Sitravatinib combined with PD-1 blockade enhances cytotoxic T-cell infiltration by M2 to M1 tumor macrophage repolarization in esophageal adenocarcinoma.

Esophageal adenocarcinoma (EAC) is a leading cause of cancer-related mortality. Sitravatinib is a novel multi-gene tyrosine kinase inhibitor (TKI) that targets tumor-associated macrophage (TAM) receptors, VEGF, PDGF and c-Kit. Currently, sitravatinib is actively being studied in clinical trials across solid tumors and other TKIs have shown efficacy in combination with immune checkpoint inhibitors (ICI) in cancer models. In this study, we investigated the anti-tumor activity of sitravatinib alone and in combination with PD-1 blockade in an EAC rat model. Treatment response was evaluated by mortality, pre- and post-treatment MRI, gene expression, immunofluorescence and immunohistochemistry. Our results demonstrated adequate safety and significant tumor shrinkage in animals treated with sitravatinib, and more profoundly, sitravatinib and PD-1 inhibitor, AUNP-12 (P < 0.01). Suppression of TAM receptors resulted in increased gene expression of pro-inflammatory cytokines and decreased expression of anti-inflammatory cytokines, enhanced infiltration of CD8+ T cells, and M2 to M1 macrophage phenotype repolarization in the tumor microenvironment of treated animals (P < 0.01). Moreover, endpoint immunohistochemistry staining corroborated the anti-tumor activity by downregulation of Ki67 and upregulation of Caspase-3 in the treated animals. Additionally, pretreatment gene expression of TAM receptors and PD-L1 were significantly higher in major responders compared with the non-responders, in animals that received sitravatinib and AUNP-12 (P < 0.02), confirming that TAM suppression enhances the efficacy of PD-1 blockade. In conclusion, this study proposes a promising immunomodulatory strategy using a multi-gene TKI to overcome developed resistance to an ICI in EAC, establishing rationale for future clinical development.

Immune-related encephalitis after immune checkpoint inhibitor therapy.

BACKGROUND: Immune checkpoint inhibitors (ICI) have revolutionized cancer treatment but can trigger immune-related encephalitis. We report one of the largest case series of patients with immune-related encephalitis and review of the literature. METHODS: Retrospective series of patients with immune-related encephalitis and literature review. RESULTS: Fourteen patients with cancer treated with ICI (50% combination therapy) developed immune-related encephalitis. Diagnostic testing revealed cerebral spinal fluid (CSF) lymphocytic pleocytosis (85%) and elevated protein (69%), abnormal brain magnetic resonance imaging(MRI) (33%) or brain FDG-PET (25%), electroencephalogram (EEG) abnormalities (30%), and autoantibodies (31%). Encephalitis treatment included: corticosteroids (86%), intravenous immunoglobulin (IVIg) (36%), plasmapheresis (7%), and rituximab (29%). There were no deaths and 12 patients had significant recovery, although long-term complications were observed. All patients discontinued ICI. Longitudinal follow-up demonstrated anti-cancer response to ICI at 3 months (85%) and 6 months post-ICI initiation (77%). A literature review identified 132 patients with immune-related encephalitis. Most were treated with PD-1 inhibitors (18% combination). Common abnormalities included elevated CSF protein (84%) or pleocytosis (77%), abnormal brain MRI (65%), or autoantibodies (47%). Nearly all were treated with corticosteroids, many required additional therapy with IVIg (26%) or rituximab (12%). Most patients had clinical improvement (81%) but a minority (10%) had a clinical relapse after completing corticosteroid taper. ICIs were resumed in 7 patients (5%), with relapse in 3. CONCLUSIONS AND RELEVANCE: Immune-related encephalitis is treatable and improves with corticosteroids in most cases but may require additional immunosuppression. Re-emergence of encephalitis is rare and does not typically result in adverse outcomes, and this should be considered in neurological immune-related adverse event management guidelines.

Adjuvant Nivolumab in Resected Esophageal or Gastroesophageal Junction Cancer.

