Concordance among four commercially available, validated programmed cell death ligand-1 assays in urothelial carcinoma.
ABSTRACT: BACKGROUND:Antibodies targeting the programmed cell death-1 (PD-1)/PD-ligand 1 (PD-1/PD-L1) checkpoint have shown promising clinical activity in patients with advanced urothelial carcinoma (UC). Expression of PD-L1 in UC tumors has been investigated using different antibody clones, staining protocols, and scoring algorithms. The aim was to establish the extent of concordance among PD-L1 immunohistochemistry (IHC) assays. METHODS:Tumor biopsy samples (N = 335) were assessed using four commercially available PD-L1 assays: VENTANA SP263, VENTANA SP142, PD-L1 IHC 28-8 pharmDx, and PD-L1 IHC 22C3 pharmDx. PD-L1 analytical staining and classification concordance, including agreement between clinically relevant scoring algorithms, were investigated using overall/positive/negative percentage agreement (OPA/PPA/NPA). RESULTS:Good analytical correlation was observed among the VENTANA SP263, PD-L1 IHC 22C3 pharmDx, and PD-L1 IHC 28-8 pharmDx assays for tumor cell (TC) and immune cell (IC) PD-L1 staining with Spearman rank coefficients of 0.92-0.93 for TCs and 0.88-0.91 for ICs. However, concordance (preset criterion: ≥85%) between patient PD-L1 status when applying the TC or ICICArea ≥ 25% (VENTANA SP263) cutoff was only achieved for PD-L1 IHC 22C3 pharmDx versus VENTANA SP263 (OPA 92.2%, PPA 86.4%, NPA 95.4%). Differences were observed between patient populations with UC tumors classified as PD-L1 high versus PD-L1 low/negative using combined positive score (CPS) ≥1, CPS ≥10, IC ≥5%, and TC/IC ≥25%. CONCLUSIONS:The VENTANA SP263 and PD-L1 IHC 22C3 pharmDx assays are analytically similar in UC. When the different PD-L1 assays were combined with their specified clinical scoring algorithms, differences were seen in patient classification driven by substantial differences in scoring approaches.
Project description:For non-small cell lung cancer (NSCLC), treatment with pembrolizumab is limited to patients with tumours expressing PD-L1 assessed by immunohistochemistry (IHC) using the PD-L1 IHC 22C3 pharmDx (Dako, Inc.) companion diagnostic test, on the Dako Autostainer Link 48 (ASL48) platform. Optimised protocols are urgently needed for use of the 22C3 antibody concentrate to test PD-L1 expression on more widely available IHC autostainers.We evaluated PD-L1 expression using the 22C3 antibody concentrate in the three main commercially available autostainers Dako ASL48, BenchMark ULTRA (Ventana Medical Systems, Inc.), and Bond-III (Leica Biosystems) and compared the staining results with the PD-L1 IHC 22C3 pharmDx kit on the Dako ASL48 platform. Several technical conditions for laboratory-developed tests (LDTs) were evaluated in tonsil specimens and a training set of three NSCLC samples. Optimised protocols were then validated in 120 NSCLC specimens.Optimised protocols were obtained on both the VENTANA BenchMark ULTRA and Dako ASL48 platforms. Significant expression of PD-L1 was obtained on tissue controls with the Leica Bond-III autostainer when high concentrations of the 22C3 antibody were used. It therefore was not tested on the 120 NSCLC specimens. An almost 100% concordance rate for dichotomized tumour proportion score (TPS) results was observed between TPS ratings using the 22C3 antibody concentrate on the Dako ASL48 and VENTANA BenchMark ULTRA platforms relative to the PD-L1 IHC 22C3 pharmDx kit on the Dako ASL48 platform. Interpathologist agreement was high on both LDTs and the PD-L1 IHC 22C3 pharmDx kit on the Dako ASL48 platform.Availability of standardized protocols for determining PD-L1 expression using the 22C3 antibody concentrate on the widely available Dako ASL48 and VENTANA BenchMark ULTRA IHC platforms will expand the number of laboratories able to determine eligibility of patients with NSCLC for treatment with pembrolizumab in a reliable and concordant manner.
