Antiretroviral therapy and efficacy after virologic failure on first-line boosted protease inhibitor regimens

Virologic status and pattern of drug resistance mutation among ART-experienced HIV-infected patients in Butuo County, China

OBJECTIVES

To assess the virological outcomes, prevalence of HIV drug resistance mutation (DRM), and correlates in Butuo County.

METHODS

We conducted a cross-sectional study. Virological failure (VF) was defined as HIV-1 RNA ≥1000 copies/mL and on antiretroviral therapy (ART) for ≥6 months. Genotypic drug resistance was performed among VF cases. Correlates of DRM were identified using multivariate logistic regression.

RESULTS

The overall virological suppression rate was 85.3%; DRM was detected in 42.6% (517/1215) VF cases and 6.2% of the sample patients. A total of 90.9% of patients were infected with HIV-1 CRF07_BC subtype. The prevalence of DRM to nucleoside reverse transcriptase inhibitor (NRTI) and non-nucleoside reverse transcriptase inhibitor (NNRTI) were 46.0% and 96.9%, respectively. The most prevalent mutation for NRTI was M184V (84.5%). Lamivudine (3TC), emtricitabine (FTC), and abacavir (ABC) had the highest resistance rates. For NNRTI, K103N (60.7%), nevirapine (NVP), and efavirenz (EFV) had the highest resistance rates and cross resistance to rilpivirine (RPV), doravirine (DOR), and etravirine (ETR). Ritonavir boosted lopinavir (LPV/r) resistance rate was extremely low. The occurrence of DRM was associated with age at ART ≤18 years, baseline CD4 count ≤200 cells/mL, NVP-based regimen, and ART duration >3 years.

CONCLUSION

A relatively high proportion of VF and broad DRM for NRTI and NNRTI were observed, causing high-level resistance to first-line NRTI, NNRTI, and next generation NNRTI. Our findings necessitate the implementation of scaling up virological monitoring, adherence support, and timely switching to an LPV/r-containing regimen when patients with VF to reduce the occurrence of DRM.

A Growing Number of Men Who Have Sex With Men Aging With HIV (20212031): A Comparison of Two Microsimulation Models

BACKGROUND

Men who have sex with men (MSM) on antiretroviral therapy (ART) are at risk for multimorbidity as life expectancy increases. Simulation models can project population sizes and age distributions to assist with health policy planning.

METHODS

We populated the CEPAC-US model with CDC data to project the HIV epidemic among MSM in the United States. The PEARL model was predominantly informed by NA-ACCORD data (20092017). We compared projected population sizes and age distributions of MSM receiving ART (20212031) and investigated how parameters and assumptions affected results.

RESULTS

We projected an aging and increasing population of MSM on ART: CEPAC-US, mean age 48.6 (SD 13.7) years in 2021 versus 53.9 (SD 15.0) years in 2031; PEARL, 46.7 (SD 13.2) years versus 49.2 (SD 14.6) years. We projected 548 800 MSM on ART (147 020 65 years) in 2031 (CEPAC-US) and 599 410 (113 400 65 years) (PEARL). Compared with PEARL, CEPAC-US projected a smaller population of MSM on ART by 2031 and a slower increase in population size, driven by higher estimates of disengagement in care and mortality.

CONCLUSIONS

Findings from two structurally distinct microsimulation models suggest that the MSM population receiving ART in the United States will increase and age over the next decade. Subgroup-specific data regarding engagement in care and mortality can improve projections and inform health care policy planning.

Antiretroviral Therapy Adherence Interruptions Are Associated With Systemic Inflammation Among Ugandans Who Achieved Viral Suppression

BACKGROUND

Residual systemic inflammation, which is associated with non-AIDS clinical outcomes, may persist despite viral suppression. We assessed the effect of antiretroviral therapy (ART) adherence interruptions on systemic inflammation among Ugandans living with HIV who were virally suppressed.

SETTING

We evaluated adults initiating first-line ART at a regional referral hospital clinic in Mbarara, Uganda.

