A new companion diagnostic test for colorectal cancer, the MMR IHC Panel pharmDx (Dako Omnis), has received FDA approval for Agilent Technologies.

The MMR pathway is a crucial biological process that corrects errors in DNA replication to maintain genomic stability. When key proteins in this pathway—MLH1, PMS2, MSH2, and MSH6—malfunction, it leads to a state of mismatch repair deficiency (dMMR). This deficiency causes an increase in genetic mutations and the accumulation of neoantigens, which makes the tumors more recognizable and vulnerable to the patient's immune system. As a result, dMMR tumors often respond well to immunotherapy.

The new Agilent test, which is an immunohistochemical (IHC) panel, detects the loss of function of any of these four key MMR proteins in colorectal cancer tissue. It is the only FDA-approved companion diagnostic IHC panel for this specific purpose, providing healthcare providers with a reliable tool to inform treatment decisions.

According to Nina Green, vice-president and general manager of Agilent’s Clinical Diagnostics Division, this new diagnostic panel is a crucial step forward in colorectal cancer care. It provides clinicians with an additional tool to accurately identify patients who could benefit from immunotherapy, complementing existing diagnostic options. By improving the ability to select the right patients for these targeted treatments, the test aims to enhance tumor control and potentially improve patient outcomes, including progression-free survival. This partnership between Agilent and Bristol Myers Squibb underscores a shared commitment to advancing precision medicine and improving the well-being of patients facing colorectal cancer.