The Alliance for Clinical Trials in Oncology announced on June 11 that the U.S. Food and Drug Administration has accepted Genentech's supplemental Biologic License Application for atezolizumab (Tecentriq) to treat patients with stage III colon cancer with deficient DNA mismatch repair (dMMR). The application is based on findings from the phase III Alliance ATOMIC (A021502) trial, which was sponsored by the National Cancer Institute and conducted in partnership with Genentech and Germany’s Arbeitsgemeinschaft Internistische Onkologie.
The ATOMIC trial demonstrated that adding atezolizumab to standard chemotherapy after surgery significantly improved outcomes for this molecularly defined group of early-stage colon cancer patients. According to the Alliance, the FDA is expected to make a decision about approval by October 2026.
The ATOMIC study enrolled 712 participants between September 2017 and January 2023 across sites in the United States and Germany. The research examined whether adjuvant treatment strategies incorporating atezolizumab could improve outcomes for patients with dMMR stage III colon cancer. Recently published results showed that this approach reduced the risk of recurrence or death by half, with disease-free survival at three years reaching 86.3% compared to 76.2% among those who received chemotherapy alone.
"ATOMIC answered an important clinical question and generated evidence that has the potential to inform future treatment decisions for patients with non-metastatic dMMR colon cancer," said Frank A. Sinicrope, MD, Professor of Oncology at Mayo Clinic Comprehensive Cancer Center and Chair of the Alliance Study. "The FDA's acceptance reflects the strength of the data and the dedication of everyone involved in bringing this research to completion."
Colorectal cancer remains a leading cause of cancer-related death worldwide. Standard adjuvant treatment for stage III colon cancer typically includes chemotherapy regimens such as FOLFOX, but many patients remain at risk of recurrence despite these therapies. The National Comprehensive Cancer Network Guidelines now include consideration of immunotherapy-based approaches like those evaluated in ATOMIC for certain high-risk cases.
