Antiretroviral therapies in women after single-dose nevirapine exposure

Incidence and Predictors of Pregnancy in Women Enrolled in Large Multinational HIV Treatment Trials of the AIDS Clinical Trials Group

OBJECTIVES

Women are under-represented in clinical trials and must often commit to using contraception to enroll. We sought to determine the incidence and predictors of pregnancy in women participating in HIV treatment trials.

DESIGN

Individual participant data meta-analysis.

METHODS

We included data from multicountry HIV treatment trials conducted during the period 2005-2019 by the AIDS Clinical Trials Group that included females with HIV who were of reproductive potential, did not intend to become pregnant, and agreed to use effective contraception during study treatment. We extracted data from all female participants of age 18-55 years, including occurrence and dates of pregnancy on-study; however, only a few incident pregnancy predictor variables were available for analysis.

RESULTS

One thousand six hundred twenty-six women from 4 trials were included. Over a median of 28 months (6461 person-years) of follow-up, 143 (9%) women became pregnant, for an overall incidence of 2.2 pregnancies/100 person-years (range 0.5-3/100 person-years, by study). In multivariable analysis including baseline age, type of regimen, and country as predictor variables, younger age remained the strongest predictor of incident pregnancy ( P < 0.0001 adjusted for country and antiretroviral treatment regimen). CD4 and HIV-1 RNA were not associated with pregnancy incidence.

CONCLUSIONS

Pregnancy incidence was 2.2/100 person-years in female participants of HIV treatment trials. Rather than leading to exclusion of young women from trials, this finding should prompt appropriate adaptations in study design and analysis for earlier generation of pregnancy safety information for drugs.

Clinical Presentation, Treatment Response, and Virology Outcomes of Women Who Seroconverted in the Dapivirine Vaginal Ring Trials-The Ring Study and DREAM

BACKGROUND

Participants with human immunodeficiency virus (HIV) seroconversion in The Ring Study, a phase 3 trial of dapivirine vaginal ring (DVR), or in the open-label extension trial dapivirine ring extended access and monitoring (DREAM) were offered enrollment in an observational cohort study (IPM 007) to assess clinical presentation and response to antiretroviral therapy (ART).

METHODS

Participants' HIV infection was managed at local treatment clinics according to national treatment guidelines. IPM 007 study visits occurred 3 and 6 months after enrollment and every 6 months thereafter. Assessments included plasma HIV-1 RNA, CD4+ T-cell counts, and recording of HIV/AIDS-associated events and antiretroviral use. Post hoc virology analyses were performed for participants identified with virologic failure.

RESULTS

One hundred fifty-one of 179 eligible participants (84.4%) enrolled into IPM 007; 103 had previously received the DVR in the Ring or DREAM studies, and 48 had received placebo in The Ring Study. HIV-1 RNA and CD4+ T-cell counts after 12 months' follow-up were similar for participants who used the DVR in The Ring Study and DREAM, compared to those who received placebo. Of the 78 participants with a study visit approximately 6 months after ART initiation, 59 (75.6%) had HIV-1 RNA <40 copies/mL (The Ring Study: placebo: 13/23 [56.5%]; DVR: 32/39 [82.1%]; DREAM [DVR]: 14/16 [87.5%]). Post hoc virology analysis indicated that genotypic patterns observed at virologic failure were as expected of a nonnucleoside reverse transcriptase inhibitor (NNRTI)-based regimen.

CONCLUSIONS

Seroconversion during DVR use did not negatively affect clinical presentation or treatment outcome. Mutation patterns at virologic failure were in line with individuals failing an NNRTI-based regimen.

CLINICAL TRIALS REGISTRATION

NCT01618058.

Hepatitis B surface antigen and hepatitis B RNA changes in HIV/hepatitis B virus co-infected participants receiving hepatitis B virus-active antiretroviral therapy

INTRODUCTION

With advances in hepatitis B virus (HBV) therapies, there is a need to identify serum biomarkers that assess the HBV covalently closed circular DNA (cccDNA) reservoir and predict functional cure in HIV/HBV co-infection.

METHODS

In this retrospective study, combining samples from HIV/HBV co-infected participants enrolled in two ACTG interventional trials, proportions achieving HBsAg less than 0.05 log10 IU/ml and HBV RNA less than log10 1.65 U/ml or not detected (LLoQ/NEG) in response to DUAL [tenofovir TDF+emtricitabine (FTC)] vs. MONO [FTC or lamivudine (3TC)] HBV-active ART, were measured. Predictors of qHBsAg less than 0.05 log10 IU/ml were evaluated in logistic regression models.

RESULTS

There were 88 participants [58% women, median age 34; 47 on DUAL vs. 41 on MONO HBV-active ART]. Twenty-one percent achieved HBsAg less than 0.05 log10 IU/ml (30% DUAL vs. 10% MONO). Time to HBsAg less than 0.05 log10 IU/ml was lower (P  = 0.02) and the odds of achieving HBsAg less than 0.05 log10 IU/ml were higher (P = 0.07) in DUAL participants. HBV RNA became less than LLoQ/NEG in 47% (DUAL 60% vs. MONO 33%). qHBsAg less than 3 log10 IU/ml was the strongest predictor of HBsAg less than 0.05 log10 IU/ml.

CONCLUSION

This study supports current recommendations of TDF-based DUAL-HBV active ART for initial use in HIV/HBV co-infection. HBV RNA could be a useful marker of treatment response in HIV/HBV co-infected patients on HBV-active ART.

Nevirapine hair and plasma concentrations and HIV-1 viral suppression among HIV infected ante-partum and post-partum women attended in a mother and child prevention program in Maputo city, Mozambique

INTRODUCTION

Prevention of mother to child transmission of HIV (PMTCT) is frequently challenged by irregular access to more effective anti-retroviral therapy. Nevirapine single dose (sdNVP), sdNVP+AZT+3TC for MTCT prophylaxis and NVP+ AZT+3TC for treatment and PMTCT were withdrawn due to low genetic resistance barrier and low efficacy. However current PMTCT lines in Mozambique include DTG+3TC+TDF, TDF+3TC+EFV, DTG +ABC+3TC, and AZT + NVP syrup prophylaxis for exposed babies. We assessed NVP hair and plasma concentrations and association with HIV-1RNA suppression among HIV+ ante-partum and post-partum women under PMTCT in Maputo, Mozambique.

METHODS

From December 2013 to November 2014, prospectively were enrolled 200 HIV+ ante-partum women on 200mg nevirapine and zidovudine 300 plus lamivudine 150mg twice daily at least with 3 months treatment and seen again at 24 weeks post-partum. Self-reported pill-taking adherence, NVP concentrations in hair, plasma, hemoglobin, CD4 cell count, HIV-1 RNA load was evaluated. NVP concentration in hair and plasma was analyzed as categorical quartile variable based on better data fit. NVP concentration was set between ≤3.77 ng/ml in plasma and ≤17,20 ng/mg in hair in quartile one to ≥5.36 ng/ml in plasma and ≥53.21 ng/mg in hair in quartile four. Logistic regression models for repeated measures were calculated. Following the World Health Organization (WHO) guidelines we set viral suppression at HIV-1RNA < 1000 c/mL. Outcome was HIV-1 RNA<1000 copies/ml. Predictor was NVP concentration in hair categorized in quartiles.

RESULTS

In total 369 person-visits (median of 1.85) were recorded. Self-reported adherence was 98% (IQR 97-100%) at ante-partum. In 25% person visits, NVP concentrations were within therapeutic levels (3.77 ng/ml to 5.35 ng/ml) in plasma and (17.20 ng/mg to 53.20 ng/mg) in hair. In 50% person visits NVP concentrations were above 5.36 ng/ml in plasm and 53.21 ng/mg in hair. HIV-1 RNA suppression was found in 34.7% of women with two viral loads, one at enrollment and another in post-partum. Odds of HIV-1 RNA suppression in quartile 4, was about 6 times higher than in quartile 1 (p-value = 0.006) for NVP hair concentration and 7 times for NVP plasma concentration (p-value = 0.012).

CONCLUSIONS

The study results alert for potential low efficacy of current PMTCT drug regimens in use in Mozambique. Affordable means for individual monitoring adherence, ART plasma and hair levels, drug resistant and HIV-1 RNA levels monitoring are recommended for prompt identification of inadequate drug regimens exposure patterns and adjust accordingly.

Prevalence and risk of residual viremia after ART in low- and middle-income countries: A cross-sectional study

In order to design effective strategies to eradicate the HIV, an understanding of persistent viral reservoirs is needed. Many studies have demonstrated HIV residual viremia prevalence in high income countries, data from low- and middle-income countries (LMIC) are limited. We assessed the prevalence, and factors associated with residual viremia in people with HIV (PWH), who were virally-suppressed on antiretroviral therapy (ART) in LMIC. We also compared residual viremia prevalence between the LMIC and US.This is a cross-sectional, retrospective study that utilized stored specimen samples from the AIDS clinical trials group (ACTG) studies A5175 and A5208. The last available sample among participants with plasma HIV RNA < 400 copies/mL for ≥3 years were tested by the HIV molecular and monitoring core gag (HMMCgag) single copy assay (SCA). Residual viremia was defined as detectable if ≥1 copy/mL. Spearman's correlation and multivariable stepwise logistic regression were used to assess associations of various factors with SCA.A total of 320 participants, 246 (77%) from LMIC and 74 (23%) from US, were analyzed. Median (IQR) age was 33 (2840) years; baseline CD4 166 (88,230) cells/mm3; HIV RNA 5.0 (4.5, 5.3) log10 copies/mL; duration of viral suppression 3.4 (3.1, 4.0) years and 48% were male. In 85 participants with information available, 53% were subtype C, 42% subtype B and 5% other subtypes. Overall prevalence of residual viremia was 57% [95% CI, 52-63] with 51% [40-63] in US and 59% [53-65] in LMIC. Among participants with detectable SCA, the median (IQR) HIV RNA was 3.8 (2.2, 8.1) copies/mL. The multivariable model conducted in LMIC participants showed that higher baseline HIV RNA was associated with detectable residual RNA (OR 2.9, 95% CI 1.8, 4.6 for every log10 increase, P < .001). After including both US and LMIC in the final model, baseline HIV RNA remained significant. No difference in SCA detestability was found between US and LMIC sites (OR 1.1 [0.6, 2.0], P = .72) after adjusting for baseline RNA and parent study.The prevalence of residual viremia between both groups were not different and more than half of the participants had detectable viremia. Higher baseline HIV RNA was independently associated with residual viremia.

