A NIH network study finds that pre-exposure prophylaxis, approved for daily use in adults, can also reduce chances of HIV infection in young male adolescents.
Young individuals between the ages of 10 and 24 years as well as adolescents between the ages of 10 and 19 years, continue to be disproportionately affected by HIV. In fact, according to AVERT, the number of HIV-positive adolescents rose by 28% between 2005 and 2015; young men who have sex with men are at highest risk for infection.
Currently, the pre-exposure prophylaxis (PrEP) medication Truvada, which is a combination of tenofovir and emtricitabine, is available for adults who are at high risk of HIV infection, but it has yet to be approved in this key population. However, new research coming in from the National Institutes of Health may change that.
“Several studies have shown that daily oral PrEP is effective in preventing HIV among people at high risk of becoming infected, but none of them included adolescents under age 18,” study author Bill Kapogiannis, MD, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)’s Maternal and Pediatric Infectious Diseases Branch said. “Our study suggests that this therapy can safely reduce HIV risk for those under 18.”
The Adolescent Medicine Trials Network for HIV/AIDS Interventions, funded by the NICHD, conducted the study and enrolled 72 male participants between the ages of 15 to 17, who were not infected with the virus at time of enrollment. All participants were considered at-risk due to engagement in risky behaviors, such as having sexual intercourse without protection with a male partner who was either HIV-positive or whose status was unknown, having at least 3 male partners, or having a sexually transmitted disease (STD) other than HIV. The researchers excluded participants who had poor kidney function or a history of bone fractures, “because the drug combination may sometimes stress the kidneys and cause bone loss.”
Over the course of the study, the participants were tested for the virus as well as other STDs, and received counseling and interventions to educate them on risky behaviors that put them at increased risk of infection and how to avoid them.
The participants received oral TDF/FTC [Truvada] daily, for 48 weeks. As the researchers continued to test the participants, it became clear that the longer the study went on, the more participants were not adhering to the regimen. The researchers noted a decline in “levels of the drug sufficient to prevent HIV infection” in the participants. Sufficient drug levels were noted in 54% of participants at week 4 of the study, 49% at week 12, 28% at week 24, and 22% at week 48.
When asked why they were not taking their medications, the majority of the participants gave a reason associated with a fear of stigma: “others will see me taking pills and think I am HIV-positive.” According to the press release, additional reasons for skipping doses included the following:
For the most part, TDF/FTC was well-tolerated in the participants; none of the participants experienced adverse effects on their kidneys or bones. Three of the participants became infected with the virus during the study, all of whom “had no detectable blood levels of TDF/FTC at the visit before their HIV infection was first diagnosed.” Meaning that, most likely, the participants were not taking the medication on a daily basis or they were missing doses entirely.
Because of the lack of adverse health effects experienced by the participants, the authors concluded that the study findings indicate “that the drug is safe for males under age 19.” Furthermore, the lack of infection in the participants who did have appropriate levels of the drug in their blood prove consistent with previous studies conducted with adults; this suggests that “the drug can be effective in this population when taken appropriately.”
The authors called for more contact between this population and clinical staff during therapy as well as better strategies to address the tendency of younger individuals to skip their medication.
The study was funded by the NICHD, the National Institute on Drug Abuse, and the National Institute of Mental Health and was published in JAMA Pediatrics.