Therapeutic strategies and reduced drug spending as a signal of early impact of the Enhancing Oncology Model.

1578 Background: Building on lessons learned from the predecessor Oncology Care Model, the Centers for Medicare & Medicaid Services designed the Enhancing Oncology Model (EOM), a voluntary, two-sided risk, episode-based payment model, to incentivize participating practices to provide high-quality, patient-centered oncology care while targeting Medicare spending reductions. At the start of the model, 44 oncology practices voluntarily joined EOM. Practices are held financially accountable for 6-month episodes of care for Medicare Fee-for-Service beneficiaries with 7 high-risk cancers. The objective of this study is to evaluate how practices implemented EOM and whether they were able to reduce Medicare spending during its first six months of implementation. Methods: To identify strategies practices used to meet model goals, we interviewed 93 key informants during site visits at 6 EOM practices from November 2024 through February 2025. We analyzed claims-based impacts on spending using a difference-in-differences approach using a sample of episodes of care from EOM practices and propensity score matched comparison practices during a baseline period (July 1, 2018 – June 30, 2022) and the first performance period of the model (July 1–December 31, 2023). Results: EOM practices reported focusing on reducing drug expenditure. Strategies included (1) substitution to value-based treatment alternatives, such as biosimilars, while mitigating the impact of drug shortages; (2) dose rounding and weight-based dosing to minimize waste and improve efficiency; and (3) avoiding drugs with limited clinical benefit, such as white blood cell growth factors for metastatic tumors. While not statistically significant, we found the model reduced total Medicare spending by $646 per episode (1.1%; 90% confidence interval [CI]: –$1,724, $433), likely driven by reductions in Part B systemic cancer therapy payments of $645 per episode (90% CI: –$1,622, $332). This is consistent with practice reports of implementing value-based prescribing strategies. Conclusions: Early EOM implementation results show emerging evidence of systemic cancer therapy payment reductions. These findings may reflect expanded biosimilar availability and practices' strategic focus on value-based drug substitution and dosing.