Development of a Diagnostic Programmed Cell Death 1-Ligand 1 Immunohistochemistry Assay for Nivolumab Therapy in Melanoma

Abstract

Nivolumab is a monoclonal antibody that blocks the interaction between programmed cell death 1 (PD1) and programmed cell death 1-ligand 1 (PD-L1), resulting in enhanced antitumor activity by the immune system. Nivolumab is currently approved by the US Food and Drug Administration (FDA) for melanoma, non-small cell lung cancer (NSCLC), renal cell carcinoma, classical Hodgkin lymphoma, squamous cell carcinoma of the head and neck, and urothelial carcinoma. PD-L1 IHC 28-8 pharmDx is FDA-approved as a complementary diagnostic for immunohistochemical (IHC) detection of PD-L1 in non-squamous NSCLC and melanoma. We report validation of PD-L1 IHC 28-8 pharmDx for PD-L1 detection on formalin-fixed, paraffin-embedded human melanoma specimens using Autostainer Link 48. A prevalence assessment of 104 melanoma specimens indicated that PD-L1 was detected across the full expression level range (0% to 100% of tumor cells). Assay robustness and precision studies were conducted at Agilent Technologies, with additional reproducibility studies performed at 3 external laboratories. Precision studies evaluated at ≥1% and ≥5% expression levels revealed a range of average negative agreement from 89.5%, 95% CI (83.2, 93.6) to 100%, 95% CI (97.3, 100), and average positive agreement from 85.5%, 95% CI (77.6, 90.9) to 100%, 95% CI (97.9, 100). For external reproducibility, precise results were obtained. These results demonstrate PD-L1 IHC 28-8 pharmDx is a precise, robust, and reproducible assay for determining PD-L1 expression in melanoma. This is the first PD-L1 IHC test to receive FDA approval as a complementary diagnostic in melanoma patients whereby positive PD-L1 expression is correlated with the magnitude of nivolumab treatment effect.

Comparison of three scoring methods using the FDA-approved 22C3 immunohistochemistry assay to evaluate PD-L1 expression in breast cancer and their association with clinicopathologic factors

“…Over the past decade, monoclonal antibody-based immune checkpoint inhibitors targeting programmed death-1 (PD-1) and its ligand, programmed death-ligand 1 (PD-L1), have been developed and approved by the U.S. Food and Drug Administration (FDA) for the treatment of solid tumors such as non-small cell lung cancer, melanoma, urothelial carcinoma, and head and neck squamous cell carcinoma [1][2][3][4][5]. The FDA has also approved several diagnostic immunohistochemistry (IHC) assays corresponding to these drugs to detect PD-L1 expression and inform the selection of patients for treatment [6][7][8][9][10][11]. However, when these different immune checkpoint inhibitors are used for the same tumor type, the corresponding IHC assays may be scored differently.…”

PD-L1 expression is an unfavourable prognostic indicator in Asian renal cell carcinomas

“…Although the Checkmate 025 trial failed to show any additional benefit for the PD-L1-positive expression subgroup of nivolumab single agent,19 44 the newly reported Checkmate 214 trial, which used nivolumab in combination with ipilimumab (anti-CTLA4, another immune checkpoint molecule) demonstrated more benefit to PD-L1-positive patients compared with PD-L1-negative patients 14. However, these studies used the PD-L1 clone 28–8, which requires a specific kit, setup and autostainer to perform the labelling successfully, and these may not be accessible to the majority of research and diagnostic laboratories 45–48. The different antibodies, labelling methods, evaluation methods and geographical regions investigated across studies have posed a challenge in the field 49–52.…”

Fit-For-Purpose PD-L1 Biomarker Testing For Patient Selection in Immuno-Oncology: Guidelines For Clinical Laboratories From the Canadian Association of Pathologists-Association Canadienne Des Pathologistes (CAP-ACP)

“…There are multiple different commercially available PD-L1 IHC companion/complementary diagnostic assays (PD-L1 IHC Kits). These PD-L1 assays were developed and clinically validated by clinical trials [35][36][37][38][39][40][41] for different drug-disease combinations, using different PD-L1 primary antibody (Ab) clones on different IHC platforms with different IHC protocols and requiring different readout criteria for what is considered to be "positive" in different disease contexts. PD-L1 IHC Kits are reasonably considered reference standard assays for their respective drugdisease indications based on the Clinical and Laboratory Standards Institute (CLSI) guidelines for determining the diagnostic accuracy of qualitative assays.…”