Introduction: Alirocumab is a proprotein convertase subtilisin/ kexin type 9 (PCSK9) inhibitor approved as an adjunct to diet and maximally tolerated statin therapy for treatment of adults with heterozygous familial hypercholesterolemia (HeFH) or clinical atherosclerotic cardiovascular disease who require additional lowering of LDL-cholesterol. Barriers to possession, including therapy cost and cost-sharing implications, may contribute to low utilization of this therapy.
Objective: To explore differences in demographic and clinical characteristics between patients with prior authorization (PA) approvals or denials for alirocumab as evidenced through filled alirocumab prescription claims.
Methods: A retrospective claims-based database analysis of patients with a Medicare Advantage Prescription Drug (MAPD) plan was conducted to identify patients with evidence of a PA approval for alirocumab. Among the group of patients with a PA for alirocumab, the pharmacy claims database was searched for evidence of a corresponding prescription claim within 30 days following the first PA request (index date). The analysis was stratified by evidence of Federal low income subsidy (LIS) support, a program that provides extra assistance with prescription drug costs for eligible individuals whose income and resources are limited, and/ or dual eligibility (DE) status, eligible for Medicare and Medicaid, (LIS/DE) at index.
Results: A total of 2,098 MAPD patients meeting study inclusion/exclusion criteria and with a PA for alirocumab were identified between March 1, 2016 and February 28, 2017. Non-LIS/DE patients comprised approximately 82% of the eligible population (n=1,730). There were several notable differences in baseline demographics between the non-LIS/DE vs. the LIS/DE cohorts with an approved PA claim, including Deyo-Charlson Comorbidity Index (2.2 vs. 3.0), prevalence of diabetes mellitus (39.2% vs. 54.7%), and prevalence of HeFH (11.8% vs. 15.6%). While the percentage of patients with an approved PA was similar between the LIS/DE and non-LIS/DE cohorts, 88.9% and 91.2%, respectively, substantially more patients in the LIS/DE cohort had evidence of alirocumab possession based on a paid claim (60.6%) vs. those in the non-LIS/DE cohort (17.3%).
Conclusion: Although a high percentage of MAPD patients had evidence of an approved PA, there were notable differences in clinical and demographic characteristics between those with and without LIS/ DE status. Further, the proportion of patients with an approved PA and a paid prescription claim differed markedly amongst MAPD patients with and without LIS/DE status, suggesting further research is needed to understand potential barriers to obtaining PCSK9i therapy.