FDA Approves Dako Omnis Test to Guide Colorectal Cancer Treatment

The FDA approved the Dako Omnis panel to identify patients with colorectal cancer with mismatch repair deficiency.

The mismatch repair immunohistochemical panel pharmDx (Dako Omnis) has received U.S. Food and Drug Administration (FDA) approval as a companion diagnostic test for colorectal cancer, according to a news release from Agilent Technologies.

The Dako Omnis test helps identify patients with mismatch repair deficient colorectal cancer who may be eligible for treatment with Opdivo alone or with Opdivo (nivolumab) plus Yervoy (ipilimumab).

“This approval marks an important step forward in the ongoing effort to improve colorectal cancer care,” Nina Green, vice-president and general manager of Agilent’s Clinical Diagnostics Division, said in the news release. “Our new companion diagnostic product offers healthcare providers an additional tool to identify mismatch repair deficiency in patients, complementing existing options and enhancing the ability to tailor immunotherapy treatments. By providing more choices, we aim to support better tumor control and potentially improve progression-free survival, ultimately contributing to patient care and well-being.”

The mismatch repair pathway fixes mistakes that happen when cells copy their DNA. When this system does not work properly, changes build up in the DNA, which can lead to cancer. These cancers often have features that make them easier for the immune system to recognize, which is why some respond well to immunotherapy.

The test was developed and validated to detect loss of function in any of the four mismatch repair proteins in preserved colorectal cancer tissue. It is the only FDA-approved companion diagnostic immunohistochemistry panel to identify patients with colorectal cancer who may be treated with Opdivo alone or with Yervoy.

More information on Daki Omnis

Dako Omnis is an immunohistochemistry test designed and validated to detect loss of function in any of the four mismatch repair proteins in preserved colorectal cancer tissue. It is the only FDA-approved companion diagnostic panel to identify patients with colorectal cancer who may receive Opdivo alone or with Yervoy.

Deficiencies in mismatch repair can lead to hypermutability and a condition called microsatellite instability, according to the National Library of Medicine. Detecting mismatch repair deficiency or microsatellite instability has diagnostic, predictive and prognostic value. It is used for Lynch syndrome screening, to help determine which patients may respond to immune checkpoint inhibitors, and to identify those who may experience a more aggressive disease course. Microsatellite instability can be assessed directly with polymerase chain reaction (PCR) or next-generation sequencing, or indirectly through immunohistochemistry to evaluate mismatch repair protein expression.

About 5% to 15% of colorectal cancers have mismatch repair deficiency or microsatellite instability-high status, which is linked to high tumor mutation burden and increased immunogenicity. Many of these cancers respond well to immunotherapy, though some remain resistant. Current research focuses on understanding resistance mechanisms, identifying predictive biomarkers and developing strategies to guide treatment. Advances in diagnosis, molecular characterization and the use of predictive factors are also shaping treatment approaches for localized and metastatic disease in both the neoadjuvant and adjuvant settings.

Previous FDA Approval for Colorectal Cancer

The FDA has also approved an investigational new drug application for ABT-301, enabling a phase 1/2 clinical trial of the drug in combination with Tevimbra (tislelizumab) and Avastin (bevacizumab) for patients with metastatic colorectal cancer, according to CURE.

According to Anbogen Therapeutics, the clinical-stage biotechnology company developing ABT-301, the open-label, multi-center international study will enroll about 66 patients with proficient mismatch repair or non-microsatellite instability-high metastatic colorectal cancer, with enrollment planned in Taiwan and Australia.

References

1. Agilent MMR IHC Panel pharmDx (Dako Omnis) Receives FDA Approval as a Companion Diagnostic Test for Colorectal Cancer.” Agilent Technologies. News Release. August 20, 2025.
2. Mismatch repair deficiency: The what, how and why it is important,” by Olave MC, et al. Genes Chromosomes Cancer.
3. “Challenges and Therapeutic Opportunities in the dMMR/MSI-H Colorectal Cancer Landscape,” by Nuria Mulet-Margalef et al. Cancers.

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