HPTN 083 Research Study

What is the research?

HIV Prevention Trials Network (HPTN) 083 is a randomized, active-controlled, double-blind clinical trial that began in December 2016. The study has compared the safety and efficacy of two drugs for use as pre-exposure prophylaxis (PrEP) among a population at increased risk of HIV infection.

  • Study population: 4,570 cisgender men and transgender women who have sex with men, recruited from Argentina, Brazil, Peru, United States, South Africa, Thailand, and Vietnam.
  • Study drugs: Standard-of-care PrEP agent Truvada® (brand name for a formulation combining tenofovir disoproxil fumarate/emtricitabine [TDF/FTC]) compared to a PrEP regimen of long-acting injectable cabotegravir (CAB).
  • Study schema (from hptn.org):

In May 2020, the U.S. National Institute of Allergy and Infectious Disease (NIAID) decided to end the blinded, randomized portion of the study two years ahead of schedule and recommended immediate dissemination of results. This was because the study successfully established that CAB is an effective alternative to Truvada® for PrEP among cisgender men and transgender women who have sex with men. A separate trial comparing the efficacy and safety of the same two drugs with cisgender women in Sub-Saharan Africa (HPTN 084) is ongoing.

What do the results mean?

When the rates of HIV infection for participants who received CAB were compared to those of participants who received daily oral Truvada®, CAB users were found to acquire HIV at rates lower than Truvada® users. CAB was found to be statistically superior to oral Truvada®, meaning that CAB was able to protect more people against acquiring HIV during the study, and that this difference likely cannot be explained by random chance.

Importantly, the interpretation of these data is not that Truvada® is unsafe or ineffective. Truvada®, if taken as directed, is a highly effective option for PrEP, suggesting that the efficacy of the CAB regimen is extremely high.

What does this mean for the future of PrEP?

Cabotegravir as a form of injectable PrEP has the potential to increase uptake and adherence by increasing the choices individuals have for a PrEP medication that fits their needs and lifestyle. However, to ensure that HIV disparities narrow and not widen as a result of cabotegravir’s introduction, policymakers and other groups must consider key determinants that may influence the drug’s accessibility and acceptability.

How can I learn more?

View the following resources for more information about HPTN 083: