Virological Outcomes of Second-line Protease Inhibitor-Based Treatment for Human Immunodeficiency Virus Type 1 in a High-Prevalence Rural South African Setting: A Competing-Risks Prospective Cohort Analysis

Time to Treatment Failure and Its Predictors Among Second-Line ART Clients in Amhara Region, Ethiopia: A Retrospective Follow-Up Study

Background

Second-line antiretroviral treatment failure has become a major public health issue, and the time to treatment failure among second-line ART clients varies globally, and the Sub-Saharan African region having a high rate of second-line ART treatment failures. In addition, after the ART treatment guideline changed there is limited information on Ethiopia. Therefore, this study aimed to assess time to treatment failure and its determinants among second-line ART clients in Amhara Region, Ethiopia.

Methods

A multi-centered retrospective follow-up study was conducted. A random sample of 860 people on second-line ART was selected by using a computer-generated simple random sampling technique from January 30, 2016, to January 30, 2021, at the University of Gondar Compressive Specialized Hospital, Felege Hiwot Compressive Specialized Referral Hospital, and Debre Tabor Compressive Specialized Referral Hospital, in Amhara region, Ethiopia. Data was captured using a checklist.

Results

A total of 81 (9.4%) ART clients developed second-line treatment failure, with a median follow-up time of 29 months with an interquartile range (IQR: 18, 41]. The risk of second-line treatment failure is higher among patients aged 15 to 30 years (adjusted hazard ratio (AHR) = 2.01, 95% confidence interval (CI): [1.16, 3.48]). Being unable to read and write (AHR = 1.312, 95% CI: [1.068, 1.613]), and poor ART drug adherence (AHR = 3.067, 95% CI: [1.845, 5.099]) were significant predictors of second-line ART treatment failures.

Conclusion

In the current study, the time to second-line ART treatment failure was high compared with a previous similar study in Ethiopia. Factors like being younger age, ART clients who are not being able to read and write, and having poor ART drug adherence was significant predictors of second-line ART treatment failure.

Limited emergence of resistance to integrase strand transfer inhibitors (INSTIs) in ART-experienced participants failing dolutegravir-based antiretroviral therapy: a cross-sectional analysis of a Northeast Nigerian cohort

BACKGROUND

Due to the high prevalence of resistance to NNRTI-based ART since 2018, consolidated recommendations from the WHO have indicated dolutegravir as the preferred drug of choice for HIV treatment globally. There is a paucity of resistance outcome data from HIV-1 non-B subtypes circulating across West Africa.

AIMS

We characterized the mutational profiles of persons living with HIV from a cross-sectional cohort in North-East Nigeria failing a dolutegravir-based ART regimen.

METHODS

WGS of plasma samples collected from 61 HIV-1-infected participants following virological failure of dolutegravir-based ART were sequenced using the Illumina platform. Sequencing was successfully completed for samples from 55 participants. Following quality control, 33 full genomes were analysed from participants with a median age of 40 years and median time on ART of 9 years. HIV-1 subtyping was performed using SNAPPy.

RESULTS

Most participants had mutational profiles reflective of exposure to previous first- and second-line ART regimens comprised NRTIs and NNRTIs. More than half of participants had one or more drug resistance-associated mutations (DRMs) affecting susceptibility to NRTIs (17/33; 52%) and NNRTIs (24/33; 73%). Almost a quarter of participants (8/33; 24.4%) had one or more DRMs affecting tenofovir susceptibility. Only one participant, infected with HIV-1 subtype G, had evidence of DRMs affecting dolutegravir susceptibility-this was characterized by the T66A, G118R, E138K and R263K mutations.

CONCLUSIONS

This study found a low prevalence of resistance to dolutegravir; the data are therefore supportive of the continual rollout of dolutegravir as the primary first-line regimen for ART-naive participants and the preferred switch to second-line ART across the region. However, population-level, longer-term data collection on dolutegravir outcomes are required to further guide implementation and policy action across the region.

Second-Line Antiretroviral Treatment Outcome in HIV-Infected Patients Coinfected with Tuberculosis in Pakistan

Background

Tuberculosis (TB) coinfection in human immunodeficiency virus- (HIV-) infected patients is considered a risk of antiretroviral therapy (ART) failure. Coadministration of antitubercular therapy (ATT) with ART is another challenge for TB management.

Objective

The study was aimed at investigating contributing factors affecting treatment outcomes in HIV-/TB-coinfected patients.

Design

Cross-sectional. Setting. Samples were collected from the Pakistan Institute of Medical Sciences Hospital Islamabad. Subject and Methods. Clinicodemographic and immunovirological factors between the two groups were compared. The Student t-test and chi-square test were applied to compare outcome variables, and logistic regression was applied to determine the effect of TB on virological failure (VF). Main Outcome Measures. TB coinfection did not increase VF even in univariate (p = 0.974) and multivariate analysis at 6 and 12 months of 2^nd-line ART start. ARV switching was significant (p = 0.033) in TB-coinfected patients. VF was significantly high in ATT-coadministered patients along with a viral load of ≥1000 (p = 0.000). Sample Size and Characteristics. We recruited seventy-four HIV patients on 2^nd-line ART; 33 coinfected with TB were followed for at least 12 months.

Conclusion

In HIV-/TB-coinfected patients, CD4 count, CD4 gain, and VF remained comparable to HIV patients with no TB infection. ATT significantly affects the treatment outcome, suggesting drug-to-drug interactions. These factors are important to revisit the therapeutic guidelines to maximize the benefit of dual therapy in resource-limited settings.

Treatment Outcomes After Switching to Second-Line Anti-Retroviral Therapy: Results From the Thai National Treatment Program

This study aimed to assess second-line antiretroviral therapy (ART) outcomes in a National HIV Treatment program. People living with HIV aged ≥18 years initiating first-line ART who switched to second-line protease inhibitor-based regimens from January 2008 to May 2019, with a minimum of 1-year follow-up were studied. The primary outcome was second-line treatment failure (two consecutive virological failure episodes (viral load ≥1000 copies/mL)). Of 318,506 PLH initiating ART, 29,015 (9.1%) switched to second-line regimens after a median (IQR) ART duration of 1.63 (0.60-3.59) years. Lost to follow-up (LTFU) occurred in 5316 (18.3%) of whom 1376 (5%) remained LTFU and alive; 4606 (15.9%) died. Cumulative second-line failure incidence was 9.8% at 6 years, more common in females, younger PLH those with lower switch CD4 cell counts. Multidisciplinary, innovative support systems are needed to improve second-line treatment outcomes, particularly those relating to modifiable risk factors.

Virological failure among people living with HIV receiving second-line antiretroviral therapy in Pune, India

BACKGROUND

The number of people receiving second-line antiretroviral therapy (ART) has increased as global access to ART has expanded. Data on the burden and factors associated with second-line ART virologic failure (VF) from India remain limited.

METHODS

We conducted cross-sectional viral load (VL) testing among adults (≥ 18 years) who were registered at a publicly funded ART center in western India between 2014 and 2015 and had received second-line ART for at least 6 months. Sociodemographic and clinical characteristics were abstracted from routinely collected programmatic data. Logistic regression evaluated factors associated with VF (defined as VL > 1000 copies/mL).

