Pilot evaluation of an enzymatic assay for rapid measurement of antiretroviral drug concentrations.

OBJECTIVE: Maintaining adequate drug adherence is crucial to ensure the HIV prevention benefits of pre-exposure prophylaxis (PrEP). We developed an enzymatic assay for rapidly measuring tenofovir-diphosphate (TFV-DP) concentrations-a metabolite that indicates long-term PrEP adherence. SETTING: The study was conducted at the Madison HIV Clinic at Harborview Medical Center in Seattle. METHODS: We enrolled adults receiving standard oral PrEP, and individuals not receiving any antiretrovirals. We measured TFV-DP concentrations in diluted whole blood using our novel REverSe TRanscrIptase Chain Termination (RESTRICT) assay, based on inhibition of HIV reverse transcriptase (RT) enzyme. Blood samples were diluted in water, DNA templates, nucleotides, RT, and intercalating dye added, and results measured with a fluorescence reader-stronger fluorescence indicated higher RT activity. We compared RESTRICT assay results to TFV-DP concentrations from matched dried blood spot samples measured by liquid chromatography tandem mass spectrometry (LC-MS/MS) using ≥ 700 fmol/punch TFV-DP as a threshold for adequate adherence (≥ 4 doses/week). RESULTS: Among 18 adults enrolled, 4 of 7 participants receiving PrEP had TFV-DP levels ≥ 700 fmol/punch by LC-MS/MS. RESTRICT fluorescence correlated with LC-MS/MS measurements (r = - 0.845, p < 0.0001). Median fluorescence was 93.3 (95% confidence interval [CI] 90.9 to 114) for samples < 700 fmol/punch and 54.4 (CI 38.0 to 72.0) for samples ≥ 700 fmol/punch. When calibrated to an a priori defined threshold of 82.7, RESTRICT distinguished both groups with 100% sensitivity and 92.9% specificity. CONCLUSIONS: This novel enzymatic assay for measuring HIV reverse transcriptase activity may be suitable for distinguishing TFV-DP concentrations in blood that correspond to protective PrEP adherence.

Provider experiences with three- and six-month antiretroviral therapy dispensing for stable clients in Zambia.

Multi-month dispensing of antiretroviral therapy (ART) has been taken to scale in many settings in sub-Saharan Africa with the benefits of improved client satisfaction and decreased client costs. Six-month ART dispensing may further increase these benefits; however, data are lacking. Within a cluster-randomized trial of three- versus six-month dispensing in Malawi and Zambia, we performed a sub-study to explore Zambian provider experiences with multi-month dispensing. We conducted 18 in-depth interviews with clinical officers and nurses dispensing ART as part of INTERVAL in Zambia. Interview questions focused on provider perceptions of client acceptability, views on client sharing and selling of ART, and perceptions on provider workload and clinic efficiency, with a focus on differences between three- and six-month dispensing. Interviews were analyzed using inductive thematic analysis to identify key themes and patterns within the data. Providers perceived significant benefits of multi-month dispensing, with advantages of six-month over three-month dispensing related to a reduced burden on clients, and for reductions in their own workload and clinic congestion. Among nearly all providers, the six-month dispensing strategy was perceived as ideal. Further research is needed to quantify clinical outcomes of six-month dispensing and feasibility of scaling-up this intervention in resource-limited settings.Clinical Trial Number: NCT03101592.

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.

Perspectives on the utility and interest in a point-of-care urine tenofovir test for adherence to HIV pre-exposure prophylaxis and antiretroviral therapy: an exploratory qualitative assessment among U.S. clients and providers.

