Gemcitabine and cisplatin plus durvalumab with or without tremelimumab in chemotherapy-naive patients with advanced biliary tract cancer: an open-label, single-centre, phase 2 study.

BACKGROUND: Immunotherapies have shown clinical activity in patients with advanced biliary tract cancer, for which outcomes remain poor despite standard of care treatment with gemcitabine and cisplatin. We aimed to evaluate gemcitabine and cisplatin plus durvalumab with or without tremelimumab as first-line treatment in patients with advanced biliary tract cancer. METHODS: This open-label, single-centre, phase 2 study was conducted at Seoul National University Hospital. Eligible patients were treatment-naïve adults aged 18 years or older with histologically proven unresectable or recurrent biliary tract cancer, at least one measurable lesion based on the Response Evaluation Criteria in Solid Tumors (version 1.1), an Eastern Cooperative Oncology Group performance status of 0 or 1, life expectancy of 12 weeks or longer, and adequate healthy organ and bone marrow function. Initially, all patients received one 3-week cycle of gemcitabine (1000 mg/m2) and cisplatin (25 mg/m2) on day 1 and 8 followed by gemcitabine and cisplatin plus durvalumab (1120 mg) and tremelimumab (75 mg) on day 1 of each cycle, starting with the second cycle (chemotherapy followed by chemotherapy plus durvalumab and tremelimumab group). Following protocol amendment, patients were recruited to receive gemcitabine and cisplatin plus durvalumab, starting on day 1 of the first cycle (chemotherapy plus durvalumab group) or gemcitabine and cisplatin plus durvalumab and tremelimumab also from day 1 of the first cycle (chemotherapy plus durvalumab and tremelimumab group) in parallel and allocated using a random block method. Assessors and patients were not masked to the treatment group. The primary endpoint was objective response rate, assessed in the efficacy population (ie, patients who were treated at least until the first tumour response assessment). This study is registered with ClinicalTrials.gov, NCT03046862 (active). FINDINGS: Between March 2, 2017, and Feb 13, 2020, 128 patients were enrolled (32 in the chemotherapy followed by chemotherapy plus durvalumab and tremelimumab group, 49 in the chemotherapy plus durvalumab group, and 47 in the chemotherapy plus durvalumab and tremelimumab group). Four patients (two in the chemotherapy followed by chemotherapy plus durvalumab and tremelimumab group and two in the chemotherapy plus durvalumab group) were excluded and 124 were evaluable for tumour response. The median duration of follow-up was 48·2 months (IQR 41·5-49·4) for the chemotherapy followed by chemotherapy plus durvalumab and tremelimumab group, 26·6 months (19·0-27·9) for the chemotherapy plus durvalumab group, and 24·2 months (20·7-31·7) for the chemotherapy plus durvalumab and tremelimumab group. 82 (66%) of 124 patients achieved an objective response (15 [50%] of 30 in the chemotherapy followed by chemotherapy plus durvalumab and tremelimumab group, 34 [72%] of 47 in the chemotherapy plus durvalumab group, and 33 [70%] of 47 in the chemotherapy plus durvalumab and tremelimumab group). The most common grade 3 and 4 adverse events were decreased neutrophil count (67 [53%] of 126), anaemia (50 [40%]), and decreased platelet count (24 [19%]), with no unexpected safety events. No adverse events leading to discontinuation or death occurred. INTERPRETATION: Gemcitabine and cisplatin plus immunotherapy showed promising efficacy and acceptable safety in patients with biliary tract cancer. Gemcitabine and cisplatin plus durvalumab are being evaluated in the phase 3, TOPAZ-1 study (NCT03875235) as first-line treatment in patients with advanced biliary tract cancer. FUNDING: AstraZeneca; National Research Foundation of Korea (Grant No. 2021R1A2C2007430).

The Society for Immunotherapy of Cancer statement on best practices for multiplex immunohistochemistry (IHC) and immunofluorescence (IF) staining and validation.