RESULTS

Among 400 participants, median age was 40 years (IQR 34-44), 71% (285/400) were male, and 15% (59/400) had VF. Relative to participants without VF, those with VF had lower median CD4 counts (230 vs 406 cells/mm³, p < 0.0001), lower weight at first-line failure (49 vs 52 kg, p = 0.003), were more likely to have an opportunistic infection (17% vs 3%, p < 0.0001) and less likely to have optimal ART adherence (71% vs 87%, p = 0.005). In multivariable analysis, VF was associated with opportunistic infection (aOR, 4.84; 95% CI, 1.77-13.24), lower CD4 count (aOR 4.15; 95% CI, 1.98-8.71) and lower weight at first-line failure (aOR, 2.67; 95% CI, 1.33-5.34).

CONCLUSIONS

We found second-line VF in about a sixth of participants in our setting, which was associated with nearly fivefold increased odds in the context of opportunistic infection. Weight could be a useful clinical indicator for second-line VF.

Joint Modeling of Incidence of Unfavorable Outcomes and Change in Viral Load Over Time Among Adult HIV/AIDS Patients on Second-Line Anti-Retroviral Therapy, in Selected Public Hospitals of Addis Ababa, Ethiopia

Background

In Ethiopia, second-line anti-retroviral therapy (ART) for HIV/AIDS patients was started some years ago; however, few studies have reported the unfavorable outcomes of second-line ART. Therefore, this study aimed to assess the incidence and predictors of unfavorable outcomes and their association with change in viral load among adult HIV/AIDS patients on second-line treatment at selected public hospitals in Addis Ababa, Ethiopia.

Methods

A retrospective follow-up study was conducted at selected public hospitals in Addis Ababa, Ethiopia, on 421 HIV/AIDS patients on second-line ART from 2016 to 2021. Cox proportional hazard models with a linear mixed effect model were jointly modeled using the JM package of R software with time-dependent lagged parameterizations, and a 95% confidence interval was used to select significant variables.

Results

Overall, 89 HIV/AIDS patients developed unfavorable outcomes. The incidence density was 7.48/100 person-years (95% CI: 6.08, 9.2). Secondary and tertiary educational level (AHR=0.47, 95% CI: 0.25, 0.89, and AHR=0.27, 95% CI: 0.1, 0.72), CD4 count less than 100 cells/mm³ (AHR=2.15, 95% CI: 1.21, 3.83), poor adherence (AHR=3.59, 95% CI: 1.73, 7.49), and TB comorbidity (AHR=2.23, 95% CI: 1.21, 4.14) at the start of second-line ART were significant predictors of incidence of unfavorable outcome. Time-dependent lagged value viral load was significantly associated with the risk of unfavorable outcome (AHR=1.28, 95% CI: 1.01, 1.63).

Conclusion

In the study area, the incidence of an unfavorable outcome of second-line ART was high. Secondary and tertiary educational level, CD4 count less than 100 cells/mm³, poor adherence, and TB comorbidity at the start of second-line ART were significant predictors of incidence of unfavorable outcomes. Thus, strengthening routine viral load measurement, increase patient adherence, intensive counseling, and strong TB screening are needed in the study setting.

Incidence and Predictors of Virological Failure Among Adult HIV/AIDS Patients on Second-Line Anti-Retroviral Therapy, in Selected Public Hospital of Addis Ababa, Ethiopia: Retrospective Follow-Up Study

Introduction

Objective

Methods

Results

Conclusion

HIV-1 Evolutionary Dynamics under Nonsuppressive Antiretroviral Therapy

Prolonged virologic failure on 2nd-line protease inhibitor (PI)-based antiretroviral therapy (ART) without emergence of major protease mutations is well recognized and provides an opportunity to study within-host evolution in long-term viremic individuals. Using next-generation sequencing and in silico haplotype reconstruction, we analyzed whole-genome sequences from longitudinal plasma samples of eight chronically infected HIV-1-positive individuals failing 2nd-line regimens from the French National Agency for AIDS and Viral Hepatitis Research (ANRS) 12249 Treatment as Prevention (TasP) trial. On nonsuppressive ART, there were large fluctuations in synonymous and nonsynonymous variant frequencies despite stable viremia. Reconstructed haplotypes provided evidence for selective sweeps during periods of partial adherence, and viral haplotype competition, during periods of low drug exposure. Drug resistance mutations in reverse transcriptase (RT) were used as markers of viral haplotypes in the reservoir, and their distribution over time indicated recombination. We independently observed linkage disequilibrium decay, indicative of recombination. These data highlight dramatic changes in virus population structure that occur during stable viremia under nonsuppressive ART. IMPORTANCE HIV-1 infections are most commonly initiated with a single founder virus and are characterized by extensive inter- and intraparticipant genetic diversity. However, existing literature on HIV-1 intrahost population dynamics is largely limited to untreated infections, predominantly in subtype B-infected individuals. The manuscript characterizes viral population dynamics in long-term viremic treatment-experienced individuals, which has not been previously characterized. These data are particularly relevant for understanding HIV dynamics but can also be applied to other RNA viruses. With this unique data set we propose that the virus is highly unstable, and we have found compelling evidence of HIV-1 within-host viral diversification, recombination, and haplotype competition during nonsuppressive ART.

Predictors of Virological Failure Among People Living with HIV Switching from an Effective First-Line Antiretroviral Regimen

Aim of this study was to assess the predictors of virological failure (VF) among patients living with HIV (PLWHIV) switching from an effective first-line antiretroviral therapy (ART) regimen, and to evaluate the emergence of resistance-associated mutations. All adult patients enrolled in the Antiviral Response Cohort Analysis cohort who started ART after 2010, with at least 6 months of virological suppression (VS) before ART switch and with an available genotypic resistance test (GRT) at baseline were included. Thirty-two patients out of the 607 PLWHIV included (5.3%) experienced VF after a median of 11 months from ART switch. Younger age (adjusted Hazard Ratio [aHR] 0.96, 95% confidence interval [CI] 0.92-0.99, p = .023), being male who have sex with male (aHR 0.15, 95% CI 0.03-0.69, p = .014), and longer time from VS to ART switch (aHR 0.97, 95% CI 0.95-1.00, p = .021) resulted protective toward VF, while receiving a first-line regimen containing a backbone other than ABC/3TC or TXF/FTC (aHR 3.61, 95% CI 1.00-13.1, p = .050) and a boosted protease inhibitor as anchor drug (aHR 3.34, 95% CI 1.20-9.28, p = .021) were associated with higher risk of VF. GRT at the moment of VF was available only for 13 patients (40.6%). ART switch in patients with stable control of HIV infection is a safe practice, even if particular attention should be paid in certain cases of patients switching from regimens containing low-performance backbones or protease inhibitors.

Disengagement From HIV Care and Failure of Second-Line Therapy in Nigeria: A Retrospective Cohort Study, 2005-2017

BACKGROUND

Understanding the correlates of disengagement from HIV care and treatment failure during second-line antiretroviral therapy (ART) could inform interventions to improve clinical outcomes among people living with HIV (PLHIV).