Project description:Tumor programmed cell death ligand-1 (PD-L1) expression is a key biomarker to identify patients with non-small cell lung cancer who may have an enhanced response to anti-programmed cell death-1 (PD-1)/PD-L1 treatment. Such treatments are used in conjunction with PD-L1 diagnostic immunohistochemistry assays. We developed a computer-aided automated image analysis with customized PD-L1 scoring algorithm that was evaluated via correlation with manual pathologist scores and used to determine comparability across PD-L1 immunohistochemistry assays. The image analysis scoring algorithm was developed to quantify the percentage of PD-L1 positive tumor cells on scans of whole-slide images of archival tumor samples from commercially available non-small cell lung cancer cases, stained with four immunohistochemistry PD-L1 assays (Ventana SP263 and SP142 and Dako 22C3 and 28-8). The scans were co-registered and tumor and exclusion annotations aligned to ensure that analysis of each case was restricted to comparable tissue areas. Reference pathologist scores were available from previous studies. F1, a statistical measure of precision and recall, and overall percentage agreement scores were used to assess concordance between pathologist and image analysis scores and between immunohistochemistry assays. In total, 471 PD-L1-evalulable samples were amenable to image analysis scoring. Image analysis and pathologist scores were highly concordant, with F1 scores ranging from 0.8 to 0.9 across varying matched PD-L1 cutoffs. Based on F1 and overall percentage agreement scores (both manual and image analysis scoring), the Ventana SP263 and Dako 28-8 and 22C3 assays were concordant across a broad range of cutoffs; however, the Ventana SP142 assay showed very different characteristics. In summary, a novel automated image analysis scoring algorithm was developed that was highly correlated with pathologist scores. The algorithm permitted quantitative comparison of existing PD-L1 diagnostic assays, confirming previous findings that indicate a high concordance between the Ventana SP263 and Dako 22C3 and 28-8 PD-L1 immunohistochemistry assays.
Project description:Programmed death ligand 1 (PD-L1) immunohistochemistry (IHC) assays are widely used for complementary or companion diagnostic purposes during treatment with immune checkpoint inhibitors. However, limited information is available on the clinical reliability of the PD-L1 IHC assay using small biopsy samples.Participants included 46 patients with nonsmall cell lung cancer who underwent PD-L1 testing using 3 PD-L1 IHC assays (22C3, SP142, and SP263) for both small biopsy samples and surgical specimens from November 2017 to June 2018. The PD-L1 IHC assay results were analyzed with cut-off values of 1%, 5%, 10%, and 50%. The PD-L1 IHC results obtained from the surgical specimens were regarded as the reference values.The 22C3, SP142, and SP263 PD-L1 IHC assays were performed in 26 (57%), 20 (43%), and 46 (100%) patients, respectively. Biopsy methods included radial probe endobronchial ultrasound using a guide sheath, endobronchial ultrasound-guided transbronchial needle aspiration, bronchoscopic biopsy, and percutaneous needle aspiration in 26 (57%), 4 (9%), 12 (25%), and 4 (9%) patients, respectively. The 22C3, SP142, and SP263 PD-L1 assays had concordance rates of 73-96, 65-80, and 72%-91%, respectively, compared with the reference values.PD-L1 testing with 3 commercial PD-L1 IHC assays using small biopsy samples is reliable in patients with nonsmall cell lung cancer.
