Higher levels of use of Truvada (tenofovir disoproxil fumarate/emtricitabine) as pre-exposure prophylaxis (PrEP) in major U.S. cities is independently associated with a declining rate of new HIV diagnoses, after controlling for the rate of viral suppression among people in medical care for the virus, aidsmap reports.

Trevor Hawkins, MD, of Gilead Sciences, which manufactures Truvada, presented findings from a study of 19 so-called fast-track cities (FTCs) in the United States at the 2019 Fast-Track Cities conference in London. The study is an extension of a previous studypresented at the 2018 International AIDS Conference in Amsterdam (AIDS 2018) that looked at PrEP use on a statewide basis.

The study examined the proportion of individuals who were good PrEP candidates according to U.S. guidelines who were diagnosed with HIV in a given year. As a shorthand, the study authors referred to this figure as simply “HIV incidence.” (By the standard definition, incidence is all new cases, whether diagnosed or not.)

In 2012, when Truvada for PrEP was approved, HIV incidence was 6.8% in the FTCs and 4.1% in the United States as a whole. Over the next five years, incidence fell by 8.7% per year in the FTCs, compared with 6.6% per year in the nation as a whole, or by a respective 43.5% and 33.5% during the entire period. In 2017, incidence was 4.4% in the FTCs and 3.4% in the nation as a whole.

Between 2012 and 2017, the proportion of people in medical care for HIV who had a fully suppressed viral load increased from 51% to 61% in FTCs and from 54% to 64% in the nation as a whole.

During this period, the proportion of those at risk for HIV who were taking PrEP rose from 1.5% to 14.7% in the FTCs and from 1.7% to 15.6% in the nation as a whole. The difference between these pairs of rates was not statistically significant, meaning it may have been driven by chance.

The study authors broke down the 25 metropolitan areas that make up the 19 FTCs (some FTCs include more than one metro area) into five quintiles based on PrEP-use rates. In 2017, HIV incidence was 5.4% in the lowest quintile of PrEP use while the incidence was 4.6% in the highest quintile—a 15.6% difference that was statistically significant. The difference remained significant after the investigators adjusted the data to account for differences in viral suppression rates among those in HIV care.

To read the aidsmap article, click here.