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NCT Number: NCT07658976

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

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

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Key information

Conditions

HIV Infection Acquired Immunodeficiency Syndrome Blood-Borne Infections Communicable Diseases DNA Virus Infections Digestive System Diseases Disease Attributes Genital Diseases HIV Infections Hepadnaviridae Infections Hepatitis Hepatitis B Hepatitis, Viral, Human Immune System Diseases Immunologic Deficiency Syndromes Infections Lentivirus Infections Liver Diseases Pathologic Processes Pathological Conditions, Signs and Symptoms RNA Virus Infections Retroviridae Infections Sexually Transmitted Diseases Sexually Transmitted Diseases, Viral Sexually Transmitted Infection Slow Virus Diseases Urogenital Diseases Virus Diseases

Age range

18 year–29 year

Sex eligibility

Male

Study type

Interventional

Phase

Phase 3

Primary location

Fundacion Huesped CRS, Buenos Aires, Argentina

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About this study

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).

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Men ages 18 - 29 years
  • Men who are in communities most affected by the HIV epidemic
  • Willing and able to provide informed consent
  • Reports having anal sex with men in the last 6 months
  • Have certain risk factors for HIV acquisition, defined as any of the following in the past 6 months:
  • 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
  • Reporting 2 or more male partners, regardless of condom use
  • Reporting gonorrhea, chlamydia, or syphilis diagnosis
  • Any stimulant use (e.g., cocaine, amphetamines)
  • Not on PrEP within the past 3 months due to participant choice
  • Interested in learning more about PrEP or starting PrEP
  • No evidence of HIV infection at Screening and Enrollment, based on the HIV testing algorithm
  • Owns an iOS or Android mobile phone and able to successfully download mobile apps and send and receive text messages
  • Must not share the mobile phone used for their participation in the study
  • Able to read and write

Exclusion criteria

  • Participated in HPTN 113-01
  • Currently participating in another interventional trial of PrEP agents, or prior enrollment in studies of long-acting PrEP, including HPTN 083
  • Plans to move away from the study area within the next year
  • Currently on doxycycline for STI PEP
  • Has ever used CAB-LA or other long-acting PrEP agent
  • Tetracycline allergy
  • Prior diagnosis of HIV infection
  • Reactive HIV rapid test at Screening or reactive HIV Ag/Ab rapid test at Enrollment, regardless of subsequent HIV test results
  • 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

Treatment and study plan

HIV PrEP - choice of F/TDF, F/TAF, or CAB-LA

Drug

Choice of F/TDF, F/TAF, or CAB-LA for HIV prevention

STI PEP - Doxycycline as Doxy-PEP

Drug

Doxycycline as doxy-PEP for STI prevention

3P mHealth package

Behavioral

Suite of mHealth tools (MyPrEP, PrEPmate, PrEPsmart) to assist with HIV PrEP uptake and adherence decision making

Handout about HIV PrEP options available at the site

Behavioral

Handout about HIV PrEP options available at the site

Standard-of-care HIV PrEP counseling from qualified study staff

Behavioral

Standard-of-care HIV PrEP counseling from qualified study staff

Primary outcomes

  1. To determine the efficacy of the 3P mHealth package on PrEP uptake among participants

    Time frame: 52 weeks

    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.

  2. To determine the efficacy of the 3P mHealth package on PrEP adherence among participants

    Time frame: Weeks 20, 36, and 52

    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.

  3. To assess doxycycline PEP uptake and associated factors

    Time frame: Week 52

    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.

  4. To assess doxycycline PEP use and associated factors

    Time frame: Weeks 20, 36, and 52

    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.

  5. To assess doxycycline PEP acceptability and associated factors

    Time frame: Week 52

    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.

  6. To assess the incidence of HIV infections among participants choosing to use CAB-LA

    Time frame: Week 52

    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.

Secondary outcomes

  1. To determine the acceptability and use of the 3P mHealth package in the intervention arm by site

    Time frame: Week 52

    Descriptive statistics will be used to summarize the acceptability and use of the 3P mHealth package in the intervention arm by site.

  2. To compare the frequency, directionality, and reasons for PrEP regimen choice and switching, between arms

    Time frame: Week 52

    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.

  3. To evaluate demographic, behavioral, and attitudinal factors associated with choice of PrEP regimen

    Time frame: Week 52

    Multivariable logistic regression models will be used to separately assess associations between each PrEP regimen choice and demographic, behavioral, and attitudinal factors.

  4. To determine the efficacy of the 3P mHealth package on prevention-effective adherence

    Time frame: Weeks 20, 36, and 52

    • 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

Study contacts

Contact information is provided by the study sponsor or research team.

Kailazarid Gomez-Feliciano, MPM

CONTACT

[email protected]

919-321-3486

Michelle Robinson

CONTACT

[email protected]

919-321-3585

Sponsors and collaborators

Lead sponsor

HIV Prevention Trials Network

Network

Collaborators

  • Gilead Sciences
  • National Institute of Allergy and Infectious Diseases (NIAID)
  • ViiV Healthcare

Registry information

Official study title

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

Important dates

Study start
2026
Primary completion
2029
Study completion
2029
First posted
Jun 22, 2026
Registry last updated
Jun 22, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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