Emtricitabine-Triphosphate in Dried Blood Spots as a Marker of Recent Dosing

Measurements of tenofovir-diphosphate and emtricitabine-triphosphate concentrations in dried blood spots of people receiving pre-exposure prophylaxis for HIV with co-formulated tenofovir disoproxil fumarate and emtricitabine

BACKGROUND/PURPOSE(S)

Data regarding the concentrations of tenofovir-diphosphate (TFV-DP) and emtricitabine-triphosphate (FTC-TP) in the Asian population receiving pre-exposure prophylaxis (PrEP) for HIV with tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC) (TDF/FTC) are limited, and the associations between the frequency of TDF/FTC administration and drug concentration among people receiving on-demand PrEP remain unclear.

METHODS

Fifty-seven participants receiving daily TDF/FTC and 113 participants receiving on-demand TDF/FTC were enrolled in this study. The concentrations of TFV-DP and FTC-TP were measured in dried blood spots using liquid chromatography‒mass spectrometry.

RESULTS

Thirty-six (62.2 %) daily PrEP users and 38 (33.6 %) on-demand PrEP users achieved TFV-DP concentrations ≥700 fmol/punch. Higher proportions of undetectable FTC-TP were observed in participants whose TFV-DP concentrations were ≤350 fmol/punch, regardless of the frequency of TDF/FTC administration. In participants who used on-demand PrEP, the TFV-DP and FTC-TP concentrations were moderately correlated with the TDF/FTC tablets taken when sampling was performed within 12-24 h after the last dose of TDF/FTC (R = 0.63, p = 0.006 and R = 0.75, p = 0.0005). In addition, on-demand PrEP users who had received 8 tablets within the last 28 days had a median TFV-DP concentration similar to that of those participants who had received 16 tablets (544.6 vs. 556.9 fmol/punch, p > 0.99).

CONCLUSIONS

These results underscore the importance of well-controlled sampling times for obtaining reliable TFV-DP and FTC-TP concentrations to estimate the adherence and effectiveness of on-demand PrEP.

Cellular pharmacology of tenofovir alafenamide and emtricitabine in neutrophils and platelets in people with and without HIV

BACKGROUND

Previous studies have primarily focused on nucleos(t)ide reverse transcriptase inhibitor pharmacology in peripheral blood mononuclear cells (PBMCs) and erythrocytes via dried blood spots (DBS), but not other major blood cells.

OBJECTIVES

Our objectives were to describe and compare the concentrations of tenofovir-diphosphate (TFV-DP) and emtricitabine-triphosphate (FTC-TP) in DBS, PBMCs, neutrophils, and platelets in people with HIV (PWH) and people without HIV (PWOH).

METHODS

DBS, PBMCs, neutrophils, and platelets were isolated from whole blood drawn from PWH and PWOH receiving tenofovir alafenamide and emtricitabine. TFV-DP and FTC-TP concentrations were quantified using LC-MS/MS in each cell type. Linear regression models controlled for time on drug, adherence, and time since last dose, where applicable, to determine geometric mean percent differences (95% confidence interval) by HIV status and estimated half-lives.

RESULTS

Data were available in 13 PWH (96% male) and 30 PWOH (53% male). Compared with PWOH, TFV-DP in DBS was 48.9% (15.6%, 91.9%) higher and FTC-TP in platelets was 36.3% (4.5%, 77.7%) higher; TFV-DP in platelets also trended higher [43.5% (-3.24%, 113%)]. No other cell types significantly differed by HIV status. TFV-DP and FTC-TP demonstrated the longest half-lives in neutrophils, followed by PBMCs and then platelets. After normalizing to cell volume, both drugs accumulated from greatest to least in PBMCs, neutrophils, platelets, and erythrocytes across both PWH and PWOH.

CONCLUSIONS

Our findings highlight differential drug disposition across cell types that also vary by serostatus in DBS and platelets. The mechanisms and implications of these findings require additional research.

A Cross-Biomeasure Study to Optimize Antiretroviral Adherence Estimation

BACKGROUND

Incomplete adherence to daily tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) reduces effectiveness. Adherence biomeasures (ie, drug concentrations in biological specimen) are more accurate than self-report. TDF/FTC's intracellular active metabolites (tenofovir-diphosphate; TFVdp and FTC-triphosphate; FTCtp) can be quantified in different types of blood samples to estimate adherence. To optimize adherence estimation, we investigated approaches to measure TFVdp and FTCtp in 4 blood matrices.

METHODS

Twelve HIV-negative, healthy volunteers were enrolled in a single-center, open-label, 3-phase, directly observed therapy study. LC-MS/MS methods quantified TFVdp/FTCtp in dried blood spots, volumetrically accurate microsampling, upper layer packed cells, and peripheral blood mononuclear cells (PBMCs). Noncompartmental analysis estimated half-lives and accumulation ratios. Correlations characterized relationships between clinical variables and exposure. Regression models were fit to determine concentrations associated with <4 and ≥4 doses/week; correct classification percentages were determined.

RESULTS

Terminal half-life estimates of 3-4 vs 15-22 days distinguished between moderate-term (FTCtp in all samples; TFVdp in PBMCs) versus long-term (TFVdp in red blood cell-containing matrices) measures. Model-derived thresholds accurately categorized <4 and ≥4 doses/week when including both metabolites for 14- and 28-day dosing periods (81%-91% and 82%-85%, respectively). Within each classification and regression trees analyses containing both moderate- and long-term measures, dried blood spots exhibited highest accuracy to predict stable (74%-94%) and changing (42%-47%) adherence patterns.

CONCLUSIONS

We demonstrate higher accuracy of moderate-term biomeasures to classify adherence over a 14-day period compared with long-term biomeasures to classify adherence over a 28-day period. Combined moderate- and long-term biomeasures predicted stable and changing adherence patterns, with dried blood spots exhibiting highest accuracy.

High recent PrEP adherence with point-of-care urine tenofovir testing and adherence counselling among young African women: results from the INSIGHT cohort

INTRODUCTION

Adolescent girls and young women (AGYW) account for two-thirds of new HIV infections in Africa. African AGYW have had high uptake of oral HIV pre-exposure prophylaxis (PrEP) but low adherence, which might be improved by point-of-care adherence monitoring with tailored counselling.

METHODS

From August 2022 to July 2023, we conducted a PrEP demonstration project with sexually active AGYW ages 16-30 years from 20 sites in South Africa, Eswatini, Kenya, Malawi, Uganda and Zambia. Participants were offered oral tenofovir-based PrEP at enrolment and followed up at 1, 3 and 6 months. PrEP adherence was assessed by a point-of-care qualitative lateral flow urine tenofovir (TFV) assay indicating PrEP use in the prior 4 days, which accompanied real-time adherence counselling that incorporated urine TFV results when testing was available (70.8% of month 1, 35.3% of month 3 and 83.9% of month 6 visits). We estimated overall adherence, correcting for missing test results, and analysed the association of having received urine TFV results at month 1 or 3 with subsequent urine TFV test positivity, using modified Poisson regression.

RESULTS

Of the 3087 AGYW enrolled, the median age was 24 years (interquartile range 21-27), 75.7% were from South Africa, 2878 (93.2%) initiated PrEP at enrolment and 107 (3.5%) after enrolment. Visit retention was 92.0-96.2% for months 1, 3 and 6, and 2518 (90.1%) exited the study with a PrEP refill. Adherence, based on the point-of-care urine tenofovir test positivity rate, was estimated as 72%, 71% and 65% at months 1, 3 and 6, respectively. Women who received one prior urine TFV test had a 42% higher likelihood of a subsequent positive urine TFV test (adjusted odds ratio, OR = 1.42, 95% confidence interval, CI 1.27-1.60), and those having received two prior tests had a 67% higher likelihood (adjusted OR = 1.67; 95% CI 1.41-1.98). Observed HIV incidence was 1.38/100 person-years (95% CI 0.97-2.08).

CONCLUSIONS

Oral PrEP uptake, recent adherence and persistence were high in a multisite cohort of young African women over 6 months of follow-up. The use of a novel point-of-care tenofovir assay with tailored real-time adherence counselling was associated with increased adherence to PrEP at subsequent visits, warranting further study.

CLINICAL TRIALS REGISTRATION

clinicaltrials.gov NCT05746065.

Point-of-care urine tenofovir test predicts future HIV preexposure prophylaxis discontinuation among young users

BACKGROUND

Young men who have sex with men and transgender women (YMSM/TGW) have disproportionately high HIV incidence and lower preexposure prophylaxis (PrEP) adherence. Point-of-care (POC) urine tenofovir (TFV) rapid assay (UTRA) testing permits real-time monitoring for nonadherence within clinical settings. We performed UTRA testing among PrEP users to examine the relationship between low PrEP adherence and future PrEP discontinuation, and the accuracy of POC testing compared to gold-standard liquid chromatography tandem mass spectrometry (LC/MS/MS).

METHODS

YMSM/TGW participants ( n  = 100) were recruited during a daily PrEP visit. Logistic regression models analyzed the relationship between the primary predictor of urine POC assay results (cutoff 1,500 ng/ml) and the primary outcome of PrEP discontinuation, defined as no PrEP follow-up or prescription within 120 days.

RESULTS

Overall, 19% of participants had low urine TFV and 21% discontinued PrEP, while 11% of participants self-reported low PrEP adherence (<4 pills per week), which was only 43% sensitive/84% specific in predicting low TFV levels and was not associated with PrEP discontinuation. Low urine TFV level predicted PrEP discontinuation [adjusted odds ratio (AOR) 6.1; 95% confidence interval (CI): 1.4-11; P  = 0.005] and was 71% sensitive/90% specific for discontinuation after 120 days. Compared to LC/MS/MS, UTRA testing had a 98% positive and 100% negative predictive value.

CONCLUSIONS

In a sample of YMSM/TGW on daily PrEP, POC UTRA testing predicted PrEP discontinuation more accurately than self-reported adherence, with high predictive values compared to LC/MS/MS. UTRA testing may be a clinical tool for directing preventive interventions towards those likelier to discontinue PrEP despite ongoing HIV vulnerability.

Determination of intracellular tenofovir-diphosphate and emtricitabine-triphosphate concentrations in dried blood spots for pre-exposure prophylaxis adherence

OBJECTIVES

We measured the intracellular concentrations of tenofovir-diphosphate (TFV-DP) and emtricitabine-triphosphate (FTC-TP) in dried blood spots (DBS) for pre-exposure prophylaxis (PrEP) adherence using sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS).

