Combining prevention, treatment cuts HIV transmission
the Clinical Advisor take:
A combination of HIV prevention and treatment reduced expected transmission between heterosexual couples by 96%, according to study results presented at the 2015 Conference on Retroviruses and Opportunistic Infections in Seattle.
The couples each had one partner who was HIV-positive and another who was HIV-negative. The HIV-negative partners were treated with oral pre-exposure prophylaxis (PrEP) until (and sometimes after) their HIV-positive partner began anti-retroviral therapy (ART).
In an earlier trial, called Partners PrEP, the researchers demonstrated that HIV-negative people who were treated with prophylaxis via a daily oral pill had a decreased rate of transmission from their HIV-positive partner.
Another trial, the HPTN 052 study, showed that treating the HIV-positive partner with ART significantly reduces the risk of transmission to their HIV-negative partner. However, those who are HIV-positive are often not eligible or not willing to begin treatment; additionally, the prevention benefit of ART does not begin until the person is treated for 6 months.
For this trial, called Partners PrEP, the researchers hypothesized that adding the PrEP component to ART could help reduce the risk of transmission even further than either one alone.
The study did not use a control group because the researchers deemed it unethical. Instead, outcomes were compared with a model developed using the placebo group from the earlier Partners PrEP trial.
Although the study is only halfway complete, the results thus far are encouraging. The researchers have data on approximately 858 person-years of follow up (42% of what is expected). In the placebo model, the expected number of new HIV infections would be 39.7. Among the study participants, there have only been two new cases of HIV, and in both cases, the partners reported breaks in adherence to PrEP.
For HIV-negative people with HIV-positive partners, prevention with treatment reduces transmission.
SEATTLE -- A combination of HIV prevention and treatment almost completely eliminated viral transmission in heterosexual couples in which only one partner had the disease, a researcher reported.
In early results from an open-label study, the combination reduced expected transmissions between partners by 96%, according to Jared Baeten, MD, of the University of Washington in Seattle.
The finding appears to validate the idea of giving the HIV-negative partner oral pre-exposure prophylaxis (PrEP) as a "bridge" until or even after the infected partner begins full-scale anti-retroviral therapy (ART), Baeten said here at the 2015 Conference on Retroviruses and Opportunistic Infections.