METHODS

We conducted a retrospective cohort study of PLHIV aged >15 years who started second-line ART at a tertiary center in Nigeria between 2005 and 2017. Participants were considered to have disengaged from care if they had not returned within a year after each clinic visit. Cox proportional hazard models were used to investigate factors associated with: (1) viral failure (HIV-1 RNA >1000 copies/mL), (2) immunologic failure (CD4 count decrease or <100 cells/mm3), and (3) severe weight loss (>10% of bodyweight), after >6 months of second-line ART.

RESULTS

Among 1031 participants, 33% (341) disengaged from care during a median follow-up of 6.9 years (interquartile range 3.7-8.5). Of these, 26% (89/341) subsequently reentered care. Disengagement was associated with male gender, age <30 years, lower education level, and low CD4 count at second-line ART initiation. Among participants with endpoint assessments available, 20% (112/565) experienced viral failure, 32% (257/809) experienced immunologic failure, and 23% (190/831) experienced weight loss. A lower risk of viral failure was associated with professional occupations compared with elementary: adjusted hazard ratio 0.17 (95% confidence interval 0.04 to 0.70).

CONCLUSION

Adverse outcomes were common during second-line ART. However, reengagement is possible and resources should be allocated to focus on retaining PLHIV in care and providing services to trace and reengage those who have disengaged from care.

Characterization of HIV-1 drug resistance among patients with failure of second-line combined antiretroviral therapy in central Ethiopia

BACKGROUND

As a consequence of the improved availability of combined antiretroviral therapy (cART) in resource-limited countries, an emergence of HIV drug resistance (HIVDR) has been observed. We assessed the prevalence and spectrum of HIVDR in patients with failure of second-line cART at two HIV clinics in central Ethiopia.

METHODS

HIV drug resistance was analysed in HIV-1-infected patients with virological failure of second-line cART using the geno2pheno application.

RESULTS

Among 714 patients receiving second-line cART, 44 (6.2%) fulfilled the criteria for treatment failure and 37 were eligible for study inclusion. Median age was 42 years [interquartile range (IQR): 20-45] and 62.2% were male. At initiation of first-line cART, 23 (62.2%) were WHO stage III, mean CD4 cell count was 170.6 (range: 16-496) cells/µL and median (IQR) HIV-1 viral load was 30 220 (7963-82 598) copies/mL. Most common second-line cART regimens at the time of failure were tenofovir disoproxil fumarate (TDF)-lamivudine (3TC)-ritonavir-boosted atazanavir (ATV/r) (19/37, 51.4%) and zidovudine (ZDV)-3TC-ATV/r (9/37, 24.3%). Genotypic HIV-1 resistance testing was successful in 35 (94.6%) participants. We found at least one resistance mutation in 80% of patients and 40% carried a protease inhibitor (PI)-associated mutation. Most common mutations were M184V (57.1%), Y188C (25.7%), M46I/L (25.7%) and V82A/M (25.7%). High-level resistance against the PI ATV (10/35, 28.6%) and lopinavir (LPV) (5/35, 14.3%) was reported. As expected, no resistance mutations conferring integrase inhibitor resistance were detected.

CONCLUSIONS

We found a high prevalence of resistance mutations, also against PIs (40%), as the national standard second-line cART components. Resistance testing before switching to second- or third-line cART is warranted.

Rate of Viral Re-Suppression and Retention to Care Among PLHIV on Second-Line Antiretroviral Therapy at Dessie Comprehensive Specialized Hospital, Northeast Ethiopia: A Retrospective Cohort Study

Background

In Ethiopia, first-line antiretroviral therapy failure is growing rapidly. However, unlike first-line therapy, to date, very little is known about the outcomes of second-line therapy. Thus, this study assessed the rate of viral re-suppression and attrition to care and their predictors among people living with HIV on second-line therapy.

Methods

A retrospective cohort study was conducted on 642 people living with HIV at Dessie Comprehensive Specialized Hospital from October 2016 to November 2019. A proportional Cox regression model was computed to explore predictors of viral re-suppression (viral load less than 1000 copies/mL) and attrition to care.

Results

Out of 642 subjects, 19 (3%), 44 (6.9%), 70 (10.9%), and 509 (79.3%) patients were lost to follow up, died, transferred out, and alive on care, respectively. Similarly, 82.39% (95% CI: 79.24–85.16%) of patients had achieved viral re-suppression, with 96 per 100 person-year rate of re-suppression. Patients who switched timely to second-line therapy were at a higher rate of viral re-suppression than delayed patients [adjusted hazard rate, AHR = 1.43 (95% CI: 1.17–1.74)]. Not having drug substitution history [AHR = 1.25 (95% CI: 1.02–1.52)] was positively associated with viral re-suppression. In contrast, being on anti-TB treatment [AHR = 0.67 (95% CI: 0.49–0.91)] had lower likelihood with viral re-suppression. In the current study, attrition to care was 11% (95% CI: 8.7–13.9%). Ambulatory or bedridden patients were more at risk of attrition to care as compared with workable patients [AHR = 2.61 (95% CI: 1.40–4.87)]. Similarly, being not virally re-suppressed [AHR = 6.87 (95% CI: 3.86–12.23)] and CD4 count ≤450 cells/mm³ [AHR = 2.61 (95% CI: 1.40–4.87)] were also positively associated with attrition to care.

Conclusion

A significant number of patients failed to achieve viral re-suppression and attrition from care. Most identified factors related to patient monitoring. Hence, patient-centered intervention should be strengthened, besides treatment switch.

Prevalence and Factors Associated With Virological Treatment Failure Among Children and Adolescents on Antiretroviral Therapy Attending HIV/AIDS Care and Treatment Clinics in Dodoma Municipality, Central Tanzania

BACKGROUND

As the World Health Organization (WHO) and its joint partners such as USAIDS target achieving 90% sustained virological suppression among children and adolescents living with Human Immunodeficience Virus (HIV)/AIDS, it is imperative to elucidate the current prevalence and factors associated with virological treatment failure for formulation of appropriate strategies. This study was conducted determine the prevalence and factors associated with virological treatment failure among children and adolescents with HIV/AIDS on antiretroviral therapy (ART) attending HIV/AIDS care clinics in Dodoma, Central Tanzania.

METHODS

This was a cross-sectional study of children aged 1-19 years attending 3 HIV/AIDS care clinics in Dodoma (central Tanzania) from November 2018 to February 2019. Sociodemographic and clinical factors were documented, HIV viral load and CD4+ T lymphocytes were evaluated for children on ART for ≥6 months. The primary outcomes were the prevalence and factors associated with viralogic treatment failure.

RESULTS

Of 300 children enrolled, 102 (34%) had virological treatment failure. Poor adherence to ART (adjusted odds ratio [AOR] = 3.221; 95% confidence interval [CI], 1.867-5.558; P = .032), nevirapine regimen (AOR = 3.185; 95% CI, 1.473-6.886; P ≤ .001), not using cotrimoxazole prophylaxis (AOR = 25.56; 95% CI, 3.15-27.55; P = .002) and nondisclosure of HIV status to others (AOR = 7.741; 95% CI, 2.351-25.489; P = .001) were independently associated with virological treatment failure.

CONCLUSIONS

Current prevalence of virological treatment failure among children and adolescents living with HIV on ART remain high. Factors such as ART adherence, nevirapine based regimen, HIV status disclosure to those caring for the child need to be addressed to achieve sustained virological suppression.

