title: Biweekly cetuximab plus irinotecan as second-line chemotherapy for patients with irinotecan-refractory and KRAS wild-type metastatic colorectal cancer according to epidermal growth factor receptor expression status.
abstract: BACKGROUND
  Cetuximab plus irinotecan has been shown to be effective in metastatic colorectal cancer (mCRC) patients with wild-type (WT) KRAS and positive EGFR expressions (EGFR+). Retrospective analysis revealed that the efficacy of cetuximab was similar in mCRC patients negative (EGFR-) and positive for EGFR. However, the efficacy of cetuximab has not been assessed prospectively in EGFR- mCRC patients.
  
  
  METHODS
  This was a prospective, multicenter phase II study assessed the efficacy and safety of biweekly cetuximab (500 mg/m(2)) and irinotecan (150-180 mg/m(2)) in patients with histologically proven adenocarcinoma with WT-KRAS and measurable lesion(s), either EGFR + or EGFR-, determined immunohistochemically, who failed first-line irinotecan-containing chemotherapy. The primary endpoint was response rate (RR), and the secondary endpoints included safety, progression-free survival (PFS) and overall survival (OS).
  
  
  RESULTS
  Forty patients were enrolled; 20 EGFR + and 20 EGFR-; their baseline characteristics were balanced. The overall RR was 45% (18/40, 95% CI 29.6-60.4), 55% (11/20) in EGFR + and 35% (7/20) in EGFR- patients. Median PFS was 7.1 months (95% CI 4.8-9.4), 8.3 months in EGFR + and 4.9 months in EGFR- patients. Median OS was 18.5 months (95% CI 15.2-21.8), 17.2 months in EGFR + and 18.5 months in EGFR- patients. Grade 3 or 4 toxicities included neutropenia in 5 patients (12.5%) and febrile neutropenia/skin rash/asthenia in 2 (5%).
  
  
  CONCLUSIONS
  Biweekly cetuximab plus irinotecan as second-line treatment showed significant anti-tumor activity in patients with irinotecan-refractory mCRC and WT-KRAS regardless of EGFR expression status.
authors.affiliation: Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, 86 Asanbyeongwon-gil, Songpa-gu, Seoul, Korea.
authors.forename: Myoung Joo
authors.initials: MJ
authors.lastname: Kang
authors.forename: Yong Sang
authors.initials: YS
authors.lastname: Hong
authors.forename: Kyu-pyo
authors.initials: KP
authors.lastname: Kim
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Kim
authors.forename: Ji Yeon
authors.initials: JY
authors.lastname: Baek
authors.forename: Min-Hee
authors.initials: MH
authors.lastname: Ryu
authors.forename: Jae-Lyun
authors.initials: JL
authors.lastname: Lee
authors.forename: Heung Moon
authors.initials: HM
authors.lastname: Chang
authors.forename: Mi-Jung
authors.initials: MJ
authors.lastname: Kim
authors.forename: Hee Jin
authors.initials: HJ
authors.lastname: Chang
authors.forename: Yoon-Koo
authors.initials: YK
authors.lastname: Kang
authors.forename: Tae Won
authors.initials: TW
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D002166:Camptothecin / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000068818:Cetuximab; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000473:pathology; D004334:Drug Administration Schedule; D019008:Drug Resistance, Neoplasm; D066246:ErbB Receptors / Q000378:metabolism*; D005260:Female; D006801:Humans; D000077146:Irinotecan; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D016283:Proto-Oncogene Proteins p21(ras); D016896:Treatment Outcome; D055815:Young Adult; D018631:ras Proteins / Q000235:genetics*
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; D000077146:Irinotecan; D066246:ErbB Receptors; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins; D000068818:Cetuximab; D002166:Camptothecin