METHODS

Plasma concentrations of interleukin-6 (IL-6), D-dimer, soluble sCD14, sCD163, the kynurenine/tryptophan (K/T) ratio, and CD8 T-cell activation (HLA-DR/CD38 coexpression) were measured at baseline and 6 months after ART initiation among participants who achieved viral suppression (<400 copies/mL) at 6 months. ART adherence was monitored electronically. Time spent in an adherence interruption was computed as the percentage of days when the running average adherence was ≤10%. We fit adjusted linear regressions to evaluate the effect of time spent in an interruption on the log-transformed plasma concentrations of the inflammation biomarkers.

RESULTS

Of 282 participants, 70% were women, and the median age was 34 years. At baseline, median CD4 and median log viral load were 135 cells per microliter and 5.1 copies per milliliter, respectively. In the adjusted analysis, a running average adherence of <10% was associated with higher sCD14 (+3%; P < 0.008), sCD163 (+5%; P = 0.002), D-dimer (+10%; P = 0.007), HLA-DR/CD8 (+3%; P < 0.025), IL-6 (+14%; P = 0.008), and K:T ratio (+5%; P = 0.002). These findings were largely robust to adjustment for average adherence, as well as higher thresholds of running average adherence, albeit with decreased statistical significance.

CONCLUSIONS

Increased time spent in adherence interruptions is associated with increased levels of inflammation, despite viral suppression above and beyond average adherence.

Human Immunodeficiency Virus Type 1 Drug Resistance Mutations Update

As treatment options coalesce around a smaller number of antiretroviral drugs (ARVs), data are emerging on the drug resistance mutations (DRMs) selected by the most widely used ARVs and on the impact of these DRMs on ARV susceptibility and virological response to first- and later-line treatment regimens. Recent studies have described the DRMs that emerge in patients receiving tenofovir prodrugs, the nonnucleoside reverse transcriptase inhibitors efavirenz and rilpivirine, ritonavir-boosted lopinavir, and the integrase inhibitors raltegravir and elvitegravir. Several small studies have described DRMs that emerge in patients receiving dolutegravir.

Antiretroviral changes during the first year of therapy

INTRODUCTION

The Brazilian HIV/AIDS management and treatment guideline (PCDT), published in 2013, recommends and standardizes the use of highly active antiretroviral therapy (HAART) in all adult patients, in spite of LTCD4 count. This study aimed to analyze the first year of HAART use in patients from a reference center on HIV/AIDS management in Fortaleza, Ceará.

METHOD

This descriptive study reviewed all prescription forms of antiretroviral regimens initiation and changes from January to July 2014. All antiretroviral regimen changes that occurred during the first year of therapy were evaluated. Data were analyzed with SPSS version 20. Mean, standard deviation and frequency, Student's t and Mann-Whitney tests calculations were used, with significance at p<0.05.

RESULTS

From 527 patients initiating HAART, 16.5% (n=87) had a regimen change in the first year. These patients were mostly male (59.8%; n=52), aged 20 to 39 years, with only one HAART change (72.4%; n=63). Efavirenz was the most often changed drug, followed by tenofovir, zidovudine and lopinavir/ritonavir. Mean time of HAART changes was 120 days, with adverse reactions as the most prevalent cause. HAART was effective in decreasing viral load since second month of treatment (p=0.003) and increasing LTCD4 lymphocytes since fifth month (p<0.001).

CONCLUSION

The main cause of initial HAART changes was adverse reaction and most patients had only one change in the HAART regimen. HAART prescription was in accordance to the PCDT from 2013.

The Clinical and Economic Impact of Attaining National HIV/AIDS Strategy Treatment Targets in the United States

Background

The US National HIV/AIDS Strategy (NHAS) aims for 72% (90% diagnosed times 80% of those virally suppressed) viral suppression among persons with human immunodeficiency virus (HIV) by 2020. We examined the clinical and economic impact of reaching this target, in the general US population and among black men who have sex with men (MSM), the group with the highest HIV prevalence.

Methods

Using a mathematical simulation, we project the 5- and 20-year clinical outcomes, costs, and incremental cost-effectiveness ratios for (1) Current Pace of detection, linkage, retention, and virologic suppression and (2) NHAS investments in expanded testing ($24-$74 per test) and adherence ($400 per person-year), calibrated to achieve 72% suppression by 2020. We examined alternative rates of testing, retention, and suppression and the efficacy and cost of adherence interventions.

