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.

Thai national guidelines for the use of antiretroviral therapy in pediatric HIV infection in 2010

With better knowledge and availability of antiretroviral treatments, the Thai National HIV Guidelines Working Group has issued treatment guidelines for children in Thailand in March 2010. The most important aspects of these new guidelines are detailed below. ART should be initiated in infants less than 12 months of age at any CD4 level regardless of symptoms and in all children at CDC clinical stage B and C or WHO clinical stages 3 and 4. For children with no or mild symptoms consider CD4-guided thresholds of CD4 <25% (children aged one to five years) or CD4 <350 cells/mm3 (children 5 years or older). The preferred first-line regimen in children aged < 3 years is AZT+3TC+NVP. For children >3 years of age the preferred regimen is AZT+3TC+EFV. If an infant has previously been exposed to NVP perinatally, use AZT+3TC+LPV/r as empirical first regimen. In adolescents, consider TDF+3TC+EFV. The preferred ARV treatment in children who failed first line regimens of 2NRTI+NNRTI (Salvage treatment) comprises 2NRTI (guided by genotype) +LPV/r, and an alternative regimen is 2NRTI (guided by genotype) +ATV/ r (use in cases with dyslipidemia who are six years or older). In cases with extensive NRTI resistance with no effective NRTI option available, double boosted PI with LPV/r+SQV or LPV/r+IDV can be considered. Consultation with an expert is recommended. Laboratory monitoring is recommended for CD4 and every six months. Viral load at least at 6 and 12 months after initiation or change of regimen, then yearly thereafter. More frequent viral load monitoring is advised for cases with unsuccessful virologic response, infants, children with imperfect adherence, or those using of third line regimens. Toxicity monitoring depends on the drug received, at least every six months, and more often as clinically indicated. These include, but are not limited to, complete blood count, renal function tests, liver function tests, urinanalysis, and lipid profiles. Therapeutic drug monitoring is recommended in cases that have ARV-related toxicity, receiving non-standard dosing or regimens, using double boosted PI, and in those with renal or hepatic impairment.

Second- and Third-line Antiretroviral Therapy for Children and Adolescents: A Scoping Review

BACKGROUND

The World Health Organization identified a need for evidence to inform revision of second- and third-line antiretroviral therapy (ART) options in children failing ART. We performed an in-depth scoping review of all available literature on second-line and subsequent ART regimens in children younger than 18 years.

METHODS

We comprehensively searched, without language or date limitations, the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, the World Health Organization's International Clinical Trials Registry Platform and ClinicalTrials.gov.

RESULTS

The search retrieved 1982 records. Eighteen studies provided efficacy data: 1 randomized controlled trial, 7 phase II trials, 5 prospective and 5 retrospective cohorts. Five studies evaluated regimens in children failing first-line ART, 4 in children with multidrug resistance and 9 in children with variable treatment experience. Only 10/18 studies reported week 48 or month 12 outcomes. The overall proportion of children with virologic suppression defined by study at week 48 was 61.8%. Although the randomized controlled trial had low risk of bias, outcomes were similar between groups because of highly active optimized background regimens. All phase II and prospective studies were judged to have moderate to high risk of bias. No study compared currently recommended lopinavir-based second-line regimens for nonnucleoside reverse transcriptase inhibitor failures to other non-nonnucleoside reverse transcriptase inhibitor regimens head-to-head.

CONCLUSIONS

We found no evidence comparing current World Health Organization-recommended second- and third-line ART regimens with regimens including drugs of interest: raltegravir, darunavir, etravirine and atazanavir. Randomized controlled trials or prospective cohort studies with comparator arms, and bridging studies, ideally conducted in resource-limited settings, are required to guide future recommendations.

Therapeutic Drug Monitoring of Lopinavir in HIV-Infected Children on Second-Line Antiretroviral Therapy in Asia

BACKGROUND

Failure rates of second-line boosted protease inhibitor antiretroviral therapy regimens in children rise over time. Therapeutic drug monitoring can contribute to assessments of adherence. The authors assessed the performance characteristics of the US DHHS-recommended lopinavir (LPV) concentration of 1.0 mg/L for predicting virologic failure (VF) and intermediate- to high-level LPV resistance in Asian children.

METHODS

LPV concentration, HIV RNA level, and adherence data from study participants in Thailand, Vietnam, and Indonesia receiving second-line LPV-based ART and followed for ≥24 weeks were analyzed.

