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Not yet taking people in BrazilPhase 3

Combined HIV prevention medicine and doxycycline after sex to prevent infections in young men

Tests HIV PrEP together with doxycycline after sex in young men.

Plain-language title generated from the registry record
Registry title: Duo: A Phase IIIb Individual-Level Randomized Controlled Trial of an Integrated Strategy

Key facts

Where
Manguinhos, BrazilSee the site
Phase
Phase 3

AI summary: who the study is looking for

From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.

The trial is looking for men aged 18 to 29 who have sex with men, are at risk of HIV, and have no HIV infection. It tests an HIV PrEP and STI PEP strategy.

Age
18 to 29 years
Sex
Men only
Disease stage
No HIV infection at screening and enrolment, with certain HIV risk factors in the past 6 months (such as condomless anal sex with a man, 2 or more male partners, a gonorrhea, chlamydia or syphilis diagnosis, or stimulant use).
Earlier treatment
Not on PrEP in the past 3 months by their own choice. Never used CAB-LA or another long-acting PrEP drug. Not currently on doxycycline for STI PEP.
Biomarker or test result
HIV-negative, based on the HIV testing algorithm.

Main reasons for not taking part

  • Prior diagnosis of HIV infection
  • Reactive HIV test at screening or enrolment
  • Tetracycline allergy
  • Currently in another PrEP drug trial, or earlier in a long-acting PrEP study such as HPTN 083
  • Plans to move away from the study area within the next year

Read by machine on 9 November 2026.

Could this be for you?

Answer for yourself. This is not a decision: only the study team can say whether you can take part.

  • Are you between 18 and 29 years old?

Source: NCT07658976, who can take part

Where in Brazil

  • Instituto de Pesquisa Clinicaq Evandro Chagas CRSManguinhos, BrazilNo longer taking part

Questions to ask the study team

  1. How often do I need to come in, and for how long each time?
  2. Are travel costs paid?
  3. Can I keep my own doctor?
  4. What happens if I want to stop?

Contact the study team: see the registry record → Contacts and Locations

Print a page for my doctor

Trial details

Who runs it
HIV Prevention Trials Network
Trial code
NCT07658976
Record updated
22 June 2026
Original description
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 MenRead full original descriptionShow less

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

Inclusion: 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: Currently participating in another interventional trial of PrEP agents, or prior enrollment in studies of long-acting PrEP, including HPTN 083; Currently on doxycycline for STI PEP; Prior diagnosis of HIV infection; Tetracycline allergy; 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; Participated in HPTN 113-01; Plans to move away from the study area within the next year; Has ever used CAB-LA or other long-acting PrEP agent.

ClinicalTrials.gov NCT07658976