Cetuximab with oxaliplatin and capecitabine (CAPOX)in patients with metastatic colorectal cancer (mCRC) refractory to standard chemotherapy.

3669 Background: Cetuximab is an EGFR-targeting IgG monoclonal antibody that has demonstrated activity as single agent or in combination with irinotecan in patients with mCRC (pts) refractory to chemotherapy. Conceivably as a result of chemosenzitation, pts with irinotecan-refractory tumors are more likely to respond to the combination with irinotecan when compared to single agent cetuximab. In combination with 5FU/LV/Oxaliplatin, two recent trials reported the highest response rates ever achieved in 1-line treatment of mCRC. Aim of this study was to evaluate efficacy and toxicity of cetuximab in combination with oxaliplatin plus capecitabine in mCRC pts refractory to oxaliplatin.,Pts refractory to standard chemotherapy (incl. 5FU, oxaliplatin, and irinotecan in all pts) were assigned to treatment with cetuximab (400mg/m d1 followed by weekly 250mg/m) and CAPOX: oxaliplatin (70mg/m d1 and 8; qd22) plus capecitabine (2000 mg/m d1-14; qd22). All tumors showed EGFR expression by IHC. Pts with sensory neurotoxicity > grade 1 resulting from previous oxaliplatin treatment were excluded. Tumor assessment was performed 9-weekly.,Since Jan 04, 15 pts have been prospectively evaluated: 9m/6f, median ECOG PS 1 [0-2], median age 59 yrs [32-75]. No. of previous treatment lines: Two 9 pts, three 5 pts, four 1 pt. Pretreatment included 5FU, oxaliplatin and irinotecan in all pts., MMC and gefitinib in 4 pts each. In 1 pt treatment was stopped due to a grade 4 hypersensitivity reaction. Further NCI-CTC grade 3/4 toxicities were (15 pts): leukopenia 1 pt, sensory neuropathy 1 pt, skin 2 pts, diarrhea 1 pt. Efficacy analysis of 15 pts: PR 27%, SD 27% (4 pts each), PD 46%. Currently median PFS is 2.5 mos (0.25+-9.6), median overall survival is 5.5+ mos (0.6-10.9+) (7 pts ongoing).,Combination of Cetuximab plus CAPOX has significant clinical activity in patients with colorectal cancer refractory to standard chemotherapy. The observed toxicities allow treatment even in this group of heavily pretreated patients. These promising results are currently further evaluated in an expanded phase II setting. [Table: see text].