Yunshan Yang,1,2,* Xu Luo,3,* Li Dai,2,* Tong He,2 Siqi Luo,1 Yongjin Zhou,1 Haibin Wang,2 Zhiqiang Yan,2 Qian Wang,2 Xiangren Jin2 

1Clinical Medical College, Guizhou Medical University, Guiyang, Guizhou, People’s Republic of China; 2Department of Gastrointestinal Surgery, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou, People’s Republic of China; 3Outpatient Department, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Qian Wang; Xiangren Jin, Email Wangqian118@outlook.com; jinxiangren92@163.com

Abstract: Envafolimab is a novel inhibitor for programmed cell death protein-ligand 1 (PD-L1) that can be administered subcutaneously. It has been found to be effective and safe in the treatment of advanced high microsatellite unstable (MSI-H) / mismatch repair deficient (dMMR) solid tumors. Currently, the efficacy of programmed cell death protein-1 (PD-1) / programmed cell death protein-ligand 1 (PD-L1) inhibitors in the treatment of microsatellite stable (MSS) tumors is not clear. We report a case of advanced colon cancer with MSS metastases in bilateral clavicle, mediastinum, retroperitoneum, bilateral hilum, and left side of thoracic 11/12 vertebral body. After 8 months of Envafolimab treatment, there was a significant reduction in metastatic lesions. As of February 1st, 2024, the patient exhibited no significant adverse reactions. The current efficacy evaluation was the partial response (PR), and the overall survival (OS) was more than 12 months. Considering the safety and efficacy of Envafolimab observed in our case, we believe that Envafolimab may be a promising drug for the treatment of MSS metastatic colon cancer.

Keywords: colon cancer, Envafolimab, immunotherapy, case report