METHODS

A total of 191 DBS were obtained from 85 participants who were receiving tenofovir disoproxil fumarate (TDF; 300 mg) and emtricitabine (FTC; 200 mg) as PrEP at the Sexual Health Clinic, National Center for Global Health and Medicine, Tokyo, Japan. DBS punch (3 mm) added to 25 μL of 50% methanol and 400 μL of internal standard solution was used for solid phase extraction. Chromatographic separation was achieved on an Atlantis Premier BEH C18 AX Column (50 mm × 2.1 mm i.d.; particle size 1.7 μm) using gradient elution (flow rate: 0.6 mL/min); injection volume: 7 μL and run time: 5.5 min. Calibration curves for the two drugs were linear in the range 0.05-12.5 ng/punch.

RESULTS

We determined the intracellular TFV-DP and FTC-TP concentrations in 191 DBS obtained from 85 patients administered with TDF and FTC as PrEP. The analytical performance data (calibration curve and QC samples) for all the analytical runs met the acceptance criteria. Intracellular concentrations of TFV-DP and FTC-TP in the DBS remained stable for at least 24 h after oral administration.

CONCLUSIONS

A multiplex LC-MS/MS method was successfully developed for DBS, which can be useful for monitoring the levels of TFV-DP and FTC-TP in individuals receiving PrEP.

Patterns of daily oral HIV PrEP adherence among people who inject drugs in Ukraine: an analysis of biomarkers

INTRODUCTION

Daily oral HIV pre-exposure prophylaxis (PrEP) with tenofovir/emtricitabine (TDF/FTC) is recommended for people who inject drugs (PWID) but coverage is low. The real-life effectiveness of PrEP among PWID is unknown as previous studies were conducted in controlled settings and mainly relied on self-report. Analysis of PrEP metabolites-tenofovir diphosphate (TFVdp) and emtricitabine triphosphate (FTCtp)-offers an objective measure of adherence.

METHODS

To analyse longitudinal patterns of PrEP adherence among PWID in Ukraine, we used data from a community-based implementation trial conducted in Kyiv between July 2020 and March 2021 to test the efficacy of SMS reminders to improve adherence. Among 199 enrolled participants, 156 (78.4%) were retained through 6 months. Based on TFVdp/FTCtp levels assessed at 3 and 6 months, we identified groups with various adherence patterns (adherent at ≥2 doses/week, improved, worsened, non-adherent). Correlates of adherence were analysed using multinomial logistic regression.

RESULTS

Most participants (53.8%, n = 84/156) had no detectable metabolites at both assessments; 7.1% (n = 11/156) were consistently taking ≥2 doses/week; 1.3% (n = 2/156) were consistently taking ≥4 doses/week; 13.5% (n = 21/156) exhibited improved and 21.8% (n = 34/156) had worsened adherence at 6 compared to 3 months. "White coat compliance" (increased dosing prior to assessment) was common. Consistent adherence was associated with SMS reminders, younger age, employment, lower income, longer injection drug use duration, recent high-risk injecting (receptive syringe sharing, using pre-filled syringe, back- or front-loading, container sharing), absence of overdose in the past 6 months, perceived HIV risk through sexual intercourse and higher PrEP self-efficacy. Alcohol consumption was associated with inconsistent PrEP use. Groups with improved and worsened adherence did not differ.

CONCLUSIONS

Daily oral PrEP may not achieve the desired effectiveness among PWID as a standalone intervention, calling for testing of alternative PrEP formulations and innovative integrated risk reduction strategies, especially in the context of HIV epidemics associated with injection drug use in eastern Europe and central Asia and the public health crisis in Ukraine caused by the war with Russia. SMS reminders may be effective among PWID who prioritize PrEP. Our findings offer practical guidance in identifying PWID who are likely to benefit from PrEP and those who need additional support.

Intimate Partner Violence and Adherence to PrEP and ART Among Ugandan HIV Serodifferent Couples

BACKGROUND

Intimate partner violence (IPV) is associated with increased risk of HIV acquisition and reduced engagement in HIV care. There is limited understanding of the ways in which IPV exposure and other maladaptive relationship dynamics may influence adherence to antiretroviral treatment (ART) and pre-exposure prophylaxis (PrEP) for individuals in committed, HIV serodifferent partnerships.

METHODS

We used binomial generalized linear mixed-effect regression models to evaluate the association between IPV exposure and ART/PrEP adherence among members of serodifferent couples in Uganda. Secondarily, we assessed the association between relationship powerlessness and ART/PrEP adherence.

RESULTS

We enrolled and followed both partners in 149 heterosexual serodifferent couples. The partner living with HIV was female in 64% of couples. IPV exposure was associated with low ART adherence (15% vs. 5% in quarters with no IPV, odds ratio: 4.78, 95% confidence interval: 1.48 to 15.42), but not low PrEP adherence (33% vs. 36%, P = 0.69). Among HIV-negative individuals, those reporting moderate relationship powerlessness were less likely to have poor PrEP adherence compared with those with low relationship powerlessness (20% vs. 30%, odds ratio: 0.57, 95% confidence interval: 0.36 to 0.90). We observed no association between relationship powerlessness and ART adherence.

CONCLUSIONS

We found that IPV exposure was associated with low adherence to ART and that relationship powerlessness was associated with good adherence to PrEP. These findings contribute to the evidence base outlining the influence of IPV and relationship power on ART/PrEP adherence for individuals in HIV serodifferent unions.

Ex-vivo rectal tissue infection with HIV-1 to assess time to protection following oral preexposure prophylaxis with tenofovir disoproxil/emtricitabine

OBJECTIVES

We wished to assess time to protection from HIV-1 infection following oral tenofovir disoproxil and emtricitabine (TDF/FTC) as preexposure prophylaxis (PrEP), using ex-vivo rectal tissue infections and drug concentration measures in blood and rectal tissue.

DESIGN/METHODS

Participants from the ANRS PREVENIR study (NCT03113123) were offered this sub-study after a 14-day wash-out. We used an ex-vivo model to evaluate rectal tissue HIV-1 susceptibility before and after PrEP, 2 h after two pills or 7 days of a daily pill of TDF/FTC. PrEP efficacy was expressed by the difference (after-before) of 14-day cumulative p24 antigen levels. TFV-DP and FTC-TP levels were measured in rectal tissue and PBMCs and correlated with HIV-1 infection.

RESULTS

Twelve and 11 men were analyzed in the 2 h-double dose and 7 days-single dose groups, respectively. Cumulative p24 differences after-before PrEP were -144 pg/ml/mg (IQR[-259;-108]) for the 2 h-double dose group ( P  = 0.0005) and -179 pg/ml/mg (IQR [-253;-86]) for the 7 days-single dose group ( P  = 0.001), with no differences between groups ( P  = 0.93). Rectal TFV-DP was below quantification after a double dose, but FTC-TP levels were similar to levels at 7 days. There was a significant correlation between rectal FTC-TP levels and p24 changes after a double dose ( R  = -0.84; P  = 0.0001).

CONCLUSION

Oral TDF/FTC provided similar protection against HIV-1 infection of rectal tissue 2 h after a double dose or 7 days of a daily dose. At 2 h, this protection seems driven by high FTC-TP concentrations in rectal tissue. This confirms the importance of combining TDF and FTC to achieve early protection.

Low daily oral PrEP adherence and low validity of self-report in a randomized trial among PWID in Ukraine

BACKGROUND

The efficacy of daily oral pre-exposure prophylaxis (PrEP) in preventing HIV transmission among people who inject drugs (PWID) was demonstrated over a decade ago. However, only a few studies among PWID have since measured PrEP adherence using laboratory markers.

METHODS

In this trial, we randomized recently injecting PWID in Kyiv, Ukraine, to receive daily oral TDF/FTC with or without SMS reminders. Enrollment and PrEP initiation took place at an HIV clinic. Subsequent visits at months 1, 3, and 6 were conducted at a community harm reduction center and included a structured interview, adherence counseling, PrEP dispensing, and dried blood spot collection. PrEP adherence was assessed using standard self-reported measures and TDF/FTC biomarkers.

RESULTS

A total of 199 PWID (99 SMS, 100 No-SMS) were enrolled, of whom 24 % were women, with a median age of 37. At month 6, 79.4 % (158/199) of participants were retained, with 84 % (133/158) reporting opioid injection and 20 % (31/158) reporting stimulant injection in the past 30 days. 77 % (122/158) reported taking >95 % of PrEP doses in the past month, and 87 % reported taking the last dose within 2 days. Tenofovir diphosphate was detected in 17 % (28/158) of participants, and emtricitabine triphosphate was detected in 25 % (40/158). Only 3 % (5/158) had metabolite levels indicative of consistent PrEP uptake at 4+ doses per week. There was no association between the SMS intervention and TDF/FTC metabolite detection.

CONCLUSION

Adherence to daily oral PrEP among actively injecting PWID, without daily supervision or incentives, was extremely low, despite supportive counseling and SMS reminders. We also observed a high rate of discordance between self-report and classification by a validated biomarker of adherence. Given the scarcity of evidence and emerging data suggesting low oral PrEP adherence among PWID, additional implementation studies with TDF/FTC biomarkers are needed to study whether a sufficient level of adherence to daily PrEP is attainable among PWID, especially as long-acting injectable PrEP offers a promising alternative.

Viral and host mediators of non-suppressible HIV-1 viremia

Non-suppressible HIV-1 viremia (NSV) is defined as persistent low-level viremia on antiretroviral therapy (ART) without evidence of ART non-adherence or significant drug resistance. Unraveling the mechanisms behind NSV would broaden our understanding of HIV-1 persistence. Here we analyzed plasma virus sequences in eight ART-treated individuals with NSV (88% male) and show that they are composed of large clones without evidence of viral evolution over time in those with longitudinal samples. We defined proviruses that match plasma HIV-1 RNA sequences as 'producer proviruses', and those that did not as 'non-producer proviruses'. Non-suppressible viremia arose from expanded clones of producer proviruses that were significantly larger than the genome-intact proviral reservoir of ART-suppressed individuals. Integration sites of producer proviruses were enriched in proximity to the activating H3K36me3 epigenetic mark. CD4+ T cells from participants with NSV demonstrated upregulation of anti-apoptotic genes and downregulation of pro-apoptotic and type I/II interferon-related pathways. Furthermore, participants with NSV showed significantly lower HIV-specific CD8+ T cell responses compared with untreated viremic controllers with similar viral loads. We identified potential critical host and viral mediators of NSV that may represent targets to disrupt HIV-1 persistence.

