Virological outcomes and genotypic resistance on dolutegravir-based antiretroviral therapy versus standard of care in children and adolescents: a secondary analysis of the ODYSSEY trial

BACKGROUND

ODYSSEY showed superior efficacy for dolutegravir-based antiretroviral therapy (ART) versus standard of care (SOC) in children living with HIV starting first-line or second-line ART aged 4 weeks or older. Here, we aim to compare virological outcomes and resistance in the dolutegravir group versus SOC for first-line and second-line ART up to 96 weeks.

METHODS

ODYSSEY was an open-label, multicentre, randomised, non-inferiority trial done in 29 centres in seven countries (Germany, Spain, South Africa, Thailand, the UK, Uganda, and Zimbabwe). ODYSSEY recruited children living with HIV aged at least 28 days and younger than 18 years, weighing at least 3 kg, starting first-line ART (ODYSSEY A), or switching to second-line therapy after treatment failure (ODYSSEY B). Children were randomly assigned (1:1) to dolutegravir plus two nucleoside or nucleotide reverse transcriptase inhibitors (NRTIs; dolutegravir group) versus the SOC group (non-nucleoside reverse transcriptase inhibitor [NNRTI], boosted protease inhibitor, or non-dolutegravir integrase strand-transfer inhibitor, plus two NRTIs). Two randomised cohorts were combined in this exploratory analysis: children weighing at least 14 kg were enrolled between Sept 20, 2016, and June 22, 2018, and children weighing less than 14 kg were enrolled between July 5, 2018, and Aug 26, 2019. Virological failure was defined as an inadequate virological response at week 24 with an ART switch or confirmed HIV-1 RNA viral load of at least 400 copies per mL after week 36. Virological suppression was defined as two consecutive viral loads of less than 400 copies per mL and was compared between groups, including an ART switch and death as competing risks. Children with virological failure were tested for post-failure genotypic resistance, with baseline results used to identify emergent resistance. Development of emergent resistance was a secondary trial outcome and all other outcomes are exploratory. ODYSSEY was registered with ClinicalTrials.gov (NCT02259127), EUDRACT (2014-002632-14), and ISRCTN (ISRCTN91737921).

FINDINGS

In ODYSSEY at enrolment, 381 participants started first-line ART (ODYSSEY A: 189 in the dolutegravir group and 192 in the SOC group) and 407 participants started second-line ART (ODYSSEY B: 202 in the dolutegravir group and 205 in the SOC group). 72 participants in ODYSSEY A and 13 participants in ODYSSEY B weighed less than 14 kg. 401 (51%) of 788 participants were female and 387 (49%) were male. Virological suppression occurred significantly earlier in the dolutegravir group (adjusted [cause-specific] hazard ratio [HR] 1·57 [95% CI 1·35 to 1·83]; p<0·0001). Overall, 51 (13%) participants had virological failure by 96 weeks in the dolutegravir group versus 86 (22%) in the SOC group (including 18 [10%] vs 43 [22%] in ODYSSEY A and in 33 [16%] vs 43 [21%] in ODYSSEY B; adjusted HR 0·56 [0·40 to 0·79]; p=0·0011). Among ODYSSEY B participants starting dolutegravir, virological failure was higher in children starting zidovudine (HR 2·22 [1·01 to 4·88]; p=0·048) and similar in those starting tenofovir disoproxil fumarate (1·19 [0·50 to 2·83]; p=0·70) compared with abacavir. Time to virological suppression was marginally faster in participants receiving second-line dolutegravir and abacavir with high-level abacavir resistance at baseline compared with those with no, low-level, intermediate-level resistance (cause-specific HR 1·70 [1·01 to 2·85]; p=0·046); and failure rates by week 96 were similar (HR 0·90 [0·23 to 3·61]; p=0·88). An estimated 1% (95% CI 0 to 2) of participants in the dolutegravir group versus 20% (14 to 26) in the SOC group in ODYSSEY A had emergent resistance to at least one drug-class within their first-line regimen (risk difference -20% [-25 to -14]; p<0·0001); 4% (1 to 6) versus 5% (2 to 8) had resistance to drug within their initial second-line regimen (risk difference -1% [-5 to 3]; p=0·60). 3% (0 to 5) of participants in the dolutegravir group had emergent integrase strand-transfer inhibitors resistance compared with 3% (1 to 6) of participants in the SOC group who had emergent resistance to the anchor drug (risk difference 0% [-4 to 3]; p=0·78).

