Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitor Therapy: Payer Approvals and Rejections, and Patient Characteristics for Successful Prescribing.

Background: Proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) are a novel class of medications for patients with familial hypercholesterolemia or clinical atherosclerotic cardiovascular disease requiring additional lipid lowering beyond dietary measures and statin use. Because of the drugs' high cost, rates of prescription approval by payers may be low. We aimed to identify payer approval and rejection rates for PCSK9i prescriptions and the potential factors influencing these rates.

Methods: This is a retrospective, descriptive cohort study using nationwide pharmacy claims linked to electronic medical records from a nationwide data warehouse. The data set includes >220 million patients from all 50 states and all payer types with 5140 distinct health plans. PCSK9i prescriptions were submitted for 51 466 patients in the pharmacy data set. The main outcome was approval or rejection of PCSK9i prescription claims. Factors associated with approval and rejection of these medications in the United States were assessed.

Results: Among patients who were prescribed a PCSK9i, 47.0% were approved for coverage by the payer. Variables that were associated with PCSK9i approval included age >65 years (<0.01), history of atherosclerotic cardiovascular disease (<0.01), prescription by a cardiologist or nonprimary care provider (<0.01), statin intolerance (=0.03), longer statin duration (=0.01), and noncommercial payers (<0.01). Higher low-density lipoprotein cholesterol levels were not associated with higher approval rates. Commercial third-party payers had the lowest approval rates (24.4%) and Medicare had the highest (60.9%).

Conclusions: Rates of approval for PCSK9i therapy are low, even for patients who appear to meet labeled indications. Although a combination of clinical characteristics increases the likelihood of approval, payer type is the most significant factor.