PrEP as bridge to ART highly successful in HIV prevention
SEATTLE — A project integrating time-limited pre-exposure prophylaxis along with ART among high-risk, serodiscordant couples demonstrated an observed HIV incidence of less than 0.5% per year, according to data presented at CROI 2015.
“Developing effective strategies to deliver ART and PrEP to couples is a priority,” Jared Baeten, MD, PhD, professor at the University of Washington, said during his presentation. “Approaches that integrate ART and PrEP may have maximal benefits, since neither alone eliminates HIV risk.”
Baeten and colleagues conducted the Partners Demonstration Project, an open-label, prospective, interventional study conducted at four clinical care sites in Africa. Heterosexual serodiscordant couples were enrolled, and the infected partner received ART regardless of CD4 count, and the uninfected partner received Truvada (tenofovir/emtricitabine, Gilead Sciences) PrEP until the infected partner had been on ART for 6 months, allowing time for the partner to achieve viral suppression. None of the enrolled couples participated in the Partners PrEP study. The couples were followed at 1 month, and then quarterly for up to 24 months.
From November 2012 to August 2014, 1,013 high-risk couples were enrolled. To date, 858 person-years have been accrued, and the uptake of PrEP and ART are high. The expected incidence of HIV in the population was 5.2 per 100 person-years. But there only have been two incident HIV infections observed, resulting in an HIV incidence of 0.2 per 100 person-years. The incidence is a 96% reduction compared with the expected incidence (P < .0001).
The two HIV seroconverters had evidence of limited PrEP use. Both reported breaks in use, and tenofovir was undetectable in plasma samples taken when seroconversion was detected. In addition, the ART use differed for the HIV-positive partner for both.
“Our study differs substantially from randomized trials of PrEP and ART in its open-label, implementation science approach and its focused recruitment of higher-risk couples,” Baeten said. “Our results demonstrate that PrEP as a bridge to ART is not only feasible but highly effective in preventing HIV transmission in this population. Notably, the majority of person-time accrued to date is PrEP-exposed, emphasizing an important PrEP effect for our results.”
Baeten said the project is ongoing, and the ultimate goal is to inform policies regarding ART and PrEP for prevention in couples. In addition, he said the results may speak to the potential for this regimen in other high-risk populations, including men who have sex with men.” – by Emily Shafer
Baeten J. Abstract 24. Presented at: Conference on Retroviruses and Opportunistic Infections; Feb. 23-26, 2015; Seattle.
Disclosure: Baeten reports no relevant financial disclosures.