Financial impact of fixed-dose versus weight-based dosing approaches for pembrolizumab and nivolumab in the Oncology Care Model for The US Oncology Network (The Network).

person Jennifer Fernandez McKesson, The US Oncology Network, The Woodlands, TX info_outline Jennifer Fernandez, Puneeth Indurlal, Jody S. Garey, Lalan S. Wilfong

Authors person Jennifer Fernandez McKesson, The US Oncology Network, The Woodlands, TX info_outline Jennifer Fernandez, Puneeth Indurlal, Jody S. Garey, Lalan S. Wilfong Organizations McKesson, The US Oncology Network, The Woodlands, TX, The US Oncology Network, The Woodlands, TX Abstract Disclosures Research Funding No funding sources reported Background: PD-1/PD-L1 antagonists, pembrolizumab and nivolumab, are being used in an increasing number of cancer types. The FDA initially approved both agents based on a weight-based dosing (WBD) approach, but subsequently included a therapeutically equivalent fixed-dose (FD) approach for most indications. The Oncology Care Model (OCM) was a value-based care (VBC) program from Medicare that required total cost of care (TCOC) accountability from participating practices. We evaluated the impact of using the FD vs WBD on TCOC in the OCM for both pembrolizumab and nivolumab. Methods: Using Medicare claims data for 14 OCM-participating practices in The Network from July 2016 to June 2022, and corresponding weight data from the Electronic Health Record (EHR), we evaluated the distribution of patient weights, use of FD vs WBD, and the financial impact of the use of FD vs WBD vs weight-based dosing capped at the fixed dose (WBDc). Results: Summary statistics are shown (Table). In most cases, the FD was higher than the WBD for both nivolumab and pembrolizumab. FD led to an increase in drug cost of 8.4% for nivolumab and 27.2% for pembrolizumab, corresponding to a 11.3% increase in TCOC for the episodes where FD nivolumab and pembrolizumab were used. Conclusions: Fixed-dosing approaches for commonly used high-cost anti-neoplastic drugs can drive increases in TCOC. The use of WBD could lead to a decrease in drug cost and 11.3% savings of TCOC within OCM-like models, likely without impacting clinical outcomes. These findings encourage practices in risk-bearing models to reflect on the widespread adoption of FD. The withdrawal of varying sizes of vials can limit the use of WBD. Pharmaceutical manufacturers should assist with WBD by providing multi-use vials and varying sizes. The feasibility of using the WBD for pembrolizumab with an every 6-week regimen remains to be explored. Drug Name Total Number of Administrations (Admins) Fixed Dose Admins Fixed Dose Admins With Weight Data Mean (SD) Weight Percentiles (5 th , 25 th , 50 th , 75 th , 95 th ) Nivolumab 81,021 59,452 (73.4%) 55,712 (93.7%) 76.76 (19.28) 46.98, 63.00, 76.14, 88.38, 110.25 Pembrolizumab 80,770 78,800 (97.6%) 74,379 (94.4%) 72.96 (19.16) 45.45, 59.04, 71.10, 84.60, 106.65 Drug Name WBD < FD WBD = FD WBD > FD Nivolumab 52.01% (28976) 12.53% (6979) 35.46% (19757) Pembrolizumab 79.98% (59490) 16.50% (12271) 3.52% (2618) Measure Drug FD WBD WBDc Cost per admins Nivolumab $6,171 $6,000 $5,494 Pembrolizumab $8,138 $5,949 $5,868