FDA Approves Tecentriq (Atezolizumab) + Chemotherapy for Stage III dMMR Colon Cancer — Disease-Free Survival HR 0.50 in ATOMIC
October 8, 2026. The FDA approved atezolizumab (Tecentriq, Genentech) in combination with a fluoropyrimidine and oxaliplatin "for the adjuvant treatment of adult and pediatric patients two years of age and older with Stage III mismatch repair deficient (dMMR) colon cancer12." The agency simultaneously approved the subcutaneous presentation, atezolizumab and hyaluronidase-tqjs (Tecentriq Hybreza), for patients 12 years and older weighing ≥40 kg with Stage III dMMR colon cancer. The review was conducted under Project Orbis (with Australia's TGA, Health Canada, Israel's ImoH, and Swissmedic — other agencies' reviews ongoing) and granted priority review.
The evidence: ATOMIC
Efficacy came from ATOMIC/ML39057 (NCT02912559), a multicenter, randomized, open-label, active-controlled trial in 711 adults and one pediatric patient with Stage III dMMR colon cancer after complete resection. Patients got either atezolizumab + mFOLFOX6 for 12 cycles followed by atezolizumab monotherapy for 6 months, or mFOLFOX6 alone for 12 cycles. The major outcome, investigator-assessed disease-free survival:
"The hazard ratio for the DFS comparison was 0.50 (95% CI: 0.35, 0.73; p-value 0.0001), and the median DFS was not reached (NR) in either arm."
A hazard ratio of 0.50 means the atezolizumab regimen halved the risk of recurrence or death in the adjuvant (curative-intent) setting — a large effect for a post-surgical therapy. The approved schedule is 840 mg IV every 2 weeks (or 1200 mg q3w / 1680 mg q4w) with chemo for 6 months, then atezolizumab alone for another 6 months or until recurrence/unacceptable toxicity.
What it means
This brings PD-L1 checkpoint inhibition into the adjuvant treatment of dMMR colon cancer, a tumor type defined by mismatch-repair deficiency (microsatellite instability) — the biology that predicts immunotherapy responsiveness. The label spans adults and children down to age 2, which is unusual for an oncology approval and reflects the trial's pediatric inclusion. Label warnings cover the standard immune-mediated adverse reactions, infusion reactions, complications of allogeneic hematopoietic stem-cell transplantation, and embryo-fetal toxicity.
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An instance of Every approved drug is on a one-way ratchet toward first-line use. — Checkpoint blockade moves into the curative-intent post-surgical setting to halve recurrence risk, widening the label toward universal early use rather than defending a metastatic foothold. ↩︎
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An instance of Oncology blockbusters must target adjuvant settings to secure massive patient volumes. — Checkpoint inhibition is being pushed into the post-surgical adjuvant setting, halving recurrence risk in the large curative-intent population. ↩︎