Abstract 964: Genomic and clinical predictors of early disease progression and chemoimmunotherapy benefit in advanced NSCLC

Abstract Background: Immune checkpoint inhibitors (ICIs) as monotherapy (ICI-mono) or with chemotherapy (ICI-chemo) are standard first-line treatment in NSCLC patients lacking targetable driver mutations. Biomarkers to identify patients at risk for early progression on ICI-mono or those who would maximally benefit from upfront ICI-chemo have not been defined. Methods: We queried the GEMINI database to identify metastatic NSCLC patients without targetable EGFR/ALK alterations who were treated with ICI-mono or ICI-chemo. Mutational profiling was performed on tissue or blood using targeted NGS. Outcome measures were defined as clinical progression free survival (PFS) or early progressive disease (PD) rate (defined as rate of 3-month progression), and their association with variables was assessed via Cox Proportional Hazards regression (PFS) or logistic regression (early PD). Predictive deep learning models were used to integrate clinicopathological factors and genomic profile. Results: 735 patients were included in this study, 269 treated with ICI-chemo and 466 with ICI-mono; 446 were treated in the first-line setting. TP53 was the most frequently altered gene (60%), followed by KRAS (37%), AR (21%), and STK11 (19%). In ICI-mono patients, alterations in STK11, ERBB2, ARID1A and CDK6 were associated with a higher likelihood of early PD; only STK11 was associated with early PD (29% vs 17%, P = 0.04) on ICI-chemo. In all patients, low PD-L1 expression and high disease burden (stage IVb and liver metastases) associated with early PD, but there were borderline significant treatment effects in favor of ICI-chemo in never smokers and patients with liver metastases and stage IVb. Shorter PFS was observed in the ICI-chemo group who had CDKN2A alterations vs wild type (median PFS: 5.1 vs 9.0 months; HR: 1.72; P = 0.01). A subgroup analysis of patients with CDKN2A alterations demonstrated preferentially worse outcomes in ICI-chemo compared to ICI-mono, with the best PFS achieved in the ICI-mono treated patients with CDKN2A point mutation. Integration of clinicogenomic features into a multivariate model with feature selection to predict early PD demonstrated a predictive performance of AUC 0.73 (vs PD-L1 alone, AUC 0.60) in the ICI-mono group, driven by liver metastases, stage IVb disease, PD-L1 expression, and STK11 alterations. These features were less predictive in ICI-chemo-treated patients, indicating a protective effect against early PD in these patients from combination chemoimmunotherapy. Conclusions: Low PD-L1, high disease burden, and STK11 alterations are markers of early PD on ICI-mono, and patients with these features may particularly benefit from upfront combination treatment with ICI-chemo to protect against early progression. Citation Format: Lingzhi Hong, Muhammad Aminu, Xuetao Lu, Maliazurina B. Saad, Pingjun Chen, Waree Rinsurongkawong, Amy Spelman, Yasir Y. Elamin, Marcelo V. Negrao, Ferdinandos Skoulidis, Carl M. Gay, Tina Cascone, Mara B. Antonoff, Boris Sepesi, Jeff Lewis, Don L. Gibbons, Ara A. Vaporciyan, Xiuning Le, J.Jack Lee, Sinchita Roy-Chowdhuri, Mark J. Routbort, John V. Heymach, Jia Wu, Jianjun Zhang, Natalie I. Vokes. Genomic and clinical predictors of early disease progression and chemoimmunotherapy benefit in advanced NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 964.