Lack of Association Between Glucose Homeostasis and Immune Checkpoint Inhibitor Outcomes: A Retrospective Institutional Review

Background/Objectives: Immune checkpoint inhibitors (ICIs) have revolutionized outcomes for patients with melanoma. As such, it is important to understand factors that may influence response as well as toxicity to these therapies. Impaired glucose control is often a sign of pathologic inflammation and may alter immune system regulation, but it is unclear whether glucose control impacts patients with melanoma on ICIs. Methods: After reviewing patients with melanoma treated with ICIs at our institution between 2014 and 2024, we assessed whether longitudinal glucose control is associated with patient outcomes (response, progression-free survival, overall survival, and treatment toxicity) during ICI therapy. Results: There was no significant difference in baseline glucose values between responders and non-responders (102.5 vs. 106.0, p = 0.093). Having a baseline glucose over 200 or any glucose over 200 was not significantly associated with response (p = 0.79, p = 0.20), progression-free survival (p = 0.64, p = 0.45), overall survival (p = 0.56, p = 0.36), or toxicity (p = 0.29, p = 0.11). Although a diagnosis of diabetes mellitus was not significantly associated with response (p = 0.84), progression-free survival (p = 0.12), or toxicity (p = 0.11), it was associated with improved overall survival (p = 0.0034) in the small number of patients with diabetes. Conclusions: Overall, we observed that glucose control was not strongly associated with efficacy or toxicity in patients treated with ICIs.