Key Concepts:
- While the current diagnostic strategies for PD-L1 checkpoint inhibitors identify some responders well, the majority of patients still need diagnostic approaches that better predict response.
- PD-L1 IHC remains a valuable tool for predicting patient response, but can be limited by the ability to correctly use the test to interpret the complex underlying biology and response profile.
- New IHC interpretation methods are capturing this biology and defining better patient selection tests, but the interpretations are complicated and hard for pathologists to implement.