Factors Affecting Virological Outcome When First-Line Antiretroviral Therapy Is Reintroduced After Unplanned Interruption

There is no guideline concerning choice of antiretroviral therapy (ART) for HIV-infected patients after unplanned interruption. We conducted a retrospective cohort study of HIV-infected patients reintroduced to first-line ART after having unplanned interruption for at least 1 month. Viral load was evaluated at 6 to 18 months after the reintroduction. There were 100 patients included in our study, and 55 of them achieved virological success. History of single interruption (adjusted odds ratio [aOR] 5.51%, 95% confidence interval [CI] 1.82-16.68, P = .003) and CD4 count ≥200 cell/mm³ at the time of reintroduction (aOR 4.33, 95% CI 1.14-16.39, P = .031) increased likelihood to achieve virological success.

Attaining 95-95-95 through Implementation Science: 15 Years of Insights and Best Practices from the Walter Reed Army Institute of Research's Implementation of the U.S. President's Emergency Plan for AIDS Relief

The Walter Reed Army Institute of Research (WRAIR) supports more than 350,000 people on lifesaving HIV treatment in Kenya, Nigeria, Tanzania, and Uganda through funding from the U.S. President’s Emergency Plan for AIDS Relief (PEPFAR). Here, we review and synthesize the range of impacts WRAIR’s implementation science portfolio has had on PEPFAR service delivery for military and civilian populations since 2003. We also explore how investments in implementation science create institutional synergies within the U.S. Department of Defense, contributing to broad global health engagements and improving health outcomes for populations served. Finally, we discuss WRAIR’s contributions to PEPFAR priorities through use of data to drive and improve programming in real time in the era of HIV epidemic control and public health messaging that includes prevention, the 95-95-95 goals, and comorbidities.

Clinical Impact of Pretreatment Human Immunodeficiency Virus Drug Resistance in People Initiating Nonnucleoside Reverse Transcriptase Inhibitor-Containing Antiretroviral Therapy: A Systematic Review and Meta-analysis

Background

Increased access to antiretroviral therapy (ART) has resulted in rising levels of pretreatment human immunodeficiency virus drug resistance (PDR). This is the first systematic review and meta-analysis to assess the impact of PDR on treatment outcomes among people initiating nonnucleoside reverse transcriptase inhibitor (NNRTI)–based ART, including the combination of efavirenz (EFV), tenofovir (TDF), and lamivudine or emtricitabine (XTC).

Methods

We systematically reviewed studies and conference proceedings comparing treatment outcomes in populations initiating NNRTI-based ART with and without PDR. We conducted subgroup analyses by regimen: (1) NNRTIs + 2 nucleoside reverse transcriptase inhibitors (NRTIs), (2) EFV + 2 NRTIs, or (3) EFV/TDF/XTC; by population (children vs adults); and by definition of resistance (PDR vs NNRTI PDR).

Results

Among 6197 studies screened, 32 were analyzed (31 441 patients). We found that individuals with PDR initiating NNRTIs across all the subgroups had increased risk of virological failure compared to those without PDR. Risk of acquisition of new resistance mutations and ART switch was also higher in people with PDR.

Conclusions

This review shows poorer treatment outcomes in the presence of PDR, supporting the World Health Organization’s recommendation to avoid using NNRTIs in countries where levels of PDR are high.

Evaluation of the management of pretreatment HIV drug resistance by oligonucleotide ligation assay: a randomised controlled trial

BACKGROUND

Although experts have recommended testing for pretreatment drug resistance (PDR) before antiretroviral therapy (ART) initiation, there is little evidence to support its implementation. We aimed to establish whether an inexpensive point mutation assay can improve virological suppression by identifying PDR to guide drug selection for ART in a lower-middle income country.

METHODS

Investigators did an open-label, randomised controlled trial at three HIV treatment sites in Kenya: two in Nairobi and one in rural Maseno. Individuals (aged ≥2 years) were eligible to participate if they were confirmed HIV-seropositive, qualified for first-line ART, planned to reside in the area for more than 1 year, and provided informed consent. We randomly assigned participants (1:1) to either PDR testing by oligonucleotide ligation assay (OLA) to guide selection of ART or to standard of care, which did not include OLA testing. The OLA-guided therapy group had pre-ART peripheral blood mononuclear cells evaluated for drug resistance to non-nucleoside reverse transcriptase inhibitor (NNRTI) at codons Lys103Asn, Tyr181Cys, Gly190Ala, and to lamivudine at Met184Val, and when at least one drug-resistant codon was detected in a participant's pre-ART specimen, clinicians were directed to prescribe protease inhibitor-based second-line ART. Those without detected resistance and those who were randomised to standard of care received NNRTI-based first-line ART. The primary outcome was plasma HIV-1 RNA of at least 400 copies per mL at 4, 8, or 12 months after ART initiation, which defined virological failure, assessed in all participants who received treatment (data were censored for those lost-to-follow-up or who died). The study has been completed and is registered with ClinicalTrials.gov, NCT01898754.

FINDINGS

We screened 1198 participants between May 28, 2013, and Nov 4, 2014, of whom 991 (83%) were enrolled (492 received OLA and 495 received standard of care; four did not begin treatment). 93 participants (prevalence 9·4%) had PDR (95% CI 7·7-11·4). 34 (8·5%) of 400 participants in the OLA group had virological failure at month 12 of ART (95% CI 6·0-11·7) compared with 39 (9·7%) of 402 (7·0-13·0) in the standard-of-care group (log-rank p=0·26). Among participants with PDR, virological failure was lower in the OLA-guided therapy group than in the standard-of-care group: five (14%) of 35 compared with 13 (50%) of 26; p=0·0020). Among those prescribed NNRTI-based ART, participants given efavirenz were less likely to have virological failure than were those receiving nevirapine (odds ratio 0·37, 95% CI 0·22-0·62; p<0·0001). The OLA-guided therapy group had 39 serious non-lethal adverse events and 34 deaths. The standard-of-care group had 34 severe adverse events and 43 deaths, differences that were not significant. Adverse events judged to potentially be due to ART were few and similar between groups, with 17 (16%) in the OLA-guided therapy group and 16 (16%) in the standard-of-care group (p=0·90).

INTERPRETATION

Our finding that OLA testing for PDR reduced virological failure in only those with specific PDR mutations suggests that PDR poses less of a risk for virological failure than that predicted by past prevalence estimates, and that the value of PDR testing to reduce virological failure should be assessed for antiretroviral treatment regimens.

FUNDING

US National Institutes of Health.

Protease Inhibitors or NNRTIs as First-Line HIV-1 Treatment in West Africa (PIONA): A Randomized Controlled Trial

BACKGROUND

Nonnucleoside reverse transcriptase inhibitors (NNRTIs) are recommended as part of first-line treatment for HIV-1 in Africa. However, NNRTI-based regimens are more prone to resistance development than protease inhibitors (PIs) in a context in which drug interruptions are frequent. The aim of this study was to compare the efficacy and tolerability of NNRTIs with PIs in HIV-1-infected patients in Guinea-Bissau.

METHODS

This open-label randomized, 2-arm superiority trial compared the use of 2 NRTIs plus either one NNRTI (efavirenz or nevirapine) or one PI (lopinavir/ritonavir) in treatment-naive HIV-1-infected adults in the Bissau HIV Cohort (ClinicalTrials.gov, NCT0019235). The primary endpoint was HIV-1 RNA <400 copies per milliliter after 12 months of treatment.

RESULTS

Between May 5, 2011, and April 26, 2013, 400 patients were included in the study. In an intention-to-treat analysis, the proportions of patients with viral suppression were similar in the NNRTI [65/197 (33.0%)] and PI [68/203 (33.5%)] arms (P = 0.92). No PI resistance was detected, but high-level NNRTI resistance was seen in 17/30 (56.7%) of NNRTI vs. 3/26 (11.5%) of PI-treated patients, P < 0.01. After 1 year of follow-up, 65 patients died (16.3%) and 93 were lost to follow-up (23.3%). There was no difference in mortality (hazard ratio 0.84, 95% confidence interval: 0.51 to 1.36) or frequency of clinical adverse events between treatment arms [NNRTI: 73/197 (37.1%); and PI: 69/203 (34.0%); P = 0.52].

CONCLUSIONS

In patients at an HIV clinic in Guinea-Bissau, treatment with PIs led to less development of resistance compared with NNRTIs but was not superior in terms of viral suppression, CD4 cell increment, mortality, or severe adverse events.

Linked dual-class HIV resistance mutations are associated with treatment failure

We hypothesized that HIV-1 with dual-class but not single-class drug resistance mutations linked on the same viral genome, present in the virus population before initiation of antiretroviral therapy (ART), would be associated with failure of ART to suppress viremia. To test this hypothesis, we utilized an ultrasensitive single-genome sequencing assay that detects rare HIV-1 variants with linked drug resistance mutations (DRMs). A case (ART failure) control (nonfailure) study was designed to assess whether linkage of DRMs in pre-ART plasma samples was associated with treatment outcome in the nevirapine/tenofovir/emtricitabine arm of the AIDS Clinical Trials Group A5208/Optimal Combined Therapy After Nevirapine Exposure (OCTANE) Trial 1 among women who had received prior single-dose nevirapine. Ultrasensitive single-genome sequencing revealed a significant association between pre-ART HIV variants with DRMs to 2 drug classes linked on the same genome (dual class) and failure of combination ART with 3 drugs to suppress viremia. In contrast, linked, single-class DRMs were not associated with ART failure. We conclude that linked dual-class DRMs present before the initiation of ART are associated with ART failure, whereas linked single-class DRMs are not.

Risks and Benefits of Dolutegravir- and Efavirenz-Based Strategies for South African Women With HIV of Child-Bearing Potential: A Modeling Study

BACKGROUND

Dolutegravir is superior to efavirenz for HIV antiretroviral therapy (ART) but may be associated with an increased risk for neural tube defects (NTDs) in newborns if used by women at conception.

OBJECTIVE

To project clinical outcomes of ART policies for women of child-bearing potential in South Africa.

DESIGN

Model of 3 strategies: efavirenz for all women of child-bearing potential (EFV), dolutegravir for all women of child-bearing potential (DTG), or World Health Organization (WHO)-recommended efavirenz without contraception or dolutegravir with contraception (WHO approach).

