Cabotegravir and Rilpivirine concentrations and HIV-1 RNA suppression in genital fluids and rectum in people with HIV on long-acting intramuscular Cabotegravir plus Rilpivirine antiretroviral therapy

This study examined cabotegravir (CAB) and rilpivirine (RPV) distribution and HIV suppression in genital and rectal compartments after switching to long-acting intramuscular CAB+RPV administered every two months. At month 4, drug concentrations were measured in blood plasma, seminal plasma (SP), rectal tissue (RT), and cervicovaginal fluid (CVF). Thirty-one participants (16 cisgender men, 15 cisgender women) were included. CAB and RPV exhibited different distributions between compartments. Unbound CAB exceeded the EC50 in SP, RT and CVF while unbound RPV exceeded the EC50 in RT and CVF but not in SP. All participants maintained HIV-1 RNA <20 copies/mL in all matrices. Clinical Trial Registration: EudraCT Number: 2021-006779-41