Urine point-of-care tenofovir test demonstrates strong predictive clinical and research utility

BACKGROUND

Preexposure prophylaxis (PrEP) significantly reduces HIV infection risk but is dependent on adherence. Available approaches to measuring adherence have limitations related to accuracy, cost, practicality, and timeliness. This study compared the performance of two methods implementable in clinics and research studies [interview and urine point of care (POC) assay] to the gold-standard for measuring recent and longer term adherence in dried blood spots (DBS).

METHODS

Participants were recruited from RADAR, a cohort study of young MSM, or via online advertisements. At 3 monthly visits, an interviewer administered 7-day timeline follow-back (TLFB) questionnaire, DBS samples were tested for tenofovir-diphosphate (TFV-DP) to estimate average dosing over the prior month and emtricitabine-triphosphate (FTC-TP) to assess recent dosing (past 2-3 days), and a urine POC TFV test to qualitatively assess recent adherence (past 4 days).

RESULTS

Eighty-three PrEP users contributed 163 observations. At visit 1, self-reported adherence was 86% (4+ doses in last 7 days), versus urine TFV (74%), DBS FTC-TP (76%), and DBS TFV-DP (69%). The objective measures of short-term adherence performed similarly well in predicting longer term adherence. In multivariable logistic regression analyses, the urine assay was a significant predictor of DBS TFV-DP (adjusted OR = 19.4, P  < 0.0001); self-report did not add significantly.

CONCLUSION

The urine POC TFV assay had excellent predictive values for adherence and self-report did not add significantly to prediction. The POC assay provides results in several minutes to enable same-visit counseling, requires no specialized training, and is projected to be low-cost.

Peer PrEP referral + HIV self-test delivery for PrEP initiation among young Kenyan women: study protocol for a hybrid cluster-randomized controlled trial

BACKGROUND

Oral HIV pre-exposure prophylaxis (PrEP) for HIV prevention is highly effective, but uptake remains low in Africa, especially among young women who are a priority population for HIV prevention services. HIV self-testing (HIVST) has been proven to increase HIV testing in diverse populations but has been underutilized to support linkage to HIV prevention services. Most young women who initiate PrEP in Africa do so through informal peer referral. We wanted to test a model of formalized peer referral enhanced with HIVST delivery among young Kenyan women.

METHODS

The Peer PrEP Trial is a two-arm hybrid effectiveness-implementation cluster-randomized controlled trial being conducted in central Kenya. Eligible participants (i.e., peer providers, n = 80) are women (≥ 16-24 years) refilling or initiating PrEP at public healthcare clinics who can identify at least four peers who could benefit from PrEP and not enrolled in another HIV study. Peer providers will be 1:1 randomized to (1) formal peer PrEP referral + HIVST delivery, where they will be encouraged to refer four peers (i.e., peer clients, ≥ 16-24 years) using educational materials and HIVST kits (two per peer client), or (2) informal peer PrEP referral, where they are encouraged to refer four peer clients using informal word-of-mouth referral. In both arms, peer providers will deliver a standard PrEP referral card with information on nearby public clinics delivering PrEP services. Peer providers will complete surveys at baseline and 3 months; peer clients will complete surveys at 3 months. Our primary outcome is PrEP initiation among peer clients, as reported by peer providers at 3 months. Secondary outcomes include PrEP continuation (any refilling), HIV testing (past 3 months), sexual behaviors (past month), and PrEP adherence (past month) among peer clients, as reported by both peer providers and clients at 3 months. Implementation outcomes will include participants' perceived acceptability, appropriateness, and feasibility of the intervention as well assessments of the intervention's fidelity and cost.

DISCUSSION

Evidence from this trial will help us understand how HIVST could support health systems by facilitating linkage to PrEP services among young women who could benefit in Kenya and similar settings.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04982250. Registered on July 29, 2021.

Tenofovir diphosphate in dried blood spots and HIV-1 resistance in South Africa

BACKGROUND

Suboptimal antiretroviral (ART) adherence can lead to virologic failure with consequent HIV-1 resistance. Tenofovir diphosphate (TFV-DP) in dried blood spots (DBS) is a powerful biomarker of cumulative adherence, predictive of future viremia. It has been associated with resistance in Persons With HIV (PWH) in South Africa and the US. We explored the relationship of TFV-DP concentrations with antiretroviral drug resistance at the time of treatment failure in SA.

METHODS

Adult PWH from health clinics in Cape Town, South Africa on efavirenz-based first-line ART containing tenofovir disoproxil fumarate (TDF) with an undetectable (< 50 copies/mL) HIV-1 viral load (VL) were prospectively enrolled in an observational cohort for 12 months. Monthly study visits included blood collection for HIV-1 VL and DBS for TFV-DP. The first confirmed viral breakthrough (VB) > 400 copies/mL triggered HIV-1 genotyping at the subsequent visit. An electronic adherence (EA) device monitored ART adherence in real-time, estimated as a percent for the 30-days prior to VB. Wilcoxon rank sum test was used to compare median [IQR] TFV-DP by genotype outcome.

RESULTS

Of 250 individuals, (n = 195, 78% women), 21 experienced VB, with a median of 5 [4;7] months on study, and a median EA of 33.3 [13.3;53.3]%. Demographic characteristics between those with and without VB were similar. Median VL at VB was 4.0 [3.2;4.5] log copies/mL. TFV-DP concentrations trended down towards the VB visit. Median TFV-DP concentrations were significantly higher in those HIV-1 genotype did not amplify due to being virally suppressed at the subsequent visit (n = 10; 380 [227-661] fmol/punch, p = 0.035; EA 45 [24.9; 59.2]%); than in those who were successfully genotyped with evidence of drug resistance (n = 5, 241 [150-247] fmol/punch, EA 20 [6.7;36.7]%) and in individuals who did not have resistance (n = 3, 39.9 [16.6; 93.9] fmol/punch; EA 33.3 [16-38]%). Three genotype collections were not done. Only non-nucleoside reverse transcriptase inhibitor-associated mutations were identified on resistance testing. (K103N, E138K, Y118H).

CONCLUSION

TFV-DP in DBS showed a step-wise inverse relationship with VB and drug resistance, with evidence of low cumulative ART adherence in PWH who developed antiretroviral resistance. Monitoring TFV-DP concentrations could be a valuable tool for predicting future VB and future resistance.

Substance Use and Adherence to HIV Pre-Exposure Prophylaxis in Studies Enrolling Men Who Have Sex with Men and Transgender Women: A Systematic Review

Optimal adherence to pre-exposure prophylaxis (PrEP) is critical, but challenging. Men who have sex with men and transgender women have high rates of HIV incidence and substance use. Substance use is associated with reduced adherence to other medications, but associations between substance use and adherence to PrEP are less clear. Thus, the current review 1) systematically evaluates the measurement of substance use and PrEP adherence in studies examining both and 2) summarizes reported findings. Peer-reviewed articles published between 2010 - April 2021 examining associations between substance use and PrEP adherence were reviewed. Fifty studies met inclusion criteria. Assessment of substance use (i.e., mostly via self-reports at baseline) and PrEP adherence (i.e., often via tenofovir diphosphate [TFV-DP] concentration levels at follow-up) varied considerably across studies. Many studies used categorical variables (e.g., substance use: yes/no). Studies using TFV-DP levels defined adherence consistently (i.e., TFV-DP ≥ 700 fmol/punch), with slight variations. Qualitative studies (n = 10) indicated that substance use (mainly alcohol) is related to poorer PrEP adherence. While quantitative findings to date are equivocal for alcohol, there is a pattern of findings linking stimulant use with poorer PrEP adherence. This review reveals four methodological gaps, which can be addressed in future research by: 1) use of uniform benchmarks for substance use measures, 2) prospective assessment for substance use, 3) use of continuous outcome variables wherever possible, and 4) more extensive consideration of potential confounders. Addressing these methodological gaps may help us reach more definitive conclusions regarding associations between substance use and PrEP adherence.

Application of novel plasma separation filter cards for quantification of nucleoside/nucleotide reverse transcriptase inhibitor di/triphosphates in dried blood spots using LC-MS

Background: A rapid and sensitive LC-MS method has been developed and validated for the quantification of nucleoside di/triphosphates using a novel plasma separation card (HemaSep). Materials & methods: Cards were spotted with whole blood and stored at -80°C. Metabolites were extracted using 70:30 MeOH:20% formic acid, followed by weak anion exchange SPE and eluted using a Biobasic-AX column. Quantification was performed using a triple quadrupole mass spectrometer with a calibration range of 1.25-250 pmol/sample. Results: The recovery of metabolites was high (>93%). Precision and accuracy were acceptable and metabolites remained stable on the card after 29 days (stored at ambient temperature). Conclusion: HemaSep dried blood spots are a useful microsampling tool and offer an alternative to liquid plasma as they maintain stability over time.

Application of the multiphase optimisation strategy (MOST) to optimise HIV prevention targeting people on medication for opioid use disorder (MOUD) who have cognitive dysfunction: protocol for a MOST study

INTRODUCTION

People who inject drugs (PWID) have remained a contributor to the consistent HIV incidence rates in the US for decades. Pre-exposure prophylaxis (PrEP) is a promising biomedical intervention for HIV prevention among individuals at risk for HIV infection, including PWID. However, PWID report the lowest rates of PrEP uptake and adherence among at-risk groups. Tailored HIV prevention interventions must include strategies that compensate for cognitive dysfunction among PWID.

METHODS AND ANALYSIS

Using the multiphase optimisation strategy, we will be conducting a 16-condition factorial experiment to investigate the effects of four different accommodation strategy components to compensate for cognitive dysfunction among 256 PWID on medication for opioid use disorder. This innovative approach will inform optimisation of a highly effective intervention to enhance PWID's ability to process and utilise HIV prevention content to improve PrEP adherence and HIV risk reduction in a drug treatment setting.

ETHICS AND DISSEMINATION

The institutional review board at the University of Connecticut approved this protocol (H22-0122) with an institutional reliance agreement with APT Foundation Inc. All participants are required to sign an informed consent form prior to engaging in any study protocols. The results of this study will be disseminated on national and international platforms through presentations at major conferences and journals.

TRIAL REGISTRATION NUMBER

NCT05669534.