OBJECTIVES: The interaction between the immune system and tumor cells is an important feature for the prognosis and treatment of cancer. Multiplex immunohistochemistry (mIHC) and multiplex immunofluorescence (mIF) analyses are emerging technologies that can be used to help quantify immune cell subsets, their functional state, and their spatial arrangement within the tumor microenvironment. METHODS: The Society for Immunotherapy of Cancer (SITC) convened a task force of pathologists and laboratory leaders from academic centers as well as experts from pharmaceutical and diagnostic companies to develop best practice guidelines for the optimization and validation of mIHC/mIF assays across platforms. RESULTS: Representative outputs and the advantages and disadvantages of mIHC/mIF approaches, such as multiplexed chromogenic IHC, multiplexed immunohistochemical consecutive staining on single slide, mIF (including multispectral approaches), tissue-based mass spectrometry, and digital spatial profiling are discussed. CONCLUSIONS: mIHC/mIF technologies are becoming standard tools for biomarker studies and are likely to enter routine clinical practice in the near future. Careful assay optimization and validation will help ensure outputs are robust and comparable across laboratories as well as potentially across mIHC/mIF platforms. Quantitative image analysis of mIHC/mIF output and data management considerations will be addressed in a complementary manuscript from this task force.

Optimal PD-L1-high cutoff for association with overall survival in patients with urothelial cancer treated with durvalumab monotherapy.

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.

Comparison of continuous measures across diagnostic PD-L1 assays in non-small cell lung cancer using automated image analysis.

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.

Safety and Efficacy of Durvalumab and Tremelimumab Alone or in Combination in Patients with Advanced Gastric and Gastroesophageal Junction Adenocarcinoma.

PURPOSE: This randomized, multicenter, open-label, phase Ib/II study assessed durvalumab and tremelimumab in combination or as monotherapy for chemotherapy-refractory gastric cancer or gastroesophageal junction (GEJ) cancer. PATIENTS AND METHODS: Second-line patients were randomized 2:2:1 to receive durvalumab plus tremelimumab (arm A), or durvalumab (arm B) or tremelimumab monotherapy (arm C), and third-line patients received durvalumab plus tremelimumab (arm D). A tumor-based IFNγ gene signature was prospectively evaluated as a potential predictive biomarker in second- and third-line patients receiving the combination (arm E). The coprimary endpoints were objective response rate and progression-free survival (PFS) rate at 6 months. RESULTS: A total of 113 patients were treated: 6 in phase Ib and 107 (arm A, 27; arm B, 24; arm C, 12; arm D, 25; arm E, 19) in phase II. Overall response rates were 7.4%, 0%, 8.3%, 4.0%, and 15.8% in the five arms, respectively. PFS rates at 6 months were 6.1%, 0%, 20%, 15%, and 0%, and 12-month overall survival rates were 37.0%, 4.6%, 22.9%, 38.8%, and NA, respectively. Treatment-related grade 3/4 adverse events were reported in 17%, 4%, 42%, 16%, and 11% of patients, respectively. CONCLUSIONS: Response rates were low regardless of monotherapy or combination strategies. No new safety signals were identified. Including use of a tumor-based IFNγ signature and change in baseline and on-treatment circulating tumor DNA are clinically feasible and may be novel strategies to improve treatment response in this difficult-to-treat population.

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

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.

Clinical Activity, Tolerability, and Long-Term Follow-Up of Durvalumab in Patients With Advanced NSCLC.

