The PrEP (Pre-exposure Prophylaxis) SMART Study

April 30, 2026 updated by: Connie Celum, University of Washington

Evaluation of Stepped PrEP (Pre-exposure Prophylaxis) Adherence Support for Young South African Women Using a SMART Design

The PrEP SMART study is testing a stepped model of scalable adherence support strategies in South African young women who initiate PrEP using a SMART (sequential multiple assignment randomized trial) design.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Women enrolled in the study will be randomized to standard of care adherence support (brief counseling) and either WhatsApp groups or weekly two-way SMS messages. Two months after PrEP initiation, tenofovir drug levels will be measured to determine if participants have achieved high adherence based on their initial randomization. Women with high adherence (i.e., TFV-DP >/=500 fmol/punch from dried blood spots [DBS]) will continue with the adherence support to which they were initially randomized. Participants with low adherence (i.e., TFV-DP <500 fmol/punch from DBS) will continue initial randomization (WhatsApp or two-way SMS) plus be randomized to more one of two more intensive adherence support interventions - continued monthly visits with adherence and problem-focused counseling at months 3-8 or quarterly visits between months 3-9 with feedback about adherence based on drug levels at months 3 and 6.

Study Type

Interventional

Enrollment (Actual)

360

Phase

  • Not Applicable

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

  • South Africa
      • Johannesburg, South Africa
        • Wits Reproductive Health and HIV Institute

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 to 21 years (Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Female at birth
  • Age 18-25 years
  • Per participant report, sexually active, defined as having vaginal or anal intercourse at least once in the month prior to screening
  • Literate in one or more of the study languages
  • Willing and able to provide informed consent
  • Able and willing to provide adequate locator information
  • Regular access to a mobile phone with SMS and WhatsApp capacity
  • Agrees not to participate in other research studies involving drugs or medical devices for the duration of study participation

Exclusion Criteria:

  • Planning to relocate in the next 12 months
  • Has a job or other obligations that would require long absences from the area (> 4 weeks at a time) for 12 months
  • A reactive or positive HIV test at Enrollment
  • Any reported PrEP use within the last 6 months
  • Concomitant participation in a clinical trial using investigational agents, including placebo-controlled clinical trials using such agents
  • Prior participation in the active arm, or current participation in any arm, of an HIV vaccine trial
  • Positive pregnancy test

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: Sequential Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: WhatsApp Group
Participants will be assigned to participate in a WhatsApp Group
Behavioral: WhatsApp Group
Participants will receive peer adherence support through WhatsApp groups
Experimental: 2-way SMS
Participants will be assigned to receive weekly 2-way SMS initiated by the study team
Behavioral: 2-way SMS
Participants will receive healthcare worker adherence support through 2-way SMS
Experimental: 2-way SMS and monthly counseling sessions
Participants will be assigned to receive weekly 2-way SMS initiated by the study team and monthly counseling sessions
Behavioral: 2-way SMS
Participants will receive healthcare worker adherence support through 2-way SMS
Behavioral: Monthly counseling sessions
Participants will receive monthly counseling on a variety of issues that may be impacting their PrEP adherence
Experimental: 2-way SMS and drug level feedback
Participants will be assigned to receive weekly 2-way SMS initiated by the study team and drug level feedback
Behavioral: 2-way SMS
Participants will receive healthcare worker adherence support through 2-way SMS
Behavioral: Drug level feedback
Participants will receive adherence counseling based on tenofovir drug levels
Experimental: WhatsApp Group and monthly counseling sessions
Participants will be assigned to participate in a WhatsApp Group and monthly counseling sessions
Behavioral: WhatsApp Group
Participants will receive peer adherence support through WhatsApp groups
Behavioral: Monthly counseling sessions
Participants will receive monthly counseling on a variety of issues that may be impacting their PrEP adherence
Experimental: WhatsApp Group and drug level feedback
Participants will be assigned to participate in a WhatsApp Group and drug level feedback
Behavioral: WhatsApp Group
Participants will receive peer adherence support through WhatsApp groups
Behavioral: Drug level feedback
Participants will receive adherence counseling based on tenofovir drug levels

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
PrEP Adherence
Time Frame: 9 months
Evaluation of the proportion of young women who adhere well to PrEP in each of the original intervention arms.
9 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Probability of High PrEP Adherence at Nine Months
Time Frame: 9 months

Estimated probability of high PrEP adherence (tenofovir diphosphate levels greater than or equal to 700 fmol/punch at 9 months) by embedded dynamic treatment strategy.

This analysis employed a weighted and replicated approach to account for non-response, re-randomization, and overlap in intervention assignments (e.g., the same participants in the SMS intervention were represented twice in two of the four interventions). Weighting accounted for over-representation of people who responded, whereas replicating responder observations across the two embedded dynamic treatment strategies with the same first-line treatment accounted for one participant being able to be in two treatment strategies.
9 months
PrEP Discontinuation
Time Frame: 9 months
Assessment of the timing of PrEP discontinuation in young women who discontinue PrEP, reported by original intervention arm.
9 months

Collaborators and Investigators

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

Sponsor

University of Washington

Collaborators

National Institute of Mental Health (NIMH)
Wits Reproductive Health and HIV Institute

Investigators

  • Principal Investigator: Sinead Delany-Moretlwe, MBChB, PhD, Wits Reproductive Health and HIV Institute
  • Principal Investigator: Connie Celum, MD, MPH, University of Washington

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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)

May 16, 2019

Primary Completion (Actual)

October 27, 2021

Study Completion (Actual)

January 25, 2022

Study Registration Dates

First Submitted

June 19, 2019

First Submitted That Met QC Criteria

July 26, 2019

First Posted (Actual)

July 30, 2019

Study Record Updates

Last Update Posted (Actual)

May 4, 2026

Last Update Submitted That Met QC Criteria

April 30, 2026

Last Verified

April 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • STUDY00006439
  • R01MH114544 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Data from the PrEP SMART Study will be available at the end of the project by contacting the Principal Investigators.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

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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