A Novel Algorithm to Improve PrEP Adherence Monitoring Using Dried Blood Spots

Tenofovir diphosphate (TFVdp; an active metabolite of oral HIV pre-exposure prophylaxis (PrEP)) is measured in dried blood spots (DBS) to estimate adherence. However, TFVdp's long half-life in whole blood may lead to misclassification following a recent change in adherence. PrEP's other metabolite, emtricitabine triphosphate (FTCtp), has a shorter half-life in whole blood but adherence thresholds are undefined. We characterized DBS TFVdp and FTCtp concentrations across many dosing scenarios. Population pharmacokinetic models were fit to TFVdp and FTCtp DBS concentrations from a directly observed therapy study (NCT03218592). Concentrations were simulated for 90 days of daily dosing followed by 90 days of 1 to 7 doses/week and for event-driven PrEP (edPrEP) scenarios. Thresholds of 1,000 and 200 fmol/punch, for TFVdp and FTCtp, respectively, were reflective of taking 4 doses/week (a minimum target for effective PrEP in men). TFVdp was < 1,000 fmol/punch for 17 days after initiating daily PrEP and > 1,000 fmol/punch for 62 days after decreasing to 3 doses/week. Respectively, FTCtp was < 200 fmol/punch for 4 days and > 200 fmol/punch for 6 days. Accuracy of edPrEP adherence classification depended on duration between last sex act and DBS sampling for both measures with misclassification ranging from 9-100%. These data demonstrate adherence misclassification by DBS TFVdp for 2 months following a decline in adherence, elucidating the need for FTCtp to estimate recent adherence. We provide proof of principle that individualized interpretation is needed to support edPrEP adherence monitoring. Our collective approach facilitates clinicians' ability to interpret DBS results and administer patient-centric interventions.

Viral and Host Mediators of Non-Suppressible HIV-1 Viremia

Non-suppressible HIV-1 viremia (NSV) can occur in persons with HIV despite adherence to combination antiretroviral therapy (ART) and in the absence of significant drug resistance. Here, we show that plasma NSV sequences are comprised primarily of large clones without evidence of viral evolution over time. We defined proviruses that contribute to plasma viremia as "producer", and those that did not as "non-producer". Compared to ART-suppressed individuals, NSV participants had a significantly larger producer reservoir. Producer proviruses were enriched in chromosome 19 and in proximity to the activating H3K36me3 epigenetic mark. CD4+ cells from NSV participants demonstrated upregulation of anti-apoptotic genes and downregulation of pro-apoptotic and type I/II interferon-related pathways. Furthermore, NSV participants showed no elevation in HIV-specific CD8+ cell responses and producer proviruses were enriched for HLA escape mutations. We identified critical host and viral mediators of NSV that represent potential targets to disrupt HIV persistence and promote viral silencing.

Effectiveness and Safety of Bictegravir/Emtricitabine/Tenofovir Alafenamide in Patients With HIV-1 Infection and Ongoing Substance Use Disorder: The BASE Study

Background

People with human immunodeficiency virus (HIV) and substance use disorder (PWH/SUD) are at higher risk of nonadherence to antiretroviral therapy. Bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) exhibits high rates of efficacy with a favorable adverse event profile. The BASE study (NCT03998176) is a phase 4, single-arm study evaluating the effectiveness and safety of B/F/TAF among PWH/SUD.

Methods

Viremic (HIV RNA >1000 copies/mL) PWH/SUD initiated B/F/TAF once daily for 48 weeks (W). The primary endpoint was proportion of participants with HIV RNA <50 copies/mL at W24. Secondary endpoints were proportion of participants with HIV-1 RNA <50 copies/mL at W48, safety, B/F/TAF adherence (dried blood spot [DBS] concentrations of emtricitabine triphosphate and tenofovir diphosphate [TFV-DP]), substance use (NIDA-ASSIST), and quality of life (SF-12).

Results

Forty-three participants were enrolled; 95% reported methamphetamine use. Median age was 38 (range, 21-62) years; 21% were female, 81% White, 14% Black, and 16% Hispanic. Thirty-two (74%) and 21 (49%) participants had HIV RNA <50 copies/mL (intention-to-treat) at W24 and W48, respectively. Seven participants (16%) experienced confirmed virologic failure through W48; 1 developed emergent drug resistance (M184V). Fifteen participants (35%) experienced grade ≥3 adverse events. Five participants (12%) reported suicidal ideation; none resulted in discontinuation. Median DBS concentrations were representative of 5-6 doses/week (TFV-DP, 1603 fmol/punches). NIDA-ASSIST scores declined from baseline to W48 with methamphetamine use decreasing most (-7.9 points; -29%), and SF-12 physical/mental scores increased 1.2 and 7.6 points, respectively.

Conclusions

B/F/TAF among a high-risk population of PWH/SUD resulted in an initial 72% viral suppression rate at W24 before dropping to 49% at W48 as retention declined. One participant developed emergent drug resistance (M184V).

Randomized Controlled Trial of Automated Directly Observed Therapy for Measurement and Support of PrEP Adherence Among Young Men Who have Sex with Men

Measurement of adherence to oral pre-exposure prophylaxis (PrEP) in real-time has been challenging. We developed DOT Diary, a smartphone application that combines automated directly observed therapy with a PrEP adherence visualization toolkit, and tested its ability to measure PrEP adherence and to increase adherence among a diverse cohort of young men who have sex with men (MSM). We enrolled 100 MSM in San Francisco and Atlanta and randomly assigned them 2:1 to DOT Diary versus standard of care. Concordance between DOT Diary measurement and drug levels in dried blood spots was substantial, with 91.0% and 85.3% concordance between DOT Diary and emtricitabine-triphosphate and tenofovir-diphosphate, respectively. There was no significant difference in the proportion of participants with detectable PrEP drug levels at 24 weeks between study arms. These results suggest DOT Diary is substantially better than self-reported measures of adherence, but additional interventions are needed to improve PrEP adherence over time.

Clinic-Integrated Mobile Health Intervention ("JomPrEP" App) to Improve Uptake of HIV Testing and Pre-exposure Prophylaxis Among Men Who Have Sex With Men in Malaysia: Protocol for an Intervention Development and Multiphase Trial

BACKGROUND

Men who have sex with men (MSM) are disproportionately affected by the HIV epidemic in Malaysia and globally. Cross-cutting prevention strategies such as mobile health (mHealth), particularly smartphone apps, hold great promise for HIV prevention efforts among Malaysian MSM, especially when linked to HIV testing and pre-exposure prophylaxis (PrEP).

OBJECTIVE

This study aims to adapt an existing app to create and test a clinic-integrated app (JomPrEP), a virtual platform to deliver HIV testing and PrEP services for MSM in Malaysia.

METHODS

The JomPrEP project involves developing and testing an app-based platform for HIV prevention among Malaysian MSM and will be conducted in 2 phases. In phase I (development phase), we will adapt an existing mHealth app (HealthMindr) to create a new clinic-integrated app called "JomPrEP" to deliver holistic HIV prevention services (eg, HIV testing, PrEP, support services for mental health and substance use) among MSM in Malaysia. During phase II (testing phase), we will use a type I hybrid implementation science trial design to test the efficacy of JomPrEP while gathering information on implementation factors to guide future scale-up in real-world settings.

RESULTS

As of September 2022, we have completed phase I of the proposed study. Based on a series of formative work completed during phase I, we developed a fully functional, clinic-integrated JomPrEP app, which provides a virtual platform for MSM in Malaysia to facilitate their engagement in HIV prevention in a fast and convenient manner. Based on participant feedback provided during phase I, we are currently optimizing JomPrEP and the research protocols for a large-scale efficacy trial (phase II), which will commence in January 2023.

CONCLUSIONS

Scant HIV prevention resources coupled with entrenched stigma, discrimination, and criminalization of same-sex sexual behavior and substance use hamper access to HIV prevention services in Malaysia. If found efficacious, JomPrEP can be easily adapted for a range of health outcomes and health care delivery services for MSM, including adaptation to other low- and middle-income countries.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05325476; https://clinicaltrials.gov/ct2/show/NCT05325476.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/43318.

Nurse Practitioner-Led Integrated Rapid Access to HIV Prevention for People Who Inject Drugs (iRaPID): Protocol for a Pilot Randomized Controlled Trial

BACKGROUND

The ongoing volatile opioid epidemic remains a significant public health concern, alongside continued outbreaks of HIV and hepatitis C virus among people who inject drugs. The limited access to and scale-up of medications for opioid use disorder (MOUD) among people who inject drugs, coupled with multilevel barriers to pre-exposure prophylaxis (PrEP) uptake, makes it imperative to integrate evidence-based risk reduction and HIV prevention strategies in innovative ways. To address this need, we developed an integrated rapid access to HIV prevention program for people who inject drugs (iRaPID) that incorporates same-day PrEP and MOUD for this population.

OBJECTIVE

The primary objective of this pilot study is to assess the feasibility and acceptability of the program and evaluate its preliminary efficacy on PrEP and MOUD uptake for a future randomized controlled trial (RCT). We also aim to explore information on the implementation of the program in a real-world setting using a type I hybrid implementation trial design.

METHODS

Using a type I hybrid implementation trial design, we are pilot testing the nurse practitioner-led iRaPID program while exploring information on its implementation in a real-world setting. Specifically, we will assess the feasibility and acceptability of the iRaPID program and evaluate its preliminary efficacy on PrEP and MOUD uptake in a pilot RCT. The enrolled 50 people who inject drugs will be randomized (1:1) to either iRaPID or treatment as usual (TAU). Behavioral assessments will occur at baseline, and at 1, 3, and 6 months. Additionally, we will conduct a process evaluation of the delivery and implementation of the iRaPID program to collect information for future implementation.

RESULTS

Recruitment began in July 2021 and was completed in August 2022. Data collection is planned through February 2023. The Institutional Review Boards at Yale University and the University of Connecticut approved this study (2000028740).

CONCLUSIONS

This prospective pilot study will test a nurse practitioner-led, integrated HIV prevention program that incorporates same-day PrEP and MOUD for people who inject drugs. This low-threshold protocol delivers integrated prevention via one-stop shopping under the direction of nurse practitioners. iRaPID seeks to overcome barriers to delayed PrEP and MOUD initiation, which is crucial for people who inject drugs who have had minimal access to evidence-based prevention.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04531670; https://clinicaltrials.gov/ct2/show/NCT04531670.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/42585.

Brief Report: Transgender Women and Preexposure Prophylaxis Care: High Preexposure Prophylaxis Adherence in a Real-World Health Care Setting in New York City

BACKGROUND

Transgender women and trans feminine individuals (TGW/TFI) are a high priority population for the provision of HIV preexposure prophylaxis (PrEP) care within the United States, but there is limited research that focuses specifically on PrEP adherence within this population.