Project description:AIMS:Programmed death-1/programmed death ligand 1 (PD-1/PD-L1) inhibitor therapy is accompanied by companion or complementary PD-L1 testing in some tumour types. We investigated utilisation of the Dako PD-L1 IHC 28-8 and 22C3 pharmDx assays and the Ventana PD-L1 (SP142) assay and evaluated concordance between the 28-8 and 22C3 assays in a real-world cohort of patients tested at a single US national reference laboratory. METHODS:NeoGenomics Laboratories performed PD-L1 testing on tumour samples between October 2015 and March 2018. PD-L1 test results were matched with patient characteristics using unique identifiers. Concordance between the 28-8 and 22C3 assays was evaluated in matched tumour samples. Data were evaluated across multiple tumour types and in subgroups of patients with lung cancer, melanoma, squamous cell carcinoma of the head and neck, and urothelial carcinoma. RESULTS:62 180 individual PD-L1 tests were conducted on samples from 55 652 patients. PD-L1 test volume increased ~10-fold over the period evaluated. Test failure rates were typically low, and test turnaround time (TAT) ranged between 2 and 4 days. Concordance between the 28-8 and 22C3 assays was strong in the overall population and across tumour type subgroups (Kendall's tau correlations of 0.94 and 0.92-0.98, respectively). CONCLUSIONS:Test failure rates for PD-L1 tests were low and TAT remained reasonable despite marked increases in test volume. Concordance was high between the 28-8 and 22C3 assays across a range of tumour types and biopsy locations. These findings add to the literature showing high concordance between the 28-8 and 22C3 assays.
Project description:PURPOSE:We provide a comparison between 22C3 pharmDx and SP263 assay, for evaluating programmed death ligand 1 (PD-L1) expression in advanced gastric cancer (GC) patients. Materials and Methods:The PD-L1 immunohistochemistry by 22C3 pharmDx and SP263 assays was performed in the center of the tumor (CT) and invasive margin (IM) in 379 GC tissues using tissue microarrays and interpreted as combined positive score (CPS) and tumor proportion score (TPS). Of the total samples, 55 samples were independently reviewed by five pathologists. RESULTS:The two assays showed a high correlation in both the CPS and TPS. At a CPS ? 1 cut-off, 219 (57.8%) and 231 (60.9%) GCs were positive for PD-L1 with the 22C3 and SP263 assays, and at ? 10 cut-off, 37 (9.8%) and 36 (9.5%) GCs were positive, respectively. The overall percent agreement (OPA) was greater than 90% with CPS ? 1 and ? 10 cut-offs, and TPS ? 1% and ? 10% cut-offs. There was higher OPA between the two assays with a CPS cut-off ? 10 (99.2%) than ? 1 (94.7%). The percent agreement between the CT and IM was higher with a CPS cut-off ? 10 (92.9%) than ? 1 (77.6%). Patient with positive expression at CPS ? 5 cut-off had a significantly better outcomes in both assays. Interobserver variability among five pathologists was higher than the assay variability. CONCLUSION:Two assays for PD-L1 expression in GC showed high agreement. These results provide guidance for selecting eligible patients with GC for pembrolizumab treatment.
Project description:Programmed death-ligand 1 (PD-L1) expression on tumor cells (TC) or tumor-infiltrating immune cells (IC) correlated in several studies with PD-L1/programmed death-1 (PD-1) checkpoint inhibitor efficacy. Since June 2018, a positive PD-L1 status is required for atezolizumab or pembrolizumab treatment of patients with advanced or metastasized urothelial bladder cancer, who are ineligible for cisplatin-containing therapy. We examined technical comparability and inter-reader agreement of four clinically developed PD-L1 assays in locally advanced disease. Archived, formalin-fixed, paraffin-embedded sections from 30 patients (73.3% cystectomies, 26.7% transurethral resections) were stained by PD-L1 immunohistochemistry using VENTANA SP142, VENTANA SP263, DAKO 22C3, and DAKO 28-8 at two sites per manufacturers' protocols and scored blinded at five sites for PD-L1 expression on IC (% per tumor area) and TC (%). Small, non-significant inter-assay differences were observed for IC. For TC, SP142 showed significantly lower staining percentages. Pairwise comparisons revealed -?0.3 to 1.6% differences in adjusted means between assays for IC, and for TC, -?10.5 to -?7.8% (SP142 versus others) and -?1.9 to 2.7% (other comparisons). Inter-reader and inter-assay agreement was moderate to high for both IC and TC. Allocation to binary cutoffs (1%, 5%, 10%) showed substantial to high Kappa agreement scores (0.440-0.923) for IC and TC between assays for each reader. This first multicenter study, with five independent readers blinded with respect to the assay used, suggests that all four currently clinically relevant assays are analytically similar for evaluation of PD-L1-stained IC and three (SP263, 22C3, and 28-8) for PD-L1-stained TC. Inter-observer agreement for trained readers in scoring of both IC and TC positivity was generally high.
