HPTN 083

A Phase 2b/3 Double Blind Safety and Efficacy Study of Injectable Cabotegravir Compared to Daily Oral Tenofovir Disoproxil Fumarate/Emtricitabine (TDF/FTC), for Pre-Exposure Prophylaxis in HIV-Uninfected Cisgender Men and Transgender Women who have Sex with Men

Study Summary
Study Documents - Study Details* - Key Study Personnel* - Study SitesPublications
*Authenticated users only (create your account here)

*** 7 July 2020 ***

HPTN 083 Study Demonstrates Superiority of Cabotegravir for the Prevention of HIV



What is HPTN 083?

HPTN 083 is the first study to compare the efficacy of CAB LA to daily oral TDF/FTC for HIV PrEP. HPTN 083 enrolled 4,570 cisgender men who have sex with men (MSM) and transgender women (TGW) who have sex with men at 43 sites in Argentina, Brazil, Peru, United States, South Africa, Thailand and Vietnam.

Why is HPTN 083 important?

For many people, taking a daily pill can be challenging. The development of safe and effective long acting alternative agents for HIV PrEP would increase HIV prevention choices and help those who find taking a daily pill challenging. Some people also may find periodic injections to be a more discreet form of HIV PrEP than daily pills and may prefer CAB LA for that reason.

What happened during the study?

Participants were assigned randomly (by chance) to either the CAB or oral TDF/FTC group. Neither the participants nor the study team knows who was in which group. Participants in each group received both injections and oral tablets – each participant received one active drug and one placebo (no active drug) in order to maintain the blinded nature of the study. Participants were randomized to one of two study arms and included three steps: Step 1 consisted of 5 weeks of daily oral CAB and a TDF/FTC placebo or 5 weeks of daily oral TDF/FTC and an oral CAB placebo; Step 2 consisted of 148 weeks of intramuscular CAB LA 600 mg every 8 weeks plus daily oral TDF/FTC placebo or 148 weeks of daily oral TDF/FTC plus an intramuscular CAB LA placebo every 8 weeks ; and Step 3 consisted of an open-label daily oral TDF/FTC for 48 weeks after participants completed Step 2.

What were the results of the study?

On May 14, 2020 a Data and Safety Monitoring Board (DSMB) reviewed HPTN 083 study data and recommended that the blinded part of the study be stopped early for successfully meeting its specified objectives. The study results showed that CAB LA, administered every eight weeks, provided high efficacy compared to TDF/FTC. A total of 50 incident HIV infections occurred in HPTN 083, with 38 incident HIV infections in the TDF/FTC arm (incidence rate 1.21%) and 12 incident HIV infections in the CAB arm (incidence rate 0.38%): in other words, approximately three times the number of incident HIV infections were in the TDF/FTC arm than in the CAB 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.

After a more extensive analysis of the interim study data, the regimen containing CAB LA was found to be statistically superior to daily oral TDF/FTC for PrEP among the cisgender men and transgender women who have sex with men enrolled in HPTN 083. A total of 52 incident HIV infections occurred, with 13 incident infections in the CAB arm (incidence rate 0.41%) and 39 incident infections in the TDF/FTC arm (incidence rate 1.22%). The hazard ratio for the CAB versus TDF/FTC arms is 0.34 (95% CI 0.18-0.62), corresponding to a 66% reduction in incident HIV infections in study participants given CAB compared to TDF/FTC. These results were presented at AIDS 2020.


HPTN 083 schema


Study Documents

HPTN 083 Study Schema

HPTN 083 Version 3.0


HPTN 083 Version 2.0


HPTN 083 Version 1.0




Community Presentations for HPTN 083 Results (May 2020)