Microsatellite Instability, Epstein–Barr Virus, and Programmed Cell Death Ligand 1 as Predictive Markers for Immunotherapy in Gastric Cancer

Immunotherapy benefits selected cases of gastric cancer (GC), but the correlation between biomarkers and prognosis is still unclear. Fifty-two patients with GC who underwent immunotherapy were enrolled from June 2016 to December 2020. Their clinical features and biomarkers—microsatellite instability-high (MSI-H), programmed cell death ligand 1 (PD-L1) combined positive score (CPS), and Epstein–Barr encoding region (EBER)—were analyzed. Eight patients had MSI-H, five patients had EBER, 29 patients had CPS ≥ 1, and 20 patients had no biomarker. The overall response rates (ORRs) of the MSI-H, EBER, PD-L1 CPS ≥ 1, and all-negative group were 75%, 60%, 44.8%, and 15%, respectively. Compared with that of the all-negative group, progression-free survival (PFS) was better in the MSI-H (p = 0.018), CPS ≥ 5 (p = 0.012), and CPS ≥ 10 (p = 0.006) groups, but not in the EBER (p = 0.2) and CPS ≥ 1 groups (p = 0.35). Ten patients had combined biomarkers, CPS ≥ 1 with either MSI-H or EBER. The ORRs were 66.7% for CPS ≥ 1 and MSI-H and 75% for CPS ≥ 1 and EBER. PFS was better in patients with combined biomarkers (p = 0.01). MSI-H, EBER, and CPS are useful biomarkers for predicting the efficacy of immunotherapy.

Programmed Death Ligand-1 Expression Is Associated With Poorer Survival in Anal Squamous Cell Carcinoma

Context.— Upregulation of programmed death ligand-1 (PD-L1), an immunoregulatory protein, is associated with an adverse outcome in several malignancies. Very few studies have evaluated PD-L1 expression in invasive anal squamous cell carcinoma (ASCC). Objective.— To assess PD-L1 expression in patients with ASCC and correlate it with clinicopathologic factors and clinical outcomes. Design.— Fifty-one cases of ASCC were immunostained for PD-L1. PD-L1 expression by combined positive score and tumor proportion score was correlated with age, gender, HIV status, HIV viral load, CD4 count, stage, and outcomes. Kaplan-Meier curves for overall survival were plotted and compared using the log-rank test. Cox regression analysis was performed to identify significant prognostic factors (2-tailed P < .05 was considered statistically significant). Results.— PD-L1 was positive in 24 of 51 cases (47%) by combined positive score and in 18 of 51 (35%) by tumor proportion score. The median cancer-specific survival and 5-year overall survival were significantly lower in PD-L1+ patients. Age, gender, HIV status, HIV viral load, stage, and cancer progression were not significantly different between the two groups. CD4 count of more than 200/μL was significantly higher in PD-L1+ patients. PD-L1+ status remained statistically significant for worse overall survival on multivariate analysis. Conclusions.— PD-L1+ status is an independent adverse prognostic factor for overall survival in ASCC. This study highlights the potential of PD-L1 targeted therapy in better management of ASCC.

Comparison of programmed death ligand 1 immunostaining for pancreatic ductal adenocarcinoma between paired cytological and surgical samples

Objectives: Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis with surgery or chemotherapy. Programmed death ligand 1 expression (PD-L1) immunotherapy has been successful for treating lung and other cancers with PD-L1 expression. However, in many unresectable PDAC cases, cytological samples are the only available tissues for PD-L1 testing. The aim of this study is to retrospectively compare the expression of PD-L1 using cytological and surgical samples. Material and Methods: Paired formalin-fixed cell blocks and surgical samples from the same patients with confirmed diagnoses of PDAC (n = 28) were sectioned for PD-L1 immunohistochemistry. Using tumor proportion score (TPS) and combined positive score (CPS) to evaluate paired cell blocks and surgical samples, we counted and analyzed the data. Results: With TPS, the PD-L1 was expressed in 9/28 (32%) of PDAC surgical samples and in 9/28 (32%) of paired cytological samples. Overall, the PD-L1 expression had a correlation of 26/28 (93%). With CPS, the PD-L1 was expressed in 20/28 (71%) of PDAC surgical samples and in 16/28 (57%) of paired cytological samples. The PD-L1 expression had a correlation of 20/28 (71%) and a discrepancy of 8/28 (29%). The PD-L1 expression was significantly higher in moderately-differentiated PDAC than in well-differentiated with TPS. Conclusion: Cytological samples are useful for evaluating PD-L1 expression with TPS because the concordant rate was 93%. With CPS, cytological samples are limited due to the scant inflammatory cells with the concordant rate of 71%. Extensive sampling of the pancreatic tumor may improve the detection of immune cells expressing PD-L1 in cytological samples. With TPS, PD-L1 expression was significantly higher in moderate-differentiation of PDAC than in poor- and well-differentiation.

