3706 - Time and Financial Toxicity Implications during Consideration of Pembrolizumab Infusion Frequency

S. Nori¹, G. Strohbehn², and A. K. Bryant³; ¹University of Michigan Medical School, Ann Arbor, MI, ²Department of Medicine, Division of Hematology and Oncology, University of Michigan, Ann Arbor, MI, ³Department of Radiation Oncology, Veterans Affairs Ann Arbor Health System, Ann Arbor, MI

Purpose/Objective(s): Per Food and Drug Administration (FDA) regulation, pembrolizumab can be administered as a 200mg dose every 3 weeks (Q3W) or as a 400mg dose every 6 weeks (Q6W) for various cancers. Little to no literature exists on time toxicity and transportation-related out-of-pocket expenditure for patients when considering the frequency of pembrolizumab infusions. We aimed to model differences in time toxicity and transportation costs between the status quo and institutionalized transitions to Q6W infusions for patients receiving care at United States (US) Veteran’s Affairs (VA) hospitals using a simulation-based approach. Materials/

Methods: Data was extracted from VA medical records of patients who received pembrolizumab infusions with or without chemotherapy or a tyrosine kinase inhibitor (TKI). Extracted data included driving distance from patient residence to the hospital, driving duration, type of infusion (pembrolizumab ± chemotherapy ± TKI), location of infusion site, and infusion dates. Distance and time data was extrapolated into scenarios defined by 1) pembrolizumab ± chemotherapy ± TKI transitioning to Q6W, i.e. “universal Q6W infusions” and 2) pembrolizumab-only infusions transitioning to Q6W, i.e. “monotherapy Q6W infusions." Gasoline expenditure was calculated as a multiplied product of patient driving distance, location-specific, monthly average gasoline price data from 2003 to 2023 and average light-duty US car fuel efficiency data published by US government agencies. Time toxicity was calculated as the sum of cumulative and per-infusion driving durations with published estimates of pembrolizumab infusion duration and associated duration of patient visits in the Q3W and Q6W setting.
Results: 7891 patients spanning 102 VA hospitals underwent treatment with pembrolizumab, comprising a total of 58639 infusions. Each hospital treated, on average, 77 (± 55) patients and delivered an average of 575 (± 421) infusions. Compared to the status quo, the mean total driving time for a complete treatment course was 71.4 minutes less per patient with a transition to universal Q6W infusions and 70.1 minutes less per patient with a transition to monotherapy Q6W infusions. Compared to the status quo, transitioning to universal and monotherapy Q6W infusions saved an average of 9.09 USD and 8.96 USD per patient respectively in gasoline costs for an entire treatment course. Additionally, transitioning to universal and monotherapy Q6W infusions saved an average of 361 minutes and 332 minutes per patient respectively for a complete treatment course.
Conclusion: Our models show that transitioning from Q3W to Q6W infusions of pembrolizumab ± chemotherapy ± TKI lowers both transportation-related costs and time toxicity in VA patients. As such, Q6W infusions may represent a more cost-effective means of treatment delivery if deemed clinically appropriate.