Mechanistic Insights into Anti-Nectin4-VcMMAE-Induced Ocular Toxicity: From Cellular Uptake Pathways to Molecular Modification

Antibody-drug conjugates (ADCs) represent a novel approach to cancer treatment. Enfortumab vedotin (PADCEV), as a prominent example, has demonstrated remarkable clinical efficacy. However, its ocular toxicity has raised concerns. This study aimed to explore the molecular mechanisms underlying PADCEV-induced ocular toxicity. SD rats, whose ocular structures are similar to those of humans, were selected to establish an ocular toxicity model to mimic the human response. In vitro experiments were conducted using human primary corneal epithelial cells, HCE-T. The results confirmed that nectin-4 plays a crucial role in the cellular uptake of PADCEV, and non-specific pinocytosis is also involved. Additionally, a variant was obtained by introducing point mutations in the Fc region of PADCEV, which was found to reduce corneal epithelial toxicity. The findings of this study not only deepen our understanding of ADC-induced ocular toxicity but also provide new insights into optimizing ADC design and enhancing treatment safety.