Beyond first-line HIV treatment regimens: the current state of antiretroviral regimens, viral load monitoring, and resistance testing in resource-limited settings. Curr Opin HIV AIDS. 2013;8:586-590. [PMID: 24100872 DOI: 10.1097/coh.0000000000000004]

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.

Genotyping and outcomes of presumptive second line ART failure cases switched to third line or maintained on second line ART in Mumbai, India

Background

HIV programs are increasingly confronted with failing antiretroviral therapy (ART), including second-line regimens. WHO has provided guidelines on switching to third-line ART. In a Médecins Sans Frontières clinic in Mumbai, India, receiving referred presumptive second-line ART failure cases, an evidence-based protocol consisting of viral load (VL) testing, enhanced adherence counselling (EAC) and genotype for switching was implemented.

Objective

To document the outcome and genotype of presumptive second-line ART failure cases switched to third-line or maintained on second-line ART.

Design

Retrospective cohort study of patients referred between January 2011 and September 2017.

Results

The cases (n = 120) were complex with median 9.2 years of ART exposure, poor adherence at baseline, and exposure to multiple ART regimens other than recommended by WHO. Out of 90 evaluated cases, 39(43%) were maintained on second-line ART. Forty-nine (54%) were ever switched to third-line ART. Twelve months virological suppression was 72% in the second-line and 93% in the third-line ART cohort, while retention in care was 80% and 94% respectively. Genotyping showed 62% resistance for PIs, and 52% triple class resistance to NRTIs, NNRTIs and PIs. Resistance was noted for the new class of integrase inhibitors, and for different drugs without any documented previous exposure to the same drug.

Conclusion

Adopting WHO guidelines on switching ART regimens and provision of EAC can prevent unnecessary switching/exposure to third-line ART regimens. Genotyping is urgently required in national HIV programs, which currently use only the exposure history of patients for switching to third-line ART regimens.

High Levels of Dual-Class Drug Resistance in HIV-Infected Children Failing First-Line Antiretroviral Therapy in Southern Ethiopia

Clinical monitoring of pediatric HIV treatment remains a major challenge in settings where drug resistance genotyping is not routinely available. As a result, our understanding of drug resistance, and its impact on subsequent therapeutic regimens available in these settings, remains limited. We investigate the prevalence and correlates of HIV-1 drug resistance among 94 participants of the Ethiopia Pediatric HIV Cohort failing first-line combination antiretroviral therapy (cART) using dried blood spot-based genotyping. Overall, 81% (73/90) of successfully genotyped participants harbored resistance mutations, including 69% (62/90) who harbored resistance to both Nucleoside Reverse Transcriptase Inhibitors (NRTIs) and Non-nucleoside Reverse Transcriptase Inhibitors (NNRTIs). Strikingly, 42% of resistant participants harbored resistance to all four NRTIs recommended for second-line use in this setting, meaning that there are effectively no remaining cART options for these children. Longer cART duration and prior regimen changes were significantly associated with detection of drug resistance mutations. Replicate genotyping increased the breadth of drug resistance detected in 34% of cases, and thus is recommended for consideration when typing from blood spots. Implementation of timely drug resistance testing and access to newer antiretrovirals and drug classes are urgently needed to guide clinical decision-making and improve outcomes for HIV-infected children on first-line cART in Ethiopia.

Growing challenges for HIV programmes in Asia: clinic population trends, 2003-2013

