Real-world data on time toxicity experienced by patients on select immune checkpoint inhibitor regimens in their last year of life.

351 Background: Time toxicity, the burden of time spent in healthcare, can impact patient quality of life, particularly at the end of life (EOL). The relatively high tolerability profiles of some therapies, like immune checkpoint inhibitors (ICI), means that they favor use at the end-of-life. Several have extended dosing paradigms that reduce infusion visits, but real-world data on these regimens and their impact on patients at EOL is limited. This study describes the time toxicity of select single-agent ICI regimens used during the last year of life. Methods: We obtained electronic health data from patients treated at a large national community oncology practice, who had a record of death between January 1, 2022 and May 25, 2025 and underwent NCCN guideline- based regimens for single-agent pembrolizumab (Keytruda) or nivolumab (Opdivo) in the last year of life for at least 30 days. Regimen inclusion required a minimum cohort size of 30 patients. Patients with multiple regimens were assigned the cohort with the latest regimen end date. Oncology practice time toxicity was defined as the number of unique days in the charge history of the practice EHR during the last year of life. The number of days between the regimen end date and date of death was also measured. Results: A total of 424 patients were included (321 pembrolizumab-only, 103 nivolumab-only, 1 experienced both). Quartiles of the oncology-practice time toxicity and the number of days between regimen end date and death are reported by regimen (rounded to day). Conclusions: Patients experience variable time toxicity with single-agent ICI regimens at the EOL; these data can inform shared decision-making with patients. Extended interval dosing may alleviate time commitment and reduce the use of therapy at the end of life, though further study is needed to delineate how much differences between observational cohorts are driven by treatment-related factors. This study does not include care external to the practice, so it underestimates total time toxicity. Drug Regimen Description # Patients Percentiles of Oncology-Practice Time Toxicity (days) Percentiles of Regimen End Before Death (days) 25th 50th 75th 25th 50th 75th Pembrolizumab 200mg IV q21d 280 14 22 32 19 45 105 Pembrolizumab 400mg IV q42d 41 11 16 27 29 55 156 Nivolumab 240mg IV q14d 66 19 28 38 15 44 122 Nivolumab 480mg IV q28d 37 12 17 26 30 87 150