Duo: A Phase IIIb Individual-Level Randomized Controlled Trial of an Integrated Strategy

Duo: A Phase IIIb Individual-Level Randomized Controlled Trial of an Integrated Strategy of HIV PrEP and STI PEP for Young Men

Individual-Level Randomized Controlled Trial of an Integrated Strategy of HIV pre-exposure prophylaxis (PrEP) and sexually transmitted infection (STI) post-exposure prophylaxis (PEP) for Young Men

Study Overview

• Status: Not yet recruiting
• Conditions: HIV Infection; Sexually Transmitted Infection
• Intervention / Treatment: Drug: HIV PrEP - choice of F/TDF, F/TAF, or CAB-LA; Drug: STI PEP - Doxycycline as Doxy-PEP; Behavioral: 3P mHealth package; Behavioral: Handout about HIV PrEP options available at the site; Behavioral: Standard-of-care HIV PrEP counseling from qualified study staff

Detailed Description

This study will test a suite of mHealth tools to increase HIV pre-exposure prophylaxis (PrEP) uptake and adherence among young men in communities most affected by the HIV epidemic and evaluate the uptake, adherence, and acceptability of doxycycline for sexually transmitted infection (STI) post-exposure prophylaxis (doxy-PEP).

• Study Type: Interventional
• Enrollment (Estimated): 400
• Phase: Phase 3

Contacts and Locations

• Study Contact: Name: Michelle Robinson; Phone Number: 919-321-3585; Email: mrobinson@fhi360.org
• Study Contact Backup: Name: Kailazarid Gomez-Feliciano, MPM; Phone Number: 919-321-3486; Email: kgomez@fhi360.org

Study Locations

• Argentina
  • Buenos Aires, Argentina, C1427CEA
    • Fundacion Huesped CRS
    • Contact: Maria Figueroa; Phone Number: 1132 54-11-49817777; Email: maria.figueroa@huesped.org.ar
• Brazil
  • Rio de Janeiro
    • Manguinhos, Rio de Janeiro, Brazil, 221045-900
      • Instituto de Pesquisa Clinicaq Evandro Chagas CRS
• Peru
  • Lima, Peru, 32-15088
    • San Miguel CRS
    • Contact: Javier Valencia; Phone Number: 51-1948081626; Email: jvalencia@impactaperu.org
• United States
  • California
    • Los Angeles, California, United States, 90095
      • UCLA Vine Street Clinic
      • Contact: Jesse Clark, MD; Phone Number: 323-461-3106; Email: jlclark@mednet.ucla.edu
  • New York
    • The Bronx, New York, United States, 10451
      • Bronx Prevention Research Center CRS
      • Contact: Ellen Morrison; Phone Number: 212-305-6328; Email: eam6@cumc.columbia.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

1. Men ages 18 - 29 years
2. Men who are in communities most affected by the HIV epidemic
3. Willing and able to provide informed consent
4. Reports having anal sex with men in the last 6 months

5. Have certain risk factors for HIV acquisition, defined as any of the following in the past 6 months:

   1. Any condomless anal sex with a man; not including within a monogamous relationship with an HIV-negative partner or an HIV-positive partner who is virally suppressed
   2. Reporting 2 or more male partners, regardless of condom use
   3. Reporting gonorrhea, chlamydia, or syphilis diagnosis
   4. Any stimulant use (e.g., cocaine, amphetamines)
6. Not on PrEP within the past 3 months due to participant choice
7. Interested in learning more about PrEP or starting PrEP
8. No evidence of HIV infection at Screening and Enrollment, based on the HIV testing algorithm
9. Owns an iOS or Android mobile phone and able to successfully download mobile apps and send and receive text messages
10. Must not share the mobile phone used for their participation in the study
11. Able to read and write

Exclusion Criteria:

1. Participated in HPTN 113-01
2. Currently participating in another interventional trial of PrEP agents, or prior enrollment in studies of long-acting PrEP, including HPTN 083
3. Plans to move away from the study area within the next year
4. Currently on doxycycline for STI PEP
5. Has ever used CAB-LA or other long-acting PrEP agent
6. Tetracycline allergy
7. Prior diagnosis of HIV infection
8. Reactive HIV rapid test at Screening or reactive HIV Ag/Ab rapid test at Enrollment, regardless of subsequent HIV test results
9. Any other condition that, in the opinion of the Investigator of Record (IoR)/designee, would preclude informed consent, make study participation unsafe, complicate interpretation of study outcome data, or otherwise interfere with achieving the study objectives would make the patient unsuitable for the study or unable/unwilling to comply with the study requirements

