The US Food & Drug Administration's (FDA) decision to approve a medication to treat patients whose cancer has a specific genetic feature, or biomarker, has been hailed as an "important first" in the fight against the disease. Keytruda (pembrolizumab) is a monoclonal antibody already in use to treat patients with melanoma, head and neck cancer, Hodgkin lymphoma and non-small cell lung cancer. 

However, the latest accelerated approval granted to Merck & Co by the FDA enables healthcare providers to prescribe the drug to patients whose tumors have a biomarker referred to as microsatellite instability-high (MSI-H) or mismatch repair deficient (dMMR). These tumors contain abnormalities hampering normal repair of DNA in the cells. The biomarker is most commonly found in patients with colorectal, endometrial and garstrointestinal cancer, but those with breast, prostate, thyroid gland and bladder cancers may also benefit from the new treatment.

Earlier this month, Merck & Co was granted approval for Keytruda as a first line treatment alongside chemotherapy for patients with lung cancer. Chemotherapy is used to treat an extensive variety of cancers and involves drugs such as Rheumatrex (methotrexate). Every year, more than 1.5 million people in the U.S. are diagnosed with cancer, with breast cancer, lung cancer and prostate cancer the most common.  

Richard Pazdur, MD, acting director of the Office of Hematology and Oncology Products in the FDA's Center for Drug Evaluation and Research and director of the FDA's Oncology Center of Excellence, commented: "This is an important first for the cancer community. Until now, the FDA has approved cancer treatments based on where in the body the cancer started… We have now approved a drug based on a tumor's biomarker without regard to the tumor's original location."

The FDA granted accelerated approval with priority review designation. This is given to drugs that may significantly improve the safety or effectiveness of treating, diagnosing or preventing a serious condition. The trial testing the efficacy of Keytruda looked at data from 149 patients given the prescription drug. Almost four in ten demonstrated a complete or partial response to the medication, with nearly eight in ten experiencing a response lasting at least six months. 

For more information on Keytruda, visit the link below: 

 https://www.keytruda.com/