3-D structure of a melanoma cell WIKIMEDIA, SRIRAM SUBRAMANIAM, NCIWith the US Food and Drug Administration’s final green light last week (September 4), Merck’s pembrolizumab, which the pharmaceutical giant plans to market as Keytruda, is the first US-approved drug that blocks the immune brake known as programmed death receptor 1 (PD-1), unleashing certain immune cells to wreak havoc on a patient’s tumor. The approval—which “followed a swift review of data from a relatively early-stage human trial,” The Wall Street Journal (WSJ) reported—will allow doctors to prescribed the drug in cases of melanoma, though some researchers emphasize the promise of pembrolizumab and similar drugs for other types of cancer, as well.
“PD-1 is truly a game-changer. It’s active in a way that other drugs are not,” Lynn Schuchter, a medical oncologist who heads the melanoma program at the Abramson Cancer Center of the University of Pennsylvania and has assisted in clinical trials of the Merck drug, told WSJ. “And what’s been interesting is the activity of PD-1 beyond melanoma. It looks to be active in bladder and renal and lung cancer. So this is bigger than melanoma.”
In a clinical trial this summer, more than two-thirds of advanced melanoma patients who received pembrolizumab survived at least one year post-treatment; 62 percent were alive after 18 months, the researchers reported. The trial also revealed notable tumor shrinkage in about one-third of patients. Merck now must run two ...