Increased acquired protease inhibitor drug resistance mutations in minor HIV-1 quasispecies from infected patients suspected of failing on national second-line therapy in South Africa

BACKGROUND

HIV-1C has been shown to have a greater risk of virological failure and reduced susceptibility towards boosted protease inhibitors (bPIs), a component of second-line combination antiretroviral therapy (cART) in South Africa. This study entailed an evaluation of HIV-1 drug resistance-associated mutations (RAMs) among minor viral populations through high-throughput sequencing genotypic resistance testing (HTS-GRT) in patients on the South African national second-line cART regimen receiving bPIs.

METHODS

During 2017 and 2018, 67 patient samples were sequenced using high-throughput sequencing (HTS), of which 56 samples were included in the final analysis because the patient's treatment regimen was available at the time of sampling. All patients were receiving bPIs as part of their cART. Viral RNA was extracted, and complete pol genes were amplified and sequenced using Illumina HiSeq2500, followed by bioinformatics analysis to quantify the RAMs according to the Stanford HIV Drug Resistance Database.

RESULTS

Statistically significantly higher PI RAMs were observed in minor viral quasispecies (25%; 14/56) compared to non-nucleoside reverse transcriptase inhibitors (9%; 5/56; p = 0.042) and integrase inhibitor RAM (4%; 2/56; p = 0.002). The majority of the drug resistance mutations in the minor viral quasispecies were observed in the V82A mutation (n = 13) in protease and K65R (n = 5), K103N (n = 7) and M184V (n = 5) in reverse transcriptase.

CONCLUSIONS

HTS-GRT improved the identification of PI and reverse transcriptase inhibitor (RTI) RAMs in second-line cART patients from South Africa compared to the conventional GRT with ≥20% used in Sanger-based sequencing. Several RTI RAMs, such as K65R, M184V or K103N and PI RAM V82A, were identified in < 20% of the population. Deep sequencing could be of greater value in detecting acquired resistance mutations early.

Mechanistic Analysis of the Broad Antiretroviral Resistance Conferred by HIV-1 Envelope Glycoprotein Mutations

Despite the effectiveness of antiretroviral (ARV) therapy, virological failure can occur in some HIV-1-infected patients in the absence of mutations in drug target genes. We previously reported that, in vitro, the lab-adapted HIV-1 NL4-3 strain can acquire resistance to the integrase inhibitor dolutegravir (DTG) by acquiring mutations in the envelope glycoprotein (Env) that enhance viral cell-cell transmission. In this study, we investigated whether Env-mediated drug resistance extends to ARVs other than DTG and whether it occurs in other HIV-1 isolates. We demonstrate that Env mutations can reduce susceptibility to multiple classes of ARVs and also increase resistance to ARVs when coupled with target-gene mutations. We observe that the NL4-3 Env mutants display a more stable and closed Env conformation and lower rates of gp120 shedding than the WT virus. We also selected for Env mutations in clinically relevant HIV-1 isolates in the presence of ARVs. These Env mutants exhibit reduced susceptibility to DTG, with effects on replication and Env structure that are HIV-1 strain dependent. Finally, to examine a possible in vivo relevance of Env-mediated drug resistance, we performed single-genome sequencing of plasma-derived virus from five patients failing an integrase inhibitor-containing regimen. This analysis revealed the presence of several mutations in the highly conserved gp120-gp41 interface despite low frequency of resistance mutations in integrase. These results suggest that mutations in Env that enhance the ability of HIV-1 to spread via a cell-cell route may increase the opportunity for the virus to acquire high-level drug resistance mutations in ARV target genes.IMPORTANCE Although combination antiretroviral (ARV) therapy is highly effective in controlling the progression of HIV disease, drug resistance can be a major obstacle. Recent findings suggest that resistance can develop without ARV target gene mutations. We previously reported that mutations in the HIV-1 envelope glycoprotein (Env) confer resistance to an integrase inhibitor. Here, we investigated the mechanism of Env-mediated drug resistance and the possible contribution of Env to virological failure in vivo We demonstrate that Env mutations can reduce sensitivity to major classes of ARVs in multiple viral isolates and define the effect of the Env mutations on Env subunit interactions. We observed that many Env mutations accumulated in individuals failing integrase inhibitor therapy despite a low frequency of resistance mutations in integrase. Our findings suggest that broad-based Env-mediated drug resistance may impact therapeutic strategies and provide clues toward understanding how ARV-treated individuals fail therapy without acquiring mutations in drug target genes.

The impact of Gag non-cleavage site mutations on HIV-1 viral fitness from integrative modelling and simulations

The high mutation rate in retroviruses is one of the leading causes of drug resistance. In human immunodeficiency virus type-1 (HIV-1), synergistic mutations in its protease and the protease substrate - the Group-specific antigen (Gag) polyprotein - work together to confer drug resistance against protease inhibitors and compensate the mutations affecting viral fitness. Some Gag mutations can restore Gag-protease binding, yet most Gag-protease correlated mutations occur outside of the Gag cleavage site. To investigate the molecular basis for this, we now report multiscale modelling approaches to investigate various sequentially cleaved Gag products in the context of clinically relevant mutations that occur outside of the cleavage sites, including simulations of the largest Gag proteolytic product in its viral membrane-bound state. We found that some mutations, such as G123E and H219Q, involve direct interaction with cleavage site residues to influence their local environment, while certain mutations in the matrix domain lead to the enrichment of lipids important for Gag targeting and assembly. Collectively, our results reveal why non-cleavage site mutations have far-reaching implications outside of Gag proteolysis, with important consequences for drugging Gag maturation intermediates and tackling protease inhibitor resistance.

Virological failure and HIV drug resistance among adults living with HIV on second-line antiretroviral therapy in the Asia-Pacific

OBJECTIVES

To assess second-line antiretroviral therapy (ART) virological failure and HIV drug resistance-associated mutations (RAMs), in support of third-line regimen planning in Asia.

METHODS

Adults > 18 years of age on second-line ART for ≥ 6 months were eligible. Cross-sectional data on HIV viral load (VL) and genotypic resistance testing were collected or testing was conducted between July 2015 and May 2017 at 12 Asia-Pacific sites. Virological failure (VF) was defined as VL > 1000 copies/mL with a second VL > 1000 copies/mL within 3-6 months. FASTA files were submitted to Stanford University HIV Drug Resistance Database and RAMs were compared against the IAS-USA 2019 mutations list. VF risk factors were analysed using logistic regression.

RESULTS

Of 1378 patients, 74% were male and 70% acquired HIV through heterosexual exposure. At second-line switch, median [interquartile range (IQR)] age was 37 (32-42) years and median (IQR) CD4 count was 103 (43.5-229.5) cells/µL; 93% received regimens with boosted protease inhibitors (PIs). Median duration on second line was 3 years. Among 101 patients (7%) with VF, CD4 count > 200 cells/µL at switch [odds ratio (OR) = 0.36, 95% confidence interval (CI): 0.17-0.77 vs. CD4 ≤ 50) and HIV exposure through male-male sex (OR = 0.32, 95% CI: 0.17-0.64 vs. heterosexual) or injecting drug use (OR = 0.24, 95% CI: 0.12-0.49) were associated with reduced VF. Of 41 (41%) patients with resistance data, 80% had at least one RAM to nonnucleoside reverse transcriptase inhibitors (NNRTIs), 63% to NRTIs, and 35% to PIs. Of those with PI RAMs, 71% had two or more.