Project description:BACKGROUND:Studies have indicated that programmed death ligand 1 (PD-L1) expression may have utility as a predictive biomarker in patients with advanced/metastatic urothelial carcinoma (UC). Different immunohistochemical (IHC) assays are in development to assess PD-L1 expression on tumor cells (TCs) and tumor-infiltrating immune cells (ICs). METHODS:In this post hoc analysis of the single-arm, phase 1/2 Study 1108 (NCT01693562), PD-L1 expression was evaluated from tumor samples obtained prior to second-line treatment with durvalumab in patients with advanced/metastatic UC using the VENTANA (SP263) IHC Assay. The primary objective was to determine whether the TC ? 25%/IC ? 25% algorithm (i.e., cutoff of ? 25% TC or ? 25% IC with PD-L1 staining at any intensity above background) was optimal for predicting response to durvalumab. PD-L1 expression data were available from 188 patients. RESULTS:After a median follow-up of 15.8 and 14.6 months, higher PD-L1 expression was associated with longer overall survival (OS) and progression-free survival (PFS), respectively, with significant separation in survival curves for PD-L1-high and-low expressing patients for the TC ? 25%/IC ? 25% cutoff (median OS: 19.8 vs 4.8 months; hazard ratio: 0.46; 90% confidence interval: 0.33, 0.639). OS was also prolonged for PD-L1-high compared with-low patients when samples were categorized using TC/IC combined positive score ? 10 and IC? 5% cutoffs. In multivariate analysis, IC but not TC PD-L1 expression was significantly associated with OS, PFS, and objective response rate (P < 0.001 for each), although interaction analysis showed similar directionality of benefit for ICs and TCs. CONCLUSIONS:These findings support the utility of a combined TC/IC algorithm for predicting response to durvalumab in patients with UC, with the TC? 25%/IC? 25% cutoff optimal when used with the VENTANA (SP263) IHC Assay.
Project description:BACKGROUND:Numerous studies indicate that higher tumour programmed cell death ligand-1 (PD-L1) expression is associated with greater response to anti-programmed cell death-1 (PD-1)/PD-L1 immunotherapy in non-small cell lung cancer (NSCLC). In the era of precision medicine, there is a need to provide reliable, standardised training for pathologists to improve their accuracy of interpretation and scoring, as the results are used directly to inform clinical decisions. Here we present findings regarding reader reproducibility of PD-L1 tumour cell (TC) staining scoring for NSCLC using a PD-L1 e-trainer tool as part of a PD-L1 immunohistochemistry reader training course. METHODS:The PD-L1 training course was developed based on the use of VENTANA PD-L1 (SP263) and Dako PD-L1 IHC PharmDx 22C3 stained NSCLC samples in combination with a PD-L1 e-trainer tool. Five-hundred formalin-fixed, paraffin-embedded archival samples were obtained from commercial sources and stained for PD-L1. Slides were scored by two expert pathologists, then scanned to produce digital images and re-scored. Thirty-three cases were selected and sorted into three sets: a training set and two self-assessment tests (pre-test and 'competence' test). Participants (all selected board-certified pathologists) received face-to-face training including use of an e-trainer tool. Statistical analyses were performed using the competence test set. Overall percentage agreement (OPA) was assessed between the participant pathologists' registered scores and the reference scores assigned by expert pathologists at clinically relevant PD-L1 cut-offs (?1%, ?25% and???50%). RESULTS:Seven sessions were held and 69 participant pathologists completed the training. Inter-reader concordance indicated high OPA (85-95%) for PD-L1 TC scoring at clinically relevant cut-offs, with Fleiss' Kappa >?0.5. CONCLUSIONS:Use of this web-based training tool incorporated into classroom-style training was associated with an overall moderately good level of inter-reader reproducibility at key cut-offs for TC PD-L1 expression testing in NSCLC. Overall, the online training tool offers a means of standardised training for practising pathologists in a clinical setting.