Results

Compared with Current Pace over 20 years, NHAS averted 280000 HIV transmissions (80000 in black MSM) and 199000 (45000) deaths and saved 2138000 (453000) years of life, while increasing costs by 23%. The incremental cost-effectiveness ratio for NHAS compared with Current Pace was $68900 per quality-adjusted life-year ($38300 for black MSM) and was most sensitive to antiretroviral therapy costs.

Conclusions

Reaching NHAS targets would yield substantial clinical benefits and be cost-effective in both the general US and black MSM populations.

Evolution of gag and gp41 in Patients Receiving Ritonavir-Boosted Protease Inhibitors

Several groups have proposed that genotypic determinants in gag and the gp41 cytoplasmic domain (gp41-CD) reduce protease inhibitor (PI) susceptibility without PI-resistance mutations in protease. However, no gag and gp41-CD mutations definitively responsible for reduced PI susceptibility have been identified in individuals with virological failure (VF) while receiving a boosted PI (PI/r)-containing regimen. To identify gag and gp41 mutations under selective PI pressure, we sequenced gag and/or gp41 in 61 individuals with VF on a PI/r (n = 40) or NNRTI (n = 20) containing regimen. We quantified nonsynonymous and synonymous changes in both genes and identified sites exhibiting signal for directional or diversifying selection. We also used published gag and gp41 polymorphism data to highlight mutations displaying a high selection index, defined as changing from a conserved to an uncommon amino acid. Many amino acid mutations developed in gag and in gp41-CD in both the PI- and NNRTI-treated groups. However, in neither gene, were there discernable differences between the two groups in overall numbers of mutations, mutations displaying evidence of diversifying or directional selection, or mutations with a high selection index. If gag and/or gp41 encode PI-resistance mutations, they may not be confined to consistent mutations at a few sites.

Treatment Outcomes and Resistance Patterns of Children and Adolescents on Second-Line Antiretroviral Therapy in Asia

BACKGROUND

Data on pediatric treatment outcomes and drug resistance while on second-line antiretroviral therapy (ART) are needed to guide HIV care in resource-limited countries.

METHODS

HIV-infected children <18 years who were switched or switching to second-line ART after first-line failure were enrolled from 8 sites in Indonesia, Thailand, and Vietnam. Genotyping was performed at virologic failure (VF; HIV-RNA >1000 copies/mL). Cox proportional hazards regression was used to evaluate factors predicting VF.

RESULTS

Of 277 children, 41% were female. At second-line switch, age was 7.5 (5.3-10.3) years, CD4 count was 300 (146-562) cells per cubic millimeter, and percentage was 13 (7-20%); HIV-RNA was 5.0 (4.4-5.5) log10 copies per milliliter. Second-line regimens contained lamivudine (90%), tenofovir (43%), zidovudine or abacavir (30%), lopinavir (LPV/r; 91%), and atazanavir (ATV; 7%). After 3.3 (1.8-5.3) years on second-line ART, CD4 was 763 (556-1060) cells per cubic millimeter and 26% (20-31%). VF occurred in 73 (27%), with an incidence of 7.25 per 100 person-years (95% confidence interval [CI]: 5.77 to 9.12). Resistance mutations in 50 of 73 children with available genotyping at first VF included M184V (56%), ≥1 thymidine analogue mutation (TAM; 40%), ≥4 TAMs (10%), Q151M (4%), any major LPV mutation (8%), ≥6 LPV mutations (2%), and any major ATV mutation (4%). Associations with VF included age >11 years (hazard ratio [HR] 4.06; 95% CI: 2.15 to 7.66) and HIV-RNA >5.0 log10 copies per milliliter (HR 2.42; 95% CI: 1.27 to 4.59) at switch and were seen more commonly in children from Vietnam (HR 2.79; 95% CI: 1.55 to 5.02).

CONCLUSIONS

One-fourth of children developed VF while on second-line ART. However, few developed major mutations to protease inhibitors.

Randomized trial of stopping or continuing ART among postpartum women with pre-ART CD4 ≥ 400 cells/mm3

Background

Health benefits of postpartum antiretroviral therapy (ART) for human immunodeficiency virus (HIV) positive women with high CD4+ T-counts have not been assessed in randomized trials.

Methods

Asymptomatic, HIV-positive, non-breastfeeding women with pre-ART CD4+ T-cell counts ≥ 400 cells/mm³ started on ART during pregnancy were randomized up to 42 days after delivery to continue or discontinue ART. Lopinavir/ritonavir plus tenofovir/emtricitabine was the preferred ART regimen. The sample size was selected to provide 88% power to detect a 50% reduction from an annualized primary event rate of 2.07%. A post-hoc analysis evaluated HIV/AIDS-related and World Health Organization (WHO) Stage 2 and 3 events. All analyses were intent to treat.

Results

1652 women from 52 sites in Argentina, Botswana, Brazil, China, Haiti, Peru, Thailand and the US were enrolled (1/2010-11/2014). Median age was 28 years and major racial categories were Black African (28%), Asian (25%) White (15%). Median entry CD4 count was 696 cells/mm³ (IQR 575–869), median ART exposure prior to delivery was 19 weeks (IQR 13–24) and 94% had entry HIV-1 RNA < 1000 copies/ml. After a median follow-up of 2.3 years, the primary composite endpoint rate was significantly lower than expected, and not significantly different between arms (continue arm 0.21 /100 person years(py); discontinue 0.31/100 py, Hazard ratio (HR) 0.68, 95% CI: 0.19, 2.40). WHO Stage 2 and 3 events were significantly reduced with continued ART (2.08/100 py vs. 4.36/100 py in the discontinue arm; HR 0.48, 95%CI: 0.33, 0.70). Toxicity rates did not differ significantly between arms. Among women randomized to continue ART, 189/827 (23%) had virologic failure; of the 155 with resistance testing, 103 (66%) failed without resistance to their current regimen, suggesting non-adherence.

Conclusions

Overall, serious clinical events were rare among young HIV-positive post-partum women with high CD4 cell counts. Continued ART was safe and was associated with a halving of the rate of WHO 2/3 conditions. Virologic failure rates were high, underscoring the urgent need to improve adherence in this population.

Trial registration

ClinicalTrials.gov NCT00955968

HIV-1 drug resistance and resistance testing

The global scale-up of antiretroviral (ARV) therapy (ART) has led to dramatic reductions in HIV-1 mortality and incidence. However, HIV drug resistance (HIVDR) poses a potential threat to the long-term success of ART and is emerging as a threat to the elimination of AIDS as a public health problem by 2030. In this review we describe the genetic mechanisms, epidemiology, and management of HIVDR at both individual and population levels across diverse economic and geographic settings. To describe the genetic mechanisms of HIVDR, we review the genetic barriers to resistance for the most commonly used ARVs and describe the extent of cross-resistance between them. To describe the epidemiology of HIVDR, we summarize the prevalence and patterns of transmitted drug resistance (TDR) and acquired drug resistance (ADR) in both high-income and low- and middle-income countries (LMICs). We also review to two categories of HIVDR with important public health relevance: (i) pre-treatment drug resistance (PDR), a World Health Organization-recommended HIVDR surveillance metric and (ii) and pre-exposure prophylaxis (PrEP)-related drug resistance, a type of ADR that can impact clinical outcomes if present at the time of treatment initiation. To summarize the implications of HIVDR for patient management, we review the role of genotypic resistance testing and treatment practices in both high-income and LMIC settings. In high-income countries where drug resistance testing is part of routine care, such an understanding can help clinicians prevent virological failure and accumulation of further HIVDR on an individual level by selecting the most efficacious regimens for their patients. Although there is reduced access to diagnostic testing and to many ARVs in LMIC, understanding the scientific basis and clinical implications of HIVDR is useful in all regions in order to shape appropriate surveillance, inform treatment algorithms, and manage difficult cases.

Outcomes after viral load rebound on first-line antiretroviraltreatment in children with HIV in the UK and Ireland: an observational cohort study

BACKGROUND

About a third of children with HIV have virological failure within 2 years of beginning antiretroviral treatment (ART). We assessed the probability of switch to second-line ART or virological re-suppression without switch in children who had virological rebound on first-line ART in the UK and Ireland.

