Regulatory approval of pembrolizumab for treatment of gastric and gastroesophageal junction (G/GEJ) adenocarcinoma required a reproducible scoring method for use of programmed death ligand-1 (PD-L1) ...protein expression as a companion diagnostic to identify likely responders to therapy.
To develop an immunohistochemical scoring algorithm that includes PD-L1 expression for tumor and immune cells, that is, the combined positive score.
Four previously treated tumor types in the KEYNOTE-012 and KEYNOTE-028 studies were analyzed descriptively with a version of the PD-L1 immunohistochemical 22C3 pharmDx assay labeled for investigational use only to determine the relative importance of PD-L1 expression in tumor versus immune cells as a biomarker for pembrolizumab response. A combined positive score was developed as a novel scoring method and was compared with the tumor proportion score in cohort 1 from the KEYNOTE-059 study (G/GEJ cancer). External reproducibility was assessed.
Per combined positive score cutoff of 1 or more, the prevalence of PD-L1 expression in patients with G/GEJ cancer was 57.6% (148 of 257 patients), with reasonable enrichment of responses (odds ratio, 2.8). Per tumor proportion score cutoff of 1% or more, prevalence was 12.5% (32 of 257 patients), with minimal enrichment (odds ratio, 1.4). External reproducibility assessments demonstrated interpathologist overall agreement of 96.6% (591 of 612; 95% CI, 94.0%-98.7%) and intrapathologist overall agreement of 97.2% (595 of 612; 95% CI, 95.3%-98.9%).
Combined positive score is a robust, reproducible PD-L1 scoring method that predicts response to pembrolizumab in patients with G/GEJ cancer. This novel scoring method supported US Food and Drug Administration approval of pembrolizumab as third-line therapy for G/GEJ cancer and has facilitated investigation in other indications.
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DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
We conducted an analysis across multiple PD-L1 combined positive score (CPS) indications to establish concordance of a 22C3 antibody-based laboratory-developed test (LDT) on the Ventana BenchMark XT ...or BenchMark ULTRA platform and the regulatory-approved PD-L1 IHC 22C3 pharmDx in cervical cancer (CC), esophageal squamous cell carcinoma (ESCC), head and neck squamous cell carcinoma (HNSCC), triple-negative breast cancer (TNBC), and urothelial carcinoma (UC). Tumor specimens from each tumor type were stained with 22C3 antibody and scored using the 22C3 antibody-based LDT, and scores were compared with those using PD-L1 IHC 22C3 pharmDx. PD-L1 status was measured by the pathologist using CPS as a continuous score and using clinically relevant cutoffs (CC, ≥1 and ≥10; HNSCC, ≥1 and ≥20; ESCC, TNBC, and UC, ≥10). The agreement between the BenchMark platforms and PD-L1 IHC 22C3 pharmDx was assessed by intraclass correlation coefficient (ICC) and a contingency table for clinical interpretation. A total of 522 samples were evaluated for the pan-tumor analysis (CC, n = 77; ESCC, n = 80; HNSCC, n = 126; TNBC, n = 118, UC, n = 121). Most clinical interpretations of PD-L1 status were concordant between the BenchMark XT and PD-L1 IHC 22C3 pharmDx for all five tumor types with regard to negative percentage agreement (NPA; 83-97%), positive percentage agreement (PPA; 86-100%), and overall percentage agreement (OPA; 90-97%); the ICC by tumor type was high (≥0.88). Importantly, the pan-tumor ICC was 0.95 (95% CI 0.94-0.96). Thirty additional TNBC samples were evaluated using the BenchMark ULTRA and PD-L1 IHC 22C3 pharmDx; the NPA, PPA, and OPA were 100%. The 22C3 antibody-based LDT on Ventana BenchMark XT and BenchMark ULTRA platforms demonstrated high concordance with the regulatory-approved PD-L1 IHC 22C3 pharmDx across multiple tumor types. These findings suggest the comparability of PD-L1 IHC 22C3 pharmDx with an LDT based on the 22C3 antibody.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The Blueprint Programmed Death Ligand 1 (PD-L1) Immunohistochemistry (IHC) Assay Comparison Project is an industrial-academic collaborative partnership to provide information on the analytical and ...clinical comparability of four PD-L1 IHC assays used in clinical trials.
