Abstract 1148: Multimodal spatial transcriptomics and proteomics analysis of the resectable NSCLC ecosystem following neoadjuvant chemoimmunotherapy

Abstract Neoadjuvant and perioperative immunotherapy with checkpoint inhibitors (ICIs), combined with chemotherapy (CT), have improved outcomes for patients with resectable non-small cell lung cancer (NSCLC). Pathologic tumor response has been utilized in clinical trials as a surrogate of clinical efficacy. Yet, over half of treated patients experience non-response, highlighting the need for novel markers to identify those who are most likely to derive therapeutic benefit. To dissect the spatial complexity of the tumor-associated immune landscape following neoadjuvant chemoimmunotherapy (CT+ICI), we selected patients (n =3) with a range of residual viable tumor (%RVT) - pathological complete response (pCR; 0% RVT), partial response (20% RVT), and no-response (100% RVT). We performed multimodal spatial transcriptomics (ST) and proteomics (using a 35-plex protein panel) on the same tissue sections using the Visium CytAssist from 10X Genomics. We also examined spatial patterns of 20-plex panel of immune and stromal markers at single-cell resolution in the same samples using the COMET Lunaphore platform. In the pCR patient, we studied two tumor areas to assess the impact of tumor response heterogeneity on the immune landscape. Our analysis identified distinct immune profiles across three patients with varying %RVT, reflecting the heterogeneity of the immune response. We found robust gene-protein correlation, such as MS4A1 gene expression and CD20 protein levels, in our multimodal spatial-omics analysis. Intriguingly, the arrangement of B cells and their interaction with surrounding plasma cells (PCs) varied notably across patients. Unlike in the patients with partial or no response, pronounced tertiary lymphoid structure (TLS) formation and signatures were observed in the pCR patient, with the CXCL13-CXCR5 axis overlapping with the TLS profile, suggesting a functional interplay that may be crucial in mediating response to therapy. Intriguingly, in the pCR patient, PCs uniquely arrayed around dense B cell aggregates, marked by MS4A1, CR2, FCER1, and CXCL13. PCs were not only less abundant in non-PCR patients but they also did not array around lymphoid aggregates. Our high-resolution and multimodal analysis identified spatially-resolved expression and patterns for B lineage cells that may be associated, and thus, underlie response of resectable NSCLC to neoadjuvant CT+ICI. Ongoing efforts on this expanding cohort will shed further light on transcriptional states and immunogenomic roles of B lineage cells in neoadjuvant CT+ICI-treated NSCLC. Citation Format: Zahraa Rahal, Tieling Zhou, Sujuan Yang, Alejandra Serrano, Jiping Feng, Ansam Sinjab, John T. Le, Xin Sun, Michael Wang, Wei Hu, Jianjun Zang, Tullia Bruno, Hai T. Tran, Stephen G. Swisher, Cheuk Hong Leung, Heather Y. Lin, J. Jack Lee, Jing Wang, John Victor Heymach, Don Lynn Gibbons, Ignacio Ivan Wistuba, Annikka Weissferdt, Jared K. Burks, Luisa Maren Solis Soto, Humam Kadara, Tina Cascone. Multimodal spatial transcriptomics and proteomics analysis of the resectable NSCLC ecosystem following neoadjuvant chemoimmunotherapy abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 1148.