Pharmacokinetics of Coencapsulated Antiretrovirals with Ingestible Sensors

A proposal for a simplified measure of HIV preexposure prophylaxis prevention-effective adherence in self-report questionnaires

Evaluating HIV preexposure prophylaxis (PrEP) use and HIV risk events concurrently remains challenging. We developed a single question method for measuring prevention-effective adherence with PrEP in self-report questionnaires. In a questionnaire completed by 409 gay and bisexual men, 46% reported condomless anal sex that was not covered by their own PrEP use, and this was more common among younger, lower-income participants. Refining this questionnaire item could improve measurement of prevention-effective adherence.

Adherence to Antiretrovirals and HIV Viral Suppression Under COVID-19 Pandemic Interruption - Findings from a Randomized Clinical Trial Using Ingestible Sensors to Monitor Adherence

The COVID-19 pandemic had a significant impact on vulnerable populations, including people living with HIV. California implemented a coronavirus lockdown (stay-at-home order) in March 2020, which ended in January 2021. We evaluated the pandemic's impact on both clinical outcomes of HIV RNA viral load (VL) and retention rate in a randomized clinical trial conducted from May 2018 to October 2020. The intervention group took co-encapsulated antiretrovirals (ARVs) with ingestible sensor (IS) pills from baseline through week 16. The IS system has the capacity to monitor adherence in real-time using a sensor patch, a mobile device, and supporting software. Both the IS and usual care (UC) groups were followed monthly for 28 weeks. Longitudinal mixed-effects models with random intercept and slope (RIAS) were used to fit log VL and self-reported adherence. The sample size of the study was 112 (54 in IS). Overall, the retention rate at week 28 was 86%, with 90% before the lockdown and 83% after the lockdown. The lockdown strengthened the associations between adherence and VL. Before the lockdown, a 10% increase in adherence was associated with a 0.2 unit decrease in log VL (β = -1.88, p = 0.004), while during the lockdown, the association was a 0.41-unit decrease (β = -2.27, p = 0.03). The pandemic did not have a significant impact on our adherence-focused intervention. Our findings regarding the intervention effect remain valid. TRIAL REGISTRATION NUMBER: NCT02797262. Date registration: September 2015.

Bibliometric analysis and evidence of clinical efficacy and safety of digital pills

Objectives: Digital pills are new technologies that aim to improve healthcare by increasing medication adherence. The aim of the work was a bibliometric analysis of clinical studies of digital pills and an assessment of the level of evidence of their effectiveness, safety, and prospects for the future. Materials and Methods: The studies were conducted using online databases such as ClinicalTrials.gov, Dimensions, and Web of Science for the period January 2012 to July 2022. The VOSviewer tool for building and visualizing bibliometric networks was used. Results: Bibliometric analysis of the scientific literature revealed that over the past 10 years, the number of publications about digital pills has noticeably increased, which indicates the increasing importance of this field of knowledge. The leading positions in this area are occupied by scientists from the United States, the United Kingdom, and India. Sources of financial support for authors of publications in the field of digital pills are funds from leading developer companies, budget allocations, and funds from non-commercial organizations. Public-private partnerships are an important path to develop and implement digital pills. The four main clusters of digital pill studies were highlighted and visualized: efficacy and safety analysis for serious mental disorders; treatment and costs of tuberculosis therapy; features of the treatment of diabetes, cardiovascular diseases, and AIDS; and usage monitoring. Available publications demonstrate the efficacy potential and safety of digital pills. Nevertheless, the effects of digital pills have not yet been fully studied. Conclusion: Priority areas for future research are further randomized controlled clinical trials and meta-analyses, which are necessary for a high level (I level) of evidence for therapeutic applications of digital pills, as well as pharmacoeconomic studies.

Ingestible sensor system for measuring, monitoring and enhancing adherence to antiretroviral therapy: An open-label, usual care-controlled, randomised trial

BACKGROUND

Co-encapsulated antiretrovirals (ARVs) with ingestible sensor (IS) has the capacity to monitor adherence in real-time using a sensor patch, a mobile device, and supporting software. We evaluated the acceptability, effectiveness, and sustainability of the IS system with real-time text reminders.

METHODS

Participants were recruited from HIV clinics in Los Angeles and were randomised 1:1 to IS or usual care (UC) group. Adherence to ARVs (primary outcome) was measured by IS system (IS group only), plasma ARV concentration, and self-report. IS-measured adherence was clustered by group-based trajectory model and was validated by ARV concentration summarized by integrated pharmacokinetic adherence measure (IPAM) score. HIV RNA viral load (VL) was compared between IS and UC group.

FINDINGS

A total of 112 (IS = 54, UC = 58) participants who completed baseline with at least one follow-up data collection were included in analyses. Overall satisfaction rate for the IS system was >90%. The IPAM score was higher (0.018, 95% CI: -0.098-0.134, p = 0.75) and VL decayed faster (-0.020, 95% CI: -0.042-0.002, p = 0.08) in the IS group compared with the UC group. The ingestible sensor system was well tolerated by study participants.

INTERPRETATION

The IS system was well accepted by participants and its use was associated with improved adherence and lower HIV RNA VL. The findings provide a potentially effective strategy for improving adherence.

FUNDING

This work was supported by grant R01-MH110056 from the National Institute of Mental Health (NIMH)/National Institutes of Health (NIH). Y. Wang was in part supported by the NIMH/NIH award T32MH080634. E. Daar was in part supported by the National Center for Advancing Translational Sciences through UCLACTSI Grant UL1TR001881. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.

