FDA Approves IV, Subcutaneous Atezolizumab for dMMR Colon Cancer

The FDA approved atezolizumab (Tecentriq; Genentech) in combination with a fluoropyrimidine and oxaliplatin for the adjuvant treatment of adult and pediatric patients 2 years of age and older with stage III mismatch repair deficient (dMMR) colon cancer.¹ The approval was announced October 8, 2026.

The agency also approved a subcutaneous formulation, atezolizumab and hyaluronidase-tqjs (Tecentriq Hybreza; Genentech), for use with the same chemotherapy backbone. It is indicated for adult and pediatric patients 12 years of age and older who weigh at least 40 kg. The subcutaneous product is given as a single injection rather than an intravenous infusion, offering a different route of administration for the same indication.

Phase 3 ATOMIC Trial Supports Approval

The approval rests on ATOMIC/ML39057 (NCT02912559), a multicenter, randomized, open-label, active-controlled phase 3 trial that enrolled 711 adults and 1 pediatric patient with Stage III dMMR colon cancer.² Participants had undergone complete resection of the primary tumor and had no evidence of residual lymph node involvement or metastatic disease.

Patients were randomized 1:1 to atezolizumab plus modified FOLFOX6 (mFOLFOX6; oxaliplatin, leucovorin, and fluorouracil) for 12 cycles, followed by 6 months of atezolizumab monotherapy, or to mFOLFOX6 alone for 12 cycles. The active-controlled design allowed a direct comparison of what atezolizumab adds to chemotherapy alone.

The major efficacy outcome was investigator-assessed disease-free survival (DFS). Adding atezolizumab to chemotherapy produced a DFS hazard ratio of 0.50 (95% CI, 0.35-0.73; P = .0001), corresponding to a 50% lower hazard of a DFS event than with chemotherapy alone. Median DFS was not reached in either arm.

In the peer-reviewed ATOMIC publication, 3-year DFS was 86.3% with atezolizumab plus mFOLFOX6 vs 76.2% with mFOLFOX6 alone, at a median follow-up of 40.9 months. Overall survival did not differ significantly between arms (hazard ratio, 0.90; 95% CI, 0.55-1.47; P = .68), with 5-year rates of 89.7% and 87.9%.

The prescribing information carries warnings and precautions for immune-mediated adverse reactions, infusion-related reactions, complications of allogeneic hematopoietic stem cell transplantation, and embryo-fetal toxicity.¹ Grade 3 or higher adverse events occurred in 84.1% of patients receiving the combination and 71.9% of those receiving mFOLFOX6 alone, and 2 treatment-related deaths occurred in the combination arm.²

Dosing Differs by Age and Formulation

For adults, the recommended intravenous atezolizumab dose is 840 mg every 2 weeks, 1200 mg every 3 weeks, or 1680 mg every 4 weeks.¹ It is given with chemotherapy for 6 months, followed by atezolizumab alone for 6 months or until disease recurrence or unacceptable toxicity. Pediatric patients receive 10 mg/kg (up to 840 mg) every 2 weeks or 15 mg/kg (up to 1200 mg) every 3 weeks on the same schedule.

The subcutaneous formulation is given as a single 15 mL injection every 3 weeks, containing 1875 mg of atezolizumab and 30,000 units of hyaluronidase, followed by the same 6-month monotherapy phase. Dosing has not been established for pediatric patients younger than 12 years or for those 12 years and older who weigh less than 40 kg.

Review Conducted Through Project Orbis

The applications received priority review under Project Orbis, an FDA Oncology Center of Excellence initiative that allows concurrent review of oncology drugs among international partners. The FDA collaborated with the Australian Therapeutic Goods Administration, Health Canada, Israel’s Ministry of Health, and Switzerland’s Swissmedic, and reviews remain ongoing at those agencies. The review also used the Assessment Aid, a voluntary applicant submission intended to facilitate the FDA’s assessment.

References

1. FDA approves atezolizumab in combination with chemotherapy for Stage III mismatch repair deficient colon cancer. FDA. October 8, 2026. Accessed October 8, 2026. https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-atezolizumab-combination-chemotherapy-stage-iii-mismatch-repair-deficient-colon-cancer
2. Sinicrope FA, Ou FS, Arnold D, et al. Atezolizumab plus FOLFOX for stage III mismatch repair-deficient colon cancer. N Engl J Med. 2026;394(12):1155-1166. doi:10.1056/NEJMoa2507874