INTRODUCTION: Durvalumab is a selective, high-affinity human immunoglobulin G1 monoclonal antibody that blocks programmed cell death ligand 1 (PD-L1) binding to programmed death 1. Here we report safety and clinical activity in the NSCLC cohort of a phase I/II trial that included multiple tumor types (Study 1108; NCT01693562). METHODS: Patients with stage IIIB-IV NSCLC (squamous or nonsquamous) received durvalumab 10 mg/kg every 2 weeks for 12 months or until confirmed progressive disease or unacceptable toxicity. Primary objectives were safety and antitumor activity. Tumoral PD-L1 expression was assessed using the VENTANA SP263 Assay. Responses were assessed by blinded independent central review (Response Evaluation Criteria in Solid Tumors v1.1). Adverse events were graded according to National Cancer Institute's Common Terminology Criteria for Adverse Events (v4.03). RESULTS: Of 304 patients, 79.0% were previously treated. Confirmed objective response rate was 21.8% in patients with greater than or equal to 25% PD-L1 expression and 6.4% in those with less than 25%; 25.9% in first-line patients and 12.7% in previously treated patients; and 14.0% in squamous and 16.7% in nonsquamous disease. Median overall survival was 12.4 months and median progression-free survival was 1.7 months; both were numerically longer in the PD-L1 greater than or equal to 25% group than in the PD-L1 less than 25% group (overall survival 16.4 versus 7.6 months, respectively; progression-free survival 2.6 versus 1.4 months, respectively). Treatment-related adverse events occurred in 57.2%, were grade 3/4 in 10.2%, and led to discontinuation in 5.6%. One patient (0.3%) died of treatment-related pneumonia with underlying pneumonitis. CONCLUSIONS: Durvalumab was clinically active irrespective of histology in this mostly pretreated population, with a manageable safety profile. Response rates and survival appeared to be enhanced in patients with greater tumoral PD-L1 expression.

Automated image analysis of NSCLC biopsies to predict response to anti-PD-L1 therapy.

BACKGROUND: Immune checkpoint therapies (ICTs) targeting the programmed cell death-1 (PD1)/programmed cell death ligand-1 (PD-L1) pathway have improved outcomes for patients with non-small cell lung cancer (NSCLC), particularly those with high PD-L1 expression. However, the predictive value of manual PD-L1 scoring is imperfect and alternative measures are needed. We report an automated image analysis solution to determine the predictive and prognostic values of the product of PD-L1+ cell and CD8+ tumor infiltrating lymphocyte (TIL) densities (CD8xPD-L1 signature) in baseline tumor biopsies. METHODS: Archival or fresh tumor biopsies were analyzed for PD-L1 and CD8 expression by immunohistochemistry. Samples were collected from 163 patients in Study 1108/NCT01693562, a Phase 1/2 trial to evaluate durvalumab across multiple tumor types, including NSCLC, and a separate cohort of 199 non-ICT- patients. Digital images were automatically scored for PD-L1+ and CD8+ cell densities using customized algorithms applied with Developer XD™ 2.7 software. RESULTS: For patients who received durvalumab, median overall survival (OS) was 21.0 months for CD8xPD-L1 signature-positive patients and 7.8 months for signature-negative patients (p = 0.00002). The CD8xPD-L1 signature provided greater stratification of OS than high densities of CD8+ cells, high densities of PD-L1+ cells, or manually assessed tumor cell PD-L1 expression ≥25%. The CD8xPD-L1 signature did not stratify OS in non-ICT patients, although a high density of CD8+ cells was associated with higher median OS (high: 67 months; low: 39.5 months, p = 0.0009) in this group. CONCLUSIONS: An automated CD8xPD-L1 signature may help to identify NSCLC patients with improved response to durvalumab therapy. Our data also support the prognostic value of CD8+ TILS in NSCLC patients who do not receive ICT. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01693562 . Study code: CD-ON-MEDI4736-1108. Interventional study (ongoing but not currently recruiting). Actual study start date: August 29, 2012. Primary completion date: June 23, 2017 (final data collection date for primary outcome measure).

Safety and efficacy of durvalumab in patients with head and neck squamous cell carcinoma: results from a phase I/II expansion cohort.