Project description:Programmed death ligand-1 (PD-L1) immunohistochemistry is used to guide treatment decisions regarding the use of checkpoint immunotherapy in the management of urothelial carcinoma of the bladder and hypopharyngeal (HP) squamous cell carcinoma. With increasing PD-L1 testing options, a need has arisen to assess the analytical comparability of diagnostic assays in order to develop a more sustainable testing strategy. Using tissue microarrays, PD-L1 expression in tumor cells (TCs) and immune cells (ICs) was manually scored in 197 cases and 27 cases of bladder and HP cancer, respectively. Three commercial kits (Ventana SP263, Ventana SP142, Dako 22C3) and 1 platform-independent test (Cell Signalling Technologies E1L3N) were utilized. Across the 3 commercially available clones, 14% and 74% of urothelial carcinomas were positive and negative, respectively, whereas 7% and 78% of HP carcinomas were positive and negative, respectively. Twelve percent of bladder and 15% HP cases showed discrepant PD-L1 classification results. Regardless of the scoring algorithm used, E1L3N provided comparable PD-L1 staining results. Fleiss' kappa and intraclass correlation coefficient (ICC) analyses demonstrated substantial agreement among all antibody clones (k=0.639 to 0.791) and excellent reliability among SP263, 22C3, and E1L3N antibodies (ICC, 0.929 to 0.949) in TC staining. Compared with the other 3 clones, SP142 TC staining was lower with only moderate correlation (ICC, 0.500 to 0.619). Generally, the reliability of immune cell staining was lower compared with TC staining (ICC, 0.519 to 0.866). Our results demonstrate good analytic comparability of all 4 antibodies. The results are encouraging and support growing optimism in the pathology and oncology communities concerning strategies in PD-L1 assay use.
Project description:A meeting among expert pathologists was held in 2019 in Rome to verify the results of the previous harmonization efforts on the PD-L1 immunohistochemical testing by scoring a representative series of non-small cell lung cancer (NSCLC) digital slides. The current paper shows the results of this digital experimental meeting and the expertise achieved by the community of Italian pathologists. PD-L1 protein expression was determined using tumor proportion score (TPS), i.e., the percentage of viable tumor cells showing partial or complete membrane staining at any intensity. The gold standard was defined as the final PD-L1 score formulated by a panel of seven lung committed pathologists. PD-L1 status was clustered in three categories, namely negative (TPS < 1), low (TPS 1-49%), and high (TPS ? 50%). In 23 cases (71.9%) PD-L1 staining was performed using the companion diagnostic 22C3 pharmDx kit on Dako Autostainer, while in nine (28.1%) cases it was performed using the SP263 Ventana kit on BenchMark platform. A complete PD-L1 scoring agreement between the panel of experts and the participants was reached in 57.1% of cases, whereas a minor disagreement in 16.1% of cases was recorded. Italian pathologists performed best in strong positive cases (i.e., tumor proportion score TPS > 50%), whereas only 10.8% of disagreement with the gold standard was observed, and 55.6% regarded a single challenging case. The worst performance was achieved in the negative cases, with 32.0% disagreement. A significant difference resulted from the analysis of the data separated by the different clones used: 22.3% and 38.1% disagreement (p = 0.01) was found in the group of cases analyzed by 22C3 and SP263 antibody clones, respectively. In conclusion, this workshop record proposed the application of a digital pathology platform to share controversial cases in educational meetings as an alternative possibility for improving the interpretation and reporting of specific histological tools. Due to the crucial role of PD-L1 TPS for the selection of patients for immunotherapy, the identification of unconventional approaches as virtual slides to focus experiences and give more detailed practical verifications of the standard quality reached may be a considerable option.