Cabotegravir Maintains Protective Efficacy in the Setting of Bacterial STIs: A Secondary Analysis of HPTN 083
Meredith E Clement, Brett Hanscom, Daniel Haines, Jose A Bazan, Nuntisa Chotirosniramit, Ryan Kofron, Sharon Mannheimer, Kenneth H Mayer, Mayara Secco Torres Silva, Lydia Soto-Torres, Alex R Rinehart, James F Rooney, A Jennings, K Gomez-Feliciano, Marybeth McCauley, Beatriz Grinsztejn, Raphael J Landovitz, , Suwat Chariyalertsak, Eileen F Dunne, Nittaya Phanuphak, Tran Viet Ha, Omar Sued, Marcelo H Losso, Esper G Kailas, Jose Valdez Ramalho, Madruga, Breno Riegel Santos, Beatriz Grinsztejn, Juan Carlos Hinojosa Boyer, Javier Antonio Valencia, Huamani, Jorge A Gallardo-Cartagena, Pedro Gonzales, Robinson Cabello, Keren Middelkoop, E Turner Overton, Temitope Oyedele, Albert Liu, Jessica Justman, Christopher Hurt, Daniel Reirden, Carl Fichtenbaum, Christopher Hall, Kenneth Mayer, Manya Magnus, Cornelius van Dam, Julie Franks, Colleen Kelley, Roberto C Arduino, Anne Rompalo, Shobha Swaminathan, Sue Ellen Abdalian, Hong Van Tieu, Jose Bazan, Ian Frank, Carlos del Rio, Aditya Gaur, Raphael J Landovitz, Jesse Clark, Richard Novak, Rachel Presti, Roy (Trip) GulickAbstract
Background
Sexually transmitted infections (STIs) have been shown to facilitate HIV transmission and acquisition. HPTN 083, a global clinical trial, demonstrated superiority of long-acting cabotegravir (CAB-LA) versus daily oral tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) for HIV prevention among transgender women and cisgender men who have sex with men. This analysis assessed whether CAB-LA maintained protective efficacy when bacterial STIs (syphilis, rectal/urethral gonorrhea and chlamydia) were present.
Methods
STI events per 100 person-years (PY) were calculated, including by subgroups (age, race/ethnicity, gender, education, treatment arm, drug use, alcohol use, region/country, condom usage, partner number, marital status, baseline STI). Association between baseline factors and STI incidence was modeled using Poisson regression. Cox proportional hazards modeling with STI status as a time-varying covariate was used to evaluate potential interactions between STI status and the relative efficacy of CAB-LA vs. TDF/FTC.
Findings
Among 3,859 participants, overall STI incidence rate was 50.7 infections/100PY. STIs were diagnosed in 1,562 (40.5%) participants; 79% of STIs occurred in 25% of the participants. STI incidence was not different by PrEP arm. In the final multivariable model, age, region, race, education level, marital status, and baseline STI were associated with incident STI (p<0.05). HIV incidence was lower with CAB-LA vs. TDF/FTC with or without STIs (hazard ratios 0.37 and 0.31, respectively), with no significant interaction between STIs and the HR for HIV incidence (p = 0.75).
Conclusion
In a large PrEP trial with high STI incidence, CAB-LA maintained robust protective efficacy relative to TDF/FTC in the setting of bacterial STIs.