HIV Prevention Among Men Who Have Sex With Men: Tenofovir Alafenamide Combination Preexposure Prophylaxis Versus Placebo

BACKGROUND

While noninferiority of tenofovir alafenamide and emtricitabine (TAF/FTC) as preexposure prophylaxis (PrEP) for the prevention of human immunodeficiency virus (HIV) has been shown, interest remains in its efficacy relative to placebo. We estimate the efficacy of TAF/FTC PrEP versus placebo for the prevention of HIV infection.

METHODS

We used data from the DISCOVER and iPrEx trials to compare TAF/FTC to placebo. DISCOVER was a noninferiority trial conducted from 2016 to 2017. iPrEx was a placebo-controlled trial conducted from 2007 to 2009. Inverse probability weights were used to standardize the iPrEx participants to the distribution of demographics and risk factors in the DISCOVER trial. To check the comparison, we evaluated whether risk of HIV infection in the shared tenofovir disoproxil fumarate and emtricitabine (TDF/FTC) arms was similar.

RESULTS

Notable differences in demographics and risk factors occurred between trials. After standardization, the difference in risk of HIV infection between the TDF/FTC arms was near zero. The risk of HIV with TAF/FTC was 5.8 percentage points lower (95% confidence interval [CI], -2.0% to -9.6%) or 12.5-fold lower (95% CI, .02 to .31) than placebo standardized to the DISCOVER population.

CONCLUSIONS

There was a reduction in HIV infection with TAF/FTC versus placebo across 96 weeks of follow-up.

CLINICAL TRIALS REGISTRATION

NCT02842086 and NCT00458393.

HIV Preexposure Prophylaxis With Emtricitabine and Tenofovir Disoproxil Fumarate Among Cisgender Women

Importance

Emtricitabine and tenofovir disoproxil fumarate (F/TDF) for HIV preexposure prophylaxis (PrEP) is highly effective in cisgender men who have sex with men (MSM) when adherence is high (>4 doses/week). Real-world effectiveness and adherence with F/TDF for PrEP in cisgender women is less well characterized.

Objective

To characterize the effectiveness of F/TDF for PrEP and its relationship with adherence in cisgender women.

Design, Setting, and Participants

Data were pooled from 11 F/TDF PrEP postapproval studies conducted in 6 countries that included 6296 cisgender women aged 15 to 69 years conducted from 2012 to 2020. HIV incidence was evaluated according to adherence level measured objectively (tenofovir diphosphate concentration in dried blood spots or tenofovir concentration in plasma; n = 288) and subjectively (electronic pill cap monitoring, pill counts, self-report, and study-reported adherence scale; n = 2954) using group-based trajectory modeling.

Exposures

F/TDF prescribed orally once a day. HIV incidence was analyzed in subgroups based on adherence trajectory.

Main Outcomes and Measures

HIV incidence.

Results

Of the 6296 participants, 46% were from Kenya, 28% were from South Africa, 21% were from India, 2.9% were from Uganda, 1.6% were from Botswana, and 0.8% were from the US. The mean (SD) age at PrEP initiation across all studies was 25 (7) years, with 61% of participants being younger than 25 years. The overall HIV incidence was 0.72 per 100 person-years (95% CI, 0.51-1.01; 32 incident HIV diagnoses among 6296 participants). Four distinct groups of adherence trajectories were identified: consistently daily (7 doses/week), consistently high (4-6 doses/week), high but declining (from a mean of 4-6 doses/week and then declining), and consistently low (less than 2 doses/week). None of the 498 women with consistently daily adherence acquired HIV. Only 1 of the 658 women with consistently high adherence acquired HIV (incidence rate, 0.13/100 person-years [95% CI, 0.02-0.92]). The incidence rate was 0.49 per 100 person-years (95% CI, 0.22-1.08) in the high but declining adherence group (n = 1166) and 1.27 per 100 person-years (95% CI, 0.53-3.04) in the consistently low adherence group (n = 632).

Conclusions and Relevance

In a pooled analysis of 11 postapproval studies of F/TDF for PrEP among cisgender women, overall HIV incidence was 0.72 per 100 person-years; individuals with consistently daily or consistently high adherence (4-6 doses/week) to PrEP experienced very low HIV incidence.

Mycorrhization in trees: ecology, physiology, emerging technologies and beyond

Mycorrhization has been an integral part of plants since colonization by the early land plants. Over decades, substantial research has highlighted its potential role in improving nutritional efficiency and growth, development and survival of crop plants. However, the focus of this review is trees. Evidence have been provided to explain ecological and physiological significance of mycorrhization in trees. Advances in recent technologies (e.g., metagenomics, artificial intelligence, machine learning, agricultural drones) may open new windows to apply this knowledge in promoting tree growth in forest ecosystems. Dual mycorrhization relationships in trees and even triple relationships among trees, mycorrhizal fungi and bacteria offer an interesting physiological system to understand how plants interact with other organisms for better survival. Besides, studies indicate additional roles of mycorrhization in learning, memorizing and communication between host trees through a common mycorrhizal network (CMN). Recent observations in trees suggest that mycorrhization may even promote tolerance to multiple abiotic (e.g., drought, salt, heavy metal stress) and biotic (e.g. fungi) stresses. Due to the extent of physiological reliance, local adaptation of trees is heavily impacted by the mycorrhizal community. This knowledge opens the possibility of a non-GMO avenue to promote tree growth and development. Indeed, mycorrhization could impact growth of trees in nurserys and subsequent survival of the inoculated trees in field conditions. Future studies might integrate hyperspectral imaging and drone technologies to identify tree communities that are deficient in nitrogen and spray mycorrhizal spore formulations on them.

Gender Affirming Hormones Do Not Affect the Exposure and Efficacy of F/TDF or F/TAF for HIV Preexposure Prophylaxis: A Subgroup Analysis from the DISCOVER Trial

Purpose

Transgender women are disproportionately affected by HIV and are underutilizing preexposure prophylaxis (PrEP). The lower uptake of PrEP by transgender women may be, in part, owing to the perception that taking PrEP may lower the efficacy of gender-affirming hormone therapy (GAHT) or to provider concerns that GAHT may lower the efficacy of PrEP.

Methods

DISCOVER was a randomized, double-blind, noninferiority trial comparing emtricitabine (FTC, F) and tenofovir alafenamide (F/TAF) versus emtricitabine and tenofovir disoproxil fumarate (F/TDF) as PrEP among transgender women and cisgender men who have sex with men (MSM). This nested substudy of the DISCOVER trial compared the exposure of the active intracellular metabolites of FTC and tenofovir (TFV), FTC triphosphate (FTC-TP) and TFV diphosphate (TFV-DP), in peripheral blood mononuclear cells (PBMC) among transgender women receiving GAHT versus MSM within the F/TAF and F/TDF groups.

Results

Our results demonstrate that TFV-DP and FTC-TP levels in PBMC were comparable between transgender women on GAHT and MSM receiving F/TAF, and between transgender women on GAHT and MSM receiving F/TDF. TFV-DP concentrations remained above the EC90 of 40 fmol/106 cells across all groups. No clinically significant drug-drug interactions of GAHT were observed with either F/TAF or F/TDF in this subanalysis.

Conclusions

These findings are consistent with the clinical pharmacology of GAHT, FTC, TDF, and TAF reported in previous studies, and support the continued use of F/TAF and F/TDF for PrEP in transgender women.

Clinicaltrials.gov registration number: NCT02842086.

Health equity and gendered border blindness: an exploration of healthcare services at the international border in Rajasthan

OBJECTIVES

Citizens' access to health care and the delivery of the healthcare services is significantly affected by the spatiality of the regions and the connectedness of the elements of the healthcare system. This network of healthcare system, region and delivery of services faces myriad challenges in the borderland geography, which is characterised by accentuated military presence, poor physical infrastructure, disinterest of habitation near the border, lack of adequate, necessary and allied services such as schools and industry, social seclusion, migration etc. All these factors amalgamate to create an effect of gender-blind phenomenon as well as border-blind phenomenon. This is particularly acute for women and children.

STUDY DESIGN

A phenomenology research design has been used for the study. It encapsulates qualitative aspects of the views of those who experience marginalisation inclusive of gender-blind experiences. Marginalised women and frontline healthcare workers at the borderland were considered for the inquiry in this study. The study is a composite description of the phenomenon.

METHODS

The border districts of Rajasthan from the Radcliffe line of Rajasthan have been identified for the purpose of the study. Using narrative ethnography along with interviews, an examination was executed from health professionals and marginalised women to comprehend health care access and equity from the service provider's perspective as well as the beneficiary's perspective.

RESULTS

The study provides a range of attributions based on which it could be established that health inequities exist in bordering rural areas.

CONCLUSIONS

The study realises the geopolitical influence of the Radcliffe line, where borderlands are commonly vital to the continuum struggle between the centre and state. Yet, there remains a gap towards implementing various schemes and services due to varied reasons for access from main to far-off border areas, making the situation vulnerable from a resource deficiency point of view. The Health Equity Framework cannot meet Social Determinants of Health in borderland areas of Rajasthan.

CNS Control after First-Line Osimertinib in Patients with Metastatic EGFR-Mutant NSCLC

PURPOSE/OBJECTIVE(S)

Although osimertinib (osi) has excellent intracranial activity in EGFR-mutant metastatic non-small cell lung cancer (NSCLC), there is no consensus regarding whether to continue osi for central nervous system (CNS) control with second-line chemotherapy (chemo) at the time of systemic progression. We aimed to compare CNS outcomes after first-line osi in patients receiving second-line chemo with or without continuation of osi.

MATERIALS/METHODS

We retrospectively reviewed patients with EGFR-mutant NSCLC with brain metastases (BrM) at the time of initiating first-line osi who experienced progression and started second-line chemo. Cumulative incidence of local and distant CNS progression, and extracranial (EC) progression was calculated from time of second-line chemo initiation with death as a competing risk. Overall survival (OS) was analyzed using Kaplan-Meier.

