A single-arm, multicenter, phase II study of panitumumab in combination with capecitabine/oxaliplatin in first line, wild-type KRAS metastatic colorectal cancer patients.

e14563 Background: Panitumumab(P) has shown activity in terms of response and survival in patients (pts) with all RAS wild-type (WT) metastatic colorectal cancer (mCRC). The activity and toxicity of oxaliplatin(O)- capecitabine(C) (capox) with P have been questioned by previous studies. Methods: Pts with exon 2 KRAS WT mCRC received first-line chemotherapy with the combination of O 130 mg/m2, C 2000 mg/m2 and P 9 mg/Kg, repeated every 3 weeks for at least 6 cycles or until disease progression (PD) or intolerable toxicity. The primary endpoint was objective response rate (ORR). According to Simon's 2-stage optimal design, assuming the expected ORR to be at least 60% and the minimum acceptable ORR 45%, 77 pts were required at the final step. Results: 78 pts were enrolled. Median age was 65.5 years, males 58%, females 42%, ECOG performance status0 (80%), 1 (19%) and 2 (1%). 44 pts (54%) completed 6 cycles. Most frequent reasons of discontinuation were PD (11 pts), toxicity (7 pts), pt refusal (7 pts) and ...