YL252

YL252 is a dual-functional antibody-drug conjugate (ADC) developed by MediLink Therapeutics that simultaneously targets Programmed Death-Ligand 1 (PD-L1) and Vascular Endothelial Growth Factor (VEGF). It is constructed using MediLink's proprietary Tumor Microenvironment-Activable Linker (TMALIN) platform, which incorporates a protease-cleavable tripeptide linker and a novel DNA topoisomerase I inhibitor payload. YL252 is designed to integrate three distinct therapeutic mechanisms: immunotherapy (by blocking PD-L1 signaling to modulate immune suppression), anti-angiogenesis (by sequestering soluble VEGF), and cytotoxicity (via the targeted delivery of the topoisomerase I inhibitor). In nonclinical studies, YL252 demonstrated efficient internalization, potent cytotoxicity, and strong bystander effects in PD-L1-expressing tumor cells. Xenograft models showed dose-dependent tumor growth inhibition and complete regressions without detectable toxicity, supported by a favorable safety profile in cynomolgus monkeys with a therapeutic index of approximately 100.