{"entity":{"id":"opus","kind":"trial","name":"OPUS","aka":[],"tldr":"The oxaliplatin companion to CRYSTAL. It confirmed that the EGFR antibody only works when KRAS is normal.","summary":"OPUS randomised 344 patients with EGFR-expressing metastatic colorectal cancer to FOLFOX4 with or without cetuximab. KRAS status was evaluable in 315 of them (93 percent) and 179 (57 percent) were wild-type; 11 of 309 KRAS and BRAF evaluable tumours carried a BRAF mutation, all in the KRAS wild-type group. In KRAS wild-type disease cetuximab improved progression-free survival (hazard ratio 0.567, p=0.0064) and response (odds ratio 2.551, p=0.0027). The trial was too small to judge BRAF. Together with CRYSTAL it made KRAS testing compulsory in 2008 and 2009, the first negative predictive biomarker in solid-tumour oncology.","status":"positive","asOf":"2026-09-24","links":[{"label":"ClinicalTrials.gov NCT00125034","url":"https://clinicaltrials.gov/study/NCT00125034"},{"label":"OPUS: efficacy according to biomarker status of cetuximab plus FOLFOX-4 as first-line treatment (Annals of Oncology 2011)","url":"https://doi.org/10.1093/annonc/mdq632"}],"tags":[],"related":[],"cancers":["colorectal"],"sections":[],"technologies":["monoclonal-antibody","cytotoxic-chemotherapy"],"targets":["egfr","kras","braf"],"drugs":["cetuximab","folfox","oxaliplatin"],"companies":["merck-kgaa"],"institutions":[],"pathways":[],"terms":[],"trials":["crystal-fire3","prime"],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"nct":"NCT00125034","phase":"2","setting":"First-line EGFR-expressing metastatic colorectal cancer: FOLFOX4 with or without cetuximab, analysed by KRAS and BRAF status","sponsor":"Merck KGaA","result":"In KRAS wild-type disease, progression-free survival hazard ratio 0.567 and response odds ratio 2.551 with cetuximab added.","yearReported":2011,"enrolled":344,"enrolledBasis":"registry","outcomes":[{"endpoint":"Progression-free survival (KRAS wild-type)","primary":true,"unit":"hazard ratio","arms":[{"name":"FOLFOX4 plus cetuximab","value":0.567},{"name":"FOLFOX4","value":1}],"hr":0.567,"p":"0.0064","source":"https://doi.org/10.1093/annonc/mdq632"}]},"route":"/trials/opus/","neighbours":{"cancer":[{"id":"colorectal","kind":"cancer","name":"Colorectal cancer","route":"/cancers/colorectal/"}],"technology":[{"id":"cytotoxic-chemotherapy","kind":"technology","name":"Cytotoxic chemotherapy","route":"/technologies/cytotoxic-chemotherapy/"},{"id":"monoclonal-antibody","kind":"technology","name":"Monoclonal antibodies","route":"/technologies/monoclonal-antibody/"}],"target":[{"id":"braf","kind":"target","name":"BRAF","route":"/targets/braf/"},{"id":"egfr","kind":"target","name":"EGFR","route":"/targets/egfr/"},{"id":"kras","kind":"target","name":"KRAS","route":"/targets/kras/"}],"drug":[{"id":"cetuximab","kind":"drug","name":"Cetuximab","route":"/drugs/cetuximab/"},{"id":"folfox","kind":"drug","name":"FOLFOX (5-FU, leucovorin, oxaliplatin)","route":"/drugs/folfox/"},{"id":"oxaliplatin","kind":"drug","name":"Oxaliplatin","route":"/drugs/oxaliplatin/"}],"company":[{"id":"merck-kgaa","kind":"company","name":"Merck KGaA (EMD Serono)","route":"/companies/merck-kgaa/"}],"trial":[{"id":"crystal-fire3","kind":"trial","name":"CRYSTAL & FIRE-3","route":"/trials/crystal-fire3/"},{"id":"co-17","kind":"trial","name":"NCIC CO.17","route":"/trials/co-17/"},{"id":"paradigm","kind":"trial","name":"PARADIGM","route":"/trials/paradigm/"},{"id":"prime","kind":"trial","name":"PRIME","route":"/trials/prime/"}],"biomarker":[{"id":"ras-wild-type","kind":"biomarker","name":"RAS wild-type (extended KRAS and NRAS testing)","route":"/biomarkers/ras-wild-type/"}]}}