60 Use of the Combined Positive Score (CPS) with the companion diagnostic PD-L1 IHC 22C3 pharmDx provides precise evaluation of PD-L1 expression across multiple tumor indications and cutoffs

BackgroundThe Combined Positive Score (CPS)1 algorithm includes tumor and immune cells for determination of Programed Death-Ligand 1 (PD-L1) protein expression in tumor tissues and has been analytically and clinically validated for use with PD-L1 IHC 22C3 pharmDx across multiple indications and cutoffs.2 PD-L1 22C3 IHC pharmDx is a qualitative immunohistochemical assay using anti-PD-L1, Clone 22C3 to detect PD-L1 in formalin-fixed, paraffin-embedded (FFPE) tumor tissues using Autostainer Link 48. PD-L1 IHC 22C3 pharmDx is FDA-approved as an aid in identifying patients for treatment with KEYTRUDA® for six tumor indications at clinically validated CPS diagnostic cutoffs2: gastric or gastroesophageal junction (GC/GEJ) adenocarcinoma (CPS ≥ 1), cervical cancer (CPS ≥ 1), urothelial carcinoma (CPS ≥ 10), head and neck squamous cell carcinoma (HNSCC) (CPS ≥ 1), esophageal squamous cell carcinoma (ESCC) (CPS ≥ 10)3, and triple-negative breast cancer (TNBC) (CPS ≥ 10).MethodsPrecision of PD-L1 IHC 22C3 pharmDx using CPS was assessed for all six indications at the corresponding clinically validated diagnostic cutoffs and at additional exploratory cutoffs under normal, day-to-day testing conditions. Precision testing included Combined Precision (inter-instrument/operator/run (day)), Intra-Run Repeatability, and Observer (inter-/intra-) Scoring Reproducibility studies. FFPE specimens were stained with PD-L1 IHC 22C3 pharmDx and scored using CPS as described in the package insert.2 Four CPS cutoffs were evaluated: CPS ≥ 1 (GC/GEJ, urothelial carcinoma, ESCC, cervical cancer, HNSCC, TNBC), CPS ≥ 10 (GC/GEJ, urothelial carcinoma, ESCC, TNBC), CPS ≥ 20 (HNSCC), and CPS ≥ 50 (HNSCC). Data were analyzed using negative percent agreement (NPA), positive percent agreement (PPA), and overall agreement (OA) with two-sided 95% percentile bootstrap confidence intervals (CIs) based on PD-L1 binary status at the applicable cutoff(s). For each study, data from each CPS cutoff-indication pair were individually analyzed. Meta-analyses were also performed by pooling data from all indications per (i) study and cutoff, and (ii) per study for all tested cutoffs.ResultsNearly all agreement analyses (142/144) for each CPS cutoff-indication pair showed NPA/PPA/OA point estimates (PE) ≥ 90% and CI lower bounds (CILB) ≥ 85%. Meta-analyses showed PE ≥ 90% for NPA/PPA/OA and CILB ≥ 85% per study and cutoff, and per study for all tested cutoffs. Discordant comparisons accounted for <5% of total comparisons performed for each study type.ConclusionsCPS used with PD-L1 IHC 22C3 pharmDx provides precise evaluation of PD-L1 expression across multiple tumor indications and cutoffs under normal, day-to-day testing conditions.AcknowledgementsWe thank the IUSCC Cancer Center at Indiana University School of Medicine, for the use of the Tissue Procurement and Distribution Core, which provided Dako North America, Inc. service.The data and biospecimens used in this project were provided by US Biolab (Gaithersburg, MD, USA), Sofia Bio LLC (New York, NY, USA), Contract Research Ltd (Charlestown, Nevis), and Centre Hospitalier Universitaire (CHU) de Nice (Nice, France) with appropriate ethics approval and through Trans-Hit Biomarkers Inc. Tissue samples were provided by the Cooperative Human Tissue Network which is funded by the National Cancer Institute. Other investigators may have received specimens from the same subjects. Tissue samples supplied by BioIVT (Hicksville, NY, USA).Trial RegistrationN/AReferencesCPS = (# PD-L1 staining cells (tumor cells, lymphotcytes, macrophages))/(Total # viable tumor cells )×100PD-L1 IHC 22C3 pharmDx [Instructions for Use]. Available at: www.agilent.com/library/eifu. Code SK006. Accessed July 2, 2021ESCC was analytically validated as a subtype of esophageal cancer [2].Ethics ApprovalN/AConsentN/A

