{"entity":{"id":"mountaineer-03","kind":"trial","name":"MOUNTAINEER-03","aka":[],"tldr":"The trial that will decide whether HER2 drugs belong in the first treatment for HER2-positive bowel cancer rather than after chemotherapy has failed.","summary":"MOUNTAINEER-03 is the randomised phase 3 successor to the single-arm MOUNTAINEER cohorts that won tucatinib plus trastuzumab its accelerated approval on 19 January 2023. It randomises about 400 patients with previously untreated HER2-positive, RAS wild-type metastatic colorectal cancer to tucatinib and trastuzumab with mFOLFOX6, or to mFOLFOX6 with bevacizumab or cetuximab at the investigator's choice. The registry records a start date of 24 October 2022, recruitment continuing and primary completion due 31 December 2027, so the confirmatory evidence for the accelerated approval is several years away. Until then HER2-directed treatment in colorectal cancer is a later-line option and HER2 testing is not yet required at diagnosis everywhere.","status":"recruiting","asOf":"2026-09-24","links":[{"label":"ClinicalTrials.gov NCT05253651","url":"https://clinicaltrials.gov/study/NCT05253651"},{"label":"MOUNTAINEER: tucatinib plus trastuzumab for chemotherapy-refractory HER2-positive RAS wild-type metastatic colorectal cancer (Lancet Oncology 2023)","url":"https://doi.org/10.1016/S1470-2045(23)00150-X"}],"tags":[],"related":[],"cancers":["colorectal","her2-amplified-colorectal"],"sections":[],"technologies":["her2-tyrosine-kinase-inhibitors","monoclonal-antibody","kinase-inhibitors"],"targets":["her2"],"drugs":["tucatinib","trastuzumab","folfox","bevacizumab","cetuximab","oxaliplatin"],"companies":["pfizer"],"institutions":[],"pathways":[],"terms":[],"trials":["mountaineer","destiny-crc02"],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"nct":"NCT05253651","phase":"3","setting":"First-line HER2-positive, RAS wild-type metastatic colorectal cancer: tucatinib with trastuzumab and mFOLFOX6 against mFOLFOX6 with bevacizumab or cetuximab","sponsor":"Seagen, a wholly owned subsidiary of Pfizer","yearReported":2027,"enrolled":400,"enrolledBasis":"registry","outcomes":[]},"route":"/trials/mountaineer-03/","neighbours":{"cancer":[{"id":"colorectal","kind":"cancer","name":"Colorectal cancer","route":"/cancers/colorectal/"},{"id":"her2-amplified-colorectal","kind":"cancer","name":"HER2-amplified colorectal cancer","route":"/cancers/her2-amplified-colorectal/"}],"technology":[{"id":"her2-tyrosine-kinase-inhibitors","kind":"technology","name":"HER2 tyrosine kinase inhibitors","route":"/technologies/her2-tyrosine-kinase-inhibitors/"},{"id":"monoclonal-antibody","kind":"technology","name":"Monoclonal antibodies","route":"/technologies/monoclonal-antibody/"},{"id":"kinase-inhibitors","kind":"technology","name":"Small-molecule kinase inhibitors","route":"/technologies/kinase-inhibitors/"}],"target":[{"id":"her2","kind":"target","name":"HER2","route":"/targets/her2/"}],"drug":[{"id":"bevacizumab","kind":"drug","name":"Bevacizumab","route":"/drugs/bevacizumab/"},{"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/"},{"id":"trastuzumab","kind":"drug","name":"Trastuzumab","route":"/drugs/trastuzumab/"},{"id":"tucatinib","kind":"drug","name":"Tucatinib","route":"/drugs/tucatinib/"}],"company":[{"id":"pfizer","kind":"company","name":"Pfizer (incl. Seagen)","route":"/companies/pfizer/"}],"trial":[{"id":"destiny-crc02","kind":"trial","name":"DESTINY-CRC02","route":"/trials/destiny-crc02/"},{"id":"mountaineer","kind":"trial","name":"MOUNTAINEER","route":"/trials/mountaineer/"}]}}