BACKGROUND: No adjuvant treatment has been established for patients who remain at high risk for recurrence after neoadjuvant chemoradiotherapy and surgery for esophageal or gastroesophageal junction cancer. METHODS: We conducted CheckMate 577, a global, randomized, double-blind, placebo-controlled phase 3 trial to evaluate a checkpoint inhibitor as adjuvant therapy in patients with esophageal or gastroesophageal junction cancer. Adults with resected (R0) stage II or III esophageal or gastroesophageal junction cancer who had received neoadjuvant chemoradiotherapy and had residual pathological disease were randomly assigned in a 2:1 ratio to receive nivolumab (at a dose of 240 mg every 2 weeks for 16 weeks, followed by nivolumab at a dose of 480 mg every 4 weeks) or matching placebo. The maximum duration of the trial intervention period was 1 year. The primary end point was disease-free survival. RESULTS: The median follow-up was 24.4 months. Among the 532 patients who received nivolumab, the median disease-free survival was 22.4 months (95% confidence interval [CI], 16.6 to 34.0), as compared with 11.0 months (95% CI, 8.3 to 14.3) among the 262 patients who received placebo (hazard ratio for disease recurrence or death, 0.69; 96.4% CI, 0.56 to 0.86; P<0.001). Disease-free survival favored nivolumab across multiple prespecified subgroups. Grade 3 or 4 adverse events that were considered by the investigators to be related to the active drug or placebo occurred in 71 of 532 patients (13%) in the nivolumab group and 15 of 260 patients (6%) in the placebo group. The trial regimen was discontinued because of adverse events related to the active drug or placebo in 9% of the patients in the nivolumab group and 3% of those in the placebo group. CONCLUSIONS: Among patients with resected esophageal or gastroesophageal junction cancer who had received neoadjuvant chemoradiotherapy, disease-free survival was significantly longer among those who received nivolumab adjuvant therapy than among those who received placebo. (Funded by Bristol Myers Squibb and Ono Pharmaceutical; CheckMate 577 ClinicalTrials.gov number, NCT02743494.).

Circulating Tumor DNA as a Predictive Biomarker for Clinical Outcomes With Margetuximab and Pembrolizumab in Pretreated HER2-Positive Gastric/ Gastroesophageal Adenocarcinoma.

PURPOSE: To assess the ability of circulating tumor DNA (ctDNA)-based testing to identify patients with HER2 (encoded by ERBB2)-positive gastric/gastroesophageal adenocarcinoma (GEA) who progressed on or after trastuzumab-containing treatments were treated with combination therapy of anti-HER2 and anti-PD-1 agents. METHODS: ctDNA analysis was performed retrospectively using plasma samples collected at study entry from 86 patients participating in the phase 1/2 CP-MGAH22-05 study (NCT02689284). RESULTS: Objective response rate (ORR) was significantly higher in evaluable ERBB2 amplification-positive vs - negative patients based on ctDNA analysis at study entry (37% vs 6%, respectively; P = .00094). ORR was 23% across all patients who were evaluable for response. ERBB2 amplification was detected at study entry in 57% of patients (all HER2 positive at diagnosis), and detection was higher (88%) when HER2 status was determined by immunohistochemistry fewer than 6 months before study entry. ctDNA was detected in 98% (84/86) of patients tested at study entry. Codetected ERBB2-activating mutations were not associated with response. CONCLUSIONS: Current ERBB2 status may be more effective than archival status at predicting clinical benefit from margetuximab plus pembrolizumab therapy. ctDNA testing for ERBB2 status prior to treatment will spare patients from repeat tissue biopsies, which may be reserved for reflex testing when ctDNA is not detected.

CSF-1R inhibitor, pexidartinib, sensitizes esophageal adenocarcinoma to PD-1 immune checkpoint blockade in a rat model.

Esophageal adenocarcinoma (EAC) is a leading cause of cancer deaths. Pexidartinib, a multi-gene tyrosine kinase inhibitor, through targeting colony-stimulating factor 1 (CSF-1) receptor (CSF-1R), down modulates macrophage-mediated pro-survival tumor signaling. Previously, CSF-1R inhibitors have successfully shown to enhance antitumor activity of PD-1/PD-L1 inhibitors by suppressing tumor immune evasion, in solid tumors. In this study, we investigated the antitumor activity of pexidartinib alone or in combination with blockade of PD-1 in a de novo EAC rat model. Here, we showed limited toxicity with significant tumor shrinkage in pexidartinib treated animals compared to controls, single agent and in combination with a PD-1 inhibitor, AUNP-12. Suppression of CSF-1/CSF-1R axis resulted in enhanced infiltration of CD3 + CD8 + T cells with reduced M2 macrophage polarization, in the tumor microenvironment (TME). Endpoint tissue gene expression in pexidartinib treated animals demonstrated upregulation of BAX, Cas3, TNFα, IFNγ and IL6 and downregulation of Ki67, IL13, IL10, TGFß and Arg1 (P < 0.05). Additionally, among the pexidartinib treated animals responders compared to nonresponders demonstrated a significant upregulation of pretreatment CSF-1 gene, confirming that tumor-associated macrophage suppression directly translates to clinical benefit. Moreover, a posttreatment serum cytokine assay exhibited similar systemic trends as the gene expression in the TME, depicting increases in proinflammatory cytokines and decreases in anti-inflammatory cytokines. In conclusion, our study established a promising combinatorial strategy using a CSF-1R inhibitor to overcome resistance to PD-1/PD-L1 axis blockade in an EAC model, providing the rationale for future clinical strategies.

