Evaluating Concordance Among PD-L1 Assays in Non-small Cell Lung Cancer

Among 4 PD-L1 platforms evaluated for performance, the SP142 antibody on the Ventana Benchmark platform was the least effective for detecting PD-L1 expression in tumor cells, according to an article published in JAMA Oncology.¹

Four assays are used to test for PD-L1 expression in tissue samples, the results of which can determine therapy choices for particular patients. Three drug-specific PD-L1 tests are approved by the U.S. Food and Drug Administration (FDA) to help guide therapy among PD-1 and PD-L1 inhibitors, each of which uses a different antibody and assay condition.

To compare the effectiveness and accuracy of the 3 drug-specific assays and 1 additional assay (Dako/Agilent 28-8, Dako/Agilent 22c3, Ventana SP142, and Leica Bond E1L3N), the authors asked 13 pathologists to evaluate 90 non-small cell lung cancer samples for PD-L1 expression.

All tests excluding Ventana SP142 performed about equally; Ventana SP142, however, correctly detected PD-L1 expression in only about half of the evaluated samples. The 13 pathologists had similar evaluations of tumor cell samples but disparity in evaluations of immune cell samples.  

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The authors concluded that Dako/Agilent 28-8, Dako/Agilent 22c3, and Leica Bond E1L3N yield similar results for PD-L1 expression testing in tumor cells, though Ventana SP142 is a less effective assay.