How frequently -- and effectively -- is pre-exposure prophylaxis being employed in adults and adolescents in the US who are at risk for HIV infection?
Two new studies presented at the International AIDS Conference in Durban, South Africa, provide new insights into the real-world use of pre-exposure prophylaxis (PrEP) among US patients, both adults and adolescents at risk, infected with human immunodeficiency virus (HIV).
Increased PrEP Use Among US Adults
A nationally representative study assessing PrEP use in the US found that 49,469 adults received a prescription for Truvada (a combination of emtricitabine and tenofovir disoproxil fumarate) for PrEP from January 2013 to December 2015, reported Scott McCallister of Gilead Sciences, Inc., the manufacturer of the drug.
The number of prescriptions increased nationally over time, from 3,746 in 2013 to 14,756 in 2014 to 30,967 in 2015. The de-identified data derive from 82% of retail pharmacies on adults who received a Truvada prescription.
The results also show that the 4 states with the highest number of new HIV cases in the US (California, New York, Texas, and Florida) accounted for 43% of PrEP starts. From 2014 to 2015, PrEP starts increased in the South and Northeast, and decreased in the Midwest and West.
The vast majority of PrEP prescriptions were for males (87.5%), with a mean age of 37.4 years; some 11.5% were for those under age 25.
Those receiving PrEP were about 3 times less likely to be female and twice as likely to be under age 25, compared to HIV-positive individuals.
The authors conclude that despite positive trends in PrEP use, “utilization must increase to ensure lifetime risk seroconversion decreases in areas of high prevalence HIV in the US.”
PrEP Use Among US Adolescents at Risk
An open-label study looked at PrEP use among gay and bisexual male adolescents, ages 15 to 17, in 6 US cities.
Truvada is not currently licensed for PrEP among individuals under age 18, but participants were permitted to autonomously consent to the study, reported Sybil Hosek of the Stroger Hospital of Cook County Health and Hospitals System in Chicago, IL.
Between August 2013 and September 2014, ATN 113 (Project PrEPare) enrolled 78 individuals, mean age 16.5 years. One-third were of mixed race, 29.5% were black, and 20.5% were Latino.
Incident sexually transmitted infections were diagnosed in 12.3% of participants at week 24 and 10.6% at week 48. The HIV seroconversion rate per 100 person-years was 6.41.
The majority of participants reported condom-less sex throughout the study; no significant associations were found between condom-less sex and adherence. Also, the majority achieved protective drug levels during monthly visits, but adherence decreased with quarterly visits.
In conclusion, the authors state: “HIV incidence was still high despite PrEP provision, suggesting high background incidence. Regulatory approvals for youth under 18 years are required to foster support for youth-friendly settings that will optimize PrEP use.
“More work is needed to address traditional adherence barriers, plus stigma-related concerns. Adolescent implementation of PrEP needs developmentally appropriate strategies. Youth need enhanced visit schedules and/or more frequent interactions in-person or via mobile technology. We must be willing to give adolescents the time and attention that they need.”