Unraveling Emerging Anal Cancer Clinical Biomarkers from Current Immuno-Oncogenomics Advances

Anal squamous cell carcinoma (ASCC) is a rare gastrointestinal malignancy associated with high-risk human papillomavirus (HPV) and is currently one of the fastest-growing causes of cancer incidence and mortality in developed countries. Although next-generation sequencing technologies (NGS) have revolutionized cancer and immuno-genomic research in various tumor types, a limited amount of clinical research has been developed to investigate the expression and the functional characterization of genomic data in ASCC. Herein, we comprehensively assess recent advancements in "omics" research, including a systematic analysis of genome-based studies, aiming to identify the most relevant ASCC cancer driver gene expressions and their associated signaling pathways. We also highlight the most significant biomarkers associated with anal cancer progression, gene expression of potential diagnostic biomarkers, expression of therapeutic drug targets, and emerging treatment opportunities. This review stresses the urgent need for developing target-specific therapies in ASCC. By illuminating the molecular characteristics and drug-target expression in ASCC, this study aims to provide insights for the development of precision medicine in anal cancer.

Management of unexpected laboratory exposure to Burkholderia pseudomallei

Burkholderia pseudomallei is a Gram-negative saprophytic bacillus that causes melioidosis. The infection is endemic in South-East of Asia and Northern Australia. B. pseudomallei has been designated as bioterrorism agent and its manipulation should be done in a biological safety level 3 capability. Workers in laboratories may be accidentally exposed to B. pseudomallei before its identification, with a risk of laboratory-acquired melioidosis. We want to describe a case of melioidosis occurred in our hospital and its management at laboratory. The objective of this article is to provide guidance to microbiologists confronted with a suspicious case of B. pseudomallei on the management of the exposition. We report here a couple of microbiological arguments that can usually guide microbiologists towards presumptive identification of B. pseudomallei. This case report shows the importance of MALDI-TOF MS accurate databases to ensure accurate microbial identification and antibiotic prophylaxis adapted to individuals who were exposed. We also want to underline the importance of developing an effective strategy of prevention against any accidental exposure that can occur in a microbiological laboratory.

Ezurpimtrostat, A Palmitoyl-Protein Thioesterase-1 Inhibitor, Combined with PD-1 Inhibition Provides CD8+ Lymphocyte Repopulation in Hepatocellular Carcinoma

BACKGROUND

Palmitoyl-protein thioesterase-1 (PPT1) is a clinical stage druggable target for inhibiting autophagy in cancer.

OBJECTIVE

We aimed to determine the cellular and molecular activity of targeting PPT1 using ezurpimtrostat, in combination with an anti-PD-1 antibody.

METHODS

In this study we used a transgenic immunocompetent mouse model of hepatocellular carcinoma.

RESULTS

Herein, we revealed that inhibition of PPT1 using ezurpimtrostat decreased the liver tumor burden in a mouse model of hepatocellular carcinoma by inducing the penetration of lymphocytes into tumors when combined with anti-programmed death-1 (PD-1). Inhibition of PPT1 potentiates the effects of anti-PD-1 immunotherapy by increasing the expression of major histocompatibility complex (MHC)-I at the surface of liver cancer cells and modulates immunity through recolonization and activation of cytotoxic CD8+ lymphocytes.

CONCLUSIONS

Ezurpimtrostat turns cold tumors into hot tumors and, thus, could improve T cell-mediated immunotherapies in liver cancer.

Evaluation of the interest to combine a CD4 Th1-inducer cancer vaccine derived from telomerase and atezolizumab plus bevacizumab in unresectable hepatocellular carcinoma: a randomized non-comparative phase II study (TERTIO - PRODIGE 82)

BACKGROUND

Several cancer immunotherapies that target the PD-L1/PD-1 pathway show promising clinical activity in patients with hepatocellular carcinoma (HCC). However, the standard of care in first-line treatment with atezolizumab (anti-PD-L1 therapy) in combination with bevacizumab is associated with a limited objective response rate. Telomerase reverse transcriptase (TERT) activation meets the criteria of oncogenic addiction in HCC and could be actionable therapeutic target and a relevant tumor antigen. Therefore we hypothesized that combining anti-PD-1/PD-L1 therapy with an anti-telomerase vaccine might be an attractive therapy in HCC. UCPVax is a therapeutic cancer vaccine composed of two separate peptides derived from telomerase (human TERT). UCPVax has been evaluated in a multicenter phase I/II study in non-small cell lung cancers and has demonstrated to be safe and immunogenic, and is under evaluation in combination with atezolizumab in a phase II clinical trial in tumors where telomerase reactivation contributes to an oncogene addiction (HPV⁺ cancers). The aim of the TERTIO study is to determine the clinical interest and immunological efficacy of a treatment combining the CD4 helper T-inducer cancer anti-telomerase vaccine (UCPVax) with atezolizumab and bevacizumab in unresectable HCC in a multicenter randomized phase II study.

METHODS

Patients with locally advanced, metastatic or unresectable HCC who have not previously received systemic anti-cancer treatment are eligible. The primary end point is the objective response rate at 6 months. Patients will be allocated to a treatment arm with a randomization 2:1. In both arms, patients will receive atezolizumab at fixed dose of 1200 mg IV infusion and bevacizumab at fixed dose of 15 mg/kg IV infusion, every 3 weeks, according to the standard of care. In the experimental arm, these treatments will be combined with the UCPVax vaccine at 0.5 mg subcutaneously.

DISCUSSION

Combining anti-PD-1/PD-L1 therapy with an anti-telomerase vaccine gains serious consideration in HCC, in order to extend the clinical efficacy of anti-PD-1/PD-L1. Indeed, anti-cancer vaccines can induce tumor-specific T cell expansion and activation and therefore restore the cancer-immunity cycle in patients lacking pre-existing anti-tumor responses. Thus, there is a strong rational to combine immune checkpoint blockade therapy and anticancer vaccine (UCPVax) in order to activate antitumor T cell immunity and bypass the immunosuppression in the tumor microenvironment in HCC. This pivotal proof of concept study will evaluate the efficacy and safety of the combination of a CD4 Th1-inducer cancer vaccine derived from telomerase (UCPVax) and atezolizumab plus bevacizumab in unresectable HCC, as well as confirming their synergic mechanism, and settling the basis for a new combination for future clinical trials.

TRIAL REGISTRATION

NCT05528952.

Sex differences on multikinase inhibitors toxicity in patients with advanced gastroenteropancreatic neuroendocrine tumours

PURPOSE

There is an increasing interest in the role of sex and gender in cancer patients. The impact of sex differences in oncological systemic therapies is still unknown, and there is a lack of evidence specially in uncommon neoplasms like neuroendocrine tumours (NET). In the present study, we combine the differential toxicities by sex in five published clinical trials with multikinase inhibitors (MKI) in gastroenteropancreatic (GEP) NET.

METHODS

We performed a pooled univariate analysis of reported toxicity in patients treated in five phase 2 and phase 3 clinical trials with MKI in the GEP NET setting: sunitinib (SU11248, SUN1111), Pazopanib (PAZONET), sorafenib-bevacizumab (GETNE0801) and Lenvatinib (TALENT). Differential toxicities between male and female patients were evaluated considering relationship with study drug and different weights of each trial by random effect adjustment.

RESULTS

We found nine toxicities which were more frequent in female patients (leukopenia, alopecia, vomiting, headache, bleeding, nausea, dysgeusia, neutrophil count decreased and dry mouth) and two toxicities being more frequent in male patients (Anal Symptoms and Insomnia). Asthenia and diarrhoea were the only severe (Grade 3-4) toxicities more frequent in female patients.

CONCLUSIONS

Sex-related differences in toxicity with the MKI treatment require targeted information and individualised management of patients with NET. Differential reporting of toxicity should be promoted when clinical trials are published.

Methods for Inclusive Underwriting of Breast Cancer Risk with Machine Learning and Innovative Algorithms

INTRODUCTION

-Due to early detection and improved therapies, the prevalence of long-term breast cancer survivors is increasing. This has increased the need for more inclusive underwriting in individuals with a history of breast cancer. Herein, we developed a method using algorithm aiming facilitating the underwriting of multiple parameters in breast cancer survivors.

METHODS

-Variables and data were extracted from the SEER database and analyzed using 4 different machine learning based algorithms (Logistic Regression, GA2M, Random Forest, and XGBoost) that were compared with Kaplan Meier survival estimates. The performances of these algorithms have been compared with multiple metrics (Log Loss, AUC, and SMR). In situ (non-invasive) and metastatic breast cancer were excluded from this analysis.

RESULTS

-Parameters included the pathological subtype, pTNM staging (T: tumor size, N; number of nodes; M presence or absence of metastases), Scarff-Bloom-Richardson grading, the expression of estrogen and progesterone hormone receptors were selected to predict the individual outcome at any time point from diagnosis. While all models had identical performance in terms of statistical metrics (AUC, Log Loss, and SMR), the logistic regression was the one and only model that respects all business constraints and was intelligible for medical and underwriting users.

CONCLUSION

-This study provides insight to develop algorithms to set underwriter-friendly calculators for more accurate risk estimations that can be used to rationalize insurance pricing for breast cancer survivors. This study supports the development of a more inclusive underwriting based on models that can encompass the heterogeneity of several malignancies such as breast cancer.

Update on Autophagy Inhibitors in Cancer: Opening up to a Therapeutic Combination with Immune Checkpoint Inhibitors

Autophagy is a highly conserved and natural degradation process that helps maintain cell homeostasis through the elimination of old, worn, and defective cellular components, ensuring proper cell energy intake. The degradative pathway constitutes a protective barrier against diverse human diseases including cancer. Autophagy basal level has been reported to be completely dysregulated during the entire oncogenic process. Autophagy influences not only cancer initiation, development, and maintenance but also regulates cancer response to therapy. Currently, autophagy inhibitor candidates mainly target the early autophagy process without any successful preclinical/clinical development. Lessons learned from autophagy pharmaceutical manipulation as a curative option progressively help to improve drug design and to encounter new targets of interest. Combinatorial strategies with autophagy modulators are supported by abundant evidence, especially dealing with immune checkpoint inhibitors, for which encouraging preclinical results have been recently published. GNS561, a PPT1 inhibitor, is a promising autophagy modulator as it has started a phase 2 clinical trial in liver cancer indication, combined with atezolizumab and bevacizumab, an assessment without precedent in the field. This approach paves a new road, leading to the resurgence of anticancer autophagy inhibitors as an attractive therapeutic target in cancer.

Tislelizumab plus chemotherapy versus placebo plus chemotherapy as first-line treatment for advanced or metastatic oesophageal squamous cell carcinoma (RATIONALE-306): a global, randomised, placebo-controlled, phase 3 study

BACKGROUND

The options for first-line treatment of advanced oesophageal squamous cell carcinoma are scarce, and the outcomes remain poor. The anti-PD-1 antibody, tislelizumab, has shown antitumour activity in previously treated patients with advanced oesophageal squamous cell carcinoma. We report interim analysis results from the RATIONALE-306 study, which aimed to assess tislelizumab plus chemotherapy versus placebo plus chemotherapy as first-line treatment for advanced or metastatic oesophageal squamous cell carcinoma.

METHODS

This global, randomised, double-blind, parallel-arm, placebo-controlled, phase 3 study was conducted at 162 medical centres across Asia, Europe, Oceania, and North America. Patients (aged ≥18 years) with unresectable, locally advanced, recurrent or metastatic oesophageal squamous cell carcinoma (regardless of PD-L1 expression), Eastern Cooperative Oncology Group performance status of 0-1, and measurable or evaluable disease per Response Evaluation Criteria in Solid Tumours (version 1.1) were recruited. Patients were randomly assigned (1:1), using permuted block randomisation (block size of four) and stratified by investigator-chosen chemotherapy, region, and previous definitive therapy, to tislelizumab 200 mg or placebo intravenously every 3 weeks on day 1, together with an investigator-chosen chemotherapy doublet, comprising a platinum agent (cisplatin 60-80 mg/m2 intravenously on day 1 or oxaliplatin 130 mg/m2 intravenously on day 1) plus a fluoropyrimidine (fluorouracil [750-800 mg/m2 intravenously on days 1-5] or capecitabine [1000 mg/m2 orally twice daily on days 1-14]) or paclitaxel (175 mg/m2 intravenously on day 1). Treatment was continued until disease progression or unacceptable toxicity. Investigators, patients, and sponsor staff or designees were masked to treatment. The primary endpoint was overall survival. The efficacy analysis was done in the intention-to-treat population (ie, all randomly assigned patients) and safety was assessed in all patients who received at least one dose of study treatment. The trial is registered with ClinicalTrials.gov, NCT03783442.

FINDINGS

Between Dec 12, 2018, and Nov 24, 2020, 869 patients were screened, of whom 649 were randomly assigned to tislelizumab plus chemotherapy (n=326) or placebo plus chemotherapy (n=323). Median age was 64·0 years (IQR 59·0-69·0), 563 (87%) of 649 participants were male, 86 (13%) were female, 486 (75%) were Asian, and 155 (24%) were White. 324 (99%) of 326 patients in the tislelizumab group and 321 (99%) of 323 in the placebo group received at least one dose of the study drug. As of data cutoff (Feb 28, 2022), median follow-up was 16·3 months (IQR 8·6-21·8) in the tislelizumab group and 9·8 months (IQR 5·8-19·0) in the placebo group, and 196 (60%) of 326 patients in the tislelizumab group versus 226 (70%) of 323 in the placebo group had died. Median overall survival in the tislelizumab group was 17·2 months (95% CI 15·8-20·1) and in the placebo group was 10·6 months (9·3-12·1; stratified hazard ratio 0·66 [95% CI 0·54-0·80]; one-sided p<0·0001). 313 (97%) of 324 patients in the tislelizumab group and 309 (96%) of 321 in the placebo group had treatment-related treatment-emergent adverse events. The most common grade 3 or 4 treatment-related treatment-emergent adverse events were decreased neutrophil count (99 [31%] in the tislelizumab group vs 105 [33%] in the placebo group), decreased white blood cell count (35 [11%] vs 50 [16%]), and anaemia (47 [15%] vs 41 [13%]). Six deaths in the tislelizumab group (gastrointestinal and upper gastrointestinal haemorrhage [n=2], myocarditis [n=1], pulmonary tuberculosis [n=1], electrolyte imbalance [n=1], and respiratory failure [n=1]) and four deaths in the placebo group (pneumonia [n=1], septic shock [n=1], and unspecified death [n=2]) were determined to be treatment-related.

INTERPRETATION

Tislelizumab plus chemotherapy as a first-line treatment for advanced or metastatic oesophageal squamous cell carcinoma provided superior overall survival with a manageable safety profile versus placebo plus chemotherapy. Given that the interim analysis met its superiority boundary for the primary endpoint, as confirmed by the independent data monitoring committee, this Article represents the primary study analysis.

FUNDING

BeiGene.

Prognostic Factors of Long-Term Outcomes after Primary Chemo-Radiotherapy in Non-Metastatic Anal Squamous Cell Carcinoma: An International Bicentric Cohort

Anal squamous cell carcinoma (ASCC) is a rare malignancy with a rising incidence associated with human papillomavirus (HPV) infection. The locally advanced disease is associated with a 30% rate of treatment failure after standard chemoradiotherapy (CRT). We aimed to elucidate the prognostic factors for ASCC after curative CRT. A retrospective multicenter study of 176 consecutive patients with ASCC having completed CRT treated between 2010 and 2017 at two centers was performed. Complete response (CR), disease-free survival (DFS), and overall survival (OS) were analyzed by Kaplan–Meier estimates with log-rank tests. The hierarchical clustering on principal components (HCPC) method was employed in an unsupervised and multivariate approach. The CR rate was 70% and was predictive of DFS (p < 0.0001) and OS (p < 0.0001), where non-CR cases were associated with shorter DFS (HR = 16.5, 95% CI 8.19–33.21) and OS (HR = 8.42, 95% CI 3.77–18.81) in a univariate analysis. The median follow-up was 38 months, with a 3-year DFS of 71%. The prognostic factors for DFS were cT1-T2 (p = 0.0002), N0 (p = 0.035), HIV-positive (p = 0.047), HIV-HPV coinfection (p = 0.018), and well-differentiated tumors (p = 0.037). The three-year OS was 81.6%. Female sex (p = 0.05), cT1-T2 (p = 0.02) and well-differentiated tumors (p = 0.003) were associated with better OS. The unsupervised analysis demonstrated a clear segregation of patients in three clusters, identifying that poor prognosis clusters associated with shorter DFS (HR = 1.74 95% CI = 1.25–2.42, p = 0.0008) were enriched with the locally advanced disease, anal canal location, HIV-HPV coinfection, and non-CR. In conclusion, our results reinforce the prognostic value of T stage, N stage, sex, differentiation status, tumor location, and HIV-HPV coinfection in ASCC after CRT.

Randomized, global, phase 3 study of tislelizumab (TIS) + chemotherapy (chemo) versus placebo (PBO) + chemo as first-line (1L) treatment for advanced or metastatic esophageal squamous cell carcinoma (ESCC) (RATIONALE-306): Non-Asia subgroup

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Background: TIS, an anti-programmed cell death protein 1 (PD-1) antibody, + chemo as 1L therapy demonstrated statistically significant and clinically meaningful improvement in overall survival (OS) vs PBO + chemo in patients with advanced or metastatic ESCC (hazard ratio [HR] 0.66 [95% confidence interval (CI) 0.54, 0.80]; P< 0.0001), with a manageable safety profile, at interim analysis of the phase 3, double-blind RATIONALE-306 study (NCT03783442). Here, we report data from the non-Asia subgroup (Europe, Northern America, and Oceania). Methods: Adults with advanced or metastatic ESCC, with no prior systemic treatment for advanced disease were randomized 1:1, (stratified by region, prior definitive therapy, and investigator [INV]-chosen chemo) to receive TIS 200 mg intravenously (IV) once every 3 weeks (Q3W) (Arm A) or PBO IV Q3W (Arm B), with platinum + fluoropyrimidine, or platinum + paclitaxel until disease progression by INV per RECIST v1.1, intolerable toxicity, or withdrawal. The primary endpoint was OS in the intent-to-treat population. Secondary endpoints included: progression-free survival (PFS), objective response rate (ORR), and duration of response (DoR) by INV per RECIST v1.1; OS in the programmed death-ligand 1 score ≥10%; and safety. Results: Of 649 randomized patients, 163 (25.1%) were from the non-Asia subgroup (Arm A, n = 83; Arm B, n = 80). At data cutoff (Feb 28, 2022), the median study follow-up time in the non-Asia subgroup was 16.0 months (mo) in Arm A vs 8.4 mo in Arm B. OS (median 16.3 vs 9.0 mo; unstratified HR 0.66 [95% CI 0.45, 0.96]) and PFS (median 7.7 vs 5.5 mo; unstratified HR 0.59 [95% CI 0.41, 0.83]) were improved in Arm A vs Arm B, respectively. Arm A had higher ORR (61.4% vs 41.3%, odds ratio 2.27 [95% CI 1.21, 4.25]) and longer median DoR (7.1 mo [95% CI 5.6, 9.6] vs 5.7 mo [95% CI 3.8, 8.3]) than Arm B. More patients in Arm A vs Arm B experienced ≥1 treatment-related adverse event (TRAE; 94.0% vs 88.5%), serious TRAEs (25.3% vs 17.9%), and discontinuation due to treatment-emergent AEs (42.2% vs 35.9%, respectively). Similar proportions of patients in Arm A vs Arm B had ≥grade 3 TRAEs (56.6% vs 52.6%), and TRAEs leading to death (1.2% vs 1.3%), respectively. Conclusions: In the non-Asia subgroup, 1L TIS + chemo showed a clinically meaningful improvement in OS vs PBO + chemo in patients with advanced or metastatic ESCC, with a manageable safety profile, consistent with published results in the overall population. Clinical trial information: NCT03783442 .