DATA SOURCES

Published data on NTD risks (efavirenz, 0.05%; dolutegravir, 0.67% [Tsepamo study]), 48-week ART efficacy with initiation (efavirenz, 60% to 91%; dolutegravir, 96%), and age-stratified fertility rates (2 to 139 per 1000 women).

TARGET POPULATION

3.1 million South African women with HIV (aged 15 to 49 years) starting or continuing first-line ART, and their children.

TIME HORIZON

5 years.

PERSPECTIVE

Societal.

INTERVENTION

EFV, DTG, and WHO approach.

OUTCOME MEASURES

Deaths among women and children, sexual and pediatric HIV transmissions, and NTDs.

RESULTS OF BASE-CASE ANALYSIS

Compared with EFV, DTG averted 13 700 women's deaths (0.44% decrease) and 57 700 sexual HIV transmissions, but increased total pediatric deaths by 4400 because of more NTDs. The WHO approach offered some benefits compared with EFV, averting 4900 women's deaths and 20 500 sexual transmissions while adding 300 pediatric deaths. Overall, combined deaths among women and children were lowest with DTG (358 000 deaths) compared with the WHO approach (362 800 deaths) or EFV (367 300 deaths).

RESULTS OF SENSITIVITY ANALYSIS

Women's deaths averted with DTG exceeded pediatric deaths added with EFV unless dolutegravir-associated NTD risk was 1.5% or greater.

LIMITATION

Uncertainty in NTD risks and dolutegravir efficacy in resource-limited settings, each examined in sensitivity analyses.

CONCLUSION

Although NTD risks may be higher with dolutegravir than efavirenz, dolutegravir will lead to many fewer deaths among women, as well as fewer overall HIV transmissions. These results argue against a uniform policy of avoiding dolutegravir in women of child-bearing potential.

PRIMARY FUNDING SOURCE

National Institutes of Health, National Institute of Allergy and Infectious Diseases and Eunice Kennedy Shriver National Institute of Child Health and Human Development; Massachusetts General Hospital; and Harvard University Center for AIDS Research.

Pregnancy outcomes among HIV-infected women who conceived on antiretroviral therapy

As antiretroviral therapy (ART) expands in resource-limited settings, understanding the impact of ART on pregnancy outcomes is critical. We analyzed women who became pregnant on ART while enrolled in a clinical trial (HPTN 052, ACTG A5208, and ACTG A5175); the majority of women were from Africa, with a median age of 29 years. Eligible women were on ART at conception and had a documented date of a last menstrual period and a pregnancy outcome. The primary outcome was non-live birth (stillbirth; spontaneous abortion; elective termination; or ectopic pregnancy) versus live birth. Preterm birth (<37 weeks completed gestation) was a secondary outcome. We used Cox proportional hazards regression models with time-varying covariates. 359 women became pregnant, of whom 253 (70%) met inclusion criteria: 127 (50%) were on NNRTI-based ART, 118 (47%) on PI-based ART, and 8 (3%) on 3-NRTIs at conception. There were 160 (63%) live births (76 term and 84 preterm), 11 (4%) stillbirths, 51 (20%) spontaneous abortions, 28 (11%) elective terminations, and 3 (1%) ectopic pregnancies. In multivariable analysis adjusted for region, parent study, and pre-pregnancy ART class, only older age was associated with increased hazard of preterm birth [HR: 2.49 for age 25-30 years; 95% CI: 1.18-5.26; p = 0.017]. Women conceiving on ART had high rates of preterm birth and other adverse pregnancy outcomes. Despite the benefits of ART, studies designed to investigate the effects of preconception ART on pregnancy outcomes are needed.

The World Health Organization's Response to Emerging Human Immunodeficiency Virus Drug Resistance and a Call for Global Action

The global community, including the World Health Organization (WHO), has committed to ending the AIDS epidemic and to ensuring that 90% of people living with human immunodeficiency virus (HIV) are diagnosed, 90% start treatment, and 90% achieve and maintain virological suppression. The emergence of HIV drug resistance (HIVDR) as antiretroviral treatment programs expand could preclude the 90-90-90 targets adopted by the United Nations General Assembly at the High-Level Meeting on Ending AIDS from being achieved. The Global Action Plan on HIVDR is a call for collective action grounded on normative guidance providing a standardized and robust approach to monitoring, preventing, and responding to HIVDR over the next 5 years (2017-2021). WHO is committed to supporting country, global, regional, and national partners to implement and monitor the progress of the Global Action Plan. This article outlines the key components of WHO's strategy to tackle HIVDR and the role the organization takes in leading the global response to HIVDR.

Effect of Lopinavir and Nevirapine Concentrations on Viral Outcomes in Protease Inhibitor-experienced HIV-infected Children

BACKGROUND

Adequate exposure to antiretroviral drugs is necessary to achieve and sustain viral suppression. However, the target antiretroviral concentrations associated with long-term viral suppression have not been adequately defined in children. We assessed the relationship between plasma lopinavir or nevirapine concentrations and the risk of subsequent viremia in children initially suppressed on antiretroviral therapy.

METHODS

After an induction phase of antiretroviral treatment, 195 children with viral suppression (viral load ≤400 copies/mL) were randomized to continue a lopinavir/ritonavir-based regimen or to switch to a nevirapine-based regimen (together with lamivudine and stavudine). Viral load and lopinavir or nevirapine concentrations were measured at clinic visits 4, 8, 12, 16, 20, 24, 36, 52, 64 and 76 weeks post randomization. Cox multiple failure event models were used to estimate the effects of drug concentrations on the hazard of viremia (viral load >50 copies/mL) RESULTS:: At randomization, the median (interquartile range) age, CD4 T-Lymphocyte percentage, weight-for-age and weight-for-height z scores were 19 (16-24) months, 29% (23-37), -0.6 (-1.3 to 0.2) and -3.2 (-4.1 to -2.1), respectively. The proportion of children with viral load 51-400 copies/mL at randomization was 43%. The hazard of subsequent viremia during follow-up was increased for lopinavir concentrations <1 versus ≥1 mg/L [adjusted hazard ratio 0.62 (95% confidence interval, 0.40-0.94)] and for children with viral loads 51-400 copies/mL at randomization. Nevirapine concentrations were not significantly associated with subsequent viremia.

CONCLUSIONS

Plasma lopinavir concentrations predicted viral outcomes in children receiving lopinavir-based antiretroviral therapy. Our findings support a minimum target concentration of ≥1 mg/L of lopinavir to ensure sustained viral suppression.

Deep sequencing for HIV-1 clinical management

The emerging HIV-1 resistance epidemic is threatening the impressive global advances in HIV-1 infection treatment and prevention achieved in the last decade. Next-generation sequencing is improving our ability to understand, diagnose and prevent HIV-1 resistance, being increasingly cost-effective and more accessible. However, NGS still faces a number of limitations that need to be addressed to enable its widespread use. Here, we will review the main NGS platforms available for HIV-1 diagnosis, the factors affecting the clinical utility of NGS testing and the evidence supporting -or not- ultrasensitive genotyping over Sanger sequencing for routine HIV-1 diagnosis. Now that global HIV-1 eradication might be within our reach, making NGS accessible also to LMICs has become a priority. Reductions in sequencing costs, particularly in library preparation, and accessibility to low-cost, robust but simplified automated bioinformatic analyses of NGS data will remain essential to end the HIV-1 pandemic.

Nonnucleoside Reverse-transcriptase Inhibitor- vs Ritonavir-boosted Protease Inhibitor-based Regimens for Initial Treatment of HIV Infection: A Systematic Review and Metaanalysis of Randomized Trials

BACKGROUND

Previous studies suggest that nonnucleoside reverse-transcriptase inhibitors (NNRTIs) cause faster virologic suppression, while ritonavir-boosted protease inhibitors (PI/r) recover more CD4 cells. However, individual trials have not been powered to compare clinical outcomes.

METHODS

We searched databases to identify randomized trials that compared NNRTI- vs PI/r-based initial therapy. A metaanalysis calculated risk ratios (RRs) or mean differences (MDs), as appropriate. Primary outcome was death or progression to AIDS. Secondary outcomes were death, progression to AIDS, and treatment discontinuation. We calculated RR of virologic suppression and MD for an increase in CD4 cells at week 48.

RESULTS

We included 29 trials with 9047 participants. Death or progression to AIDS occurred in 226 participants in the NNRTI arm and in 221 in the PI/r arm (RR, 1.03; 95% confidence interval, .87-1.22; 12 trials; n = 3825), death in 205 participants in the NNRTI arm vs 198 in the PI/r arm (1.04; 0.86-1.25; 22 trials; n = 8311), and progression to AIDS in 140 participants in the NNRTI arm vs 144 in the PI/r arm (1.00; 0.80-1.25; 13 trials; n = 4740). Overall treatment discontinuation (1.12; 0.93-1.35; 24 trials; n = 8249) and from toxicity (1.21; 0.87-1.68; 21 trials; n = 6195) were comparable, but discontinuation due to virologic failure was more common with NNRTI (1.58; 0.91-2.74; 17 trials; n = 5371). At week 48, there was no difference between NNRTI and PI/r in virologic suppression (RR, 1.03; 0.98-1.09) or CD4(+) recovery (MD, -4.7 cells; -14.2 to 4.8).

CONCLUSIONS

We found no difference in clinical and viro-immunologic outcomes between NNRTI- and PI/r-based therapy.

Low-Frequency Drug Resistance in HIV-Infected Ugandans on Antiretroviral Treatment Is Associated with Regimen Failure

Most patients failing antiretroviral treatment in Uganda continue to fail their treatment regimen even if a dominant drug-resistant HIV-1 genotype is not detected. In a recent retrospective study, we observed that approximately 30% of HIV-infected individuals in the Joint Clinical Research Centre (Kampala, Uganda) experienced virologic failure with a susceptible HIV-1 genotype based on standard Sanger sequencing. Selection of minority drug-resistant HIV-1 variants (not detectable by Sanger sequencing) under antiretroviral therapy pressure can lead to a shift in the viral quasispecies distribution, becoming dominant members of the virus population and eventually causing treatment failure. Here, we used a novel HIV-1 genotyping assay based on deep sequencing (DeepGen) to quantify low-level drug-resistant HIV-1 variants in 33 patients failing a first-line antiretroviral treatment regimen in the absence of drug-resistant mutations, as screened by standard population-based Sanger sequencing. Using this sensitive assay, we observed that 64% (21/33) of these individuals had low-frequency (or minority) drug-resistant variants in the intrapatient HIV-1 population, which correlated with treatment failure. Moreover, the presence of these minority HIV-1 variants was associated with higher intrapatient HIV-1 diversity, suggesting a dynamic selection or fading of drug-resistant HIV-1 variants from the viral quasispecies in the presence or absence of drug pressure, respectively. This study identified low-frequency HIV drug resistance mutations by deep sequencing in Ugandan patients failing antiretroviral treatment but lacking dominant drug resistance mutations as determined by Sanger sequencing methods. We showed that these low-abundance drug-resistant viruses could have significant consequences for clinical outcomes, especially if treatment is not modified based on a susceptible HIV-1 genotype by Sanger sequencing. Therefore, we propose to make clinical decisions using more sensitive methods to detect minority HIV-1 variants.

