PD-L1 immunohistochemical expression in bladder urothelial cancer with SP263, SP142 and 22C3 antibodies: A comparative study.

Programmed death ligand 1 (PD-L1) is currently the only biomarker used for the selection of patients with bladder urothelial cancer for immunotherapy. Several platforms, antibodies and scores are currently available for the evaluation of the expression of PD-L1 in immunohistochemistry (IHC). In this study three different antibodies (SP263, SP142 and 22C3) were compared to establish their performances and concordance rates. Twenty-four consecutive cases of surgically resected urothelial cancers of the bladder were enrolled. All cases were revised, and appropriate tumor areas were selected for IHC. Three commercially available PD-L1 antibodies were tested: 22C3 pharmDx with Dako Autostainer Link 48 (Dako, Carpinteria, Ca), and SP263 and SP142 with the Ventana BenchMark (Ventana Medical Systems, Tucson, AZ) platform. All slides were evaluated by an expert pathologist and both the tumor proportion score (TPS) and the combined positive score (CPS) were determined and compared at two different cut-off levels (≥ 1 and ≥ 10). The SP263 and 22C3 clones produced more positive results with the CPS and TPS scores, respectively. The CPS score identified more positive cases than the TPS score, irrespectively of the clone or the cut-off used; the difference was statistically significant in both the SP263 and SP142 clones with the ≥1 cut-off. No statistically significant differences were found between the clones when the ≥1 cut-off was used, irrespectively of the score. At the contrary, a statistically significant difference (p = 0.024) and a trend to significance (p = 0.082) were respectively found for the TPS and CPS scores, when the SP22C3 and the SP142 clones were compared at a cut-off level of ≥10. The ICC test using CPS was 0.676 and 0.578 for the ≥1 and ≥ 10 cut-offs respectively, and 0.729 and 0.467 respectively for the same cut-offs using TPS. This suggests that the three antibodies under investigation cannot be used interchangeably, especially the 22C3 and SP142 clones which showed statistically significant difference when TPS was tested at a ≥ 10 cut-off.

Paliogiannis P ，Lobrano R ，Bella MA ，Fara A ，Uras MG ，Pinna MA ，Tedde A ，Madonia M ，Zinellu A ，Cossu A ... -  《-》

Programmed death ligand-1 (PD-L1) immunohistochemical assessment using the QR1 clone in muscle-invasive urothelial carcinomas: a comparison with reference clones 22C3 and SP263.

Loghin A ，Nechifor-Boilă A ，Borda A ，Nechifor-Boilă IA ，Voidazan S ，Decaussin-Petrucci M ... -  《-》

Comparison of three validated PD-L1 immunohistochemical assays in urothelial carcinoma of the bladder: interchangeability and issues related to patient selection.

Different programmed cell death-ligand 1 (PD-L1) assays and scoring algorithms are being used in the evaluation of PD-L1 expression for the selection of patients for immunotherapy in specific settings of advanced urothelial carcinoma (UC). In this paper, we sought to investigate three approved assays (Ventana SP142 and SP263, and Dako 22C3) in UC with emphasis on implications for patient selection for atezolizumab/pembrolizumab as the first line of treatment. Tumors from 124 patients with invasive UC of the bladder were analyzed using tissue microarrays (TMA). Serial sections were stained with SP263 and SP142 on Ventana Benchmark Ultra and with 22C3 on Dako Autostainer Link 48. Stains were evaluated independently by two observers and scored using the combined positive score (CPS) and tumor infiltrating immune cells (IC) algorithms. Differences in proportions (DP), overall percent agreement (OPA), positive percent agreement (PPA), negative percent agreement (NPA), and Cohen κ were calculated for all comparable cases. Good overall concordance in analytic performance was observed for 22C3 and SP263 with both scoring algorithms; specifically, the highest OPA was observed between 22C3 and SP263 (89.6%) when using CPS. On the other hand, SP142 consistently showed lower positivity rates with high differences in proportions (DP) compared with 22C3 and SP263 with both CPS and IC, and with a low PPA, especially when using the CPS algorithm. In conclusion, 22C3 and SP263 assays show comparable analytical performance while SP142 shows divergent staining results, with important implications for the selection of patients for both pembrolizumab and atezolizumab.

Munari E ，Querzoli G ，Brunelli M ，Marconi M ，Sommaggio M ，Cocchi MA ，Martignoni G ，Netto GJ ，Caliò A ，Quatrini L ，Mariotti FR ，Luchini C ，Girolami I ，Eccher A ，Segala D ，Ciompi F ，Zamboni G ，Moretta L ，Bogina G ... -  《Frontiers in Immunology》

Multicenter Comparison of 22C3 PharmDx (Agilent) and SP263 (Ventana) Assays to Test PD-L1 Expression for NSCLC Patients to Be Treated with Immune Checkpoint Inhibitors.

Among the several agents targeting the programmed cell death 1 (PD-1) pathway, pembrolizumab is currently the only one approved for the treatment of patients with NSCLC in association with a companion diagnostic assay, the anti-PD-L1 immunohistochemical (IHC) 22C3 PharmDx (Agilent Technologies, Santa Clara, CA) using the Dako Autostainer (Dako, Carpinteria, CA). However, the Dako platform is not present in each pathology department, and this technical limitation is a major problem for the diffusion of the PD-L1 IHC predictive test for pembrolizumab. The Italian Society of Anatomic Pathology and Cytopathology and the Italian Association of Medical Oncology in an independent, multicenter study compared the in vitro diagnostics PD-L1 IHC 22C3 pharmDx test (Agilent) on the Dako Autostainer and the in vitro diagnostics Ventana PD-L1 (SP263) test on the Ventana BenchMark platform (Ventana Medical Systems, Tucson, AZ). Using serial sections from tissue microarrays, 100 lung adenocarcinomas were locally stained and scored in four centers with the same antibody batches. A high analytical correlation (more than 90% at the lower 95% confidence interval [CI] value) between PD-L1 expression levels obtained with the 22C3 and SP263 assays was observed. At the proposed clinically relevant cutoffs (≥50% and ≥1%), the overall concordances between 22C3 and SP263 data were 0.99 (95% CI: 0.96-1) and 0.80 (95% CI: 0.68-0.91), respectively. The lower agreement between data obtained with the 22C3 and SP263 clones at the cutoff of 1% or higher was mainly related to the lower (about 80%) interrater agreement at this cutoff with each clone. These results indicate a high correlation between PD-L1 IHC expression data obtained with the Agilent PD-L1 IHC 22C3 pharmDx and the Ventana PD-L1 (SP263) tests in NSCLC and suggest that the two assays could be utilized interchangeably as an aid to select patients for first-line and second-line treatment with pembrolizumab and potentially with other anti-PD-1/PD-L1 checkpoint inhibitors.

Marchetti A ，Barberis M ，Franco R ，De Luca G ，Pace MV ，Staibano S ，Volante M ，Buttitta F ，Guerini-Rocco E ，Righi L ，D'antuono T ，Scagliotti GV ，Pinto C ，De Rosa G ，Papotti M ... -  《-》

Concordance among four commercially available, validated programmed cell death ligand-1 assays in urothelial carcinoma.

Zajac M ，Scott M ，Ratcliffe M ，Scorer P ，Barker C ，Al-Masri H ，Rebelatto MC ，Walker J ... -  《Diagnostic Pathology》