Genentech’s Tecentriq Receives FDA Approval for Adjuvant Treatment of Stage III dMMR Colon Cancer
Genentech, a member of the Roche Group (SIX: RO, ROP; OTCQX: RHHBY), announced that the U.S. Food and Drug Administration (FDA) has approved Tecentriq® (atezolizumab) and Tecentriq Hybreza® (atezolizumab and hyaluronidase-tqjs) in combination with a fluoropyrimidine and oxaliplatin chemotherapy for the adjuvant treatment of patients with stage III deficient mismatch repair (dMMR) colon cancer. The approval introduces an immunotherapy-based treatment option for patients with this specific tumor subtype following surgery and represents the twelfth U.S. indication for Tecentriq.
The decision is an important development in the treatment of stage III dMMR colon cancer, a form of the disease characterized by defects in the DNA mismatch repair system. These defects can lead to the accumulation of genetic mutations within tumor cells, potentially making them more recognizable to the immune system and more responsive to immunotherapy.
The newly approved treatment combines atezolizumab, an immune checkpoint inhibitor, with chemotherapy to address the risk of cancer recurrence following surgical removal of the tumor. The FDA’s decision is supported by findings from the Phase III ATOMIC clinical trial, which demonstrated that adding Tecentriq to modified FOLFOX6 (mFOLFOX6) chemotherapy reduced the risk of disease recurrence or death by 50% compared with chemotherapy alone.
The findings represent a significant advance for patients with stage III dMMR colon cancer, who can remain at considerable risk of recurrence even after surgery and standard postoperative chemotherapy.
New Treatment Option Addresses an Unmet Need in Stage III Colon Cancer
Stage III colon cancer is generally treated with surgery followed by adjuvant chemotherapy intended to eliminate remaining cancer cells and reduce the likelihood of the disease returning. However, outcomes can vary according to the molecular characteristics of the tumor, including whether the cancer has a deficient mismatch repair system.
Historically, adjuvant treatment approaches for stage III colon cancer have not routinely differed according to mismatch repair status. The approval of atezolizumab in combination with chemotherapy introduces a treatment strategy specifically supported by clinical evidence in patients with dMMR disease.
Levi Garraway, M.D., Ph.D., chief medical officer and head of Global Product Development at Genentech, highlighted the significance of the approval for patients at risk of recurrence.
“This approval provides a new adjuvant treatment option for people with stage III dMMR colon cancer who face a high risk of disease recurrence,” Garraway said. He added that Tecentriq combined with chemotherapy has the potential to become a new standard of care as the first approved immunotherapy-based regimen for this treatment setting.
The approval reflects growing interest in using tumor biology to guide cancer treatment decisions. By identifying patients whose tumors have specific molecular characteristics, clinicians can increasingly evaluate therapies that are designed to address the biological features of the disease rather than relying exclusively on conventional treatment approaches.
For patients with stage III dMMR colon cancer, the combination of immunotherapy and chemotherapy offers an additional strategy to reduce the risk of recurrence after surgery.
Phase III ATOMIC Trial Supports FDA Approval
The FDA approval is based on the Phase III ATOMIC clinical study, which evaluated atezolizumab in combination with mFOLFOX6 chemotherapy in patients with stage III dMMR colon cancer.
The trial’s findings were recently published in The New England Journal of Medicine. The study assessed whether incorporating immunotherapy into the postoperative treatment regimen could improve disease-free survival compared with mFOLFOX6 chemotherapy alone.
The results demonstrated a meaningful improvement in outcomes for patients receiving the combination regimen.
According to the study findings, adding Tecentriq to mFOLFOX6 reduced the risk of disease recurrence or death by 50% compared with chemotherapy alone. This reduction indicates that the addition of atezolizumab provided a substantial benefit in the trial population.
The study also reported a difference in 36-month disease-free survival between the two treatment groups.
- Tecentriq plus mFOLFOX6: 86% disease-free survival at 36 months.
- mFOLFOX6 chemotherapy alone: 76% disease-free survival at 36 months.
These results represent a 10-percentage-point difference in disease-free survival at the 36-month assessment.
Disease-free survival is an important endpoint in adjuvant cancer treatment because it measures the period during which patients remain free of disease recurrence following treatment. Improving this outcome is a key objective after surgery, particularly for patients whose cancer has a significant likelihood of returning.
The ATOMIC findings support the use of immunotherapy alongside chemotherapy to improve postoperative outcomes in this molecularly defined patient population.
