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.
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.
- Rimm DL, Han G, Taube JM, et al. A prospective, multi-institutional, pathologist-based assessment of 4 immunohistochemistry assays for PD-L1 expression in non–small cell lung cancer. JAMA Oncol. doi: 10.1001/jamaoncol.2017.0013 [Epub ahead of print]