A study of antiretroviral resistance patterns in treatment experienced and naive human immunodeficiency virus infected-patients

BACKGROUND

About 10% of the patients had surveillance drug-related mutations for nonnucleoside reverse transcriptase inhibitors (NNRTIs) and protease inhibitors (PIs) in an Indian study. It was also reported that resistance was maximum for nucleoside reverse transcriptase inhibitors (NRTIs) and minimum for PIs.

METHODS

The present study was a cross-sectional assessment of 21 human immunodeficiency virus (HIV)-infected individuals attending a HIV care center in a tertiary care center in Mumbai, Maharashtra, India. All HIV-infected individuals included in the present analysis were tested for CD4 count, viral load, and resistance to antiretrovirals (ARVs).

RESULTS

A total of 13 male and 8 female were included in the present analysis. Of these, 18 were treatment naive and three were treatment experienced patients. In treatment-naive patients, the proportion of high-level resistance (HLR) was 2% for NRTIs, 5% for PIs, and 11% for NNRTIs. In treatment-naive patients, high susceptibility was observed for darunavir (89%) followed by lopinavir (72%) and fosamprenavir (67%) among PIs. Similarly, susceptibility was high for NRTIs lamivudine (94%), emtricitabine (94%), and tenofovir (89%). However, we found HLR for nevirapine (39%) even in treatment-naive patients.

CONCLUSIONS

The proportion of HLR was relatively low for PIs and NRTIs, compared with NNRTIs in treatment-naive patients. We also reported a high correlation in resistance patterns among drugs belonging to the same group. Thus, it may be useful to conduct ARV resistance even in newly infected HIV patients and those receiving medications for the first time.

The Global Health Impact Index: Promoting Global Health

Millions of people cannot access essential medicines they need for deadly diseases like malaria, tuberculosis (TB) and HIV/AIDS. There is good information on the need for drugs for these diseases but until now, no global estimate of the impact drugs are having on this burden. This paper presents a model measuring companies' key malaria, TB and HIV/AIDS drugs' consequences for global health (global-health-impact.org). It aggregates drugs' impacts in several ways-by disease, country and originator-company. The methodology can be extended across diseases as well as drugs to provide a more extensive picture of the impact companies' drugs are having on the global burden of disease. The study suggests that key malaria, TB and HIV/AIDS drugs are, together, ameliorating about 37% of the global burden of these diseases and Sanofi, Novartis, and Pfizer's drugs are having the largest effect on this burden. Moreover, drug impacts vary widely across countries. This index provides important information for policy makers, pharmaceutical companies, countries, and other stake-holders that can help increase access to essential medicines.

Randomized noninferiority trial of two maternal single-dose nevirapine-sparing regimens to prevent perinatal HIV in Thailand

OBJECTIVES

Perinatal single-dose nevirapine (sdNVP) selects for resistance mutations. The objective of this trial was to compare two maternal sdNVP-sparing regimens with standard zidovudine (ZDV)/sdNVP prophylaxis.

DESIGN

PHPT-5 was a randomized, partially double-blind placebo-controlled, noninferiority trial in Thailand (NCT00409591). Study participants were women with CD4 of at least 250 cells/μl and their infants.

METHODS

All women received ZDV from 28 weeks' gestation and their newborn infants for one week. Women were also randomized to receive NVP-NVP (reference): maternal intrapartum sdNVP with a 7-day 'tail' of ZDV along with lamivudine, and infant NVP (one dose immediately, another 48 h later); infant-only NVP: maternal placebos for sdNVP and the 'tail', with infant NVP; LPV/r: maternal LPV/r starting at 28 weeks. Infants were formula-fed. HIV-diagnosis was determined by DNA-PCR.

RESULTS

Four-hundred and thirty-five women were randomized between January 2009 and September 2010. Accrual was terminated prematurely following a change in Thai guidelines recommending antiretroviral combination therapy for all pregnant women. Data on 405 mothers and 407 live-born children were analyzed. Baseline characteristics were similar between arms. Intent-to-treat transmission rates were 3.8% (95% confidence interval: 1.2-8.6) in NVP-NVP, 1.6% (0.2-5.6) in infant-only NVP, and 1.4% (0.4-5.1) in LPV/r arms. As-treated rates were 2.2% (0.5-6.4), 3.2% (0.9-7.9), and 1.5% (0.2-5.2), respectively. Factors independently associated with transmission were prophylaxis duration less than 8 weeks (adjusted odds ratio 15.5; 3.6-66.1) and viral load at baseline at least 4 log10copies/ml (adjusted odds ratio 10.9; 1.3-91.5). Regimens appeared well tolerated.

CONCLUSION

Transmission rates in all arms were low but noninferiority was not proven. Antiretroviral prophylaxis for at least 8 weeks before delivery is necessary to minimize transmission risk.

Single-dose nevirapine exposure does not affect response to antiretroviral therapy in HIV-infected African children aged below 3 years

OBJECTIVES

To assess the impact of exposure to single-dose nevirapine (sdNVP) on virological response in young Ugandan/Zimbabwean children (<3 years) initiating antiretroviral therapy (ART), and to investigate other predictors of response.

DESIGN

Observational analysis within the ARROW randomized trial.

METHODS

sdNVP exposure was ascertained by the caregiver's self-report when the child initiated non-nucleoside reverse transcriptase inhibitor (NNRTI)-based ART. Viral load was assayed retrospectively over a median 4.1 years of follow-up. Multivariable logistic regression models were used to identify independent predictors of viral load below 80 copies/ml, 48 and 144 weeks after ART initiation (backwards elimination, exit P = 0.1).

RESULTS

Median (IQR) age at ART initiation was 17 (10-23) months in 78 sdNVP-exposed children vs. 21 (14-27) months in 289 non-exposed children (36 vs. 20% <12 months). At week 48, 49 of 73 (67%) sdNVP-exposed and 154 of 272 (57%) non-exposed children had viral load below 80 copies/ml [adjusted odds ratio (aOR) 2.34 (1.26-4.34), P = 0.007]; 79 and 77% had viral load below 400 copies/ml. Suppression was significantly lower in males (P = 0.009), those with higher pre-ART viral load (P = 0.001), taking syrups (P = 0.05) and with lower self-reported adherence (P = 0.04). At week 144, 55 of 73 (75%) exposed and 188 of 272 (69%) non-exposed children had less than 80 copies/ml [aOR 1.75 (0.93-3.29), P = 0.08]. There was no difference between children with and without previous sdNVP exposure in intermediate/high-level resistance to NRTIs (P > 0.3) or NNRTIs (P > 0.1) (n = 88) at week 144.

CONCLUSION

Given the limited global availability of lopinavir/ritonavir, its significant formulation challenges in young children, and the significant paediatric treatment gap, tablet fixed-dose-combination NVP-based ART remains a good alternative to syrup lopinavir-based ART for children, particularly those over 1 year and even if exposed to sdNVP.

Comparison of HBV-active HAART regimens in an HIV-HBV multinational cohort: outcomes through 144 weeks

OBJECTIVES

To explore factors associated with short and long-term hepatitis B virus (HBV) DNA suppression in a multinational cohort of HIV-HBV co-infected patients receiving HBV-active antiretrovirals.

METHODS

One hundred and fifteen HIV-HBV co-infected patients participating in one of the two global randomized clinical trials conducted by the Adult AIDS Clinical Trials Group of different antiretroviral regimens received either HBV monotherapy with either lamivudine or emtricitabine (N = 56), or HBV dual therapy with tenofovir disoproxil fumarate (TDF) + lamivudine or emtricitabine (N = 59). Associations of pretreatment characteristics with the primary (HBV DNA <200 IU/ml at 24 weeks) and longitudinal outcomes through 144 weeks were explored using logistic regression. HBV drug-resistance mutations were determined by pol sequencing in those with viral rebound.

RESULTS

The proportion with HBV DNA below 200 IU/ml was 60% (95% confidence interval 50-69%) at 24 weeks and 79% (95% confidence interval 69-88%) at 144 weeks. Pretreatment factors associated with the primary outcome were HBV DNA, CD4 T-cell count, and aspartate aminotransferase, but only pretreatment HBV DNA remained associated with long-term suppression (P < 0.0001). HBV therapy group was not significantly associated with the primary outcome at 24 weeks; however, longitudinally, a greater proportion in the dual-therapy group achieved HBV DNA below 200 IU/ml (P = 0.007). A higher proportion of hepatitis B e antigen-negative patients (n = 57) achieved HBV DNA below 200 IU/ml at any point, regardless of the therapy group. All 12 patients with emergence of lamivudine-resistant mutants were in the monotherapy group.

CONCLUSIONS

TDF-based dual HBV-active antiretroviral therapy is preferred to treat HIV-HBV co-infected patients. In resource-limited settings in which TDF may not be universally available, lamivudine or emtricitabine HBV monotherapy is a reasonable option in patients with low HBV replication.

Effect of cotrimoxazole prophylaxis on malaria occurrence in HIV-infected patients on antiretroviral therapy in sub-Saharan Africa

OBJECTIVE

To systematically review the evidence on the effect of cotrimoxazole (CTX) on malaria in HIV-positive individuals on antiretroviral therapy (ART).

METHODS

Web of Science, PubMed and MEDLINE, EMBASE, Global Health and Cochrane Library databases were searched using terms for malaria, HIV and CTX. Studies meeting the inclusion criteria were reviewed and assessed for bias and confounding.

