1. Academic Validation
  2. Tumor-selective blockade of CD47 signaling with a CD47/PD-L1 bispecific antibody for enhanced anti-tumor activity and limited toxicity

Tumor-selective blockade of CD47 signaling with a CD47/PD-L1 bispecific antibody for enhanced anti-tumor activity and limited toxicity

  • Cancer Immunol Immunother. 2021 Feb;70(2):365-376. doi: 10.1007/s00262-020-02679-5.
Yan Wang 1 2 3 Haiqing Ni 4 Shuaixiang Zhou 4 Kaijie He 4 Yarong Gao 4 Weiwei Wu 4 Min Wu 4 Zhihai Wu 4 Xuan Qiu 4 Ying Zhou 4 Bingliang Chen 4 Donghui Pan 2 Chenrong Huang 1 3 Mingzhu Li 2 Yicong Bian 1 3 Min Yang 5 Liyan Miao 6 7 Junjian Liu 8
Affiliations

Affiliations

  • 1 Department of Clinical Pharmacology, First Affiliated Hospital of Soochow University, 899 Pinghai Road, Gusu District, Suzhou, 215006, Jiangsu Province, China.
  • 2 NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, 20 Qianrong Road, Binhu District, Wuxi, 214063, Jiangsu Province, China.
  • 3 Institute for Interdisciplinary Drug Research and Translational Sciences, College of Pharmaceutical Sciences, Soochow University, Suzhou, China.
  • 4 Innovent Biologics (Suzhou) Co., Ltd., 168 Dongping Street, Suzhou Industrial Park, Suzhou, 215123, Jiangsu Province, China.
  • 5 NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, 20 Qianrong Road, Binhu District, Wuxi, 214063, Jiangsu Province, China. yangmin@jsinm.org.
  • 6 Department of Clinical Pharmacology, First Affiliated Hospital of Soochow University, 899 Pinghai Road, Gusu District, Suzhou, 215006, Jiangsu Province, China. miaolysuzhou@163.com.
  • 7 Institute for Interdisciplinary Drug Research and Translational Sciences, College of Pharmaceutical Sciences, Soochow University, Suzhou, China. miaolysuzhou@163.com.
  • 8 Innovent Biologics (Suzhou) Co., Ltd., 168 Dongping Street, Suzhou Industrial Park, Suzhou, 215123, Jiangsu Province, China. junjian.liu@innoventbio.com.
Abstract

CD47, an immune checkpoint receptor frequently unregulated in various blood and solid tumors, interacts with ligand SIPRα on innate immune cells, and conveys a "do not eat me" signal to inhibit macrophage-mediated tumor phagocytosis. This makes CD47 a valuable target for Cancer Immunotherapy. However, the therapeutic utility of CD47-SIRPα blockade monoclonal antibodies is largely compromised due to significant red blood cell (RBCs) toxicities and fast target-mediated clearance as a result of extensive expression of CD47 on normal cells. To overcome these limitations and further improve therapeutic efficacy, we designed IBI322, a CD47/PD-L1 bispecific antibody which attenuated CD47 activity in monovalent binding and blocked PD-L1 activity in bivalent binding. IBI322 selectively bound to CD47+PD-L1+ tumor cells, effectively inhibited CD47-SIRPα signal and triggered strong tumor cell phagocytosis in vitro, but only with minimal impact on CD47 single positive cells such as human RBCs. In addition, as a dual blocker of innate and adaptive immune checkpoints, IBI322 effectively accumulated in PD-L1-positive tumors and demonstrated synergistic activity in inducing complete tumor regression in vivo. Furthermore, IBI322 showed only marginal RBCs depletion and was well tolerated in non-human primates (NHP) after repeated weekly injections, suggesting a sufficient therapeutic window in future clinical development of IBI322 for Cancer treatment.

Keywords

Adaptive immunity; Bispecific antibody; IBI322; Immunotherapy; Innate immunity; Phagocytosis.

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