The HPTN 083 primary paper and accompanying editorial by Quarraisha Abdool-Karim have been published in The New England Journal of Medicine. The study demonstrated long-acting injectable cabotegravir lowered HIV incidence among cisgender men and transgender women who have sex with men.
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.