Medicare Advantage premium, utilization management, and costs for generic abiraterone and imatinib.

84 Background: Medicare Advantage (MA) now covers over half of all beneficiaries, with zero-premium plans accounting for 70% of MA enrollment. While financially attractive, this trend raises policy concerns about potential trade-offs between low premiums and access to oncology drugs. This study examines the correlation between MA premiums, utilization management (UM), and total drug costs for two high-spending, early-entry generic oncology drugs that serve as key tests of MA plan generosity. Methods: We conducted a cross-sectional analysis using CMS Public Formulary data (Q4 2024). We included Health Maintenance Organization (HMO), HMO Point-of-Service (HMO-POS), and Preferred Provider Organization (PPO) Medicare Advantage plan with PartD drug benefits; and excluded employer-sponsored and Special Need Plans (including those for dual-eligible individuals). We assessed formulary coverage, UM requirements (Prior Authorization [PA], Quantity Limits [QL], Step Therapy [ST]), and plan-level monthly total costs for generic abiraterone 250mg and imatinib 100mg. Plans were stratified by monthly premium ($0, $0.01-$50, >$50). We compared UM prevalence and total cost by premium level using chi-square test and generalized linear models respectively. Results: All 2,713 analyzed plans covered generic abiraterone and imatinib, with no ST requirements on either drug. Zero-premium plans, enrolling the most beneficiaries (13.98M), consistently imposed higher UM and greater costs for both drugs. (Table) For abiraterone, these $0 plans had the highest monthly total cost ($1804.69), PA (92.0%) and QL rate (76.9%), while >$50 premium plans featured the lowest cost ($1433.29), PA (69.9%) and QL rate (69.9%). Similarly for imatinib, $0 plans demonstrated the highest monthly total costs ($1874.25), PA (91.6%), and QL rates (89.5%); in contrast, >$50 plans offered the lowest costs ($1466.86) alongside lower PA (83.9%) and QL (81.0%) rates. An inverse association between premium level and costs was observed for both drugs (both p<0.01). Conclusions: While utilization management for generic abiraterone and imatinib is notably high across MA plans, popular zero-premium plans exhibit even more restrictive UM and higher total costs. This creates potential hidden access barriers, warranting urgent investigation into their impact on cancer care as these plans grow, to ensure equitable access to necessary treatments. Utilization management and monthly total cost of generic abiraterone and imatinib by MA plan monthly premium tier. Abiraterone Imatinib Premium N (Plans) Enrolled No. PA (%) QL (%) Cost PA (%) QL (%) Cost $0 1912 13,981,085 92.0% 76.9% 1804.69 91.6% 89.5% 1874.25 $0.01-50 650 3,548,245 88.1% 75.9% 1538.55 86.1% 86.2% 1545.03 $50+ 151 514,808 88.1% 69.9% 1433.29 83.9% 81.0% 1466.86 All MA plans provide coverage for both drugs, and none apply Step Therapy as a utilization management (UM) requirement.