CONCLUSIONS

There were low proportions with VF and significant RAMs in our cohort, reflecting the durability of current second-line regimens.

In Vivo Emergence of a Novel Protease Inhibitor Resistance Signature in HIV-1 Matrix

Protease inhibitors (PIs) are the second- and last-line therapy for the majority of HIV-infected patients worldwide. Only around 20% of individuals who fail PI regimens develop major resistance mutations in protease. We sought to explore the role of mutations in gag-pro genotypic and phenotypic changes in viruses from six Nigerian patients who failed PI-based regimens without known drug resistance-associated protease mutations in order to identify novel determinants of PI resistance. Target enrichment and next-generation sequencing (NGS) with the Illumina MiSeq system were followed by haplotype reconstruction. Full-length Gag-protease gene regions were amplified from baseline (pre-PI) and virologic failure (VF) samples, sequenced, and used to construct gag-pro-pseudotyped viruses. Phylogenetic analysis was performed using maximum-likelihood methods. Susceptibility to lopinavir (LPV) and darunavir (DRV) was measured using a single-cycle replication assay. Western blotting was used to analyze Gag cleavage. In one of six participants (subtype CRF02_AG), we found 4-fold-lower LPV susceptibility in viral clones during failure of second-line treatment. A combination of four mutations (S126del, H127del, T122A, and G123E) in the p17 matrix of baseline virus generated a similar 4-fold decrease in susceptibility to LPV but not darunavir. These four amino acid changes were also able to confer LPV resistance to a subtype B Gag-protease backbone. Western blotting demonstrated significant Gag cleavage differences between sensitive and resistant isolates in the presence of drug. Resistant viruses had around 2-fold-lower infectivity than sensitive clones in the absence of drug. NGS combined with haplotype reconstruction revealed that resistant, less fit clones emerged from a minority population at baseline and thereafter persisted alongside sensitive fitter viruses. We used a multipronged genotypic and phenotypic approach to document emergence and temporal dynamics of a novel protease inhibitor resistance signature in HIV-1 matrix, revealing the interplay between Gag-associated resistance and fitness.

Outcomes of patients on second- and third-line ART enrolled in ART adherence clubs in Maputo, Mozambique

Objectives

Adherence clubs (AC) offer patient‐centred access to antiretroviral therapy (ART) while reducing the burden on health facilities. AC were implemented in a health centre in Mozambique specialising in patients with a history of HIV treatment failure. We explored the impact of AC on retention in care and VL suppression of these patients.

Methods

We performed a retrospective analysis of patients enrolled in AC receiving second‐ or third‐line ART. The Kaplan–Meier estimates were used to analyse retention in care in health facility, retention in AC and viral load (VL) suppression (VL < 1000 copies/mL). Predictors of attrition and VL rebound (VL ≥ 1000 copies/mL) were assessed using multivariable proportional hazards regression.

Results

The analysed cohort contained 699 patients, median age 40 years [IQR: 35–47], 428 (61%) female and 97% second‐line ART. Overall, 9 (1.3%) patients died, and 10 (1.4%) were lost to follow‐up. Retention in care at months 12 and 24 was 98.9% (95% CI: 98.2–99.7) and 96.4% (95% CI: 94.6–98.2), respectively. Concurrently, 85.8% (95% CI: 83.1–88.2) and 80.9% (95% CI: 77.8–84.1) of patients maintained VL suppression. No association between predictors and all‐cause attrition or VL rebound was detected. Among 90 patients attending AC and simultaneously having VL rebound, 64 (71.1%) achieved VL resuppression, 10 (11.1%) did not resuppress, and 14 (15.6%) had no subsequent VL result.

Conclusion

Implementation of AC in Mozambique was successful and demonstrated that patients with a history of HIV treatment failure can be successfully retained in care and have high VL suppression rate when enrolled in AC. Expansion of the AC model in Mozambique could improve overall retention in care and VL suppression while reducing workload in health facilities.

Incidence and factors associated with treatment failure among HIV infected adolescent and adult patients on second-line antiretroviral therapy in public hospitals of Northern Ethiopia: Multicenter retrospective study

BACKGROUND

This study aimed to determine the incidence and factors associated with treatment failure among HIV infected adolescent and adult patients on second-line antiretroviral therapy (ART) in public hospitals of Northern Ethiopia.

METHODS

A retrospective study was conducted from September 1, 2007 to July 30, 2017 on 227 patients. The data were extracted using a retrieval checklist from the patient's charts. The incidence rate of treatment failure was calculated using Kaplan-Meier methods and Cox proportional hazard model was used to assess factors associated with treatment failure.

RESULT

The study subjects were followed for a total observation of 788.58 person-years with a median follow-up period of 35 (IQR: 17-60) months after switching to second-line ART. About 57 (25.11%) patients developed treatment failure, out of which, 32 (56.14%) occurred during the first two years. The overall incidence of second-line treatment failure was 72.3 per 1000 person years (95%CI: 55.75-93.71) of observation. The Kaplan-Meier estimates of cumulative treatment failure after 1, 2, and around 10 years of follow-up were 12.31% (95%CI: 8.60-17.45%), 14.99% (95%CI: 10.82%-20.57%), and 48.67% (95%CI: 32.45-67.81%) respectively. Age >45 years AHR = 3.33, 95%CI = 1.33-8.31), WHO stage IV (AHR = 3.63, 95%CI = 1.72-7.67), CD4 count <100 cells/mm3 (AHR = 3.79, 95%CI = 1.61-8.91), TB co-morbidity (AHR = 3.39 95%CI = 1.91-6.01) and poor adherence level (AHR = 3.63, 95% CI = 1.89-6.96) at the start of second line ART were significantly associated with second-line ART failure.

CONCLUSION

Incidence of second-line ART treatment failure in the first 2 years of follow-up was high. The rate of second-line ART failure was higher in patients who started second-line ART with poor drug adherence, CD4 count <100 cells/mm3, TB co-morbidity, age >45 years, and being in WHO stage IV. Therefore, intensive counseling and adherence support should be given along with strong TB screening. Moreover, the government of Ethiopia should consider endorsing third-line ART drugs after careful cost-benefit analysis.

Baseline PI susceptibility by HIV-1 Gag-protease phenotyping and subsequent virological suppression with PI-based second-line ART in Nigeria

Objectives

Previous work showed that gag-protease-derived phenotypic susceptibility to PIs differed between HIV-1 subtype CRF02_AG/subtype G-infected patients who went on to successfully suppress viral replication versus those who experienced virological failure of lopinavir/ritonavir monotherapy as first-line treatment in a clinical trial. We analysed the relationship between PI susceptibility and outcome of second-line ART in Nigeria, where subtypes CRF02_AG/G dominate the epidemic.

Methods

Individuals who experienced second-line failure with ritonavir-boosted PI-based ART were matched (by subtype, sex, age, viral load, duration of treatment and baseline CD4 count) to those who achieved virological response (‘successes’). Successes were defined by viral load <400 copies of HIV-1 RNA/mL by week 48. Full-length Gag-protease was amplified from patient samples for in vitro phenotypic susceptibility testing, with PI susceptibility expressed as IC₅₀ fold change (FC) relative to a subtype B reference strain.

