131P - Systemic immune-inflammation index and overall survival with checkpoint inhibitors

Background

Immune checkpoint inhibitors (ICIs) are widely used for cancer treatment, yet predictive biomarkers are lacking. The Systemic Immune-Inflammation Index (SIII) is calculated from routine blood tests (neutrophils/lymphocytes * platelets) and is a marker of immune status. We investigated associations of pre-treatment SIII with overall survival (OS) in commonly used ICI regimens in a pan-cancer cohort.

Methods

We included patients with advanced cancer who received ICIs at The Christie NHS Foundation Trust, UK, from 2018 to 2023. SIII was calculated from pre-treatment blood tests, with patients classified as either above or below the median. Median OS (mOS) and survival rates at 1 year according to pre-treatment SIII were estimated by the Kaplan-Meier method. Hazard ratios (HRs) and 95% CIs for OS were estimated using Cox regression, adjusted for age, sex, performance status, ICI and diagnosis.

Results

We included 2579 patients with non-small cell lung cancer (NSCLC, n=972), melanoma (n=598), renal cancer (n=469), head and neck (H&N) cancer (n=251), small cell lung cancer (SCLC, n=164) and bladder cancer (n=125). mOS was 17.1 months and 1-year survival was 59.3%. Below-median pre-treatment SIII was strongly associated with OS for all patients combined (mOS 28.1 vs. 11.1 months, p < 0.0001; 1-year survival 70.1% vs. 48.3%; HR 0.56, 95% CI 0.50-0.62) and for almost all individual regimens. This included pembrolizumab (pem) or atezolizumab (atez) with chemotherapy (ChT) in NSCLC (OS HR 0.67, 95% CI 0.52-0.87), nivolumab (nivo) and ipilimumab (ipi) in melanoma (OS HR 0.53, 95% CI 0.37-0.77) and renal cancer (OS HR 0.24, 95% CI 0.14-0.40), and pem or atez in bladder cancer (OS HR 0.60, 95% CI 0.38-0.95, see table). Table: 131P

mOS and HR of OS according to pre-treatment SIII

* Not reached, † tyrosine kinase inhibitor.

Conclusions

Pre-treatment SIII is strongly associated with OS in patients with advanced cancers receiving ICIs and, as such, has potential as a predictive biomarker.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The Christie NHS Foundation Trust.

Funding

Has not received any funding.

Disclosure

R. Lee: Financial Interests, Personal, Funding: BMS, Pierre Fabre, AstraZeneca; Financial Interests, Personal, Speaker, Consultant, Advisor: Pierre Fabre. P. Lorigan: Financial Interests, Personal, Advisory Board, ASCO2023 participation, travel support: MSD; Financial Interests, Personal, Advisory Board: NeraCare; Financial Interests, Institutional, Research Grant: BMS, Pierre Fabre; Non-Financial Interests, Other, invited speaker: Melanoma Focus charity; Non-Financial Interests, Other, invited session chair: SMR Edinburgh 2022; Non-Financial Interests, Leadership Role, current 2023 Chairman of group: EORTC Melanoma Group; Non-Financial Interests, Other, clinical research committee: CRUK. All other authors have declared no conflicts of interest.