Prognostic ability of the Gustave Roussy Immune Score for patients with advanced pancreatic adenocarcinoma.

Abstract

469 Background: The Gustave Roussy Immune Score (GRIm-S) considers a composite of neutrophil to lymphocyte ratio (> 6 = 1), albumin (< 35 = 1) and LDH (> ULN = 1) and has been established as a prognostic score and may in aid in the selection of patients for phase 1 trials of immune checkpoint inhibitors. Methods: We explored the prognostic impact of the GRIm-S (high > 1) in patients enrolled on the COMPASS trial and correlated the score with genomic and clinical characteristics. Patients in this trial had biopsies for whole genomic and RNA sequencing prior to standard chemotherapy regimens in the advanced setting. Results: 252 patients were included in the analyses with a median follow-up time of 28 months. 16% of patients had a high GRIm-S with significantly shorter median overall survival (OS) of 4.1 months versus 10.0 months in those with a low score (HR 2.18, 95% CI 1.4-3.4, p < 0.0001). In the GRIm-S-high cohort, early progression with non-evaluable disease and disease progression were more common than in the GRIm-S low cohort (56% vs 31%, p = 0.003). In a multivariable analysis, a high GRIm-S was poorly prognostic (HR 1.6 95% CI 1.3-1.9, p < 0.001), whereas the classical RNA subtype (vs. basal-like) (HR 0.41, 95% CI 0.3-0.6, p < 0.001) and a high HRDetect score (HR 0.47 95% CI 0.3-0.7, p < 0.001) associated with superior OS. The GRIm-S did not correlate with RNA subtypes or with specific KRAS mutations. There were no differences in structural variant load or tumour mutational burden between groups. However those with a high GRIm-S did have a higher total target lesion diameter at baseline (p < 0.001). Conclusions: The GRIm-S identifies a subset of patients who have aggressive pancreas cancer and short life expectancy. This information may help clinicians in treatment decision making and selection for clinical trials.