The trial evaluated patients whose tumors were identified as dMMR through immunohistochemistry testing, including testing with the VENTANA® MMR RxDx Panel. Assessing mismatch repair status is important because it helps determine whether a patient’s tumor belongs to the specific group covered by the approved treatment.
The study’s safety findings were also consistent with the previously established safety profiles of Tecentriq and mFOLFOX6. This provides additional information for clinicians considering the combination regimen in the adjuvant setting.
Although the reported results demonstrate a substantial improvement in disease-free survival, treatment decisions will continue to depend on individual patient circumstances, tumor characteristics, clinical judgment and the relevant prescribing information.
Understanding dMMR Colon Cancer and the Role of Immunotherapy
DNA mismatch repair is a cellular mechanism responsible for identifying and correcting errors that occur when DNA is copied. When this repair system is deficient, genetic errors can accumulate, resulting in tumors with a high number of mutations.
Deficient mismatch repair is closely associated with microsatellite instability-high (MSI-H), another molecular characteristic used in the diagnosis and classification of certain cancers. Both dMMR and MSI-H status can provide important information about tumor biology and potential treatment responses.
In colon cancer, approximately 15% of patients have dMMR or MSI-H tumors, according to the information provided by Genentech. These tumors may be more likely to respond to immunotherapy because their elevated mutation burden can produce abnormal proteins that the immune system may recognize as targets.
Atezolizumab is an immune checkpoint inhibitor that targets programmed death-ligand 1 (PD-L1). By blocking PD-L1, the medicine is designed to help restore or enhance the immune system’s ability to recognize and attack cancer cells.
Cancer cells can use immune checkpoint pathways to evade immune surveillance. Blocking these pathways can help the immune system mount a more effective response against malignant cells.
Combining an immune checkpoint inhibitor with chemotherapy brings together two different treatment approaches. Chemotherapy targets rapidly dividing cells, while immunotherapy works by influencing the body’s immune response to cancer. In the ATOMIC study, this combination produced better disease-free survival outcomes than chemotherapy alone among patients with stage III dMMR colon cancer.
The approval therefore highlights the importance of molecular testing in identifying patients who may benefit from a treatment tailored to their tumor’s biological characteristics.
Colon Cancer Continues to Present a Significant Global Health Challenge
Colon cancer remains one of the most commonly diagnosed cancers worldwide and a major cause of cancer-related mortality. More than one million people are diagnosed with the disease globally each year, and nearly one-quarter of colon cancer cases are diagnosed at stage III.
At this stage, the cancer has generally spread beyond the innermost layers of the colon wall to nearby lymph nodes, although it has not spread to distant organs in the manner characteristic of stage IV disease.
Treatment commonly involves surgery to remove the tumor, followed by chemotherapy to address microscopic cancer cells that may remain after the operation. Even with these interventions, recurrence remains a substantial concern.
Genentech’s announcement notes that nearly 30% of patients with stage III colon cancer experience disease recurrence within five years despite surgery and chemotherapy.
The risk of recurrence underscores the need for treatments that can improve long-term disease control. For patients with dMMR tumors, the ATOMIC trial suggests that adding immunotherapy to chemotherapy may offer a clinically meaningful improvement over chemotherapy alone.
The new approval is particularly relevant because it establishes an immunotherapy-based adjuvant regimen for a patient population defined by a specific molecular abnormality. Rather than treating all stage III colon cancers as biologically identical, the approach recognizes the potential importance of mismatch repair status when selecting postoperative treatment.
Improved access to molecular testing and the integration of biomarker information into clinical practice will remain important considerations as treatment strategies evolve.
Clinical Significance and Potential Impact on Treatment Standards
Frank A. Sinicrope, M.D., professor of oncology at the Mayo Clinic and U.S. principal investigator for the Alliance ATOMIC trial, described the approval as an important therapeutic advance.
“Until now, the adjuvant standard of care for stage III colon cancer has not differed based on mismatch repair status,” Sinicrope said.
He explained that the milestone uses immunotherapy to target the specific biology of stage III dMMR colon cancer after surgical resection. He also characterized the 50% reduction in the risk of recurrence or death as a practice-changing result with the potential to improve clinical outcomes for this patient population.
The findings could influence how clinicians approach postoperative treatment for patients with stage III dMMR colon cancer. The combination of Tecentriq and chemotherapy provides a new option supported by Phase III evidence and an FDA regulatory decision.
However, the practical impact of the approval will depend on factors including the identification of eligible patients, interpretation of tumor testing, treatment tolerability, clinical guidelines and access to the medicines.
The results also contribute to the broader development of precision oncology, in which therapies are selected according to the molecular and biological features of an individual patient’s cancer.
