Predictors of discontinuing injectable cabotegravir/rilpivirine and virologic outcomes after resuming oral antiretroviral therapy.

Objective: Evaluate factors associated with discontinuation of long-acting injectable (LAI) cabotegravir/rilpivirine (CAB/RPV) and describe virologic outcomes in those that returned to oral antiretroviral therapy (ART).

Methods: This is a retrospective cohort study at a single-centre primary care HIV clinic. Included were adults who received at least one injection of LAI CAB/RPV between April 2021 and March 2024. Characteristics were compared between those that continued LAI CAB/RPV and those that discontinued treatment during the study period. HIV viral load (VL) outcomes were evaluated in those that returned to oral ART and included the most recent VL in the range of 1-24 weeks, 24-48 weeks and the most recently documented VL through September 2024.

Results: A total of 92 and 346 patients were included in the discontinuation and continuation cohorts, respectively. Being male sex assigned at birth and having psychiatric disease was associated with continuing LAI CAB/RPV, whereas having active substance use and being on a multi-class regimen prior to initiation of LAI CAB/RPV was associated with discontinuation. In those with VL data after resuming oral ART, the percentage of those with HIV VL <50 copies per mL up to 24 weeks (n = 58) was 91.4%, up to 48 weeks (n = 53) was 90.6%, and using the most recent documented VL (n = 74) was 91.9%.

Conclusions: High viral suppression rates were observed in those that returned to oral therapy after discontinuing LAI CAB/RPV. Individuals with substance use demonstrated a higher rate of LAI discontinuation, despite the potential benefit from LAIs in this population.