Former President Jimmy Carter credits the new cancer drug Keytruda for shrinking his brain tumors completely. It's one more victory for the newest class of cancer drugs that empower the immune system to fight off tumors, NBC News reported.
While most immune therapy drugs boost the immune system so that it can battle the cancer, Keytruda was the first drug to take a different approach that disrupts a trick tumors use to hide from immune cells.
Keytruda — known generically as pembrolizumab — targets the activity of genes called PD-1 and PD-L1. The interaction between the two genes lets some tumors escape detection and destruction by immune system cells.
The Food and Drug Administration gave Keytruda accelerated approval in 2014 for patients, like Carter, whose melanoma has spread. It was on the basis of a big study that showed Keytruda could shrink the tumors of about a third of patients by as much as 90 percent.