22C12

22C12 is a fully humanized monoclonal antibody designed to target mono-ADP-ribosyltransferase-1 (ART1), an extracellular enzyme that is overexpressed in certain cancers, particularly EGFR-mutated non-small cell lung cancer (NSCLC). ART1 facilitates tumor progression by catalyzing the mono-ADP-ribosylation (MARylation) of proteins such as the epidermal growth factor receptor (EGFR), which enhances oncogenic signaling and contributes to tyrosine kinase inhibitor (TKI) resistance. Additionally, ART1 activity promotes an immunosuppressive tumor microenvironment by influencing macrophage infiltration and T-cell activity. By blocking ART1, 22C12 inhibits EGFR MARylation, reduces downstream signaling, and reinvigorates the anti-tumor immune response by increasing CD8+ tissue-resident memory T cells. Preclinical data suggest that 22C12 can act synergistically with TKIs like osimertinib to achieve superior tumor control.