Diagnostik und Therapie des Magenkarzinoms

Was ist neu? Molekulare Subtypen Die molekularen Alterationen beim Magenkarzinom wurden umfassend charakterisiert. Darauf basiert eine Einteilung in 4 Subtypen, die sich hinsichtlich ihrer Frequenz in unterschiedlichen Lokalisationen des Magens sowie im biologischen Verhalten und der Prognose unterscheiden. Vorsorge und erbliche Formen Chronische Entzündungen der Schleimhaut (unter dem Einfluss von Helicobacter pylori) spielen bei den Nicht-Kardia-Karzinomen eine zentrale pathogenetische Rolle. Patienten mit ausgedehnter Atrophie oder intestinaler Metaplasie sollten endoskopisch überwacht werden. Bei Risikopersonen sollte Helicobacter pylori eradiziert werden. Ein frühes Erkrankungsalter kann auf eine erbliche Disposition hinweisen (Keimbahnmutationen im E-Cadherin-Gen). Patienten mit hereditärem nicht polypösem kolorektalem Karzinom haben ebenfalls ein erhöhtes Risiko, an Magenkarzinomen zu erkranken. Eine humangenetische Beratung ist in beiden Fällen obligat. Therapie des Magenkarzinoms und des Adenokarzinoms des gastroösophagealen Übergangs Frühkarzinome können unter klar definierten Voraussetzungen mittels endoskopischer Resektion behandelt werden. Lokal fortgeschrittene Magenkarzinome werden mit einer perioperativen Systemtherapie behandelt. Das FLOT-Regime, bestehend aus Folinsäure/5-Fluorouracil, Oxaliplatin und Docetaxel, wurde kürzlich als neuer Standard etabliert. Patienten mit metastasierter Erkrankung profitieren von einer Systemtherapie. Diese führt sowohl zu einer Verlängerung des Überlebens als auch über die Kontrolle der Tumorerkrankung zu einer Verbesserung der Symptomkontrolle und Lebensqualität. Platin-Fluoropyrimidin-Doubletten sind in der ersten Behandlungslinie Standard, im Falle von HER2-Positivität in Kombination mit Trastuzumab. Aktuell wurde Pembrolizumab, ein gegen PD-1 gerichteter Antikörper in Kombination mit einer Platin- und Fluoropyrimidin-basierten Chemotherapie bei Her-2 negativen, metastasierten Adenokarzinomen des gastroösophagealen Übergangs mit einer PD-L1 Expression (Combined Positive Score, CPS ≥ 10) zugelassen. Paclitaxel und der antiangiogene Antikörper Ramucirumab sind zugelassen für die zweite Therapielinie. Die orale Wirkstoffkombination Trifluridin/Tipiracil (TAS-102) steht basierend auf einer Phase-III-Studie seit Kurzem für die Drittlinientherapie zur Verfügung. Epstein-Barr-Virus-positive und Mikrosatelliten-instabile Magenkarzinome sind in besonderem Maße immunogen. Immuncheckpoint-Inhibitoren sind hier hoch wirksam, aber in Europa nicht zugelassen.