INTERPRETATION

Dolutegravir led to faster virological suppression and lower risk of virological failure than NNRTIs and boosted protease inhibitor-based SOC. Participants starting second-line dolutegravir-based ART with an abacavir or tenofovir backbone were at lower risk of virological failure than those starting zidovudine. During first-line therapy, dolutegravir protected against emergent resistance; starting second-line therapy, the risk of emergent resistance to nucleoside reverse transcriptase inhibitor backbone, and anchor drugs, was similar among participants starting dolutegravir within their second-line regimen and those starting mainly boosted protease inhibitor-based SOC.

FUNDING

Penta Foundation, ViiV Healthcare, and UK Medical Research Council.

Global, regional, and national prevalence of HIV-1 drug resistance in treatment-naive and treatment-experienced children and adolescents: a systematic review and meta-analysis

Background

Despite significant reductions in mother-to-child HIV-1 transmission risks due to the advancements and scale-up of antiretroviral therapy (ART), the global burden of HIV-1 drug resistance (HIVDR) in treatment-naive and treatment-experienced children and adolescents remains poorly understood. In this study, we conducted a systematic review and meta-analysis to estimate the prevalence of HIVDR in these populations globally, regionally, and at the country level.

Methods

We systematically searched PubMed, Embase, and Web of Science for studies reporting HIVDR in treatment-naive and treatment-experienced children and adolescents from inception to June 28, 2024. Eligible studies reported at least ten successfully genotyped cases. We excluded studies where drug resistance was not reported separately for children and adults or for treatment-naive and treatment-experienced populations. The methodological quality of eligible studies was assessed, and random-effect models were used for meta-analysis to determine the pooled overall and regimen-specific prevalence of one or more HIVDR mutations in these populations globally, regionally, or at the country level. This study is registered with PROSPERO under the number CRD42023424483.

Findings

Of 2282 records identified, 136 studies (28,539 HIV-1-infected children from 52 countries) were included for analysis. The overall prevalence of HIVDR is 26.31% (95% CI, 20.76-32.25) among treatment-naive children and 74.16% (95% CI, 67.74-80.13) among treatment-experienced children (p < 0.0001). HIVDR varied widely across subregion with the highest prevalence in Southern Africa (37.80% [95% CI, 26.24-50.08]) and lowest in South America (11.79% [95% CI, 4.91-20.84]) for treatment-naive children while highest in Asia (80.85% [95% CI, 63.76-93.55]) and lowest in Europe (54.39% [95% CI, 28.61-79.03]) for treatment-experienced children. The proportion of viral failure (VF) presented positive correlation with DR prevalence for treatment-experienced children, which increased from 61.23% (95% CI, 47.98-73.72) in proportion of VF <50%-81.17% (95% CI, 71.57-89.28) in proportion of 100%. Meta-regression analysis for both groups showed that only age (naive: p = 0.0005; treated: p < 0.0001) was the sources of heterogeneity. Non-nucleoside reverse transcriptase inhibitor (NNRTI) resistances were the most seen mutations among the treatment-naive group, with the HIVDR prevalence more than 10% in Southern Africa, Western and Central Africa, Eastern Africa, Asia, and North America. Both nucleoside reverse transcriptase inhibitor (NRTI) and NNRTI resistances were commonly seen among the treatment-experienced group, varying from 36.33% (95% CI, 11.96-64.93) in North America to 77.54% (95% CI, 62.70-89.58) in South America for NRTI and from 39.98% (95% CI, 13.47-69.97) in Europe to 68.86 (95% CI, 43.91-89.17) in Asia for NNRTI, respectively.

Interpretation

This study underscores the significant burden of HIVDR among children and adolescents worldwide, particularly pronounced in sub-Saharan Africa and low-income countries. It emphasizes the critical importance of surveillance in all HIV-1-infected children and advocates for the adoption of dolutegravir (DTG) or other optimal formulations as first-line ART in settings where NNRTI resistance exceeds the WHO's 10% threshold. DTG's high resistance barrier, potent antiviral efficacy, and favorable safety profile makes it a superior choice for managing drug-resistant HIV-1, surpassing traditional antiretroviral therapies.

Funding

This work was supported by the Science and Technology Innovation Committee of Shenzhen Municipality (No. JCYJ20220531102202005) and the Natural Science Foundation of Guangdong Province (No. 2024A1515012118).

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

BACKGROUND

The PENPACT-1 trial compared virologic thresholds to determine when to switch to second-line antiretroviral therapy (ART). Using PENPACT-1 data, we aimed to describe HIV-1 drug resistance accumulation on first-line ART by virologic threshold.

METHODS

PENPACT-1 had a 2 × 2 factorial design, randomizing HIV-infected children to start protease inhibitor (PI) versus nonnucleoside reverse transcriptase inhibitor (NNRTI)-based ART, and switch at a 1000 copies/mL versus 30,000 copies/mL threshold. Switch criteria were not achieving the threshold by week 24, confirmed rebound above the threshold thereafter, or Center for Disease Control and Prevention stage C event. Resistance tests were performed on samples ≥1000 copies/mL before switch, resuppression, and at 4-years/trial end.

