Oncology drug abandonment after capping of annual out-of-pocket costs under Medicare Part D in 2024.

97 Background: Medicare enrollees with cancer face high out-of-pocket (OOP) costs for specialty oral anticancer medications (SOAM), resulting in frequent prescription abandonment. Starting 1/1/24, the Inflation Reduction Act (IRA) eliminated the 5% coinsurance in the Medicare Part D catastrophic coverage phase for enrollees without Low-Income Subsidies (LIS). We estimated the impact of this change on SOAM prescription abandonment among non-LIS enrollees. Methods: We used the Symphony Health Solutions’ Integrated Dataverse claims database (1/1/23-6/30/24, the latest available data at time of analysis), evaluating Medicare enrollees with a new insurer approved SOAM claim (i.e., index prescription) for solid tumors between 1/1/23-4/30/23 and 1/1/24-4/30/24, allowing for a 60-day follow-up to measure abandonment. Outcomes for the index prescription were OOP cost, reversal (i.e., not filling the prescription), and abandonment (i.e., reversal with no evidence of filling the same drug over a 60-day follow-up). Multivariable difference-in-differences models estimated changes in outcomes before (2023) and after (2024) the IRA’s 2024 change for non-LIS enrollees relative to a control group of full LIS enrollees, whose cost-sharing remained low and relatively unchanged across this period. Results: Our study included 7,408 non-LIS and 1,897 full LIS enrollees with an insurer approved index prescription. From 2023 to 2024, mean OOP costs for the index prescription decreased from $2,910 to $2,400 (p < 0.001) for non-LIS and were unchanged from $2.66 to $1.62 (p = 0.86) for full LIS enrollees. Adjusted prescription reversals decreased from 74.6% to 63.2% (p < 0.001) for non-LIS and was unchanged from 23.4% to 22.5% (p = 0.69) for LIS enrollees (DID = -10.5 [95% CI -15.1 to -5.9]. Adjusted prescription abandonment decreased from 71.5% to 57.7% (p < 0.001) for non-LIS and was unchanged from 18.4% to 17.8% (p = 0.78) for LIS enrollees (DID = -13.2 [95% CI -17.7, -9.0]. Prior to IRA changes, from 2022 to 2023, there was no differential change in reversals or abandonment. Conclusions: The OOP cost for a new insurer-approved SOAM prescription dropped by ~500 for non-LIS enrollees after IRA’s annual OOP cap in 2024, decreasing prescription abandonment by 13 percentage points. However, over half of non-LIS enrollees still abandoned their SOAM in 2024, possibly because despite capping annual OOP costs, often the costs were front-loaded for a single new prescription. Starting 2025, the IRA lowered the annual OOP cap to 2,000. It also created a new voluntary program—the Medicare Prescription Payment Plan (MPPP)—that allows patients to spread OOP costs across monthly payments. Yet most enrollees are unaware of the MPPP. Our study suggests that an annual cap alone may not improve SOAM access for the majority. It is crucial that cancer societies and practices inform enrollees using SOAMs about the benefits of MPPP enrollment.