345 Phase I/II trial of cabozantinib plus durvalumab in advanced gastroesophageal cancer and other gastrointestinal malignancies (CAMILLA): phase Ib safety and efficacy results

BackgroundCabozantinib is a multi-tyrosine kinase inhibitor primarily targeting VEGFR, MET, and AXL. These targets promote a tumor immune permissive microenvironment. Cabozantinib has demonstrated immunomodulatory properties & clinical synergy when paired with PD-L1 inhibitors such as durvalumab. Here, we present final results of phase Ib of the Camilla trial assessing cabozantinib plus durvalumab in advanced GE adenocarcinoma (GEA), colorectal cancer (CRC), and hepatocellular carcinoma (HCC). This is an investigator-initiated trial funded by Exelixis & Astrazeneca.MethodsPatients were administered cabozantinib + durvalumab in a dose escalation (3+3) then expansion to find the Dose Limiting Toxicities (DLTs), Recommended Phase 2 Dose (RP2D), ORR, PFS, and OS. Subgroup analysis was conducted to assess efficacy in patients with PD-L1 Combined Positive Score (CPS) ≥ 5. Dosing of cabozantinib was 20mg QD, 40mg QD, and 60mg QD PO in the 1st, 2nd, and 3rd cohorts. Dosing of durvalumab was 1500mg IV Q4W in all cohorts. DLT window was 28 days. Treatment beyond progression was allowed following modified RECIST v1.1 criteria.Results35 patients (14F, 21M), median age 53 years (range 27–79) were enrolled. 10 patients had GEA, 20 had CRC, and 5 had HCC; none had MMR deficiency. Median number of prior systemic therapies was 3 (range 0–3). No DLTs were observed during dose escalation. Per mature tolerability data, 11/14 patients receiving cabozantinib 60mg required dose-reduction post cycle 2 to 40mg. RP2D was determined to be cabozantinib 40mg QD plus durvalumab 1500mg Q4W. Of the 247 observed Treatment-Related Adverse Events (TRAEs), 10% (24) were grade≥3. Most common TRAEs were grade 1–2 fatigue (57%), nausea (43%), anorexia (40%), diarrhea (37%), transaminitis (34%), hand-foot syndrome (23%), & weight loss (23%). 2 patients each developed grade≥3 fatigue, weight loss, & abdominal pain. Overall, 30 pts were evaluable for efficacy. ORR 26.7%; DCR 83.3%; median PFS 4.5 months; 6-month PFS 36.7%; and median OS 9.1 months. 12 patients had PD-L1 CPS ≥5. In this subgroup, ORR 33.33%; DCR 91.67%; median PFS 6.13 months; 6-month PFS 50%; and median OS was not reached.ConclusionsCabozantinib plus durvalumab demonstrated promising efficacy and was fairly tolerated without new safety signals. High PD-L1 expression defined as CPS ≥ 5 was associated with improved efficacy & survival. The phase II multi-cohort part of the trial is currently ongoing.Trial RegistrationNCT03539822Ethics ApprovalThe study was approved by the participating site’s local IRB.ConsentAll study participants granted a written informed consent prior to treatment initiation.

Harmonization of PD-L1 Immunohistochemistry and mRNA Expression Scoring in Metastatic Melanoma: A Multicenter Analysis

Background: Melanoma is a type of cancer with robust response to immunotherapy. Programmed death ligand 1 (PD-L1) testing is not required to treat patients, but most studies have demonstrated correlations between PD-L1 expression and treatment response using various assays and scoring methods. This multicenter study aimed to harmonize PD-L1 immunohistochemistry (IHC) and scoring in melanoma. To provide a reference for PD-L1 expression independent of the IHC protocol, PD-L1 mRNA expression was determined via RNAscope, then compared to IHC.Methods: Standardized PD-L1 assays (22C3, 28–8, SP142, and SP263) and laboratory-developed tests (clone QR1 and 22C3) were evaluated on three IHC platforms using a training set of 7 cases. mRNA expression was determined via RNAscope (CD274/PD-L1 probe) and analyzed by image analysis. PD-L1 IHC findings were scored by seven blinded pathologists using the tumor proportion score (TPS), combined positive score (CPS), and MELscore. After the study, a standardized method was proposed; this was validated by three blinded pathologists on a set of 40 metastatic melanomas that were stained using three protocols.Results: Concordances among various antibody/platforms were high across antibodies (e.g., intraclass correlation coefficient [ICC] > 0.80 for CPS), except for SP142. Two levels of immunostaining intensities were observed: high (QR1 and SP263) and low (28–8, 22C3, and SP142). Reproducibilities across pathologists were higher for QR1 and SP263 (ICC ≥ 0.87 and ≥ 0.85 for TPS and CPS, respectively). QR1, SP263, and 28-8 showed the highest concordance with mRNA expression (ICC ≥ 0.81 for CPS). Accordingly, we proposed a standardized method for PD-L1 immunodetection and scoring, then tested it on 40 metastatic melanomas. This method included analysis of specimen quality (e.g., host-tumor interface and pigmentation). Concordances among antibodies were excellent for all criteria, and concordances among pathologists were better for the MELscore than for other scores.Conclusion: Harmonization of PD-L1 staining and scoring in melanomas with good concordance is achievable using the PD-L1 IHC protocols applied to other cancers; this reproducible approach can simplify daily practice. Our proposal for a PD-L1 standardized methodology has higher reproducibility across pathologists for clinical and research use.