SETTING

Observational study of patients prescribed PrEP at a community-based health center.

METHODS

We enrolled 100 TGW/TFI PrEP patients at a community health center during clinic visits. Adherence data were collected at 3 time points, using self-report surveys, patient interviews, and urine assays measuring tenofovir. Data were summarized descriptively.

RESULTS

The sample was diverse in age, race/ethnicity, and socioeconomic characteristics. Participants demonstrated strong PrEP adherence; at least 80% of the sample reported 90% or greater adherence at each time point. Concordance between self-report and urine assay was high. Among patients who reported taking PrEP within the past 48 hours, 82%-92% had detectable urine tenofovir. However, many patients reported PrEP stop periods of 4 or more days (28%-39% per time point).

CONCLUSIONS

Our data highlight TGW/TFI's capacity to adhere to daily PrEP and sustain PrEP use over time. The concordance between patient self-report and urine TFV levels suggest that providers can trust patient reports of PrEP adherence behavior and support the use of adherence conversations in clinical settings, without the need for point of care biological monitoring. Findings also underscore the importance of continued attention to drivers of PrEP stops at the patient, clinic, and systems levels and the development of strategies that support sustained PrEP use.

Emtricitabine triphosphate in dried blood spots predicts future viremia in persons with HIV and identifies mismatch with self-reported adherence

OBJECTIVE

Emtricitabine triphosphate (FTC-TP) in dried blood spots (DBS), a measure of short-term antiretroviral therapy (ART) adherence, is associated with viral suppression in persons with HIV (PWH). However, its ability to predict future viremia remains unknown.

DESIGN

Prospective, observational cohort (up to three visits in 48 weeks).

METHODS

PWH receiving TDF/FTC-based ART had DBS and HIV viral load obtained at routine clinical visits. FTC-TP in DBS was dichotomized into quantifiable vs. below the limit of quantification (BLQ). The adjusted odds ratio (aOR) of future viremia (≥20 copies/ml at next study visit) was estimated according to FTC-TP at the current visit. To assess for possible interactions, additional models adjusted for tenofovir diphosphate (TFV-DP) in DBS and 3-day self-reported adherence.

RESULTS

Data from 433 PWH (677 paired DBS/HIV viral load samples) were analyzed. The aOR [95% confidence interval (CI)] for future viremia for BLQ vs. quantifiable FTC-TP was 3.4 (1.8--6.5; P = 0.0002). This diminished after adjusting for TFV-DP [aOR 1.9 (0.9--4.1); P = 0.090]. Among PWH reporting 100% 3-day adherence, the odds of future viremia were 6.0 times higher [(1.8--20.3); P = 0.001] when FTC-TP was BLQ vs. quantifiable. Among participants (n = 75) reporting less than 100% adherence, BLQ FTC-TP in DBS was not predictive of future viremia [aOR 1.3 (0.4--4.6); P = 0.96].

CONCLUSION

Nonquantifiable FTC-TP in DBS predicts future viremia and is particularly informative in PWH reporting perfect adherence. As point-of-care adherence measures become available, mismatches between objective and subjective measures, such as FTC-TP in DBS and self-report, could help clinicians identify individuals at an increased risk of future viremia.

Estimated pill intake with on-demand PrEP with oral TDF/FTC using TFV-DP concentration in dried blood spots in the ANRS IPERGAY trial

BACKGROUND

Tenofovir diphosphate (TFV-DP) concentration in dried blood spots (DBSs) is a reliable pharmacokinetics biomarker of adherence to tenofovir disoproxil fumarate (TDF). We aimed to use DBSs to estimate pill intake among participants using on-demand pre-exposure prophylaxis (PrEP) and to identify predictive factors associated with higher TFV-DP concentrations.

METHODS

DBSs were collected at the last study visit of the open-label phase of the ANRS IPERGAY study, assessing on-demand oral TDF/emtricitabine for PrEP among MSM and transgender female participants. We quantified TFV-DP in DBSs centrally. We assessed correlation between pill count and TFV-DP concentration by Spearman correlation and explored associations between participant demographics, sexual behaviour and PrEP use during sexual intercourse (SI) with TFV-DP concentrations by univariate and multivariate logistic regression models.

RESULTS

The median age of the 245 participants included in this study was 40 years, with a median body weight of 73 kg. Median (IQR) TFV-DP concentration reached 517 (128-868) fmol/punch, corresponding to an estimated intake of 8-12 tablets per month (2-3 doses per week). Only 39% of participants had a TFV-DP concentration above 700 fmol/punch. TFV-DP concentrations were moderately correlated with pill count (r: 0.59; P < 0.001). In multivariate analysis, only systematic use of PrEP during SI and more frequent episodes of SI in the past 4 weeks were significantly associated with higher TFV-DP levels [OR (95% CI): 11.30 (3.62-35.33) and 1.46 (1.19-1.79), respectively; P < 0.001].

CONCLUSIONS

Among participants using on-demand PrEP, estimated pill intake reached 8-12 tablets per month and was correlated with frequency and systematic use of PrEP for SI.

HIV, aging, and adherence: an update and future directions

PURPOSE OF REVIEW

To highlight recent data on antiretroviral adherence in older people living with HIV (PLWH), describe the most relevant pharmacokinetic antiretroviral studies, and identify critical research gaps in this population.

RECENT FINDINGS

Overall, studies have found that older PLWH are more likely to be adherent to antiretroviral therapy (ART). Although multiple methods to measure adherence are available (self-report, pharmacy refills, electronic device monitors, drug concentrations), there is currently no 'gold standard' adherence measure or sufficient evidence to suggest a preferred method in older patients. Recently, studies evaluating antiretroviral concentrations in hair and dried blood spots in older patients identified no major differences when compared with younger individuals. Similarly, although pharmacokinetic studies in older PLWH are scarce, most data reveal no significant pharmacokinetic differences in the aging population. Furthermore, no specific guidelines or treatment recommendations regarding ART dose modification or long-term toxicity in aging PLWH are available, mostly because of the exclusion of this population in clinical trials.

SUMMARY

How aging influences adherence and pharmacokinetics remains poorly understood. As the population of older PLWH increases, research focusing on adherence, toxicity, drug--drug interactions, and the influence of comorbidities is needed.

The Value of Assessing Self-Reported and Biological Indicators of Outcomes in Evaluating HIV Programs

PURPOSE OF REVIEW

In this manuscript, we present recent findings concerning concordance and discrepancy between biological measures and self-reports of these three outcomes of HIV programs: HIV status, adherence to antiretroviral medications (ARVs) and use of and adherence to pre-exposure prophylaxis medication (PrEP), and condom use/unprotected sex.

RECENT FINDINGS

Recent studies suggest that three successive rapid HIV tests (for those whose first test in positive) might be reasonably inexpensive and valid biological data to collect to combine with self-reports of HIV status, dried blood spots sufficiently affordable to combine with self-reports of adherence to ARVs and use of or adherence to PrEP, and that the discrepancy between self-reports of condom use and biomarkers of unprotected sex may be relatively small in high-income countries. Additional work on assessment of incorrect condom usage and breakage, standardized self-report measures of condom use, and more private data collection methodologies in low-income settings might reduce the recent observed discrepancies even further. Concordance between self-reports of HIV and biomarkers indicating HIV positive status has varied considerably, with much lower rates in low-income countries, where the stigma of HIV is still very high. Recommendation is for combining self-report data with the results of three successive rapid tests for those testing positive. For adherence, again agreement between self-reports and a variety of more objective and/or biological measures is only moderate. Dried blood spots (DBS) may be sufficiently inexpensive in low-resource settings that this may be the best biological method to combine with self-reports. In publications over the last 8 years, the discrepancy between self-reports of condom use and biomarkers for unprotected sex may be even lower than 20% after controlling for other features of the study, particularly in high-income countries. Our results suggest that more careful assessment of incorrect condom use and breakage as reasons other than intentional misreporting should be investigated more carefully and that more private data collection methods such as audio, computer-assisted self-interviewing (ACASI) might be employed more often in low-resource settings to reduce this discrepancy in those settings further. In addition, further analysis of the discrepancy between self-reports of condom use and biomarkers should be conducted of published studies using the correct calculation methods to be more certain of these findings.

"I wish to remain HIV negative": Pre-exposure prophylaxis adherence and persistence in transgender women and men who have sex with men in coastal Kenya

BACKGROUND

Transgender women (TGW) and men who have sex with men (MSM) in sub-Saharan Africa have high HIV acquisition risks and can benefit from daily pre-exposure prophylaxis (PrEP). We assessed PrEP adherence by measuring tenofovir-diphosphate (TFV-DP) levels and explore motives for PrEP persistence in TGW and MSM.

METHODS

Participants were enrolled in a one-year PrEP programme and made quarterly visits irrespective of whether they were still using PrEP. At their month 6 visit, participants provided a dried blood spot to test for TFV-DP levels; protective levels were defined as those compatible with ≥4 pills per week (700-1249 fmol/punch). Before TFV-DP levels were available, a sub-set of these participants were invited for an in-depth interview (IDI). Semi-structured IDI topic guides were used to explore motives to uptake, adhere to, and discontinue PrEP. IDI data were analyzed thematically.

RESULTS

Fifty-three participants (42 MSM and 11 TGW) were enrolled. At month 6, 11 (20.7%) participants (8 MSM and 3 TGW) were lost to follow up or stopped taking PrEP. Any TFV-DP was detected in 62.5% (5/8) of TGW vs. 14.7% of MSM (5/34, p = 0.01). Protective levels were detected in 37.5% of TGW (3/8), but not in any MSM. Nineteen IDI were conducted with 7 TGW and 9 MSM on PrEP, and 1 TGW and 2 MSM off PrEP. Unplanned or frequent risky sexual risk behaviour were the main motives for PrEP uptake. Among participants on PrEP, TGW had a more complete understanding of the benefits of PrEP. Inconsistent PrEP use was attributed to situational factors. Motives to discontinue PrEP included negative reactions from partners and stigmatizing healthcare services.

CONCLUSION

While MSM evinced greater adherence challenges in this PrEP programme, almost 40% of TGW were protected by PrEP. Given high HIV incidences in TGW these findings hold promise for TGW PrEP programming in the region.

Higher medication complexity in persons with HIV is associated with lower tenofovir diphosphate in dried blood spots

STUDY OBJECTIVE

To assess the association between tenofovir diphosphate (TFV-DP) in dried blood spots (DBS), a measure of cumulative tenofovir-based antiretroviral (ART) adherence, with medication regimen complexity in persons with human immunodeficiency virus (PWH).

