Dolutegravir twice-daily dosing in children with HIV-associated tuberculosis: a pharmacokinetic and safety study within the open-label, multicentre, randomised, non-inferiority ODYSSEY trial

Disparities in access to Dolutegravir in West African children, adolescents and young adults aged 0-24 years living with HIV. A IeDEA Pediatric West African cohort analysis

Introduction

We describe the 24-month incidence of Dolutegravir (DTG)-containing antiretroviral treatment (ART) initiation since its introduction in 2019 in the pediatric West African IeDEA cohorts.

Methods

We included all patients aged 0-24 years on ART, from nine clinics in Côte d'Ivoire (n=4), Ghana, Nigeria, Mali, Benin, and Burkina Faso. Baseline varied by clinic and was defined as date of first DTG prescription; patients were followed-up until database closure/death/loss to follow-up (LTFU, no visit ≥ 7 months), whichever came first. We computed the cumulative incidence function for DTG initiation; associated factors were explored in a shared frailty model, accounting for clinic heterogeneity.

Results

Since 2019, 3,350 patients were included; 49% were female;79% had been on ART ≥ 12 months. Median baseline age was 12.9 years (IQR: 9-17). Median follow-up was 14 months (IQR: 7-22). The overall cumulative incidence of DTG initiation reached 35.5% (95% CI: 33.7-37.2) and 56.4% (95% CI: 54.4-58.4) at 12 and 24 months, respectively. In univariate analyses, those aged <5 years and females were overall less likely to switch. Adjusted on ART line and available viral load (VL) at baseline, females >10 years were less likely to initiate DTG compared to males of the same age (aHR among 10-14 years: 0.62, 95% CI: 0.54-0.72; among ≥15 years: 0.43, 95% CI: 0.36-0.50), as were those with detectable VL (> 50 copies/mL) compared to those in viral suppression (aHR: 0.86, 95% CI: 0.77-0.97) and those on PIs compared to those on NNRTIs (aHR after 12 months of roll-out: 0.75, 95% CI: 0.65-0.86). Conclusion: Access to paediatric DTG was incomplete and unequitable in West African settings: children <5years, females ≥ 10 years and those with detectable viral load were least likely to access DTG. Maintained monitoring and support of treatment practices is required to better ensure universal and equal access.

Key messages

What is already known on this topic?: Dolutegravir (DTG)-based ART regimens are recommended as the preferred first-line ART regimens recommended by the World Health Organisation in all people living with HIV since 2018, with a note of caution for pregnant women, then confirmed in all children with approved DTG dosing and adolescents since 2019.Deployment of universal DTG access in adults in West Africa has faced challenges such as infrastructure challenges, and healthcare system disparities, and was hindered by initial perinatal safety concerns affecting greatly women of childbearing age.Specific data on access to DTG in children, adolescents and young adults in West Africa is limited.What this study adds ?: This study describes the dynamic of the DTG roll-out over the first 24 months and its correlates since 2019 in a large West African multicentric cohort of children, adolescents and youth.We observed a rapid scale-up of DTG among children, adolescents and young adults living with HIV in West Africa, despite the COVID-19 pandemic.However, DTG access after 24 months was incomplete and unequitable, with adolescent girls and young women being less likely to initiate DTG compared to males, as were those with a detectable viral load (> 50 copies/mL) compared to those in success.Younger children < 5 years were also less likely to initiate DTG, explained by the later approval of paediatric formulations and their low availability.How this study might affect research, practice or policy?: Maintained monitoring, training and updating guidance for healthcare workers is essential to ensure universal access to DTG, especially for females, for whom inequity begins age 10 years.Efforts to improve access to universal DTG in West Africa require multifaceted interventions including healthcare infrastructure improvement and facilitation of paediatric antiretroviral forecasting and planification.

Twice-Daily Dosing of Dolutegravir in Infants on Rifampicin Treatment: A Pharmacokinetic Substudy of the EMPIRICAL Trial

BACKGROUND

We evaluated dolutegravir pharmacokinetics in infants with human immunodeficiency virus (HIV) receiving dolutegravir twice daily (BID) with rifampicin-based tuberculosis (TB) treatment compared with once daily (OD) without rifampicin.

METHODS

Infants with HIV aged 1-12 months, weighing ≥3 kg, and receiving dolutegravir BID with rifampicin or OD without rifampicin were eligible. Six blood samples were taken over 12 (BID) or 24 hours (OD). Dolutegravir pharmacokinetic parameters, HIV viral load (VL) data, and adverse events (AEs) were reported.

