Abstract 1211: Biomarker analysis of pembrolizumab and ramucirumab neoadjuvant therapy for PD-L1-positive stage IB-IIIA lung cancer: EAST ENERGY trial

Abstract Background: Neoadjuvant treatments with novel combination immunotherapies for resectable non-small cell lung cancer (NSCLC) are being developed. Combination therapy with antiangiogenic agents and anti-PD-1/PD-L1 antibody has shown enhanced antitumor effects. EAST ENERGY is a single-arm multicenter phase 2 trial of neoadjuvant pembrolizumab and ramucirumab in patients with PD-L1-positive stage IB-IIIA NSCLC (NCT04040361). In this study, we aimed to identify biomarkers that predicts the efficacy of the neoadjuvant therapy. Furthermore, we aimed to elucidate the effect of the neoadjuvant therapy on the tumor microenvironment (TME). Methods: Patients enrolled in the EAST ENERGY trial (n=24) for whom pre- and post-treatment specimens were available (n=20) were included in this study. RNA-sequencing and multiplex immunohistochemistry (mIHC) were used to examine the association between the immunological phenotype of the TME and major pathological response (MPR), and changes in the TME before and after treatment. Results: MPR was achieved in 50.0% (12/24) of patients. Biomarker analyses with RNA-sequencing revealed that high expression of cancer-associated genes, and upregulation of interferon-gamma and interferon-alpha response in pre-treatment tumor were associated with MPR (q value<0.001). mIHC in pre-treatment samples revealed that abundance of CD8+ T cells in the pre-treatment TME was associated with MPR (p=0.039). On the other hand, infiltration of immunosuppressive cells such as Treg or M2-macrophages were not associated with resistance for the treatment (p=0.836, 0.639, respectively). Next, to clarify the effect of the neoadjuvant therapy on the TME, comparative analyses of pre- and post-treatment samples was performed. In gene set enrichment analysis, the neoadjuvant therapy enhanced gene set associated with interferon-gamma response (q value=0.051). Furthermore, angiogenesis-related gene set were downregulated after the treatment (q value=0.090). mIHC analyses revealed that the number of CD8+ T cells in the TME was significantly increased after the neoadjuvant therapy (p<0.001). Notably, Tregs/CD8+ T cells ratio and the number of M2-macrophage in the TME were significantly decreased after the neoadjuvant therapy (p=0.032, 0.003, respectively). Conclusion: In the neoadjuvant therapy with pembrolizumab and ramucirumab, immune-activated status before treatment serves as a potential biomarker for predicting treatment response. Moreover, combining ramucirumab with pembrolizumab reduced immunosuppressive cells in the TME and inhibited tumor angiogenesis. These results suggest that this combination therapy modifies the TME and augments antitumor immunity. Larger clinical trial is warranted to assess the efficacy of neoadjuvant therapy with ramucirumab and pembrolizumab in patients with PD-L1-positive NSCLC. Citation Format: Kotaro Nomura, Shogo Kumagai, Shohei Koyama, Keiju Aokage, Yoshihisa Shimada, Kiyotaka Yoh, Masashi Wakabayashi, Miki Fukutani, Hideki Furuya, Tomohiro Miyoshi, Kenta Tane, Joji Samejima, Tetsuro Taki, Takuo Hayashi, Jun Matsubayashi, Genichiro Ishii, Norihiko Ikeda, Hiroyoshi Nishikawa, Masahiro Tsuboi. Biomarker analysis of pembrolizumab and ramucirumab neoadjuvant therapy for PD-L1-positive stage IB-IIIA lung cancer: EAST ENERGY trial [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(6_Suppl):Abstract nr 1211.