In cancer immunotherapy, one PD-L1 test to rule them all?
Clinical trials have proven the power of immunotherapies targeting PD-L1 or PD-1 in a range of cancers. However, these same trials show that only some patients benefit - tumors must depend on PD-L1 to be affected when medicines block its action. In response, the companies Merck, AstraZeneca, Genentech/Roche, and Bristol-Myers Squibb together with the diagnostic companies Ventana and Dako have developed four tests to predict which tumors do and do not express on PD-L1 and thus which tumors will respond to the therapies....