A total of 39 NSCLC tumors were stained with four PD-L1 IHC assays (22C3, 28-8, SP142, and SP263), as used in the clinical trials. Three experts in interpreting their respective assays independently evaluated the percentages of tumor and immune cells staining positive at any intensity. Clinical diagnostic performance was assessed through comparisons of patient classification above and below a selected expression cutoff and by agreement using various combinations of assays and cutoffs.
Analytical comparison demonstrated that the percentage of PD-L1–stained tumor cells was comparable when the 22C3, 28-8, and SP263 assays were used, whereas the SP142 assay exhibited fewer stained tumor cells overall. The variability of immune cell staining across the four assays appears to be higher than for tumor cell staining. Of the 38 cases, 19 (50.0%) were classified above and five (13%) were classified below the selected cutoffs of all assays. For 14 of the 38 cases (37%), a different PD-L1 classification would be made depending on which assay/scoring system was used.
The Blueprint PD-L1 IHC Assay Comparison Project revealed that three of the four assays were closely aligned on tumor cell staining whereas the fourth showed consistently fewer tumor cells stained. All of the assays demonstrated immune cell staining, but with greater variability than with tumor cell staining. By comparing assays and cutoffs, the study indicated that despite similar analytical performance of PD-L1 expression for three assays, interchanging assays and cutoffs would lead to “misclassification” of PD-L1 status for some patients. More data are required to inform on the use of alternative staining assays upon which to read different specific therapy-related PD-L1 cutoffs.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Summary Background Expression of PD-L1 has been shown to be upregulated in some patients with gastric cancer. As part of the phase 1b KEYNOTE-012 study, we aimed to assess the safety and activity of ...the anti-PD-1 antibody pembrolizumab in patients with PD-L1-positive recurrent or metastatic adenocarcinoma of the stomach or gastro-oesophageal junction. Methods This study was a multicentre, open-label, phase 1b trial done at 13 cancer research centres in the USA, Israel, Japan, South Korea, and Taiwan. We enrolled patients with PD-L1-positive recurrent or metastatic adenocarcinoma of the stomach or gastro-oesophageal junction. Patients received intravenous pembrolizumab at 10 mg/kg once every 2 weeks for 24 months or until progression or unacceptable toxic effects occurred. Response was assessed every 8 weeks in accordance with Response Evaluation Criteria in Solid Tumors version 1.1. The primary objectives were safety in patients who received at least one dose of pembrolizumab and the proportion of patients achieving overall responses in patients who received at least one pembrolizumab dose and who either had a post-baseline scan or who discontinued therapy because of clinical disease progression or a treatment-related adverse event before the first post-baseline scan. The study is registered with ClinicalTrials.gov , number NCT01848834 , and is ongoing but no longer enrolling patients. Findings From Oct 23, 2013, to May 5, 2014, 39 patients were enrolled. 36 were evaluable for response by central assessment. Eight (22%, 95% CI 10–39) patients were judged to have had an overall response at central review; all responses were partial. All 39 patients were included in the safety analyses. Five (13%) patients had a total of six grade 3 or 4 treatment-related adverse events, consisting of two cases of grade 3 fatigue, one case each of grade 3 pemphigoid, grade 3 hypothyroidism, and grade 3 peripheral sensory neuropathy, and one case of grade 4 pneumonitis. No treatment-related deaths occurred. Interpretation In this population of patients with recurrent or metastatic PD-L1-positive gastric cancer, pembrolizumab had a manageable toxicity profile and promising antitumour activity, warranting further study in phase 2 and 3 trials. Funding Merck & Co.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Purpose Expression of programmed death-ligand 1 (PD-L1) is a potential predictive marker for response and outcome after treatment with anti-programmed death 1 (PD-1). This study explored the ...relationship between anti-PD-1 activity and PD-L1 expression in patients with advanced melanoma who were treated with pembrolizumab in the phase Ib KEYNOTE-001 study (clinical trial information: NCT01295827). Patients and Methods Six hundred fifty-five patients received pembrolizumab10 mg/kg once every 2 weeks or once every 3 weeks, or 2 mg/kg once every 3 weeks. Tumor response was assessed every 12 weeks per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 by independent central review. Primary outcome was objective response rate. Secondary outcomes included progression-free survival (PFS) and overall survival (OS). Membranous PD-L1 expression in tumor and tumor-associated immune cells was assessed by a clinical trial immunohistochemistry assay (22C3 antibody) and scored on a unique melanoma (MEL) scale of 0 to 5 by one of three pathologists who were blinded to clinical outcome; a score ≥ 2 (membranous staining in ≥ 1% of cells) was considered positive. Results Of 451 patients with evaluable PD-L1 expression, 344 (76%) had PD-L1-positive tumors. Demographic and staging variables were equally distributed among PD-L1-positive and -negative patients. An association between higher MEL score and higher response rate and longer PFS (hazard ratio, 0.76; 95% CI, 0.71 to 0.82) and OS (hazard ratio, 0.76; 95% CI, 0.69 to 0.83) was observed ( P < .001 for each). Objective response rate was 8%, 12%, 22%, 43%, 57%, and 53% for MEL 0, 1, 2, 3, 4, and 5, respectively. Conclusion PD-L1 expression in pretreatment tumor biopsy samples was correlated with response rate, PFS, and OS; however, patients with PD-L1-negative tumors may also achieve durable responses.