INTRODUCTION: Durvalumab selectively blocks programmed cell death ligand-1 (PD-L1) binding to programmed cell death-1. Encouraging clinical activity and manageable safety were reported in urothelial carcinoma, non-small-cell lung cancer (NSCLC), hepatocellular carcinoma (HC) and small-cell lung cancer (SCLC) in a multicenter phase I/II study. Safety and clinical activity in recurrent/metastatic head and neck squamous cell carcinoma (HNSCC) were evaluated in the expansion phase. METHODS: Patients received 10 mg/kg of durvalumab intravenously every 2 weeks for 12 months or until confirmed progressive disease or unacceptable toxicity. The primary objective was safety; clinical activity was a secondary objective. RESULTS: Sixty-two patients were enrolled and evaluable (received first dose ≥24 weeks before data cutoff). Median age was 57 years; 40.3% were human papillomavirus (HPV)-positive; 32.3% had tumour cell PD-L1 expression ≥25%, and 62.9% were current/former smokers. They had a median of 2 prior systemic treatments (range, 1-13). All-causality adverse events (AEs) occurred in 98.4%; drug-related AEs occurred in 59.7% and were grade III-IV in 9.7%. There were no drug-related discontinuations or deaths. Objective response rate (blinded independent central review) was 6.5% (15.0% for PD-L1 ≥25%, 2.6% for <25%). Median time to response was 2.7 months (range, 1.2-5.5); median duration was 12.4 months (range, 3.5-20.5+). Median progression-free survival was 1.4 months; median overall survival (OS) was 8.4 months. OS rate was 62% at 6 months and 38% at 12 months (42% for PD-L1 ≥25%, 36% for <25%). CONCLUSIONS: Durvalumab safety in HNSCC was manageable and consistent with other cohorts of the study. Early, durable responses in these heavily pretreated patients warrant further investigation; phase III monotherapy and combination therapy studies are ongoing. CLINICAL TRIAL REGISTRY: clinicaltrials.gov NCT01693562; MedImmune study 1108.

Analytical Validation and Clinical Utility of an Immunohistochemical Programmed Death Ligand-1 Diagnostic Assay and Combined Tumor and Immune Cell Scoring Algorithm for Durvalumab in Urothelial Carcinoma.

CONTEXT.­: Clinical responses to anti-programmed death receptor-1 and anti-programmed death ligand-1 (PD-L1) agents are generally improved in patients with high PD-L1 expression compared with those with low/negative expression across several tumor types, including urothelial carcinoma. OBJECTIVE.­: To validate a PD-L1 immunohistochemical diagnostic test in urothelial carcinoma patients treated with the anti-PD-L1 monoclonal antibody durvalumab. DESIGN.­: The Ventana PD-L1 (SP263) assay was validated for intended use in urothelial carcinoma formalin-fixed, paraffin-embedded samples in studies addressing sensitivity, specificity, robustness, and precision, and implemented in study CD-ON-MEDI4736-1108 (NCT01693562). Efficacy was analyzed in patients classified according to prespecified PD-L1 expression cutoffs: PD-L1 high (if >1% of the tumor area contained tumor-associated immune cells, ≥25% of tumor cells or ≥25% of immune cells stained for PD-L1; if ≤1% of the tumor area contained immune cells, ≥25% of tumor cells or 100% of immune cells stained for PD-L1) and PD-L1 low/negative (did not meet criteria for PD-L1 high). RESULTS.­: The assay met all predefined acceptance criteria for sensitivity, specificity, and precision. Interreader and intrareader precision overall agreement were 93.0% and 92.4%, respectively. For intraday reproducibility and interday precision, overall agreement was 99.2% and 100%, respectively. Interlaboratory overall agreement was 92.6%. In study CD-ON-MEDI4736-1108, durvalumab demonstrated clinical activity and durable responses in both PD-L1-high and PD-L1-low/negative subgroups, although objective response rates tended to be higher in the PD-L1-high subgroup than in the PD-L1-low/negative subgroup. CONCLUSIONS.­: Determination of PD-L1 expression in urothelial carcinoma patients using the Ventana PD-L1 (SP263) assay was precise, highly reproducible, and clinically relevant.

