Superior Effectiveness of Zidovudine Compared With Tenofovir When Combined With Nevirapine-based Antiretroviral Therapy in a Large Nigerian Cohort

Antiretroviral Therapy-associated Adverse Drug Reactions and their Effects on Virologic Failure- A Retrospective Cohort Study in Nigeria

Background:

Adverse drug reactions (ADRs) associated with antiretroviral therapy (ART) can rapidly reverse the gains of ART resulting in poor health outcomes. We need an improved under-standing of specific ART-related ADRs that influence virologic outcomes.

Objective:

To investigate the frequency of clinical ADRs and assess their effect on virologic failure in patients on ART.

Method:

We described the prevalence of major clinical ADRs, and the association between specific ADRs and virologic failure in a clinic cohort of HIV-1 infected Nigerians aged ≥18 years, on first-line ART between June 2004 and February 2012. Multivariable logistic regression was run to identify predictors of virologic failure at 24 and 72 weeks of ART.

Results:

Data of 12,115 patients with a median age of 34 (interquartile range: 29-41) years, and pre-dominantly females (67%) were evaluated. Overall, 957 (7.9%) patients experienced at least one ADR during a median follow-up period of 4 years (interquartile range: 1-7). The three most prevalent ADRs were lipodystrophy (2.6%), anemia (1.9%), and skin rash (0.7%). Virologic failure rate was 36% and 34% at 24 and 72 weeks of ART, respectively. Anemia independently predicted the odds of virologic failure at 72 weeks of ART (adjusted odds ratio, 1.74; 95% CI: 1.2-2.51); adjusted for sex, age, pre-treatment CD4+ cell count, antiretroviral regimen, and medication refill adherence.

Conclusion:

Antiretroviral therapy-associated anemia increases the likelihood of late virologic failure. We recommend routine monitoring of hemoglobin levels and prompt management of anemia in all pa-tients on ART as a strategy to improve virologic success rates.

The role of point-of-care viral load monitoring in achieving the target of 90% suppression in HIV-infected patients in Nigeria: study protocol for a randomized controlled trial

Background

The Joint United Nations Programme on HIV/AIDS 90–90-90 goal envisions 90% of all people receiving antiretroviral therapy to be virally suppressed by 2020. Implied in that goal is that viral load be quantified for all patients receiving treatment, which is a challenging undertaking given the complexity and high cost of standard-of-care viral load testing methods. Recently developed point-of-care viral load testing devices offer new promise to improve access to viral load testing by bringing the test closer to the patient and also returning results faster, often same-day. While manufactures have evaluated point-of-care assays using reference panels, empiric data examining the impact of the new technology against standard-of-care monitoring in low- and middle-income settings are lacking. Our goal in this trial is to compare a point-of-care to standard-of-care viral load test on impact on various clinical outcomes as well to assess the acceptability and feasibility of using the assay in a resource-limited setting.

Methods

Using a two-arm randomized control trial design, we will enroll 794 patients from two different HIV treatment sites in Nigeria. Patients will be randomized 1:1 for point-of-care or standard-of-care viral load monitoring (397 patients per arm). Following initiation of treatment, viral load will be monitored at patients’ 6- and 12-month follow-up visits using either point-of-care or standard-of-care testing methods, based on trial assignment. The monitoring schedule will follow national treatment guidelines. The primary outcome measure in this trial is proportion of patients with viral suppression at month 12 post-initiation of treatment. The secondary outcome measures encompass acceptability, feasibility, and virologic impact variables.

Discussion

This clinical trial will provide information on the impact of using point-of-care versus standard-of-care viral load testing on patient clinical outcomes; the study will also supply data on the acceptability and feasibility of point-of-care viral load monitoring in a resource-limited setting. If this method of testing is acceptable and feasible, and also superior to standard of care, the results of the trial and the information gathered will inform future scaled implementation and further optimization of the clinic-laboratory network that is critical for monitoring achievement of the 90–90-90 goals.

Trial registration

US National Institutes of Health Clinical Trials.gov: NCT03533868. Date of Registration: 23 May 2018. Protocol Version: 10. Protocol Date: 30 March 2018.