RESULTS

Twenty-seven of 30 enrolled infants had evaluable pharmacokinetic curves. The median (interquartile range) age was 7.1 months (6.1-9.9), weight was 6.3 kg (5.6-7.2), 21 (78%) received rifampicin, and 11 (41%) were female. Geometric mean ratios comparing dolutegravir BID with rifampicin versus OD without rifampicin were area under curve (AUC)0-24h 0.91 (95% confidence interval, .59-1.42), Ctrough 0.95 (0.57-1.59), Cmax 0.87 (0.57-1.33). One infant (5%) receiving rifampicin versus none without rifampicin had dolutegravir Ctrough <0.32 mg/L, and none had Ctrough <0.064 mg/L. The dolutegravir metabolic ratio (dolutegravir-glucuronide AUC/dolutegravir AUC) was 2.3-fold higher in combination with rifampicin versus without rifampicin. Five of 82 reported AEs were possibly related to rifampicin or dolutegravir and resolved without treatment discontinuation. Upon TB treatment completion, HIV viral load was <1000 copies/mL in 76% and 100% of infants and undetectable in 35% and 20% of infants with and without rifampicin, respectively.

CONCLUSIONS

Dolutegravir BID in infants receiving rifampicin resulted in adequate dolutegravir exposure, supporting this treatment approach for infants with HIV-TB coinfection.

HIV drug resistance among patients experiencing antiretroviral therapy failure in Russia, 2019-2021

Increasing HIV drug resistance is an important public health concern. The current study aimed to assess HIV drug resistance among people who live with HIV (PLWH) experiencing virological failure. Blood samples and epidemiological characteristics were collected in four Siberian regions from PLWH experiencing ART failure. Partial pol gene sequences were obtained for the study individuals. Drug resistance mutations (DRMs) were predicted using the Stanford HIVdb Program. The association of HIV DRM with epidemiological characteristics was estimated using logistic regression analysis. Further analysis was performed for children (0-14 y old) and adults (≥15 y old) separately. In total, 815 (89.4%) patients were included in the final dataset. Overall, 501 (61.5%) patients had DRM detected. NRTI DRM was more common in children, while NRTI+NNRTI DRM was more frequent in adults (P < 0.001). Krasnoyarsk region, male sex and high viral load were positively associated with the presence of DRM in adults, while higher CD4 cell count and PI/INSTI-based ART had a negative association. No association between epidemiological characteristics and DRM was identified in children. The remaining 38.5% of patients with virological failure had no DRM detected; those patients were likely to have insufficient ART adherence. Most (55.5%) patients had HIV CRF63_02A6, followed by sub-subtype A6 (39.2%). This study revealed poor ART adherence as a main factor driving ART failure among PLWH in the Siberian region. DRM was detected in over 60% of PLWH experiencing ART failure. The current results highlight an urgent need for the introduction of special programs focusing on ART adherence improvement.

Pharmacokinetic Data of Dolutegravir in Second-line Treatment of Children With Human Immunodeficiency Virus: Results From the CHAPAS4 Trial

BACKGROUND

Dolutegravir (DTG), combined with a backbone of 2 nucleoside reverse transcriptase inhibitors, is currently the preferred first-line treatment for human immunodeficiency virus (HIV) in childhood. CHAPAS4 is an ongoing randomized controlled trial investigating second-line treatment options for children with HIV. We did a nested pharmacokinetic (PK) substudy within CHAPAS4 to evaluate the DTG exposure in children with HIV taking DTG with food as part of their second-line treatment.

METHODS

Additional consent was required for children on DTG enrolled in the CHAPAS4 trial to participate in this PK substudy. Children weighing 14-19.9 kg took 25 mg DTG as dispersible tablets and children ≥20 kg took 50 mg film-coated tablets. Steady-state 24-hour DTG plasma concentration-time PK profiling was done at t = 0 and 1, 2, 4, 6, 8, 12, and 24 hours after observed DTG intake with food. Reference adult PK data and pediatric data from the ODYSSEY trial were used primarily for comparison. The individual target trough concentration (Ctrough) was defined as 0.32 mg/L.

RESULTS

Thirty-nine children on DTG were included in this PK substudy. The geometric mean (GM) area under the concentration-time curve over the dosing interval (AUC0-24h) was 57.1 hours × mg/L (coefficient of variation [CV%], 38.4%), which was approximately 8% below the average AUC0-24h in children in the ODYSSEY trial with comparable dosages, but above the adult reference. The GM (CV%) Ctrough was 0.82 mg/L (63.8%), which was comparable to ODYSSEY and adult reference values.

CONCLUSIONS

This nested PK substudy shows that the exposure of DTG taken with food in children on second-line treatment is comparable with that of children in the ODYSSEY trial and adult references. Clinical Trials Registration.ISRCTN22964075.