METHODS

In this study, we used data reported to the Collaborative HIV Paediatric Study (CHIPS), a national multicentre observational cohort. We included children with virological rebound (confirmed viral load>400 copies per mL after suppression<400 copies per mL) on first-line ART. We did a competing-risk analysis to estimate the probability of switch to second-line treatment, confirmed resuppression (two consecutive viral load measurments<400 copies per mL) without switch, and continued viral load above 400 copies per mL without switch. We also assessed factors that predicted a faster time to switch.

FINDINGS

Of the 900 children starting first-line ART who had a viral load below 400 copies per mL within a year of starting treatment, 170 (19%) had virological rebound by a median of 20·6 months (IQR 9·7–40·5). At rebound, median age was 10·6 years (5·6–13·4), median viral load was 3·6 log10 copies per mL (3·1–4·2), and median CD4% was 24% (17–32). 89 patients (52%) switched to second-line ART at a median of 4·9 months (1·7–13·4) after virological rebound, 53 (31%) resuppressed without switch (19 [61%] of 31 patients on a first-line regimen that included a protease inhibitor and 31 [24%] of 127 patients on a first-line regimen that included a non-nucleoside reverse transcriptase inhibitor; NNRTI), and 28 (16%) neither resuppressed nor switched. At 12 months after rebound, the estimated probability of switch was 38% (95% CI 30–45) and of resuppression was 27% (21–34). Faster time to switch was associated with a higher viral load (p<0·0001), later calendar year at virological rebound (p=0·02), and being on an NNRTI-based or triple nucleoside reverse transcriptase inhibitor-based versus protease-inhibitor-based first-line regimen (p=0·001).

INTERPRETATION

A third of children with virological rebound resuppressed without switch. Clinicians should consider the possibility of resuppression with adherence support before switching treatment in children with HIV.

FUNDING

NHS England (London Specialised Commissioning Group).

HIV-1 Drug Resistance Mutations: Potential Applications for Point-of-Care Genotypic Resistance Testing

The increasing prevalence of acquired and transmitted HIV-1 drug resistance is an obstacle to successful antiretroviral therapy (ART) in the low- and middle-income countries (LMICs) hardest hit by the HIV-1 pandemic. Genotypic drug resistance testing could facilitate the choice of initial ART in areas with rising transmitted drug resistance (TDR) and enable care-providers to determine which individuals with virological failure (VF) on a first- or second-line ART regimen require a change in treatment. An inexpensive near point-of-care (POC) genotypic resistance test would be useful in settings where the resources, capacity, and infrastructure to perform standard genotypic drug resistance testing are limited. Such a test would be particularly useful in conjunction with the POC HIV-1 viral load tests that are currently being introduced in LMICs. A POC genotypic resistance test is likely to involve the use of allele-specific point mutation assays for detecting drug-resistance mutations (DRMs). This study proposes that two major nucleoside reverse transcriptase inhibitor (NRTI)-associated DRMs (M184V and K65R) and four major NNRTI-associated DRMs (K103N, Y181C, G190A, and V106M) would be the most useful for POC genotypic resistance testing in LMIC settings. One or more of these six DRMs was present in 61.2% of analyzed virus sequences from ART-naïve individuals with intermediate or high-level TDR and 98.8% of analyzed virus sequences from individuals on a first-line NRTI/NNRTI-containing regimen with intermediate or high-level acquired drug resistance. The detection of one or more of these DRMs in an ART-naïve individual or in a individual with VF on a first-line NRTI/NNRTI-containing regimen may be considered an indication for a protease inhibitor (PI)-containing regimen or closer virological monitoring based on cost-effectiveness or country policy.

Antiretroviral therapy: treatment-experienced individuals

Antiretroviral therapy (ART)-experienced individuals may choose to modify their regimens because of suboptimal virologic response, poor tolerability, convenience, or to minimize interactions with other medications or food. Constructing a new regimen for any of these reasons requires a thorough review of prior antiretroviral drug use and available drug resistance results. This article summarizes the strategies used in managing the ART-experienced individual who is considering a modification in therapy at the time of suboptimal virologic response or while virologically suppressed on a stable regimen.