Comparison of adding cetuximab (Cmab) or panitumumab (Pmab) to irinotecan (IRI)-based chemotherapy in salvage line against KRAS wild-type patients with metastatic colorectal cancer (mCRC): Analysis of HGCSG0901 and 1002.

598 Background: Cmab and Pmab have antitumor activity and acceptable safety profiles in patients (pts) with mCRC. Although IRI-based chemotherapy combined with Cmab or Pmab has demonstrated the effectiveness in salvage-line, there has been no reported trials comparing these antibodies directly. Methods: Data of 96 pts with mCRC treated by Cmab plus IRI-based chemotherapy (Cmab/IRI) from HGCSG 0901 and 27 pts treated by Pmab plus IRI-based chemotherapy (Pmab/IRI) from HGCSG1002 were 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/IRI vs. Pmab/IRI); male/female 58/38 vs. 16/11, median age (range) 63(38-80) vs. 64(49-81), PS 0/1/2 52/35/9 vs. 21/6/0, number of metastatic organs 1/2/3- 29/37/30 vs. 6/12/7, prior bevaciz...