmission of HIV in three regions of Tanzania: a retrospective analysis.

BACKGROUND: Mother to child transmission (MTCT) of HIV-1 remains an important problem in sub-Saharan Africa where most new pediatric HIV-1 infections occur. Early infant diagnosis of HIV-1 using dried blood spot (DBS) PCR among exposed infants provides an opportunity to assess current MTCT rates. METHODS: We conducted a retrospective data analysis on mother-infant pairs from all PMTCT programs in three regions of northern Tanzania to determine MTCT rates from 2008-2010. Records of 3,016 mother-infant pairs were assessed to determine early transmission among HIV-exposed infants in the first 75 days of life. RESULTS: Of 2,266 evaluable infants in our cohort, 143 had a positive DBS PCR result at ≤ 75 days of life, for an overall transmission rate of 6.3%. Transmission decreased substantially over the period of study as more effective regimens became available. Transmission rates were tightly correlated to maternal regimen: 14.9% (9.5, 20.3) of infants became infected when women received no therapy; 8.8% (6.9, 10.7) and 3.6% (2.4, 4.8) became infected when women received single-dose nevirapine (sdNVP) or combination prophylaxis, respectively; the lowest MTCT rates occurred when women were on HAART, with 2.1% transmission (0.3, 3.9). Treatment regimens changed dramatically over the study period, with an increase in combination prophylaxis and a decrease in the use of sdNVP. Uptake of DBS PCR more than tripled over the period of study for the three regions surveyed. CONCLUSIONS: Our study demonstrates significant reductions in MTCT of HIV-1 in three regions of Tanzania coincident with increased use of more effective PMTCT interventions. The changes we demonstrate for the period of 2008-2010 occurred prior to major changes in WHO PMTCT guidelines.