Development of Ingestible Biosensors to Enhance PrEP Adherence in Substance Users (PrEPSteps) (PrEPSteps)

September 13, 2025 updated by: Peter R Chai MD, Brigham and Women's Hospital
This study will deploy a novel, personalized, smartphone-based intervention (PrEPSteps) that responds to real-time PrEP adherence and nonadherence detected through the use of a digital pill. The PrEPSteps intervention will be developed and refined through a series of focus groups. Participants will be screened at the Screening Visit, and, if eligible, will then begin using the digital pill system at Study Visit 1 for 2 weeks. At Study Visit 2, participants will undergo randomization to using either PrEPSteps + the digital pill, or the digital pill alone to measure PrEP adherence, for 90 days. Participants will then complete 3 monthly study visits (Study Visits 3-5) where the investigators will assess digital pill adherence, conduct manual pill counts, obtain dried blood spots to confirm adherence, provide substance use disorder counseling, and obtain urine drug screens. At Study Visit 5, the investigators will conduct a semi-structured qualitative interview with participants in the PrEPsteps arm, which will be grounded in the Technology Acceptance Model, in order to understand the user response to PrEPSteps and the digital pill. All participants will complete the final follow-up assessment 3 months after Study Visit 5 (Study Visit 6).

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

PrEPSteps is a novel, smartphone-based behavioral intervention that delivers PrEP adherence messages in response to detected PrEP ingestion via an innovative digital pill. PrEPSteps comprises 1) an adaptation of LifeSteps, an evidence-based medication adherence behavioral intervention, with smartphone-delivered booster sessions, 2) messages of contingent reinforcement and corrective feedback, and 3) stimulant use screening, brief assessment, and referral to treatment. In this K23, the investigators will first refine and inform the specification of PrEPSteps with a series of focus groups. The investigators will next test the feasibility, acceptability and potential for an effect of PrEPSteps to boost PrEP adherence in a pilot randomized controlled trial of men who have sex with men (MSM) with stimulant use. Finally, the investigators will conduct qualitative interviews among participants who used PrEPSteps to understand the participant response to living with the intervention.

Study Type

Interventional

Enrollment (Actual)

30

Phase

  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Massachusetts
      • Boylston, Massachusetts, United States, 02215
        • Fenway Health

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

14 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Cisgender MSM
  • Moderate to severe non-alcohol substance use disorder
  • Self-reported missed PrEP doses (> or equal to 2 doses in 1 week over past 3 months)
  • HIV negative
  • On PrEP or initiating PrEP
  • Has qualifying laboratory testing: Cr clearance, HBV, liver function tests
  • Owns a smartphone with Android or iOS
  • Age 18 or older

Exclusion Criteria:

  • Non-English speaker
  • HIV positive
  • History of Crohn's disease or ulcerative colitis
  • History of gastric bypass, bowel stricture
  • History of GI malignancy or radiation to abdomen
  • Unable/unwilling to ingest a digital pill
  • Allergy to gelatin, silver or zinc (components of the digital pill)
  • Does not qualify for PrEP (abnormal liver function, or Cr Clearance <60)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: PrEPsteps
Participants receive the digital pills with Truvada, plus the PrEPsteps intervention that is programmed at the randomization study visit (Study Visit 2). Participants will use PrEPsteps and the digital pill to measure Truvada adherence for months 1-3.
Behavioral: PrEPsteps
Smartphone-based adherence intervention based in 1) LifeSteps, 2) Contingent Reinforcement/Corrective Feedback, and 3) Screening Brief Intervention and Referral to Treatment (SBIRT).
Device: Digital pill
The digital pill comprises a standard gelatin capsule with an integrated radiofrequency emitter that overencapsulates the desired medication (Truvada). When participants ingest the digital pill, the chloride ion gradient in the stomach activates the radiofrequency emitter which transmits direct evidence of medication ingestion to a wearable reader which relays this data to the participant's smartphone and cloud server.
Drug: Truvada
Participants receive once daily Truvada as PrEP to prevent HIV.
Active Comparator: Control
Participants receive digital pills with Truvada alone. Participants will use digital pills with Truvada for months 1-3.
Device: Digital pill
The digital pill comprises a standard gelatin capsule with an integrated radiofrequency emitter that overencapsulates the desired medication (Truvada). When participants ingest the digital pill, the chloride ion gradient in the stomach activates the radiofrequency emitter which transmits direct evidence of medication ingestion to a wearable reader which relays this data to the participant's smartphone and cloud server.
Drug: Truvada
Participants receive once daily Truvada as PrEP to prevent HIV.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Feasibility of the Adherence Intervention Qualitative and Quantitive Questionnaire
Time Frame: three month study visit
Number of participants who were able to complete the trial and record adherence events using the digital pill system in the intervention arm.
three month study visit

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Potential of PrEPsteps to Improve Adherence
Time Frame: three month study visit
Number of digital pill recorded ingestions at week 13 (end of intervention period) recorded as percent adherence
three month study visit
Number of People Who Found the Digital Pill Acceptable to Use Within the Intervention Arm
Time Frame: three month visit
Qualitative interviews asking participants if they found the use of the digital pill system acceptable and did not interfere with their daily PrEP use. This outcome was only assessed in the PrEPSteps (intervention arm) only.
three month visit

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Accuracy of Digital Pill Compared to Pill Counts and Dried Blood Spot for Adherence
Time Frame: one and three month study visits
Accuracy of digital pill in measuring PrEP adherence as compared to dried blood spot testing for tenofovir diphosphate
one and three month study visits

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Brigham and Women's Hospital

Collaborators

National Institute on Drug Abuse (NIDA)
Gilead Sciences
The Fenway Institute

Investigators

  • Principal Investigator: Peter R Chai, MD, MMS, Brigham and Women's Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 20, 2019

Primary Completion (Actual)

April 10, 2024

Study Completion (Actual)

April 10, 2024

Study Registration Dates

First Submitted

March 21, 2018

First Submitted That Met QC Criteria

April 19, 2018

First Posted (Actual)

April 30, 2018

Study Record Updates

Last Update Posted (Estimated)

September 17, 2025

Last Update Submitted That Met QC Criteria

September 13, 2025

Last Verified

September 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2019P000792
  • K23DA044874 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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