The scale-up of antiretroviral therapy (ART) has led to a substantial change in the clinical population of HIV-positive patients receiving care. We describe the temporal trends in the demographic and clinical characteristics of HIV-positive patients initiating ART in 2003-13 within an Asian regional cohort. All HIV-positive adult patients that initiated ART between 2003 and 2013 were included. We summarized ART regimen use, age, CD4 cell count, HIV viral load, and HIV-related laboratory monitoring rates during follow-up by calendar year. A total of 16 962 patients were included in the analysis. Patients in active follow-up increased from 695 patients at four sites in 2003 to 11,137 patients at eight sites in 2013. The proportion of patients receiving their second or third ART regimen increased over time (5% in 2003 to 29% in 2013) along with patients aged ≥50 years (8% in 2003 to 18% in 2013). Concurrently, CD4 monitoring has remained stable in recent years, whereas HIV viral load monitoring, although varied among the sites, is increasing. There have been substantial changes in the clinical and demographic characteristics of HIV-positive patients receiving ART in Asia. HIV programmes will need to anticipate the clinical care needs for their aging populations, expanded viral load monitoring, and, the eventual increase in second and third ART regimens that will lead to higher costs and more complex drug procurement needs.

Fullerenes in Biology and Medicine

Fullerenes and related carbon based derivatives have shown a growing relevance in biology and medicine, mainly due to the unique electronic and structural properties that make them excellent candidates for multiple functionalization. This review focuses on the most recent developments of fullerene derivatives for different biological applications.

A decade of HAART in Latin America: Long term outcomes among the first wave of HIV patients to receive combination therapy

BACKGROUND

In Latin America, the first wave of HIV-infected patients initiated highly active antiretroviral therapy (HAART) 10 or more years ago. Characterizing their treatment experience and corresponding outcomes across a decade of HAART may yield insights relevant to the ongoing care of such patients and those initiating HAART more recently in similar clinical settings.

METHODS

This retrospective study included adults initiating HAART before 2004 at 8 sites in Argentina, Brazil, Chile, Haiti, Honduras, and Mexico. Patient status (in care, dead, or lost to follow-up [LTFU]) was assessed at 6-month intervals for 10 years, along with CD4 count and HIV-1 viral load (VL) for patients in care.

RESULTS

4,975 patients (66% male) started HAART prior to 2004; 45% were not antiretroviral-naïve. At 1, 5, and 10 years, rates of mortality were 4.2%, 9.0%, and 13.6% respectively. LTFU rates for the same periods were 2.4%, 10.9%, and 24.2%. Among patients remaining in care at 10 years, 84.4% were estimated to have VL≤400 copies/mL (Haiti excluded) and median baseline CD4 increased from 158 to 525 cells/mm3. Only 11.4% of all patients remained on their first regimen, 12.6% were on their second, 11.5% were on their third, and 23.0% were on their fourth or subsequent regimen. Outcomes were generally better for patients who were not antiretroviral-naïve, except for viral suppression. Heterogeneity among sites was substantial.

CONCLUSIONS

Despite advanced disease and predominant use of older antiretrovirals, a large percentage of early HAART initiators in this Latin American cohort were alive and in care with sustained virologic suppression and progressive immune recovery after 10 years.

From antiretroviral therapy access to provision of third line regimens: evidence of HIV Drug resistance mutations to first and second line regimens among Ugandan adults

Background

HIV care programs in resource-limited settings have hitherto concentrated on antiretroviral therapy (ART) access, but HIV drug resistance is emerging. In a cross-sectional study of HIV-positive adults on ART for ≥6 months enrolled into a prospective cohort in Uganda, plasma HIV RNA was measured and genotyped if ≥1000 copies/ml. Identified Drug resistance mutations (DRMs) were interpreted using the Stanford database, 2009 WHO list of DRMs and the IAS 2014 update on DRMs, and examined and tabulated by ART drug classes.