RESULTS

We included 52 patients with a median follow up of 9.6 months (range 0.4-36.4). Median OS and CNS progression-free survival (PFS) from the time of starting second-line chemo was 12.5 months (95% CI 8.1-16.9), and 5.3 months (95% CI 3.35-7.26), respectively. The 1-year cumulative incidence of local, distant CNS progression, any CNS progression, and EC progression was 14.4% (95% CI 4.5-24.2), 42.8% (95% CI 22.8-56.8), 42.8% (95% CI 22.8-56.8) and 66.8% (95% CI 53.5-80.2), respectively. After progression on first-line osi, 25 (48.1%) and 27 patients (51.9%) continued and discontinued osi, respectively. Patients who continued osi had significantly higher BrM burden than those who did not, with 17 (68%), 3 (12%), and 5 (20%) versus 26 (96%), 0, and 1 (3.7%) patient having <10 or >11 parenchymal brain lesions, or leptomeningeal disease (LMD) at the time of second line therapy, respectively (p<0.01). In those who continued osi vs those who did not, median OS (10.8 vs 12.5 months; p = 0.37), median intracranial PFS (5.3 vs 4.8 months; p = 0.99), 1-year cumulative incidence of local (8.4% versus 20 % p = 0.26), and 1-year distant CNS progression (24.8% vs 60%; p = 0.08) was not significantly different. CNS complications such as symptomatic, hospitalizations, and steroid initiation for CNS disease, and progression of LMD were not significantly different between the two groups. Eventually, 10 patients underwent salvage RT post first-line osi and median time to salvage RT was 7.8 months (range 2-9.4). Of patients who underwent salvage RT, 2 patients (20%) had continued osi with second-line chemo. Twelve patients (44.4%) who did not continue osi eventually re-started osi for progressive disease.

CONCLUSION

Patients who continued osi had significantly higher BrM tumor burden. Despite these patients being at higher risk for CNS progression, time to CNS progression and incidence of CNS complications were not significantly different in the two cohorts. Patients who discontinued osi were more likely to undergo salvage RT. Continuation of osi may allow patients to defer salvage RT.

Operationalising targeted next-generation sequencing for routine diagnosis of drug-resistant TB

BACKGROUND

Phenotypic drug susceptibility testing (pDST) for Mycobacterium tuberculosis can take up to 8 weeks, while conventional molecular tests identify a limited set of resistance mutations. Targeted next-generation sequencing (tNGS) offers rapid results for predicting comprehensive drug resistance, and this study sought to explore its operational feasibility within a public health laboratory in Mumbai, India.

METHODS

Pulmonary samples from consenting patients testing Xpert MTB-positive were tested for drug resistance by conventional methods and using tNGS. Laboratory operational and logistical implementation experiences from study team members are shared below.

RESULTS

Of the total number of patients tested, 70% (113/161) had no history of previous TB or treatment; however, 88.2% (n = 142) had rifampicin-resistant/multidrug-resistant TB (RR/MDR-TB). There was a high concordance between resistance predictions of tNGS and pDST for most drugs, with tNGS more accurately identifying resistance overall. tNGS was integrated and adapted into the laboratory workflow; however, batching samples caused significantly longer result turnaround time, fastest at 24 days. Manual DNA extraction caused inefficiencies; thus protocol optimisations were performed. Technical expertise was required for analysis of uncharacterised mutations and interpretation of report templates. tNGS cost per sample was US$230, while for pDST this was US$119.

CONCLUSIONS

Implementation of tNGS is feasible in reference laboratories. It can rapidly identify drug resistance and should be considered as a potential alternative to pDST.

Clinical utility of target-based next-generation sequencing for drug-resistant TB

BACKGROUND: In high TB burden countries, access to drug susceptibility testing is a major bottleneck. Targeted next-generation sequencing (tNGS) is a promising technology for rapid resistance detection. This study assessed the role of tNGS for the diagnosis of drug-resistant TB (DR-TB).METHODS: A total of 161 samples from bacteriologically confirmed TB cases were subjected to tNGS using the Deeplex^® Myc-TB kit and sequenced using the MiSeq platform. These samples were also processed for conventional phenotypic DST (pDST) using 13 drugs on Mycobacteria Growth Indicator Tube and line-probe assays (MTBDRplus and MTBDRsl).RESULTS: There were 146 DR-TB and 15 drug-susceptible TB (DS-TB) samples. About 70% of patients with DR-TB had no previous TB treatment history. Overall, 88.2% had rifampicin-resistant/multidrug-resistant TB (RR/MDR-TB), 58.5% pre-extensively drug-resistant TB (pre-XDR-TB) and 9.2% had XDR-TB as defined by the WHO (2020). Around 8% (n = 13) of samples were non-culturable; however, identified 8 were resistant to first and second-line drugs using tNGS. Resistance frequency was similar across methods, with discordance in drugs less reliable using pDST or with limited mutational representation within databases. Sensitivities were aligned with literature reports for most drugs. We observed 10% heteroresistance, while 75% of strains were of Lineages 2 and 3.CONCLUSIONS: Programme data supported tNGS in the diagnosis of DR-TB for early treatment using individualised regimens.

Facilitating Next-Generation Pre-Exposure Prophylaxis Clinical Trials Using HIV Recent Infection Assays: A Consensus Statement from the Forum HIV Prevention Trial Design Project

Standard-of-care HIV pre-exposure prophylaxis (PrEP) is highly efficacious, but uptake of and persistence on a daily oral pill is low in many settings. Evaluation of alternate PrEP products will require innovation to avoid the unpractically large sample sizes in noninferiority trials. We propose estimating HIV incidence in people not on PrEP as an external counterfactual to which on-PrEP incidence in trial subjects can be compared. HIV recent infection testing algorithms (RITAs), such as the limiting antigen avidity assay plus viral load used on specimens from untreated HIV positive people identified during screening, is one possible approach. Its feasibility is partly dependent on the sample size needed to ensure adequate power, which is impacted by RITA performance, the number of recent infections identified, the expected efficacy of the intervention, and other factors. Screening sample sizes to support detection of an 80% reduction in incidence for 3 key populations are more modest, and comparable to the number of participants in recent phase III PrEP trials. Sample sizes would be significantly larger in populations with lower incidence, where the false recency rate is higher or if PrEP efficacy is expected to be lower. Our proposed counterfactual approach appears to be feasible, offers high statistical power, and is nearly contemporaneous with the on-PrEP population. It will be important to monitor the performance of this approach during new product development for HIV prevention. If successful, it could be a model for preventive HIV vaccines and prevention of other infectious diseases.

2059. Estimated Background HIV Diagnosis Rates among People Who Could Benefit from Pre-Exposure Prophylaxis (PrEP) at the Metropolitan Statistical Area (MSA) level in the United States, 2012-2019

Background

Identifying areas of high background HIV diagnosis rates (bHIV) is critical for future PrEP trials using counterfactual study designs to estimate efficacy and to facilitate effective implementation of HIV prevention interventions. In this study, we used a multiple data source model to estimate bHIV between 2012 and 2019 in people who could benefit from PrEP (PWBP) but are not taking PrEP to identify with greater precision areas of high HIV transmission at the Metropolitan Statistical Area (MSA) level. We compared bHIV in PWBP in PURPOSE2 (NCT04925752) trial sites to those in the DISCOVER trial (NCT02842086) to demonstrate how this approach can inform site selection in future PrEP clinical trials and support delivery of PrEP interventions.

Methods

Number of new HIV diagnoses, number of individuals with a PrEP indication, and person-time on PrEP or after HIV diagnosis (obtained from published surveillance data) and pharmacy claims data (IQVIA PharMetrics Plus) were used to calculate estimated bHIV in a multivariate Poisson regression model for PWBP in 108 MSAs and across states between 2012 and 2019.

Results

Overall, bHIV among PWBP decreased from 4.42 per 100 person-years (PY) (95% CI 4.38 – 4.47) in 2012 to 3.14 per 100 PY (95% CI 3.10 – 3.17) in 2019. However, bHIV among PWBP in MSAs with PURPOSE2 trial sites were consistently higher (from 4.69 per 100 PY [95% CI 4.56 – 4.81] in 2012 to 3.58 per 100 PY [95% CI 3.49 – 3.67] in 2019) compared to areas with DISCOVER-only sites (from 3.77 per 100 PY [95% CI 3.53 – 4.01] in 2012 to 2.83 per 100 PY [95% CI 2.63 – 3.03] in 2019; Figure 1A). Within states, we identified specific localities with high bHIV among PWBP, such as in Illinois where state level HIV diagnosis rate was 2.65 per 100 PY [95% CI 2.50 – 2.80] but as high as 6.04 per 100 PY [95% CI 5.67 - 6.40] in the MSA with a PURPOSE2 site (Figure 1B). Figure:Estimated background HIV diagnosis rates (bHIV) in people who could benefit from PrEP by MSAs selected by DISCOVER/PURPOSE2 trials (A) from 2012 to 2019 and (B) in 2019 in the US.

Conclusion

We found considerable variation in bHIV at the MSA level among PWBP who are not taking PrEP, including a concentration of MSAs in the Southeastern US with high rates of new HIV diagnosis. Our methodology for leveraging existing surveillance data to identify areas of high bHIV with greater precision may provide a valuable approach to support future counterfactual clinical trial designs and prioritize resources for delivery of PrEP services.

Disclosures

Melanie de Boer, PhD, Gilead Sciences: Employee|Gilead Sciences: Stocks/Bonds Jason Yuan, n/a, Gilead Sciences: Employee|Gilead Sciences: Stocks/Bonds Juan Yang, PhD, Gilead Sciences: Employee|Gilead Sciences: Stocks/Bonds Lillian Brown, MD, PhD, Gilead Sciences: Stocks/Bonds Carlo Hojilla, PhD, Gilead Sciences: Employee|Gilead Sciences: Stocks/Bonds Christoph C. Carter, MD, PhD, Gilead Sciences: Employee|Gilead Sciences: Employee|Gilead Sciences: Stocks/Bonds|Gilead Sciences: Stocks/Bonds Moupali Das, MD, Gilead Sciences: Employee|Gilead Sciences: Employee|Gilead Sciences: Stocks/Bonds|Gilead Sciences: Stocks/Bonds Li Tao, MD, PhD, Gilead Sciences: Employee|Gilead Sciences: Employee|Gilead Sciences: Stocks/Bonds|Gilead Sciences: Stocks/Bonds.

2088. Real-World Geographic Variations of HIV Diagnosis Rates among Individuals Prescribed and not Prescribed Oral HIV Pre-Exposure Prophylaxis (PrEP) Regimens in the United States

Background

Declines in the diagnoses of new HIV infections have been reported in geographic areas with higher uptake of PrEP among persons who would benefit from PrEP (PWBP). In the present analysis, we examined the rate of new HIV diagnoses in PWBP prescribed PrEP and those not prescribed PrEP in order to understand the current and potential impact of PrEP in differing geographies.