A blood-based circulating microbial metagenomic panel for early diagnosis and prognosis of oesophageal adenocarcinoma.

BACKGROUND: Emerging evidence indicates the potential clinical significance of specific microbial signatures as diagnostic and prognostic biomarkers, in multiple cancers. However, to date, no studies have systematically interrogated circulating metagenome profiling in oesophageal adenocarcinoma (EAC) patients, particularly as novel non-invasive, early detection, surveillance and prognostic classifiers. METHODS: Metagenome sequencing was performed on 81 serum specimens collected across EAC spectrum, with sequencing reads classified using Bracken and MetaPhlAn3. Followed by the Linear Discriminant Analysis effect size (LEfSe) method to identify microbial profiles between groups. Logistic regression and Kaplan-Meier analyses were used to build classifiers. RESULTS: A significant loss of alpha and beta diversity was identified in serum specimens from EAC patients. We observed a shift in microbial taxa between each group-at the phylum, genus, and species level-with Lactobacillus sakei as the most prominent species in gastroesophageal reflux (GERD) vs other patient groups. Interestingly, LEfSe analysis identified a complete loss of Lactobacillus (L. Sakei and L. Curvatus), Collinsella stercoris and Bacteroides stercoris but conversely a significant increase in Escherichia coli in patients with EAC. Finally, we developed a metagenome panel that discriminated EAC from GERD patients with an AUC value of 0.89 (95% CI: 0.78-0.95; P < 0.001) and this panel in conjunction with the TNM stage was a robust predictor of overall survival (≥24 months; AUC = 0.84 (95% CI: 0.66-0.92; P = 0.006)). CONCLUSION: This study firstly describes unique blood-based microbial profiles in patients across EAC carcinogenesis, that are further utilised to establish a novel circulating diagnostic and prognostic metagenomic signature for EAC. TRANSLATIONAL RELEVANCE: Accumulating data indicates the clinical relevance of specific microbial signatures as diagnostic and prognostic biomarkers, in multiple cancers. However, to date, no studies have systematically interrogated circulating metagenome profiling in patients with oesophageal adenocarcinoma (EAC). Herein, we performed metagenome sequencing in serum specimens from EAC patients 81 collected across EAC spectrum and observed a significant loss of alpha and beta diversity, with a shift in microbial taxa between each group-at the phylum, genus, and species level-with Lactobacillus sakei as the most prominent species in gastroesophageal reflux (GERD) vs other patient groups. Interestingly, LEfSe analysis identified a complete loss of Lactobacillus (L. Sakei and L. Curvatus), Collinsella stercoris and Bacteroides stercoris but conversely a significant increase in Escherichia coli in patients with EAC. Finally, we developed a metagenome panel that discriminated EAC from GERD patients with an AUC value of 0.89 and this panel, in conjunction with the TNM stage, was a robust predictor of overall survival. This study for the first time describes unique blood-based microbial profiles in patients across EAC carcinogenesis, that are further utilised to establish a novel circulating diagnostic and prognostic metagenomic signature for EAC.

Targeting the Hedgehog Pathway Using Itraconazole to Prevent Progression of Barrett's Esophagus to Invasive Esophageal Adenocarcinoma.

OBJECTIVE: The aim of the study was to investigate whether inhibition of Sonic Hedgehog (SHH) pathway would prevent progression of Barrett's Esophagus (BE) to esophageal adenocarcinoma. BACKGROUND: The hedgehog signaling pathway is a leading candidate as a molecular mediator of BE and esophageal adenocarcinoma (EAC). Repurposed use of existing off-patent, safe and tolerable drugs that can inhibit hedgehog, such as itraconazole, could prevent progression of BE to EAC. METHODS: The efficacy of itraconazole was investigated using a surgical rat reflux model of Barrett's Metaplasia (BM). Weekly intraperitoneal injections of saline (control group) or itraconazole (treatment group; 200 mg/kg) were started at 24 weeks postsurgery. Esophageal tissue was harvested at 40 weeks. The role of the Hh pathway was also evaluated clinically. Esophageal tissue was harvested after 40 weeks for pathological examination and evaluation of the SHH pathway by immunohistochemistry. RESULTS: BM was present in control animals 29 of 31 (93%) versus itraconazole 22 of 24 (91%). EAC was significantly lower in itraconazole 2 of 24 (8%) versus control 10 of 31 (32%), respectively (P = 0.033). Esophageal SHH levels were lower in itraconazole vs control (P = 0.12). In esophageal tissue from humans with recurrent or persistent dysplastic BE within 24 months of ablative treatment, strong SHH and Indian Hedgehog expression occurred in distal BE versus proximal squamous epithelium, odds ratio = 6.1 (95% confidence interval: 1.6, 23.4) and odds ratio = 6.4 (95% confidence interval: 1.2, 32.8), respectively. CONCLUSION: Itraconazole significantly decreases EAC development and SHH expression in a preclinical animal model of BM. In humans, BE tissue expresses higher SHH, Indian Hedgehog, and bone morphogenic protein levels than normal squamous esophageal epithelium.

Healthcare utilization and total costs of care among patients with advanced metastatic gastric and esophageal cancer.

Aim: Study first-line (1L) treatment patterns and economic outcomes among patients with advanced metastatic gastric cancer (GC) and esophageal cancer (EC). Materials & methods: Newly diagnosed patients with systemic GC and EC treatments were identified between 1 January 2011 and 31 July 2017; costs were presented as per patient per month (PPPM) basis. Results: Study included 392 GC and 436 EC patients. Most frequently used 1L regimens were: 5-fluorouracil (5-FU) + oxaliplatin (22.5%) and epirubicin + cisplatin + 5-FU (ECF)/ECF modifications (21.9%) in patients with GC; and carboplatin + paclitaxel (29.6%) and 5-FU + oxaliplatin (11.5%) in EC patients. Mean all-cause costs were US$16,242 PPPM for GC, and $18,384 PPPM for EC during 1L treatment. Conclusion: GC and EC were resource intensive and costly. High costs and short treatment durations underscored a gap in care in 1L treatment.

Margetuximab plus pembrolizumab in patients with previously treated, HER2-positive gastro-oesophageal adenocarcinoma (CP-MGAH22-05): a single-arm, phase 1b-2 trial.

BACKGROUND: Margetuximab, a novel, investigational, Fc-engineered, anti-HER2 monoclonal antibody, is designed to more effectively potentiate innate immunity than trastuzumab. We aimed to evaluate the safety, tolerability, and antitumour activity of margetuximab plus pembrolizumab (an anti-PD-1 monoclonal antibody) in previously treated patients with HER2-positive gastro-oesophageal adenocarcinoma. METHODS: CP-MGAH22-05 was a single-arm, open-label, phase 1b-2 dose-escalation and cohort expansion study done at 11 academic centres in the USA and Canada and 15 centres in southeast Asia (Korea, Taiwan, and Singapore) that enrolled men and women aged 18 years or older with histologically proven, unresectable, locally advanced or metastatic, HER2-positive, PD-L1-unselected gastro-oesophageal adenocarcinoma, with an Eastern Cooperative Oncology Group performance status of 0 or 1, who had progressed after at least one previous line of therapy with trastuzumab plus chemotherapy in the locally advanced unresectable or metastatic setting. In the dose-escalation phase, nine patients were treated: three received margetuximab 10 mg/kg intravenously plus pembrolizumab 200 mg intravenously every 3 weeks and six received the recommended phase 2 dose of margetuximab 15 mg/kg plus pembrolizumab 200 mg intravenously every 3 weeks. An additional 86 patients were enrolled in the phase 2 cohort expansion and received the recommended phase 2 dose. The primary endpoints were safety and tolerability, assessed in the safety population (patients who received at least one dose of either margetuximab or pembrolizumab) and the objective response rate as assessed by the investigator according to both Response Evaluation Criteria in Solid Tumors (RECIST), version 1.1, in the response-evaluable population (patients with measurable disease at baseline and who received the recommended phase 2 dose of margetuximab and pembrolizumab). This trial is registered with ClinicalTrials.gov, NCT02689284. Recruitment for the trial has completed and follow-up is ongoing. FINDINGS: Between Feb 11, 2016, and Oct 2, 2018, 95 patients were enrolled. Median follow-up was 19·9 months (IQR 10·7-23·1). The combination therapy showed acceptable safety and tolerability; there were no dose-limiting toxicities in the dose-escalation phase. The most common grade 3-4 treatment-related adverse events were anaemia (four [4%]) and infusion-related reactions (three [3%]). Serious treatment-related adverse events were reported in nine (9%) patients. No treatment-related deaths were reported. Objective responses were observed in 17 (18·48%; 95% CI 11·15-27·93) of 92 evaluable patients. INTERPRETATION: These findings serve as proof of concept of synergistic antitumour activity with the combination of an Fc-optimised anti-HER2 agent (margetuximab) along with anti-PD-1 checkpoint blockade (pembrolizumab). FUNDING: MacroGenics.

