Modeling the survival impact of the Inflation Reduction Act out-of-pocket cap in multiple myeloma
Han Zhao, Stanley Teng, Cynthia Dong, Ziyun Meng, Qingyuan Tan, Rong Wang, Mengmeng Ji, Martin W Schoen, Kristen M Sanfilippo, Mark A Fiala, Shi-Yi Wang, Su-Hsin ChangAbstract
Background
Oral immunomodulatory imide drugs (IMiDs) have become standard of care for newly diagnosed multiple myeloma (NDMM), but high out-of-pocket (OOP) costs may hinder treatment adherence. In 2025, the Inflation Reduction Act introduced a $2,000 annual OOP cost cap (IRAOOPcap) for Medicare Part D beneficiaries. In the absence of post-implementation data, we used comparative modeling to predict its survival impact.
Methods
The survival submodels of two independent Cancer Intervention and Surveillance Modeling Network (CISNET) natural history of multiple myeloma models were used. The models were parameterized using data from Surveillance, Epidemiology, and End Results (SEER)-Medicare, 2012–2021. We simulated survival among Medicare Part D beneficiaries with NDMM aged 66–75 and ≥76 years, under hypothetical scenarios shifting 0% (pre-IRAOOPcap) to 100% (best-case) of patients to IMiD use with high adherence and a realistic scenario using published data. We computed life-years gained (LYG) by comparing life expectancy (LE) under each scenario with that of the pre-IRAOOPcap scenario.
Results
Across models, the realistic/best-case scenario yielded LYG of 0.17–0.18/1.10–1.35 among patients aged 66–75 years, and 0.20–0.26/1.29–1.53 for those aged ≥76 years. These translated into 4,164–5,005/26,893–32,347 LYG at the population level for beneficiaries with NDMM in 2025.
Conclusion
The IRAOOPcap may improve survival through increasing IMiD utilization and adherence among Medicare Part D beneficiaries with NDMM. The projected gains represent a meaningful proportion of contemporary survival for patients. Future research should validate these gains when real-world data are available and inform future policy adaptation and extension.