Advanced bladder cancer (BCa) is associated with a poor prognosis, highlighting the urgent need for novel therapeutic strategies with improved efficacy and reduced toxicity. Nectin-4 (PVRL4, here after referred to as N4) is a clinically validated therapeutic target; however, existing antibody-based agents are limited by inadequate tumor penetration and off-target toxicities. Nanobodies (Nbs) possess favorable characteristics, including small molecular size, enhanced tissue penetration, and ease of sengineering. This study aimed to identify and preliminarily characterize N4-targeting Nb candidates for BCa using a yeast surface display-based screening strategy. N4 was highly expressed in BCa and significantly associated with an unfavorable prognosis. The YSD platform supported efficient library expansion, surface display, and iterative enrichment of N4-binding clones. Among the identified Nbs, Nb-80 exhibited apparent binding activity, with an EC₅₀ of 0.150 μg/mL. BLI analysis demonstrated rapid association–dissociation kinetics. An N4-binding Nb candidate was identified and preliminarily characterized using a YSD-based screening strategy. These findings support the utility of the YSD platform for Nb discovery and provide a preliminary basis for further validation of N4-targeting Nb candidates in BCa. Not applicable.
Wen et al. (Sat,) studied this question.