title: An open-label, single-arm study assessing safety and efficacy of panitumumab in patients with metastatic colorectal cancer refractory to standard chemotherapy.
abstract: BACKGROUND
  A phase 3 study demonstrated that panitumumab, a human monoclonal anti-epidermal growth factor receptor antibody, significantly prolonged progression-free survival versus best supportive care (BSC) in patients with chemorefractory metastatic colorectal cancer.
  
  
  METHODS
  This open-label extension study evaluated panitumumab monotherapy in BSC patients with radiographically documented disease progression in the phase 3 study. Patients received panitumumab 6 mg/kg every 2 weeks. The primary end point was safety; efficacy was also evaluated.
  
  
  RESULTS
  One hundred and seventy-six patients were randomly assigned to the BSC arm of the phase 3 study received >/=1 panitumumab dose in this extension study. Panitumumab was well tolerated. The most frequent treatment-related adverse events were skin toxic effects. Three (2%) patients had a grade 4 treatment-related adverse event. There were no infusion reactions. One (0.6%) patient had a complete response; 19 (11%) patients had a partial response; and 58 (33%) patients had stable disease. Median progression-free survival time was 9.4 [95% confidence interval (CI): 8.0-13.4) weeks. Median overall survival time was 6.3 (95% CI: 5.1-6.8) months. Anti-panitumumab antibodies were detected in 3 (4.2%) of 71 patients with a post-baseline sample.
  
  
  CONCLUSIONS
  These findings are comparable to those from the phase 3 study and support panitumumab monotherapy for chemorefractory colorectal cancer.
authors.affiliation: Digestive Oncology Unit, University Hospital Gasthuisberg, Leuven, Belgium.
authors.forename: E
authors.initials: E
authors.lastname: Van Cutsem
authors.forename: S
authors.initials: S
authors.lastname: Siena
authors.forename: Y
authors.initials: Y
authors.lastname: Humblet
authors.forename: J-L
authors.initials: JL
authors.lastname: Canon
authors.forename: J
authors.initials: J
authors.lastname: Maurel
authors.forename: E
authors.initials: E
authors.lastname: Bajetta
authors.forename: B
authors.initials: B
authors.lastname: Neyns
authors.forename: D
authors.initials: D
authors.lastname: Kotasek
authors.forename: A
authors.initials: A
authors.lastname: Santoro
authors.forename: W
authors.initials: W
authors.lastname: Scheithauer
authors.forename: S
authors.initials: S
authors.lastname: Spadafora
authors.forename: R G
authors.initials: RG
authors.lastname: Amado
authors.forename: N
authors.initials: N
authors.lastname: Hogan
authors.forename: M
authors.initials: M
authors.lastname: Peeters
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy / Q000401:mortality / Q000628:therapy*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000009:adverse effects / Q000627:therapeutic use*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000628:therapy*; D018450:Disease Progression; D018572:Disease-Free Survival; D003875:Drug Eruptions / Q000209:etiology; D019008:Drug Resistance, Neoplasm; D066246:ErbB Receptors / Q000037:antagonists & inhibitors* / Q000276:immunology; D005260:Female; D006801:Humans; D007167:Immunotherapy / Q000009:adverse effects / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000037:antagonists & inhibitors* / Q000276:immunology; D000077544:Panitumumab; D016879:Salvage Therapy / Q000706:statistics & numerical data; D016019:Survival Analysis