BACKGROUND: Real-time, objective measures of adherence to antiretroviral therapy (ART) and pre-exposure prophylaxis (PrEP) are needed to better assess adherence levels and to expedite clinical response for those with suboptimal adherence. Point-of-care tenofovir (POC-TFV) testing has been proposed as a solution to facilitate real-time antiretroviral adherence monitoring, but little is known about how health care providers, people living with HIV (PLWH) receiving ART, and people receiving PrEP will perceive POC-TFV testing. METHODS: We conducted an exploratory qualitative study to assess perspectives on the utility and interest in POC-TFV testing from potential end users. We conducted three focus group discussions (FGDs) among 17 PLWH receiving ART and four individuals receiving PrEP, as well as eight in-depth interviews (IDIs) with health care providers in the Seattle area and presented participants with a hypothetical urine-based POC-TFV test. FGDs and IDIs were audio recorded, transcribed, coded, and analyzed to describe emerging themes. RESULTS: Overall, study participants demonstrated divergent opinions about the POC-TFV test. Among study participants, PLWH were most ambivalent about POC-TFV testing, first demonstrating reluctance to TFV-level monitoring and shifting positions during the FGDs. However, all PLWH participants were receptive to POC-TFV testing if requested by their provider. PrEP participants were generally supportive of POC-TFV testing for routine adherence monitoring and emphasized potential value in self-administered testing. Providers' perceptions were equally divided - half suggested POC-TFV testing would be valuable, particularly for people receiving PrEP, while half indicated the test would have little benefit for most individuals receiving ART or PrEP in the U.S. All providers agreed that POC-TFV test results could be beneficial for assessing discrepancies in viral load results and self-reported adherence among PLWH. The study also revealed that a low-cost, non-urine-based POC-TFV test with a long-term limit of detection would be preferred over the hypothetical urine-based test. CONCLUSIONS: Our findings indicate POC-TFV testing may be beneficial for routine, clinic-based adherence monitoring, particularly for individuals receiving PrEP or for PLWH with persistent viremia or following recent ART initiation. These findings should also be used to formulate a target product profile for a POC-TFV test and to guide further developments in tools for objective antiretroviral adherence monitoring.

Effect of 6-Month HIV Preexposure Prophylaxis Dispensing With Interim Self-testing on Preexposure Prophylaxis Continuation at 12 Months: A Randomized Noninferiority Trial.

Importance: Daily oral HIV preexposure prophylaxis (PrEP) delivery requires quarterly clinic visits for HIV testing and drug refilling that are costly to health systems and clients. Objective: To evaluate whether 6-month PrEP dispensing supported with interim HIV self-testing (HIVST) results in noninferior PrEP continuation outcomes at 12 months compared with standard quarterly clinic visits. Design, Setting, and Participants: This randomized noninferiority trial was conducted from May 2018 to May 2021 with 12 months of follow-up among PrEP clients aged 18 years or older who were returning for their first refill at a research clinic in Kiambu County, Kenya. Intervention: Participants were randomized 2:1 to (1) 6-month PrEP dispensing with semiannual clinic visits and interim HIVST at 3 months or (2) standard-of-care (SOC) PrEP delivery with 3-month dispensing, quarterly clinic visits, and clinic-based HIV testing. Main Outcomes and Measures: Prespecified 12-month outcomes included recent HIV testing (any in past 6 months), PrEP refilling, and PrEP adherence (detectable tenofovir-diphosphate concentrations in dried blood spots). Binomial regression models were used to estimate risk differences (RDs), and a 1-sided 95% CI lower bound (LB) of -10% or greater was interpreted as noninferior. Results: A total of 495 participants were enrolled, with 329 enrolled in the intervention group and 166 enrolled in the SOC group; 330 (66.7%) were women, 295 (59.6%) were in serodifferent relationships, and the median (IQR) age was 33 (27-40) years. At 12 months, 241 individuals in the intervention group (73.3%) and 120 in the SOC group (72.3%) returned to clinic. In the intervention group, recent HIV testing was noninferior (230 individuals [69.9%]) compared with the SOC group (116 [69.9%]; RD, -0.33%, 95% CI LB, -7.44%). PrEP refilling in the intervention group (196 [59.6%]) was inconclusive compared with the SOC group (104 [62.7%]; RD, -3.25%; 95% CI LB, -10.84%), and PrEP adherence was noninferior in the intervention group (151 [45.9%]) compared with the SOC group (70 [42.2%]; RD, 4.96%; 95% CI LB, -2.46%). No HIV seroconversions were observed over the follow-up period. Conclusions and Relevance: In this analysis of secondary trial end points at 1 year, semiannual PrEP dispensing with interim HIVST resulted in noninferior recent HIV testing and PrEP adherence compared with SOC quarterly PrEP dispensing. This novel model has the potential to optimize PrEP delivery. Trial Registration: ClinicalTrials.gov Identifier: NCT03593629.

Efficiency of 6-month PrEP dispensing with HIV self-testing in Kenya: an open-label, randomised, non-inferiority, implementation trial.

