Bone-modifying agents and survival in patients treated with immune checkpoint inhibitors

Aims: Management of bone metastasis is crucial for cancer patients. The objective of this study was to assess the correlation between survival outcomes and bone-modifying agents (BMAs) in patients treated with immune checkpoint inhibitors (ICIs). Methods: This study was conducted in individuals who received at least 3 doses of ICIs between January 2018 and December 2023 and had bone metastases at initiation of ICIs. We retrospectively collected data on each patient from their medical records, including information on cancer, the specific immunotherapy treatment, and the BMAs they were receiving. Results: 142 patients were included. The median follow-up was 36 [interquartile range (IQR)=18-50] months and the median follow-up from the initiation of BMAs to the last control was 14 months (IQR=5-29). After adjustment for age, gender, Eastern Cooperative Oncology Group (ECOG) score and number of prior treatment lines in the multivariate analyses, patients who did not use BMAs had decreased overall survival (OS) (HR: 2.30, 95%CI: 1.03-2.45; p=0.036). In addition, BMAs use was associated with long-term benefit defined as having a survival of equal to or longer than 24 months (HR: 2.85, 95%CI 1.13-7.21; p=0.027). Conclusion: It was found that using BMAs could be an independent predictor of OS in patients treated with ICI and who had bone metastasis. This finding may lead clinicians to start BMAs as soon as possible after bone metastases are detected.