Methods

We estimated the rate of new HIV infections among PWBP not prescribed PrEP with a previously described model (Mera et al. 2019) using a combination of published reports and a claims database. HIV rates for individuals prescribed F/TAF or F/TDF (including brand and generic) for PrEP between 10/3/2019 (F/TAF approval) and 6/30/2021 were analyzed from claims data. For those prescribed PrEP, new infections included new HIV diagnosis or addition of HIV treatment within 10 days of PrEP discontinuation.

Results

Overall, the US HIV diagnosis rate was 61% lower among PWBP prescribed PrEP (1.33 per 100-person year [95%CI: 1.24 – 1.42]) compared to those not prescribed PrEP (3.38 [3.35 – 3.42]). New HIV diagnosis rates by state among PWBP not prescribed PrEP ranged from 0.41 (0.22 – 0.78) in Vermont to 9.96 (9.53 – 11.54) in Mississippi (Figure). The Southern US had the highest regional HIV diagnosis rate among PWBP not prescribed PrEP (4.20 [4.14 - 4.26], Table). HIV diagnosis rates by state among PWBP prescribed PrEP were lower, ranging from 0 to 2.40 (0.05 – 4.75). Eleven states had a greater than 85% lower HIV diagnosis rate among PWBP prescribed PrEP versus those who were not prescribed PrEP, and the greatest differences in diagnosis rates by PrEP prescription status were observed in the Southeastern US states. Figure:

2079. Comparison of Recency Assays to Estimate HIV Incidence in the SIENA (eStimating hIv incidEnce amoNg Agyw) Study in Uganda

Background

HIV-1 recent infection testing algorithms (RITAs) use recency assays to estimate population level HIV incidence rates (IRs), and are currently being employed in PrEP trials to estimate background HIV incidence rates (bHIV-IR). The SIENA study was conducted to determine the HIV incidence rate among young women in and around central and mid-western Uganda, and to assess the suitability of different recency assay platforms for use in determining bHIV-IR in future PrEP trials.

Methods

Diagnosis of HIV was confirmed by positive results on both the Alere Determine HIV-1/2 and Oraquick HIV-1/2 rapid tests. Positive samples were analyzed for recent infection using the Sedia HIV-1 Limiting Antigen Avidity Enzyme ImmunoAssay (LAg-EIA; Sedia Biosciences, Beaverton, OR) and the Sedia Asante HIV-1 Rapid Recency Assay (Asante; Sedia Biosciences). The Asante assay was performed by electronic reader (Asante-Reader) or visual read (Asante-Visual). VL was determined by COBAS TaqMan HIV-1 Test (LabCorp, Indianapolis, IN). HIV incidence was calculated based on previously determined MDRI and FRRs that were specific for the study population.

Results

Of 743 women screened, 191 were diagnosed with HIV, of whom 44 (23%) had a viral load of &lt; 75 copies/mL. The 3 recency assays identified between 43 and 57 samples as recent and between 35 and 37 samples when the VL cutoff of &lt; 75 copies/mL was used (Table). When no VL cutoff was used the calculated bHIV-IR was 17.9/100 person-years (PY) for the LAg-EIA, 12.8/100PY for the Asante-Reader and 20.3/100PY for the Asante-Visual. Using the VL cutoff, the calculated bHIV-IR was 11.4/100 PY with the LAg-EIA assay and 10.9/100 PY with the Asante-Reader. No MDRI or FRR for the Asante-Visual with a VL cutoff was available for calculation of the Asante-Visual HIV incidence.

Conclusion

When the RITA included a VL cutoff of 75 cp/mL, the LAg-EIA and Asante assays classified the number of recent and long-term infections similarly, resulting in comparable bHIV-IR results. Overall, these analyses support the use of these recency assays in the RITA to estimate the bHIV-IR in future PrEP trials. Our results demonstrate extremely high prevalence and incidence of HIV in young women in central and mid-western Uganda, highlighting the need for expanded HIV prevention options in these areas.

Disclosures

Stephanie Cox, BS, Gilead Sciences: Paid employee|Gilead Sciences: Stocks/Bonds Shelley N. Facente, PhD, MPH, CDC-funded TRACE program: Grant/Research Support|Gilead Sciences: Advisor/Consultant|Sedia Biosciences Corporation: Grant/Research Support Eduard Grebe, PhD, CDC-funded TRACE program: Grant/Research Support|Gilead Sciences: Advisor/Consultant|Sedia Biosciences Corp: Grant/Research Support Ramin Ebrahimi, MS, Gilead Sciences: Paid employee|Gilead Sciences: Stocks/Bonds Christoph C. Carter, MD, PhD, Gilead Sciences: Employee|Gilead Sciences: Employee|Gilead Sciences: Stocks/Bonds|Gilead Sciences: Stocks/Bonds Christian Callebaut, PhD, Gilead Sciences: Paid employee|Gilead Sciences: Stocks/Bonds Jared Baeten, MD, PhD, Gilead Sciences: Employee|Gilead Sciences: Stocks/Bonds Moupali Das, MD, Gilead Sciences: Employee|Gilead Sciences: Employee|Gilead Sciences: Stocks/Bonds|Gilead Sciences: Stocks/Bonds.

Proactive strategies to optimize engagement of Black, Hispanic/Latinx, transgender, and nonbinary individuals in a trial of a novel agent for HIV pre-exposure prophylaxis (PrEP)

INTRODUCTION

Black and Hispanic/Latinx cisgender men who have sex with men (MSM), transgender women, transgender men, and gender nonbinary (TGNB) individuals have been historically underrepresented in HIV pre-exposure prophylaxis (PrEP) clinical trials. There is an urgent need for ongoing engagement with communities that have been the most impacted by HIV and diverse representation in clinical trials. Here we describe strategic approaches undertaken in the PURPOSE 2 trial to optimize engagement of underrepresented individuals.

METHODS AND RESULTS

PURPOSE 2 is an ongoing Phase 3 trial evaluating the safety and efficacy of lenacapavir as PrEP in cisgender MSM and TGNB individuals. In PURPOSE 2, we used a multipronged approach aimed at enriching participation of underrepresented individuals. We conducted a review to identify evidence-informed recommendations from literature, engaged with stakeholders, and established the Global Community Advisory and Accountability Group (GCAG) to represent the needs of the community. Insights from stakeholders and GCAG members resulted in an expansion of the study population to include transgender men, gender nonbinary persons, and adolescents, and evaluation of population-specific outcomes. Feedback from stakeholders and GCAG members also informed investigator and site selection; these were selected based on prior experience working with persons from diverse racial, ethnic and gender identities, and estimates of local HIV incidence. Site selection was also expanded to include community-based clinics with services tailored towards Black, Hispanic/Latinx, and TGNB populations. We established a study-wide recruitment goal of 50% Black MSM and 20% Hispanic/Latinx MSM in US sites and 20% transgender women globally. Site-specific recruitment goals were also developed based on local demographics and HIV incidence. Mandatory trainings included Good Participatory Practice guidelines, gender inclusivity, and antiracism.

CONCLUSION

While further work is needed to achieve equitable representation, the strategies we describe may serve as a framework for future clinical trials.

TRIAL REGISTRATION

Clinical Trial Number: NCT04925752.

UK multi-centre retrospective study of the learning curve and relative performance of the rhythmia high density mapping system for atrial ablation

Funding Acknowledgements

Type of funding sources: Public hospital(s). Main funding source(s): University Hospital Southampton

Background

Rhythmia HDx® is a novel ultra-high density electroanatomical mapping system using an innovative 64 electrode basket catheter. A learning curve is a recognised phenomenon for any new technology and was examined in this study.

Purpose

Comparison of performance, long-term success, and complications using Rhythmia for atrial ablation in the UK.

Methods

Retrospective data collection from three centres across the UK from the introduction of Rhythmia. Patients were matched with controls who had undergone ablation using the well-established Carto3 mapping system. Assessed were: fluoroscopy, radiofrequency ablation and procedure times; acute and long term success, and complications.

Results

253 study patients with 253 controls were included. Significant correlations existed between procedural efficiency metrics and centre experience for de novo atrial fibrillation (AF) ablation (procedure time, Spearman’s ρ = -0.624; ablation time, ρ = -0.795), and de novo atrial flutter (AFlut) ablation (ablation time, ρ = -0.566; fluoroscopy time, ρ = -0.520). No such correlations existed for redo AF, redo AFlut, de novo atrial tachycardia (AT), or redo AT cases. For de novo AF and AFlut, procedural efficiency metrics were significantly improved after 10 procedures in each centre, (procedure time [AF only, p = 0.001], ablation time [AF, p &lt; 0.0005; AFlut p &lt; 0.0005] and fluoroscopy time [AFlut only, p = 0.0022]), and became comparable to controls (Figures 1 and 2). Acute success and long-term success did not see significant improvement with experience but were comparable to the control group. There was no relationship between experience and complications, which were comparable to Carto3 (3.6% in both groups).

Conclusion

A short learning curve exists with the use of Rhythmia HDx for standardised procedures (de novo AF / AFlut). Procedural performance improves and becomes comparable to Carto3 following 10 cases at each centre. Clinical outcomes at 6 and 12 months, and complications are not affected by this learning curve and remain comparable with controls.

848. Approaches to Optimize Recruitment of Historically Underrepresented Black and Hispanic/LatinX MSM, Transgender, and Gender Non-binary Individuals into the Lenacapavir for PrEP (PURPOSE 2) Trial

Background

Black and Hispanic/Latinx gay and other men who have sex with men (MSM), transgender women (TGW), transgender men (TGM), and gender nonbinary individuals (GNB) have been historically underrepresented in HIV prevention trials despite being disproportionately affected by the disease. Therefore, studies of pre-exposure prophylaxis (PrEP), a highly effective intervention for reducing HIV incidence, should include these individuals, and doing so would promote generalizability of the findings.

Methods

PURPOSE 2 (GS-US-528-9023) will evaluate a twice-yearly long-acting subcutaneous, first in class capsid inhibitor, lenacapavir, for PrEP in MSM, TGW, TGM, and GNB in the US, Brazil, Peru, and South Africa. The study team adopted a multifactorial approach to address historic underrepresentation. This included a literature review to assess successful evidence-based approaches for increasing enrollment of Black and Hispanic/ LatinX MSM, TG, and GNB individuals. We engaged with community and patient advocates as well as key stakeholders to solicit feedback prior to protocol development.

