P-338. Real-World Adherence Patterns and Characteristics of Patients Initiating Injectable Cabotegravir for Pre-exposure Prophylaxis (PrEP) or HIV Treatment

Abstract Background Effective viral control using daily oral antiretroviral therapy (ART) for HIV requires optimal adherence. Injectable cabotegravir/rilpivirine offers less frequent administration with comparable efficacy to oral ART. Injectable cabotegravir for pre-exposure prophylaxis (PrEP) requires less frequent dosing compared to oral PrEP, which may impact adherence. Understanding adherence patterns is crucial for optimizing real-world effectiveness. Methods Adherence was assessed in treatment-naïve patients with an index pharmacy claim from January 2021 through December 2022 for long-acting HIV treatment (patients with ≥1 claim for injectable cabotegravir/rilpivirine) or PrEP (patients with ≥1 claim for injectable cabotegravir). Adherence was defined as initiation and completion of initial and follow-up doses as prescribed. Logistic regression was employed to assess the likelihood of adherence within both treatment cohorts based on certain demographic and clinical characteristics: age, sex, race/ethnicity, geographic region, Charlson comorbidity index, insurance type, and social determinant of health index. Results are presented as odds ratios (OR) with corresponding 95% confidence intervals (CI). Statistical significance was set at p< 0.01. Results We identified 916 PrEP and 1,085 HIV treatment patients. Non-adherence was more prevalent among PrEP vs HIV treatment patients (29% vs 17.4%, p < 0.001). Within the PrEP cohort, individuals residing in the South (OR=0.46, 95% CI: 0.29-0.75, p=0.002) and Midwest (OR=0.55, 95% CI: 0.34-0.91, p=0.018) regions had significantly lower odds (54% and 45%, respectively) of adherence compared to the northeast. There were no statistically significant associations with treatment adherence and other patient characteristics examined in either HIV treatment or PrEP cohort. Conclusion Despite reductions in administration frequency and pill burden with long-acting injectable ART, 29% of injectable PrEP patients have sub-optimal adherence. Our findings highlight the need for targeted interventions and education to support patients receiving long-acting injectable ART for both PrEP and HIV treatment, particularly focusing on regional disparities within PrEP populations. Disclosures Stefanie Pitts, Pharm.D., Accredo: Employment|Accredo: Stocks/Bonds (Public Company) Gail Bridges, PharmD, Accredo Specialty Pharmacy: Employee