1584. CARISEL A Hybrid III Implementation Effectiveness Study of implementation of Cabotegravir plus Rilpivirine Long Acting (CAB+RPV LA) in EU Health Care Settings Key Clinical and Implementation Outcomes by Implementation Arm

Abstract Background Cabotegravir + Rilpivirine Long Acting (CAB+RPV LA) every 2 months is a recommended regimen in European and US treatment guidelines for PLWH with virological suppression no known resistance to CAB or RPV. CARISEL, an implementation study, the first study where all participants switched from standard oral therapy monthly CAB+RPV. Key clinical secondary endpoints are reported. Methods This single arm enrolled virologically-suppressed receive CAB+RPV LA 2-monthly at 18 clinics 5 EU countries, conducted Sept 2020-Feb 2022. Clinics prior experience were preferentially selected. Sites randomized (Arm-S) enhanced (Arm-E) which included additional strategies. Proportion of plasma HIV-1 RNA ≥50c/mL < 50c/mL Month 12 (FDA Snapshot algorithm, ITT-E) Adverse events, COVID-related clinic visit length, safety analyzed by arm. Results 72% (13/18) had start. 430 treated 25% female, 18% black, mean baseline age 44 yrs (30% > 50 years). At 12, 87% maintained virologic each (Table 1) 1 participant (1/430; 0.23%) Arm-E experienced confirmed failure. Grade 1–2 AEs reported Arm-E:99% vs Arm-S: 97%; 3–4 drug-related Arm-E: 4%, 8%. ISRs 86% participants; 98% mild moderate, median duration 3 days low proportion discontinued due ISR (6%). Total time decreased more than Arm-S; length varied country 2). COVID was diagnosed 16% participants. COVID-19 related protocol deviations 3% There discontinuations snapshot failures COVID-19. Conclusion Regardless arm, highly effective well tolerated, consistent outcomes Phase program. Clinic lengths over time. did not lead disruption discontinuation. Disclosures Stephane De Wit, PhD, AstraZeneca: Grant/Research Support Fabrice Bonnet, Gilead: Support|Gilead: Honoraria|MSD: Support|MSD: Honoraria|ViiV Healthcare: Support|ViiV Honoraria Rebecca DeMoor, M.S., GlaxoSmithKline: Employee Gilda Bontempo, MD, ViiV Employee|ViiV Stocks/Bonds Christine Latham, MS, Martin Gill, BSc, Monica Hadi, Evidera: Savita Bakhshi Anand, Cassidy Gutner, Mounir Ait-Khaled, Stocks/Bonds|ViiV Jean A. van Wyk, MB,ChB; MFPM, Healthcare Limited: I am employee Healthcare|ViiV Maggie Czarnogorski, MD MPH, Stocks/Bonds.