Immunotherapy Initiation at the End of Life in Patients With Metastatic Cancer in the US

Importance While immunotherapy is being used in an expanding range of clinical scenarios, the incidence of immunotherapy initiation at the end of life (EOL) is unknown.Objective To describe patient characteristics, practice patterns, and risk factors concerning EOL-initiated (EOL-I) immunotherapy over time.Design, Setting, and Participants Retrospective cohort study using a US national clinical database of patients with metastatic melanoma, non-small cell lung cancer (NSCLC), or kidney cell carcinoma (KCC) diagnosed after US Food and Drug Administration approval of immune checkpoint inhibitors for the treatment of each disease through December 2019. Mean follow-up was 13.7 months. Data analysis was performed from December 2022 to May 2023.Exposures Age, sex, race and ethnicity, insurance, location, facility type, hospital volume, Charlson-Deyo Comorbidity Index, and location of metastases.Main Outcomes and Measures Main outcomes were EOL-I immunotherapy, defined as immunotherapy initiated within 1 month of death, and characteristics of the cohort receiving EOL-I immunotherapy and factors associated with its use.Results Overall, data for 242 371 patients were analyzed. The study included 20 415 patients with stage IV melanoma, 197 331 patients with stage IV NSCLC, and 24 625 patients with stage IV KCC. Mean (SD) age was 67.9 (11.4) years, 42.5% were older than 70 years, 56.0% were male, and 29.3% received immunotherapy. The percentage of patients who received EOL-I immunotherapy increased over time for all cancers. More than 1 in 14 immunotherapy treatments in 2019 were initiated within 1 month of death. Risk-adjusted patients with 3 or more organs involved in metastatic disease were 3.8-fold more likely (95% CI, 3.1-4.7; P < .001) to die within 1 month of immunotherapy initiation than those with lymph node involvement only. Treatment at an academic or high-volume center rather than a nonacademic or very low-volume center was associated with a 31% (odds ratio, 0.69; 95% CI, 0.65-0.74; P < .001) and 30% (odds ratio, 0.70; 95% CI, 0.65-0.76; P < .001) decrease in odds of death within a month of initiating immunotherapy, respectively.Conclusions and Relevance Findings of this cohort study show that the initiation of immunotherapy at the EOL is increasing over time. Patients with higher metastatic burden and who were treated at nonacademic or low-volume facilities had higher odds of receiving EOL-I immunotherapy. Tracking EOL-I immunotherapy can offer insights into national prescribing patterns and serve as a harbinger for shifts in the clinical approach to patients with advanced cancer.