Results

The median (IQR) lopinavir IC₅₀ FC was 4.04 (2.49–7.89) for virological failures and 4.13 (3.14–8.17) for virological successes (P = 0.94). One patient had an FC >10 for lopinavir at baseline and experienced subsequent virological failure with ritonavir-boosted lopinavir as the PI. There was no statistically significant difference in single-round replication efficiency between the two groups (P = 0.93). There was a moderate correlation between single-round replication efficiency and FC for lopinavir (correlation coefficient 0.32).

Conclusions

We found no impact of baseline HIV-1 Gag-protease-derived phenotypic susceptibility on outcomes of PI-based second-line ART in Nigeria.

Second line anti-retroviral therapy failure in a pediatric cohort of an Ethiopian tertiary hospital: a retrospective observational study

Sub-Saharan Africa carries the largest burden of pediatric HIV infection. The success of second line anti-retroviral treatment and related factors among African children is not well-defined. Objectives: We aimed to identify the rate and determinants of second line anti-retroviral treatment failure among children and adolescents on follow-up at an Ethiopian tertiary teaching hospital. A retrospective observational cohort study was conducted at Tikur Anbessa Specialized Hospital, Addis Ababa. Structured forms were used to collect socio-demographic, clinical and diagnostic data. Descriptive statistics and bivariate analysis were used to describe the magnitude of the problem and its associations. A total of 76 children and adolescents taking second line anti-retroviral treatment were analyzed (mean age: 16.1 years). Failure of therapy was seen in 14/76 while four were eligible for a switch to third line anti-retrovirals. Mean duration on second line treatment till virologic failure was diagnosed was 17.6 months while mean viral load upon requiring a third line regimen was 82,131.3 copies/ml. Second line antiretroviral treatment virologic failure was significantly associated with the age of the child or adolescent. A high rate of virologic failure exists among the study population. Findings underline need for provision of third line anti-retroviral drugs in Ethiopia. Challenges for delivering a standard care were irregular viral load testing and delayed initiation of second line treatment after failure of first line regimens.

Drug Resistance Mutations Against Protease, Reverse Transcriptase and Integrase Inhibitors in People Living With HIV-1 Receiving Boosted Protease Inhibitors in South Africa

The South African national combination antiretroviral therapy (cART) roll-out program started in 2006, with over 4.4 million people accessing treatment since it was first introduced. HIV-1 drug resistance can hamper the success of cART. This study determined the patterns of HIV-1 drug-resistance associated mutations (RAMs) in People Living with HIV-1 (PLHIV-1). Receiving first (for children below 3 years of age) and second-line (for adults) cART regimens in South Africa. During 2017 and 2018, 110 patients plasma samples were selected, 96 samples including those of 17 children and infants were successfully analyzed. All patients were receiving a boosted protease inhibitor (bPI) as part of their cART regimen. The viral sequences were analyzed for RAMs through genotypic resistance testing. We performed genotypic resistance testing (GRT) for Protease inhibitors (PIs), Reverse transcriptase inhibitors (RTIs) and Integrase strand transfer inhibitors (InSTIs). Viral sequences were subtyped using REGAv3 and COMET. Based on the PR/RT sequences, HIV-1 subtypes were classified as 95 (99%) HIV-1 subtype C (HIV-1C) while one sample as 02_AG. Integrase sequencing was successful for 89 sequences, and all the sequences were classified as HIV-1C (99%, 88/89) except one sequence classified CRF02_AG, as observed in PR/RT. Of the 96 PR/RT sequences analyzed, M184V/I (52/96; 54%) had the most frequent RAM nucleoside reverse transcriptase inhibitor (NRTI). The most frequent non-nucleoside reverse transcriptase inhibitor (NNRTI) RAM was K103N/S (40/96, 42%). Protease inhibitor (PI) RAMs M46I and V82A were present in 12 (13%) of the sequences analyzed. Among the InSTI major RAM two (2.2%) sequences have Y143R and T97A mutations while one sample had T66I. The accessory RAM E157Q was identified in two (2.2%). The data indicates that the majority of the patients failed on bPIs didn't have any mutation; therefore adherence could be major issue in these groups of individuals. We propose continued viral load monitoring for better management of infected PLHIV.

Viral suppression in adults, adolescents and children receiving antiretroviral therapy in Cameroon: adolescents at high risk of virological failure in the era of "test and treat"

BACKGROUND

After the launching of the « Test & Treat » strategy and the wider accessibility to viral load (VL), evaluating virological success (VS) would help in meeting the UNAIDS targets by 2020 in Cameroon.

SETTING AND METHODS

Cross-sectional study conducted in the Chantal BIYA International Reference Centre for research on HIV/AIDS prevention and management (CIRCB), Yaoundé, Cameroon; data generated between October 2016 and August 2017 amongst adults, adolescents and children at 12, 24, 36 and ≥ 48 months on ART. VS was defined as < 1000 copies/mL of blood plasma and controlled viremia as VL < 50 copies/mL. Data were analysed by SPSS; p < 0.05 considered as significant.

RESULTS

1946 patients (70% female) were enrolled (1800 adults, 105 adolescents, 41 children); 1841 were on NNRTI-based and 105 on PI-based therapy; with 346 patients at M12, 270 at M24, 205 at M36 and 1125 at ≥ M48. The median (IQR) duration on was 48 months (24-48). Overall, VS was 79.4% (95% CI 77.6-81.2) and 67.1% (95% CI 64.9-69.1) had controlled viral replication. On NNRTI-based, VS was 79.9% vs. 71.4% on PIs-based, p = 0.003. By ART duration, VS was 84.1% (M12), 85.9% (M24), 75.1% (M36) and 77.2% (≥ M48), p = 0.001. By age, VS was 75.6% (children), 53.3% (adolescents) and 81.1% (adults), p < 0.001.

CONCLUSIONS

In this sub-population of patients receiving ART in Cameroon, about 80% might be experiencing VS, with declining performance at adolescence, with NNRTI-based regimens, and as from 36 months on ART. Thus, improving VS may require an adapted adherence support mechanism, especially for adolescents with long-term treatment in resource-limited settings.

Third-Line Antiretroviral Therapy Program in the South African Public Sector: Cohort Description and Virological Outcomes

Background:

The World Health Organization recommends that antiretroviral therapy (ART) programs in resource-limited settings develop third-line ART policies. South Africa developed a national third-line ART program for patients who have failed both first-line non-nucleoside reverse transcriptase inhibitor–based ART and second-line protease inhibitor (PI)-based ART. We report on this program.

Methods:

Third-line ART in South Africa is accessed through a national committee that assesses eligibility and makes individual regimen recommendations. Criteria for third-line include the following: ≥1 year on PI-based ART with virologic failure, despite adherence optimization, and genotypic antiretroviral resistance test showing PI resistance. We describe baseline characteristics and resistance patterns of this cohort and present longitudinal data on virological suppression rates.

