Real-world data on long-acting intramuscular maintenance therapy with cabotegravir and rilpivirine mirror Phase 3 results

Introduction: Cabotegravir, an integrase strand transfer inhibitor, and rilpivirine, an NNRTI, constitute the first long-acting (LA), injectable, two-drug ART regimen approved for the maintenance of virological suppression in persons living with HIV-1 (PLHIV). The aim of this study was to assess clinical effectiveness and tolerability of LA cabotegravir/rilpivirine in a real-world setting. Patients and methods: We conducted a retrospective, single centre study, including all PLHIV receiving LA cabotegravir/rilpivirine as standard-of-care in our tertiary centre even if initiated in clinical trials. Results: Between 2014 and 2022, 126 PLHIV initiated LA cabotegravir/rilpivirine. All were ART-experienced, and 98.4% had a viral load (VL) of <50 copies/mL before LA cabotegravir/rilpivirine initiation. Median BMI at cabotegravir/rilpivirine initiation was 24 IQR (23-28). During a median follow-up of 9 months IQR (7-24), 27 patients discontinued cabotegravir/rilpivirine because of virological failure, 6 for adverse events, 11 for personal reasons unrelated to treatment tolerance and 5 for other reasons. Virological failure was not associated with a higher BMI, nor with weight gain during LA intramuscular (IM) cabotegravir/rilpivirine treatment, inadequate cabotegravir and rilpivirine concentrations, VL blips or the use of oral lead-in (OLI) or not. No drug resistance-associated mutation emerged. Adverse events leading to treatment interruption were injection-site pain (n = 3) and neuropsychological side effects (n = 3). A correlation between BMI and both cabotegravir and rilpivirine concentrations at 1 month post-initiation of LA-IM cabotegravir/rilpivirine was observed, with no impact of OLI. Conclusions: Data from this real-world cohort of PLHIV who received cabotegravir/rilpivirine LA injections suggest that this regimen is effective and well tolerated. Virological failures were not associated with the acquisition of resistance mutations.