Correlation of Peripheral Blood Parameters and Immune-Related Adverse Events with the Efficacy of Immune Checkpoint Inhibitors

OBJECTIVE: We aimed to retrospectively analyze the predictors of immune checkpoint inhibitors (ICIs)-efficacy in patients with advanced pancancer who were treated with various ICIs in the real world and focused on the correlation between ICIs-efficacy and immune-related adverse events (irAEs). METHODS: We retrospectively analyzed data from 103 patients with advanced pancancer treated receiving various ICIs in the First Hospital of Jilin University from January 1, 2016 to August 1, 2020. Survival probabilities of progression-free survival (PFS) and overall survival (OS) were estimated using Kaplan–Meier curves and log-rank tests and the multivariate Cox proportional hazards model. Receiver-operating characteristic curve was used to determine a cutoff value for parameters and area under the curve. Correlations between the two variables were analyzed by logistic regression. RESULTS: All patients were analyzed for survival predictors of OS, while 87 of 103 patients experienced evaluable disease progression of immunotherapy and were included in the analysis of predictors of PFS. First, we found that lower platelet (cutoff = 201.5 × 10(9)/L) and lactate dehydrogenase (LDH) (cutoff = 227 U/L) were independently associated with significantly improved PFS, while lower platelet-lymphocyte ratio (cutoff = 206.5), absolute monocyte count (cutoff = 0.62 × 10(9)/L), and LDH (cutoff = 194.5 U/L) were significantly and independently associated with better OS. In the analysis of the immune cell subgroup, a lower absolute countof CD8(+)CD28(−)suppressor T cells was an independent factor associated with better PFS (6.60 vs.4.13 months (mo), hazard ratios (HR) = 3.17, p = 0.0038), and OS (29.4 vs. 9.57 mo, HR = 3.05, p = 0.03). Second, the results of the analysis for irAEs showed that patients with any grade irAEs had higher objective response rate (30% vs. 10%, HR = 4.34, p = 0.009), disease control rate (69.7% vs. 50%, HR = 2.3, p = 0.028), PFS (8.37 vs. 3.77 mo, HR = 2.02, p = 0.0038), and OS (24.77 vs.13.83 mo, HR = 1.84, p = 0.024). Moreover, the groups with irAEs of grade ≥2 and with “multi-site” irAEs had significantly better PFS and OS (p < 0.05) compared with the other groups. We also proved that endocrine irAEs (usually thyroid dysfunction) were significantly associated with better mPFS (p = 0.01), and hepatic irAEs were significantly associated with better mOS (p = 0.023). CONCLUSIONS: This retrospective study explored the availability and effectiveness of some cost-effective and readily available blood biochemical parameters in routine clinical practice to predict the ICIs-efficacy and demonstrated the predictive role of different categories of irAEs on efficacy.