Results

We established a trial-specific Global Community Advisory Group and implemented their recommendations for site selection, investigator and staff diversity, and strong linkage with community-based organizations. We recruited new community-based research sites and principal investigators (PIs) to mirror historically underrepresented populations and emphasized mentorship of junior sub-Is by seasoned PIs to support enrollment and retention. We developed required trainings for all study and site staff on good participatory practices for PrEP, anti-racism and transgender cultural humility. We established recruitment goals of 50% Black and 20% Hispanic/LatinX MSM in the US, and 20% TGW study-wide. Our strategy to ensure achievement of these overall goals involves nuanced site-specific recruitment goals considering site capacity, local demographics, and HIV incidence data. We will review metrics weekly during enrollment and make any necessary adjustments.

Conclusion

Using novel approaches, we have carefully chosen with whom, where, and how we will collaborate to increase the diversity, equity, and inclusion in the PURPOSE 2 trial.

Disclosures

Michelle Cespedes, MD, MS, Gilead Sciences Inc. (Scientific Research Study Investigator, Advisor or Review Panel member, Research Grant or Support)GlaxoSmithKline (Scientific Research Study Investigator, Research Grant or Support) Jill Blumenthal, MD, Gilead Sciences (Grant/Research Support, Scientific Research Study Investigator) Karam Mounzer, MD, Epividian (Advisor or Review Panel member)Gilead Sciences Inc. (Consultant, Scientific Research Study Investigator, Research Grant or Support, Speaker’s Bureau)Janssen (Consultant, Research Grant or Support, Speaker’s Bureau)Merck (Research Grant or Support, Speaker’s Bureau)ViiV Healthcare (Consultant, Speaker’s Bureau) Moti Ramgopal, MD FACP FIDSA, Abbvie (Scientific Research Study Investigator, Speaker’s Bureau)Gilead (Consultant, Scientific Research Study Investigator, Speaker’s Bureau)Janssen (Consultant, Scientific Research Study Investigator, Research Grant or Support, Speaker’s Bureau)Merck (Consultant, Scientific Research Study Investigator)ViiV (Consultant, Scientific Research Study Investigator, Speaker’s Bureau) Ayana Elliott, DNP, APRN, FNP-C, NEA-BC, Gilead Sciences Inc. (Employee, Shareholder) A.C. Demidont, MD, Gilead Sciences Inc. (Employee, Shareholder) C. Chauncey Watson, MD, Gilead Sciences Inc. (Employee, Shareholder) Christoph C. Carter, MD, Gilead Sciences Inc. (Employee, Shareholder) Alex Kintu, MD, ScD, Gilead Sciences Inc. (Employee, Shareholder) Moupali Das, MD, Gilead Sciences Inc. (Employee, Shareholder) Jared Baeten, MD, PHD, Gilead Sciences Inc. (Employee, Shareholder) Onyema Ogbuagu, MD, Gilead Sciences Inc. (Scientific Research Study Investigator, Advisor or Review Panel member, Research Grant or Support, Other Financial or Material Support)ViiV Healthcare (Advisor or Review Panel member)

854. Long-term Outcomes of Participants on F/TAF for Pre-Exposure Prophylaxis: Results for 144 Weeks of Follow-Up in the DISCOVER Trial

Background

In DISCOVER, a multinational randomized controlled trial, F/TAF demonstrated noninferior efficacy compared to F/TDF for HIV prevention with improved bone mineral density and renal safety biomarkers at the primary endpoint (when all participants had reached 48 weeks and 50% had reached 96 weeks) and at week (W) 96, the end of the blinded phase. We now report W144 outcomes for participants who were randomized to F/TAF and continued F/TAF in the open-label extension (OLE) phase.

Methods

All participants who completed the randomized blinded phase could opt to receive F/TAF for at least 48 weeks in the OLE phase. We evaluated HIV incidence in participants on F/TAF through W144 and assessed changes in hip and spine bone mineral density (BMD) and in glomerular function (eGFR) from baseline to W144.

Results

2,080 of the 2,694 participants initially randomized to F/TAF opted into the OLE phase, and 1,933 were still on study drug through W144, thereby leading to a total of 7,885 person-years (PY) of follow-up on F/TAF. Eight participants taking F/TAF acquired HIV in the blinded phase and 3 in the OLE phase. Dried blood spot analyses on the 3 OL infections found tenofovir diphosphate levels consistent with low adherence. Genotypic resistance testing showed no relevant resistance mutations for the 3 new infections. Among participants taking F/TAF, HIV incidence was 0.16/100 PY (95% CI 0.06-0.33) at the primary endpoint, 0.16/100 PY (95% CI 0.07-0.31) through 96 weeks and 0.14/100 PY (95% CI 0.07-0.25) through 144 weeks. Participants taking F/TAF had increases in hip BMD (mean percentage change +0.54%) and in spine BMD (mean percentage change +1.02%) from baseline to W144 (Figure 1). Median eGFR increased over 144 weeks, with a median increase of 2.6 mL/min from baseline to week 144. Participants in the F/TAF arm gained a median 2.3 kg (IQR -0.9-5.8) over 3 years of follow up.

Figure 1. Changes in hip and spine bone mineral density and in eGFR through Week 144

Conclusion

The OLE of DISCOVER allowed for a long-term assessment (144 wks.) of F/TAF for PrEP. HIV incidence remained low with BMD and renal function parameters remaining stable through 144 weeks of follow-up. These findings demonstrate that F/TAF is a safe and effective option for long-term use in people who would benefit from PrEP.

Disclosures

Moti Ramgopal, MD FACP FIDSA, Abbvie (Scientific Research Study Investigator, Speaker’s Bureau)Gilead (Consultant, Scientific Research Study Investigator, Speaker’s Bureau)Janssen (Consultant, Scientific Research Study Investigator, Research Grant or Support, Speaker’s Bureau)Merck (Consultant, Scientific Research Study Investigator)ViiV (Consultant, Scientific Research Study Investigator, Speaker’s Bureau) Peter Ruane, MD, AbbVie (Consultant, Research Grant or Support)Allergan (Research Grant or Support)Gilead Sciences Inc. (Consultant, Research Grant or Support, Shareholder, Speaker’s Bureau)Merck (Consultant, Research Grant or Support)ViiV Healthcare (Consultant, Research Grant or Support) Yongwu Shao, PhD, Gilead Sciences Inc. (Employee, Shareholder) Ramin Ebrahimi, MSc, Gilead Sciences Inc. (Employee, Shareholder) Alex Kintu, MD, ScD, Gilead Sciences Inc. (Employee, Shareholder) Christoph C. Carter, MD, Gilead Sciences Inc. (Employee, Shareholder) Moupali Das, MD, Gilead Sciences Inc. (Employee, Shareholder) Jared Baeten, MD, PHD, Gilead Sciences Inc. (Employee, Shareholder) Cynthia Brinson, MD, Abbvie (Scientific Research Study Investigator)BI (Scientific Research Study Investigator)Gilead Sciences Inc. (Scientific Research Study Investigator, Advisor or Review Panel member, Speaker’s Bureau, Personal fees)GSK (Scientific Research Study Investigator)Novo Nordisk (Scientific Research Study Investigator)ViiV Healthcare (Scientific Research Study Investigator, Advisor or Review Panel member, Speaker’s Bureau) Peter Shalit, MD, PhD, Abbvie (Grant/Research Support)Gilead Sciences (Consultant, Grant/Research Support, Speaker’s Bureau)Glaxo Smithkline (Consultant, Grant/Research Support)Janssen (Consultant, Grant/Research Support, Speaker’s Bureau)Merck (Grant/Research Support, Speaker’s Bureau)Thera (Speaker’s Bureau)ViiV Healthcare (Speaker’s Bureau) Karam Mounzer, MD, Epividian (Advisor or Review Panel member)Gilead Sciences Inc. (Consultant, Scientific Research Study Investigator, Research Grant or Support, Speaker’s Bureau)Janssen (Consultant, Research Grant or Support, Speaker’s Bureau)Merck (Research Grant or Support, Speaker’s Bureau)ViiV Healthcare (Consultant, Speaker’s Bureau)

866. Adherence to F/TDF for PrEP in Dried Blood Spots and HIV Infection Rates: A Pooled Analysis of Global PrEP Studies

Background

The use of daily F/TDF for HIV pre-exposure prophylaxis (PrEP) substantially reduces HIV acquisition. Dried blood spot (DBS) tenofovir-diphosphate (TFV-DP) levels reflect TDF use over the past 6-8 weeks, providing an objective measure of adherence in people taking PrEP.

Methods

In a pooled analysis of 19 PrEP demonstration projects and clinical studies, 6,613 participants had at least one TFV-DP measurement in DBS and followed for at least 48 weeks and up to 96 weeks. We used a piecewise linear mixed-effects model to plot the least-square means with corresponding 95% confidence intervals (CI) of TFV-DP for adherence over time, and Poisson regressions to calculate HIV incidence rates (IR) by level of weighted average of TFV-DP.

Results

Of 6,613 participants, median age was 30 years (interquartile range 24−38), 5,449 (82%) were cisgender men, 806 (12%) were cisgender women, and 349 (5%) were transgender (316 transgender women, 2 transgender men, 31 unspecified). Adherence based on TFV-DP in DBS was consistently higher among participants who did not acquire HIV compared to those who did (Figure). Among all participants, 21%, 14%, 36%, and 29% has DBS consistent with taking < 2, 2−3, 4−6, and ≥7 tablets of F/TDF PrEP per week (Table). Sixty-nine participants acquired HIV, with a median PrEP exposure of 0.82 years and an overall HIV IR (95% CI) of 1.16 (0.92, 1.47) per 100 person years. There was a strong association between adherence and HIV incidence [among individuals who took < 2, 2−3, 4−6, and ≥7 tablets/week, the HIV IRs (95% CI) were 5.20 (4.03, 6.71), 0.38 (0.12, 1.18), 0.28 (0.12, 0.61), and 0.06 (0.01, 0.39), respectively. Overall IR (95% CI) of HIV infection among cisgender men was 1.25 (0.98, 1.60) per 100 patient-years. Four cisgender women and 2 transgender participants acquired HIV, corresponding to IRs (95% CI) of 0.71 (0.27, 1.90) and 0.63 (0.16, 2.53).

Adherence by TFV-DP in DBS for F/TDF users who acquired HIV compared to those who did not.

Note: ‘x’ on the Figure represents visit week when a new HIV infection was detected.

HIV incidence rates (95% confidence intervals) by adherence to PrEP measured by level of TFV-DP in DBS up to 96 weeks after PrEP Initiation

Conclusion

This diverse, multi-national pooled analysis of F/TDF PrEP use provides the largest assessment to date of the adherence-HIV incidence relationship in people taking F/TDF for PrEP. The results suggest a high background HIV incidence in the pooled cohort and high efficacy in those adherent to PrEP. These findings support ongoing efforts to increase PrEP use among people who would benefit.