A transcriptomics approach to expand therapeutic options and optimize clinical trials in oncology

Background:

The current model of clinical drug development in oncology displays major limitations due to a high attrition rate in patient enrollment in early phase trials and a high failure rate of drugs in phase III studies.

Objective:

Integrating transcriptomics for selection of patients has the potential to achieve enhanced speed and efficacy of precision oncology trials for any targeted therapies or immunotherapies.

Methods:

Relative gene expression level in the metastasis and normal organ-matched tissues from the WINTHER database was used to estimate in silico the potential clinical benefit of specific treatments in a variety of metastatic solid tumors.

Results:

As example, high mRNA expression in tumor tissue compared to analogous normal tissue of c-MET and its ligand HGF correlated in silico with shorter overall survival (OS; p < 0.0001) and may constitute an independent prognostic marker for outcome of patients with metastatic solid tumors, suggesting a strategy to identify patients most likely to benefit from MET-targeted treatments. The prognostic value of gene expression of several immune therapy targets (PD-L1, CTLA4, TIM3, TIGIT, LAG3, TLR4) was investigated in non-small-cell lung cancers and colorectal cancers (CRCs) and may be useful to optimize the development of their inhibitors, and opening new avenues such as use of anti-TLR4 in treatment of patients with metastatic CRC.

Conclusion:

This in silico approach is expected to dramatically decrease the attrition of patient enrollment and to simultaneously increase the speed and detection of early signs of efficacy. The model may significantly contribute to lower toxicities. Altogether, our model aims to overcome the limits of current approaches.

Targeting the Tumor Microenvironment through mTOR Inhibition and Chemotherapy as Induction Therapy for Locally Advanced Head and Neck Squamous Cell Carcinoma: The CAPRA Study

Simple Summary

The PI3K-AKT-mTOR pathway is dysregulated in 70% of head and neck squamous cell carcinoma (HNSCC) and linked to the tumor microenvironment. This weekly induction treatment combined the mTOR inhibitor everolimus with carboplatin-paclitaxel chemotherapy for locally advanced T3-4/N0-3 HNSCC. In 41 patients, safety profile was favorable and overall response rate was 75.6%. Translational data demonstrated specific target engagement with p-S6K decrease in tumor tissue and pro-immunogenic cytokine release in peripheral blood. Induction treatment with chemotherapy and mTOR inhibitors may provide new therapeutic options and rationale for combinations with immune oncology agents for locally advanced HNSCC.

Abstract

Mammalian target of rapamycin (mTOR) regulates cellular functions by integrating intracellular signals and signals from the tumor microenvironment (TME). The PI3K-AKT-mTOR pathway is activated in 70% of head and neck squamous cell carcinoma (HNSCC) and associated with poor prognosis. This phase I-II study investigated the effect of mTOR inhibition using weekly everolimus (30 mg for dose level 1, 50 mg for dose level 2) combined with weekly induction chemotherapy (AUC2 carboplatin and 60 mg/m² paclitaxel) in treatment-naïve patients with locally advanced T3-4/N0-3 HNSCC. Patients received 9 weekly cycles before chemoradiotherapy. Objectives were safety and antitumor activity along with tissue and blood molecular biomarkers. A total of 50 patients were enrolled. Among 41 evaluable patients treated at the recommended dose of 50 mg everolimus weekly, tolerance was good and overall response rate was 75.6%, including 20 major responses (≥50% reduction in tumor size). A significant decrease in expression of p-S6K (p-value: 0.007) and Ki67 (p-value: 0.01) was observed in post-treatment tumor tissue. Pro-immunogenic cytokine release (Th1 cytokines IFN-γ, IL-2, and TNF-β) was observed in the peripheral blood. The combination of everolimus and chemotherapy in HNSCC was safe and achieved major tumor responses. This strategy favorably impacts the TME and might be combined with immunotherapeutic agents.

Transcriptomics in Tumor and Normal Lung Tissues Identify Patients With Early-Stage Non-Small-Cell Lung Cancer With High Risk of Postsurgery Recurrence Who May Benefit From Adjuvant Therapies

PURPOSE

The prognosis of patients with non-small-cell lung cancer (NSCLC), traditionally determined by anatomic histology and TNM staging, neglects the biological features of the tumor that may be important in determining patient outcome and guiding therapeutic interventions. Identifying patients with NSCLC at increased risk of recurrence after curative-intent surgery remains an important unmet need so that known effective adjuvant treatments can be offered to those at highest risk of recurrence.

METHODS

Relative gene expression level in the primary tumor and normal bronchial tissues was used to retrospectively assess their association with disease-free survival (DFS) in a cohort of 120 patients with NSCLC who underwent curative-intent surgery.

RESULTS

Low versus high Digital Display Precision Predictor (DDPP) score (a measure of relative gene expression) was significantly associated with shorter DFS (highest recurrence risk; P = .006) in all patients and in patients with TNM stages 1-2 (P = .00051; n = 83). For patients with stages 1-2 and low DDPP score (n = 29), adjuvant chemotherapy was associated with improved DFS (P = .0041). High co-overexpression of CTLA-4, PD-L1, and ICOS in normal lung (28 of 120 patients) was also significantly associated with decreased DFS (P = .0013), suggesting an immune tolerance to tumor neoantigens in some patients. Patients with DDPP low and immunotolerant normal tissue had the shortest DFS (P = 2.12E-11).

CONCLUSION

TNM stage, DDPP score, and immune competence status of normal lung are independent prognostic factors in multivariate analysis. Our findings open new avenues for prospective prognostic assessment and treatment assignment on the basis of transcriptomic profiling of tumor and normal lung tissue in patients with NSCLC.

Quality of life in patients with advanced high-grade ovarian cancer (HGOC) receiving maintenance therapies after first-line (1L) chemotherapy in the randomized phase III PAOLA-1/ENGOT-ov25 trial (NCT02477644)

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Background: In the Phase III PAOLA-1/ENGOT-ov25 trial, maintenance olaparib + bevacizumab (bev) provided a significant progression-free survival (PFS) benefit vs placebo (pbo) + bev in patients (pts) with newly diagnosed advanced ovarian cancer in response to platinum-based chemotherapy. Subgroup analyses revealed a substantial PFS benefit in homologous recombination deficiency (HRD)-positive (including BRCA1/2 mutation) pts, leading to US/EU labels for this combination. Preliminary analyses reported that olaparib did not alter global health-related quality of life (G-HQoL; Ray-Coquard I et al. NEJM 2019). We analyzed HQoL by domains and molecular subgroups and explored the impact of disease progression (DP) on HQoL in the 1L setting. Methods: Eligible pts with newly diagnosed advanced (FIGO stage III–IV) HGOC were randomized 2:1 to maintenance olaparib + bev or pbo + bev. Pts completed European Organisation for Research and Treatment of Cancer QLQ-C30 and QLQ-OV28 HQoL questionnaires at baseline and every 12 weeks for 2 years’ follow-up, irrespective of DP. The minimal important difference for clinically relevant change was fixed at 10 points. Longitudinal data were analyzed by mixed model for repeated measures (MMRM) and time until definitive deterioration (TUDD). Analyses were in the intent-to-treat population and HRD-positive subgroup. HQoL analyses at DP (± 60 days) were explored. Results: 806 pts were randomized to olaparib + bev (n=537) or pbo + bev (n=269). 465 pts had DP over 2 years’ follow-up. Compliance to HQoL questionnaires was high at baseline (95%) and over time (>70%). MMRM models by HQoL domain did not reveal a clinically relevant difference between treatment arms over time. TUDD of G-HQoL did not differ between arms (hazard ratio [HR] 0.88, 95% confidence interval [CI] 0.72–1.07). In the HRD-positive subgroup (n=372), we observed no difference by HQoL domain between treatment arms. Interestingly, TUDD of G-HQoL was statistically significantly in favor of olaparib + bev compared with pbo + bev (HR 0.70, 95% CI 0.52–0.93). We also observed a clinically significant deterioration in emotional (mean change −12.30 points, 95% CI −16.46 to −8.13) and social (−11.17 points, 95% CI −16.21 to −6.12) functioning in both treatment arms at DP, among 103 pts with HQoL questionnaires at DP. Conclusions: The substantial PFS benefit provided by maintenance olaparib + bev in the newly diagnosed setting was achieved without detrimental effect on HQoL domains, even with longer TUDD of G-HQoL in the HRD-positive subgroup. Use of an effective maintenance therapy (ie one with a significant PFS benefit) in HGOC patients in the 1L setting is likely to delay the clinically significant deterioration in emotional and social functioning we identified in patients at DP across PAOLA-1 treatments arms. Clinical trial information: NCT02477644.

ENETS standardized (synoptic) reporting for molecular imaging studies in neuroendocrine tumours

The European Neuroendocrine Tumor Society (ENETS) promotes practices and procedures that aim to improve the standard of care delivered to patients diagnosed with or suspected of having neuroendocrine neoplasia (NEN). At its annual Scientific Advisory Board Meeting in 2018, experts in imaging, pathology and clinical care of patients with NEN drafted guidance for the standardised reporting of diagnostic studies critical to the diagnosis, grading, staging and treatment of NEN. These included pathology, radiology, endoscopy and molecular imaging procedures. In an iterative process, a synoptic reporting template for molecular imaging procedures was developed to guide personalised therapies. Following pilot implementation and refinement within the ENETS Center of Excellence network, harmonisation with specialist imaging societies including the Society of Nuclear Medicine, European Association of Nuclear Medicine and the International Cancer Imaging Society will be pursued.

