Anti-HIV drug PrEP proves safety in gay and bisexual adolescents

A new study has found that pre-exposure prophylaxis (PrEP) drugs such as Gilead's Truvada (emtricitabine/tenofovir disoproxil fumarate), which pre-emptively protects against the human immunodeficiency virus (HIV), is safe to be used by gay and bisexual adolescent men. This follows the treatment’s proven efficacy and safety in adult patients, where it was found to reduce the risk of infection by more than 90%, leading to its approval by the FDA in 2012.

The study examined the effects of the drug in a diverse group of 78 high-risk gay and bisexual men aged between 15 and 17 in the US, all of whom were HIV negative at the beginning of the trial. As part of the study, each participant was given daily doses of PrEP and a counselling session on the dangers and risk of HIV.

Forty-seven participants completed the study, and it was found that the HIV transmission rate in the group was 6.4% - twice as high as rates among 18 to 22 year olds. Lead author Sybil Hosek, a clinical psychologist and HIV researcher at Cook County Health and Hospitals System’s Stroger Hospital in Chicago, noted that this rate could be due to poor adherence – in the first 12 weeks of the study, 95% of participants had detectable levels of the drug in their blood, whereas this dropped to 15% after 48 weeks. "I shudder to think what the (HIV infection) rate would be if we didn’t offer PrEP," Hosek remarked.

The drug was well tolerated, with only three adverse events reported that could possibly related to its use. There was also no increase in risky sexual behaviour during the trial.

Three of the participants did become infected with HIV, but blood samples suggested that these men were not taking the necessary dosage when they contracted the virus.

While the results are very promising, Dr Renata Arrington-Sanders of John Hopkins University wrote: "This work suggests that adolescents may require additional visits than what is currently recommended by national guidelines and suggests a need for multiple team members to address structural barriers to accessing PrEP, assist with youths’ interpretation of HIV risk, and support self-efficacy to swallow and adhere to medications."

Hosek agreed with Arrington-Sanders, adding: "Clinicians should not be afraid to see adolescents more frequently, maintain a connection with the adolescents and keep them engaged."