Disclosures

Albert Liu, MD, MPH, Gilead Sciences (Individual(s) Involved: Self): Gilead has donated study drug for studies I have led., Grant/Research Support, Other Financial or Material Support, Research Grant or Support; IAS-USA (Individual(s) Involved: Self): Honorarium for manuscript writing, Other Financial or Material Support; Viiv Healthcare (Individual(s) Involved: Self): Grant/Research Support, Research Grant or Support Raphael J. Landovitz, MD, MSc, Gilead Sciences (Individual(s) Involved: Self): Consultant; Janssen (Individual(s) Involved: Self): Consultant; Merck Inc (Individual(s) Involved: Self): Consultant; Roche (Individual(s) Involved: Self): Consultant Jared Baeten, MD, PHD, Gilead Sciences Inc. (Employee, Shareholder) David Magnuson, PharmD, Gilead Sciences Inc (Employee, Shareholder) Moupali Das, MD, Gilead Sciences Inc. (Employee, Shareholder) Christoph C. Carter, MD, Gilead Sciences Inc. (Employee, Shareholder) Li Tao, MD, PhD, Gilead Sciences Inc (Employee, Shareholder)

855. Persistence on F/TAF versus F/TDF for HIV Pre-Exposure Prophylaxis: A Real-World Evidence Analysis in the United States

Background

Persistence to preexposure prophylaxis (PrEP) is an important determinant of its efficacy, but evidence on real-world persistence is lacking. This study assesses adherence to F/TDF and F/TAF for PrEP both in terms of discontinuation and re-initiation patterns.

Methods

We identified HIV-negative individuals in the United States who initiated F/TDF or F/TAF for PrEP between October 2019 and December 2020 from a de-identified prescription claims database; users taking generic F/TDF were excluded. Non-persistence was defined as a prescription fill gap of >30 days; discontinuation included switch from F/TDF to F/TAF or F/TAF to F/TDF. We used survival analyses to estimate persistence, Cox regressions to compare the hazard ratios (HR) of discontinuation, and logistic regression to compare the odds ratios of re-initiation after discontinuation.

Results

Among F/TAF users (N=82,402) median age at PrEP initiation was 35 years (interquartile range [IQR] 28−47) and median PrEP persistence was 4 months (IQR 1.8-8.9), compared to 31 years (IQR 25−40) and 2 months (IQR 1.0-3.8) for F/TDF users (N=48,501). PrEP persistence at 60 and 90 days was higher among F/TAF users than F/TDF users (Figure). F/TDF users were 2.5 times more likely to discontinue than F/TAF users, with more marked differences in older users than that in younger users (p for interaction between discontinuation and age group < 0.01, Table). We also observed a higher rate of discontinuation of F/TDF versus F/TAF if PrEP was prescribed by internal medicine or infectious disease physicians than by family medicine physicians (data not shown). After discontinuation, F/TAF users were 1.7 times more likely than F/TDF users to re-initiate PrEP; the association was not different by age.

Persistence rates of F/TAF and F/TDF for PrEP by time of PrEP initiation

Hazard ratios (HR) and corresponding 95% confidence intervals (CI) of non-persistence and odds ratios (OR) of re-initiation after discontinuation for users of F/TAF and F/TDF for PrEP in the US, Oct 2019 – Dec 2020

Conclusion

In this real-world analysis, the F/TAF for PrEP regimen was associated with higher persistence and re-initiation than F/TDF for PrEP. These findings underscore the dynamic nature of PrEP utilization in the real-world and the importance of interventions aimed at improving PrEP persistence and re-initiation in people who would benefit from PrEP.

Disclosures

Li Tao, MD, PhD, Gilead Sciences Inc (Employee, Shareholder) Valentina Shvachko, MS, Gilead Sciences Inc (Employee, Shareholder) Moupali Das, MD, Gilead Sciences Inc. (Employee, Shareholder) Christoph C. Carter, MD, Gilead Sciences Inc. (Employee, Shareholder) Jared Baeten, MD, PHD, Gilead Sciences Inc. (Employee, Shareholder) David Magnuson, PharmD, Gilead Sciences Inc (Employee, Shareholder)

Eruptive keratoacanthomas associated with dupilumab therapy

We would like to present the case of eruptive keratoacanthomas associated with dupilumab therapy, which occurred in an 85-year-old woman receiving biologic therapy for the treatment of atopic dermatitis. With the increasing prevalence of Dupilumab usage, this is an important potential complication of which clinicians should be aware.

Irreversibility Analysis of 3D Magnetohydrodynamic Casson Nanofluid Flow Past Through Two Bi-Directional Stretching Surfaces with Nonlinear Radiation

Application of the nanoparticles with different non-Newtonian base fluid has huge application in the industries where the heat generation or energy transform takes place and many such applications are designing the advanced energy system at high temperature, aerodynamics, energy extraction etc. In the present study, we have analyzed irreversibility for a 3-dimensional MHD, incompressible, electrically conducting Casson nanofluid flow through the two horizontal stretching surfaces. To make it more practical and broad, the flow field has been incorporated with porosity, suction/injection, non-linear radiation with fall velocity with convective heating conditions at the boundaries and entropy generation which is an important physical phenomenon in thermodynamics. Influence of imperative parameters of the flow field and physical parameters have discussed with the entropy generation. In a limiting case, a comparison made. It is observed that the suction phenomena boost up the local Nusselt and Sherwood number at the surface while restricted the skin friction. The non-Newtonian rheology (as Casson number) restricted the skin friction and the same phenomena observed for the local heat and mass transfer. The entropy boosts up with the enhancement of the magnetic parameter, temperature ratio and Brinkman number. Further nanoparticle concentration improve the thermal conductivity leads an improvement in the efficiency of the heat transfer takes place. With the augment in thermal radiation, magnetic parameter and Brinkman number, the entropy generation of the systems gets accelerated.

Long-term safety and efficacy of emtricitabine and tenofovir alafenamide vs emtricitabine and tenofovir disoproxil fumarate for HIV-1 pre-exposure prophylaxis: week 96 results from a randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND

In DISCOVER, a multinational, randomised controlled trial, emtricitabine and tenofovir alafenamide compared with emtricitabine and tenofovir disoproxil fumarate showed non-inferior efficacy for HIV prevention and improved bone mineral density and renal safety biomarkers at week 48. We report outcomes analysed after all participants had completed 96 weeks of follow-up.

METHODS

This study is an ongoing, randomised, double-blind, multicentre, active-controlled, phase 3, non-inferiority trial done at 94 community, public health, and hospital-associated clinics located in Europe and North America. Adult cisgender men and transgender women who have sex with men, both with a high risk of acquiring HIV as determined by self-reported sexual behaviour or recent sexually transmitted infections, were randomly assigned (1:1) to receive either emtricitabine and tenofovir alafenamide (200/25 mg) tablets daily, with matched placebo tablets (emtricitabine and tenofovir alafenamide group), or emtricitabine and tenofovir disoproxil fumarate (200/300 mg) tablets daily, with matched placebo tablets (emtricitabine and tenofovir disoproxil fumarate group). The primary efficacy outcome was incident HIV infection. Incidence of HIV-1 infection per 100 person-years was assessed when the last participant had completed 96 weeks of follow-up. This trial is registered with ClinicalTrials.gov, number NCT02842086.

FINDINGS

Between Sept 13, 2016, and June 30, 2017, 5387 participants were randomly assigned to receive emtricitabine and tenofovir alafenamide (n=2694) or emtricitabine and tenofovir disoproxil fumarate (n=2693), contributing 10 081 person-years of follow-up. At 96 weeks of follow-up, there were eight HIV infections in participants who had received emtricitabine and tenofovir alafenamide (0·16 infections per 100 person-years [95% CI 0·07-0·31]) and 15 in participants who had received emtricitabine and tenofovir disoproxil fumarate (0·30 infections per 100 person-years [0·17-0·49]). Emtricitabine and tenofovir alafenamide maintained its non-inferiority to emtricitabine and tenofovir disoproxil fumarate for HIV prevention (IRR 0·54 [95% CI 0·23-1·26]). Approximately 78-82% of participants reported taking study medication more than 95% of the time across all study visits. Rates of sexually transmitted infections remained high and similar across groups (21 cases per 100 person-years for rectal gonorrhoea and 28 cases per 100 person-years for rectal chlamydia). Emtricitabine and tenofovir alafenamide continued to show superiority over emtricitabine and tenofovir disoproxil fumarate in all but one of the six prespecified bone mineral density and renal biomarkers. There was more weight gain among participants who had received emtricitabine and tenofovir alafenamide (median weight gain 1·7 kg vs 0·5 kg, p<0·0001).

INTERPRETATION

Emtricitabine and tenofovir alafenamide is safe and effective for longer-term pre-exposure prophylaxis in cisgender men and transgender women who have sex with men.

FUNDING

Gilead Sciences.

Clinical efficacy of grape seed extract as an adjuvant to scaling and root planing in treatment of periodontal pockets

Grape seed extract (GSE), a naturally producing polyphenolic compound, is found to be a potent hostmodulatory agent and considered for management of periodontal disease. Its anti-bacterial, antioxidant, and anti-inflammatory property may aid in achieving periodontal health. To assess the clinical efficacy of GSE in adjunct to scaling and root planing (SRP) in healing of periodontal pockets. The present study was a longitudinal, parallel design, randomized clinical trial. Seventy-two patients (mean age 39.2±8.6 years) with periodontal pockets were randomly divided into two groups; Test group received intra-pocket delivery of GSE with SRP and Control group received SRP alone. The clinical parameters like Plaque Index (PI), Gingival Index (GI), Probing Depth (PD) and Relative Attachment Level (RAL) were recorded at baseline and 3 months. 64 patients completed the study. Test group at the end of 3 months had statistically significant reduced PD (p=0.002) and RAL (p=0.01). No significant difference was observed for PI and GI at the end of 3 months. Intra-pocket application of GSE with SRP could be beneficial in management of periodontal pockets.

Two-dose emtricitabine/tenofovir alafenamide plus bictegravir prophylaxis protects macaques against SHIV infection

OBJECTIVES

Current prophylaxis options for people at risk for HIV infection include two US FDA-approved daily pre-exposure prophylaxis (PrEP) regimens and guidelines for a 2-1-1 event-driven course specifically for men who have sex with men. Despite this, PrEP use rates remain suboptimal, and additional PrEP options may help to improve uptake among diverse populations. Here, we evaluated protective efficacy of two-dose PrEP and two-dose postexposure prophylaxis (PEP) schedules with emtricitabine (FTC)/tenofovir alafenamide (TAF) with or without bictegravir (BIC) in an SHIV macaque model.

