Design of High-Affinity Mini-Protein Drug Conjugates Targeting TROP2

Abstract Accurate and effective treatment of solid tumors has long been a core issue in cancer therapy. Antibody-drug conjugates (ADCs) represent a crucial breakthrough in precision oncology. Traditional ADCs rely on monoclonal antibodies generated through animal immunization, followed by screening, sequencing, and recombinant expressiona process that is experimentally complex and costly. In this study, we employed deep learning-based computational design methods to design mini-protein binders targeting the tumor-associated antigen TROP2. The designed TROP2 mini-protein binder exhibited high specificity and thermal stability. The binding affinity was optimized from 40.4 nM to 628 pM through partial diffusion. On this basis, we engineered the mini-protein binder by conjugating it with the microtubule inhibitor VcMMAE, thereby constructing mini-protein drug conjugates (MPDCs) that can specifically target and kill TROP2-positive tumor cells. A comprehensive assessment of the anti-tumor efficacy of these MPDCs was performed using cancer cell lines, organoid models, and mouse xenograft models.