What is PrEP?

PrEP stands for Pre-Exposure Prophylaxis. PrEP is an HIV prevention strategy that uses anti-HIV medications to fight HIV in people who do not have HIV to reduce the risk of getting HIV. HPTN 084-01 is testing the safety, acceptability, and side effects of long-acting injectable cabotegravir for PrEP, which is not currently approved for use among adolescents assigned female at birth. There are currently only two drugs approved for PrEP by the U.S. Food and Drug Administration (FDA) and both are single pills taken as prescribed that contain two anti-HIV drugs: 

  • emtricitabine and tenofovir disoproxil fumarate (TDF/FTC), sold under the brand name Truvada®
  • emtricitabine and tenofovir alafenamide (TAF/FTC), sold under the brand name Descovy®

Truvada (TDF/FTC) is approved for PrEP for all adults and adolescents at risk of HIV. Descovy is approved for HIV prevention in adult and adolescent cisgender men and transgender women who have sex with men but has not been studied in other populations. 

PrEP types

What is Truvada for PrEP?

Truvada is a daily oral pill for PrEP that contains two anti-HIV medications: emtricitabine (FTC) and tenofovir (TDF). Truvada works by preventing HIV from making copies of itself. This means that if you are exposed to HIV and you have been taking Truvada every day, the virus is more likely to die before multiplying in your body. Studies have shown that Truvada reduces the risk of acquiring HIV from sex by over 90 percent when taken as prescribed. Truvada for PrEP is safe. Most people taking Truvada do not have any serious side effects from the medicine. 

For more information about Truvada for PrEP visit  truvada.com. 

What is long-acting cabotegravir for PrEP?

CAB
Photo courtesy of ViiV Healthcare

Long-acting injectable cabotegravir (CAB LA) is a medication for PrEP that is currently being studied in HPTN 083 and HPTN 084 to see if it works to prevent HIV. CAB LA for PrEP is a single injection every eight weeks. Two forms of CAB are being used in HPTN studies: a pill that is taken daily by mouth for five weeks only (known as oral CAB) and a long-acting injectable (CAB LA), received in clinic every eight weeks. Since cabotegravir can remain in the body for up to a year or more in some people, the pill is taken for five weeks first to make sure there are no reactions to cabotegravir before an injection is given. 

Is injectable CAB safe?

Studies conducted so far in adults have shown CAB to be safe. Safety will continue to be assessed among adults in HPTN 083 and HPTN 084 as well as among adolescents in HPTN 083-01 and HPTN 084-01. 

Can injectable CAB protect participants from getting infected with HIV?

Yes. On November 5, 2020, a Data and Safety Monitoring Board (DSMB) reviewed HPTN 084 study data and recommended that the blinded phase of the study be stopped early for successfully meeting its specified objectives. The HPTN 084 study found that a regimen containing CAB LA injected once every eight weeks was superior to daily oral TDF/FTC at preventing HIV acquisition in cisgender women.  “Superior”, in this situation, means that CAB LA worked better than the TDF/FTC. Among the 38 women in the trial who acquired HIV, four were receiving CAB LA and 34 were receiving daily oral TDF/FTC: in other words, approximately 9 times the number of incident HIV infections were in the TDF/FTC arm than in the CAB LA arm. The study sponsor, the U.S. National Institute of Allergy and Infectious Diseases (NIAID), approved the decision to stop the blinded part of the study. More information about HPTN 084 is available at 084life.org or hptn.org/research/studies/hptn084. 

HPTN 083Results from the HPTN 083 study released at the AIDS 2020 virtual conference showed that a PrEP regimen containing CAB LA is superior to (better than) oral Truvada (TDF/FTC) for PrEP in 4,570 cisgender men and transgender women who have sex with men enrolled in HPTN 083. More information about HPTN 083 is available at giveprepashot.org or hptn.org/research/studies/hptn083. 

As a reminder, Truvada (TDF/FTC) is approved by the U.S. Food and Drug Administration (FDA) to treat people with HIV and to prevent people from getting HIV (PrEP). Cabotegravir is not yet approved by the FDA. 

What do the HPTN 083 and HPTN 084 results mean for HPTN 084-01?

We are not changing how we are doing HPTN 084-01 because we still need to see if the CAB LA shots are safe and acceptable in youth. We need to find this out if we want CAB LA shots to be approved for use in youths. So, all participants in HPTN 084-01 will receive CAB LA shots. HPTN 083-01 and HPTN 084-01 will not show us if CAB works as PrEP among adolescents but will show us if CAB LA shots are safe and acceptable in youth.