The emerging role of immunotherapy for esophageal cancer.

PURPOSE OF REVIEW: The management of esophageal cancer has not changed significantly over the last decade. Survival rates remain poor in locally advanced and metastatic disease. Newer treatment modalities are desperately needed if we are to improve 5-year overall survival rates. Immunotherapeutic strategies hold great promise, but a much greater understanding of the immune microenvironment underlying squamous cell and esophageal adenocarcinoma is needed if we are to exploit the inherent cancer fighting capabilities of each patient's immune system. RECENT FINDINGS: Here we describe current and future predictive biomarkers, provide a synopsis of the most significant trial results to date, and explain pivotal ongoing phase III trials. SUMMARY: Recent findings suggest that esophageal squamous cell carcinoma may be more sensitive to single agent PD-1 inhibition than esophageal adenocarcinoma, and selecting patients according to PD-L1 combined positive score (CPS) of at least 10 or more may predict higher response rate. We await data indicating the optimal immuno-oncology (IO-IO) combinations that will allow more patients to respond, however it is likely that personalized immunotherapy may be required for the majority. At the present time, it is hoped that chemotherapy combined with PD-1 inhibition will be an optimal strategy, but we await confirmation from soon-to-be published phase III trials.

Emerging Multimodality Approaches to Treat Localized Esophageal Cancer.

Esophageal cancer has a poor prognosis, with 5-year survival rates ranging from 20% to 35% in the nonmetastatic setting. Despite advances in surgical techniques and optimization of chemoradiotherapy regimens, overall survival benefits have been incremental at best. Esophageal cancer requires a concerted multidisciplinary approach, perhaps more so than any other tumor type given the integral role played by the esophagus in maintaining calorific intake and the propensity for early spread through the lymphatics. This review describes the latest in surgical techniques to minimize postoperative complications and examines previous and ongoing systemic therapy approaches. Strategies that harness a patient's own immune system hold great promise, and shifting checkpoint inhibitors from the metastatic setting to the neoadjuvant/adjuvant setting is currently being evaluated in phase II and III clinical trials. In addition, a much better understanding of the interplay between tumors and their immune microenvironment is clearly needed to better judge how best to engage each patient's immune system, and there will be likely demonstrable differences between early-stage tumors and metastatic disease. This review highlights emerging data, which demonstrate that, in addition to The Cancer Genome Atlas classification of esophageal squamous cell carcinoma having a distinct molecular makeup compared with esophageal adenocarcinoma, there are also differing responses to PD-1 inhibitors. Histology and the underlying immune milieu may have important ramifications for the management of localized disease in the future, above and beyond PD-L1 expression, microsatellite instability status, and tumor mutational burden.

The Dynamic and Transient Immune Microenvironment in Locally Advanced Esophageal Adenocarcinoma Post Chemoradiation.

OBJECTIVE: The aim of this study was to assess the impact of chemoradiation on the immune microenvironment to influence and optimally design future neoadjuvant clinical trials. SUMMARY BACKGROUND DATA: Programmed death (PD)-1 inhibitors in metastatic gastroesophageal cancer have demonstrated response rates of approximately 25% in programmed death ligand-1 (PD-L1+) tumors. Unfortunately, the majority of patients do not respond. Therefore, a rationale strategy of combining immunotherapeutic agents with chemoradiation in earlier stage esophageal cancer may prevent metastatic disease in patients. METHODS: To determine the effects of chemoradiation on resected esophageal adenocarcinomas, we examined the immune microenvironment pre- and post-chemoradiation using immunohistochemistry, quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), and functional analysis of tumor-infiltrating lymphocytes. Additionally, to assess the duration and dependency of radiation-induced PD-L1 upregulation, a surgical rat reflux model of esophageal adenocarcinoma is used. First, tumor-bearing animals were dosed with single-fraction 13Gy or 16Gy radiation to determine safety, dose correlation, and PD-L1 upregulation using qRT-PCR post-radiation. Next, longitudinal PD-L1 expression levels within individual animals were determined using serial endoscopic biopsies at baseline, 1, 5, and 9 weeks post 16Gy radiation. RESULTS: The majority of cancers displayed enhanced interferon γ and activated CD8+ T lymphocytes at the tumor stroma interface. These tumors also demonstrated enhanced upregulation of PD-L1 and multiple other immune checkpoints including TIM3, GITR, IDO1, LAG3, OX40, and KIR. The animal model results indicated PD-L1 upregulation is dose-dependent and transiently elevated post radiation exposure. CONCLUSIONS: Collectively, these findings provide insights into the evolving immune landscape after chemoradiation and have significant implications for neoadjuvant trial designs that will combine radiotherapy with immune checkpoint inhibitors.