For healthcare providers, determining mismatch repair status can help establish whether patients fall within the population for which the new regimen has demonstrated benefit. For patients, the availability of an additional treatment option may provide an opportunity to improve the likelihood of remaining disease-free following surgery.
Tecentriq’s Expanding Role in Cancer Treatment
The approval marks the twelfth U.S. indication for Tecentriq, extending the medicine’s role in cancer treatment. Its inclusion in an adjuvant regimen for stage III dMMR colon cancer adds another application for PD-L1-targeted immunotherapy.
Tecentriq and Tecentriq Hybreza are two formulations included in the FDA approval announcement. Tecentriq contains atezolizumab, while Tecentriq Hybreza combines atezolizumab with hyaluronidase-tqjs. Both are approved for use in combination with a fluoropyrimidine and oxaliplatin for the specified adjuvant treatment setting.
The decision reinforces the importance of clinical research in establishing new uses for existing cancer medicines. The ATOMIC study provides evidence that immunotherapy can improve disease-free survival when incorporated into postoperative chemotherapy for a defined subgroup of colon cancer patients.
The findings also illustrate how advances in biomarker testing and immune-based treatment can work together to address areas of unmet medical need.
As clinicians integrate the new option into treatment discussions, the principal consideration will be identifying patients with stage III dMMR colon cancer who may benefit from the combination and evaluating the potential benefits and risks for each individual.
The FDA approval of Tecentriq and Tecentriq Hybreza in combination with a fluoropyrimidine and oxaliplatin represents a significant development in the adjuvant treatment of stage III dMMR colon cancer.
Supported by the Phase III ATOMIC trial, the approval is based on evidence showing a 50% reduction in the risk of disease recurrence or death and 36-month disease-free survival of 86% with Tecentriq plus mFOLFOX6, compared with 76% with chemotherapy alone.
For patients facing a high risk of recurrence after surgery, the regimen introduces an immunotherapy-based option that targets the biological characteristics of dMMR tumors. The decision also underscores the growing role of molecular testing and precision medicine in guiding cancer care.
With colon cancer continuing to affect more than one million people worldwide annually, improvements in postoperative treatment remain an important clinical priority. The ATOMIC findings and subsequent FDA approval provide new evidence supporting the integration of immunotherapy into treatment for eligible patients with stage III dMMR colon cancer.
About the ATOMIC study
ATOMIC (A021502, NCT02912559) is a Phase III, randomized, open-label, multicenter study investigating the addition of Tecentriq® (atezolizumab) to mFOLFOX6 chemotherapy (a combination of folinic acid, fluorouracil, and oxaliplatin) in patients with stage III colon cancer who have a deficiency in DNA mismatch repair (dMMR). The trial enrolled 712 patients. Participants were randomized 1:1 to receive either mFOLFOX6 plus Tecentriq for 12 cycles (six months) followed by Tecentriq monotherapy for 13 cycles (an additional six months), or mFOLFOX6 alone for 12 cycles. The primary endpoint is disease-free survival (DFS).
The global study in the U.S. was sponsored by the U.S. National Cancer Institute (NCI), part of the National Institutes of Health, and led by the Alliance for Clinical Trials in Oncology (Alliance) with participation from other NCI-funded National Clinical Trials Network (NCTN) groups. Genentech provided support for the study through a Cooperative Research and Development Agreement between NCI and Genentech. The trial was led globally by Frank A. Sinicrope, M.D., professor of oncology at the Mayo Clinic and U.S. principal investigator within the Alliance.
German participation in this major international academic collaboration was enabled through close cooperation between the Alliance and the AIO-Studien-gGmbH, in partnership with the AIO (Arbeitsgemeinschaft Internistische Onkologie) of the German Cancer Society (Deutsche Krebsgesellschaft, DKG), under the national leadership of Prof. Dr. Anke Reinacher-Schick (Ruhr-Universität Bochum). AIO-affiliated study sites enrolled patients during the later recruitment phase, ensuring access for eligible patients in Germany.
About Tecentriq® (atezolizumab)
Tecentriq is a monoclonal antibody designed to bind with a protein called PD-L1, which is expressed on tumor cells and tumor-infiltrating immune cells, blocking its interactions with both PD-1 and B7.1 receptors. By inhibiting PD-L1, Tecentriq may enable the re-activation of T cells. Tecentriq may also affect normal cells.
Tecentriq has been approved for some of the most aggressive and difficult-to-treat forms of cancer, and is the first PD-(L)1 cancer immunotherapy available in both subcutaneous and intravenous formulations.