First-In-Human Effects of PPT1 Inhibition Using the Oral Treatment with GNS561/Ezurpimtrostat in Patients with Primary and Secondary Liver Cancers

INTRODUCTION

GNS561/Ezurpimtrostat is a first-in-class, orally bioavailable, small molecule that blocks cancer cell proliferation by inhibiting late-stage autophagy and dose-dependent build-up of enlarged lysosomes by interacting with the palmitoyl-protein thioesterase 1 (PPT1).

METHODS

This phase I, open-label, dose-escalation trial (3 + 3 design) explored two GNS561 dosing schedules: one single oral intake 3 times a week (Q3W) and twice daily (BID) continuous oral administration in patients with advanced hepatocellular carcinoma, cholangiocarcinoma, and pancreatic adenocarcinoma or colorectal adenocarcinomas with liver metastasis. The primary objective was to determine GNS561 recommended phase II dose (RP2D) and schedule. Secondary objectives included evaluation of the safety/tolerability, pharmacokinetics, pharmacodynamics, and antitumor activity of GNS561.

RESULTS

Dose escalation ranged from 50 to 400 mg Q3W to 200-300 mg BID. Among 26 evaluable patients for safety, 20 were evaluable for efficacy and no dose-limiting toxicity was observed. Adverse events (AEs) included gastrointestinal grade 1-2 events, primarily nausea and vomiting occurred in 13 (50%) and 14 (54%) patients, respectively, and diarrhea in 11 (42%) patients. Seven grade 3 AEs were reported (diarrhea, decreased appetite, fatigue, alanine aminotransferase, and aspartate aminotransferase increased). Q3W administration was associated with limited exposure and the BID schedule was preferred. At 200 mg BID GNS561, plasma and liver concentrations were comparable to active doses in animal models. Liver trough concentrations were much higher than in plasma a median time of 28 days of administration with a mean liver to plasma ratio of 9,559 (Min 149-Max 25,759), which is in accordance with rat preclinical data observed after repeated administration. PPT1 expression in cancer tissues in the liver was reduced upon GNS561 exposure. There was no complete or partial response. Five patients experienced tumor stable diseases (25%), including one minor response (-23%).

CONCLUSION

Based on a favorable safety profile, exposure, and preliminary signal of activity, oral GNS561 RP2D was set at 200 mg BID. Studies to evaluate the antitumor activity of GNS561 in hepatocarcinoma cells and intrahepatic cholangiocarcinoma are to follow NCT03316222.

GNS561, a clinical-stage PPT1 inhibitor, is efficient against hepatocellular carcinoma via modulation of lysosomal functions

Hepatocellular carcinoma is the most frequent primary liver cancer. Macroautophagy/autophagy inhibitors have been extensively studied in cancer but, to date, none has reached efficacy in clinical trials. In this study, we demonstrated that GNS561, a new autophagy inhibitor, whose anticancer activity was previously linked to lysosomal cell death, displayed high liver tropism and potent antitumor activity against a panel of human cancer cell lines and in two hepatocellular carcinoma in vivo models. We showed that due to its lysosomotropic properties, GNS561 could reach and specifically inhibited its enzyme target, PPT1 (palmitoyl-protein thioesterase 1), resulting in lysosomal unbound Zn²⁺ accumulation, impairment of cathepsin activity, blockage of autophagic flux, altered location of MTOR (mechanistic target of rapamycin kinase), lysosomal membrane permeabilization, caspase activation and cell death. Accordingly, GNS561, for which a global phase 1b clinical trial in liver cancers was just successfully achieved, represents a promising new drug candidate and a hopeful therapeutic strategy in cancer treatment.

Abbreviations: ANXA5:annexin A5; ATCC: American type culture collection; BafA1: bafilomycin A₁; BSA: bovine serum albumin; CASP3: caspase 3; CASP7: caspase 7; CASP8: caspase 8; CCND1: cyclin D1; CTSB: cathepsin B; CTSD: cathepsin D; CTSL: cathepsin L; CQ: chloroquine; iCCA: intrahepatic cholangiocarcinoma; DEN: diethylnitrosamine; DMEM: Dulbelcco’s modified Eagle medium; FBS: fetal bovine serum; FITC: fluorescein isothiocyanate; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; HCC: hepatocellular carcinoma; HCQ: hydroxychloroquine; HDSF: hexadecylsulfonylfluoride; IC₅₀: mean half-maximal inhibitory concentration; LAMP: lysosomal associated membrane protein; LC3-II: phosphatidylethanolamine-conjugated form of MAP1LC3; LMP: lysosomal membrane permeabilization; MALDI: matrix assisted laser desorption ionization; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MKI67: marker of proliferation Ki-67; MTOR: mechanistic target of rapamycin kinase; MRI: magnetic resonance imaging; NH₄Cl: ammonium chloride; NtBuHA: N-tert-butylhydroxylamine; PARP: poly(ADP-ribose) polymerase; PBS: phosphate-buffered saline; PPT1: palmitoyl-protein thioesterase 1; SD: standard deviation; SEM: standard error mean; vs, versus; Zn²⁺: zinc ion; Z-Phe: Z-Phe-Tyt(tBu)-diazomethylketone; Z-VAD-FMK: carbobenzoxy-valyl-alanyl-aspartyl-[O-methyl]- fluoromethylketone.

Posterior Reversible Encephalopathy Occurring During Treatment With Palbociclib

Palbociclib (Ibrance™) has been marketed since 2015 for patients with metastatic hormone-receptor-positive breast cancer. We report here the case of a patient who presented with a posterior reversible encephalopathy syndrome (PRES) during treatment with this new targeted therapy.

The 67-year-old woman presented prodromal headaches followed by occurrences of two episodes of generalized convulsive seizures. The brain MRI revealed a bilateral, globally symmetrical, sub-cortical parietooccipital fluid-attenuated inversion recovery (FLAIR) hypersignal of the white matter.

The patient recovered after palbociclib discontinuation with no further neurological signs. A follow-up MRI performed one month upon palbociclib discontinuation showed a decrease in the FLAIR signal abnormalities. Altogether, the clinical presentation was consistent with PRES.

This case report aims to encourage physicians whom patients are treated with cyclin-dependent kinase 4/6 inhibitors to cautiously monitor symptoms suggesting PRES in contexts known to promote its occurrence such as that of arterial hypertension, immunosuppression, and/or autoimmune disease. PRES should be considered in the event of seizure, headache, and/or visual disturbances.

Phase 1b/2 trial of tepotinib in sorafenib pretreated advanced hepatocellular carcinoma with MET overexpression

BACKGROUND

This Phase 1b/2 study evaluated tepotinib, a highly selective MET inhibitor, in US/European patients with sorafenib pretreated advanced hepatocellular carcinoma (aHCC) with MET overexpression.

METHODS

Eligible adults had aHCC, progression after ≥4 weeks of sorafenib, and, for Phase 2 only, MET overexpression. Tepotinib was administered once daily at 300 or 500 mg in Phase 1b ('3 + 3' design), and at the recommended Phase 2 dose (RP2D) in Phase 2. Primary endpoints were dose-liming toxicities (DLTs; Phase 1b) and 12-week investigator-assessed progression-free survival (PFS; Phase 2).

RESULTS

In Phase 1b (n = 17), no DLTs occurred and the RP2D was confirmed as 500 mg. In Phase 2 (n = 49), the primary endpoint was met: 12-week PFS was 63.3% (90% CI: 50.5-74.7), which was significantly greater than the predefined null hypothesis of ≤15% (one-sided binomial exact test: P < 0.0001). Median time to progression was 4 months. In Phase 2, 28.6% of patients had treatment-related Grade ≥3 adverse events, including peripheral oedema and lipase increase (both 6.1%).

CONCLUSIONS

Tepotinib was generally well tolerated and the RP2D (500 mg) showed promising efficacy and, therefore, a positive benefit-risk balance in sorafenib pretreated aHCC with MET overexpression.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02115373.

First-in-human phase I, pharmacokinetic (PK), and pharmacodynamic (PD) study of oral GNS561, a palmitoyl-protein thioesterase 1 (PPT1) inhibitor, in patients with primary and secondary liver malignancies

e16175

Background: GNS561 belongs to a novel generation of drug blocking cancer cell proliferation by inhibiting late-stage autophagy and dose-dependent accumulation of enlarged lysosomes by interacting with palmitoyl-protein thioesterase-1 (PPT1). Methods: This phase I, multicenter, open-label, dose-escalation trial (3+3 design) explored two dosing schedules: one single oral intake three times a week and twice daily (BID) continuous oral intake of GNS561 in patients with advanced primary and secondary liver cancers (NCT03316222). The primary objective was to determine recommended phase II dose (RP2D) and schedule for further clinical development. The secondary objectives included a preliminary evaluation of the safety, pharmacokinetic (PK), pharmacodynamics (PD), and antitumor activity of GNS561. Results: Nineteen treatment-refractory patients were enrolled and were evaluable for primary endpoint: intrahepatic cholangiocarcinoma (iCCA) (9), hepatocellular carcinoma (HCC) (7), pancreatic ductal adenocarcinoma (PDAC) (2) and colorectal cancer (CRC) (1). Median age was 60, 89% were male and 37% had received 3 or more lines as prior cancer therapies. Dose escalation ranged from 50 mg three times a week to 200 mg BID. No dose-limiting toxicity were observed. Treatment-related adverse events were grade 1-2 gastrointestinal toxicity, primarily nausea/vomiting, occurring in 8 patients (42%) and diarrhea in 4 patients (21%). Occurrence of nausea/vomiting despite antiemetic prophylaxis prevented increasing doses above 200 mg BID. GNS561 displayed favorable bioavailability with interpatient variability (CV%: 13 to 223% and 21 to 98.2% on plasma concentrations on cycle 1 day 1 and cycle 2 day 1 respectively), and dose proportional exposure in plasma. GNS561 concentrations accumulated after multiple administration (2.60 - 9.00-fold) and exhibited a long half-life. Plasma and liver concentrations at doses ranging 100-200 mg BID were comparable to therapeutic exposures in preclinical models. Five patients (3 HCC and 2 iCCA) experienced tumor stabilization according to RECIST 1.1 criteria, including a minor response (-23%). Conclusions: GNS561 RP2D single agent was set at 200 mg BID based on this favorable safety profile and plasma exposure, GNS561 will be next further evaluated in monotherapy and in combination with checkpoint inhibitors considering the autophagic activity restriction of major histocompatibility complex-1 promotion of immune invasion. Clinical trial information: NCT03316222.