A Randomized Phase II Study of Metformin plus Paclitaxel/Carboplatin/Bevacizumab in Patients with Chemotherapy-Naïve Advanced or Metastatic Nonsquamous Non-Small Cell Lung Cancer.

BACKGROUND: In the absence of a targeted oncogenic driver mutation or high programmed death-ligand 1 expression, systemic therapy with platinum-based doublet chemotherapy with or without bevacizumab has been the standard treatment in advanced or metastatic non-small cell lung cancer (NSCLC). Metformin has been shown to have antitumor effects via a variety of insulin-dependent and insulin-independent mechanisms and to be potentially synergistic with chemotherapy. MATERIALS AND METHODS: This open-label single-center phase II study (NCT01578551) enrolled patients with chemotherapy-naïve advanced or metastatic nonsquamous NSCLC and randomized them (3:1) to receive carboplatin, paclitaxel, and bevacizumab with (Arm A) or without (Arm B) concurrent metformin for four to six cycles followed by maintenance therapy with bevacizumab ± metformin continued until disease progression, intolerable toxicity, or study withdrawal. The primary outcome was 1-year progression free survival (PFS). Secondary outcomes included overall survival, response to therapy, and toxicity. RESULTS: A total of 25 patients were enrolled from August 2012 to April 2015, of whom 24 received at least one cycle of therapy administration. The study was stopped early due to slow accrual and changes in standard first-line therapy of advanced NSCLC. The 1-year PFS on Arm A (n = 18) was 47% (95% confidence interval [CI]: 25%-88%), which exceeded the historical control 1-year PFS of 15%. Median overall survival of patients treated on Arm A was 15.9 months (95% CI: 8.4-not available [NA]) and 13.9 months (95% CI: 12.7-NA) on Arm B. There were no significant differences in toxicity between the study arms. CONCLUSION: To the authors' knowledge, this is the first study to show a significant benefit in PFS with the use of metformin in this patient population and is a signal of efficacy for metformin in advanced NSCLC. IMPLICATIONS FOR PRACTICE: The anticancer effects of metformin continue to be elucidated. To the authors' knowledge, this is the first trial in nondiabetic advanced non-small cell lung cancer patients to show a significant change in outcome with the addition of metformin to standard first-line chemotherapy. Well tolerated and widely available, metformin is a drug that should be considered for further study in the lung cancer treatment landscape.

Serial Endoscopic Evaluation of Esophageal Disease in a Cancer Model: A Paradigm Shift for Esophageal Adenocarcinoma (EAC) Drug Discovery and Development.

A rat model of surgically induced reflux recapitulates the development and progression of human esophageal adenocarcinoma (EAC). In this study, reflux was induced in rats followed by postoperative endoscopy with biopsy, to diagnose and monitor disease progression. Overall, percentage agreement between visual endoscopy and gold standard histology was 95%, with disease-specific classification accuracies of 100% and 75% for Barrett's with dysplasia and EAC, respectively. Additionally, the percentage agreement for biopsy in tumors >4 mm was 75%. Thereby, establishing endoscopic evaluation as a reliable tool to assess disease progression and provide biopsies for downstream correlates in a de novo EAC model.

Patterns of PD-L1 expression and CD8 T cell infiltration in gastric adenocarcinomas and associated immune stroma.

OBJECTIVE: Recent data supports a significant role for immune checkpoint inhibitors in the treatment of solid tumours. Here, we evaluate gastric and gastro-oesophageal junction (G/GEJ) adenocarcinomas for their expression of programmed death-ligand 1 (PD-L1), infiltration by CD8+ T cells and the relationship of both factors to patient survival. DESIGN: Thirty-four resections of primary invasive G/GEJ were stained by immunohistochemistry for PD-L1 and CD8 and by DNA in situ hybridisation for Epstein-Barr virus (EBV). CD8+ T cell densities both within tumours and at the tumour-stromal interface were analysed using whole slide digital imaging. Patient survival was evaluated according to PD-L1 status and CD8 density. RESULTS: 12% of resections showed tumour cell membranous PD-L1 expression and 44% showed expression within the immune stroma. Two cases (6%) were EBV positive, with one showing membranous PD-L1 positivity. Increasing CD8+ densities both within tumours and immune stroma was associated with increasing percentage of tumour (p=0.027) and stromal (p=0.005) PD-L1 expression. Both tumour and immune stromal PD-L1 expression and high intratumoral or stromal CD8+ T cell density (>500/mm2) were associated with worse progression-free survival (PFS) and overall survival (OS). CONCLUSIONS: PD-L1 is expressed on both tumour cells and in the immune stroma across all stages and histologies of G/GEJ. Surprisingly, we demonstrate that increasing CD8 infiltration is correlated with impaired PFS and OS. Patients with higher CD8+ T cell densities also have higher PD-L1 expression, indicating an adaptive immune resistance mechanism may be occurring. Further characterisation of the G/GEJ immune microenvironment may highlight targets for immune-based therapy.