RESULTS

Six studies (in Uganda, Kenya, Malawi, Zambia and Zimbabwe) had relevant data on the effect of CTX on malaria in patients on ART: four were observational cohort studies (OCS) and two were randomised controlled trials (RCTs); two were in children and one in women only. Samples sizes ranged from 265 to 2200 patients. Four studies compared patients on ART and CTX with patients on ART alone; 2 (RCTs) found a significant increase in smear-positive malaria on ART alone: (IRR 32.5 CI = 8.6-275.0 and HR 2.2 CI = 1.5-3.3) and 2 (OCS) reported fewer parasitaemia episodes on CTX and ART (OR 0.85 CI = 0.65-1.11 and 3.6% vs. 2.4% of samples P = 0.14). One OCS found a 76% (95% CI = 63-84%) vs. 83% (95% CI = 74-89%) reduction in malaria incidence in children on CTX and ART vs. on CTX only, when both were compared with HIV-negative children. The other reported a 64% reduction in malaria incidence after adding ART to CTX (RR = 0.36, 95% CI = 0.18-0.74). The 2 RCTs were unblinded. Only one study reported adherence to CTX and ART, and only two controlled for baseline CD4 count.

CONCLUSION

Few studies have investigated the effect of CTX on malaria in patients on ART. Their findings suggest that CTX is protective against malaria even among patients on ART.

Point-of-care CD4 testing to inform selection of antiretroviral medications in south african antenatal clinics: a cost-effectiveness analysis

BACKGROUND

Many prevention of mother-to-child HIV transmission (PMTCT) programs currently prioritize antiretroviral therapy (ART) for women with advanced HIV. Point-of-care (POC) CD4 assays may expedite the selection of three-drug ART instead of zidovudine, but are costlier than traditional laboratory assays.

METHODS

We used validated models of HIV infection to simulate pregnant, HIV-infected women (mean age 26 years, gestational age 26 weeks) in a general antenatal clinic in South Africa, and their infants. We examined two strategies for CD4 testing after HIV diagnosis: laboratory (test rate: 96%, result-return rate: 87%, cost: $14) and POC (test rate: 99%, result-return rate: 95%, cost: $26). We modeled South African PMTCT guidelines during the study period (WHO "Option A"): antenatal zidovudine (CD4 ≤350/μL) or ART (CD4>350/μL). Outcomes included MTCT risk at weaning (age 6 months), maternal and pediatric life expectancy (LE), maternal and pediatric lifetime healthcare costs (2013 USD), and cost-effectiveness ($/life-year saved).

RESULTS

In the base case, laboratory led to projected MTCT risks of 5.7%, undiscounted pediatric LE of 53.2 years, and undiscounted PMTCT plus pediatric lifetime costs of $1,070/infant. POC led to lower modeled MTCT risk (5.3%), greater pediatric LE (53.4 years) and lower PMTCT plus pediatric lifetime costs ($1,040/infant). Maternal outcomes following laboratory were similar to POC (LE: 21.2 years; lifetime costs: $23,860/person). Compared to laboratory, POC improved clinical outcomes and reduced healthcare costs.

CONCLUSIONS

In antenatal clinics implementing Option A, the higher initial cost of a one-time POC CD4 assay will be offset by cost-savings from prevention of pediatric HIV infection.

Prevention of perinatal transmission of human immunodeficiency virus

The reproductive health needs of all women of childbearing age should routinely address effective and appropriate contraception, safer sex practices, and elimination of alcohol, illicit drugs and tobacco should pregnancy occur. Combined antepartum, intrapartum, and infant antiretroviral (ARV) prophylaxis are recommended because ARV drugs reduce perinatal transmission by several mechanisms, including lowering maternal viral load and providing infant pre- and post-exposure prophylaxis. Scheduled cesarean delivery at 38 weeks with IV AZT decreases the risk of perinatal transmission if the HIV RNA is greater than 1000 copies/mL or if HIV levels are unknown near the time of delivery. Oral AZT should generally be given for at least 6 weeks to all infants perinatally exposed to HIV to reduce perinatal transmission of HIV.

Frequency of Antiretroviral Resistance Mutations among Infants Exposed to Single-Dose Nevirapine and Short Course Maternal Antiretroviral Regimens: ACTG A5207

Background

Intrapartum single-dose nevirapine (sdNVP) reduces HIV-1 perinatal transmission but selects NVP resistance among mothers and infants. We evaluated the frequency of antiretroviral resistance among infants with intrauterine HIV-1 infection exposed to sdNVP and maternal antenatal or breastfeeding antiretroviral therapy.

Methods

This analysis included 429 infants from sub-Saharan Africa, India and Haiti whose 422 mothers received sdNVP plus maternal study treatment. At entry mothers had CD4>250/μL and were ART-naïve except for antenatal ZDV per local standard of care. Maternal study treatment started intrapartum and included ZDV/3TC, TDF/FTC or LPV/r for 7 or 21 days in a randomized factorial design. Infants received sdNVP study treatment and ZDV if local standard of care. Infant HIV RNA or DNA PCR and samples for genotype were obtained at birth and weeks 2, 4 and 12; infants who ever breast-fed were also tested at weeks 16, 24, 48 and 96. Samples from HIV-1-infected infants were tested for drug resistance by population genotype (ViroSeq). NVP or NRTI resistance mutations were assessed using the IAS-USA mutation list.

Results

Perinatal HIV-1 transmission occurred in 17 (4.0%) infants including 12 intrauterine infections. Resistance mutations were detected among 5 (42%) intrauterine-infected infants; of these, 3 had mutations conferring resistance to NVP alone, 1 had resistance to NRTI alone, and 1 had dual-class resistance mutations. Among the 2 infants with NRTI mutations, one (K70R) was likely maternally transmitted and one (K65R) occurred in the context of breastfeeding exposure to maternal antiretroviral therapy.

Conclusions

Infants with intrauterine HIV infection are at risk of acquiring resistance mutations from exposure to maternal antiretroviral medications intrapartum and/or during breastfeeding. New approaches are needed to lower the risk of antiretroviral resistance in these infants.

The relation between efavirenz versus nevirapine and virologic failure in Johannesburg, South Africa

Introduction

Previous research has raised concerns that patients given nevirapine (NVP)-based regimens experience more virologic failure than patients given efavirenz (EFV)-based regimens. We investigated this hypothesis in a cohort of HIV-positive patients at a large HIV treatment clinic in South Africa.

Methods

All antiretroviral therapy (ART)-naïve non-pregnant patients, ≥18 years old, without tuberculosis, who initiated treatment with either NVP or EFV from April 2004 to August 2011 at the Themba Lethu Clinic in Johannesburg, South Africa, were included. Log-binomial regression and modified Poisson regression were used to estimate risk ratios (RR) with 95% confidence intervals (CI) for predictors of virologic failure, virologic suppression, and loss to follow-up (LTF), whereas a Cox proportional hazards model was used to estimate the risk of death, all within one year.

Results

Of 12,840 included patients, 62.0% were female and the median baseline CD4 count was 98 cells/mm³ (36–169). Of these patients, 93.2% initiated an EFV-based regimen. After adjusting for baseline characteristics, no difference in death (adjusted Hazards Ratio (aHR): 0.92; 95% CI: 0.68–1.25), LTF (adjusted Risk Ratio (aRR): 1.00; 95% CI: 0.79–1.25), nor suppression (aRR: 0.98; 95% CI: 0.95–1.00) at one year was found between regimens. Among patients with ≥1 viral load ≥4 months after ART initiation, 4% (n=350) experienced virologic failure within 12 months of initiation. Patients initiating NVP-based regimens were 60% more likely to fail than patients initiating EFV-based regimens (aRR: 1.58; 95% CI: 1.13–2.22).

Conclusions

In this cohort, patients initiating NVP-based regimens experienced more virologic failure than patients initiating EFV-based regimens. Future guidelines should consider the implications of different efficacy profiles when making recommendations for which drugs to prioritize.

Predictors of virologic and clinical response to nevirapine versus lopinavir/ritonavir-based antiretroviral therapy in young children with and without prior nevirapine exposure for the prevention of mother-to-child HIV transmission

BACKGROUND

In a randomized trial comparing nevirapine (NVP)-based versus lopinavir/ritonavir (LPV/r)-based antiretroviral therapy (ART) in HIV-infected children [primary endpoint discontinuation of study treatment for any reason or virologic failure by week 24] aged 2 months to 3 years, we assessed whether clinical, virologic, immunologic and safety outcomes varied by prior single-dose NVP exposure (PrNVP) for prevention of mother-to-child HIV transmission and other covariates.

METHODS

Efficacy was assessed by time to ART discontinuation or virologic failure, virologic failure/death and death; safety by time to ART discontinuation because of a protocol-defined toxicity and first ≥ grade 3 adverse event; immunology and growth by changes in CD4%, weight/height World Health Organization z-scores from entry to week 48. Cox proportional hazards and linear regression models were used to test whether treatment differences depended on PrNVP exposure and other covariates.

RESULTS

Over a median follow up of 48 (PrNVP) and 72 (no PrNVP) weeks, there was no evidence of differential treatment effects by PrNVP exposure or any other covariates. LPV/r-based ART was superior to NVP-based ART for efficacy and safety outcomes; however, those on NVP had larger improvements in CD4%, weight and height z-scores. Lower pretreatment CD4% and higher HIV-1 RNA levels were associated with reduced efficacy, lower pretreatment CD4% with shorter time to ART discontinuation because of a protocol-defined toxicity, and no PrNVP with shorter time to first grade ≥ 3 adverse event.

CONCLUSIONS

Differences between LPV/r and NVP ART in efficacy, safety, immunologic and growth outcomes did not depend on PrNVP exposure, prior breast-feeding, sex, HIV-1 subtype, age, pretreatment CD4%, HIV-1 RNA or World Health Organization disease stage. This finding should be considered when selecting an ART regimen for young children.

Increase in transmitted resistance to non-nucleoside reverse transcriptase inhibitors among newly diagnosed HIV-1 infections in Europe

Background

One out of ten newly diagnosed patients in Europe was infected with a virus carrying a drug resistant mutation. We analysed the patterns over time for transmitted drug resistance mutations (TDRM) using data from the European Spread program.

Methods

Clinical, epidemiological and virological data from 4317 patients newly diagnosed with HIV-1 infection between 2002 and 2007 were analysed. Patients were enrolled using a pre-defined sampling strategy.