DESIGN

Prospective clinical cohort (up to three visits over 48 weeks).

SETTING

Academic-based HIV clinic.

PATIENTS

PWH receiving tenofovir disoproxil fumarate (TDF)-based ART.

MEASUREMENTS

DBS for TFV-DP were collected at every study visit. Baseline patient-level medication regimen complexity index (pMRCI) scores were calculated and categorized into three sub-scores (disease-specific [ART], non-ART, and over-the-counter [OTC]). The pMRCI scores were evaluated to assess the association with TFV-DP in DBS <350 fmol/punch after adjusting for clinical covariates. pMRCI scores were also categorized to estimate the adjusted relative risk (aRR) of having a TFV-DP <350 fmol/punch between pMRCI quartiles.

MAIN RESULTS

Data from 525 participants (1,146 person-visits) were analyzed. Baseline median (interquartile range [IQR]) pMRCI scores for participants with TFV-DP in DBS <350 vs. ≥350 fmol/punch were 4 (3, 8) vs. 4 (2, 6) for ART, 27 (12, 31) vs. 12 (5, 22) for non-ART, and 0 (0, 1) vs. 0 (0, 2) for OTC, respectively. For the non-ART scores, the aRR for having a TFV-DP in DBS <350 fmol/punch was 6.4 (95% CI: 2.0, 20.6; P=0.002) when comparing participants in the highest pMRCI quartile with those in the lowest quartile.

CONCLUSIONS

Higher pMRCI for non-ART medications is associated with lower adherence as measured by TFV-DP in DBS. Future research should investigate whether reducing non-ART medication complexity improves ART adherence and exposure in PWH.

Approaches to Objectively Measure Antiretroviral Medication Adherence and Drive Adherence Interventions

PURPOSE OF REVIEW

Traditional methods to assess antiretroviral adherence, such as self-report, pill counts, and pharmacy refill data, may be inaccurate in determining actual pill-taking to both antiretroviral therapy (ART) or pre-exposure prophylaxis (PrEP). HIV viral loads serve as surrogates of adherence on ART, but loss of virologic control may occur well after decreases in adherence and viral loads are not relevant to PrEP.

RECENT FINDINGS

Pharmacologic measures of adherence, electronic adherence monitors, and ingestible electronic pills all serve as more objective metrics of adherence, surpassing self-report in predicting outcomes. Pharmacologic metrics can identify either recent adherence or cumulative adherence. Recent dosing measures include antiretroviral levels in plasma or urine, as well as emtricitabine-triphosphate in dried blood spots (DBS) for those on tenofovir-emtricitabine-based therapy. A urine tenofovir test has recently been developed into a point-of-care test for bedside adherence monitoring. Cumulative adherence metrics assess adherence over weeks to months and include measurement of tenofovir-diphosphate in peripheral blood mononuclear cells or DBS, as well as ART levels in hair. Electronic adherence monitors and ingestible electronic pills can track pill bottle openings or medication ingestion, respectively. New and objective approaches in adherence monitoring can be used to detect nonadherence prior to loss of prevention efficacy or virologic control with PrEP or ART, respectively.

Greater Levels of Self-Reported Adherence to Pre-Exposure Prophylaxis (PrEP) are Associated with Increased Condomless Sex Among Men Who Have Sex with Men

The effectiveness of pre-exposure prophylaxis (PrEP) against HIV acquisition depends on treatment adherence; however, within-person associations between levels of PrEP adherence and engagement in condomless sex have not been well studied. In the context of a demonstration project, 372 men who have sex with men received once-daily PrEP and completed six study visits over 48 weeks. Two-part growth mixture modeling was used to examine the longitudinal trajectory of condomless anal intercourse (CAI) and self-reports of PrEP adherence, controlling for relevant covariates. Over time, greater PrEP adherence was contemporaneously associated with both a higher likelihood of engaging in any CAI and with a greater number of CAI acts. Substance use was also associated with a higher likelihood of engaging in CAI. Contemporaneous associations between self-reported PrEP adherence and CAI suggest that adherence behaviors may be motivated by the desire to mitigate risk of HIV infection; however, exact directionality is unknown.

Couples-based approach to HIV prevention for transgender women and their partners: study protocol for a randomised controlled trial testing the efficacy of the 'It Takes Two' intervention

INTRODUCTION

HIV transmission and acquisition risk among transgender women is particularly high in the context of primary partnerships. This project extends a previous pilot couples-focused HIV intervention programme, which was shown to be feasible, acceptable and promising in reducing sexual risk behaviour among transgender women and their partners. This randomised controlled trial (RCT) tests the efficacy of this culturally sensitive HIV prevention programme for HIV-serodiscordant and HIV-negative seroconcordant transgender women and their partners.

METHODS AND ANALYSIS

To finalise the protocol for trial, we used qualitative methods to hone eligibility criteria, refine the intervention and control manuals, and name and brand the intervention ('It Takes Two'). The RCT investigates the effects of the It Takes Two intervention on Composite Risk for HIV (CR-HIV) among 100 couples. CR-HIV is a binary indicator of couple HIV risk using validated measures of sexual behaviour, pre-exposure prophylaxis use among HIV-negative participants and viral suppression among participants living with HIV. Using a two-arm RCT, we will examine intervention effects on CR-HIV at 12-month follow-up comparing transgender women and their partners randomised to the intervention versus control (HIV prevention information only).

ETHICS AND DISSEMINATION

This study has been reviewed and approved by the University of California, San Francisco (19-28624) and the University of Michigan (HUM00147690) Institutional Review Boards. Participants provide informed consent before taking part of the study activities. Results will be published in peer-reviewed journals and presented at scientific conferences. We will make our results available to the community of researchers and general public interested in transgender health to avoid unintentional duplication of research, as well as to others in the health and social services community, including LGBT community-based organisations, AIDS service organisations and other transgender-serving organisations. The full de-identified dataset and codebook will be shared at the University of Michigan Digital Repository.

TRIAL REGISTRATION NUMBER

NCT04067661.

Point-of-care and Near Real-time Testing for Antiretroviral Adherence Monitoring to HIV Treatment and Prevention

PURPOSE OF REVIEW

In this report, we review the need for point-of-care (POC) or near real-time testing for antiretrovirals, progress in the field, evidence for guiding implementation of these tests globally, and future directions in objective antiretroviral therapy (ART) or pre-exposure prophylaxis (PrEP) adherence monitoring.

RECENT FINDINGS

Two cornerstones to end the HIV/AIDS pandemic are ART, which provides individual clinical benefits and eliminates forward transmission, and PrEP, which prevents HIV acquisition with high effectiveness. Maximizing the individual and public health benefits of these powerful biomedical tools requires high and sustained antiretroviral adherence. Routine monitoring of medication adherence in individuals receiving ART and PrEP may be an important component in interpreting outcomes and supporting optimal adherence. Existing practices and subjective metrics for adherence monitoring are often inaccurate or unreliable and, therefore, are generally ineffective for improving adherence. Laboratory measures of antiretroviral concentrations using liquid chromatography tandem mass spectrometry have been utilized in research settings to assess medication adherence, although these are too costly and resource-intensive for routine use. Newer, less costly technologies such as antibody-based methods can provide objective drug-level measurement and may allow for POC or near-patient adherence monitoring in clinical settings. When coupled with timely and targeted counseling, POC drug-level measures can support adherence clinic-based interventions to ART or PrEP in near real time.

PrEP uptake and adherence in relation to HIV-1 incidence among Kenyan men who have sex with men

BACKGROUND

Data on HIV-1 incidence following programmatic pre-exposure prophylaxis (PrEP) uptake by men who have sex with men (MSM) are limited in sub-Saharan Africa.

METHODS

Since June 2017, MSM participating in an ongoing cohort study in Kenya were offered daily PrEP, assessed for PrEP uptake and adherence, and evaluated for HIV-1 acquisition monthly. We determined tenofovir-diphosphate (TFV-DP) concentrations in dried blood spots 6-12 months after PrEP initiation, and tenofovir (TFV) concentrations and genotypic drug resistance in plasma samples when HIV-1 infection occurred. We assessed HIV-1 incidence by reported PrEP use.

FINDINGS

Of 172 MSM, 170 (98·8%) were eligible for PrEP, 140 (82·4%) started it, and 64 (57·7%) reported PrEP use at end of study. Of nine MSM who acquired HIV-1 [incidence rate: 3·9 (95% confidence interval (CI), 2·0-7·4) per 100 person-years (PY)], five reported PrEP use at the time of HIV-1 acquisition [incidence rate: 3·6 (95% CI, 1·5-8·6) per 100 PY)] and four had stopped or had never started PrEP [incidence rate: 4·3 (95% CI, 1·6-11·3) per 100 PY]. Among 76 MSM who reported PrEP use, 11 (14·5%) had protective TFV-DP concentrations of ≥700 fmol/punch (≥4 tablets a week). Among the five MSM who acquired HIV-1 while reporting PrEP use, only one had detectable but low TFV concentrations in plasma and none had genotypic HIV-1 resistance.

INTERPRETATION

HIV-1 incidence among MSM with access to programmatic PrEP was high and did not differ by reported PrEP use. Only one in seven MSM taking PrEP had protective tenofovir concentrations and four out of five MSM who acquired HIV-1 while reporting PrEP use had not taken it. Strengthened PrEP adherence support is required among MSM in Kenya.

FUNDING

This work was supported by the International AIDS Vaccine Initiative (IAVI).

PrEP Nonadherence, White Coat Dosing, and HIV Risk Among a Cohort of MSM

Among a cohort of men who have sex with men in a pre-exposure prophylaxis (PrEP) adherence trial, syphilis requiring treatment was associated with white coat dosing (increased PrEP adherence immediately preceding study visits) when compared with participants with optimal drug concentrations. The findings highlight the need for identifying and reducing barriers to PrEP adherence.

Emtricitabine triphosphate in dried blood spots is a predictor of viral suppression in HIV infection and reflects short-term adherence to antiretroviral therapy

BACKGROUND

Emtricitabine triphosphate (FTC-TP), the phosphorylated anabolite of emtricitabine, can be quantified in dried blood spots (DBS). We evaluated FTC-TP in DBS as a predictor of viral suppression and evaluated self-reported adherence as a predictor of FTC-TP.

