Authors:

Lin Shen¹, Zengqing Guo², Jingdong Zhang³, Weijian Guo⁴, Meili Sun⁵, Nong Xu⁶, Chuan Qi⁷, Xuelian Zhu⁷, Lijuan Zhang⁷, Li Xu⁸, Caroline Germa⁸

1. Peking University Cancer Hospital; 2. Fujian Cancer Hospital; 3. Liaoning Cancer Hospital; 4. Fudan University Shanghai Cancer Center; 5. Jinan Central Hospital Affiliated to Shandong University ; 6. The First Affiliated Hospital of Medical School of Zhejiang University; 7. Suzhou Transcenta Therapeutics Co, Ltd. 8. Transcenta Therapeutics, Inc.  

Background:

Osemitamab , a humanized monoclonal antibody with improved affinity to claudin (CLDN) 18.2 and enhanced antibody-dependent cell-mediated cytotoxicity, has demonstrated great synergistic effect with anti-PD-1 antibody and chemotherapy in pre-clinical research. 

As checkpoint inhibitor plus chemotherapy is the current standard of care (SOC), we explored the combination of CLDN18.2 antibody osemitamab with this SOC in CLDN18.2 positive 1L G/GEJ (gastric/gastroesophageal junction) cancer.

Conclusions:

Updated data indicated that the combination of osemitamab plus nivolumab and CAPOX as first-line treatment for patients with G/GEJ cancer was safe and well tolerated. 

The addition of osemitamab to CAPOX and nivolumab as first-line treatment for patients with advanced or metastatic G/GEJ cancer leads to encouraging and durable anti-tumor activities, especially for patients with high/medium CLDN18.2 expression regardless of PD-L1 CPS when cross comparing to historical controls.