PI3K/mTOR Dual Inhibitor, LY3023414, Demonstrates Potent Antitumor Efficacy Against Esophageal Adenocarcinoma in a Rat Model.

OBJECTIVE: The purpose of the current study is to determine the efficacy of a PI3K/mTOR dual inhibitor, LY3023414, on established EAC in an in vivo model. BACKGROUND: Esophageal adenocarcinoma (EAC) is a highly lethal cancer with limited treatment options. The PI3K/mTOR pathway is upregulated in EAC and may be a target for novel therapies. METHODS: Esophagojejunostomy was performed on Sprague-Dawley rats to induce carcinogenesis, and LY3023414 was cyclically administered intraperitoneally between 32 and 40 weeks postsurgery to treatment animals. Magnetic resonance imaging (MRI) and histology were used to determine clinical response. Immunohistochemistry, immunofluorescence, and Western blot were used to validate apoptosis by cleaved caspase-3, proliferation by Ki67, and pathway inhibition, respectively. RESULTS: Mean MRI tumor volume increased by 109.2% in controls (n = 32) and decreased by 56.8% in treatment animals (n=17) (P < 0.01). Treatment with LY3023414 demonstrated tumor volume increase in 0% (control = 46.4%) (P < 0.01), decrease in 58.8% (control = 7.1%) (P < 0.01), and stable volume in 41.2% (control = 46.4%) (P = 0.77). EAC prevalence in controls increased by 25%; whereas, prevalence in treatment animals decreased by 29.4% (P < 0.01). Approximately, 75% of treatment animals presenting with residual masses on MRI had a histological response >50%. Increased apoptosis by cleaved caspase-3 (P = 0.03) and decreased proliferation by Ki67 (P < 0.01) were demonstrated in the treatment arm, when compared with the control arm. On Western blot analysis of pathway checkpoints, p-mTOR (p=0.03) and PI3K-α (P = 0.04) were downregulated in treatment responsive residual tumors, when compared with controls. CONCLUSIONS: LY3023414 demonstrates efficacy against EAC in a preclinical model, establishing the rationale for clinical testing.

Dabrafenib in patients with BRAF(V600E)-positive advanced non-small-cell lung cancer: a single-arm, multicentre, open-label, phase 2 trial.

BACKGROUND: Activating BRAF(V600E) (Val600Glu) mutations are found in about 1-2% of lung adenocarcinomas, which might provide an opportunity for targeted treatment in these patients. Dabrafenib is an oral selective inhibitor of BRAF kinase. We did a trial to assess the clinical activity of dabrafenib in patients with advanced non-small-cell lung cancer (NSCLC) positive for the BRAF(V600E) mutation. METHODS: In this phase 2, multicentre, non-randomised, open-label study, we enrolled previously treated and untreated patients with stage IV metastatic BRAF(V600E)-positive NSCLC. Patients received oral dabrafenib 150 mg twice daily. The primary endpoint was investigator-assessed overall response, which was assessed in patients who had received at least one dose of dabrafenib; safety was also assessed in this population. The study is ongoing but not enrolling patients in this cohort. This trial is registered with ClinicalTrials.gov, number NCT01336634. FINDINGS: Between Aug 3, 2011, and Feb 25, 2014, 84 patients were enrolled, six of whom had not previously received systemic treatment for NSCLC. 26 of the 78 previously treated patients achieved an investigator-assessed overall response (33% [95% CI 23-45]). Four of the six previously untreated patients had an objective response. One patient died from an intracranial haemorrhage that was judged by the investigator to be due to the study drug. Serious adverse events were reported in 35 (42%) of 84 patients. The most frequent grade 3 or worse adverse events were cutaneous squamous-cell carcinoma in ten (12%), asthenia in four (5%), and basal-cell carcinoma in four (5%). INTERPRETATION: Dabrafenib showed clinical activity in BRAF(V600E)-positive NSCLC. Our findings suggest that dabrafenib could represent a treatment option for a population of patients with limited therapeutic options. FUNDING: GlaxoSmithKline.

Immunotherapy in upper GI malignancies.

