The US Food and Drug Associatin has approved the breakthrough lung cancer drug Keytruda (pembrolizumab) that was tested on 500 patients to treat advanced non-small cell lung cancer.
When results were overwhelmed in the test, FDA gave the drug “breakthrough therapy” status in October 2014 and a year later gave it approval, showcasing one of the fast-tracked approval by the US agency. Keytruda enables the patient’s immune system to attack the cancer.
“The approval of this drug and a test to identify patients most likely to benefit has the potential to transform the way that lung cancer is treated,” said Dr. Edward Garon, a researcher at University of California, Los Angeles’ Jonsson Comprehensive Cancer Center.
“The quality and duration of disease response that was seen in the trial had previously been extremely rare in lung cancer. For people battling this deadly disease, this approach provides real hope of long-lasting responses while avoiding the toxicities of typical chemotherapy,” he said.
The response rate and duration of response for Keytruda were much greater than for drugs traditionally used to treat lung cancer and in its 3-year clinical trial, the response rate was 19%. The average duration of response exceeded one year, a remarkable advance in a highly difficult disease.
Keytruda is already proved to have extended the lives of people with advanced melanoma, with its antibody that targets the protein PD-1, which is expressed by immune cells. When it binds to another protein called PD-L1, PD-1 acts as an immune checkpoint, dampening the immune system’s T cells which otherwise could attack cancer cells.
Lung cancer is the leading cause of cancer death in the United States, with an estimated 221,200 new diagnoses and 158,040 deaths in 2015, according to the National Cancer Institute.
NSCLC is the most common type of lung cancer.“Our growing understanding of underlying molecular pathways and how our immune system interacts with cancer is leading to important advances in medicine,” said Richard Pazdur, director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research.
Keytruda is marketed by Merck based in Whitehouse Station, New Jersey and the PD-L1 IHC 22C3 pharmDx diagnostic test is marketed by Dako North America.