Abstract 3046: Anti-tumor efficacy of CKD-702 in EGFR TKI-resistant patient-derived xenograft model
Authors: Shin Jung-Young , Kim Min-Young , Lee Mi-Ran , Kim Jeong-Oh , Jeon Eun-Ju , Choi Ji Hye , Hong Soon-Ki , Park Kyu-Jin , Kang Jin Hyoung 
Published: September 2020

Background: c-MET is co-expressed with EGFR in approximately 70% of EGFR mutant-positive tumors. In addition, c-Met amplification was found in 10-20% of lung cancer patients with acquired tolerance to EGFR TKI, and c-Met overexpression was found in 14-69% of patients receiving EGFR TKI. CKD-702, a double antibody, is designed to simultaneously block both EGFR and c-MET expression.

Purpose: We evaluated the anti-tumor efficacy of CKD-702 with PDX model derived from lung adenocarcinoma patients.

Methods: We constructed the PDX model by transplanting surgical tissue from lung adenocarcinoma patient into NOD/SCID mice after the approval of research protocol in Seoul St. Mary's Hospital IRB. We confirmed the co-existence of activating EGFR mutation and c-MET amplification with PNAclamp and FISH methods. We also checked overexpression of EGFR and c-MET protein by immunohistochemistry.

Results: The characteristics of tumor tissue transplanted for PDX model were: 1) Korean, lung cancer with EGFR TKI chemotherapy failure confirmed c-MET amplification (&gt; 5 copies) and overexpression (IHC score 3+), 19del Positive EGFR mutation, 2) European lung adenocarcinoma, c-MET amplification (&gt; 2.5 copy) and overexpression (IHC score 3+) were confirmed, and L858R EGFR mutation positive tumor tumor confirmed. The anti-cancer efficacy of CKD-702 was reduced by more than 80% compared to the tumor size of the control group regardless of the concentration. In the CKD-702 20mg/kg group, there was no significant difference in the change in the overall tumor size until the time of disappearing or ending during drug administration. The %TGI was 93.6 and 97.5 according to the concentration of CKD-702, and the % TGD was 118.5 and 311.8, respectively. CKD-702 has a significantly higher tumor growth inhibitory effect regardless of the concentration, but the tumor growth retardation effect is 2.6 times different depending on the concentration. % TGI of CKD-702 20mg / kg group was similar to Hu8c4 group or Hu8c4 + Vectibix group. However, % TGD was 1.4 times higher than Hu8c4 group efficacy and 3.1 times higher than Hu8c4 + Vectibix group% TGD. Even after the completion of drug administration, tumor still remained at 47 days and 67 days in the CKD-702 10 mg/kg and 20 mg/kg groups, respectively. Although c-MET protein expression decreased during the administration of CKD-702, it was confirmed that c-MET protein expression increased again in tumor tissue at the time of tumor growth. Although the tumor size was rather large (605.6 ~ 816.2mm3), CKD-702 showed twice the tumor growth inhibition effect (% TGI: 32.8 vs. 68.1) and the tumor growth delay effect was 4.4 times higher depending on the drug concentration (% TGI: 2.8 vs 12.3).

Conclusion: Our data showed that CKD-702 have effective anti-tumor activity in EGFR TKI-resistant PDX model harboring both activating EGFR mutation and c-MET overexpression.

Citation Format: Jung-Young Shin, Min-Young Kim, Mi-Ran Lee, Jeong-Oh Kim, Eun-Ju Jeon, Ji Hye Choi, Soon-Ki Hong, Kyu-Jin Park, Jin Hyoung Kang. Anti-tumor efficacy of CKD-702 in EGFR TKI-resistant patient-derived xenograft model [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3046.