
Roche’s cancer immunotherapy Tecentriq (atezolizumab), a PD-L1 inhibitor, scored its fifth Food and Drug Administration approval on Friday, for advanced triple-negative breast cancer, but the fifth was a first: Before this decision, no immunotherapies had been approved for any form of breast cancer.
The approval, as is typical, was narrow: for locally advanced or metastatic triple-negative breast cancer expressing PD-L1, the molecule that locks onto PD-1 receptors on the surface of T cells. (Triple-negative means the tumor cells do not have estrogen receptors, progesterone receptors, or HER2, all of which fuel uncontrolled cell proliferation but can be blocked with drugs such as Herceptin.)