Results

The overall prevalence of TDRM in this period was 8.9% (95% CI: 8.1-9.8). Interestingly, significant changes over time in TDRM caused by the different drug classes were found. Whereas nucleoside resistance mutations remained constant at 5%, a significant decline in protease inhibitors resistance mutations was observed, from 3.9% in 2002 to 1.6% in 2007 (p = 0.001). In contrast, resistance to non-nucleoside reverse transcriptase inhibitors (NNRTIs) doubled from 2.0% in 2002 to 4.1% in 2007 (p = 0.004) with 58% of viral strains carrying a K103N mutation. Phylogenetic analysis showed that these temporal changes could not be explained by large clusters of TDRM.

Conclusion

During the years 2002 to 2007 transmitted resistance to NNRTI has doubled to 4% in Europe. The frequent use of NNRTI in first-line regimens and the clinical impact of NNRTI mutations warrants continued monitoring.

Cardiovascular disease risk factors in HIV-infected women after initiation of lopinavir/ritonavir- and nevirapine-based antiretroviral therapy in Sub-Saharan Africa: A5208 (OCTANE)

BACKGROUND

Limited comparative, prospective data exist regarding cardiovascular risk factors in HIV-infected women starting antiretroviral therapy in Africa.

METHODS

In 7 African countries, 741 women with CD4 <200 cells/mm were randomized to tenofovir/emtricitabine (TDF/FTC) plus either nevirapine (NVP, n = 370) or lopinavir/ritonavir (LPV/r, n = 371). Lipids and blood pressure (BP) were evaluated at entry, 48, 96, and 144 weeks. Multivariable linear and logistic regression models were used to evaluate mean risk factor changes and clinically relevant risk factor changes.

RESULTS

At entry, both NVP and LPV/r groups were similar regarding age [mean = 33.5 (SD = 7.1) years], CD4 [129 (67) cells/mm], and HIV-1 RNA [5.1 (0.6) log10 copies/mL]. Nearly, all women had normal lipids and BP except for high-density lipoprotein (HDL)-cholesterol. Over 144 weeks, the LPV/r compared with NVP group had significantly greater mean lipid increases (eg, non-HDL: +29 vs. +13 mg/dL) and smaller HDL increases (+12 vs. +21 mg/dL). In contrast, the NVP compared with LPV/r group had greater mean increases in BP (eg, diastolic BP: +5 vs. -0.5 mm Hg). Significantly, more women assigned LPV/r had week 144 "abnormal" lipid levels (eg, HDL 29.7% vs. 14.8% and triglycerides 28.6% vs. 8.2%), and significantly, more women assigned NVP had "abnormal" BP (eg, diastolic BP 22.7% vs. 6.5%). Most differences remained significant when adjusted for baseline risk factor, age, CD4, and HIV-1 RNA.

CONCLUSIONS

In HIV-infected women initiating antiretroviral therapy in Africa, LPV/r + TDF/FTC was associated with less favorable changes in lipids, and use of NVP + TDF/FTC was associated with less favorable changes in BP.

Virologic and immunologic outcomes of HIV-infected Ugandan children randomized to lopinavir/ritonavir or nonnucleoside reverse transcriptase inhibitor therapy

BACKGROUND

In the Prevention of Malaria and HIV disease in Tororo pediatrics trial, HIV-infected Ugandan children randomized to receive lopinavir/ritonavir (LPV/r)-based antiretroviral therapy (ART) experienced a lower incidence of malaria compared with children receiving nonnucleoside reverse transcriptase inhibitor (NNRTI)-based ART. Here we present the results of the noninferiority analysis of virologic efficacy and comparison of immunologic outcomes.

METHODS

ART-naive or -experienced (HIV RNA <400 copies/mL) children aged 2 months to 6 years received either LPV/r or NNRTI-based ART. The proportion of children with virologic suppression (HIV RNA <400 copies/mL) at 48 weeks was compared using a prespecified noninferiority margin of -11% in per-protocol analysis. Time to virologic failure by 96 weeks, change in CD4 counts and percentages, and incidence of adverse event rates were also compared.

RESULTS

Of 185 children enrolled, 91 initiated LPV/r and 92 initiated NNRTI-based ART. At baseline, the median age was 3.1 years (range, 0.4-5.9), and 131 (71%) children were ART-naive. The proportion of children with virologic suppression at 48 weeks was 80% (67/84) in the LPV/r arm vs. 76% (59/78) in the NNRTI arm, a difference of 4% (95% confidence interval: -9% to +17%). Time to virologic failure, CD4 changes, and the incidence of Division of AIDS grade III/IV adverse events were similar between arms.

CONCLUSIONS

LPV/r-based ART was not associated with worse virologic efficacy, immunologic efficacy, or adverse event rates compared with NNRTI-based ART. Considering these results and the reduction in malaria incidence associated with LPV/r previously reported for this trial, wider use of LPV/r to treat HIV-infected African children in similar malaria-endemic settings could be considered.

Combination antiretroviral treatment for women previously treated only in pregnancy: week 24 results of AIDS clinical trials group protocol a5227

BACKGROUND

Women with HIV and prior exposure to combination antiretroviral therapy (cART) solely for prevention of mother-to-child transmission (pMTCT) need to know whether they can later be treated successfully with a commonly used regimen of efavirenz (EFV) and coformulated emtricitabine (FTC) and tenofovir disoproxil fumarate (TDF).

METHODS

Nonpregnant women with plasma HIV-1 RNA of ≥500 copies per milliliter, previously cART exposed for pMTCT only, were eligible if they were off ART for ≥24 weeks before entry, were without evidence of drug resistance on standard genotyping, and were ready to start EFV plus FTC/TDF. The primary endpoint was virologic response (defined as plasma HIV RNA <400 copies/mL) at 24 weeks.

RESULTS

Fifty-four women were enrolled between October 2007 and December 2009; 52 of 54 completed 24 weeks of follow-up. Median baseline CD4 T-cell count was 265/mm and baseline plasma HIV-1 RNA was 4.6 log10 copies per milliliter. Median prior cART duration was 14 weeks, and median time elapsed from the last pMTCT dose to entry was 22 months. Virologic response at 24 weeks was observed in 42 of 52 women or 81% (exact 95% confidence interval: 68% to 90%). There were no differences in response by country, by number, or class of prior pMTCT exposures. Although confirmed virologic failure occurred in 8 women, no virologic failures were observed in women reporting perfect early adherence.

CONCLUSIONS

In this first prospective clinical trial studying combination antiretroviral retreatment in women with a history of pregnancy-limited cART, the observed virologic response to TDF/FTC and EFV at 24 weeks was 81%. Virologic failures occurred and correlated with self-reported nonadherence.

Predictors of suboptimal CD4 response among women achieving virologic suppression in a randomized antiretroviral treatment trial, Africa

Background

A subset of HIV-1 infected patients starting highly active antiretroviral treatment (HAART) experience suboptimal CD4 response (SCR) despite virologic suppression. We studied the rate of and risk factors for SCR among women starting HAART in the ACTG A5208 study conducted in 7 African countries. 741 HAART-naive women with screening CD4 count <200 cells/μL were randomized to start HAART with Tenofovir/Emtricitabine plus either Nevirapine or Lopinavir/Ritonavir.

Methods

This analysis includes the 625 women who remained on-study through 48 weeks without experiencing protocol-defined virologic failure. We defined SCR as < 100 CD4 cells/μL increase from baseline and absolute CD4 cell count < 350 cells/μL, both at 48 weeks after HAART initiation.

Results

The baseline characteristics for the 625 women prior to HAART initiation were: median age 33 years, screening CD4 count 134 cells/μL, and HIV-1 RNA 5.1 log₁₀ copies/mL; 184 (29%) were WHO Stage 3 or 4.

Seventy one (11%) of these 625 women experienced SCR. Baseline factors independently associated with increased odds of SCR included older age, lower HIV-1 RNA, positive Hepatitis B surface antigen, and site location. At 96 weeks, only 6% of the SCR group had CD4 ≥ 350 cells/μL compared with 67% in the non SCR group.

Conclusion

After starting HAART, 11% of women with virologic suppression through 48 weeks experienced SCR. These patients were also less likely to achieve CD4 ≥ 350 cells/μL by 96 weeks. The underlying causes and long term clinical implications of SCR deserve further investigation.

Trial registration

Clinicaltrials.gov Identifier: NCT00089505

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

BACKGROUND

Virologic failure (VF) on a first-line ritonavir-boosted protease inhibitor (PI/r) regimen is associated with low rates of resistance, but optimal management after failure is unknown.

METHODS

The analysis included participants in randomized trials who experienced VF on a first-line regimen of PI/r plus 2 nucleoside reverse transcriptase inhibitors (NRTIs) and had at least 24 weeks of follow-up after VF. Antiretroviral management and virologic suppression (human immunodeficiency virus type 1 [HIV-1] RNA <400 copies/mL) after VF were assessed.

RESULTS

Of 209 participants, only 1 participant had major PI-associated treatment-emergent mutations at first-line VF. The most common treatment approach after VF (66%) was to continue the same regimen. The virologic suppression rate 24 weeks after VF was 64% for these participants, compared with 72% for those who changed regimens (P = .19). Participants remaining on the same regimen had lower NRTI resistance rates (11% vs 30%; P = .003) and higher CD4(+) cell counts (median, 275 vs 213 cells/µL; P = .005) at VF than those who changed. Among participants remaining on their first-line regimen, factors at or before VF significantly associated with subsequent virologic suppression were achieving HIV-1 RNA <400 copies/mL before VF (odds ratio [OR], 3.39 [95% confidence interval {CI}, 1.32-8.73]) and lower HIV-1 RNA at VF (OR for <10 000 vs ≥10 000 copies/mL, 3.35 [95% CI, 1.40-8.01]). Better adherence after VF was also associated with subsequent suppression (OR for <100% vs 100%, 0.38 [95% CI, .15-.97]). For participants who changed regimens, achieving HIV-1 RNA <400 copies/mL before VF also predicted subsequent suppression.

CONCLUSIONS

For participants failing first-line PI/r with no or limited drug resistance, remaining on the same regimen is a reasonable approach. Improving adherence is important to subsequent treatment success.

Clinical focus: infections in pregnancy

Pregnant women are particularly susceptible to a number of infectious diseases, such as influenza, hepatitis E, malaria, and tuberculosis. The management of many other infections-including urinary tract infections, human immunodeficiency virus, and sexually transmitted diseases-is also made more complex by pregnancy; even if some infections do not pose a great risk to the expectant mother, they can impact fetal and neonatal development, thus posing a treatment challenge to physicians. By focusing on the most important diseases that physicians may encounter in pregnant patients, this review outlines the challenges associated with managing important infectious diseases in the pregnant population and references the most recent evidence and international treatment guidelines.