RESULTS

Sixty-seven children started PI-based ART and were randomized to switch at 1000 copies/mL (PI-1000), 64 PIs and 30,000 copies/mL (PI-30,000), 67 NNRTIs and 1000 copies/mL (NNRTI-1000), and 65 NNRTI and 30,000 copies/mL (NNRTI-30,000). Ninety-four (36%) children reached the 1000 copies/mL switch criteria during 5-year follow-up. In 30,000 copies/mL threshold arms, median time from 1000 to 30,000 copies/mL switch criteria was 58 (PI) versus 80 (NNRTI) weeks (P = 0.81). In NNRTI-30,000, more nucleoside reverse transcriptase inhibitor (NRTI) resistance mutations accumulated than other groups. NNRTI mutations were selected before switching at 1000 copies/mL (23% NNRTI-1000, 27% NNRTI-30,000). Sixty-two children started abacavir + lamivudine, 166 lamivudine + zidovudine or stavudine, and 35 other NRTIs. The abacavir + lamivudine group acquired fewest NRTI mutations. Of 60 switched to second-line, 79% PI-1000, 63% PI-30,000, 64% NNRTI-1000, and 100% NNRTI-30,000 were <400 copies/mL 24 weeks later.

CONCLUSIONS

Children on first-line NNRTI-based ART who were randomized to switch at a higher virologic threshold developed the most resistance, yet resuppressed on second-line. An abacavir + lamivudine NRTI combination seemed protective against development of NRTI resistance.

Paediatric European Network for Treatment of AIDS (PENTA) guidelines for treatment of paediatric HIV-1 infection 2015: optimizing health in preparation for adult life

The 2015 Paediatric European Network for Treatment of AIDS (PENTA) guidelines provide practical recommendations on the management of HIV‐1 infection in children in Europe and are an update to those published in 2009. Aims of treatment have progressed significantly over the last decade, moving far beyond limitation of short‐term morbidity and mortality to optimizing health status for adult life and minimizing the impact of chronic HIV infection on immune system development and health in general. Additionally, there is a greater need for increased awareness and minimization of long‐term drug toxicity. The main updates to the previous guidelines include: an increase in the number of indications for antiretroviral therapy (ART) at all ages (higher CD4 thresholds for consideration of ART initiation and additional clinical indications), revised guidance on first‐ and second‐line ART recommendations, including more recently available drug classes, expanded guidance on management of coinfections (including tuberculosis, hepatitis B and hepatitis C) and additional emphasis on the needs of adolescents as they approach transition to adult services. There is a new section on the current ART ‘pipeline’ of drug development, a comprehensive summary table of currently recommended ART with dosing recommendations. Differences between PENTA and current US and World Health Organization guidelines are highlighted and explained.

Durability of antiretroviral therapy and predictors of virologic failure among perinatally HIV-infected children in Tanzania: a four-year follow-up

BACKGROUND

In Tanzania, HIV-1 RNA testing is rarely available and not standard of care. Determining virologic failure is challenging and resistance mutations accumulate, thereby compromising second-line therapy. We evaluated durability of antiretroviral therapy (ART) and predictors of virologic failure among a pediatric cohort at four-year follow-up.

METHODS

This was a prospective cross-sectional study with retrospective chart review evaluating a perinatally HIV-infected Tanzanian cohort enrolled in 2008-09 with repeat HIV-1 RNA in 2012-13. Demographic, clinical, and laboratory data were extracted from charts, resistance mutations from 2008-9 were analyzed, and prospective HIV RNA was obtained.

RESULTS

161 (78%) participants of the original cohort consented to repeat HIV RNA. The average age was 12.2 years (55% adolescents ≥12 years). Average time on ART was 6.4 years with 41% receiving second-line (protease inhibitor based) therapy. Among those originally suppressed on a first-line (non-nucleoside reverse transcriptase based regimen) 76% remained suppressed. Of those originally failing first-line, 88% were switched to second-line and 72% have suppressed virus. Increased level of viremia and duration of ART trended with an increased number of thymidine analogue mutations (TAMs). Increased TAMs increased the odds of virologic failure (p = 0.18), as did adolescent age (p < 0.01).

CONCLUSIONS

After viral load testing in 2008-09 many participants switched to second-line therapy. The majority achieved virologic suppression despite multiple resistance mutations. Though virologic testing would likely hasten the switch to second-line among those failing, methods to improve adherence is critical to maximize durability of ART and improve virologic outcomes among youth in resource-limited settings.