Deep Semi Supervised Generative Learning for Automated Tumor Proportion Scoring on NSCLC Tissue Needle Biopsies.

The level of PD-L1 expression in immunohistochemistry (IHC) assays is a key biomarker for the identification of Non-Small-Cell-Lung-Cancer (NSCLC) patients that may respond to anti PD-1/PD-L1 treatments. The quantification of PD-L1 expression currently includes the visual estimation by a pathologist of the percentage (tumor proportional scoring or TPS) of tumor cells showing PD-L1 staining. Known challenges like differences in positivity estimation around clinically relevant cut-offs and sub-optimal quality of samples makes visual scoring tedious and subjective, yielding a scoring variability between pathologists. In this work, we propose a novel deep learning solution that enables the first automated and objective scoring of PD-L1 expression in late stage NSCLC needle biopsies. To account for the low amount of tissue available in biopsy images and to restrict the amount of manual annotations necessary for training, we explore the use of semi-supervised approaches against standard fully supervised methods. We consolidate the manual annotations used for training as well the visual TPS scores used for quantitative evaluation with multiple pathologists. Concordance measures computed on a set of slides unseen during training provide evidence that our automatic scoring method matches visual scoring on the considered dataset while ensuring repeatability and objectivity.

SLC46A3 as a Potential Predictive Biomarker for Antibody-Drug Conjugates Bearing Noncleavable Linked Maytansinoid and Pyrrolobenzodiazepine Warheads.

PURPOSE: Antibody-drug conjugates (ADC) utilizing noncleavable linker drugs have been approved for clinical use, and several are in development targeting solid and hematologic malignancies including multiple myeloma. Currently, there are no reliable biomarkers of activity for these ADCs other than presence of the targeted antigen. We observed that certain cell lines are innately resistant to such ADCs, and sought to uncover the underlying mechanism of resistance. EXPERIMENTAL DESIGN: The expression of 43 lysosomal membrane target genes was evaluated in cell lines resistant to ADCs bearing the noncleavable linker, pyrrolobenzodiazepine payload SG3376, in vitro. The functional relevance of SLC46A3, a lysosomal transporter of noncleavable ADC catabolites whose expression uniquely correlated with SG3376 resistance, was assessed using EPHA2-, HER2-, and BCMA-targeted ADCs and isogenic cells overexpressing or genetically inactivated for SLC46A3. SLC46A3 expression was also examined in patient-derived xenograft and in vitro models of acquired T-DM1 resistance and multiple myeloma bone marrow samples by RT-PCR. RESULTS: Loss of SLC46A3 expression was found to be a mechanism of innate and acquired resistance to ADCs bearing DM1 and SG3376. Sensitivity was restored in refractory lines upon introduction of SLC46A3, suggesting that expression of SLC46A3 may be more predictive of activity than target antigen levels alone. Interrogation of primary multiple myeloma samples indicated a range of SLC46A3 expression, including samples with undetectable levels like multiple myeloma cell lines resistant to BCMA-targeting DM1 and SG3376 ADCs. CONCLUSIONS: Our findings support SLC46A3 as a potential patient selection biomarker with immediate relevance to clinical trials involving these ADCs.

Consistency of tumor and immune cell programmed cell death ligand-1 expression within and between tumor blocks using the VENTANA SP263 assay.