Addressing standards of care in resource-limited settings

: The choice between "best-known" standards of care (SOC) or "best available" standards as the control arm in a clinical trial is a fundamental dilemma in clinical research in resource-limited settings (RLS). When the health system is delivering less than an optimal level of care, using highest standard of care in a clinical trial may produce results that cannot be implemented or sustained locally. On the other hand, using interventions that are more feasible in the local setting may involve suboptimal care, and clinical outcomes may be affected. The need for improved standards in health systems in RLS, and the difficulty in securing them, has led many researchers advocate for policy changes at the national or international level to improve clinical care more systemically. SOC decisions in a clinical trial affect the level of benefit provided to study participants and the policy implications of the trial findings. SOC choices should provide high-quality care to help advance the health care system in host countries participating in the trial, but balancing the scientific and ethical objectives of SOC choices is difficult, and there is no single formula for selecting the appropriate SOC. Despite the challenges, well-designed and conducted clinical trials can and should make significant contributions to health systems in RLS.

Low-frequency nevirapine (NVP)-resistant HIV-1 variants are not associated with failure of antiretroviral therapy in women without prior exposure to single-dose NVP

BACKGROUND

Low-frequency nevirapine (NVP)-resistant variants have been associated with virologic failure (VF) of initial NVP-based combination antiretroviral therapy (cART) in women with prior exposure to single-dose NVP (sdNVP). We investigated whether a similar association exists in women without prior sdNVP exposure.

METHODS

Pre-cART plasma was analyzed by allele-specific polymerase chain reaction to quantify NVP-resistant mutants in human immunodeficiency virus-infected African women without prior sdNVP who were starting first-line NVP-based cART in the OCTANE/A5208 trial 2. Associations between NVP-resistant mutants and VF or death were determined and compared with published results from women participating in the OCTANE/A5208 trial 1 who had taken sdNVP and initiated NVP-based cART.

RESULTS

Pre-cART NVP-resistant variants were detected in 18% (39/219) of women without prior sdNVP exposure, compared to 45% (51/114) with prior sdNVP exposure (P < .001). Among women without prior sdNVP exposure, 8 of 39 (21%) with NVP-resistant variants experienced VF or death vs 31 of 180 (17%) without such variants (P = .65); this compares with 21 of 51 (41%) vs 9 of 63 (14%) among women with prior exposure (P = .001).

CONCLUSIONS

The risk of VF on NVP-based cART from NVP-resistant variants differs between sdNVP-exposed and -unexposed women. This difference may be driven by drug-resistance mutations emerging after sdNVP exposure that are linked on the same viral genome.

CLINICAL TRIALS REGISTRATION

NCT00089505.

[Consensus Statement by GeSIDA/National AIDS Plan Secretariat on antiretroviral treatment in adults infected by the human immunodeficiency virus (Updated January 2013)]

OBJECTIVE

This consensus document is an update of combined antiretroviral therapy (cART) guidelines for HIV-1 infected adult patients.

METHODS

To formulate these recommendations a panel composed of members of the GeSIDA/National AIDS Plan Secretariat (Grupo de Estudio de Sida and the Secretaría del Plan Nacional sobre el Sida) reviewed the efficacy and safety advances in clinical trials, cohort and pharmacokinetic studies published in medical journals (PubMed and Embase) or presented in medical scientific meetings. The strength of the recommendations and the evidence which support them are based on a modification of the criteria of Infectious Diseases Society of America.

RESULTS

cART is recommended in patients with symptoms of HIV infection, in pregnant women, in serodiscordant couples with high risk of transmission, in hepatitisB co-infection requiring treatment, and in HIV nephropathy. cART is recommended in asymptomatic patients if CD4 is <500cells/μl. If CD4 are >500cells/μl cART should be considered in the case of chronic hepatitisC, cirrhosis, high cardiovascular risk, plasma viral load >100.000 copies/ml, proportion of CD4 cells <14%, neurocognitive deficits, and in people aged >55years. The objective of cART is to achieve an undetectable viral load. The first cART should include 2 reverse transcriptase inhibitors (RTI) nucleoside analogs and a third drug (a non-analog RTI, a ritonavir boosted protease inhibitor, or an integrase inhibitor). The panel has consensually selected some drug combinations, for the first cART and specific criteria for cART in acute HIV infection, in tuberculosis and other HIV related opportunistic infections, for the women and in pregnancy, in hepatitisB or C co-infection, in HIV-2 infection, and in post-exposure prophylaxis.

CONCLUSIONS

These new guidelines update previous recommendations related to first cART (when to begin and what drugs should be used), how to monitor, and what to do in case of viral failure or adverse drug reactions. cART specific criteria in comorbid patients and special situations are similarly updated.

Nevirapine-based regimens in HIV-infected antiretroviral-naive patients: systematic review and meta-analysis of randomized controlled trials

Background

Nevirapine belongs to the group of non-nucleoside reverse transcriptase inhibitors (NNRTIs) and is commonly administered in first-line treatment of HIV infection.

Objective

Systematic review and meta-analysis was undertaken to compare effectiveness of nevirapine-based regimens with other antiretroviral schedules used as an initial treatment of HIV-infected antiretroviral-naive subjects.

Methods

Electronic databases (PubMed, EMBASE, the Cochrane Library, Trip Database) were searched up to 28 December 2012 for randomized controlled trials (RCTs) published as a full text and regarding nevirapine-based regimens used as a initial treatment for HIV infection. Meta-analysis was performed with RevMan^® V 5.2 software.

Results

Twelve RCTs were included in the systematic review and all of them were suitable for meta-analysis. Results of the meta-analysis have shown that nevirapine, efavirenz, and ritonavir-boosted protease inhibitor, added to the background regimens, were equally effective in terms of reaching undetectable plasma HIV RNA level as well as risk of disease progression or death. Compared with ritonavir-boosted protease inhibitor-based regimens, nevirapine-based regimens statistically significantly increased the risk of discontinuation of assigned treatment (RR=3.10; 95% CI: 1.14-8.41; p<0.05).

Conclusions

Despite limited RCTs data available for particular comparisons, our results suggest that nevirapine-based regimens may be considered for first-line treatment of HIV-infected adults, due to their comparable efficacy to the other currently recommended initial antiretroviral therapies.

Time to viral load suppression in antiretroviral-naive and -experienced HIV-infected pregnant women on highly active antiretroviral therapy: implications for pregnant women presenting late in gestation

OBJECTIVE

To compare time to achieve viral load <400 copies/ml and <1000 copies/ml in HIV-infected antiretroviral (ARV) -naive versus ARV-experienced pregnant women on highly active antiretroviral therapy (HAART).

DESIGN

Retrospective cohort study.

SETTING

Three university medical centers, USA.

POPULATION

HIV-infected pregnant women initiated or restarted on HAART during pregnancy.

METHODS

We calculated time to viral load <400 copies/ml and <1000 copies/ml in HIV-infected pregnant women on HAART who reported at least 50% adherence, stratifying based on previous ARV exposure history.

MAIN OUTCOME MEASURES

Time to HIV viral load <400 copies/ml and <1000 copies/ml.

RESULTS

We evaluated 138 HIV-infected pregnant women, comprising 76 ARV-naive and 62 ARV-experienced. Ninety-three percent of ARV-naive women achieved a viral load < 400 copies/ml during pregnancy compared with 92% of ARV-experienced women (P = 0.82). The median number of days to achieve a viral load < 400 copies/ml in the ARV-naive cohort was 25.0 (range 3.5-133; interquartile range 16-34) days compared with 27.0 (range 8-162.5; interquartile range 18.5-54.3) days in the ARV-experienced cohort (P = 0.02). In a multiple predictor analysis, women with higher adherence (adjusted relative hazard [aRH] per 10% increase in adherence 1.29, 95% confidence interval [CI] 1.08-1.54, P = 0.01) and receiving a non-nucleotide reverse transcriptase inhibitor (NNRTI) -based regimen (aRH 2.48, 95% CI 1.33-4.63, P = 0.01) were more likely to achieve viral load <400 copies/ml earlier. Increased baseline HIV log10 viral load was associated with a later time of achieving viral load <400 copies/ml (aRH 0.60, 95% CI 0.39-0.92, P = 0.02). In a corresponding model of time to achieve viral load <1000 copies/ml, adherence (aRH per 10% increase in adherence 1.79, 95% CI 1.34-2.39, P < 0.001), receipt of NNRTI (aRH 2.95, 95% CI 1.23-7.06, P = 0.02), and CD4 cell count (aRH per 50 count increase in CD4 1.12, 95% CI 1.03-1.22, P = 0.01) were associated with an earlier time to achieve viral load below this threshold. Increasing baseline HIV log10 viral load was associated with a longer time of achieving viral load <1000 copies/ml (aRH 0.54, 95% CI 0.34-0.86, P = 0.01). In multiple predictor models, previous ARV exposure was not significantly associated with time to achieve viral load below thresholds of <400 copies/ml and <1000 copies/ml.

CONCLUSIONS

Pregnant women with ≥50% adherence, whether ARV-naive or ARV-experienced, on average achieve a viral load <400 copies/ml within a median of 26 days and a viral load of <1000 copies/ml within a median of 14 days of HAART initiation. Increased adherence, receipt of NNRTI-based regimen and lower baseline HIV log10 viral load were all statistically significant predictors of earlier time to achieve viral load <400 copies/ml and <1000 copies/ml. Increased CD4 count was statistically significant as a predictor of earlier time to achieve viral load <1000 copies/ml.

Impact of antiretroviral drugs in pregnant women and their children in Africa: HIV resistance and treatment outcomes

The global community has committed itself to eliminating new pediatric HIV infections by 2015 and improving maternal, newborn, and child health and survival in the context of HIV. Such objectives require regimens to prevent mother-to-child transmission (pMTCT) which, while being highly efficacious, protect the efficacy of future first-line antiretroviral therapy (ART). Major obstacles to eliminating vertical transmissions globally include low rates of adherence to ART and non-completion of the 'pMTCT cascade' due to programmatic and structural challenges faced by healthcare systems in low-income countries. Providing all pregnant women with lifelong ART regardless of CD4 count/disease stage (Option B+) could be the most effective option to prevent both HIV transmission and resistance, assuming adherence is successfully maintained. This strategy is more likely to achieve sustained undetectable HIV viremia, does not involve ART interruptions, is simpler to implement, and is cost-effective. Where Option B+ is not available, options A (short course zidovudine with single-dose nevirapine and an ARV "tail") and B (combination ART during pregnancy and breastfeeding, with ART cessation after weaning in women not qualifying for ART for their own health) are also efficacious, highly cost-effective and associated with infrequent resistance selection if taken properly.