Findings

Between July 2013 and August 2014, 953 individuals were enrolled, 119 (12.5%) had HIV-RNA ≥1000 copies/ml and 110 were successfully genotyped; 74 (67.3%) were on first-line and 36 (32.7%) on second-line ART regimens. The predominant HIV-1 subtypes were D (34.5%), A (33.6%) and Recombinant forms (21.8%). The commonest clinically significant major resistance mutations associated with the highest levels of reduced susceptibility or virological response to the relevant Nucleoside Reverse Transcriptase Inhibitor (NRTI) were; the Non-thymidine analogue mutations (Non-TAMS) M184V—20.7% and K65R—8.0%; and the TAMs M41L and K70R (both 8.0%). The major Non-NRTI (NNRTI) mutations were K103N—19.0%, G190A—7.0% and Y181C—6.0%. A relatively nonpolymorphic accessory mutation A98G—12.0% was also common. Seven of the 36 patients on second line ART had major Protease Inhibitor (PI) associated DRMS including; V82A—7.0%, I54V, M46I and L33I (all 5.0%). Also common were the accessory PI mutations L10I—27%, L10V—12.0% and L10F—5.0% that either reduce PI susceptibility or increase the replication of viruses containing PI-resistance mutations. Of the 7 patients with major PI DRMs, five had high level resistance to ritonavir boosted Lopinavir and Atazanavir, with Darunavir as the only susceptible PI tested.

Conclusions

In resource-limited settings, HIV care programs that have previously concentrated on ART access, should now consider availing access to routine HIV viral load monitoring, targeted HIV drug resistance testing and availability of third-line ART regimens.

Development of peptide inhibitors of HIV transmission

Treatment of HIV has long faced the challenge of high mutation rates leading to rapid development of resistance, with ongoing need to develop new methods to effectively fight the infection. Traditionally, early HIV medications were designed to inhibit RNA replication and protein production through small molecular drugs. Peptide based therapeutics are a versatile, promising field in HIV therapy, which continues to develop as we expand our understanding of key protein-protein interactions that occur in HIV replication and infection. This review begins with an introduction to HIV, followed by the biological basis of disease, current clinical management of the disease, therapeutics on the market, and finally potential avenues for improved drug development.

Fullerene Derivatives Strongly Inhibit HIV-1 Replication by Affecting Virus Maturation without Impairing Protease Activity

Three compounds (1, 2, and 3) previously reported to inhibit HIV-1 replication and/or in vitro activity of reverse transcriptase were studied, but only fullerene derivatives 1 and 2 showed strong antiviral activity on the replication of HIV-1 in human CD4(+) T cells. However, these compounds did not inhibit infection by single-round infection vesicular stomatitis virus glycoprotein G (VSV-G)-pseudotyped viruses, indicating no effect on the early steps of the viral life cycle. In contrast, analysis of single-round infection VSV-G-pseudotyped HIV-1 produced in the presence of compound 1 or 2 showed a complete lack of infectivity in human CD4(+) T cells, suggesting that the late stages of the HIV-1 life cycle were affected. Quantification of virion-associated viral RNA and p24 indicates that RNA packaging and viral production were unremarkable in these viruses. However, Gag and Gag-Pol processing was affected, as evidenced by immunoblot analysis with an anti-p24 antibody and the measurement of virion-associated reverse transcriptase activity, ratifying the effect of the fullerene derivatives on virion maturation of the HIV-1 life cycle. Surprisingly, fullerenes 1 and 2 did not inhibit HIV-1 protease in an in vitro assay at the doses that potently blocked viral infectivity, suggesting a protease-independent mechanism of action. Highlighting the potential therapeutic relevance of fullerene derivatives, these compounds block infection by HIV-1 resistant to protease and maturation inhibitors.

Improved survival in HIV treatment programmes in Asia

BACKGROUND

Antiretroviral treatment (ART) for HIV-positive patients has expanded rapidly in Asia over the last 10 years. Our study aimed to describe the time trends and risk factors for overall survival in patients receiving first-line ART in Asia.

METHODS

We included HIV-positive adult patients who initiated ART between 2003-2013 (n=16,546), from seven sites across six Asia-Pacific countries. Patient follow-up was to May 2014. We compared survival for each country and overall by time period of ART initiation using Kaplan-Meier curves. Factors associated with mortality were assessed using Cox regression, stratified by site. We also summarized first-line ART regimens, CD4⁺ T-cell count at ART initiation, and CD4⁺ T-cell and HIV viral load testing frequencies.

