393. Long-Acting Injectable Cabotegravir and Rilpivirine in the Aging HIV Population: Insights from the RELATIVITY Cohort

Abstract Background Long-acting injectable cabotegravir and rilpivirine (LAI CAB+RPV) has become a standard treatment option for people living with HIV (PLWH), offering high efficacy, safety, and convenience. However, data from clinical trials and real-world cohorts involving people over 60 - an important and growing population with physiological differences and emerging comorbidities - remain scarce. Virological Efficacy Over Time by Age Group Among PLWH on LAI CAB+RPV. Methods We conducted a multicenter, retro-prospective study within the Spanish RELATIVITY cohort, analyzing virologically suppressed PLWH aged ≥60 years who transitioned to LAI CAB+RPV. We described this population and evaluated factors associated with virological outcomes using Kaplan–Meier analysis and Cox proportional hazards models. Results This substudy included 380 PLWH from 58 Spanish hospitals (11.8% of the RELATIVITY cohort). The median age was 63 years (IQR, 61–67); 78% were male, and 90.3% were Spanish nationals. Comorbidities were present in 79.5% of participants, with dyslipidemia (51.6%), hypertension (36.3%), and osteoporosis (15%) being the most common. The median time on ART prior to switching was 18 years (IQR, 11–25), and the median duration of sustained viral suppression was 11 years (IQR, 6.3–17). The main reasons for switching to LAI CAB+RPV were to improve comfort or quality of life (51.7% in those < 60 years vs. 45.8% in those ≥60 years; p = 0.034) and treatment simplification (23.6% vs. 25.5%; p = 0.436). Virological success exceeded 96.5% across all age groups, with a low virological failure rate observed in the older population (0.8%; p = 0.844). Age was not significantly associated with virological failure in either Kaplan–Meier or Cox proportional hazards analyses (HR, 0.996; 95% CI, 0.962–1.031; p = 0.814). Discontinuation rates for any cause were similar between groups (5.2% vs. 5.8%; p = 0.873). No statistically significant differences were found in adverse event rates (0.8% vs. 1.6%; p = 0.335), including injection site reactions (1.4% vs. 1.3%; p = 0.801). Conclusion In a real-world setting, LAI CAB+RPV is a viable and effective treatment option for people over 60 living with long-standing HIV infection and multiple comorbidities. The regimen demonstrated excellent virological control and was well-tolerated across all age groups. Disclosures All Authors: No reported disclosures