Authors:

Jifang Gong¹, Ning Li², Weijian Guo³, Jian Zhang⁴, Hongli Li⁵, Fuyou Zhao⁶, Wei Li⁷, Meili Sun⁸, Zhenzhong Xia⁹, Yu Shen⁹, Jianming Wang⁹, Lingmin Lu⁹, Chuan Qi⁹, Xueming Qian⁹, Michael Shi⁹, Lin Shen¹;

¹Department of Gastrointestinal Oncology, Peking University Cancer Hospital and Institute, Beijing, China; ²Henan Cancer Hospital, Zhengzhou, China; ³Department of Medical Oncology, Fudan University Shanghai Cancer Center, Shanghai, China; ⁴Phase I Clinical Trial Center, Fudan University Shanghai Cancer Center, Shanghai, China; ⁵Tianjin Medical University Cancer Institute and Hospital, Tianjin, China; ⁶The First Affiliated Hospital, Bengbu Medical College, Bengbu, China; ⁷The First Hospital of Jilin University, Jilin, China; ⁸Jinan Central Hospital Affiliated to Shandong University, Jinan, China; ⁹Suzhou Transcenta Therapeutics Co., Ltd

Background:

• TST001 is a recombinant humanized IgG1 antibody specifically against human Claudin18.2 (CLDN18.2) with high affinity and enhanced FcR engaging of NK cell.

• In vivo pharmacology of TST001 in gastric PDX tumor model with CLDN18.2 medium expression: TST001 dose dependently inhibits tumor growth, TST001 exhibits more potent antitumor activity than IMAB362-analog at the same dose (10mg/kg), and more mice reached tumor complete regression.

• TST001 monotherapy dose-escalation study has been completed in China and promising anti-tumor activities were observed in patients with advanced G/GEJC with CLDN18.2 expression who had failed multiple lines of prior therapies.

Conclusion and Future Directions for Research:

• TST001 in combination with CAPOX as the first line treatment of patients with advanced and metastatic G/GEJ cancer is well tolerated and encouraging preliminary anti-tumor activities have been observed.

• The recruitment for the current cohort is ongoing and the safety and efficacy of the combination of TST001+CAPOX as first line treatment for patients with advanced and metastatic G/GEJ cancer will be further evaluated.