Molecular characterization of nectin-4 in non-small cell lung cancer subtypes.

Abstract

e21119 Background: Nectin-4 (Nectin cell adhesion molecule-4) is a tumor associated antigen overexpressed in multiple solid tumor types. Studies show that over 60% of NSCLC are nectin-4 overexpressed. As enfortumab vedotin, an antibody-drug conjugate directed against nectin-4, has been FDA approved for advanced urothelial carcinoma, this holds treatment implications. Here, we investigated nectin-4 expression in NSCLC subtypes. Methods: 27,607 NSCLC tumors were tested for whole transcriptome sequencing (WTS, NovaSeq) and NextGen DNA sequencing (592 gene panel or whole exome sequencing, WES) at Caris Life Sciences (Phoenix, AZ). Tumors were analyzed overall in quartiles by nectin-4 expression (Q4-greatest, Q1-least) and further analyzed in the adenocarcinoma (AD) and squamous carcinoma (SQ) cohorts. PD-L1 expression was tested by IHC (Dako 22C3). Immune cell populations were estimated by QuanTISeq. Statistical significance was determined using Chi-square/Fisher-Exact/Mann-Whitney U tests and adjusted for multiple comparisons (q < 0.05). Results: We saw significantly greater expression of nectin-4 in SQ (median TPM- 15.68) versus AD tumors (median TPM - 9.88) (p < 0.05). We saw a greater prevalence of NFE2L2, STK11, ERBB2 mutations and genomic loss of heterozygosity (LOH) but a lower percentage of PD-L1+ tumors in Q4 vs Q1 tumors (all q-value < 0.05, Table 1). mRNA expression of immune checkpoints PDL1, CTLA4, CD80, CD86, HAVCR2, and IDO1 was increased in Q4 tumors (1.1-1.3-fold, all q < 0.05). Q4 tumors had reduced estimates of M1 macrophages, regulatory T cells (Tregs), and CD8+ T cells and increased estimates of neutrophils and NK cells. The association of nectin-4 expression with the immune landscapes of AD and SQ was similar. Q4 tumors in AD and SQ displayed increased expression of the above-mentioned immune checkpoints (q < 0.05). In AD and SQ, estimates of M1 macrophages, Tregs, and CD8+ T cells were reduced, but neutrophils and NK cells were increased in Q4 tumors (q < 0.05). The pattern of molecular alterations was different in AD and SQ. While KEAP1, STK11 and ERBB2 mutations were significantly enriched in AD Q4 tumors, NFE2L2 mutations were significantly enriched in SQ Q4 tumors (Table 1). Prevalence of LOH was higher and PD-L1+ tumors was lower in Q4 tumors in both AD and SQ (Table 1). Conclusions: NFE2L2 alterations in SQ and STK11, KEAP1 mutations in AD, which are associated with poor immunotherapy (IO) response, were enriched in Q4 tumors. This suggests that the immune landscape associated with high nectin-4 expression in NSCLC may be driven by the dysregulated KEAP1-NFE2L2 pathway. Targeted therapy towards nectin-4 may benefit these NSCLC subtypes that do not respond well to IO. [Table: see text]