The drug is a ‘game changer,’ says UCLA’s Dr. Antoni Ribas, the study’s principal investigator.
The U.S. Food and Drug Administration today (Sept.4) approved a new immunotherapy drug to treat advanced melanoma, signaling a paradigm shift in the way the deadly skin cancer is treated.
The drug, Keytruda, was tested on more than 600 patients who had melanoma that had spread throughout their bodies. Because so many of the patients in the early testing showed significant long-lasting responses, the study was continued and the FDA granted the drug “breakthrough therapy” status, allowing it to be fast-tracked for approval.
The largest phase one study in the history of oncology, the research was conducted at UCLA and 11 other sites in the U.S., Europe and Australia.
Keytruda, formerly known as MK-3475, is an antibody that targets a protein called PD-1 that is expressed by immune cells. The protein puts the immune system’s brakes on, keeping its T cells from recognizing and attacking cancer cells, said Dr. Antoni Ribas, the study’s principal investigator and a professor of medicine in the division of hematology–oncology at the David Geffen School of Medicine at UCLA.
For many years, when using immunotherapy to fight cancer, doctors’ strategy has been to bolster the immune system so it could kill the cancer cells. But the approach had limited success because PD-1 prevented the immune system from becoming active enough to attack the cancer. Keytruda, in effect, cuts the brake lines, freeing up the immune system to attack the cancer.
“This drug is a game changer, a very significant advance in the treatment of melanoma,” said Ribas, who also is a researcher at UCLA’s Jonsson Comprehensive Cancer Center. “For patients who have not responded to prior therapies, this drug now provides a very real chance to shrink their tumors and the hope of a lasting response to treatment.”