METHODS

Macaques received one oral dose of 200 mg emtricitabine, 25 mg tenofovir alafenamide and 25-100 mg of bictegravir to establish pharmacokinetic profiles of each drug either in the plasma or the peripheral blood mononuclear cells. Protective efficacy of multiple two-dose PrEP and PEP schedules with FTC/TAF with or without bictegravir was then assessed in two repeat low-dose rectal SHIV challenge studies.

RESULTS

The data revealed over 95% per-exposure risk reduction with FTC/TAF PrEP initiated 2 h before the exposure, but a loss of significant protection with treatment initiation postexposure. In contrast, FTC/TAF plus BIC offered complete protection as PrEP and greater than 80% per-exposure risk reduction with treatment initiation up to 24 h postexposure.

CONCLUSIONS

Together, these results demonstrate that two-dose schedules can protect macaques against SHIV acquisition and highlight the protective advantage of adding the integrase inhibitor bictegravir to the reverse transcriptase inhibitors emtricitabine and tenofovir alafenamide as part of event-driven prophylaxis.

Weight Change Following Antiretroviral Therapy Switch in People with Viral Suppression: Pooled Data from Randomized Clinical Trials

BACKGROUND

We sought to identify factors associated with weight gain in randomized clinical trials of antiretroviral (ART) switch.

METHODS

We explored the effects of demographic factors, clinical characteristics, and ART on weight gain in a pooled analysis of 12 prospective clinical trials, wherein virologically-suppressed people with HIV (PWH) were randomized to switch or remain on stable baseline regimen (SBR).

RESULTS

Both PWH randomized to switch ART (n=4,166) and those remaining on SBR (n=3150) gained weight. Median weight gain was greater in those who switched (1.6 [IQR -.05, 4.0] vs 0.4 [IQR -1.8, 2.4] kg at 48 weeks, p<0.0001), with most weight gain occurring in the first 24 weeks after switch. Among baseline demographic and clinical characteristics, only younger age and lower baseline body mass index were associated with any or ≥10% weight gain. 4.6% gained ≥10% weight by week 48 (6.4% of switch and 2.2% of SBR), the greatest risk with switch from EFV to RPV or EVG/c, and switch from TDF to TAF. Switch from ABC to TAF was associated with less weight gain than switch from TDF to TAF, and was not associated with increased risk for ≥10% weight gain.

CONCLUSIONS

Moderate weight gain after ART switch was common, and usually plateaued by 48 weeks. Baseline ART was a predictor of post-switch weight gain: participants switching off EFV and TDF had the greatest weight gain. The biological mechanisms underlying the differential effects of switching ART agents on weight and associated clinical implications require further study.

Using the adherence-efficacy relationship of emtricitabine and tenofovir disoproxil fumarate to calculate background hiv incidence: a secondary analysis of a randomized, controlled trial

INTRODUCTION

Randomized trials of new agents for HIV pre-exposure prophylaxis (PrEP) compare against emtricitabine and tenofovir disoproxil fumarate (F/TDF), without a placebo group. We used the well-characterized adherence-efficacy relationship for F/TDF to back-calculate the (non-PrEP) counterfactual background HIV incidence (bHIV) in a randomized trial of a novel PrEP agent and estimate comparative efficacy (to counterfactual bHIV).

METHODS

The DISCOVER trial (ClinicalTrials.gov: NCT02842086) randomized 5387 men who have sex with men (MSM) and transgender women who have sex with men and demonstrated non-inferiority of emtricitabine and tenofovir alafenamide (F/TAF) to F/TDF (HIV incidence rate ratio [IRR] 0·47, 95% CI: 0·19 to 1.15). Tenofovir diphosphate (TFV-DP) levels in dried blood spots (DBS) were assessed for all diagnosed with HIV and in a random 10% of the cohort. We used a Bayesian model with a diffuse prior distribution, derived from established data relating tenofovir diphosphate levels to HIV prevention efficacy. This prior, combined with the F/TDF seroconversion rate and tenofovir diphosphate levels in DISCOVER, yielded Bayesian inferences on the counterfactual bHIV.

RESULTS

There were six versus 11 postbaseline HIV infections (0.14 vs. 0.25/100 person-years [PY]) on F/TAF and F/TDF respectively. Of the 11 on F/TDF, 10 had low, none had medium and one had high tenofovir diphosphate levels; among HIV-negative controls, 5% of the person-time years had low, 9% had medium and 86% had high TFV-DP levels. A non-informative prior distribution for counterfactual bHIV, combined with the prior for TFV-DP level-efficacy relationship, yielded a posterior counterfactual bHIV of 3·4 infections/100 PY (0.80 Bayesian credible interval [CrI] 1·9 to 5·9), which suggests a median HIV efficacy of 96% (0.95 CrI [88% to 99%]) for F/TAF and 93% (0.95 CrI [87% to 96%]) for F/TDF compared to bHIV.

CONCLUSIONS

Based on the established connection of drug concentrations to PrEP prevention efficacy, a Bayesian framework can be used to estimate a synthetic non-PrEP control group in randomized, active-controlled PrEP trials that include a F/TDF-comparator group.

Compassionate Use of Remdesivir in Children With Severe COVID-19

OBJECTIVES

Remdesivir shortens time to recovery in adults with severe coronavirus disease 2019 (COVID-19), but its efficacy and safety in children are unknown. We describe outcomes in children with severe COVID-19 treated with remdesivir.

METHODS

Seventy-seven hospitalized patients <18 years old with confirmed severe acute respiratory syndrome coronavirus 2 infection received remdesivir through a compassionate-use program between March 21 and April 22, 2020. The intended remdesivir treatment course was 10 days (200 mg on day 1 and 100 mg daily subsequently for children ≥40 kg and 5 mg/kg on day 1 and 2.5 mg/kg daily subsequently for children <40 kg, given intravenously). Clinical data through 28 days of follow-up were collected.

RESULTS

Median age was 14 years (interquartile range 7-16, range <2 months to 17 years). Seventy-nine percent of patients had ≥1 comorbid condition. At baseline, 90% of children required supplemental oxygen and 51% required invasive ventilation. By day 28 of follow-up, 88% of patients had a decreased oxygen-support requirement, 83% recovered, and 73% were discharged. Among children requiring invasive ventilation at baseline, 90% were extubated, 80% recovered, and 67% were discharged. There were 4 deaths, of which 3 were attributed to COVID-19. Remdesivir was well tolerated, with a low incidence of serious adverse events (16%). Most adverse events were related to COVID-19 or comorbid conditions. Laboratory abnormalities, including elevations in transaminase levels, were common; 61% were grades 1 or 2.

CONCLUSIONS

Among 77 children treated with remdesivir for severe COVID-19, most recovered and the rate of serious adverse events was low.

New TB drugs for the treatment of children and adolescents with rifampicin-resistant TB in Mumbai, India

SETTING: Médecins Sans Frontières (MSF) clinic in Mumbai, India.OBJECTIVE: To determine the final treatment outcomes, culture conversion and adverse events (AEs) during treatment among children and adolescents (0-19 years) with rifampicin-resistant tuberculosis (RR-TB) who received ambulatory injectable-free treatment, including bedaquiline (BDQ) and/or delamanid (DLM) during September 2014-January 2020.DESIGN: This was a retrospective cohort study based on review of routinely collected programme data.RESULTS: Twenty-four patients were included; the median age was 15.5 years (min-max 3-19) and 15 (63%) were females. None were HIV-coinfected. All had fluoroquinolone resistance. Twelve received treatment, including BDQ and DLM, 11 received DLM and one BDQ. The median exposure to BDQ (n = 13) and DLM (n = 23) was 82 (IQR 80-93) and 82 (IQR 77-96) weeks, respectively. Seventeen (94%) patients with positive culture at baseline (n = 18) had negative culture during treatment; median time for culture-conversion was 7 weeks (IQR 5-11). Twenty-three (96%) had successful treatment outcomes: cured (n = 16) or completed treatment (n = 7); one died. Eleven (46%) had 17 episodes of AEs. Two of 12 serious AEs were associated with new drugs (QTcF >500 ms).CONCLUSION: Based on one of the largest global cohorts of children and adolescents to receive new TB drugs, this study has shown that injectable-free regimens containing BDQ and/or DLM on ambulatory basis were effective and well-tolerated among children and adolescents and should be made routinely accessible to these vulnerable groups.

Weight Gain Following Initiation of Antiretroviral Therapy: Risk Factors in Randomized Comparative Clinical Trials

Background

Initiation of antiretroviral therapy (ART) often leads to weight gain. While some of this weight gain may be an appropriate return-to-health effect, excessive increases in weight may lead to obesity. We sought to explore factors associated with weight gain in several randomized comparative clinical trials of ART initiation.

Methods

We performed a pooled analysis of weight gain in 8 randomized controlled clinical trials of treatment-naive people living with human immunodeficiency virus (HIV) initiating ART between 2003 and 2015, comprising >5000 participants and 10 000 person-years of follow-up. We used multivariate modeling to explore relationships between demographic factors, HIV disease characteristics, and ART components and weight change following ART initiation.

Results

Weight gain was greater in more recent trials and with the use of newer ART regimens. Pooled analysis revealed baseline demographic factors associated with weight gain including lower CD4 cell count, higher HIV type 1 RNA, no injection drug use, female sex, and black race. Integrase strand transfer inhibitor use was associated with more weight gain than were protease inhibitors or nonnucleoside reverse transcriptase inhibitors (NNRTIs), with dolutegravir and bictegravir associated with more weight gain than elvitegravir/cobicistat. Among the NNRTIs, rilpivirine was associated with more weight gain than efavirenz. Among nucleoside/nucleotide reverse transcriptase inhibitors, tenofovir alafenamide was associated with more weight gain than tenofovir disoproxil fumarate, abacavir, or zidovudine.

Conclusions

Weight gain is ubiquitous in clinical trials of ART initiation and is multifactorial in nature, with demographic factors, HIV-related factors, and the composition of ART regimens as contributors. The mechanisms by which certain ART agents differentially contribute to weight gain are unknown.

