Atezolizumab plus FOLFOX for Stage III Mismatch Repair-Deficient Colon Cancer.
Publication/Presentation Date
3-26-2026
Abstract
BACKGROUND: Standard adjuvant chemotherapy for stage III colon cancer consists of a fluoropyrimidine-plus-oxaliplatin regimen. Whether the addition of atezolizumab (an anti-programmed death ligand 1 agent) to a modified FOLFOX6 regimen (fluorouracil, oxaliplatin, and leucovorin; called mFOLFOX6) would improve outcomes in patients with stage III colon cancer with mismatch repair-deficient (dMMR) status is unclear.
METHODS: In a phase 3 trial, we randomly assigned, in a 1:1 ratio, patients with resected stage III dMMR tumors to receive either adjuvant atezolizumab plus mFOLFOX6 for 6 months, with atezolizumab continued as monotherapy (for a total of 12 months of therapy), or mFOLFOX6 alone for 6 months. The primary end point was disease-free survival. Secondary end points were overall survival and the adverse-event profile.
RESULTS: A total of 355 patients were assigned to receive atezolizumab plus mFOLFOX6 and 357 to receive mFOLFOX6 alone. The median age of the patients was 64 years, 55.1% were women, and 53.9% had tumors that were T4, N2, or both (indicating high risk). At a median follow-up of 40.9 months, the 3-year disease-free survival was 86.3% (95% confidence interval [CI], 81.8 to 89.8) in the atezolizumab-mFOLFOX6 group, as compared with 76.2% (95% CI, 70.9 to 80.6) in the mFOLFOX6 group (hazard ratio for disease recurrence or death, 0.50; 95% CI, 0.35 to 0.73; P< 0.001). Adverse events of grade 3 or 4 occurred in 84.1% of the patients who received atezolizumab plus mFOLFOX6 and in 71.9% of those who received mFOLFOX6 alone.
CONCLUSIONS: The addition of atezolizumab to mFOLFOX6 significantly improved disease-free survival among patients with stage III dMMR colon cancer. (Funded by the National Cancer Institute of the National Institutes of Health and Genentech; ATOMIC ClinicalTrials.gov number, NCT02912559.).
Volume
394
Issue
12
First Page
1155
Last Page
1166
ISSN
1533-4406
Published In/Presented At
Sinicrope, F. A., Ou, F. S., Arnold, D., Peters, W. R., Behrens, R. J., Lieu, C. H., Matin, K., Cohen, D. J., Potter, S. L., Nixon, A. B., Kottschade, L. A., Kathol, E., Frankel, W. L., Shergill, A., Hsu, D., Reinacher-Schick, A., Mehan, P., Gold, P. J., Khalil, M. F., Zemla, T., … Meyerhardt, J. A. (2026). Atezolizumab plus FOLFOX for Stage III Mismatch Repair-Deficient Colon Cancer. The New England journal of medicine, 394(12), 1155–1166. https://doi.org/10.1056/NEJMoa2507874
Disciplines
Medicine and Health Sciences
PubMedID
41880612
Department(s)
Department of Medicine, Hematology-Medical Oncology Division
Document Type
Article