Results:

Between August 2013 and July 2014, 144 patients were approved for third-line ART. Median age was 41 years [interquartile range (IQR): 19–47]; 60% were women (N = 85). Median CD4⁺ count and viral load were 172 (IQR: 128–351) and 14,759 (IQR: 314–90,378), respectively. About 2.8% started PI-based ART before 2004; 11.1% from 2004 to 2007; 31.3% from 2008 to 2011; and 6.3% from 2012 to 2014 (48.6% unknown start date). Of the 144 patients, 97% and 98% had resistance to lopinavir and atazanavir, respectively; 57% had resistance to darunavir. All were initiated on a regimen containing darunavir, with raltegravir in 101, and etravirine in 33. Among those with at least 1 viral load at least 6 months after third-line approval (n = 118), a large proportion (83%, n = 98) suppressed to <1000 copies per milliliter, and 79% (n = 93) to <400 copies per milliliter.

Conclusion:

A high proportion of third-line patients with follow-up viral loads are virologically suppressed.

Implementation of an intensive adherence intervention in patients with second-line antiretroviral therapy failure in four west African countries with little access to genotypic resistance testing: a prospective cohort study

BACKGROUND

The decision about whether to switch to third-line antiretroviral therapy (ART) in patients with treatment failure on second-line therapy is difficult in settings with little access to genotypic resistance testing. In this study, we used a standardised algorithm including a wide range of adherence-enhancing interventions followed by a new viral load measurement to decide whether to switch to third-line therapy in this situation. The decision, made on the basis of effectiveness of the adherence reinforcement to drive viral resuppression, did not use genotypic resistance testing.

METHODS

In this prospective cohort study, adults in four west African countries with treatment failure of a boosted protease inhibitor ART regimen were offered nine adherence reinforcement interventions, and followed up for 64 weeks. We measured viral load at week 12 and used the results to decide ART treatment at week 16: if successful resuppression (plasma HIV-1 RNA <400 copies per mL or had decreased by ≥2 log₁₀ copies per mL compared with baseline), patients continued the same second-line regimen; otherwise they switched to a third-line regimen based on ritonavir-boosted darunavir and raltegravir. The primary endpoint was virological success at week 64 (plasma HIV-1 RNA <50 copies per mL). After study termination we did genotypic resistance testing on frozen plasma samples collected at baseline, and retrospectively determined the appropriateness of the week 16 decision on the basis of the baseline genotypic susceptibility score.

FINDINGS

Between March 28, 2013, and May 11, 2015, of the 198 eligible participants, five died before week 16. Of the 193 remaining, 130 (67%) reached viral resuppression and continued with second-line ART, and 63 (33%) switched to third-line ART at week 16. Post-study genotypic resistance testing showed that the baseline genotypic susceptibility score was calculable in 166 patients, of whom 57 (34%) had a score less than 2. We retrospectively concluded that the week 16 decision was appropriate in 145 (75%) patients. At week 64, four patients (2%) were lost to follow-up, ten (5%) had died, and 101 (52%) had a viral load less than 50 copies per mL.

INTERPRETATION

Poor adherence is the first problem to tackle in patients for whom second-line ART is failing when resistance tests are not routinely available and is effectively a manageable problem. Lack of access to genotypic resistance testing should not be an obstacle to the prescription of third-line ART in patients who do not achieve viral resuppression after adherence reinforcement.

FUNDING

French Agency for Research on AIDS and Viral Hepatitis.

Second-line HIV treatment failure in sub-Saharan Africa: A systematic review and meta-analysis

BACKGROUND

Increased second-line antiretroviral therapy (ART) failure rate narrows future options for HIV/AIDS treatment. It has critical implications in resource-limited settings; including sub-Saharan Africa (SSA) where the burden of HIV-infection is immense. Hence, pooled estimate for second-line HIV treatment failure is relevant to suggest valid recommendations that optimize ART outcomes in SSA.

METHODS

We retrieved literature systematically from PUBMED/MEDLINE, EMBASE, CINAHL, Google Scholar, and AJOL. The retrieved studies were screened and assessed for eligibility. We also assessed the eligible studies for their methodological quality using the Joanna Briggs Institute's appraisal checklist. The pooled estimates for second-line HIV treatment failure and its associated factors were determined using STATA, version 15.0 and MEDCALC, version 18.11.3, respectively. We assessed publication bias using Comprehensive Meta-analysis software, version 3. Detailed study protocol for this review/meta-analysis is registered and found on PROSPERO (ID: CRD42018118959).

RESULTS

A total of 33 studies with the overall 18,550 participants and 19,988.45 person-years (PYs) of follow-up were included in the review. The pooled second-line HIV treatment failure rate was 15.0 per 100 PYs (95% CI: 13.0-18.0). It was slightly higher at 12-18 months of follow-up (19.0/100 PYs; 95% CI: 15.0-22.0), in children (19.0/100 PYs; 95% CI: 14.0-23.0) and in southern SSA (18.0/100 PYs; 95% CI: 14.0-23.0). Baseline values (high viral load (OR: 5.67; 95% CI: 13.40-9.45); advanced clinical stage (OR: 3.27; 95% CI: 2.07-5.19); and low CD4 counts (OR: 2.80; 95% CI: 1.83-4.29)) and suboptimal adherence to therapy (OR: 1.92; 95% CI: 1.28-2.86) were the factors associated with increased failure rates.

CONCLUSION

Second-line HIV treatment failure has become highly prevalent in SSA with alarming rates during the 12-18 month period of treatment start; in children; and southern SSA. Therefore, the second-line HIV treatment approach in SSA should critically consider excellent adherence to therapy, aggressive viral load suppression, and rapid immune recovery.

HIV-1 drug resistance testing at second-line regimen failure in Arua, Uganda: avoiding unnecessary switch to an empiric third-line

OBJECTIVES

The number of patients on second-line antiretroviral therapy is growing, but data on HIV drug resistance patterns at failure in resource-constrained settings are scarce. We aimed to describe drug resistance and investigate the factors associated with extensive resistance to nucleoside/nucleotide reverse transcriptase inhibitors (NRTI), in patients failing second-line therapy in the HIV outpatient clinic at Arua Regional Referral Hospital, Uganda.

METHODS

We included patients who failed on second-line therapy (two consecutive viral loads ≥1000 copies/mm³ by SAMBA-1 point-of-care test) and who had a drug resistance test performed between September 2014 and March 2017. Logistic regression was used to investigate factors associated with NRTI genotypic sensitivity score (GSS) ≤1.

RESULTS

Seventy-eight patients were included: 42% female, median age 31 years and median time of 29 months on second-line therapy. Among 70 cases with drug resistance test results, predominant subtypes were A (47%) and D (40%); 18.5% had ≥1 major protease inhibitor mutation; 82.8% had ≥1 NRTI mutation and 38.5% had extensive NRTI resistance (NRTI GSS ≤1). A nadir CD4 count ≤100/ml was associated with NRTI GSS ≤1 (OR 4.2, 95% CI [1.3-15.1]). Thirty (42.8%) patients were switched to third-line therapy, composed of integrase inhibitor and protease inhibitor (60% darunavir/r) +/- NRTI. A follow-up viral load was available for 19 third-line patients at 12 months: 84.2% were undetectable.

CONCLUSIONS

Our study highlights the need for access to drug resistance tests to avoid unnecessary switches to third-line therapy, but also for access to third-line drugs, in particular integrase inhibitors. Low nadir CD4 count might be an indicator of third-line drug requirement for patients failing second-line therapy.