Nature of sorption of trivalent arsenic on novel iron oxyhydroxide stabilized starch/OMMT composite: A mechanistic approach

Materials which are chemically, energetically and operationally acceptable for arsenic water treatment are highly required. In this study a hybrid material (SICC) of aminated starch, oxyhydroxide of iron and OMMT clay has been demonstrated for arsenic treatment. This new material was highly efficient in arsenic water treatment which could reduce arsenic concentration far below detection limits. All binding interactions during material preparation and arsenic sorption were exclusively characterized with FT-IR, XRD and other spectroscopic tools. A molecular modeling on the basis of density functional theory was carried out to verify the above findings. Influence of material dose, treatment time, initial ion concentration, varying temperatures, etc., on extent of sorption was studied in detail. The thermodynamic parameters viz. ΔG (>-11 kJ/mol), ΔH (42.48 kJ/mol), ΔS (177.6 JK^-1 mol^-1) and E a (59.16 kJ/mol) determined the feasibility of the process, its endothermic behavior and most importantly the chemical nature of the sorption accompanied by ion-exchange to some extent. The sorption followed a monolayer chemisorption pattern as determined by the Langmuir model (R² = 0.973, R L = 0.081) with a q_max = 2.04 at 303 K. The binding of As(III) on the material was governed by a pseudo second order kinetic model.

103. Persistence on F/TDF for HIV Pre-exposure Prophylaxis: Insights from Real-world Evidence

Background

Background: Daily F/TDF is highly effective for HIV pre-exposure prophylaxis (PrEP). Prior studies have found that women and people of younger age have lower adherence and lower persistence on PrEP, yet real-world evidence describing persistence associated with other clinical characteristics and the patterns of persistence is limited.

Methods

Methods: We identified 313,526 HIV-1 negative individuals in the United States who initiated F/TDF for PrEP between January 1, 2012 and December 31, 2019 from a de-identified prescription claims database. PrEP users were defined as non-persistent if a gap in prescription fills &gt;30 days was detected. We used survival analyses to estimate the persistence rate by year of PrEP initiation, and Cox regressions adjusting for multiple demographic and clinical characteristics to determine hazard ratios and corresponding 95% confidence interval of non-persistence for PrEP.

Results

Results: Among the 313,526 PrEP users with a median age at PrEP initiation of 35 years of age (interquartile range, IQR, 26−43), 88% were men (median days of persistence = 118, IQR 30−316 days) and 12% were women (median 30 days, IQR 30−92 days). PrEP persistence at 30, 60 and 90 days increased over time, reaching the highest levels in 2019 (Figure). In a multivariate analysis, younger age, female sex, and non-white race were associated with higher risk of non-persistence (Table). We also observed associations of a 5% lower rate of non-persistence if PrEP was prescribed by internal medicine or infectious disease physicians than by family medicine physicians, and a 13% lower rate of non-persistence associated prescriptions ordered from mail-order pharmacies than prescriptions of retail pharmacies. Finally, history of bone fracture or renal dysfunction prior to PrEP initiation were associated with a 13% and 9% higher rate of non-persistence, respectively.

Figure. F/TDF for PrEP persistence rates over time.

Conclusion

This study demonstrates that persistence on F/TDF for PrEP has improved over time, and identifies several characteristics associated with non-persistence, including age, sex, race/ethnicity, prescriber specialty, type of pharmacy, and history of bone fracture or renal dysfunction. These findings can help to inform interventions aimed at improving PrEP persistence in people at risk of HIV.

Disclosures

Li Tao, MD, PhD, Gilead Sciences Inc (Employee) Valentina Shvachko, n/a, Gilead Sciences Inc (Employee) Robertino Mera, MD, PhD, Gilead Sciences Inc (Employee) Moupali Das, MD, MPH, Gilead Sciences Inc (Employee) Christoph Carter, MD, PhD, Gilead Sciences Inc (Employee) David Magnuson, PharmD, Gilead Sciences Inc (Employee)

985. Impact of Age and Medical Comorbidities on Renal Outcomes in the DISCOVER Trial

Background

In DISCOVER, emtricitabine/tenofovir alafenamide (F/TAF) was noninferior to F/tenofovir disoproxil fumarate (TDF) for preexposure prophylaxis (PrEP) in men who have sex with men and transgender women, with a superior renal laboratory profile. The differential impact of F/TAF and F/TDF on renal parameters among older individuals and those with medical comorbidities is unknown.

Methods

DISCOVER randomized participants 1:1 to daily blinded F/TAF or F/TDF. We examined renal outcomes at week 48 including estimated glomerular filtration rate (eGFR) by Cockcroft-Gault, β2 microglobulin (M):Creatinine (Cr) and retinol binding protein (RBP):Cr ratios (markers of proximal renal tubular function), and discontinuations due to investigator reported study drug-related renal adverse events (AEs).

Results

Median age was 34 years (yrs)(range 18-76), with 12.5% vs 10.9% < 25yrs, 12.2% vs 14.4% ≥ 50yrs, and 1.1% vs 0.9% > 65yrs for F/TAF and F/TDF, respectively. The prevalence of medical comorbidities at baseline were; eGFR < 90mL/min= 9.1% vs 9.3%, diabetes= 2.9% vs 3.3%, and hypertension= 10.5 vs 11.1%, for F/TAF and F/TDF, respectively. eGFR changes by age category and medical comorbidity status are found in the Table. Forty participants had study drug-related renal AEs; 14 with F/TAF and 26 with F/TDF. Of these, 25% were > 50yrs, 20% had baseline eGFR < 90mL/min, 7.5% had history of diabetes, and 22.5% had history of hypertension. β2M:Cr and RBP:Cr changes were more favorable in participants receiving F/TAF, with greater magnitude of difference in older participants (data not shown).

Table.

Conclusion

The DISCOVER trial allows for a large single variable comparison of the two tenofovir prodrugs in the absence of underlying HIV infection and in the absence of third antiretroviral agents. F/TAF was associated with favorable changes in renal biomarkers regardless of age or medical comorbidity. Participants ≥50yrs or with comorbidities were proportionately more likely to develop study drug related renal AEs, but these were present in the minority of cases.

Disclosures

Eric Daar, MD, BMS (Consultant)Gilead Sciences Inc. (Consultant, Grant/Research Support, Scientific Research Study Investigator)Janssen (Consultant)Merck (Consultant, Grant/Research Support)Teva (Consultant)Theratechnology (Consultant)Viiv Healthcare (Consultant, Grant/Research Support) Jason Brunetta, MD, AbbVie (Consultant)Gilead Sciences Inc. (Consultant, Grant/Research Support, Scientific Research Study Investigator, Speaker’s Bureau, Other Financial or Material Support, Conference attendance sponsorship)Janssen (Other Financial or Material Support, Conference attendance sponsorship)Merck (Consultant, Speaker’s Bureau, Other Financial or Material Support, Conference attendance sponsorship)Viiv Healthcare (Consultant, Speaker’s Bureau, Other Financial or Material Support, Conference attendance sponsorship) Eric Cua, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) David Asmuth, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Christoph C. Carter, MD, Gilead Sciences Inc. (Employee, Shareholder) Yongwu Shao, PhD, Gilead Sciences Inc. (Employee, Shareholder) Pamela Wong, MPH, Gilead Sciences Inc. (Employee, Shareholder) Ramin Ebrahimi, MSc, Gilead Sciences Inc. (Employee, Shareholder) Moupali Das, MD, Gilead Sciences Inc. (Employee, Shareholder) Diana M. Brainard, MD, Gilead Sciences (Employee) Amanda Clarke, MD, Gilead Sciences Inc. (Consultant, Scientific Research Study Investigator, Other Financial or Material Support, Conference attendance sponsorship)Viiv Healthcare (Consultant, Other Financial or Material Support, Conference travel sponsorship)

995. Safety and Efficacy of F/TAF and F/TDF for PrEP in DISCOVER Participants Taking F/TDF for PrEP at Baseline

Background

DISCOVER is an ongoing trial comparing emtricitabine plus tenofovir alafenamide (F/TAF) or tenofovir disoproxil fumarate (F/TDF) for HIV pre-exposure prophylaxis (PrEP). DISCOVER included some participants already taking F/TDF for PrEP at baseline (BL) creating a unique opportunity to study outcomes after switching from F/TDF to F/TAF.

Methods

Men who have sex with men and transgender women at risk of HIV were randomized to receive blinded daily F/TAF or F/TDF and followed for at least 96 weeks; participants taking BL F/TDF for PrEP could enroll without a washout period. Laboratory assessments included estimated glomerular filtration rate (eGFR), markers of renal proximal tubular function (RBP and β2M to creatinine ratios), and fasting cholesterol levels; these were analyzed by 2-sided Wilcoxon rank sum test. Bone mineral density (BMD) was assessed in a subset of participants and analyzed by ANOVA.

Results

905 of 5387 (16.8%) participants were on BL F/TDF for PrEP for a median duration of 399 days; baseline characteristics are found in Table 1. There was one HIV infection among BL PrEP users, in a participant randomized to F/TDF who had intermittent low adherence. Participants on BL PrEP randomized to F/TAF had improvements in eGFR and markers of proximal tubular function compared to F/TDF. Median change in BMD was not statistically different for BL PrEP users assigned to F/TAF vs F/TDF, however de novo F/TAF participants had improved BMD profiles compared to F/TDF. BL PrEP users in the F/TAF arm had increases in LDL cholesterol (median +6mg/dL) compared to F/TDF, while changes in HDL and total:HDL ratio were similar. Lipid-modifying agent (LMA) initiation in BL PrEP users was more frequent in the F/TAF arm, while LMA initiation in de novo PrEP participants was similar between arms (Table 2).

Table 1. Characteristics of DISCOVER participants

Conclusion

HIV incidence was low in participants taking BL PrEP. Participants who switched from F/TDF to F/TAF had improvements in renal biomarkers. There was no statistical difference in BMD among BL PrEP users, although numbers were small. The observed lipid changes in BL PrEP users are consistent with the LDL and HDL suppressive effect of TDF, and the small but higher rate of LMA initiation with F/TAF is likely related to withdrawal of this effect.

