The FDA has approved atezolizumab (Tecentriq) in combination with a fluoropyrimidine and oxaliplatin as adjuvant treatment for stage III mismatch repair-deficient (dMMR) colon cancer. The intravenous form is approved for patients aged 2 years and older, while the subcutaneous formulation (atezolizumab plus hyaluronidase, Tecentriq Hybreza) is approved for patients 12 years and older who weigh at least 88 lb.
The approval is supported by the ATOMIC/ML39057 trial, which randomized 711 patients with stage III dMMR colon cancer to receive either atezolizumab plus chemotherapy followed by atezolizumab monotherapy, or chemotherapy alone. The 3-year disease-free survival rate was 86% with atezolizumab versus 76% with chemotherapy alone, corresponding to a 50% reduction in the risk of disease recurrence or death.
Grade 3 or higher adverse events occurred more often in the atezolizumab arm (71.7% vs 62.1%), but the safety profile was consistent with the drugs' known effects. The prescribing information includes warnings for immune-mediated adverse reactions, infusion-related reactions, complications of allogeneic hematopoietic stem-cell transplantation, and embryo-fetal toxicity.