Treatment Patterns and Predictors of Adherence in HIV Patients Receiving Single- or Multiple-Tablet Darunavir, Cobicistat, Emtricitabine, and Tenofovir Alafenamide

PURPOSE: Darunavir, cobicistat, emtricitabine, and tenofovir alafenamide can be used as a single-tablet regimen (STR, DRV/c/FTC/TAF) or multiple-tablet regimen (MTR, DRV/c+FTC/TAF) to treat patients with human immunodeficiency virus (HIV). This study described treatment patterns and predictors of adherence among patients with HIV initiated on DRV/c/FTC/TAF or DRV/c+FTC/TAF. PATIENTS AND METHODS: A retrospective longitudinal study was conducted using linked claims and electronic medical records from Decision Resources Group’s Real World Data Repository (7/17/2017–6/1/2019). Treatment-naïve and treatment-experienced virologically suppressed adults with HIV-1 prescribed DRV/c/FTC/TAF or DRV/c+FTC/TAF (index date) were included. Six-month persistence (no treatment gaps >60 and >90 days) and adherence (proportion of days covered [PDC]) to the index regimen were evaluated among patients with ≥6 months of observation post-index. Predictors of low adherence (PDC<80%) were evaluated using a logistic regression model. RESULTS: Among 2633 eligible patients (49.5 years old, 29% female, 37% African American/Black), 12% were treatment-naïve pre-index and 88% switched from a previous antiretroviral therapy; 84% initiated DRV/c/FTC/TAF and 16% initiated DRV/c+FTC/TAF. Among 822 DRV/c/FTC/TAF patients with ≥6 months of observation post-index, 80% and 86% had no >60- and >90-day gaps in DRV/c/FTC/TAF coverage, respectively, while among 204 DRV/c+FTC/TAF patients with ≥6 months of observation post-index, 69% and 75% had no >60- and >90-day gaps in DRV/c+FTC/TAF coverage, respectively. Mean (median) PDC for the index regimen was 81% (93%) for patients treated with DRV/c/FTC/TAF and 73% (83%) for patients treated with DRV/c+FTC/TAF. Predictors of low adherence included younger age (odds ratio [OR]=2.36, p=0.017), higher Quan-Charlson comorbidity index (OR=1.32, p=0.012), use of MTR regimen at index (OR=1.69, p=0.022), and prior low adherence (OR=2.56, p<0.001). CONCLUSION: Among patients initiating a DRV/c-based regimen, those initiating STR had higher 6-month adherence/persistence than those initiating MTR, highlighting the potential benefits of the STR formulation, particularly among younger patients with multiple comorbidities and prior low adherence.