Disclosures

Thomas Campbell, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Amanda Clarke, MD, Gilead Sciences Inc. (Consultant, Scientific Research Study Investigator, Other Financial or Material Support, Conference attendance sponsorship)Viiv Healthcare (Consultant, Other Financial or Material Support, Conference travel sponsorship) Benoit Trottier, MD, AbbVie (Grant/Research Support, Other Financial or Material Support, Personal fees)Bristol-Myers Squibb (Grant/Research Support, Other Financial or Material Support, Personal fees)Gilead Sciences Inc. (Grant/Research Support, Scientific Research Study Investigator, Other Financial or Material Support, Personal fees)Janssen (Grant/Research Support, Other Financial or Material Support, Personal fees)Merck (Grant/Research Support, Other Financial or Material Support, Personal fees)Viiv Healthcare (Grant/Research Support, Other Financial or Material Support, Personal fees) Christoph C. Carter, MD, Gilead Sciences Inc. (Employee, Shareholder) Yongwu Shao, PhD, Gilead Sciences Inc. (Employee, Shareholder) Ramin Ebrahimi, MSc, Gilead Sciences Inc. (Employee, Shareholder) Moupali Das, MD, Gilead Sciences Inc. (Employee, Shareholder) Diana M. Brainard, MD, Gilead Sciences (Employee) Jay Gladstein, MD, Gilead Sciences Inc. (Scientific Research Study Investigator)

999. Using the F/TDF Adherence-Efficacy Relationship to Calculate Background HIV incidence: Results from the DISCOVER trial

Background

RRandomized trials of new PrEP agents compare to oral emtricitabine+tenofovir disoproxil fumarate (F/TDF) and do not have a placebo arm. We used the well-characterized adherence-efficacy relationship for F/TDF from iPrEX OLE, to back-calculate the (non-PrEP) background HIV incidence (bHIV) in the F/TDF arm of DISCOVER and estimate comparative efficacy (to bHIV).

Methods

TDISCOVER is an ongoing randomized active-controlled trial in 5,387 men who have sex with men and transgender women that demonstrated non-inferiority of F+tenofovir alafenamide (F/TAF) to F/TDF (IRR 0.47 (95% CI 0.19, 1.15). TFV-DP levels in DBS were assessed for all diagnosed with HIV and in a randomized subset of 10%. We used a Bayesian model with a prior distribution, derived from iPrEx OLE, relating TFV-DP levels to HIV prevention efficacy: eg TFV-DP levels of < 350 (low), 350 to < 700 (medium) and ≥700 (high) fmol/punch were assumed to provide 0%, 86% and 98% HIV protection, respectively. This prior, combined with F/TDF seroconversion rate and TFV-DP levels, yields Bayesian inferences on the bHIV. In R, STAN was used to sample 10,000 realizations from the posterior distribution.

Results

There were 6 vs. 11 post-baseline HIV infections (0.14 v. 0.25 per 100 person-years [PY]) on F/TAF and F/TDF. Of the 11 on F/TDF, 10 had low, 0 had medium, and 1 had high TFV-DP levels; among HIV-negative controls, 5% of the person-time had low, 9% had medium, and 86% had high TFV-DP levels. A non-informative prior distribution for bHIV, combined with the prior for TFV-DP level-efficacy relationship, yielded a posterior bHIV incidence [0.80 Bayesian credible interval (CrI)] of 3.4/100 [1.9, 6.0/100] PY; which suggests a median F/TAF efficacy [0.95 CrI] of 96% [88%,99%] and 93% [87%,96%] for F/TDF compared to bHIV. If we chose a conservative prior distribution for bHIV of 1.0/100 PY, the model yields a median posterior bHIV [0.80 CrI] of 2.8/100 [1.7, 4.7/100] PY; which suggests a median efficacy [0.95 Cr] of 95% [86%, 99%] for F/TAF and 92% [86%, 67%] for F/TDF compared to bHIV with corresponding number of HIV infections averted of 117 and 114, respectively (Figure).

Figure.

Conclusion

The F/TDF adherence-efficacy relationship can be used to back-calculate bHIV incidence in MSM/TW PrEP trials and assess the efficacy of new PrEP agents compared to bHIV.

Disclosures

David V. Glidden, MD, Gilead Sciences Inc. (Other Financial or Material Support, Personal fees) David T. Dunn, MD, Gilead Sciences Inc. (Other Financial or Material Support, Personal fees)Viiv Healthcare (Other Financial or Material Support, Personal fees) Moupali Das, MD, Gilead Sciences Inc. (Employee, Shareholder) Ramin Ebrahimi, MSc, Gilead Sciences Inc. (Employee, Shareholder) Lijie Zhong, PhD, Gilead Sciences Inc. (Employee, Shareholder) Oliver T. Stirrup, MD, Gilead Sciences Inc. (Other Financial or Material Support, Personal fees) Peter L. Anderson, PharmD, Gilead Sciences Inc. (Other Financial or Material Support, Personal fees)

Understanding demand for, and feasibility of, centre-based child-care for poor urban households: a mixed methods study in Dhaka, Bangladesh

Background

Centre-based child-care has potential to provide multiple health and development benefits to children, families and societies. With rapid urbanisation, increasing numbers of low-income women work with reduced support from extended family, leaving a child-care vacuum in many low- and middle-income countries. We aimed to understand perceptions of, and demand for, centre-based child-care in Dhaka, Bangladesh among poor, urban households, and test the feasibility of delivering sustainable centre-based child-care.

Methods

We used sequential mixed methods including a household survey (n = 222) and qualitative interviews with care-givers (n = 16), community leaders (n = 5) and policy-makers (n = 5). We co-produced and piloted a centre-based child-care model over ten-months, documenting implementation. A co-design focus group with mothers, parents’ meetings, and qualitative interviews with child-care centre users (n = 5), non-users (n = 3), ex-users (n = 3) and staff (2) were used to refine the model and identify implementation issues.

Results

We found 24% (95% CI: 16,37%) of care-givers reported turning-down paid work due to lack of child-care and 84% (95% CI:74, 91%) reported wishing to use centre-based child-care and were willing to pay up to 283 Takka (~$3.30) per month. Adjusted odds of reported need for child-care among slum households were 3.8 times those of non-slum households (95% CI: 1.4, 10). Implementation highlighted that poor households needed free child-care with food provided, presenting feasibility challenges. Meta-inference across quantitative and qualitative findings identified the impact of the urban environment on child-care through long working hours, low social capital and fears for child safety. These influences interacted with religious and social norms resulting in caution in using centre-based child-care despite evident need.

Conclusion

Sustainable provision of centre-based care that focuses on early childhood development requires subsidy and careful design sensitive to the working lives of poor families, particularly women and must respond to the dynamics of the urban environment and community values. We recommend increased research and policy focus on the evaluation and scale-up of quality centre-based child-care, emphasising early-childhood development, to support low-income working families in urban areas.

Gluconeogenic fructose-1,6-bisphosphatase from the mature sporocarps of common aquatic ferns: partial purification and basic characterization of this enzyme from Marsilea minuta (Polypodiopsida)

The present communication reports substantial activity of gluconeogenic fructose-1,6-bisphosphatase (FBPase; EC 3.1.3.11) in three common heterosporous aquatic ferns (Marsilea minuta, Salvinia natans, and Azolla pinnata) and also describes a protocol for its partial purification from mature sporocarps of Marsilea minuta. The cytosolic FBPase, obtained from Marsilea minuta, Salvinia natans, and Azolla pinnata was recognized as gluconeogenic enzyme due to its drastic catabolic inactivation in presence of externally administered glucose and its insensitivity towards photosynthetic light illumination. Cytosolic gluconeogenic FBPase was partially purified from mature sporocarps of Marsilea minuta to about 22-fold over homogenate following low-speed centrifugation (11, 400 × g), 30–80% ammonium sulfate fractionation followed by subsequent chromatography using matrices like CM-Cellulose, Sephadex G-200, and Ultrogel AcA 34. The profile of partially purified FBPase in PAGE under non-denaturing condition was recorded. The enzyme activity increased linearly with respect to protein concentration to about 100 µg and with respect to time up to 75 minutes. Temperature optimum was found at 35 °C. The effect of substrate concentration and kinetic analyses for FBPase were carried out using D-fructose-1,6-bisphosphate (D-FBP, the substrate) in the range of 0.0 to 1.0 mM at an interval of 0.1 mM concentration. The Km value for D-FBP of FBPase was 0.06129 mM and Vmax was 4525 nmole Pi released (mg)-1 protein h-1 as determined by nonlinear regression kinetics using Prism 8 software (Graph Pad). The enzyme was functional in a constricted pH range of 7.0 to 8.0, giving maxima at pH 7.5. This cytosolic enzyme was significantly stimulated by Mg2+ and strongly inhibited by Hg2+, Cu2+ and Zn2+.

Compassionate Use of Remdesivir in Pregnant Women with Severe Covid-19

Background

Remdesivir is efficacious for severe coronavirus disease 2019 (COVID-19) in adults, but data in pregnant women are limited. We describe outcomes in the first 86 pregnant women with severe COVID-19 who were treated with remdesivir.

Methods

The reported data span 21 March to 16 June 2020 for hospitalized pregnant women with polymerase chain reaction–confirmed severe acute respiratory syndrome coronavirus 2 infection and room air oxygen saturation ≤94% whose clinicians requested remdesivir through the compassionate use program. The intended remdesivir treatment course was 10 days (200 mg on day 1, followed by 100 mg for days 2–10, given intravenously).

Results

Nineteen of 86 women delivered before their first dose and were reclassified as immediate “postpartum” (median postpartum day 1 [range, 0–3]). At baseline, 40% of pregnant women (median gestational age, 28 weeks) required invasive ventilation, in contrast to 95% of postpartum women (median gestational age at delivery 30 weeks). By day 28 of follow-up, the level of oxygen requirement decreased in 96% and 89% of pregnant and postpartum women, respectively. Among pregnant women, 93% of those on mechanical ventilation were extubated, 93% recovered, and 90% were discharged. Among postpartum women, 89% were extubated, 89% recovered, and 84% were discharged. Remdesivir was well tolerated, with a low incidence of serious adverse events (AEs) (16%). Most AEs were related to pregnancy and underlying disease; most laboratory abnormalities were grade 1 or 2. There was 1 maternal death attributed to underlying disease and no neonatal deaths.

Conclusions

Among 86 pregnant and postpartum women with severe COVID-19 who received compassionate-use remdesivir, recovery rates were high, with a low rate of serious AEs.

A case of solitary kidney with duplex collecting systems and renal vascular variants in an adult male cadaver

We describe a unique solitary kidney with duplex collecting system and vascular variation observed in an 86-year-old white male formaldehyde- and phenol-fixed cadaver during routine academic dissection. The left renal fossa was empty with an intact adrenal gland, and the right renal fossa contained a fused renal mass with apparent polarity between the superior and inferior regions and two renal pelves converging into a single ureter. There were three right renal arteries supplying the renal mass; the superior and middle arteries were noted to be postcaval and the inferior artery was precaval. There were also two right renal veins draining into the inferior vena cava and following a regional distribution with the superior vein draining the inferior portion of the renal mass. Despite generally being asymptomatic, the detection of renal anatomical variants is clinically important for appropriate patient management and surgical interventions.