METHODS

Persons living with HIV (PLWH) on an FTC-containing regimen were prospectively recruited. A DBS and HIV viral load were obtained during routine clinical visits. Self-reported adherence for 3 days, 30 days and 3 months was captured. Generalized estimating equations were used to estimate the adjusted odds ratio (aOR) of viral suppression for quantifiable FTC-TP versus below the limit of quantification (BLQ). The utility of self-reported adherence to predict quantifiable FTC-TP was assessed by calculating the area under receiver operating characteristic (ROC) curve.

RESULTS

One thousand one hundred and fifty-four person-visits from 514 participants who had DBS assayed for FTC-TP were included in the analysis. After adjusting for age, gender, race, BMI, ART class, ART duration, estimated glomerular filtration rate and CD4+ T cell count, the aOR (95% CI) for viral suppression for quantifiable FTC-TP versus BLQ was 7.2 (4.3-12.0; P < 0.0001). After further adjusting for tenofovir diphosphate, the aOR was 2.1 (1.2-4.0; P < 0.015). The area under the ROC curve for 3 day self-reported adherence was 0.82 (95% CI 0.75-0.88) compared with 0.70 (95% CI 0.62-0.77, P = 0.004) and 0.79 (95% CI 0.71-0.86, P = 0.32) for 3 month and 30 day self-reported adherence, respectively.

CONCLUSIONS

In PLWH, FTC-TP from DBS is a strong predictor of viral suppression, even after adjusting for tenofovir diphosphate, and was best predicted by 3 day self-reported adherence.

Intracellular Tenofovir-Diphosphate and Emtricitabine-Triphosphate in Dried Blood Spots Following Tenofovir Alafenamide: The TAF-DBS Study

BACKGROUND

Tenofovir alafenamide (TAF), in combination with FTC, was recently approved for PrEP in the United States. The objective of this study was to assess the relationship between tenofovir-diphosphate (TFV-DP) and emtricitabine-triphosphate (FTC-TP) in dried blood spots (DBS) with adherence to TAF/FTC.

METHODS

TAF-DBS was a randomized, crossover clinical study of TFV-DP in DBS, following directly observed dosing of 33%, 67%, or 100% of daily TAF (25 mg)/FTC (200 mg). Healthy volunteers were randomized to 2 different, 12-week dosing regimens, separated by a 12-week washout. DBS were collected weekly. TFV-DP and FTC-TP were extracted from two 7-mm punches and assayed with LC-MS/MS.

RESULTS

Thirty-seven participants (17 female, 7 African American, and 6 Hispanic) were included. TFV-DP exhibited a mean half-life of 20.8 days (95% confidence interval: 19.3 to 21.3). The slope for TFV-DP versus dosing arm was 1.14 (90% confidence interval: 1.07 to 1.21). The mean (SD) TFV-DP after 12 weeks was 657 (186), 1451 (501), and 2381 (601) fmol/2 7-mm punches for the 33%, 67%, and 100% arms. The following adherence interpretations are proposed: <450 fmol/punches, <2 doses/wk; 450-949 fmol/punches, 2-3 doses/wk; 950-1799 fmol/punches, 4-6 doses/wk; and ≥1800 fmol/punches, 7 doses/wk. FTC-TP was quantifiable for 1 week after drug cessation in 50%, 92%, and 100% of participants in the 33%, 67%, and 100% arms, respectively.

CONCLUSION

TFV-DP in DBS after TAF/FTC exhibited a long half-life and was linearly associated with dosing, similar to its predecessor tenofovir disoproxil fumarate. FTC-TP was quantifiable for up to 1 week after drug cessation. Together, these moieties provide complementary measures of cumulative adherence and recent dosing for TAF/FTC.

Short Communication: Cascade of Antiretroviral Therapy Adherence in Virologically Suppressed Persons Living with HIV

Variable adherence to antiretroviral therapy (ART) can maintain HIV viral suppression, but our understanding of the ART adherence continuum remains limited. In a clinical cohort of adult persons living with HIV treated with a tenofovir (TFV) disoproxil fumarate/emtricitabine (TDF/FTC)-based regimen, data on 3-month self-reported adherence and dried blood spots (DBS) for TFV diphosphate (TFV-DP) and FTC triphosphate (FTC-TP) were collected. Among 521 participants in whom DBS were available upon enrollment, 333 were virologically suppressed (<20 copies/mL). Only 145 (44%) of them reported 100% 3-month adherence, and 69 (21%) had drug concentrations in the highest adherence categories (TFV-DP ≥1,850 fmol/punch and quantifiable FTC-TP). These findings demonstrate a wide range of ART adherence and drug exposure associated with viral suppression, indicating that modern regimens are pharmacologically forgiving. Additional research is needed to understand the biologic effects of variable adherence and drug exposure beyond plasma virologic suppression.

Antenatal Intracellular Concentrations of Tenofovir Diphosphate and Emtricitabine Triphosphate and Associations Between Tenofovir Diphosphate and Severe Adverse Pregnancy Outcomes: IMPAACT-PROMISE (1077BF) Trial

BACKGROUND

In the Promoting Maternal and Infant Survival Everywhere (PROMISE) trial, tenofovir disoproxil fumarate (TDF) use was associated with moderate or severe adverse pregnancy/neonatal outcomes. This study characterized tenofovir diphosphate (TFV-DP) and emtricitabine triphosphate (FTC-TP) concentrations in dried blood spots (DBS) and assessed association between severe adverse pregnancy/neonatal outcomes and TFV-DP concentration.

METHODS

Retrospective case-control study of PROMISE trial arm-C women randomized to receive TDF, FTC, and ritonavir-boosted lopinavir (LPV/r), who took at least 1 dose of TDF + FTC and had week-4 postrandomization DBS drawn before delivery. Cases, defined as severe adverse pregnancy/neonatal outcomes (very preterm delivery before 34 weeks of gestation, stillbirth ≥20 weeks of gestation, or infant death before 14 days-of-age), were matched to controls (1:2 ratio) by site and gestational age at entry. Week 4 and week 8 DBS samples were assayed for TFV-DP and FTC-TP by liquid chromatography and tandem mass spectrometry. Associations were tested using Wilcoxon rank test and conditional logistic regression.

RESULTS

Of 447 PROMISE arm-C women, 33 met case definitions, and overall, 22 cases and 44 controls were analyzed. Median (interquartile range) concentrations of TFV-DP at weeks 4 and 8 were 706 (375-1023) fmol/punch and 806 (414-1265) fmol/punch, respectively. Odds ratio (95% confidence interval) for severe adverse pregnancy/neonatal outcome with natural log of TFV-DP concentrations as the predictor were 1.27 (0.74 to 2.18) and 1.74 (0.66 to 4.60) at weeks 4 and 8, respectively. Median (interquartile range) concentrations of FTC-TP at weeks 4 and 8 were 0.27 (0.05-0.36) pmol/punch and 0.29 (0.05-0.40) pmol/punch, respectively.

CONCLUSIONS

TFV-DP concentrations in DBS appeared not to be associated with severe adverse pregnancy/neonatal outcomes, although sample size was limited.

Antiretroviral Concentration in Hair as a Measure for Antiretroviral Medication Adherence: A Systematic Review of Global Literature

This review aims to validate hair antiretroviral concentration (HAC) as a measure for antiretroviral medication adherence. This review included 31 studies that analyzed a total of 11 ARV drugs in four different drug classes. The associations between HAC and non-pharmacokinetic measures were generally lower than the association between HAC and other pharmacokinetic measures: the correlation coefficients (r) ranged from - 0.20 to 0.38 for self-report or pill counts and 0.20 to 0.85 for electronic drug monitoring; HAC and other pharmacokinetic measures were positively correlated with the correlation coefficients (r) ranging from 0.20 to 0.72, 0.34 to 0.86, 0.50 to 0.85 for antiretroviral concentration in plasma, peripheral blood mononuclear cells, and dried blood spots, respectively. HAC was one of the strongest independent predictors of virologic responses. HAC of tenofovir was significantly associated with renal toxicity in large sample studies. This review suggests that HAC is a valid biomarker of antiretroviral medication adherence.

Trajectories and Predictors of Longitudinal Preexposure Prophylaxis Adherence Among Men Who Have Sex With Men

Background

Adherence is necessary for efficacy of preexposure prophylaxis (PrEP), and text-messaging methods are promising tools for both adherence assessment and support. Although PrEP adherence is variable, little research has examined patterns of variability or factors associated with longitudinal use.

Methods

In the context of a randomized controlled trial of text-messaging versus standard of care for PrEP adherence, 181 men who have sex with men received once-daily tenofovir disoproxil fumarate/emtricitabine and daily adherence texts for 48 weeks. Growth mixture modeling (GMM) was used to identify subgroups of individuals with similar trajectories of text-reported adherence. Between-group differences in pharmacologic measures of adherence (ie, tenofovir diphosphate and emtricitabine triphosphate levels), as well as predictors and study-end attitudes associated with group membership, were examined.

Results

GMM identified 4 trajectories of text-reported adherence. Classes with higher text-reported adherence had higher drug concentrations. Younger age and minority race were associated with lower adherence, and individuals in classes with lower adherence had greater baseline levels of depression, substance use concerns, and sexual risk. Differences in study satisfaction were also associated with adherence.

Conclusions

This study supports the use of text-reported PrEP adherence. Identifying factors associated with less-than-optimal adherence may aid clinicians in anticipating at-risk patients requiring augmented intervention.

Clinical trials registration

NCT01761643.

Drug resistance and optimizing dolutegravir regimens for adolescents and young adults failing antiretroviral therapy

OBJECTIVES

The integrase strand inhibitor dolutegravir (DTG) combined with tenofovir and lamivudine (TLD) is a single tablet regimen recommended for 1st, 2nd and 3rd-line public health antiretroviral therapy (ART). We determined drug resistance mutations (DRMs) and evaluated the predictive efficacy of a TLD containing regimen for viremic adolescents and young adults in Harare, Zimbabwe.

METHODS

We sequenced plasma viral RNA from HIV-1-infected adolescents and young adults on 1st and 2nd-line ART with confirmed virologic failure (viral load >1000 copies/ml) and calculated total genotypic susceptibility scores to current 2nd, 3rd line and DTG regimens.

