Trial Outcomes & Findings for Development of Ingestible Biosensors to Enhance PrEP Adherence in Substance Users (PrEPSteps) (NCT NCT03512418)
NCT ID: NCT03512418
Last Updated: 2025-09-17
Results Overview
Number of participants who were able to complete the trial and record adherence events using the digital pill system in the intervention arm.
COMPLETED
PHASE3
30 participants
three month study visit
2025-09-17
Participant Flow
Participants were recruited from a health clinic in Boston, MA. We also conducted community-based outreach in the greater Boston metropolitan area through flyers and postings. Interested participants contacted the study team and were prescreened for eligibility criteria.
Potentially eligible participants were consented and started on the digital pill system (DPS). Standardized training was completed and participants were asked to use the DPS for 2 weeks as a run-in period prior to randomization.
Participant milestones
| Measure |
PrEPSteps (Intervention)
A text-based cognitive behavioral adherence intervention delivered in response to adherence data obtained through a digital pill system (ingestible radio frequency system co-encapsulated with tenofovir disoproxil fumarate/emtricitabine). In response to nonadherence dates detected by the digital pill, PrEPSteps sends personalized adherence interventions presenting barriers to adherence and solutions to these barriers in real-time.
|
Control
Operation of the digital pill system to measure daily adherence to tenofovir disoproxil fumarate/emtricitabine. Participants were trained on the use of the digital pill system and asked to operate it daily to record adherence.
|
|---|---|---|
|
Overall Study
STARTED
|
15
|
15
|
|
Overall Study
COMPLETED
|
14
|
14
|
|
Overall Study
NOT COMPLETED
|
1
|
1
|
Reasons for withdrawal
Withdrawal data not reported
Baseline Characteristics
Development of Ingestible Biosensors to Enhance PrEP Adherence in Substance Users (PrEPSteps)
Baseline characteristics by cohort
| Measure |
PrEPSteps (Intervention)
n=14 Participants
A text-based cognitive behavioral adherence intervention delivered in response to adherence data obtained through a digital pill system (ingestible radio frequency system co-encapsulated with tenofovir disoproxil fumarate/emtricitabine). In response to nonadherence dates detected by the digital pill, PrEPSteps sends personalized adherence interventions presenting barriers to adherence and solutions to these barriers in real-time.
|
Control
n=14 Participants
Operation of the digital pill system to measure daily adherence to tenofovir disoproxil fumarate/emtricitabine. Participants were trained on the use of the digital pill system and asked to operate it daily to record adherence.
|
Total
n=28 Participants
Total of all reporting groups
|
|---|---|---|---|
|
Age, Continuous
|
38 years
n=99 Participants
|
37.5 years
n=107 Participants
|
37.5 years
n=206 Participants
|
|
Sex: Female, Male
Female
|
0 Participants
n=99 Participants
|
0 Participants
n=107 Participants
|
0 Participants
n=206 Participants
|
|
Sex: Female, Male
Male
|
14 Participants
n=99 Participants
|
14 Participants
n=107 Participants
|
28 Participants
n=206 Participants
|
|
Ethnicity (NIH/OMB)
Hispanic or Latino
|
2 Participants
n=99 Participants
|
3 Participants
n=107 Participants
|
5 Participants
n=206 Participants
|
|
Ethnicity (NIH/OMB)
Not Hispanic or Latino
|
12 Participants
n=99 Participants
|
11 Participants
n=107 Participants
|
23 Participants
n=206 Participants
|
|
Ethnicity (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=99 Participants
|
0 Participants
n=107 Participants
|
0 Participants
n=206 Participants
|
|
Race (NIH/OMB)
American Indian or Alaska Native
|
0 Participants
n=99 Participants
|
1 Participants
n=107 Participants
|
1 Participants
n=206 Participants
|
|
Race (NIH/OMB)
Asian
|
1 Participants
n=99 Participants
|
0 Participants
n=107 Participants
|
1 Participants
n=206 Participants
|
|
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
|
0 Participants
n=99 Participants
|
0 Participants
n=107 Participants
|
0 Participants
n=206 Participants
|
|
Race (NIH/OMB)
Black or African American
|
0 Participants
n=99 Participants
|
1 Participants
n=107 Participants
|
1 Participants
n=206 Participants
|
|
Race (NIH/OMB)
White
|
12 Participants
n=99 Participants
|
9 Participants
n=107 Participants
|
21 Participants
n=206 Participants
|
|
Race (NIH/OMB)
More than one race
|
1 Participants
n=99 Participants
|
3 Participants
n=107 Participants
|
4 Participants
n=206 Participants
|
|
Race (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=99 Participants
|
0 Participants
n=107 Participants
|
0 Participants
n=206 Participants
|
|
Number of sexual partners
|
14.8 partners
n=99 Participants
|
3.36 partners
n=107 Participants
|
3.5 partners
n=206 Participants
|
|
Substance use during sex
|
3.5 events
n=99 Participants
|
2.5 events
n=107 Participants
|
3 events
n=206 Participants
|
PRIMARY outcome
Timeframe: three month study visitNumber of participants who were able to complete the trial and record adherence events using the digital pill system in the intervention arm.
Outcome measures
| Measure |
PrEPsteps
n=14 Participants
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.
|
Control
n=14 Participants
Participants receive digital pills with Truvada alone. Participants will use digital pills with Truvada for months 1-3.
|
|---|---|---|
|
Feasibility of the Adherence Intervention Qualitative and Quantitive Questionnaire
|
14 Participants
|
14 Participants
|
SECONDARY outcome
Timeframe: three month study visitNumber of digital pill recorded ingestions at week 13 (end of intervention period) recorded as percent adherence
Outcome measures
| Measure |
PrEPsteps
n=14 Participants
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.
|
Control
n=14 Participants
Participants receive digital pills with Truvada alone. Participants will use digital pills with Truvada for months 1-3.
|
|---|---|---|
|
Potential of PrEPsteps to Improve Adherence
|
86 percentage of pills taken appropriately
Standard Deviation 17.23
|
72 percentage of pills taken appropriately
Standard Deviation 33.14
|
SECONDARY outcome
Timeframe: three month visitPopulation: Only intervention arm (PrEPSteps) completed qualitative interviews at the 3 month study endpoint for this outcome.
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.
Outcome measures
| Measure |
PrEPsteps
n=14 Participants
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.
|
Control
Participants receive digital pills with Truvada alone. Participants will use digital pills with Truvada for months 1-3.
|
|---|---|---|
|
Number of People Who Found the Digital Pill Acceptable to Use Within the Intervention Arm
|
14 Participants
|
—
|
OTHER_PRE_SPECIFIED outcome
Timeframe: one and three month study visitsAccuracy of digital pill in measuring PrEP adherence as compared to dried blood spot testing for tenofovir diphosphate
Outcome measures
Outcome data not reported
Adverse Events
PrEPsteps
Control
Serious adverse events
Adverse event data not reported
Other adverse events
Adverse event data not reported
Additional Information
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place