BACKGROUND: Several anti-programmed cell death-1 (PD-1) and anti-programmed cell death ligand-1 (PD-L1) therapies have shown encouraging safety and clinical activity in a variety of tumor types. A potential role for PD-L1 testing in identifying patients that are more likely to respond to treatment is emerging. PD-L1 expression in clinical practice is determined by testing one tumor section per patient. Therefore, it is critical to understand the impact of tissue sampling variability on patients' PD-L1 classification. METHODS: Resected non-small cell lung cancer (NSCLC), head and neck squamous cell carcinoma (HNSCC) and urothelial carcinoma (UC) tissue samples (five samples per tumor type) were obtained from commercial sources and two tumor blocks were taken from each. Three sections from each block (~ 100 µm apart) were stained using the VENTANA PD-L1 (SP263) assay, and scored based on the percentage of PD-L1-staining tumor cells (TCs) or tumor-infiltrating immune cells (ICs) present. Each section was categorized as PD-L1 high or low/negative using a variety of cut-off values, and intra-block and intra-case (between blocks of the same tumor) concordance (overall percentage agreement [OPA]) were evaluated. An additional 200 commercial NSCLC samples were also analyzed, and intra-block concordance determined by scoring two sections per sample (≥70 µm apart). RESULTS: Concordance in TC PD-L1 classification was high at all applied cut-offs. Intra-block and intra-case OPA for the 15 NSCLC, HNSCC or UC samples were 100% and 80-100%, respectively, across all cut-offs; intra-block OPA for the 200 NSCLC samples was 91.0-98.5% across all cut-offs. IC PD-L1 classification was less consistent; intra-block and intra-case OPA for the 15 NSCLC, HNSCC or UC samples ranged between 70 and 100% and between 60 and 100%, respectively, with similar observations in the intra-block analysis of the 200 NSCLC samples. CONCLUSIONS: These results show the reproducibility of TC PD-L1 classification across the depth of the tumor using the VENTANA PD-L1 (SP263) assay. Practically, this means that treatment decisions based on TC PD-L1 classification can be made confidently, following analysis of one tumor section. Although more variable than TC staining, consistent IC PD-L1 classification was also observed within and between blocks and across cut-offs.

Tremelimumab combined with durvalumab in patients with mesothelioma (NIBIT-MESO-1): an open-label, non-randomised, phase 2 study.

BACKGROUND: Tremelimumab, an anti-CTLA4 monoclonal antibody, initially showed good activity when used alone in patients with mesothelioma, but did not improve the overall survival of patients who failed on first-line or second-line chemotherapy compared with placebo in the DETERMINE study. We aimed to investigate the efficacy and safety of first-line or second-line tremelimumab combined with durvalumab, an anti-PD-L1 monoclonal antibody, in patients with malignant mesothelioma. METHODS: In this open-label, non-randomised, phase 2 trial, patients with unresectable pleural or peritoneal mesothelioma received intravenous tremelimumab (1 mg/kg bodyweight) and durvalumab (20 mg/kg bodyweight) every 4 weeks for four doses, followed by maintenance intravenous durvalumab at the same dose and schedule for nine doses. The primary endpoint was the proportion of patients with an immune-related objective response according to the immune-related modified Response Evaluation Criteria in Solid Tumors (RECIST; for pleural mesothelioma) or immune-related RECIST version 1.1 (for peritoneal mesothelioma). The primary analysis was done by intention to treat, whereas the safety analysis included patients who received at least one dose of study drug. This trial is registered with the European Clinical Trials Database, number 2015-001995-23, and ClinicalTrials.gov, number NCT02588131, and is ongoing but no longer recruiting patients. FINDINGS: From Oct 30, 2015, to Oct 12, 2016, 40 patients with mesothelioma were enrolled and received at least one dose each of tremelimumab and durvalumab. Patients were followed-up for a median of 19·2 months (IQR 13·8-20·5). 11 (28%) of 40 patients had an immune-related objective response (all partial responses; confirmed in ten patients), with a median response duration of 16·1 months (IQR 11·5-20·5). 26 (65%) patients had immune-related disease control and 25 (63%) had disease control. Median immune-related progression-free survival was 8·0 months (95% CI 6·7-9·3), median progression-free survival was 5·7 months (1·7-9·7), and median overall survival was 16·6 months (13·1-20·1). Baseline tumour PD-L1 expression did not correlate with the proportion of patients who had an immune-related objective response or immune-related disease control, with immune-related progression-free survival, or with overall survival. 30 (75%) patients experienced treatment-related adverse events of any grade, of whom seven (18%) had grade 3-4 treatment-related adverse events. Treatment-related toxicity was generally manageable and reversible with protocol guidelines. INTERPRETATION: The combination of tremelimumab and durvalumab appeared active, with a good safety profile in patients with mesothelioma, warranting further exploration. FUNDING: Network Italiano per la Bioterapia dei Tumori Foundation, Associazione Italiana per la Ricerca sul Cancro, AstraZeneca, and Istituto Toscano Tumori.