Treatment Outcome and Adverse Events of Tenofovir Disoproxil Fumarate Based Regimens as Compared to Zidovudine Based Regimens Among People Living with HIV/AIDS: A Systematic Review and Meta-Analysis of Observational Studies

Background:

Findings from different studies report inferior clinical and virologic efficacy with TDF/3TC/NVP. But, some studies show that, there was no statistically significant difference in mortality among ZDV and TDF based regimens. The objective of this review was to systematically identify, appraise and synthesize the best available evidence on efficacy and safety of TDF based regimen as compared to ZDV based regimens.

Methods:

A three-step search strategy was used to locate published and unpublished studies. First, an initial limited search of google was undertaken followed by analysis of text words. A second extensive search was undertaken. We searched the PubMed, EMBASE, Google Scholar, Medline, and CINHAL. We did the initial search for articles on July 11-18, 2016, and updated the results on May 13, 2017.Third, the reference lists of all identified articles was searched for additional studies.

Results:

ZDV based regimens had better outcome on prevention of mortality (OR=1.31, 95%CI (1.14, 1.50), I² = 0%, Chi² = 2.51), and lower virologic failure (OR = 1.44, 95% CI [1.18, 1.76], chi² = 5.91, P= 0.003, I² =83%) while, TDF based regimens were more tolerable (OR=0.15, 95%CI (0.08, 0.30), I² = 40%, Chi² = 3.31). The difference in incidence of opportunistic infection is not significant (OR = 0.83, 95% CI [0.52, 1.32], chi² = 0.11, P= 0.42, I² =0%).

Conclusion:

There is lower mortality and lower virologic failure in ZDV group, but better safety profile among TDF based regimens.

Quantifying an Adherence Path-Specific Effect of Antiretroviral Therapy in the Nigeria PEPFAR Program

Since the early 2000s, evidence has accumulated for a significant differential effect of first-line antiretroviral therapy (ART) regimens on human immunodeficiency virus (HIV) viral load suppression. This finding was replicated in our data from the Harvard President's Emergency Plan for AIDS Relief (PEPFAR) program in Nigeria. Investigators were interested in finding the source of these differences, i.e., understanding the mechanisms through which one regimen outperforms another, particularly via adherence. This question can be naturally formulated via mediation analysis with adherence playing the role of a mediator. Existing mediation analysis results, however, have relied on an assumption of no exposure-induced confounding of the intermediate variable, and generally require an assumption of no unmeasured confounding for nonparametric identification. Both assumptions are violated by the presence of drug toxicity. In this paper, we relax these assumptions and show that certain path-specific effects remain identified under weaker conditions. We focus on the path-specific effect solely mediated by adherence and not by toxicity and propose an estimator for this effect. We illustrate with simulations and present results from a study applying the methodology to the Harvard PEPFAR data. Supplementary materials are available online.

Implication of First-Line Antiretroviral Therapy Choice on Second-Line Options

BACKGROUND

Although there are a number of studies comparing the currently recommended preferred and alternative first-line (1L) antiretroviral therapy (ART) regimens on clinical outcomes, there are limited data examining the impact of 1L regimen choice and duration of virologic failure (VF) on accumulation of drug resistance mutations (DRM). The patterns of DRM from patients failing zidovudine (AZT)-containing versus tenofovir (TDF)-containing ART were assessed to evaluate the predicted susceptibility to second-line (2L) nucleoside reverse-transcriptase inhibitor (NRTI) backbone options in the context of an ongoing programmatic setting that uses viral load (VL) monitoring.

METHODS

Paired samples from Nigerian ART patients who experienced VF and switched to 2L ART were retrospectively identified. For each sample, the human immunodeficiency virus (HIV)-1 polymerase gene was sequenced at 2 time points, and DRM was analyzed using Stanford University's HIVdb program.

RESULTS

Sequences were generated for 191 patients. At time of 2L switch, 28.2% of patients on AZT-containing regimens developed resistance to TDF, whereas only 6.8% of patients on TDF-containing 1L had mutations compromising susceptibility to AZT. In a stratified evaluation, patients with 0-6 months between tested VL samples had no difference in proportion compromised to 2L, whereas those with >6 months between samples had a statistically significant difference in proportion with compromised 2L NRTI. In multivariate analyses, patients on 1L AZT had 9.90 times higher odds of having a compromised 2L NRTI option than patients on 1L TDF.