BACKGROUND: Oral pre-exposure prophylaxis (PrEP) for HIV prevention is highly effective and is being implemented at scale at health clinics throughout sub-Saharan Africa. However, barriers to clinic-based PrEP delivery remain. We aimed to establish the efficiency of semiannual PrEP clinic visits supplemented with interim home-based HIV self-testing (HIVST) versus standard of care for HIV testing, drug refilling, and adherence among PrEP users. METHODS: This was a randomised, open-label, non-inferiority trial done at the Partners in Health and Research Development clinic in Thika, Kenya. Eligible participants were HIV-negative adults (≥18 years) at risk of acquiring HIV who had started PrEP at least 1 month before enrolment. Participants were randomly assigned (1:1:1) to 6-month PrEP dispensing plus interim blood-based HIVST (with biannual clinic visits), 6-month PrEP dispensing plus interim oral fluid-based HIVST (with biannual clinic visits), or standard of care PrEP delivery (3-month PrEP dispensing with quarterly clinic visits). The three coprimary outcomes, measured at 6 months, were HIV testing (any testing between enrolment and the 6-month visit), PrEP refilling, and PrEP adherence (detectable tenofovir diphosphate concentration in dried blood spots). All analyses were done according to the intention-to-treat principle. We used binomial regression models to estimate risk differences and one-sided 95% CIs. 6-month PrEP dispensing was considered non-inferior to standard of care if the lower limit bound of the one-sided 95% CI was greater than or equal to -10%. This study is registered with ClinicalTrials.gov, NCT03593629. FINDINGS: Between May 28, 2018, and Feb 24, 2020, 495 participants were enrolled: 165 men and 130 women in HIV serodifferent couples and 200 singly enrolled women. 166 participants were randomly assigned to the standard of care group, 163 to the 6-month PrEP dispensing plus oral-fluid HIVST group, and 166 to the 6-month PrEP dispensing plus blood-based HIVST group. At 6 months, 274 (83%) of 329 participants in the combined 6-month PrEP dispensing group had tested for HIV compared with 140 (84%) of 166 participants in the standard of care group (risk difference -1·15%, 95% CI lower bound -6·89). Among participants in the combined 6-month PrEP dispensing group, 257 (78%) participants refilled PrEP compared with 134 (81%) participants in the standard of care group (-2·60%, -8·88), and 200 (61%) participants were adherent to PrEP compared with 95 (57%) participants in the standard of care group (2·37%, -5·05). No participants acquired HIV during the study. INTERPRETATION: 6-month PrEP dispensing with HIVST for interim testing reduced the number of PrEP clinic visits in half without compromising HIV testing, retention, or adherence. FUNDING: US National Institute of Mental Health.

Multimonth dispensing of up to 6 months of antiretroviral therapy in Malawi and Zambia (INTERVAL): a cluster-randomised, non-blinded, non-inferiority trial.

BACKGROUND: Facility-based, multimonth dispensing of antiretroviral therapy (ART) for HIV could reduce burdens on patients and providers and improve retention in care. We assessed whether 6-monthly ART dispensing was non-inferior to standard of care and 3-monthly ART dispensing. METHODS: We did a pragmatic, cluster-randomised, unblinded, non-inferiority trial (INTERVAL) at 30 health facilities in Malawi and Zambia. Eligible participants were aged 18 years or older, HIV-positive, and were clinically stable on ART. Before randomisation, health facilities (clusters) were matched on the basis of country, ART cohort size, facility type (ie, hospital vs health centre), and region or province. Matched clusters were randomly allocated (1:1:1) to standard of care, 3-monthly ART dispensing, or 6-monthly ART dispensing using a simple random allocation sequence. The primary outcome was retention in care at 12 months, defined as the proportion of patients with less than 60 consecutive days without ART during study follow-up, analysed by intention to treat. A 2·5% margin was used to assess non-inferiority. This study is registered with ClinicalTrials.gov, NCT03101592. FINDINGS: Between May 15, 2017, and April 30, 2018, 9118 participants were randomly assigned, of whom 8719 participants (n=3012, standard of care group; n=2726, 3-monthly ART dispensing group; n=2981, 6-monthly ART dispensing group) had primary outcome data available at 12 months and were included in the primary analysis. The median age of participants was 42·7 years (IQR 36·1-49·9) and 5774 (66·2%) of 8719 were women. The primary outcome was met by 2478 (82·3%) of 3012 participants in the standard of care group, 2356 (86·4%) of 2726 participants in the 3-monthly ART dispensing group, and 2729 (91·5%) of 2981 participants in the 6-monthly ART dispensing group. After adjusting for clustering, for retention in care at 12 months, the 6-monthly ART dispensing group was non-inferior to the standard of care group (percentage-point increase 9·1 [95% CI 0·9-17·2]) and to the 3-monthly ART dispensing group (5·0% [1·0-9·1]). INTERPRETATION: Clinical visits with ART dispensing every 6 months was non-inferior to standard of care and 3-monthly ART dispensing. 6-monthly ART dispensing is a promising strategy for the expansion of ART provision and achievement of HIV treatment targets in resource-constrained settings. FUNDING: US Agency for International Development.