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: 3P mHealth package; HIV PrEP, doxy-PEP, 3P mHealth package (3P: MyPrEP + PrEPmate + PrEPsmart tools) to assist with PrEP uptake and adherence decision making, standard-of-care PrEP adherence counseling from qualified study staff, handout about the different PrEP options available at the site	Drug: HIV PrEP - choice of F/TDF, F/TAF, or CAB-LA; Choice of F/TDF, F/TAF, or CAB-LA for HIV prevention; Drug: STI PEP - Doxycycline as Doxy-PEP; Doxycycline as doxy-PEP for STI prevention; Behavioral: 3P mHealth package; Suite of mHealth tools (MyPrEP, PrEPmate, PrEPsmart) to assist with HIV PrEP uptake and adherence decision making; Behavioral: Handout about HIV PrEP options available at the site; Handout about HIV PrEP options available at the site; Behavioral: Standard-of-care HIV PrEP counseling from qualified study staff; Standard-of-care HIV PrEP counseling from qualified study staff
Active Comparator: Standard-of-care services; HIV PrEP, doxy-PEP, standard-of-care PrEP adherence counseling from qualified study staff, handout about the different PrEP options available at the site	Drug: HIV PrEP - choice of F/TDF, F/TAF, or CAB-LA; Choice of F/TDF, F/TAF, or CAB-LA for HIV prevention; Drug: STI PEP - Doxycycline as Doxy-PEP; Doxycycline as doxy-PEP for STI prevention; Behavioral: Handout about HIV PrEP options available at the site; Handout about HIV PrEP options available at the site; Behavioral: Standard-of-care HIV PrEP counseling from qualified study staff; Standard-of-care HIV PrEP counseling from qualified study staff

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To determine the efficacy of the 3P mHealth package on PrEP uptake among participants	PrEP uptake is defined as the proportion of enrolled participants who elect to initiate PrEP (with a documented PrEP dispensation by the site) at any time during the 52 weeks of follow-up. Participants who did not initiate PrEP before loss to follow-up will be classified as non-initiators. PrEP uptake will be assessed at Week 52 for each study arm with 95% confidence limits computed using the binomial distribution. A logistic regression model will be used to compare PrEP uptake between the study arms.	52 weeks
To determine the efficacy of the 3P mHealth package on PrEP adherence among participants	PrEP adherence is assessed at Weeks 20, 36 and 52 through biomedical testing for oral PrEP regimens and documentation of CAB-LA injection for CAB-LA. Adherence measures are described in Section 8.7. Participants on oral PrEP missing an assessment visit and with no PrEP dispensed at their most recent visit will be considered non-adherent. Also, participants who have not yet initiated PrEP at a visit will be considered non-adherent at that visit. The average PrEP adherence at a visit will be computed as the proportion of participants who are determined to be adherent at that visit by study arm. The associated 95% confidence limits will be computed using the binomial distribution. Generalized estimating equations (GEE) with a logit link function will be used to examine differences in adherence proportions between the 3P and Control arms at Weeks 20, 36 and 52, while accounting for potential correlation between PrEP adherence measures over time for each participant.	Weeks 20, 36, and 52
To assess doxycycline PEP uptake and associated factors	doxy-PEP uptake is defined as the proportion of participants dispensed doxy-PEP during the 52 weeks of study follow-up period. doxy-PEP uptake will be computed with 95% confidence limits at Week 52. Multivariable logistic regression models will be used to assess association between doxy-PEP uptake and factors including study group, demographic and behavioral characteristics.	Week 52
To assess doxycycline PEP use and associated factors	doxy-PEP use will be assessed at Weeks 20, 36 and 52. Doxy-PEP use at an assessment visit will be computed as the proportion of participants reporting use following sex acts, reported at that visit. The corresponding 95% confidence limits will be computed based on the binomial distribution. Multivariable GEE models will be used to investigate possible associations between doxy-PEP use and factors including study group, demographic and behavioral characteristics.	Weeks 20, 36, and 52
To assess doxycycline PEP acceptability and associated factors	Descriptive statistics will be used to summarize doxy-PEP acceptability. Multivariable generalized linear models (with a link function that is appropriate to the scale of the measure for doxy-PEP acceptability) will be used to investigate associations between doxy-PEP acceptability and factors including study group, sociodemographic, and behavioral characteristics.	Week 52
To assess the incidence of HIV infections among participants choosing to use CAB-LA	Uptake of CAB-LA is defined as the proportion of participants choosing to initiate CAB-LA with a documented receipt of a CAB-LA injection during the study follow-up period. CAB-LA uptake will be computed with 95% confidence interval. Incidence of HIV infection between the date of CAB-LA initiation and the date of switch to oral PrEP (for participants switching from CAB-LA to oral PrEP) or end of follow-up (for participants staying on CAB-LA from initiation through the end of the follow-up period) will be computed with 95% confidence interval among participants choosing to use CAB-LA.	Week 52