Updated Efficacy and Safety Outcomes for Patients with Well-Differentiated Pancreatic Neuroendocrine Tumors Treated with Sunitinib

BACKGROUND

Sunitinib prolonged progression-free survival (PFS) versus placebo in patients with metastatic pancreatic neuroendocrine tumors (panNETs) in a phase III trial. The efficacy and safety of sunitinib in patients with panNETs were confirmed in an open-label phase IV trial.

OBJECTIVE

To assess the clinical benefit with sunitinib using the combined data from these trials.

PATIENTS AND METHODS

An updated overall survival (OS) in patients with panNETs for the phase IV trial was provided, and an analysis of results from the sunitinib-treated combined cohort from the phase III and IV trials (combined cohort) was conducted to assess PFS, OS, and objective response rate (ORR).

RESULTS

The updated median OS for the phase IV trial was 54.1 months (95% CI 37.9-not reached). Investigator-assessed median PFS for the combined cohort (n = 102) was 12.9 months (95% CI 7.4-16.7) with a significant benefit versus placebo in the phase III trial (n = 35) (HR 0.429; 95% CI 0.245-0.752; p = 0.001). Median OS could not be calculated for the combined cohort or placebo group due to the high number of patients censored; however, the estimated HR of 0.303 (CI 0.100-0.921; p = 0.013) favored sunitinib. ORR for the combined cohort was 16.7% (95% CI 10.0-25.3). Sunitinib was well tolerated in both trials with a safety profile similar to previously seen in other studies.

CONCLUSIONS

The combined analysis of these studies confirms the objective tumor responses and improvements in PFS observed in the initial phase III trial, providing further support for the clinical benefit of sunitinib in patients with advanced panNETs. CLINICALTRIALS.

GOV IDENTIFIERS

NCT00428597 and NCT01525550.

PD-L1 expression in the microenvironment and the response to checkpoint inhibitors in head and neck squamous cell carcinoma

In head and neck squamous cell carcinoma (HNSCC), data from studies using checkpoint-inhibiting antibodies that target programmed death 1 (PD-1) or its ligand the programmed death ligand 1 (PD-L1) demonstrated outstanding clinical activity. Translational investigations also suggested some correlations between therapeutic response and PD-L1 expression in tumor tissue. We comprehensively summarize results that have evaluated PD-L1 expression in HNSCC. We discuss flaws and strength of current PD-1/PD-L1 detection, quantification methods and the evaluation of PD-L1 as a prognostic and theragnostic biomarker. Understanding tumor microenvironment may help understanding resistance to checkpoint inhibitors, designing clinical trials that can exploit drug combinations.

Selective Oral MEK1/2 Inhibitor Pimasertib: A Phase I Trial in Patients with Advanced Solid Tumors

BACKGROUND

The Ras/Raf/mitogen-activated protein kinase kinase/extracellular signal-regulated kinase (Ras/Raf/MEK/ERK) signaling cascade is frequently constitutively activated in human cancers. Pimasertib is a selective and potent adenosine triphosphate non-competitive MEK1/2 inhibitor.

OBJECTIVE

Our objectives were to describe the results of a phase I, first-in-human, dose-escalation trial of pimasertib that investigated the maximum tolerated dose, recommended phase II dose, and safety, as well as other endpoints.

PATIENTS AND METHODS

Four dosing schedules of pimasertib (once daily [qd], 5 days on, 2 days off; qd, 15 days on, 6 days off; continuous qd; continuous twice daily [bid]) were evaluated in patients with advanced solid tumors. Each treatment cycle lasted 21 days. The primary objective was to determine the maximum tolerated dose based on dose-limiting toxicities (DLTs) evaluated during cycle 1, and the recommended phase II dose (RP2D). Secondary objectives included safety, pharmacokinetics, pharmacodynamics, and antitumor activity.

RESULTS

Overall, 180 patients received pimasertib (dose range 1-255 mg/day). DLTs were mainly observed at doses ≥ 120 mg/day and included skin rash/acneiform dermatitis and ocular events, such as serous retinal detachment. The most common drug-related adverse events were consistent with class effects, including diarrhea, skin disorders, ocular disorders, asthenia/fatigue, and peripheral edema. The median time to maximum pimasertib concentration was 1.5 h across dosing schedules, and the apparent terminal half-life was 5 h across qd dosing schedules. Pimasertib decreased ERK phosphorylation within 2 h of administration, which was maintained for up to 8 h at higher doses and prolonged with bid dosing.

CONCLUSIONS

Based on the safety profile and efficacy signals, a continuous bid regimen was the preferred dosing schedule and the RP2D was defined as 60 mg bid.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT00982865.

Abstract 5103: Bidirectional EMT-dependent modulation of cancer cell and M1/M2 macrophage differentiation

Background. Head and neck (H&N) and liver carcinomas are considered as the most deadly cancers in the world. Despite advances in diagnosis and treatment, survival rates remain low mainly due to locoregional relapse, possibly triggered by the activation of epithelial to mesenchymal transition (EMT). EMT is a critical step for tumor progression, increasing motility and invasiveness of tumor cells. M1 and M2 macrophages, major components of the tumor microenvironment, were recently described as involved in EMT. Moreover, proteins expressed by cancer cells, such as CCL2 and CSF1, and promoting M2 differentiation, have been correlated with poor prognosis, and tumor aggressiveness. The aim of this study is to understand the interactions between M1/M2 macrophages and H&N or liver cancer cells considering their EMT status.

Materials and Methods. M1 and M2 macrophages were obtained from THP-1 cell after exposure to PMA followed by LPS/IFNg for M1 or IL4/IL13 for M2. Differentiation was validated by immunofluorescence (IF) using CD14 for monocyte, CD68 for macrophage, CD80 for M1, and CD163 for M2. H&N, cholangiocarcinoma (CK), and hepatocellular carcinoma (HCC) cells were characterized for their EMT status (E-cadherin/vimentin expressions) by western blot. In each tumor type, 1 epithelial and 1 mesenchymal cells were selected to analyze the effects of conditioned medium (CM) from cancer cells on macrophages differentiation, using IF. Furthermore, CCL2 and CSF1 mRNA levels were evaluated in the selected cancer cell lines. In addition, the effect of M1 and M2 CM on cancer cell proliferation, migration, and invasion were also analyzed by MTT, wound-healing, and Boyden chamber assays.

Results. Using our two steps methods, monocytes were first differentiated into macrophages (decrease of CD14 and increase of CD68 expression), and then into M1 and M2 (increase of CD80 or CD163 expression, respectively). Based on cell lines EMT status, SQ20B, SNU1196, and C3A (epithelial) and Hep2, SNU1079, and SKHep1 (mesenchymal) cells were selected. Macrophages exposed to CM from epithelial cells displayed a M1 phenotype, while macrophages exposed to CM from mesenchymal cells exhibited a M2 phenotype. Interestingly, higher mRNA expression of CCL2 and CSF1 mRNA were detected in mesenchymal cells compared to epithelial cells. In H&N and CK cell lines, M1 CM displayed increased antiproliferative effects on epithelial cells, whereas M1 CM displayed antiproliferative effects only on mesenchymal HCC cells. M1 and M2 CM increased migration and invasion in all selected cell lines, except for migration in the epithelial HCC cell line. Further characterization of M1 and M2 macrophages will be displayed at the conference.

Conclusions. This study showed that EMT status of cancer cells modulates macrophages differentiation. In fact, mesenchymal cells showed elevated levels of CCL2 and CSF1 expression, promoting M2 differentiation. Conversely, M1 and M2 displayed differential effects on H&N and liver carcinomas cell lines. These results open up new perspectives on the role of M1/M2 macrophages in EMT-dependent tumors, with the aim of developing new therapeutic approaches for patients with EMT-dependent tumors.

Citation Format: Lucile Astorgues-Xerri, Matthieu Martinet, Eric Raymond, Sandrine Faivre, Annemilaï Tijeras-Raballand. Bidirectional EMT-dependent modulation of cancer cell and M1/M2 macrophage differentiation [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5103.

Abstract 1636: Diet-variants and immune characterization of a stage-defined, transgenic immunocompetent mouse model of HCC (ASV-B)

Background: Non-alcoholic fatty liver disease (NAFLD), especially non-alcoholic steatohepatitis (NASH) is a chronic liver disease commonly associated with hepatic fibrosis. NASH patients have an increased risk for hepatocellular carcinoma (HCC). Due to western way of life, NASH incidence is rising and predicted to become the leading cause of liver transplant in 2020 and of HCC in the next decades. There is an urgent need for robust animal models fully recapitulating the NASH-related HCC carcinogenesis due to this changing in HCC etiology. In this study, we develop and characterize specific diet-induced variants from our transgenic HCC mouse model, focusing on immune landscape.

