Baseline endogenous corticosteroid as a biomarker for predicting response to immune checkpoint blockade in patients with metastatic cancer.

Abstract

e14588 Background: Previous studies indicate that exogenous use of corticosteroids affects immune checkpoint inhibitor (ICI) efficacy comparing patients receiving corticosteroids versus no corticosteroids. However, there is a paucity of clinical data evaluating the direct effect of endogenous corticosteroids on ICI efficacy for cancer patients with immune checkpoint blockade. Methods: We retrospectively reviewed patients with advanced cancer who were treated with PD-1 inhibitor alone or combination therapy in a single center between December 2019 and January 2022. Serum corticosteroid levels (8:00 AM) were routinely measured before ICI treatment. The effects of serum corticosteroids on objective response rate (ORR), progression‐free survival (PFS), and overall survival (OS) were analyzed. Propensity score matching (PSM) analysis was performed to match the characteristics of the high and low serum corticosteroid groups. Results: A total of 144 patients were included in this retrospective cohort study. The median age was 62.5 years and 71.5% was male. Overall, ORR was 20.1%, and median OS and PFS were 22.2 and 4.9 months, respectively. Patients with low corticosteroid levels (n = 64) had a significantly improved ORR compared to those with high corticosteroid levels (n = 80) (34.4% vs 8.8%; p < 0.001). The increased corticosteroid level was significantly associated with reduced OS ( p < 0.001) and PFS ( p = 0.025) for all patients and those with non-small cell lung cancer regarding OS ( p = 0.004). Moreover, statistically significant differences regarding OS ( p = 0.017) were also detected after PSM. In a multivariable model, the corticosteroid level was identified as an independent indicator for predicting OS ( p = 0.001) and PFS ( p = 0.006). Conclusions: Endogenous corticosteroid can predict efficacy and prognosis for advanced cancer patients with immune checkpoint blockade. Baseline evaluation of baseline corticosteroids should be considered before ICI initiation. Further prospective clinical trials designed to validate the predictive role of endogenous corticosteroid are warranted.