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To determine the acceptability and use of the 3P mHealth package in the intervention arm by site	Descriptive statistics will be used to summarize the acceptability and use of the 3P mHealth package in the intervention arm by site.	Week 52
To compare the frequency, directionality, and reasons for PrEP regimen choice and switching, between arms	Descriptive statistics will be used to summarize the frequency, directionality, and reasons for PrEP regimen choice and switching by arm. Generalized linear models will be used to assess differences in these descriptive summaries between the study arms. Reasons for PrEP regimen choice and switching obtained from qualitative interview data will be listed by arm.	Week 52
To evaluate demographic, behavioral, and attitudinal factors associated with choice of PrEP regimen	Multivariable logistic regression models will be used to separately assess associations between each PrEP regimen choice and demographic, behavioral, and attitudinal factors.	Week 52
To determine the efficacy of the 3P mHealth package on prevention-effective adherence	The proportion of enrolled participants with incident STI infection will be computed with 95% confidence limits at Weeks 20, 36 and 52 by study arm.; The proportion of enrolled participants with incident HIV infection will be computed at Weeks 20, 36 and 52 by study arm.; The proportion of enrolled participants reporting HIV risk based on self-reported sexual behavior and HIV status of sexual partner will be computed at Weeks 20, 36 and 52 by study arm.; The proportion of enrolled participants who are determined to be PrEP adherent and potentially at HIV risk (based on incident STI, self-reported sexual behavior and HIV status of partners) will be computed with 95% confidence limits at Weeks 20, 36 and 52 by study arm. GEE models with a logit link function will be used to compare the proportions between the study arms	Weeks 20, 36, and 52

Collaborators and Investigators

• Sponsor: HIV Prevention Trials Network
• Collaborators: National Institute of Allergy and Infectious Diseases (NIAID); Gilead Sciences; ViiV Healthcare
• Investigators: Study Chair: Susan Buchbinder, MD, San Francisco Department of Public Health and University of California San Francisco; Study Chair: Jorge Gallardo-Cartagena, MD, Centro de Investigaciones Tecnológicas Biomédicas y Medioambientales; Study Chair: Thiago Torres, MD, Instituto Nacional de Infectología Evandro Chagas

Study record dates

Study Major Dates

• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): September 1, 2029
• Study Completion (Estimated): September 1, 2029

Study Registration Dates

• First Submitted: October 7, 2024
• First Submitted That Met QC Criteria: June 15, 2026
• First Posted (Actual): June 22, 2026

Study Record Updates

• Last Update Posted (Actual): June 22, 2026
• Last Update Submitted That Met QC Criteria: June 15, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Post-Exposure Prophylaxis (PEP); Human Immunodeficiency Virus (HIV); Pre-Exposure Prophylaxis (PrEP); Integrated Strategy; Hepatitis B (HBV); Sexually Transmitted Infection (STI); Young Men; Doxycycline for STI Post-Exposure Prophylaxis (Doxy-PEP); Chlamydia Trachomatis (CT); Neisseria Gonorrhea (NG); Mobile Health Tools (mHealth); MyPrEP + PrEPmate + PrEPsmart Tools (3P)
• Additional Relevant MeSH Terms: Blood-Borne Infections; Urogenital Diseases; Genital Diseases; Pathologic Processes; Disease Attributes; Immune System Diseases; Infections; RNA Virus Infections; Virus Diseases; Digestive System Diseases; Liver Diseases; Hepatitis, Viral, Human; Communicable Diseases; Sexually Transmitted Diseases, Viral; Lentivirus Infections; Retroviridae Infections; Immunologic Deficiency Syndromes; DNA Virus Infections; Slow Virus Diseases; Hepadnaviridae Infections; Hepatitis; Pathological Conditions, Signs and Symptoms; HIV Infections; Acquired Immunodeficiency Syndrome; Sexually Transmitted Diseases; Hepatitis B
• Other Study ID Numbers: HPTN 113; UM1AI068619 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: For studies within two years of primary objective(s) publication, de-identified individual participant data that underlie results in a publication, will be provided upon request. For studies more than two years from the primary objective(s) publication, de-identified datasets will be available upon request (Public Use Datasets).
• IPD Sharing Time Frame: Investigators may request de-identified datasets in order to duplicate published results, as required by specific journals. Otherwise, de-identified datasets will be made available upon request, two years following publication of the primary results manuscript.
• IPD Sharing Access Criteria: Researchers may submit a request for access to data that has informed published results, by sending an email to HPTN-Data-Access@scharp.org. To access available de-identified datasets, investigators must complete the request form on the Atlas website. Researchers of approved requests will need to sign an HIV Prevention Trials Network (HPTN) Data Use Agreement before receiving the data and agree to use the provided acknowledgement statement.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: Yes