Background: Adoptive cellular therapy (ACT) has dramatically changed the landscape of immunotherapy. T-cell receptor (TCR) engineered ACT approach has contributed to success in solid tumors. ACTengine IMA201 is a product based on autologous T cells engineered to express a naturally occurring TCR specific to a cancer-germline peptide. The target peptide has been characterized in depth by Immatics’ proprietary antigen discovery platform, XPRESIDENT showing exceptional specificity, copy number and expression homogeneity. XPRESIDENT has applied two independent methodologies to confirm the selectivity of tumor target: i) ultra-sensitive quantitative immunopeptidome analyses by mass spectrometry and ii) quantitative mRNA expression analyses by RNASeq. Immatics´ TCR discovery platform is optimized to identify TCRs with low micromolar affinity, specific recognition of tumor cell lines and lack of recognition of healthy normal cells. Methods: This study is an open-label first-in-human dose-escalating phase I trial investigating safety, tolerability and clinical activity in end-stage solid tumor patients. Key eligibility criteria include: recurrent or refractory squamous non-small cell lung cancer or head and neck squamous cell cancer, HLA-A*02:01 phenotype, qPCR biomarker positive from a tumor biopsy, prior established lines of therapy, RECIST v1.1 measurable lesions and ECOG score 0 or 1. At baseline, patients will undergo leukapheresis to collect mononuclear cells (PBMC). The activated PBMC will be transduced with a lentiviral vector for manufacturing of IMA201. IMA201 is infused after a pre-conditioning (lymphodepletion) followed by LD-IL2. The primary objective is to assess safety and to identify the maximum tolerated dose. Secondary endpoints include overall response rate (RECIST and irRC), PFS and OS. The translational objectives include: i) the persistence and functionality of IMA201 in vivo, ii) correlative biomarkers for clinical success, and iii) target expression levels in the tumor. Enrollment to the study is currently ongoing. Clinical trial information: NCT03247309.