HIV-1 second-line failure and drug resistance at high-level and low-level viremia in Western Kenya

OBJECTIVE

Characterize failure and resistance above and below guidelines-recommended 1000 copies/ml virologic threshold, upon second-line failure.

DESIGN

Cross-sectional study.

METHODS

Kenyan adults on lopinavir/ritonavir-based second-line were enrolled at AMPATH (Academic Model Providing Access to Healthcare). Charts were reviewed for demographic/clinical characteristics and CD4/viral load were obtained. Participants with detectable viral load had a second visit and pol genotyping was attempted in both visits. Accumulated resistance was defined as mutations in the second, not the first visit. Low-level viremia (LLV) was detectable viral load less than 1000 copies/ml. Failure and resistance associations were evaluated using logistic and Poisson regression, Fisher Exact and t-tests.

RESULTS

Of 394 participants (median age 42, 60% women, median 1.9 years on second-line) 48% had detectable viral load; 21% had viral load more than 1000 copies/ml, associated with younger age, tuberculosis treatment, shorter time on second-line, lower CD4count/percentage, longer first-line treatment interruption and pregnancy. In 105 sequences from the first visit (35 with LLV), 79% had resistance (57% dual-class, 7% triple-class; 46% with intermediate-to-high-level resistance to ≥1 future drug option). LLV was associated with more overall and NRTI-associated mutations and with predicted resistance to more next-regimen drugs. In 48 second-visit sequences (after median 55 days; IQR 28-33), 40% accumulated resistance and LLV was associated with more mutation accumulation.

CONCLUSION

High resistance upon second-line failure exists at levels above and below guideline-recommended virologic-failure threshold, impacting future treatment options. Optimization of care should include increased viral load monitoring, resistance testing and third-line ART access, and consideration of lowering the virologic failure threshold, though this demands further investigation.

Predictors of switch to and early outcomes on third-line antiretroviral therapy at a large public-sector clinic in Johannesburg, South Africa

BACKGROUND

While efficacy data exist, there are limited data on the outcomes of patients on third-line antiretroviral therapy (ART) in sub-Saharan Africa in actual practice. Being able to identify predictors of switch to third-line ART will be essential for planning for future need. We identify predictors of switch to third-line ART among patients with significant viraemia on a protease inhibitor (PI)-based second-line ART regimen. Additionally, we describe characteristics of all patients on third-line at a large public sector HIV clinic and present their early outcomes.

METHODS

Retrospective analysis of adults (≥ 18 years) on a PI-based second-line ART regimen at Themba Lethu Clinic, Johannesburg, South Africa as of 01 August 2012, when third-line treatment became available in South Africa, with significant viraemia on second-line ART (defined as at least one viral load ≥ 1000 copies/mL on second-line ART after 01 August 2012) to identify predictors of switch to third-line (determined by genotype resistance testing). Third-line ART was defined as a regimen containing etravirine, raltegravir or ritonavir boosted darunavir, between August 2012 and January 2016. To assess predictors of switch to third-line ART we used Cox proportional hazards regression among those with significant viraemia on second-line ART after 01 August 2012. Then among all patients on third-line ART we describe viral load suppression, defined as a viral load < 400 copies/mL, after starting third-line ART.

RESULTS

Among 719 patients in care and on second-line ART as of August 2012 (with at least one viral load ≥ 1000 copies/mL after 01 August 2012), 36 (5.0% over a median time of 54 months) switched to third-line. Time on second-line therapy (≥ 96 vs. < 96 weeks) (adjusted Hazard Ratio (aHR): 2.53 95% CI 1.03-6.22) and never reaching virologic suppression while on second-line ART (aHR: 3.37 95% CI 1.47-7.73) were identified as predictors of switch. In a separate cohort of patients on third-line ART, 78.3% (47/60) and 83.3% (35/42) of those in care and with a viral load suppressed their viral load at 6 and 12 months, respectively.

CONCLUSIONS

Our results show that the need for third-line is low (5%), but that patients' who switch to third-line ART have good early treatment outcomes and are able to suppress their viral load. Adherence counselling and resistance testing should be prioritized for patients that are at risk of failure, in particular those who never suppress on second-line and those who have been on PI-based regimen for extended periods.

Positive Virological Outcomes of HIV-Infected Patients on Protease Inhibitor-Based Second-Line Regimen in Cambodia: The ANRS 12276 2PICAM Study

Background

Assessment of virological outcomes among HIV-infected patients receiving protease (PR) inhibitor-based second-line regimen are uncommon in Cambodia. The objective of this study is to assess the virological effectiveness of this regimen as well as impact of adherence boosting for patients experiencing virological failure.

Methods

The 2PICAM study (Clinicaltrial: NCT01801618) is a cross-sectional study of HIV-infected adults on PR inhibitor-based second-line regimen since at least 6 months, conducted in 13 representative sites, comprising more than 90% of the target population. Adults with HIV RNA above 250 copies/mL (threshold of the assay) at inclusion received boosted adherence counseling during 3 months followed by HIV RNA control. For confirmed virological failure, genotype resistance test was performed and expert committee used results for therapeutic decision.

Results

Among the 1,317 adults enrolled, the median duration of second-line regimen was 5 years. At inclusion, 1,182 (89.7%) patients achieved virological success (<250 copies/mL) and 135 (10.3%) experienced a virological failure (>250 copies/mL). In multivariable analysis, factors associated with virological success were: CD4 cell count between 201 and 350/mm³ (OR: 4.66, 95% CI: 2.57–8.47, p < 0.0001) and >350/mm³ (OR: 6.67, 95% CI: 4.02–11.06, p < 0.0001), duration of PI-based regimen >2 years (OR: 1.64, 95% CI: 1.03–2.62, p = 0.037), ATV-containing regimen (0R: 1.65, 95% CI: 1.04–2.63, p = 0.034) and high level of adherence (OR: 2.41, 95% CI: 1.07–5.41, p = 0.033). After adherence counseling, 63 (46.7%) patients were rescued while 72 (53.3%) were not. For the 54 patients with genotype resistance tests available, high or intermediate levels of resistance to lopinavir, atazanavir, and darunavir were reported for 13 (24%), 12 (22.2%), and 2 (3.7%) patients, respectively. Change to an alternative PR inhibitor-based regimen was recommended for 17 patients and to third-line regimen, including integrase inhibitors for 12.

Conclusion

This study reports high rate of virological suppression of second-line regimen and importance of adherence boosting prior to deciding any change of ART regimen. Genotype resistance tests appear necessary to guide decisions. Such information was of great importance for National HIV Program to adapt guidelines and program needs for third-line regimen.

Human Immunodeficiency Virus-1 Drug Resistance Patterns Among Adult Patients Failing Second-Line Protease Inhibitor-Containing Regimens in Namibia, 2010-2015

Three hundred sixty-six adult patients in Namibia with second-line virologic failures were evaluated for human immunodeficiency virus drug-resistant (HIVDR) mutations. Less than half (41.5%) harbored ≥1 HIVDR mutations to standardized second-line antiretroviral therapy (ART) regimen. Optimizing adherence, viral load monitoring, and genotyping are critical to prevent emergence of resistance, as well as unnecessary switching to costly third-line ART regimens.

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.