Comparison of cetuximab (Cmab) with panitumumab (Pmab) monotherapy in salvage line against KRAS wild-type patients with metastatic colorectal cancer (mCRC): Analysis of HGCSG0901 and 1002.

663 Background: Monoclonal antibodies targeting the epidermal growth factor receptor (EGFR) such as Cmab and Pmab have antitumor activity and acceptable safety profiles in patients (pts) with mCRC. Monotherapy with Cmab or Pmab demonstrated the effectiveness in salvage-line, and the direct comparison was reported in ESMO 2013 (ASPECCT trial). Methods: Data of 31 pts with mCRC treated by monotherapy with Cmab (HGCSG0901) and 51 pts by monotherapy with Pmab (HGCSG1002) registered from 27 institutions in Japan. Comparison of Cmab with Pmab was retrospectively analyzed. All patients with KRAS wild type were refractory to or intolerant for 5-FU/irinotecan/oxaliplatin and also were never administered anti-EGFR-antibodies. Survival analyses were performed with Kaplan-Meier method, log-rank test, and Cox proportional hazards model. Results: Patient characteristics were as below (Cmab vs. Pmab); male/female 20/11 vs. 27/24, median age (range) 65(44-76) vs. 64(44-81), PS 0-1/2-3 21/10 vs. 46/5, number of metastatic...