title: A phase II study for metabolic in vivo response monitoring with sequential 18FDG-PET-CT during treatment with the EGFR-monoclonal-antibody cetuximab in metastatic colorectal cancer: the Heidelberg REMOTUX trial.
abstract: BACKGROUND
  The epidermal growth factor receptor monoclonal antibody cetuximab has proven activity in metastatic colorectal cancer. To date, the mechanisms of action are not completely understood. Especially the impact on tumor glucose metabolism, or tumor vascularization remains largely unclear. The understanding of mechanisms such as early changes in tumor metabolism is of clinical importance since there may be a substantial influence on choice and sequence of drug combinations. Early signals of response to cetuximab may prove useful to identify patients having a relevant clinical treatment benefit. The objective of this trial is to evaluate the predictive relevance of the relative change in (18)F-Fluorodeoxyglucose tumor uptake for early clinical response during short-term single agent treatment with cetuximab. Early clinical response will be routinely measured according to the response evaluation criteria in solid tumors. Accompanying research includes cytokine immune monitoring and analysis of tumor proteins and tumor genes.
  
  
  METHODS
  The REMOTUX trial is an investigator-initiated, prospective, open-label, single-arm, single-center early exploratory predictive study. The first (18)F-FDG PET-CT is conducted at baseline followed by the run-in phase with cetuximab at days 1 and 8. At day 14, the second (18)F-FDG PET-CT is performed. Subsequently, patients are treated according to the Folfiri-cetuximab regimen as an active and approved first-line regimen for metastatic colorectal carcinoma. At day 56, clinical response is evaluated with a CT-scan compared to the baseline analysis. Tracer uptake is assessed using standardized uptake values (SUVs). The main hypothesis to be tested in the primary analysis is whether or not the relative change in the SUV from baseline to day 14 has any predictive relevance for early clinical response determined at day 56. Patients are followed until death from any cause or until 24 months after the last patient has ended trial treatment.
  
  
  CONCLUSIONS
  The aim of this trial is to evaluate metabolic changes in metastatic colorectal cancer during short-term single agent treatment with cetuximab and to analyse their potential of predicting early clinical response. This could be helpful to answer the question if early identification of patients not responding to cetuximab is possible.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT200811021020; EudraCT 200901327923.
authors.affiliation: National Center for Tumor Diseases, University Medical Center Heidelberg, Heidelberg, Germany. anne.berger@med.uni-heidelberg.de
authors.forename: Anne Katrin
authors.initials: AK
authors.lastname: Berger
authors.forename: Carl
authors.initials: C
authors.lastname: von Gall
authors.forename: Ulrich
authors.initials: U
authors.lastname: Abel
authors.forename: Stefan
authors.initials: S
authors.lastname: Delorme
authors.forename: Matthias
authors.initials: M
authors.lastname: Kloor
authors.forename: Jennifer
authors.initials: J
authors.lastname: Ose
authors.forename: Tim Frederik
authors.initials: TF
authors.lastname: Weber
authors.forename: Annika
authors.initials: A
authors.lastname: Stange
authors.forename: Georg Martin
authors.initials: GM
authors.lastname: Haag
authors.forename: Uwe
authors.initials: U
authors.lastname: Haberkorn
authors.forename: Florian
authors.initials: F
authors.lastname: Lordick
authors.forename: Dirk
authors.initials: D
authors.lastname: Jäger
mesh_terms: D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D000068818:Cetuximab; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000378:metabolism / Q000556:secondary; D066246:ErbB Receptors / Q000037:antagonists & inhibitors; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D006801:Humans; D008297:Male; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D011446:Prospective Studies; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics*
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D066246:ErbB Receptors; D000068818:Cetuximab