OPINION STATEMENT: A comprehensive analysis of the interactions that can occur amongst three complex systems-the tumor cell, tissue microenvironment, and the immune response, is required if we are to realize the potential of immunotherapeutics in gastroesophageal cancer. For many years, epithelial cancers were believed to originate due to the transformation of tissue stem cells. Recently however, it has suggested that bone marrow-derived cells (BMDCs), which are frequently recruited to sites of tissue injury and inflammation, might also represent a potential source of malignancy. The link between infection, chronic inflammation, and cancer has long been recognized in gastric cancer with its close association with Helicobacter pylori as a class I carcinogen. The long-term consequences of recruiting pluripotent cells to areas of chronic inflammation which can result in altered cell signaling and differentiation needs to be defined, but this work provides a fascinating insight into the pivotal role played by the immune system in the development of upper GI tumors. Here, we discuss many of the immunotherapeutic strategies that have been assessed in gastroesophageal cancer in the last two decades. At the time of writing, the use of checkpoint inhibitors represents the most exciting approach and displays the greatest potential for widespread adoption in the clinic. Preliminary data suggest that programmed death ligand-1 (PD-L1) expression ranges from approximately 18 to 42% in gastroesophageal cancer. Phase II and phase III clinical trials involving either single agent PD-1/PD-L1 inhibition or combined with CTLA-4 inhibitors are currently enrolling, and it is expected that checkpoint inhibition will become a new standard of care in the management of advanced disease in the near future.

Delivering maximum clinical benefit at an affordable price: engaging stakeholders in cancer care.

Cancer costs continue to increase alarmingly despite much debate about how they can be reduced. The oncology community needs to take greater responsibility for our own practice patterns, especially when using expensive tests and treatments with marginal value: we cannot continue to accept novel therapeutics with very small benefits for exorbitant prices. Patients, payers, and pharmaceutical communities should be constructively engaged to communicate medically and economically possible goals, and eventually, to reduce use and costs. Diagnostic tests and treatments should have to show true value to be added to existing protocols. In this article, we discuss three key drivers of costs: end-of-life care patterns, medical imaging, and drugs. We propose health-care models that have the potential to decrease costs and discuss solutions to maintain clinical benefit at an affordable price.

Cixutumumab for patients with recurrent or refractory advanced thymic epithelial tumours: a multicentre, open-label, phase 2 trial.

BACKGROUND: No standard treatment exists for refractory or relapsed advanced thymic epithelial tumours. We investigated the efficacy of cixutumumab, a fully human IgG1 monoclonal antibody targeting the insulin-like growth factor 1 receptor in thymic epithelial tumours after failure of previous chemotherapy. METHODS: Between Aug 25, 2009, and March 27, 2012, we did a multicentre, open-label, phase 2 trial in patients aged 18 years or older with histologically confirmed recurrent or refractory thymic epithelial tumours. We enrolled individuals who had progressed after at least one previous regimen of platinum-containing chemotherapy, had an Eastern Cooperative Oncology Group performance status of 0 or 1, and had measurable disease and adequate organ function. Eligible patients received intravenous cixutumumab (20 mg/kg) every 3 weeks until disease progression or development of intolerable toxic effects. The primary endpoint was the frequency of response, analysed on an intention-to-treat basis. We also did pharmacodynamic studies. This trial is registered with ClinicalTrials.gov, number NCT00965250. FINDINGS: 49 patients were enrolled (37 with thymomas and 12 with thymic carcinomas) who received a median of eight cycles of cixutumumab (range 1-46). At the final actuarial analysis when follow-up data were updated (Nov 30, 2012), median potential follow-up (from on-study date to most current follow-up date) was 24·0 months (IQR 17·3-36·9). In the thymoma cohort, five (14%) of 37 patients (95% CI 5-29) achieved a partial response, 28 had stable disease, and four had progressive disease. In the thymic carcinoma cohort, none of 12 patients (95% CI 0-26) had a partial response, five had stable disease, and seven had progressive disease. The most common grade 3-4 adverse events in both cohorts combined were hyperglycaemia (five [10%]), lipase elevation (three [6%]), and weight loss, tumour pain, and hyperuricaemia (two each [4%]). Nine (24%) of 37 patients with thymoma developed autoimmune conditions during treatment (five were new-onset disorders), the most common of which was pure red-cell aplasia. Two (4%) patients died; one was attributed to disease progression and the other to disease-related complications (respiratory failure, myositis, and an acute coronary event), which could have been precipitated by treatment with cixutumumab. INTERPRETATION: Cixutumumab monotherapy is well-tolerated and active in relapsed thymoma. Development of autoimmunity during treatment needs further investigation. FUNDING: Division of Cancer Treatment and Diagnosis at the National Cancer Institute (National Institutes of Health), ImClone Systems.