Simplifying TREAtment and Monitoring for HIV (STREAM HIV): protocol for a randomised controlled trial of point-of-care urine tenofovir and viral load testing to improve HIV outcomes.

INTRODUCTION: Substantial improvements in viral suppression among people living with HIV (PLHIV) are needed to end the HIV epidemic, requiring extensive scale-up of low-cost HIV monitoring services. Point-of-care (POC) tests for monitoring antiretroviral therapy (ART) adherence and viral load (VL) may be efficient and effective tools for real-time clinical decision making. We aim to evaluate the effects of a combined intervention of POC ART adherence and VL testing compared with standard-of-care on ART adherence, viral suppression and retention at 6 and 18 months post-ART initiation among PLHIV. METHODS AND ANALYSIS: Simplifying TREAtment and Monitoring for HIV (STREAM HIV) is a two-arm, open-label, randomised controlled superiority trial of POC urine tenofovir (POC TFV) and VL monitoring in PLHIV. We aim to enrol 540 PLHIV initiating a first-line ART regimen at a public HIV clinic in South Africa. Participants will be randomised 1:1 to the intervention or control arm. Intervention arm participants will receive monthly POC TFV testing for the first 5 months and POC VL testing at months 6 and 12. Intervention arm participants will also receive reflex POC TFV testing if viraemic and reflex HIV drug resistance testing for those with viraemia and detectable TFV. Control arm participants will receive standard-of-care, including laboratory-based VL testing at months 6 and 12. Primary outcomes include ART adherence (TFV-diphosphate concentration) at 6 months and viral suppression and retention at 18 months. Secondary outcomes include viral suppression and retention at 6 months, TFV-diphosphate concentration at 18 months, cost and cost-effectiveness of the intervention and acceptability of the intervention among PLHIV and healthcare workers. ETHICS AND DISSEMINATION: STREAM HIV has received ethical approval from the University of Washington Institutional Review Board (STUDY00007544), University of KwaZulu-Natal Biomedical Research Ethics Committee (BREC/00000833/2019) and Division of AIDS Regulatory Support Center (38509). Findings will be disseminated at international conferences and in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT04341779.

Immunoassay for HIV Drug Metabolites Tenofovir and Tenofovir Diphosphate.

Poor patient adherence to antiretroviral medication represents a major obstacle for managing disease and reducing rates of new HIV infections. The measurement of patient drug levels is the most objective method of determining adherence. Tenofovir and tenofovir diphosphate are metabolites of some of the most common HIV medications for treatment and prevention and can be quantified by mass spectrometry. Here, we report the development of a competitive enzyme linked immunoassay as a simplified approach for detecting tenofovir and tenofovir diphosphate. Monoclonal antibodies were produced by two tenofovir-hapten conjugates and screened for binding to immobilized tenofovir, and then for competition by tenofovir and tenofovir diphosphate. Antibody specificity was evaluated against adenosine phosphates, which are close structural analogs. We performed numerical simulations of reaction equilibrium to guide assay optimization. When used to evaluate spiked tenofovir in plasma and spiked tenofovir diphosphate in red blood cell lysate, the optimized assay had high sensitivity and specificity.

A Qualitative Assessment of Provider and Client Experiences With 3- and 6-Month Dispensing Intervals of Antiretroviral Therapy in Malawi.