A companion diagnostic assay was codeveloped by Dako for pembrolizumab non-small-cell lung cancer clinical trials to detect PD-L1 expression by immunohistochemistry (IHC). This automated IHC assay ...has been analytically verified and validated using Dako's autostainer Link 48 and 22C3 mouse anti-PD-L1 monoclonal antibody to detect the PD-L1 expression in formalin-fixed paraffin-embedded human tumor tissue specimens. The PD-L1 22C3 IHC assay was optimized for high sensitivity and specificity. Repeatability and reproducibility studies were conducted at Dako and at 3 Clinical Laboratory Improvement Amendments certified laboratories during assay development. The studies included: intersite and intrasite, interobserver and intraobserver, interinstrument, interoperator, interday, and interlot, and intraday and intrarun. All precision studies performed at Dako and external laboratories achieved >85% point-estimate agreements for all 3 agreement types (negative, positive, and overall). A clinical cutoff (tumor proportion score ≥50%) of PD-L1 expression was determined and evaluated through a phase 1 clinical trial (KEYNOTE-001) for advanced non-small-cell lung cancer patients treated with pembrolizumab. The treatment effect of pembrolizumab in the 61 subjects who had a tumor PD-L1 of tumor proportion score ≥50% was substantial, with an overall response rate of 41% (95% confidence interval, 28.6-54.3) as compared with 20.6% (95% confidence interval, 15.5-26.5) observed in the 223 subjects irrespective of PD-L1 status. PD-L1 IHC 22C3 pharmDx is a sensitive, precise, and robust companion diagnostic assay, which will facilitate safe and effective use for pembrolizumab in cancer patients.
Tumor proportion score (TPS) and combined positive score (CPS includes immune cells), 2 methods for scoring programmed death ligand 1 (PD-L1) expression, have been used in clinical trials ...investigating the immune checkpoint inhibitor pembrolizumab in head and neck squamous cell carcinoma (HNSCC). These trials resulted in regulatory approval for pembrolizumab in the first- and second-line setting outside the United States. We performed a post hoc analysis of the KEYNOTE-040 study (NCT02252042) to determine whether CPS is a practical and suitable alternative scoring method to TPS. In KEYNOTE-040, patients with metastatic HNSCC received pembrolizumab or investigator choice of standard of care (SOC). The relative utility and equivalence of CPS ≥ 50 and TPS ≥ 50% for defining PD-L1 expression status in patients with HNSCC and comparability of scoring methods by tandem receiver operating characteristic (ROC) analysis were analyzed. The cutoff for each method was also evaluated. CPS ≥ 50 appeared equivalent to TPS ≥ 50% for predicting objective response rate (ORR), overall survival, and progression-free survival. ORR for pembrolizumab versus SOC was 26.2 versus 8.5% for TPS ≥ 50%, 28.1 versus 7.7% for CPS ≥ 50, 10.6 versus 11.6% for TPS < 50%, and 10.0 versus 12.0% for CPS < 50. Tandem ROC analysis showed that TPS 50% and CPS 50 maximized delta Youden index and suggested that CPS is more sensitive than TPS at lower cutoffs (i.e., CPS ≥ 1). In conclusion, CPS 50 can be used interchangeably with TPS 50% to determine PD-L1 status in patients with HNSCC. CPS may be more sensitive than TPS at lower cutoffs.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Context .- Programmed death ligand-1 (PD-L1) expression by tumors may enable them to avoid immunosurveillance. Objective .- To develop a PD-L1 immunohistochemical assay using the 22C3 anti-PD-L1 ...murine monoclonal antibody on the Dako platform as a possible companion diagnostic for pembrolizumab in patients with non-small cell lung cancer. Design .- Tumor samples from 146 patients with non-small cell lung cancer treated with pembrolizumab in KEYNOTE-001 and for whom response data were available were scored according to their staining intensity by a single pathologist using 4 methods: percentage of tumor cells staining at any intensity (PS1), moderate/strong intensity (PS2), strong intensity (PS3), and H-score (PS1 + PS2 + PS3). The cutoff score for predicting response to pembrolizumab was determined using receiver operating characteristic analysis. Progression-free and overall survival were assessed in patients with measurable disease per Response Evaluation Criteria in Solid Tumors, version 1.1 (n = 146). Results .