The Impact of Biosimilar Use on Total Cost of Care and Provider Financial Performance in the Medicare Oncology Care Model: A Population-Based Simulation Study.

Introduction: Payment for oncology care is increasingly moving from fee-for-service to value-based payment (VBP). VBPs are agreements in which providers are held accountable for total cost of care (TCOC) through risk-sharing arrangements with payers that tie reimbursement levels to TCOC benchmarks. Oncology biosimilars may play an important role in managing financial risk in the VBPs like Medicare's Oncology Care Model (OCM), but there has been limited research in this area. The objective of this study is to estimate the impact of biosimilar adoption on TCOC and oncology provider financial performance under the terms of the Medicare OCM.

Methods: We conducted a population-based simulation study using the Medicare Limited Data Set (LDS) and the methodology of Medicare's OCM. The primary outcome was the simulated average change in TCOC per 6-month episode of care attributable to use of biosimilars as an alternative to reference products. The study population consisted of episodes of care in 2020 and using the reference product or corresponding biosimilar for bevacizumab, rituximab, trastuzumab, epoetin alfa, filgrastim, or pegfilgrastim. TCOC was calculated for each episode of care with use of reference products only and compared with TCOC with corresponding biosimilars. The simulation calculated TCOC outcomes in cohorts of 100 episodes sampled from the Medicare LDS study population using a Monte Carlo simulation with 10,000 iterations.

Results: Among the total of 8281 6-month oncology care episodes identified in the study period (initiating January 2020 to July 2020) in Medicare claims, 1586 (19.2%) episodes met OCM and study criteria and were included. Applying the simulation methods to these observed episodes, biosimilar substitution reduced mean TCOC per episode by $1193 (95% CI $583-1840). The cost reduction from biosimilars represented 2.4% of the average TCOC benchmark and led to a 15% reduction in the risk of providers needing to pay recoupments to Medicare for exceeding TCOC benchmarks.

Conclusions: On the basis of our simulation study using observed Medicare claims and OCM criteria, we found that biosimilar substitution for reference products can significantly lower episode TCOC and improve provider financial performance under the terms of the largest value-based payment model implemented to date.