Antiretroviral treatment sequencing strategies to overcome HIV type 1 drug resistance in adolescents and adults in low-middle-income countries

Antiretroviral treatment (ART) is expanding to human immunodeficiency virus type 1 (HIV-1)-infected persons in low-middle income countries, thanks to a public health approach. With 3 available drug classes, 2 ART sequencing lines are programmatically foreseen. The emergence and transmission of viral drug resistance represents a challenge to the efficacy of ART. Knowledge of HIV-1 drug resistance selection associated with specific drugs and regimens and the consequent activity of residual drug options are essential in programming ART sequencing options aimed at preserving ART efficacy for as long as possible. This article determines optimal ART sequencing options for overcoming HIV-1 drug resistance in resource-limited settings, using currently available drugs and treatment monitoring opportunities. From the perspective of drug resistance and on the basis of limited virologic monitoring data, optimal sequencing seems to involve use of a tenofovir-containing nonnucleoside reverse-transcriptase inhibitor-based first-line regimen, followed by a zidovudine-containing, protease inhibitor (PI)-based second-line regimen. Other options and their consequences are explored by considering within-class and between-class sequencing opportunities, including boosted PI monotherapies and future options with integrase inhibitors. Nucleoside reverse-transcriptase inhibitor resistance pathways in HIV-1 subtype C suggest an additional reason for accelerating stavudine phase out. Viral load monitoring avoids the accumulation of resistance mutations that significantly reduce the activity of next-line options. Rational use of resources, including broader access to viral load monitoring, will help ensure 3 lines of fully active treatment options, thereby increasing the duration of ART success.

Effect of 7 days of phenytoin on the pharmacokinetics of and the development of resistance to single-dose nevirapine for perinatal HIV prevention: a randomized pilot trial

OBJECTIVES

To confirm whether 7 days of phenytoin, an enzyme inducer, would decrease the elimination half-life of single-dose nevirapine and to investigate its effect on the development of nevirapine resistance in pregnant, HIV-infected women.

METHODS

In a pharmacokinetic pilot trial (NCT01187719), HIV-infected, antiretroviral (ARV)-naive pregnant women ≥18 years old from Zambia and Tanzania and with CD4 cell counts >350 cells/mm(3) were randomized 1 : 1 to a control (zidovudine pre-delivery, single-dose nevirapine/zidovudine/lamivudine at delivery and zidovudine/lamivudine for 7 days post-delivery) or an intervention (control plus 184 mg of phenytoin once daily for 7 days post-delivery) group. Primary endpoints were the pharmacokinetics of and resistance to nevirapine.

RESULTS

Thirty-five and 37 women were allocated to the control and intervention groups, with median (IQR) ages of 27 (23-31) and 27 (23-33) years, respectively. Twenty-three and 23 women had detectable nevirapine levels at delivery and subsequent samples in the control and the intervention groups, respectively. Geometric mean (GM) (95% CI) plasma levels of nevirapine at delivery were 1.02 (0.58-1.78) mg/L and 1.14 (0.70-1.86) mg/L in the control and intervention groups, respectively (P = 0.76). One week after delivery, 0/23 (0%) and 15/22 (68%) control and intervention mothers, respectively, had undetectable levels of nevirapine (<0.05 mg/L; P<0.001). One week later, the figures were 10/21 (48%) and 18/19 (95%) mothers, respectively (P = 0.002). The GM (95% CI) half-life of nevirapine was 63.2 (52.8-75.7) versus 25.5 (21.6-30.1) h in the control group versus the intervention group (P < 0.001). New nevirapine mutations were found in 0/20 (0%) intervention-group mothers versus 1/21 (5%) control-group mothers. Overall, there was no difference in adverse events reported between the control and intervention arms (P > 0.28).

CONCLUSIONS

Adding 7 days of an enzyme inducer to single-dose nevirapine to prevent mother-to-child transmission of HIV significantly reduced subtherapeutic nevirapine levels by shortening the half-life of nevirapine. As prolonged subtherapeutic nevirapine dosage leads to the emergence of resistance, single-dose nevirapine could be used with phenytoin as an alternative if other ARVs were unavailable.

Microbicides: topical prevention against HIV

Microbicides represent a potential intervention strategy for preventing HIV transmission. Vaginal microbicides would meet the need for a discreet method that women could use to protect themselves against HIV. Although early-generation microbicides failed to demonstrate efficacy, newer candidates are based on more potent antiretroviral (ARV) products. Positive data from the CAPRISA 004 trial of tenofovir gel support use in women and represent a turning point for the field. This article reviews current progress in development of ARV-based microbicides. We discuss the consensus on selection criteria, the potential for drug resistance, rationale for drug combinations, and the use of pharmacokinetic (PK)/pharmacodynamic (PD) assessment in product development. The urgent need for continued progress in development of formulations for sustained delivery is emphasized. Finally, as the boundaries between different prevention technologies become increasingly blurred, consideration is given to the potential synergy of diverse approaches across the prevention landscape.

Prevalence of HIV-1 drug resistance among women screening for HIV prevention trials in KwaZulu-Natal, South Africa (MTN-009)

BACKGROUND

A major concern with using antiretroviral (ARV)-based products for HIV prevention is the potential spread of drug resistance, particularly from individuals who are HIV-infected but unaware of their status. Limited data exist on the prevalence of HIV infection or drug resistance among potential users of ARV-based prevention products.

METHODS

A cross-sectional study of reproductive-aged women who presented to screen for an HIV prevention trial was conducted at 7 clinical sites in Durban, South Africa. CD4+T cell counts, HIV-1 RNA levels and population sequencing of the protease and reverse transcriptase genes were performed for all women with 2 positive HIV rapid tests. Resistance mutations were identified using the Stanford Calibrated Population Resistance Tool.

RESULTS

Of the 1073 evaluable women, 400(37%) were confirmed as HIV-infected. Of those, plasma HIV-1 RNA was detectable in 365/400(91%) and undetectable(<40 copies/ml) in 35/400(9%) women. 156 women(39%) were eligible for antiretroviral therapy (CD4+T cell counts<350 cells/mm(3)) and 50(13%) met criteria for AIDS(CD4<200 cells/mm(3)). Of 352 plasma samples(>200 copies/ml) analyzed for drug resistance, 26(7.4%) had nucleoside reverse transcriptase inhibitor (NRTI), non-nucleoside reverse transcriptase inhibitor (NNRTI) or protease inhibitor (PI) drug resistance mutations. Among those with resistance, 18/26 participants(62%) had single-class NNRTI resistance and 5/26(19%) had dual-class NRTI/NNRTI. Major mutations in reverse transcriptase included K65R(n = 1), L74I(n = 1), K103N(n = 19), V106M(n = 4), Y181C(n = 2), M184V(n = 4), and K219E/R(n = 2). Major PI-resistance mutations were rare: M46L(n = 1) and I85V(n = 1). All participants were infected with subtype C virus, except one infected with subtype A.

CONCLUSIONS

In women from Durban, South Africa screening for an HIV prevention trial, the HIV prevalence was high (37%) and HIV drug resistance prevalence was above 5%. This study highlights the potential challenges faced when implementing an ARV-based prevention product that overlaps with first-line antiretroviral therapy. Effective screening to exclude HIV infection among women interested in uptake of ARV-based HIV prevention will be essential in limiting the spread of ARV resistance.

Cost-effectiveness of pre-exposure prophylaxis (PrEP) in preventing HIV-1 infections in rural Zambia: a modeling study

BACKGROUND

Pre-exposure prophylaxis (PrEP) with tenofovir and emtricitabine effectively prevents new HIV infections. The optimal scenario for implementing PrEP where most infections are averted at the lowest cost is unknown. We determined the impact of different PrEP strategies on averting new infections, prevalence, drug resistance and cost-effectiveness in Macha, a rural setting in Zambia.

METHODS

A deterministic mathematical model of HIV transmission was constructed using data from the Macha epidemic (antenatal prevalence 7.7%). Antiretroviral therapy is started at CD4<350 cells/mm(3). We compared the number of infections averted, cost-effectiveness, and potential emergence of drug resistance of two ends of the prioritization spectrum: prioritizing PrEP to half of the most sexually active individuals (5-15% of the total population), versus randomly putting 40-60% of the total population on PrEP.

RESULTS

Prioritizing PrEP to individuals with the highest sexual activity resulted in more infections averted than a non-prioritized strategy over ten years (31% and 23% reduction in new infections respectively), and also a lower HIV prevalence after ten years (5.7%, 6.4% respectively). The strategy was very cost-effective at $323 per quality adjusted life year gained and appeared to be both less costly and more effective than the non-prioritized strategy. The prevalence of drug resistance due to PrEP was as high as 11.6% when all assumed breakthrough infections resulted in resistance, and as low as 1.3% when 10% of breakthrough infections resulted in resistance in both our prioritized and non-prioritized scenarios.

CONCLUSIONS

Even in settings with low test rates and treatment retention, the use of PrEP can still be a useful strategy in averting infections. Our model has shown that PrEP is a cost-effective strategy for reducing HIV incidence, even when adherence is suboptimal and prioritization is imperfect.

Clinical implications of HIV-1 minority variants

Technologic advances in human immunodeficiency virus type 1 (HIV-1) sequencing have revolutionized the study of antiretroviral drug resistance and are increasingly moving from the laboratory to clinical practice. These techniques are able to detect HIV-1 drug resistance mutations present at low frequencies not detectable by current HIV-1 genotyping assays. For a number of commonly used antiretroviral medications, such as nonnucleoside reverse transcriptase inhibitors, the detection of these drug-resistant minority variants significantly increases the risk of treatment failure. The level of evidence, however, is insufficient to determine the impact of HIV-1 minority variants for several other classes of antiretroviral medications. Clinicians should be aware of the novel technologies that are moving into routine clinical use and the clinical implications of HIV-1 minority variants. Additional studies are needed to determine the optimal platform for clinical application of these new technologies and to provide guidance to clinicians on the type and frequency of clinically important HIV-1 minority variants.