CONCLUSIONS

In the context of constrained resources, where VL monitoring is limited, we present further evidence to support use of TDF as the preferred 1L NRTI because it allows for preservation of the recommended 2L NRTI option.

Drug Resistance and Virological Failure among HIV-Infected Patients after a Decade of Antiretroviral Treatment Expansion in Eight Provinces of China

Background

China’s National Free Antiretroviral Treatment Program (NFATP) has substantially increased the survival rate since 2002. However, the emergence of HIV drug resistance (HIVDR) limits the durability and effectiveness of antiretroviral treatment (ART) in at risk patients.

Method

A cross-sectional survey was conducted among patients having received a median of 13.9 months of ART in eight provinces in China. Demographic and clinical information was collected, and venous blood was sampled for CD4 cell counts, measurement of the HIV viral load (VL), and HIV drug resistance (HIVDR) genotyping. Possible risk factors for HIVDR were analyzed by the logistic regression model.

Results

The study included 765 patients. Among them, 65 patients (8.5%) had virological failure (VLF) defined as ≥1,000 copies/ml. Among the individuals with VLF, 64 were successful genotyped, and of these, 33 had one or more HIVDR mutations. The prevalence of HIVDR mutations among patients receiving first-line ART was 4.3% (33/765). All of the patients with HIVDR mutations were resistant to non-nucleoside transcriptase inhibitors, 81.8% were resistant to nucleoside reverse transcriptase inhibitors, and only 3% had mutations that caused resistance to protease inhibitors. Having lower ratios of drug intake in the past month and dwelling in two southwestern provinces were factors independently associated with the emergence of HIVDR.

Conclusion

Most patients receiving first-line ART treatment achieved sound virological and immunological outcomes. However, poor adherence is still a key problem, which has led to the high rate of HIVDR. It was notable that the proportion of drug resistance widely varied among the provinces. More studies are needed to focus on adherence.

Long-Term Outcomes on Antiretroviral Therapy in a Large Scale-Up Program in Nigeria

Background

While there has been a rapid global scale-up of antiretroviral therapy programs over the past decade, there are limited data on long-term outcomes from large cohorts in resource-constrained settings. Our objective in this evaluation was to measure multiple outcomes during first-line antiretroviral therapy in a large treatment program in Nigeria.

Methods

We conducted a retrospective multi-site program evaluation of adult patients (age ≥15 years) initiating antiretroviral therapy between June 2004 and February 2012 in Nigeria. The baseline characteristics of patients were described and longitudinal analyses using primary endpoints of immunologic recovery, virologic rebound, treatment failure and long-term adherence patterns were conducted.

Results

Of 70,002 patients, 65.2% were female and median age was 35 (IQR: 29–41) years; 54.7% were started on a zidovudine-containing and 40% on a tenofovir-containing first-line regimen. Median CD4+ cell counts for the cohort started at 149 cells/mm³ (IQR: 78–220) and increased over duration of ART. Of the 70,002 patients, 1.8% were reported as having died, 30.1% were lost to follow-up, and 0.1% withdrew from treatment. Overall, of those patients retained and with viral load data, 85.4% achieved viral suppression, with 69.3% achieving suppression by month 6. Of 30,792 patients evaluated for virologic failure, 24.4% met criteria for failure and of 45,130 evaluated for immunologic failure, 34.0% met criteria for immunologic failure, with immunologic criteria poorly predicting virologic failure. In adjusted analyses, older age, ART regimen, lower CD4+ cell count, higher viral load, and inadequate adherence were all predictors of virologic failure. Predictors of immunologic failure differed slightly, with age no longer predictive, but female sex as protective; additionally, higher baseline CD4+ cell count was also predictive of failure. Evaluation of long-term adherence patterns revealed that the majority of patients retained through 84 months maintained ≥95% adherence.

Conclusion

While improved access to HIV care and treatment remains a challenge in Nigeria, our study shows that a high quality of care was achieved as evidenced by strong long-term clinical, immunologic and virologic outcomes.