Agreement between Programmed Cell Death Ligand-1 Diagnostic Assays across Multiple Protein Expression Cutoffs in Non-Small Cell Lung Cancer.

Purpose: Immunotherapies targeting programmed cell death-1 (PD-1) and programmed cell death ligand-1 (PD-L1) demonstrate encouraging antitumor activity and manageable tolerability in non-small cell lung cancer (NSCLC), especially in patients with high tumor PD-L1 expression, as detected by companion or complementary diagnostic assays developed for individual agents. A laboratory is unlikely to use multiple assay platforms. Furthermore, commercially available diagnostic assays are not standardized, and different assay methods could lead to inappropriate treatment selection. This study establishes the extent of concordance between three validated, commercially available PD-L1 IHC diagnostic assays for NSCLC patients [Ventana SP263 (durvalumab), Dako 22C3 (pembrolizumab), and Dako 28-8 (nivolumab)].Experimental Design: Five hundred formalin-fixed, paraffin-embedded archival NSCLC samples were obtained from commercial sources. Stained slides were read in batches on an assay-by-assay basis by a single pathologist trained in all methods, in a Clinical Laboratory Improvements Amendments program-certified laboratory. An additional pathologist performed an independent review of 200 stained samples for each assay.Results: PD-L1 expression was evaluable with all assays in 493 samples. The three assays showed similar patterns of tumor membrane staining, with high correlation between percent PD-L1 staining. An overall percentage agreement of >90% was achieved between assays at multiple expression cutoffs, including 1%, 10%, 25%, and 50% tumor membrane staining.Conclusions: This study builds optimism that harmonization between assays may be possible, and that the three assays studied could potentially be used interchangeably to identify patients most likely to respond to anti-PD-1/PD-L1 immunotherapies, provided the appropriate clinically defined algorithm and agent are always linked. Clin Cancer Res; 23(14); 3585-91. ©2017 AACR.

Development of a programmed cell death ligand-1 immunohistochemical assay validated for analysis of non-small cell lung cancer and head and neck squamous cell carcinoma.

BACKGROUND: A high-quality programmed cell-death ligand 1 (PD-L1) diagnostic assay may help predict which patients are more likely to respond to anti-programmed cell death-1 (PD-1)/PD-L1 antibody-based cancer therapy. Here we describe a PD-L1 immunohistochemical (IHC) staining protocol developed by Ventana Medical Systems Inc. and key analytical parameters of its use in formalin-fixed, paraffin-embedded (FFPE) samples of non-small cell lung cancer (NSCLC) and head and neck squamous cell carcinoma (HNSCC). METHODS: An anti-human PD-L1 rabbit monoclonal antibody (SP263) was optimized for use with the VENTANA OptiView DAB IHC Detection Kit on the automated VENTANA BenchMark ULTRA platform. The VENTANA PD-L1 (SP263) Assay was validated for use with FFPE NSCLC and HNSCC tissue samples in a series of studies addressing sensitivity, specificity, robustness, and precision. Samples from a subset of 181 patients from a Phase 1/2 study of durvalumab (NCT01693562) were analyzed to determine the optimal PD-L1 staining cut-off for enriching the probability of responses to treatment. The scoring algorithm was defined using statistical analysis of clinical response data from this clinical trial and PD-L1 staining parameters in HNSCC and NSCLC tissue. Inter-reader agreement was established by three pathologists who evaluated 81 NSCLC and 100 HNSCC samples across the range of PD-L1 expression levels. RESULTS: The VENTANA PD-L1 (SP263) Assay met all pre-defined acceptance criteria. For both cancer types, a cut-off of 25 % of tumor cells with PD-L1 membrane staining of any intensity best discriminated responders from nonresponders. Samples with staining above this value were deemed to have high PD-L1 expression, and those with staining below it were deemed to have low or no PD-L1 expression. Inter-reader agreement on PD-L1 status was 97 and 92 % for NSCLC and HNSCC, respectively. CONCLUSIONS: These results highlight the robustness and reproducibility of the VENTANA PD-L1 (SP263) Assay and support its suitability for use in the evaluation of NSCLC and HNSCC FFPE tumor samples using the devised ≥25 % tumor cell staining cut-off in a clinical setting. The clinical utility of the PD-L1 diagnostic assay as a predictive biomarker will be further validated in ongoing durvalumab studies. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01693562.

