Research presented at the 2026 American Association for Cancer Research (AACR) Immuno-Oncology Conference (AACR IO) highlights a potential new precision immunotherapy approach for EGFR-mutant non-small cell lung cancer (NSCLC), a disease that has historically shown limited response to immune checkpoint inhibitors (ICIs) and which eventually develops resistance to EGFR tyrosine kinase inhibitors (TKIs). Despite advances in targeted therapy, there are no established immune-based strategies to prevent the progression of early or preinvasive EGFR-mutant lung lesions, including subsolid ground-glass nodules (GGNs). This challenge constitutes a critical unmet need in lung cancer interception.
The study, presented by Yongfeng He, PhD, Assistant Professor of Cancer Biology Research within the Department of Cardiothoracic Surgery at Weill Cornell Medicine in New York City, was led by Vivek Mittal, PhD; Nasser Altorki, MD; and Timothy McGraw, PhD. Through whole- exome sequencing and RNA sequencing of more than 200 patients with early and invasive disease, they identified EGFR-L858R as a recurrent, naturally presented neoantigen across several common human leukocyte antigen (HLA) alleles in early lung cancer lesions. Because the mutation appears consistently, Dr. He and colleagues propose that it may represent a shared, targetable immunologic abnormality in EGFR-mutant disease for immune interception.
Building on this finding, the investigators developed several mutation-directed therapeutic strategies, including an mRNA-based lipid nanoparticle (LNP) vaccine designed to elicit an immune response against the EGFR-L858R mutation. In preclinical models, vaccination generated mutation-specific CD8-positive T-cell responses and suppressed tumor growth in a subset of mice.
Dr. He said the response appeared to depend on the tumor’s immune environment. Tumors that did not respond showed features associated with immune suppression, including enrichment of tumor-associated macrophages, suggesting that the immune context may influence treatment efficacy.
The researchers also developed bi-specific antibodies and TCR-mimic CAR-T cells that recognize the L858R mutation when presented by specific HLA alleles. Dr. He said these therapies are currently being evaluated in EGFR-mutant patient-derived organoids, xenografts, and humanized mouse models with matched HLA backgrounds to support preclinical-to-clinical translation.
Together, he said, the EGFR driver mutation, while essential for tumor development and progression, may also represent its own immunogenic Achilles’ heel. The findings position EGFR-L858R as a shared, druggable neoantigen in early lung cancer lesions and outline a potential translational pathway for mutation-directed immunotherapy in EGFR-mutant NSCLC, a population with limited responsiveness to immunotherapy to date.