RESULTS

There were 880 deaths observed over 54,532 person-years of follow-up, a crude rate of 1.61 (95% CI 1.51, 1.72) per 100 person-years. Survival significantly improved in more recent years of ART initiation. The survival probability at 4 years follow-up for those initiating ART in 2003-2005 was 92.1%, 2006-2009 was 94.3% and 2010-2013 was 94.5% (P<0.001). Factors associated with higher mortality risk included initiating ART in earlier time periods, older age, male sex, injecting drug use as HIV exposure and lower pre-ART CD4⁺ T-cell count. Concurrent with improved survival was increased tenofovir use, ART initiation at higher CD4⁺ T-cell counts and greater monitoring of CD4⁺ T-cells and HIV viral load.

CONCLUSIONS

Our results suggest that HIV-positive patients from Asia have improved survival in more recent years of ART initiation. This is likely a consequence of improvements in treatment, patient management and monitoring over time.

Projecting the epidemiological effect, cost-effectiveness and transmission of HIV drug resistance in Vietnam associated with viral load monitoring strategies

OBJECTIVES

The objective of this study was to investigate the potential epidemiological impact of viral load (VL) monitoring and its cost-effectiveness in Vietnam, where transmitted HIV drug resistance (TDR) prevalence has increased from <5% to 5%-15% in the past decade.

METHODS

Using a population-based mathematical model driven by data from Vietnam, we simulated scenarios of various combinations of VL testing coverage, VL thresholds for second-line ART initiation and availability of HIV drug-resistance tests. We assessed the cost per disability-adjusted life year (DALY) averted for each scenario.

RESULTS

Projecting expected ART scale-up levels, to approximately double the number of people on ART by 2030, will lead to an estimated 18 510 cases (95% CI: 9120-34 600 cases) of TDR and 55 180 cases (95% CI: 40 540-65 900 cases) of acquired drug resistance (ADR) in the absence of VL monitoring. This projection corresponds to a TDR prevalence of 16% (95% CI: 11%-24%) and ADR of 18% (95% CI: 15%-20%). Annual or biennial VL monitoring with 30% coverage is expected to relieve 12%-31% of TDR (2260-5860 cases), 25%-59% of ADR (9620-22 650 cases), 2%-6% of HIV-related deaths (360-880 cases) and 19 270-51 400 DALYs during 2015-30. The 30% coverage of VL monitoring is estimated to cost US$4848-5154 per DALY averted. The projected additional cost for implementing this strategy is US$105-268 million over 2015-30.

CONCLUSIONS

Our study suggests that a programmatically achievable 30% coverage of VL monitoring can have considerable benefits for individuals and leads to population health benefits by reducing the overall national burden of HIV drug resistance. It is marginally cost-effective according to common willingness-to-pay thresholds.

Reasons and Risk Factors for the Initial Regimen Modification in Chinese Treatment-Naïve Patients with HIV Infection: A Retrospective Cohort Analysis

Background

To investigate the reasons and risk factors for modification of the first combined antiretroviral therapy (cART) currently used for HIV infected patients who were treatment naïve in Shanghai China.

Methods

Making a retrospective observational research on treatment naïve patients with HIV infection who initiated cART during the period of September 1st 2005---December 1st 2013. The demographic and clinical data were collected from the first visit to the time of the first regimen modification or the last visit in December 1st, 2014. The reasons of treatment modification were recorded. Survival analysis of modification was made by Kaplan-Meier curves analysis and log rank test, and a Cox multiple regression model was constructed to identify related factors of modification.

Results

A total number of the eligible participants were 3372 and 871(25.8%) patients changed their first cART regimen. The median follow up was 22 months [interquartile range (IQR) 14–39]. Among patients who modified the original regimen, drug toxicity occurred in 805(92.4%) participants and 44(5.1%) experienced treatment failure. In multiple regression analysis regimen modification was associated with patients’ age more than 40 years old (aHR 1.224, 95%CI 1.051–1.426, P = 0.010), CD4 less than 200(aHR 1.218, 95%CI 1.044–1.421, P = 0.012) and the initial regimen they received. Compared with the regimen of TDF+3TC+EFV, patients with regimen of d4T+3TC+NVP, d4T+3TC+EFV, AZT+3TC+NVP or AZT+3TC+EFV were 10.4, 8.2, 6.4, 2.5 times more likely to modify their initial regimen, respectively.

