Pre-Exposure Prophylaxis to Prevent HIV-1 Acquisition Within HIV-1 Discordant Couples

HIV-1 uninfected individuals within HIV-1 discordant partnerships are at high-risk for HIV-acquisition. The majority of HIV-1 transmissions to adults in Africa occur within stable, HIV-1 discordant couples.

Pre-exposure chemoprophylaxis, in which an HIV-1 uninfected individual at high risk for contracting HIV-1 takes antiretroviral medications to maintain blood and genital drug levels sufficient to prevent HIV-1 acquisition, has been proposed as a potential HIV-1 prevention strategy.

This study was a randomized, blinded, placebo-controlled trial to demonstrate if pre-exposure prophylaxis decreases HIV-1 acquisition among HIV-1 uninfected individuals within HIV-1 discordant couples. The HIV-1 uninfected partner was randomized in a 1:1:1 ratio to one of three arms: once daily Tenofovir Disoproxil Fumarate (TDF), Emtricitabine/Tenofovir Disoproxil Fumarate (FTC/TDF) or Placebo.

Couples were followed up to 36 months; the HIV uninfected partner attended monthly visits and the HIV infected partner quarterly visits. All participants received a comprehensive package of HIV prevention services including individual and couples counseling, free condoms, and male circumcision referrals.

Participants who seroconverted during follow-up stopped the study drug but continued with follow-up.

Inclusion criteria

for HIV-1 uninfected partner:

• Partner within an HIV-1 discordant heterosexual relationship
• One partner meets study eligibility for HIV-1 uninfected study participant and the other partner meets study eligibility criteria for HIV-1 infected participant
• Plan to remain in the relationship for the duration of the study period
• Adequate renal, hepatic & hematologic function
• Negative Hepatitis B surface antigen test
• Willing and able to provide written informed consent & locator information

Exclusion criteria

for HIV-1 uninfected partner:

• Current pregnancy, or planning to become pregnant during the study period
• Currently breastfeeding
• Concurrent enrollment in another HIV-1 vaccine or prevention trial
• Receiving ongoing antiretroviral therapy
• Repeated positive urine dipstick tests for glycosuria or proteinuria
• Active and serious infections
• History of pathological bone fractures not related to trauma

Inclusion criteria

for HIV-1 infected partner:

• Partner within an HIV-1 discordant heterosexual relationship
• One partner meets study eligibility for HIV-1 uninfected study participant and the other partner meets study eligibility criteria for HIV-1 infected participant
• HIV-1 infected based on positive EIA
• No history of any clinical AIDS-defining diagnoses
• Plan to remain in the relationship for the duration of the study period
• Willing and able to provide written informed consent & locator information

Exclusion criteria

for HIV-1 infected partner:

• Current use of antiretroviral therapy
• Concurrent enrollment in another HIV-1 treatment trial