Methods: We used in the whole study ASV-B mice: a transgenic mouse model (C57BL/6J) spontaneously developing a reproducible stage-defined HCC (hyperplasia at week(W)8, nodular stage at W12, and diffuse carcinoma at W16-20). Livers were characterized for angiogenesis and immune populations using immunostaining (IHC and IF), and qRT-PCR (LightCycler, Roche). To mimic NASH, ASV-B mice were exposed to 5 different diets. Ten ASV-B and 5 control mice were fed as follows: classic diet as control (yellow), or a high-fat diet (blue), a diet enriched with saturated fatty acids + 1.25% cholesterol (green), a diet containing 22% of vegetal oil + 0.2% cholesterol (orange), and a 1.25% cholesterol diet containing 21% of milkfat (red). All mice fed with special diets also received 30% fructose in the drink water. A second experiment was performed on ASV-B and C57BL/6J wild type mice, using control and Nash-inducing regimen, to confirm our first results.

Results: ASV-B model showed an increase in liver volume and angiogenesis, HCC livers harboring marked arterialization and capillarization as compared to control. Assessing immune markers on 7 evaluable tumor specimens, we observed an increase in CD8, Foxp3, INOS, CD11b, PD-1, PD-L1, IL1β, IFN-γ, TNF-α, IL17A and IL17F mRNA expressions, as frequently observed in human inflammatory HCC. In addition, IHC staining showed intratumoral infiltration of lymphocytes (CD8+) and macrophages (F4/80+, a well-characterized and extensively referenced mouse macrophage marker). ASV-B mice receiving yellow, blue, and green regimens showed similar liver volumes and weights. By macroscopic analysis, we observed increased liver steatosis, and fibrosis in the red and orange regimen compared to others. Moreover, we observed a 40% mortality rate in the orange regimen, and a 20% mortality rate in the blue and green regimens. Interestingly, by microscopic analysis, we observed liver steatosis and inflammation, in 100%, and 75% of the mice, respectively. These results indicate that the green regimen is the most suitable to induce NASH-underlyning disease in our transgenic HCC model. At the conference, we will show in the diet-variants, the immune landscape of the livers and the results of our ongoing second experiment.

Conclusion: ASV-B transgenic mouse model mimics several characteristics of human HCC developing on healthy liver including inflammatory reaction and immune cell infiltration. In the ASV-B model, we have been able to develop specific-diets variants mimicking NASH characteristics that could be used for drug testing.

Citation Format: Annemilaï Tijeras-Raballand, Christian Hobeika, Philippe Bonnin, Benoit Rousseau, Aurélie Rodrigues, Fouad Ladfil, Marc Pocard, Armand de Gramont, Eric Raymond, Sandrine Faivre, Valérie Paradis, Clarisse Eveno. Diet-variants and immune characterization of a stage-defined, transgenic immunocompetent mouse model of HCC (ASV-B) [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1636.

Abstract 899: Remarkable anti-tumor response in a HCC transgenic mouse model treated with GNS561 in combination with anti-PD1

Introduction:Hepatocellular carcinoma (HCC) is the most frequent primary liver cancer, leading to 75,000 deaths annually. Immunotherapeutic intervention has emerged as a novel effective treatment to delay the progression of aggressive tumors and suppress tumor recurrence and metastasis. However, few clinical immunotherapy trials have been conducted in HCC patients and there is an unmet need for novel therapeutic strategies. Combinations of conventional and novel treatments with immune-oncologic agents are now regarded as a therapy that can dramatically improve the outcome of patients with HCC.GNS561 is a lysosomotropic small molecule that was investigated in the context of antitumor activity alone or in combination with a PD-1 inhibitor using a transgenic immunocompetent mouse model (ASV-B).

Materials and Methods: 40 ASV-B mice were treated with either the vehicle (p.o. water pH= 4, 5 days per week), GNS561 (p.o. 50 mg/kg/5 days per week), mouse anti-PD1 antibody (i.p. 10 mg/kg/twice a week [BIW]) or a combination of GNS561 and mouse anti-PD1 (p.o. 50 mg/kg/5 days per week and i.p. 10 mg/kg/BIW respectively) for 8 weeks. Tumor burden was evaluated by measuring the liver volume and blood flow velocity in the coeliac trunk by US/doppler 4 and 8 weeks (W8) after treatment start, the macronodules count and liver weight at sacrifice (W8). Intra and peritumoral CD8+ cells were counted.

Results: All treatments were well tolerated. No significant response was observed with the anti-PD1 monotherapy compared with the vehicle. At W8, GNS561 alone or in combination with an anti-PD-1 showed a significant rapid and durable tumor response based on the macronodule count, decreased liver blood flow in the coeliac trunk, liver volume and weight (-59% and -77%; -18% and -31%; -36% and -37%; -37% and -52%, respectively). Based on preliminary mechanistic data, GNS561 alone or in combination showed an increase in the count of CD8+ cells penetrating the tumor site compared to the vehicle and the anti-PD1 alone, suggesting GNS561 may reinstore the anti-PD1 activity by facilitating CD8+ cells to reach the tumor site to exert their antitumoral activity.

Conclusion: GNS561 alone or in combination with an anti-PD1 showed a significant antitumoral response. A combination of GNS561 with an anti-PD1 could then be of clinical interest in the treatment of hepatocelullar carcinoma.

Citation Format: Madani Rachid, Annemilaï Tijeras-Raballand, Cindy Serdjebi, Sonia Brun, Christelle Ansaldi, Eric Raymond, Philippe Halfon. Remarkable anti-tumor response in a HCC transgenic mouse model treated with GNS561 in combination with anti-PD1 [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 899.

Abstract 3684: Basal Notch1 and Notch4 activation as potential markers of aggressiveness and sensitivity to Notch inhibition in human cancer cell lines

Background. Notch pathway is involved in tumor biology including cell proliferation, migration, drug resistance, and epithelial-to-mesenchymal transition (EMT). Notch activation leads to a proteolytic cleavage, followed by the release of the Notch intracellular domain (NICD), which translocates into the nucleus and activates target genes. Notch1 and Notch4 expressions were described as mutually exclusive in some tumors, with an increased aggressiveness linked to low Notch1/high Notch4 expression phenotype. What about the role of their basal activation in cancers? The aim of this work is to characterize the role of basal Notch1 and Notch4 pathway on cell proliferation, motility and sensitivity to Notch inhibition in human pancreatic (PDAC), head&neck (H&N), colorectal (CRC), cholangio (CK), and hepato (HCC) carcinoma cell lines.

Materials and Methods. Cell lines were selected regarding their basal expression of NICD4 using western blot (one low/one high Notch4 basal activation) for each tumor type. Chosen cell lines were then characterized, by western blot and/or RT-qPCR, for Notch signaling (NICD1, HES1, NUMB), EMT status (vimentin, E-cadherin) and survival pathways (pAKT, pERK). Basal cell proliferation and motility were studied using MTT and wound-healing assay. The effects of a Notch inhibitor, PF-03084014, were assessed on cell proliferation and Notch signaling pathway by MTT and western blot.

Results. In PDAC, H&N, and CRC cell lines, high NICD4 expression was associated with low NICD1, HES1, and NUMB expressions, whereas the opposite was observed in low NICD4 expressing cells. Interestingly, all high NICD4/low NICD1 cells displayed a mesenchymal phenotype with high vimentin and low E-cadherin expressions. This phenotype was also associated with an increased proliferation rate and basal cell motility in all tumor types, except for HCC. In addition, basal ERK phosphorylation was increased in the aggressive cells (high NICD4/low NICD1). In PDAC, H&N, and CRC cell lines, PF-03084014 showed higher antiproliferative effects in high NICD4/low NICD1 cells compared to low NICD4/high NICD1 cells. In all cell lines, PF-03084014 displayed no effect on Notch4 activation, but abrogated Notch1 activation in all low NICD4/high NICD1 cells. Interestingly, PF-03084014 decreased HES1 expression in all cells, with increased effects in the most sensitive cells (high NICD4/low NICD1). Further analysis of PF-04084014 effects on cell signaling pathways will be displayed at the conference.

Conclusions. In this study, high Notch4 activation is shown to be correlated with low NICD1, HES1 and NUMB expressions. This phenotype is associated with an increased aggressiveness of human cancer cell lines, and an increased sensitivity to Notch inhibition. As expected, the strongest HES1 inhibition was observed in cell lines with an increased sensitivity to Notch inhibition. Since the inhibition of Notch pathway is an interesting topic for anticancer therapy, this study could help to select tumor types that may be good candidate for Notch inhibitors in the clinics.

Citation Format: Lucile Astorgues-Xerri, Matthieu Martinet, Eric Raymond, Annemilaï Tijeras-Raballand. Basal Notch1 and Notch4 activation as potential markers of aggressiveness and sensitivity to Notch inhibition in human cancer cell lines [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3684.

Abstract 5312: Imeglimin alone or in combination with sorafenib showed potent anti-tumor effect in human hepatocellular carcinoma: A new kid on the block for HCC treatment

Background: Diabetes as a standalone or as part of metabolic syndrome is recognized as a major risk factor in hepatocellular carcinoma (HCC). Metformin one of the most widely used first-line drug for the treatment of type II diabetes showed antitumor activity in preclinical models of HCC, and in some clinical trials. Imeglimin, a first-in-class tetrahydrotriazine oral antidiabetic agents, is currently in phase III clinical trial in diabetes with a good safety profile. Imeglimin stands as an AMPK activator and based on historical data with metformin may be a safe potentially interesting novel therapeutic drugs for patients with HCC. Hence, the current study aims to evaluate the effects of imeglimin alone or in combination with sorafenib compared to metformin in an experimental model of HCC.