RESULTS

A total of 160 participants were genotyped; 112 (70%) on 1st line and 48 (30%) on 2nd line, median (interquartile range) age 18 (15-19) and duration of ART (interquartile range) was 6 (4-8) years. Major DRMs were present in 94 and 67% of 1st and 2nd-line failures, respectively (P < 0.001). Dual class resistance to nucleotide reverse transcriptase inhibitors and nonnucleotide reverse transcriptase inhibitors was detected in 96 (60%) of 1st-line failures; protease inhibitor DRMs were detected in a minority (10%) of 2nd-line failures. A total genotypic susceptibility score of 2 or less may risk protease inhibitor or DTG monotherapy in 11 and 42% of 1st-line failures switching to 2nd-line protease inhibitor and TLD respectively.

CONCLUSION

Among adolescents and young adults, current protease inhibitor-based 2nd-line therapies are poorly tolerated, more expensive and adherence is poor. In 1st-line failure, implementation of TLD for many adolescents and young adults on long-term ART may require additional active drug(s). Drug resistance surveillance and susceptibility scores may inform strategies for the implementation of TLD.

HIV-1 self-testing to improve the efficiency of pre-exposure prophylaxis delivery: a randomized trial in Kenya

Background

The introduction of pre-exposure prophylaxis (PrEP) for human immunodeficiency virus-1 (HIV-1) prevention in Africa presents new challenges for health systems that are already overburdened because PrEP delivery requires frequent clinic visits (generally every 3 months) for HIV-1 testing and PrEP refills. HIV-1 self-testing (HIVST) has the potential to improve the efficiency of PrEP delivery by decreasing the number of clinic visits. Here, we describe the rationale and design of a randomized, noninferiority trial designed to test the effectiveness and safety of using HIVST to support PrEP delivery in Kenya.

Methods

The JiPime-JiPrEP (Kiswahili for ‘Test Yourself, PrEP Yourself’) study is a three-arm randomized trial taking place in Thika, Kenya. Participants (n = 495) are eligible for enrollment if they are at least 18 years old, HIV-1 seronegative, and have been taking PrEP for 1 month. Three distinct participant types will be enrolled: men (n = 165) and women (n = 165) who are in mutually disclosed HIV-1 serodiscordant relationships, and women (n = 165) who are at HIV-1 risk and not in a known serodiscordant relationship. Participants in each of these subpopulations will be 1:1:1 randomized to: 1) the standard of care, with quarterly clinic visits; 2) oral HIVST, with biannual clinic visits plus oral HIVSTs to use at the quarters between those visits; or 3) blood-based HIVST, with biannual clinic visits plus blood-based HIVSTs. All participants will complete quantitative surveys and provide blood samples for the objective measurement of PrEP adherence at baseline, 6 months, and 12 months. The primary outcomes are PrEP adherence, PrEP continuation, and HIV-1 testing, measured at 6 months and secondarily at 12 months.

Discussion

The findings from this trial can help to understand how HIVST—a new HIV-1 testing technology—can support health systems in sub-Saharan Africa. Additionally, the findings can inform policy aimed at improving the efficiency of PrEP implementation and scale-up in Kenya.

Trial registration

ClinicalTrials.gov, NCT03593629. Retrospectively registered on 20 July 2018.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3521-2) contains supplementary material, which is available to authorized users.

Rationale and design of an integrated bio-behavioral approach to improve adherence to pre-exposure prophylaxis and HIV risk reduction among opioid-dependent people who use drugs: The CHRP-BB study

BACKGROUND

Few primary HIV prevention strategies have successfully integrated both behavioral and biomedical components, with modest HIV risk reduction outcomes among opioid-dependent people who use drugs (PWUD). In response to this unmet need, we developed a brief, bio-behavioral intervention to simultaneously promote PrEP adherence and reduce HIV risk among opioid-dependent PWUD.

METHODS

Using a Hybrid Type I implementation science design, we will examine the efficacy of the integrated bio-behavioral, Community-friendly Health Recovery Program (CHRP-BB) compared to a time-and-attention matched control condition among HIV-negative, opioid-dependent PWUD who are prescribed PrEP and enrolled in a methadone maintenance program (MMP) using a randomized controlled trial (RCT). Participants are assessed at baseline, immediately post-intervention (8 weeks) and follow-ups at weeks 20, 32, and 44 post-intervention. The primary outcome is biomedical (PrEP adherence), with secondary outcomes including behavioral (self-reported drug- and sex-related HIV risk behaviors), ongoing drug use (confirmed with urine drug testing), and related domains of the theoretical information-motivation-behavioral skills (IMB) model of behavior change related to PrEP adherence and HIV-transmission-risk reduction. Additionally, we will conduct a process evaluation of delivery/implementation of the intervention to collect valuable information to be used in future implementation.

CONCLUSIONS

This study will be among the first prospective trial to test an integrated bio-behavioral intervention to improve adherence to PrEP and HIV risk reduction among opioid-dependent PWUD.

Patient and clinician perspectives on optimizing graphical displays of longitudinal medication adherence data

OBJECTIVE

New pharmacological measures assessing medication adherence, including longitudinal drug levels in hair, are emerging. Little is known, however, about how best to present results from such measures to patients and clinicians in comprehensive, easy-to-understand, acceptable formats. We, therefore, developed three graphical display prototypes of hypothetical daily drug concentrations measured in hair, and assessed their acceptability among participants.

METHODS

We interviewed 30 HIV-positive patients and 29 clinicians to examine perceived acceptability for each graphical display prototype.

RESULTS

Patients and clinicians generally found the prototypes acceptable for facilitating understanding of patient adherence; however, areas for optimization were identified. For patients with lower health literacy, prototypes did not provide sufficient understanding of the link between medication-taking and drug concentrations in hair. These patients also preferred pictographs over bar or line graphs. Clinicians largely preferred daily drug concentration data in bar graphs with information included about the measure's accuracy. Participants questioned the utility of showing drug concentrations above a therapeutic range, though they found color-coding results acceptable.

CONCLUSIONS

Assessing prototype versions of graphical displays of hypothetical longitudinal adherence data indicated ways to optimize their acceptability.

PRACTICE IMPLICATIONS

Acceptable prototype-tested graphical displays of longitudinal patient-specific drug concentrations may enhance adherence monitoring in clinical settings.

Brief Report: Short-Term Adherence Marker to PrEP Predicts Future Nonretention in a Large PrEP Demo Project: Implications for Point-of-Care Adherence Testing

BACKGROUND

Objective adherence metrics for tenofovir (TFV) disoproxil fumarate/emtricitabine (FTC)-based pre-exposure prophylaxis (PrEP) were critical for interpretation of efficacy in PrEP clinical trials, and there is increasing interest in using drug levels to tailor interventions for reengagement and adherence. Point-of-care immunoassays for TFV, which examine short-term adherence, are in development. However, the ability of poor short-term and long-term adherence to predict future PrEP nonretention is unknown.

SETTING

Secondary data analysis of a large, prospective multi-site U.S. PrEP demonstration project.

METHODS

An adjusted Cox-proportional hazards model examined the relationship of dried blood spot (DBS) levels of FTC-triphosphate (FTC-TP) or TFV-diphosphate (TFV-DP), measures of short-term and long-term PrEP adherence, respectively, with future study nonretention.

RESULTS

Overall, 294 individuals (median age 33 years) contributed drug levels within the U.S. PrEP demonstration project. By the end of study, 27% were lost to follow-up, 25% had at least one undetectable FTC-TP level indicating poor short-term adherence, and 29% had a drug level indicating suboptimal long-term adherence (TFV-DP <700 fmol/punch). The strongest factor associated with future study nonretention using a binary drug-level cut-off was an undetectable DBS FTC-TP level (adjusted hazard ratio 6.3; 95% confidence interval 3.8 to 10.2). The suboptimal long-term adherence based on low DBS TFV-DP levels was also associated with nonretention (adjusted hazard ratio 4.3; 95% confidence interval: 2.4 to 7.6).

CONCLUSIONS

Both short- and long-term metrics of PrEP adherence are strongly associated with future loss to follow-up in a U.S. demonstration project study. Short-term metrics of adherence, once available at the point-of-care, could be used to direct real-time tailored retention and adherence interventions.

Adherence Measurements in HIV: New Advancements in Pharmacologic Methods and Real-Time Monitoring

PURPOSE OF REVIEW

In this review, we present new developments in antiretroviral adherence, focusing on pharmacological measures and real-time adherence monitoring. In addition, new strategies on how to incorporate these new measures into research and clinical care are proposed.

RECENT FINDINGS

Antiretroviral drug concentrations in hair and dried blood spots are two novel pharmacological measures of cumulative drug adherence and exposure that have been recently evaluated in HIV treatment and pre-exposure prophylaxis. Real-time adherence monitoring using electronic devices has also proven highly informative, feasible, and well accepted, offering the possibility for an immediate intervention when non-adherence is detected. Both approaches offer considerable advantages over traditional adherence measures in predicting efficacy. New methods to objectively monitor adherence in real-time and over long time periods have been developed. Further research is required to better understand how these measures can optimize adherence and, ultimately, improve clinical outcomes in HIV treatment and prevention.

Tenofovir-Diphosphate as a Marker of HIV Pre-exposure Prophylaxis Use Among East African Men and Women

Background: Controlled pharmacokinetic (PK) studies in United States populations have defined categories of tenofovir-diphosphate (TFV-DP) in dried blood spots (DBS) for various pre-exposure prophylaxis (PrEP) adherence targets. It is unknown how these categories perform in other populations. Therefore, we evaluated the sensitivity and specificity of these PK-derived categories compared to daily medication electronic adherence monitoring (MEMS) data among East African men and women using daily PrEP.

Methods: Participants were enrolled as members of HIV serodiscordant couples as part of an open-label PrEP study in Kenya and Uganda. Blood samples were taken at quarterly visits and stored as DBS, which were analyzed for TFV-DP concentrations.

Results: Among 150 samples from 103 participants, MEMs data indicated that 87 (58%) took ≥4 doses and 62 (41%) took ≥6 per week consistently over the 4 weeks prior to sample collection. Sensitivities of DBS TFV-DP levels were 62% for the ≥4 doses/week category (≥700 fmol/punch TFV-DP) and 44% for the ≥6 doses/week category (≥1050 fmol/punch TFV-DP); specificities were 86 and 94%, respectively. There were no statistically significant differences in these sensitivities and specificities by gender.

Conclusion: In this sample of East African PrEP users, categories of TFV-DP concentrations developed from directly observed PrEP use among United States populations had high specificity but lower than expected sensitivity. Sensitivity was lowest when MEMS data indicated high adherence (i.e., ≥6 doses/week). PrEP studies and implementation programs should carefully consider the sensitivity and specificity of the TFV-DP levels used for adherence feedback.