Preparation and preliminary evaluation of antibody-drug conjugates targeting canine PD-L1 using high/low affinity anti-PD-L1 antibodies and tumor microenvironment-responsive linkers
PAN Zhiyuan
REN Yule
XU Jin
ZHU Weifan
ZHUANG Huangzhen
GAO Tianyu
CHEN Yi
GUO Menghui
LIU Tao
WANG Chenguang
QIAN Weizhu
HOU Sheng
JI Lusha
LI Jun
SUN Ziqiao
WANG Xuekun
XIE Lei
ZHANG Dapeng
GUO Huaizu
GUO Qingcheng
Abstract：Immune checkpoint blockade therapies have made groundbreaking progress in human cancer treatment,but the development of immunotherapeutic drugs for canine tumors remains a significant chal-lenge.With the rise of the pet market and advancements in veterinary medical technology,the demand for antibody-drug conjugates(ADCs)targeting canine tumors is growing.However,research on ADCs targe-ting canine Programmed Death-Ligand 1(PD-L1)is still in its infancy,with issues such as drug resistance and insufficient therapeutic efficacy requiring further exploration,particularly the impact of different anti-body types and drug-to-antibody ratio(DAR)on novel ADC performance.This study pioneers the prepa-ration of two novel canine PD-L1-targeting ADCs by integrating high/low-affinity anti-canine PD-L1 mon-oclonal antibodies(A-mAb and T-mAb),tumor microenvironment-responsive linkers,and the next-gen-eration topoisomerase I inhibitor Dxd.Through controlled conjugation parameters,ADCs with distinct DAR values were successfully prepared.Subsequent characterization,stability analysis,binding activity,and cytotoxicity evaluation revealed that both ADCs exhibited well-controlled DAR values and favorable developability.DAR values and antibody types influenced ADC stability and activity,while both high-and low-affinity antibodies demonstrated dose-dependent cytotoxicity that intensified with increasing DAR val-ues.This study lays the foundation for developing PD-L1-targeting ADCs for canine tumors and provides candidate drugs for future caninized ADC development.
Keywords：antibody-drug conjugates(ADCs)canine tumorsimmunotherapyprogrammed death-ligand 1(PD-L1)drug-to-antibody ratio(DAR)
Publication Date：2026-02-25
Online Publishing Date：2026-08-28(First online date of this platform, not the publication date of the document)
Pages：12( 94-105 )