“FDA approves 1st drug for biomarker-based therapy”
In an unprecedented move, the FDA today granted accelerated approval to the cancer drug pembrolizumab (Keytruda – Merck & Co) for treatment of any unresectable or metastatic solid tumors associated with the genetic abnormality known as microsatellite instability.
It’s the first time the agency approved a cancer treatment or indication that is not for a tumor arising from a specific tissue type, but rather is based on presence of a particular biomarker regardless of tumor origin.
“This is an important first for the cancer community,” Richard Pazdur, MD, of the FDA Office of Hematology and Oncology Products, said in a statement. “Until now, the FDA has approved cancer treatments based on where in the body the cancer started — for example, lung or breast cancers. We have now approved a drug based on a tumor’s biomarker without regard to the tumor’s original location.”
Microsatellite instability-high (MSI-H) or mismatch repair deficiency (dMMR) are types of genetic abnormalities that affect cells’ internal mechanisms to repair DNA damage. Cancer exploits the defects to perpetuate the development of abnormal cells. MSI-H and dMMR occur most often in colorectal, endometrial, and gastrointestinal cancers (including about 5% of patients with metastatic colorectal cancer, particularly those with familial syndromes).