FDA accepts immunotherapy drug for review in colon cancer treatment

The Alliance for Clinical Trials in Oncology (Alliance) today announced that the U.S. Food and Drug Administration has accepted for review Genentech's supplemental Biologic License Application for their immunotherapy drug atezolizumab (Tecentriq^®) for the treatment of patients with stage III colon cancer with deficient deoxyribonucleic acid (DNA) mismatch repair (dMMR). The application is supported by findings from the phase III Alliance ATOMIC (A021502) trial, sponsored by the National Cancer Institute (NCI) and conducted in partnership with Genentech, a member of the Roche Group, and the German group Arbeitsgemeinschaft Internistische Onkologie (AIO). The study demonstrated that patients experienced significantly improved outcomes when atezolizumab was added to standard chemotherapy following surgery.

The FDA's acceptance of the application represents an important milestone for the clinical research community and reflects the potential impact of the ATOMIC trial on the treatment landscape for patients with a molecularly defined subtype of early-stage colon cancer. The FDA is expected to decide on the approval by October 2026.

The acceptance of this application underscores the promise of personalized biomarker-driven approaches in increasing cures for patients with cancer and the commitment of the patients, caregivers, investigators, and research staff who participated in the ATOMIC trial. It is gratifying to see findings generated through a National Cancer Institute-funded cooperative research effort result in a regulatory review that could ultimately expand treatment options for patients with colon cancer."

Evanthia Galanis, MD, DSc, Group Chair of the Alliance for Clinical Trials in Oncology

The ATOMIC trial enrolled 712 participants from September 2017 through January 2023 across the United States and Germany, evaluating adjuvant treatment strategies for stage III colon cancer with dMMR. The study examined whether adding atezolizumab to standard chemotherapy could improve outcomes in this biologically distinct population. Findings recently published in The New England Journal of Medicine showed that this approach reduced the risk of cancer recurrence or death by 50%, with 86.3% of patients remaining disease-free at three years compared with 76.2% receiving chemotherapy alone. These results represent the first demonstrated benefit of immunotherapy in early stage dMMR colon cancer.

"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 Alliance Study Chair Frank A. Sinicrope, MD, Professor of Oncology and Clinical Investigator of the Mayo Foundation at the Mayo Clinic Comprehensive Cancer Center. "The FDA's acceptance reflects the strength of the data and the dedication of everyone involved in bringing this research to completion."

The trial was designed with disease-free survival as the primary endpoint, while overall survival and safety were designated as secondary endpoints. This design enabled a comprehensive assessment of both the efficacy and safety of integrating immunotherapy into the adjuvant treatment of stage III dMMR colon cancer.

Colorectal cancer remains a leading cause of cancer-related death worldwide. For patients with stage III colon cancer, the standard adjuvant treatment has long been chemotherapy with 5-FU-based therapy and oxaliplatin, such as the FOLFOX regimen. While these treatments have improved outcomes, many patients remain at risk of recurrence, underscoring the need for more effective, biomarker-driven approaches such as those evaluated in ATOMIC.

The latest National Comprehensive Cancer Network Guidelines include the ATOMIC findings and extend consideration of this treatment approach to patients with stage II T4bN0 colon cancer-tumors that have grown outward locally but have not spread to lymph nodes or distant sites.

Alliance ATOMIC (A021502) trial is sponsored by the National Cancer Institute (NCI), part of National Institutes of Health, led by Alliance and conducted in the NCI funded National Clinical Trials Network (NCTN). Genentech, a member of the Roche Group, provided support to the study through a Cooperative Research and Development Agreement with the NCI.