Methods: All in vivo experiments were carried out with ethical committee approval and met the standards required by the UKCCCR guidelines. HepG2 HCC cells were injected subcutaneously (2 × 106cells) into the flank of female athymic nude mice. Two weeks after cell inoculation, 90% mice developed single subcutaneous palpable tumors. Mice were randomized in the groups of treatment. Mice were then treated 5 days a week by oral gavage with 75 mg/kg/day metformin (n=14-metformin75), 75 mg/kg/day imeglimin (n=14-Imeglimin75), 150 mg/kg/day imeglimin (n=14-Imeglimin150), 40 mg/kg/day sorafenib (n=14), metformin75 plus sorafenib (n=14) or imeglimin75 plus sorafenib (n=14). Body weight and tumor volumes were assessed thrice a week. Mice were sacrificed after 63 days of treatment to meet ethical requirements (tumor volume &lt; 2000 mm3). Tumor were weighted, excised and OCT-embedded to prevent tissue degradation from frozen conservation.

Results: Our experiments showed a 90% uptake in the engrafted mice. Regardless of the administrated treatment, no toxicity was observed as shown by the body weight follow-up. After 63 days of treatment, each treatment arm showed a slight difference with placebo (n=14). Mean tumor volumes were 1096±208 mm3 (P&gt;0.05), 795±222 mm3 (P&gt;0.05), 563±135 mm3 (P&lt;0.05), and 495±163 mm3(P&lt;0.05) for metformin75 alone, imeglimin75 alone, imeglimin150 alone or sorafenib alone, respectively, versus 1132±156 mm3 in the placebo group. Moreover, the combination of imeglimin75 plus sorafenib (375±121 mm3) displayed an increased antitumor activity compared to metformin75 plus sorafenib (515±112 mm3). In addition, at day 59 of treatment, we reached a tumor growth inhibition of 27%, 49%, and 66% in the imeglimin75 alone, imeglimin150 alone, and combination group imeglimin75 plus sorafenib, respectively. At the time of the meeting, we will be displayed IHC analysis in addition to assess tumor angiogenesis.

Conclusion: This study showed the antitumor effects of imeglimin, a novel AMPK activator in human HCC. Furthermore, imeglimin potentiates the antitumor effects of sorafenib, which may represent an interesting therapeutic option for patients with HCC.

Citation Format: Annemilaï Tijeras-Raballand, Matthieu Martinet, Valérie Paradis, Jean-Pierre Bizzari, Eric Janin, Eric Raymond. Imeglimin alone or in combination with sorafenib showed potent anti-tumor effect in human hepatocellular carcinoma: A new kid on the block for HCC treatment [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5312.

Impact of the COVID-19 Outbreak on the Management of Patients with Cancer

The coronavirus SARS-CoV-2 (COVID-19) outbreak is having a profound impact on the management of patients with cancer. In this review, we comprehensively investigate the various aspects of cancer care during the pandemic, taking advantage of data generated in Asia and Europe at the frontline of the COVID-19 pandemic spread. Cancer wards have been subjected to several modifications to protect patients and healthcare professionals from COVID-19 infection, while attempting to maintain cancer diagnosis, therapy, and research. In this setting, the management of COVID-19 infected patients with cancer is particularly challenging. We also discuss the direct and potential remote impacts of the global pandemic on the mortality of patients with cancer. As such, the indirect impact of the pandemic on the global economy and the potential consequences in terms of cancer mortality are discussed. As the infection is spreading worldwide, we are obtaining more knowledge on the COVID-19 pandemic consequences that are currently impacting and may continue to further challenge cancer care in several countries.

SPRING: A Worldwide Innovative Network (WIN) Consortium phase I study of triple therapy (avelumab, axitinib, and palbociclib) in advanced non-small cell lung cancer (NSCLC) with genomic and transcriptomic correlates

9581

Background: The Worldwide Innovative Network (WIN) Consortium has developed the Simplified Interventional Mapping System (SIMS) algorithm in order to predict treatment response by comparing tumor and normal tissue biopsies on both genomic and transcriptomic platforms. SPRING is the first trial to assess a SIMS-based tri-therapy regimen in advanced non-small cell lung cancer (NSCLC). Methods: Patients with advanced NSCLC (no EGFR or ALK alterations; no ROS1 alterations if tested; PD-L1 unrestricted; ≤2 prior therapy lines) were treated with avelumab, axitinib, and palbociclib (3+3 dose escalation design). Tumor and normal endobronchial mucosal biopsies were obtained on all patients for retrospective SIMS algorithm validation. Results: Fifteen patients were treated: 6 at dose level 1 (DL1); 6, dose level 2 (DL2); 3, dose level 3 (DL3). Three dose-limiting toxicities (DLTs) at least possibly drug-related occurred: 1 DLT at DL2 (Grade 3 (G3) infusion reaction); 2 patients with DLTs at DL3 (1 with G3 hand/foot syndrome and G3 fatigue and 1 with G5 respiratory failure). Among 14 evaluable patients, the partial response (PR) rate was 28.6% (4/14 patients including 2/6 patients at DL1; two PRs in patients who failed prior pembrolizumab; two PRs in patients with PD-L1 < 1%). The maximum tolerated dose was avelumab 10 mg/kg IV q2weeks, axitinib 5 mg PO BID continuous, palbociclib 75 mg PO daily on days 8-28 of a 28 day cycle (DL2). DL2 was above the recommended phase II dose (RP2D), since 5/6 patients treated at DL2 required later treatment delays and/or dose reductions, mostly due to neutropenia. To further evaluate DL1, 3 patients were added to this cohort (total of 6). Since no DLTs were seen at DL1, and 5 of 6 patients did not require dose reduction, DL1 (avelumab 10 mg/kg IV q2weeks, axitinib 3 mg PO BID continuous, palbociclib 75 mg PO daily on days 8-28 of a 28 day cycle) is the RP2D. Conclusions: The RP2D was determined to be dose level 1. This triplet showed antitumor activity in patients with NSCLC, including those progressing on prior pembrolizumab. SIMS algorithm correlates of response are being assessed. Clinical trial information: NCT03386929 .

First evaluation of neustonic microplastics in the Macaronesian region, NE Atlantic

Marine microplastic pollution is an issue of great concern nowadays since high concentrations have been detected in the ocean, mainly in the subtropical gyres that accumulate this type of debris. The long-term effects of this pollution on ecosystems and marine biota are still unknown. The aim of this study is to quantify and characterise microplastics and neustonic zooplankton in sub-surface waters of the Macaronesian region, an area that has been little studied to date. Our results show a great variability in the concentration of microplastics with values between 15,283 items/km² in Los Gigantes (Tenerife, Canary Islands) and 1,007,872 items/km² in Las Canteras (Gran Canaria, Canary Islands). The main types of debris found were plastic fragments and fibres. The abundances of neustonic zooplankton were also very variable between the different sampling areas, being the main components copepods and eggs. Regarding the microplastics-zooplankton ratio, values were obtained between 0.002 and 0.22. In Las Canteras, the highest accumulation zone, was found twice as much microplastics as zooplankton for the 1-5 mm fraction in dry weight. These values highlight the potential hazard of microplastics - and its associated chemical contaminants - for marine biota, especially for large filter feeders.

Biomarkers and overall survival in patients with advanced hepatocellular carcinoma treated with TGF-βRI inhibitor galunisertib

Background

Transforming growth factor beta (TGF-β) signalling is involved in the development of hepatocellular carcinoma (HCC). We followed changes in biomarkers during treatment of patients with HCC with the TGF-βRI/ALK5 inhibitor galunisertib.

Methods

This phase 2 study (NCT01246986) enrolled second-line patients with advanced HCC into one of two cohorts of baseline serum alpha-fetoprotein (AFP): Part A (AFP ≥1.5x ULN) or Part B (AFP <1.5x ULN). Baseline and postbaseline levels of AFP, TGF-β1, E-cadherin, selected miRNAs, and other plasma proteins were monitored.

Results

The study enrolled 149 patients (Part A, 109; Part B, 40). Median OS was 7.3 months in Part A and 16.8 months in Part B. Baseline AFP, TGF-β1, E-cadherin, and an additional 16 plasma proteins (such as M-CSF, IL-6, ErbB3, ANG-2, neuropilin-1, MIP-3 alpha, KIM-1, uPA, IL-8, TIMP-1, ICAM-1, Apo A-1, CA-125, osteopontin, tetranectin, and IGFBP-1) were found to correlate with OS. In addition, a range of miRs were found to be associated with OS. In AFP responders (21% of patients in Part A with decrease of >20% from baseline) versus non-responders, median OS was 21.5 months versus 6.8 months (p = 0.0015). In TGF-β1 responders (51% of all patients) versus non-responders, median OS was 11.2 months versus 5.3 months (p = 0.0036).

Conclusions

Consistent with previous findings, both baseline levels and changes from baseline of circulating AFP and TGF-β1 function as prognostic indicators of survival. Future trials are needed to confirm and extend these results.