Ingestible Electronic Sensors for Monitoring Real-time Adherence to HIV Pre-exposure Prophylaxis and Antiretroviral Therapy

PURPOSE OF REVIEW

This review summarizes the recent advancements and future directions of digital pill systems (DPS) - which utilize ingestible sensors to directly measure medication ingestion events in real-time - in the context of HIV prevention and treatment.

RECENT FINDINGS

Two DPS are cleared by the US Food and Drug Administration. The bioequivalence and stability of digitized pre-exposure prophylaxis (PrEP) and antiretroviral therapy (ART) have been established, and pilot studies have demonstrated the feasibility and acceptability of using DPS for PrEP and ART adherence measurement. Important bioethical and implementation considerations have been identified for future clinical trials. Continued technological advancement may reduce barriers to use, and integration of DPS into behavioral interventions may facilitate adherence improvement efforts. DPS represent an innovative tool for PrEP and ART adherence measurement. Future work will optimize the technology to reduce operational barriers. DPS have significant potential for expansion across a diverse array of diseases, though key bioethical considerations must be examined prior to large-scale implementation.

Long-Term Stability of the Electronic Sensor Component of a Digital Pill System in Real-World Storage Settings

Background: Digital pill systems comprise an ingestible sensor integrated into a gelatin capsule that overencapsulates medication allowing real-time measures of medication ingestion. These systems may improve the manner in which medication adherence can be assessed and supported. Objective: In this investigation, we tested the durability of the ingestible sensor as part of a clinical trial to measure the feasibility and acceptability of the system to measure adherence to once daily tenofovir disoproxil fumarate/emtricitabine (NCT03842436). Methods: Digital pills not dispensed during the study were stored in a pharmacy. Seventeen sensors were selected from digital pills stored for at least 12 months and activated in a simulated gastric environment. A radiofrequency spectrum analyzer and the reader device used in the clinical trial to capture ingestion events were used to measure activation of emitters. A passing evaluation was defined as an energized emitter within 30 minutes of immersion, ability to broadcast a signal for 10 minutes, and successful acquisition by the reader. Results: All ingestible sensors passed the stability test. Mean activation time in simulated gastric fluid was 3.33 minutes (SD = 1.47); emitters remained active for a mean of 47.72 minutes (SD = 1.78). These parameters matched guidelines defined in the ID-Cap system requirements for use in patients. Conclusions: Ingestible sensor components of the ID-Cap system were therefore stable after long-term storage.

Smart pills for gastrointestinal diagnostics and therapy

Ingestible smart pills have the potential to be a powerful clinical tool in the diagnosis and treatment of gastrointestinal disease. Though examples of this technology, such as capsule endoscopy, have been successfully translated from the lab into clinically used products, there are still numerous challenges that need to be overcome. This review gives an overview of the research being done in the area of ingestible smart pills and reports on the technical challenges in this field.

Design and Delivery of Real-Time Adherence Data to Men Who Have Sex with Men Using Antiretroviral Pre-exposure Prophylaxis via an Ingestible Electronic Sensor

Once daily tenofovir/emtricitabine when used for pre-exposure prophylaxis (PrEP) is effective in preventing HIV acquisition but requires consistent medication adherence. The use of ingestible technologies to monitor PrEP adherence can assist in understanding the impact of behavioral interventions. Digital pill systems (DPS) utilize an ingestible radiofrequency emitter integrated onto a gelatin capsule, which permits direct, real-time measurement of medication adherence. DPS monitoring may lead to discovery of nascent episodes of PrEP nonadherence and allow delivery of interventions that prevent the onset of sustained nonadherence. Yet, the acceptance and potential use of DPS in high-risk men who have sex with men (MSM; i.e., those who engage in condomless sex and use substances) is unknown. In this investigation, we conducted individual, semi-structured qualitative interviews with 30 MSM with self-reported non-alcohol substance use to understand their responses to the DPS, willingness and perceived barriers to its use, and their perceptions of its potential utility. We also sought to describe how MSM would potentially interact with a messaging system integrated into the DPS. We identified major themes around improved confidence of PrEP adherence patterns, safety of ingestible radiofrequency sensors, and design optimization of the DPS. They also expressed willingness to interact with messaging contingent on DPS recorded ingestion patterns. These data demonstrate that MSM who use substances find the DPS to be an acceptable method to measure and record PrEP adherence.

DOT Diary: Developing a Novel Mobile App Using Artificial Intelligence and an Electronic Sexual Diary to Measure and Support PrEP Adherence Among Young Men Who Have Sex with Men

Young men who have sex with men (YMSM) are highly vulnerable to HIV. While pre-exposure prophylaxis (PrEP) has demonstrated effectiveness, adherence has been low among YMSM and difficult to measure accurately. In collaboration with a healthcare company, we configured an automated directly-observed therapy (aDOT) platform for monitoring and supporting PrEP use. Based on interest expressed in focus groups among 54 YMSM, we combined aDOT with an electronic sexual diary to provide feedback on level of protection during sex and to motivate app use. In an 8-week optimization pilot with 20 YMSM in San Francisco and Atlanta, the app was found to be highly acceptable, with median System Usability Scale scores in the "excellent" range (80/100). App use was high, with median PrEP adherence of 91% based on aDOT-confirmed dosing. Most (84%) participants reported the app helped with taking PrEP. These promising findings support further evaluation of DOT Diary in future effectiveness studies.

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.