Conclusions

The main reason for the regimen switch was drug toxicity and main risk factors for regimen modification were age older than 40 years, CD4 cell counts less than 200 at baseline and regimen they received. Among the 2NRTI plus 1NNRTI regimens, the co-formulation of d4T+3TC+NVP had the highest risk for modification while the regimen of TDF+3TC+EFV was the most tolerable treatment regimen in first years’ follow up.

Beyond the bedside: A review of translational medicine in global health

Translational research is a broad field of medicine with several key phases moving from scientific discovery to bench research and the hospital bedside, followed by evidence-based practice and population-level policy and programming. Understanding these phases is crucial when it comes to preventing and treating illness, especially in global health. Communities around the world struggle with a variety of health problems that are at some times similar and at others quite different. Three major world health issues help to outline the phases of translational research: vaccines, human immunodeficiency virus and acquired immunodeficiency syndrome, and non-communicable diseases. Laboratory research has excelled in many of these areas and is struggling in a few. Where successful therapies have been discovered there are often problems with appropriate use or dissemination to groups in need. Also, many diseases would be better prevented from a population health approach. This review highlights successes and struggles in the arena of global health, from smallpox eradication to the impending epidemic of cardiovascular disease, in an attempt to illustrate of the various phases of translational research.

Simplified clinical prediction scores to target viral load testing in adults with suspected first line treatment failure in Phnom Penh, Cambodia

Background

For settings with limited laboratory capacity, 2013 World Health Organization (WHO) guidelines recommend targeted HIV-1 viral load (VL) testing to identify virological failure. We previously developed and validated a clinical prediction score (CPS) for targeted VL testing, relying on clinical, adherence and laboratory data. While outperforming the WHO failure criteria, it required substantial calculation and review of all previous laboratory tests. In response, we developed four simplified, less error-prone and broadly applicable CPS versions that can be done ‘on the spot’.

Methodology/Principal

Findings From May 2010 to June 2011, we validated the original CPS in a non-governmental hospital in Phnom Penh, Cambodia applying the CPS to adults on first-line treatment >1 year. Virological failure was defined as a single VL >1000 copies/ml. The four CPSs included CPS1 with ‘current CD4 count’ instead of %-decline-from-peak CD4; CPS2 with hemoglobin measurements removed; CPS3 having ‘decrease in CD4 count below baseline value’ removed; CPS4 was purely clinical. Score development relied on the Spiegelhalter/Knill-Jones method. Variables independently associated with virological failure with a likelihood ratio ≥1.5 or ≤0.67 were retained. CPS performance was evaluated based on the area-under-the-ROC-curve (AUROC) and 95% confidence intervals (CI). The CPSs were validated in an independent dataset. A total of 1490 individuals (56.6% female, median age: 38 years (interquartile range (IQR 33–44)); median baseline CD4 count: 94 cells/µL (IQR 28–205), median time on antiretroviral therapy 3.6 years (IQR 2.1–5.1)), were included. Forty-five 45 (3.0%) individuals had virological failure. CPS1 yielded an AUROC of 0.69 (95% CI: 0.62–0.75) in validation, CPS2 an AUROC of 0.68 (95% CI: 0.62–0.74), and CPS3, an AUROC of 0.67 (95% CI: 0.61–0.73). The purely clinical CPS4 performed poorly (AUROC-0.59; 95% CI: 0.53–0.65).

Conclusions

Simplified CPSs retained acceptable accuracy as long as current CD4 count testing was included. Ease of field application and field accuracy remains to be defined.