INTRODUCTION: Multimonth dispensing (MMD) of antiretroviral therapy (ART) is a differentiated model of care that can help overcome health system challenges and reduce the burden of HIV care on clients. Although 3-month dispensing has been the standard of care, interest has increased in extending refill intervals to 6 months. We explored client and provider experiences with MMD in Malawi as part of a cluster randomized trial evaluating 3- versus 6-month ART dispensing. METHODS: Semi-structured in-depth interviews were conducted with 17 ART providers and 62 stable, adult clients with HIV on ART. Clients and providers were evenly divided by arm and were eligible for an interview if they had been participating in the study for 1 year (clients) or 6 months (providers). Questions focused on perceived challenges and benefits of the 3- or 6-month amount of ART dispensing. Interviews were transcribed, and data were coded and analyzed using constant comparison. RESULTS: Both clients and providers reported that the larger medication supply had benefits. Clients reported decreased costs due to less frequent travel to the clinic and increased time for income-generating activities. Clients in the 6-month dispensing arm reported a greater sense of personal freedom and normalcy. Providers felt that the 6-month dispensing interval reduced their workload. They also expressed concerned about clients' challenges with ART storage at home, but clients reported no storage problems. Although providers mentioned the potential risk of clients sharing the larger medication supply with family or friends, clients emphasized the value of ART and reported only rare, short-term sharing, mostly with their spouses. Providers mentioned clients' lack of motivation to seek care for illnesses that might occur between refill appointments. CONCLUSIONS: The 6-month ART dispensing arm was particularly beneficial to clients for decreased costs, increased time for income generation, and a greater sense of normalcy. Providers' concerns about storage, sharing, and return visits to the facility did not emerge in client interviews. Further data are needed on the feasibility of implementing a large-scale program with 6-month dispensing.

Eligibility for differentiated models of HIV treatment service delivery: an estimate from Malawi and Zambia.

BACKGROUND: Little is known about the proportion of HIV-positive clients on antiretroviral therapy (ART) who meet stability criteria for differentiated service delivery (DSD) models. We report the proportion of ART clients meeting stability criteria as part of screening for a randomized trial of multimonth dispensing in Malawi and Zambia. METHODS: For a DSD trial now underway, we screened HIV-positive clients aged at least 18 years presenting for HIV treatment in 30 adult ART clinics in Malawi and Zambia to determine eligibility for DSD. Stability was defined as on first-line ART (efavirenz/tenofovir/lamivudine) for at least 6 months, no ART side effects, no toxicity or infectious complications, no noncommunicable diseases being treated in ART clinic, no lapses in ART adherence in the prior 6 months (>30 days without taking ART), and if female, not pregnant or breastfeeding. RESULTS: In total, 3465 adult ART clients were approached between 10 May 2017 and 30 April 2018 (Malawi: 1680; Zambia: 1785). Of the 2938 who answered screening questions (Malawi: 1527; Zambia: 1411), 2173 (73.5%) met criteria for DSD eligibility (Malawi: 72.8%; Zambia: 74.3%). The most common reasons for ineligibility were being on ART less than 6 months (9.6%) and a regimen other than standard first-line (7.9%). CONCLUSION: Approximately three-quarters of all adult clients presenting at ART clinics in Malawi and Zambia were eligible for DSD using a typical definition of stability. High uptake of DSD models by eligible clients would have a major impact on the infrastructure and the allocation of HIV treatment resources.

Towards the third 90: improving viral load testing with a simple quality improvement program in health facilities in Malawi.

BACKGROUND: Viral load (VL) scale-up efforts have largely focused on laboratory systems, with less attention on facility-level strengthening of staff who facilitate VL testing. To address this gap we implemented a quality improvement (QI) program at 13 health facilities in central and southern Malawi. METHODS: QI program tools focused on patient and provider VL knowledge and clarification of site-level roles and responsibilities, including the designation of a VL 'focal person' to oversee all VL activities. T-tests were used to compare differences in VL testing before (November 2016-April 2017) and after (May 2017-November 2017) the intervention. RESULTS: The mean number of VL tests performed significantly increased after implementation of the QI program. Overall there was a 164% increase in the mean number of routine VL tests performed per month (p<0.001). Increased VL testing was sustained during the 6 months of follow-up. CONCLUSIONS: A simple QI program focused on improving VL knowledge among patients and providers, and clarifying staff roles at a facility level increased VL testing over a 6-month period. Further investigation is needed on whether this program can be scaled in different settings across sub-Saharan Africa and on the duration of follow-up required for sustained improvements in VL testing.