Second-line pembrolizumab versus chemotherapy in Japanese patients with advanced esophageal cancer: subgroup analysis from KEYNOTE-181

Background Safe and effective treatments for advanced esophageal cancer are an unmet need in Japan. We report results of a subgroup analysis of Japanese patients enrolled in KEYNOTE-181, a randomized, open-label, phase 3 study of pembrolizumab versus chemotherapy as second-line therapy for patients with advanced or metastatic esophageal cancer whose disease progressed after standard first-line therapy. Methods Patients were randomly assigned 1:1 to receive pembrolizumab 200 mg every 3 weeks or investigator’s choice of paclitaxel, docetaxel, or irinotecan. Efficacy was evaluated in all Japanese patients and in those with programmed death ligand 1 combined positive score ≥ 10. Results Of the 152 Japanese patients enrolled (pembrolizumab, n = 77; chemotherapy, n = 75), 150 (98.7%) had squamous cell carcinoma and 79 (52.0%) had combined positive score ≥ 10. At the final analysis, median overall survival was improved among all patients (12.4 vs 8.2 months with pembrolizumab and chemotherapy, respectively; hazard ratio, 0.68; 95% CI 0.48–0.97) and patients with combined positive score ≥ 10 (12.6 vs 8.4 months; hazard ratio, 0.68; 95% CI 0.42–1.10). Fewer patients had any-grade (74.0% vs 95.9%) or grade 3–5 (16.9 vs 50.0%) treatment-related adverse events with pembrolizumab than with chemotherapy. Conclusion Consistent with the global trial results, second-line pembrolizumab therapy showed a survival benefit and a favorable safety profile compared with chemotherapy in Japanese patients with advanced esophageal cancer.

812 PROGRAMMED CELL DEATH PROTEIN 1/PROGRAMMED DEATH LIGAND 1 AND HLA-CLASS I ARE POTENTIAL THERAPEUTIC TARGETS IN ESOPHAGEAL NEUROENDOCRINE CARCINOMA

Esophageal neuroendocrine carcinoma (NEC) is a rare and aggressive subtype with a poor prognosis. Pembrolizumab was recommended for the treatment of PD-L1 positive tumors in esophageal cancer and the combined positive score (CPS) was reported to be a better predictor of efficacy compared to the tumor proportion score (TPS). We investigated the expression profile of potential therapeutic targets (PD-L1, HLA class I, Mismatch repair (MMR) proteins) and tumor infiltrating lymphocytes (TILs) in esophageal NEC. Methods 15 NECs of the esophagus including mixed neuroendocrine-non-neuroendocrine neoplasm (MiNEN) with squamous cell carcinoma (SCC) component were investigated in the study. The expression of PD-L1 (quantitatively evaluated by CPS and TPS), HLA class I, and MMR protein expression were examined immunohistochemically. TIL abundance was examined semiquantitatively by observation of H&E slides. Results Nine (60%) showed a CPS ≥ 1, five (33%) showed a CPS ≥10, and five cases showed a TPS ≥1. Survival analysis showed a significantly longer overall survival in the CPS ≥1 group than in the CPS &lt;1 group. Deficiency of MMR protein was not observed in any cases. HLA-Class I expression was retained in 10 (67%), and loss of HLA-Class I was significantly correlated with frequent lymph node metastasis, high TNM Stage, and low TIL. Three showed both PD-L1 CPS ≥ 10 and high TIL. Conclusion In esophageal NEC, PD-L1 positivity and preserved HLA-Class I expression were frequently observed, and PD-L1 CPS ≥ 1 was significantly associated with the better prognosis of esophageal NEC. Therefore, the PD-1/PD-L1 pathway and HLA-class I are thought to be potential therapeutic targets in esophageal neuroendocrine carcinoma.