- The 4 scoring methods assessed performed similarly; PS1 with a 50% cutoff score is the simplest and easiest method to implement in practice. Response to pembrolizumab was observed in 19 of 44 patients (43%) with a PS1 score of 50% or higher and 8 of 102 patients (8%) with PS1 lower than 50% (odds ratio, 8.93). Median progression-free and overall survival was 4.0 months and not yet reached, respectively, for patients with a PS1 of 50% or higher, and 2.1 and 6.1 months, respectively, for those with PS1 lower than 50%. Conclusion .- The PD-L1 immunohistochemical assay shows the potential for enrichment of trial populations and as a companion diagnostic tool in non-small cell lung cancer.
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DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
Pembrolizumab, an anti–programmed death 1 monoclonal antibody, underwent a rapid clinical development program for the treatment of patients with malignancies in parallel to the development of a ...companion diagnostic for detecting programmed death ligand 1 (PD-L1) expression, which was considered to be a likely biomarker for response and cancer outcome. When investigating outcomes in patients with non–small cell lung cancer (NSCLC) treated with pembrolizumab, PD-L1 tumor proportion score (TPS) was initially identified as a marker of clinical efficacy, with a cutoff of ≥ 50%. This threshold was later reduced to TPS ≥ 1%, which demonstrated that pembrolizumab offered a clinical benefit in a broader population of patients with PD-L1–expressing tumors. As new evidence emerged, it also became clear that immune cell PD-L1 expression has an important role in predicting tumor response in patients treated with pembrolizumab; the combined positive score (CPS), which accounts for both tumor and immune cell PD-L1 expression, was then applied in clinical studies for indications outside of NSCLC. This review summarizes the outcomes of landmark studies in the KEYNOTE clinical development program that investigated the efficacy of pembrolizumab in patients with a variety of malignancies, the relative outcomes when patients were stratified by PD-L1 status, and how these observations have influenced the approved indications for pembrolizumab.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
- With the abundance of therapeutics targeted against programmed death receptor-1 and its ligand (PD-L1) that are currently approved or in clinical development, there is interest in identifying those ...patients most likely to respond to these drugs. Expression of PD-L1 may be an indicator of an initial and robust inflammatory response to the presence of tumor cells. Therefore, tumors that express PD-L1 may be the most likely to respond to therapies that interrupt the negative feedback mechanism that leads to PD-L1 upregulation.
- To develop a prototype immunohistochemistry assay using the anti-PD-L1 antibody clone 22C3.
- The assay was developed and optimized using commercially available reagents and archival tumor-bank tissue.
- The optimized immunohistochemistry method had high precision and reproducibility. Using the prototype assay in 142 non-small cell lung cancer and 79 melanoma archival tumor-bank tissue samples, PD-L1 staining was observed at the plasma membrane of nucleated tumor and nontumor cells and, in some cases, as a distinct lichenoid pattern at the tumor-stroma border. Using a preliminary scoring method, 56% (80 of 142) of non-small cell lung cancer and 53% (42 of 79) of melanoma samples were defined as PD-L1
based on a modified H-score of 1 or more or the presence of a distinctive staining pattern at the tumor-stroma interface.
- The immunohistochemistry assay using the anti-PD-L1 antibody 22C3 merits further investigation in clinical trials and prevalence assessments to further understand the prognostic and predictive value of PD-L1 expression in cancer.
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