Biktarvy for the treatment of HIV infection: Progress and prospects

Bictegravir (BIC), a second-generation integrase strand-transfer inhibitor (INSTI) with high resilience to INSTI-resistance mutations, is integrated as a key component of Biktarvy® - a fixed-dose once-daily triple-drug regimen of bictegravir (BIC), emtricitabine (FTC) plus tenofovir alafenamide (TAF). Based on the accumulated evidence from HIV clinical trials and real-world studies, the clinical effectiveness of BIC + FTC + TAF has been proven non-inferior to other fixed-dose once-daily combinations such as dolutegravir + FTC + TAF and dolutegravir + abacavir + lamivudine. Biktarvy also shows limited drug-drug interactions and a high barrier to drug resistance. According to recent HIV guidelines, BIC + FTC + TAF is recommended as initial and long-term therapy for the treatment of HIV infection. For the pre-exposure prophylaxis, tenofovir disoproxil fumarate (TDF) or tenofovir alafenamide (TAF) remains advisable, but BIC may be possibly added to TDF or TAF. In the development of a long-acting once-monthly regimen, the novel nano-formulation of BIC + FTC + TAF could be possibly developed in the future.

Inadequate Lopinavir Concentrations With Modified 8-Hourly Lopinavir/Ritonavir 4:1 Dosing During Rifampicin-based Tuberculosis Treatment in Children Living With HIV

BACKGROUND

Lopinavir/ritonavir plasma concentrations are profoundly reduced when co-administered with rifampicin. Super-boosting of lopinavir/ritonavir is limited by nonavailability of single-entity ritonavir, while double-dosing of co-formulated lopinavir/ritonavir given twice-daily produces suboptimal lopinavir concentrations in young children. We evaluated whether increased daily dosing with modified 8-hourly lopinavir/ritonavir 4:1 would maintain therapeutic plasma concentrations of lopinavir in children living with HIV receiving rifampicin-based antituberculosis treatment.

METHODS

Children with HIV/tuberculosis coinfection weighing 3.0 to 19.9 kg, on rifampicin-based antituberculosis treatment were commenced or switched to 8-hourly liquid lopinavir/ritonavir 4:1 with increased daily dosing using weight-band dosing approach. A standard twice-daily dosing of lopinavir/ritonavir was resumed 2 weeks after completing antituberculosis treatment. Plasma sampling was conducted during and 4 weeks after completing antituberculosis treatment.

RESULTS

Of 20 children enrolled; 15, 1-7 years old, had pharmacokinetics sampling available for analysis. Lopinavir concentrations (median [range]) on 8-hourly lopinavir/ritonavir co-administered with rifampicin (n = 15; area under the curve 0-24 55.32 mg/h/L [0.30-398.7 mg/h/L]; C max 3.04 mg/L [0.03-18.6 mg/L]; C 8hr 0.90 mg/L [0.01-13.7 mg/L]) were lower than on standard dosing without rifampicin (n = 12; area under the curve 24 121.63 mg/h/L [2.56-487.3 mg/h/L]; C max 9.45 mg/L [0.39-26.4 mg/L]; C 12hr 3.03 mg/L [0.01-17.7 mg/L]). During and after rifampicin cotreatment, only 7 of 15 (44.7%) and 8 of 12 (66.7%) children, respectively, achieved targeted pre-dose lopinavir concentrations ≥1mg/L.

CONCLUSIONS

Modified 8-hourly dosing of lopinavir/ritonavir failed to achieve adequate lopinavir concentrations with concurrent antituberculosis treatment. The subtherapeutic lopinavir exposures on standard dosing after antituberculosis treatment are of concern and requires further evaluation.

Randomised controlled trials in child and adolescent health in 2023

In the year July 2022 to June 2023 there were 501 publications from randomised controlled trials (RCTs) in child and adolescent health in developing countries identified through a standardised search strategy that has been going for 20 years. This year, trials addressed the widest range of diseases and conditions that affect the health, development and well-being of children, newborns, adolescents and mothers. RCTs reflected old, neglected and new problems, the changing epidemiology of child health, social and economic circumstances in many countries, local and global priorities of low-income and middle-income countries, environmental causes of poor child health, and inequities. The RCTs tested new and refined treatments, diagnostics, vaccines, holistic management, and prevention approaches, and explored many outcomes, including mortality, nutrition, psychosocial measures, and neurodevelopment. The studies were conducted in numerous hospitals and healthcare clinics, schools, and communities, including among some of the world's most disadvantaged populations in humanitarian and refugee emergencies. Some studies are of the highest quality, and others fall short. Many RCTs will influence guidelines, practice and policies for years to come.

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.