{"entity":{"id":"atomic","kind":"trial","name":"ATOMIC (Alliance A021502)","aka":[],"tldr":"Adding a year of immunotherapy to chemotherapy after surgery halved recurrences in stage III colon cancers with a broken DNA spell-checker.","summary":"ASCO 2025 plenary: 3-year DFS 86.4% vs 76.6% (HR 0.50). The first phase 3 to show immunotherapy benefit in the adjuvant colon setting; establishes a new standard for the ~10-15% of stage III colon cancers that are dMMR. Whether chemotherapy is needed at all in this group (NICHE-2 logic) is the next question.","status":"positive","asOf":"2026-09-07","links":[{"label":"ClinicalTrials.gov NCT02912559","url":"https://clinicaltrials.gov/study/NCT02912559"},{"label":"ASCO 2025 LBA1","url":"https://ascopubs.org/doi/10.1200/JCO.2025.43.17_suppl.LBA1"}],"tags":[],"related":[],"cancers":["colorectal","msi-high-colorectal"],"sections":[],"technologies":["checkpoint-inhibitor"],"targets":[],"drugs":["atezolizumab","folfox"],"companies":["alliance-oncology"],"institutions":[],"pathways":[],"terms":["msi","neoadjuvant-adjuvant"],"trials":["n0147","petacc-8","idea-collaboration","nct05855200"],"people":[],"bottlenecks":[],"keyPapers":["paper-atomic-n-engl-j-med-2026"],"journals":[],"dependsOn":[],"notes":[],"nct":"NCT02912559","phase":"3","setting":"Resected stage III dMMR colon cancer: adjuvant FOLFOX + atezolizumab (12 months) vs FOLFOX","sponsor":"Alliance / NCI","result":"3-year DFS 86.4% vs 76.6%, HR 0.50.","started":"2017-10-16","startedType":"actual","yearReported":2025,"enrolled":712,"enrolledBasis":"registry","outcomes":[{"endpoint":"Disease-free survival at 3 years","primary":true,"unit":"percent","arms":[{"name":"FOLFOX + atezolizumab","n":355,"value":86.4},{"name":"FOLFOX","n":357,"value":76.6}],"hr":0.5,"ci":[0.34,0.72],"source":"https://ascopubs.org/doi/10.1200/JCO.2025.43.17_suppl.LBA1"}],"replication":"First and only randomised adjuvant IO trial in dMMR colon cancer; consistent in direction with NICHE-2 and the metastatic trials."},"route":"/trials/atomic/","neighbours":{"cancer":[{"id":"colon-cancer","kind":"cancer","name":"Colon cancer (adenocarcinoma of the colon)","route":"/cancers/colon-cancer/"},{"id":"colorectal","kind":"cancer","name":"Colorectal cancer","route":"/cancers/colorectal/"},{"id":"msi-high-colorectal","kind":"cancer","name":"Mismatch-repair deficient (MSI-high) colorectal cancer","route":"/cancers/msi-high-colorectal/"}],"technology":[{"id":"checkpoint-inhibitor","kind":"technology","name":"Immune checkpoint inhibitors","route":"/technologies/checkpoint-inhibitor/"}],"drug":[{"id":"atezolizumab","kind":"drug","name":"Atezolizumab","route":"/drugs/atezolizumab/"},{"id":"folfox","kind":"drug","name":"FOLFOX (5-FU, leucovorin, oxaliplatin)","route":"/drugs/folfox/"}],"company":[{"id":"alliance-oncology","kind":"company","name":"Alliance for Clinical Trials in Oncology","route":"/companies/alliance-oncology/"}],"term":[{"id":"msi","kind":"term","name":"Microsatellite instability (MSI-H) / mismatch repair deficiency (dMMR)","route":"/terms/msi/"},{"id":"neoadjuvant-adjuvant","kind":"term","name":"Neoadjuvant / adjuvant / perioperative","route":"/terms/neoadjuvant-adjuvant/"}],"trial":[{"id":"n0147","kind":"trial","name":"Alliance N0147","route":"/trials/n0147/"},{"id":"idea-collaboration","kind":"trial","name":"IDEA collaboration","route":"/trials/idea-collaboration/"},{"id":"petacc-8","kind":"trial","name":"PETACC-8","route":"/trials/petacc-8/"},{"id":"nct05855200","kind":"trial","name":"Study of Perioperative Dostarlimab in Participants With Untreated T4N0 or Stage III dMMR/MSI-H Resectable Colon Cancer","route":"/trials/nct05855200/"}],"paper":[{"id":"paper-atomic-n-engl-j-med-2026","kind":"paper","name":"Atezolizumab plus FOLFOX for Stage III Mismatch Repair-Deficient Colon Cancer","route":"/key-papers/paper-atomic-n-engl-j-med-2026/"}],"pairing":[{"id":"neoadjuvant-io-dmmr","kind":"pairing","name":"Neoadjuvant checkpoint inhibitor → surgery (or no surgery) in dMMR colorectal cancer","route":"/pairings/neoadjuvant-io-dmmr/"}],"roadmap":[{"id":"colorectal-roadmap","kind":"roadmap","name":"Colorectal cancer roadmap: from the adenoma-carcinoma sequence and the first screening trials to total mesorectal excision, oxaliplatin, RAS testing, immunotherapy for mismatch repair-deficient disease, ctDNA-guided treatment and organ preservation","route":"/roadmaps/colorectal-roadmap/"}]}}