809 A bispecific antibody targeting CCR8 & CTLA-4: Potent anti-tumor efficacy with better safety by preferentially eliminating tumor-infiltrating regulatory T cells by Chao Wang, Yi Luo, Tianhang Zhai, Weifeng Huang, Shuang Dai, Shaogang Peng, Andy Tsun, Xiaoniu Miao, Liandi Chen