Evaluating the integration of HIV self-testing into low-resource health systems: study protocol for a cluster-randomized control trial from EQUIP Innovations.

BACKGROUND: Throughout sub-Saharan Africa HIV-testing rates remain low. Barriers to testing, such as inconvenient service hours and long wait times, lack of privacy, and fear of unwanted disclosure, continue to impede service utilization. HIV self-testing (HIVST) is one strategy that addresses these barriers and has been shown to increase use of HIV-testing when distributed through community-based settings. However, the scalability of HIVST is limited because it has yet to be fully integrated into existing health systems and routine care. To address this gap, we designed a study to test the effect of offering HIVST to routine outpatient department (OPD) clients on uptake of HIV-testing as compared to standard of care and optimized standard of care. METHODS/DESIGN: This is a non-blinded, multi-site, cluster-randomized control trial. The health facility is the unit of randomization (cluster). Fifteen facilities were randomized to one of three arms: (1) Standard of care using routine provider-initiated testing and counseling (PITC); (2) Optimized standard of care using optimized PITC defined by additional training, job aids, and monitoring of PITC strategies with OPD providers and support staff; and (3) HIVST defined by HIVST demonstrations for OPD clients, HIVST kit distribution, and private spaces for HIVST kit use and/or interpretation. The primary outcome is the proportion of OPD clients tested for HIV on the day that they accessed OPD services. Secondary outcome measures are the proportion of OPD clients newly identified as HIV-positive and antiretroviral therapy (ART) initiation. Costs and cost-effectiveness will be evaluated. Nested studies will determine the acceptability of facility-based HIVST among OPD clients and health care providers, the presence of adverse events, such as coercion to test or unwanted status disclosure, and a process evaluation to determine feasibility and scale-up of facility-based HIVST for the future. DISCUSSION: This study protocol tests whether facility-based HIVST can positively contribute to HIV-testing among OPD clients in resource-limited settings. This will be one of the first studies to test the integration of HIVST into facility-based, primary health services in sub-Saharan Africa. TRIAL REGISTRATION: ClinicalTrials.gov, ID: NCT03271307 . Registered on 31 August 2017. Pan African Clinical Trials: PACTR201711002697316 . Registered on 1 November 2017.

Varying intervals of antiretroviral medication dispensing to improve outcomes for HIV patients (The INTERVAL Study): study protocol for a randomized controlled trial.

BACKGROUND: Requirements for frequent dispensing of antiretroviral therapy (ART) place demands on health systems and can lead to suboptimal adherence and disengagement in care for patients due to the time and cost of frequent clinic visits. Rigorous data are needed to define optimal ART dispensing strategies and to evaluate the impact of a longer medication supply on retention and virologic suppression and determine whether this strategy lowers costs for both the patient and the health system. To date, no randomized studies have tested the benefits of 6-month dispensing of ART compared to 3-month and standard of care approaches. METHODS: This study will be an unblinded cluster-randomized, matched controlled trial conducted among 8200 stable, HIV-infected individuals age 18 years and older on ART in Malawi and Zambia, to compare three ART dispensing intervals on the outcomes of retention in care (primary outcome), virologic suppression, and cost-effectiveness. Thirty clusters will be matched according to country, facility type, and ART cohort size and randomized to one of three study arms: standard of care, 3-month dispensing, and 6-month dispensing. Study participants will be followed, and outcomes will be measured at 12, 24, and 36 months. A subset of participants (n = 240) and providers (n = 180) will also participate in qualitative interviews to evaluate feasibility and acceptability of different ART dispensing intervals. DISCUSSION: This study will be the first to compare 6-month and 3-month ART dispensing intervals for stable, HIV-infected individuals in Malawi and Zambia. We focus on outcomes relevant to country programs, including retention, virologic suppression, and cost-effectiveness. Results from the study will help resource-limited health systems better understand the full scope of outcomes resulting from various ART dispensing intervals and help to inform health policy decisions. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03101592 . Registered on 18 March 2017. Pan African Clinical Trials, PACTR201706002336105 . Registered on 2 June 2017.