Safety and Efficacy of Durvalumab (MEDI4736), an Anti-Programmed Cell Death Ligand-1 Immune Checkpoint Inhibitor, in Patients With Advanced Urothelial Bladder Cancer.

PURPOSE: To investigate the safety and efficacy of durvalumab, a human monoclonal antibody that binds programmed cell death ligand-1 (PD-L1), and the role of PD-L1 expression on clinical response in patients with advanced urothelial bladder cancer (UBC). METHODS: A phase 1/2 multicenter, open-label study is being conducted in patients with inoperable or metastatic solid tumors. We report here the results from the UBC expansion cohort. Durvalumab (MEDI4736, 10 mg/kg every 2 weeks) was administered intravenously for up to 12 months. The primary end point was safety, and objective response rate (ORR, confirmed) was a key secondary end point. An exploratory analysis of pretreatment tumor biopsies led to defining PD-L1-positive as ≥ 25% of tumor cells or tumor-infiltrating immune cells expressing membrane PD-L1. RESULTS: A total of 61 patients (40 PD-L1-positive, 21 PD-L1-negative), 93.4% of whom received one or more prior therapies for advanced disease, were treated (median duration of follow-up, 4.3 months). The most common treatment-related adverse events (AEs) of any grade were fatigue (13.1%), diarrhea (9.8%), and decreased appetite (8.2%). Grade 3 treatment-related AEs occurred in three patients (4.9%); there were no treatment-related grade 4 or 5 AEs. One treatment-related AE (acute kidney injury) resulted in treatment discontinuation. The ORR was 31.0% (95% CI, 17.6 to 47.1) in 42 response-evaluable patients, 46.4% (95% CI, 27.5 to 66.1) in the PD-L1-positive subgroup, and 0% (95% CI, 0.0 to 23.2) in the PD-L1-negative subgroup. Responses are ongoing in 12 of 13 responding patients, with median duration of response not yet reached (range, 4.1+ to 49.3+ weeks). CONCLUSION: Durvalumab demonstrated a manageable safety profile and evidence of meaningful clinical activity in PD-L1-positive patients with UBC, many of whom were heavily pretreated.

A Biparatopic HER2-Targeting Antibody-Drug Conjugate Induces Tumor Regression in Primary Models Refractory to or Ineligible for HER2-Targeted Therapy.

Antibody-drug conjugate (ADC) which delivers cytotoxic drugs specifically into targeted cells through internalization and lysosomal trafficking has emerged as an effective cancer therapy. We show that a bivalent biparatopic antibody targeting two non-overlapping epitopes on HER2 can induce HER2 receptor clustering, which in turn promotes robust internalization, lysosomal trafficking, and degradation. When conjugated with a tubulysin-based microtubule inhibitor, the biparatopic ADC demonstrates superior anti-tumor activity over ado-trastuzumab emtansine (T-DM1) in tumor models representing various patient subpopulations, including T-DM1 eligible, T-DM1 ineligible, and T-DM1 relapsed/refractory. Our findings indicate that this biparatopic ADC has promising potential as an effective therapy for metastatic breast cancer and a broader patient population may benefit from this unique HER2-targeting ADC.