RESULTS

A total of 223 children at a median age of 10.4 (interquartile range, 7.9-13.4) years were enrolled, and 61% of them were male. Their mean CD4 was 842 ± 438 cells per cubic millimeter, and the median LPV duration was 2.5 (interquartile range, 1.3-4.2) years. Five of 84 (6%) and 18 of 139 (13%) children had LPV trough and random concentrations <1.0 mg/L at study week 24. Using either of these trough or random LPV concentrations, a cutoff at 1.0 mg/L gave an area under the receiver operating characteristics curve of 0.69 in predicting VF with sensitivity of 44% (95% CI 23-66) and specificity of 94% (95% CI 89-97). Seven of 21 with VF and resistance results available had ≥1 major protease inhibitor mutation. Multivariate logistic regression found LPV concentrations <1.0 mg/L (odds ratio, 6.47; 95% CI 2.15-19.50, P = 0.001) and CD4 ≤20% (odds ratio, 2.83; 95% CI 1.01-7.89, P = 0.05) were independently associated with HIV RNA >1000 copies per milliliter. No factors predicted major LPV resistance mutations.

CONCLUSIONS

The authors support that the DHHS target LPV concentration of <1.0 mg/L is predictive of VF, but not of the presence of major LPV mutations.

HIV protease inhibitors in pulmonary hypertension: rationale and design of a pilot trial in idiopathic pulmonary arterial hypertension

We propose an exploratory clinical study, the first of its kind to our knowledge, to determine the safety and potential clinical benefit of the combination of the HIV protease inhibitors (HIV-PIs) saquinavir and ritonavir (SQV+RIT) in patients with idiopathic pulmonary arterial hypertension (IPAH). This study is based on evidence that (1) HIV-PIs can improve pulmonary hemodynamics in experimental models; (2) both Toll-like receptor 4 and high-mobility group box 1 (HMGB1) participate in the pathogenesis of experimental pulmonary hypertension; and (3) a high-throughput screen for inhibitors of HMGB1-induced macrophage activation yielded HIV-PIs as potent inhibitors of HMGB1-induced cytokine production. In this proposed open-label, pre-post study, micro, low, and standard doses of SQV+RIT will be given to IPAH patients for 14 days. Patients will receive follow-up for the next 14 days. The primary outcome to be evaluated is change in HMGB1 level from baseline at 14 days. The secondary outcome is changes in tumor necrosis factor α, interleukin 1β, interleukin 6, C-reactive protein, pulmonary arterial pressure based on echocardiography parameters and New York Heart Association/World Health Organization functional class, and Brog dyspnea scale index from baseline at 14 days. Other secondary measurements will include N-terminal pro-brain natriuretic peptide, atrial natriuretic peptide, and 6-minute walk distance. We propose that SQV+RIT treatment will improve inflammatory disorders and pulmonary hemodynamics in IPAH patients. If the data support a potentially useful therapeutic effect and suggest that SQV+RIT is safe in IPAH patients, the study will warrant further investigation. (ClinicalTrials.gov identifier: NCT02023450.).

Treatment Failure in HIV-Infected Children on Second-line Protease Inhibitor-Based Antiretroviral Therapy

BACKGROUND

Human immunodeficiency virus (HIV)-infected children failing second-line antiretroviral therapy (ART) have no access to third-line antiretroviral drugs in many resource-limited settings. It is important to identify risk factors for second-line regimen failure.

METHODS

HIV-infected children initiating protease inhibitor (PI)-containing second-line ART within the Program for HIV Prevention and Treatment observational cohort study in Thailand between 2002 and 2010 were included. Treatment failure was defined as confirmed HIV type 1 RNA load >400 copies/mL after at least 6 months on second-line regimen or death. Adherence was assessed by drug plasma levels and patient self-report. Cox proportional hazards regression analyses were used to identify risk factors for failure.

RESULTS

A total of 111 children started a PI-based second-line regimen, including 59 girls (53%). Median first-line ART duration was 1.9 years (interquartile range [IQR], 1.4-3.3 years), and median age at second-line initiation was 10.7 years (IQR, 6.3-13.4 years). Fifty-four children (49%) experienced virologic failure, and 2 (2%) died. The risk of treatment failure 24 months after second-line initiation was 41%. In multivariate analyses, failure was independently associated with exposure to first-line ART for >2 years (adjusted hazard ratio [aHR], 1.8; P = .03), age >13 years (aHR, 2.9; P < .001), body mass index-for-age z score < -2 standard deviations at second-line initiation (aHR, 2.8; P = .03), and undetectable drug levels within 6 months following second-line initiation (aHR, 4.5; P < .001).

CONCLUSIONS

Children with longer exposure to first-line ART, entry to adolescence, underweight, and/or undetectable drug levels were at higher risk of failing second-line ART and thus should be closely monitored.