Tislelizumab plus chemotherapy as first-line treatment for unresectable, locally advanced recurrent/metastatic esophageal squamous cell carcinoma

TPS462

Background: Esophageal squamous cell carcinoma (ESCC) is the predominant histological subtype of esophageal cancer, particularly in Asian countries. Inhibition of the PD-1/PD-L1 axis has demonstrated antitumor activity in patients with advanced unresectable or metastatic ESCC. Tislelizumab, an investigational humanized IgG4 monoclonal antibody with high affinity and binding specificity for PD-1, was engineered to minimize binding to FcγR on macrophages in order to abrogate antibody-dependent phagocytosis, a mechanism of T-cell clearance and potential resistance to anti-PD-1 therapy. Results from early phase clinical studies suggest tislelizumab, as a single agent or in combination with chemotherapy, was generally well tolerated and had antitumor activity in patients with solid tumors, including ESCC. Methods: This global, phase 3, randomized, placebo-controlled, double-blind study (NCT03783442) is designed to evaluate the efficacy and safety of tislelizumab plus chemotherapy as first-line treatment of unresectable, locally advanced recurrent or metastatic ESCC. Adult patients with histologically confirmed unresectable ESCC, or locally advanced recurrent/metastatic disease with a ≥6 month treatment-free interval, are eligible; palliative radiation administered > 4 weeks from study initiation is allowed. Patients who received prior anti-PD-(L)1, anti-PD-L2, or first-line therapy are ineligible. Patients (n≈480) will be randomized 1:1 to receive tislelizumab 200 mg IV every 3 weeks (Q3W) plus investigator-chosen chemotherapy (ICC) or placebo plus ICC. ICC options include: platinum (plat; cisplatin 60-80 mg/m2 or oxaliplatin 130 mg/m2 IV Q3W) + 5-FU 750-800 mg/m2 by continuous IV infusion over 24 hours for 5d Q3W; or plat + capecitabine 1000 mg/m2 orally BID for 14d Q3W; or plat + paclitaxel 175 mg/m2 IV Q3W. Progression-free and overall survival are primary endpoints; secondary endpoints include objective response rate, duration of response, and health-related quality of life. Safety will be assessed by monitoring adverse events, physical examinations, vital signs, and electrocardiograms. This study is actively enrolling. Clinical trial information: NCT03783442.

Prohibitin (PHB) expression is associated with aggressiveness in DLBCL and flavagline-mediated inhibition of cytoplasmic PHB functions induces anti-tumor effects

BACKGROUND

Diffuse large B-cell lymphomas (DLBCLs) are aggressive lymphomas accounting for approximately a third of non-Hodgkin lymphomas. Prohibitin 1 (PHB1) and prohibitin 2 (PHB2) are scaffold proteins that promote mitochondria homeostasis and consequently cell survival, but biological functions of cytoplasmic PHBs remain largely unknown in DLBCL.

METHODS

PHB expression was analyzed in 82 DLBCL biopsies and five DLBCL cell lines by immunohistochemistry (IHC) and Western blotting. Pharmacological inhibition of PHB using the synthetic flavagline FL3 was realized in vitro to gain insight PHB cellular functions. Effects of FL3 on DLBCL cell line viability, apoptosis, C-Raf-ERK-MNK-eIF4E signaling pathway and eIF4F complex formation and activity were evaluated by XTT assay, annexin V-FITC/PI dual staining and Western blotting respectively. Subcutaneous DLBCL xenograft model in SCID mice was also performed to determine in vivo FL3 effect.

RESULTS

As in DLBCL cell lines, PHB1 and PHB2 were expressed in germinal center B-cell-like (GCB) and activated B-cell-like (ABC) subtypes. In patient samples, high PHB levels were associated with higher serum LDH (PHB1 and PHB2), IPIaa (PHB2), and Ki-67 (PHB2) expression. Higher PHB1 expression tends to be associated with shorter event-free survival (EFS) in patients, especially in male patients. FL3 induced apoptosis of DLBCL cell lines that was associated with inhibition of the ERK-MNK-eIF4E signaling pathway, including aggressive double/triple-hit DLBCL cell lines. This resulted in altered eIF4F complex formation and activity leading to a reduction of Bcl-2 and c-Myc expression levels. Moreover, FL3 strongly downregulated DLBCL cellular levels of Akt protein and AKT mRNA. FL3 antitumor activity was also confirmed in vivo in a murine xenograft model.

CONCLUSION

Our data indicate that PHB overexpression is associated with markers of tumor aggressiveness in DLBCL, and that targeting PHBs may be a therapeutic option, notably in aggressive subtypes.

Novel transforming growth factor beta receptor I kinase inhibitor galunisertib (LY2157299) in advanced hepatocellular carcinoma

BACKGROUND AND AIMS

We assessed the activity of galunisertib, a small molecule inhibitor of the transforming growth factor beta (TGF-β1) receptor I, in second-line patients with hepatocellular carcinoma (HCC) in two cohorts of baseline serum alpha fetoprotein (AFP).

METHODS

Patients with advanced HCC who progressed on or were ineligible to receive sorafenib, Child-Pugh A/B7 and ECOG PS ≤1 were enrolled into Part A (AFP ≥ 1.5× ULN) or Part B (AFP < 1.5× ULN). Patients were treated with 80 or 150 mg galunisertib BID for 14 days per 28-day cycle. Endpoints were time-to-progression (TTP) and changes in circulating AFP and TGF-β1 levels, as well as safety, pharmacokinetics, progression-free survival and overall survival (OS).

RESULTS

Patients (n = 149) were enrolled with median age 65 years. Median TTP was 2.7 months (95% CI: 1.5-2.9) in Part A (n = 109) and 4.2 months (95% CI: 1.7-5.5) in Part B (n = 40). Median OS was 7.3 months (95% CI: 4.9-10.5) in Part A and 16.8 months (95% CI: 10.5-24.4) in Part B. OS was longer in AFP responders (>20% decrease from baseline, Part A) compared to non-responders (21.5 months vs 6.8 months). OS was longer in TGF-β1 responders (>20% decrease from baseline, all patients) compared to non-responders. The most common Grade 3/4 treatment-related adverse events were neutropenia (n = 4) and fatigue, anaemia, increased bilirubin, hypoalbuminemia and embolism (each, n = 2).

CONCLUSIONS

Galunisertib treatment had a manageable safety profile in patients with HCC. Lower baseline AFP and a response in AFP or TGF-β1 levels (vs no response) correlated with longer survival.

TRIAL REGISTRATION NUMBER

NCT01246986 at ClinicalTrials.gov.

Abstract 1080: Link between M1/M2 human macrophages and epithelial-mesenchymal status in head and neck cancer cell lines

Background. Head and neck carcinoma (H&N) is one of the leading causes of cancer deaths worldwide. Despite advances in diagnosis and treatment, the survival rates remain low mainly due to locoregional relapse, possibly triggered by the activation of epithelial-to-mesenchymal transition (EMT). Recently, several studies have demonstrated a positive link between macrophages, EMT and invasion in H&N cancer. The aim of this study is to analyze the interactions between human antitumoral M1/protumoral M2 macrophages and H&N human cancer cells with different EMT status, with the aim of developing new therapeutic approaches for H&N cancer patients.

Materials and Methods. M1 and M2 macrophages were obtained from THP-1 cell line (human monocyte) after 48h exposure to 25nM of PMA followed by 48h of recovery culture medium, and 72h exposure to 1ng/ml LPS + 20ng/ml IFNγ to obtain M1 phenotype or 20ng/ml IL4 + 20ng/ml IL13 to obtain M2 phenotype. Differentiation status was validated by immunofluorescence (IF) using CD14 for monocyte, CD68 for macrophage, CD80 for M1, and CD163 for M2. Eight H&N cell lines were characterized for their EMT status (E-cadherin/vimentin expression) by western blot. SQ20B (epithelial) and Hep2 (mesenchymal) cell lines were selected to study the effect of M1 and M2 conditioned medium (CM) on cell proliferation. In addition, we also analyzed the effects of CM from SQ20B and Hep2 on macrophages differentiation using IF.

Results. We confirmed the differentiation of monocytes into macrophages by a decrease of CD14 expression and an increase of CD68 expression, and the differentiation of macrophages into M1 and M2 by an increase of CD80 and CD163 expression, respectively. Among the 8 H&N cell lines, 3 cell lines showed an epithelial status (high E-cadherin expression), one a mesenchymal status (high vimentin expression), and 4 a mixed status. Based on these results, we exposed SQ20B (epithelial) and Hep2 (mesenchymal) to M1 or M2 CM. M1 CM strongly inhibited the proliferation of SQ20B cells, with moderate effect on Hep2 cells, whereas M2 CM displayed no effect on SQ20B cells and slightly increased the proliferation of Hep2 cells. Moreover, macrophages exposed to SQ20B CM displayed a M1 phenotype with an increased expression of CD80, whereas Hep2 CM induced a M2 phenotype with an increased expression of CD163.

Conclusions. In vitro, we showed that M1 and M2 macrophages displayed opposite effects on H&N cancer cells proliferation via their conditioned medium, M1 being anti-proliferative and M2 pro-proliferative. These effects were dependent on epithelial/mesenchymal status of cancer cells. In addition, we showed that factors secreted by epithelial vs mesenchymal cancer cells induced macrophages differentiation into M1 and M2, respectively. These results open up new perspectives on the role of M1/M2 macrophages in EMT-dependent H&N cancers and other tumor types such as colon, lung, and liver carcinoma.

Citation Format: Lucile Astorgues-Xerri, Diane Evrard, Matthieu Martinet, Eric Raymond, Sandrine Faivre, Annemilaï Tijeras-Raballand. Link between M1/M2 human macrophages and epithelial-mesenchymal status in head and neck cancer cell lines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1080.

Abstract 859: Basal Notch4 activation is a druggable marker of aggressiveness in a panel of human cancer cell lines

Background: Notch pathway has been involved in cell differentiation, proliferation, apoptosis, angiogenesis and drug resistance, as well as in epithelial-to-mesenchymal transition. Notch pathway activation leads to a proteolytic cleavage, releasing the Notch intracellular domain (NICD), which translocates to the nucleus and activates target genes, such as HES1 (interacting with Notch for maintenance of stem cells and progenitor phenotype). Our team has demonstrated the involvement of PlGF/VEGFR1/Notch4 axis in the angiogenesis of hepatocellular carcinoma, but what about the role of Notch in other cancer types? The aim of this work is to characterize the basal activation and the role of Notch4 in a panel of human cancer cell lines.

Materials and Methods: We characterized a panel of 8 pancreatic (PDAC), 8 head and neck (H&N), 5 colorectal (CRC), 5 cholangiocarcinoma (CK), and 10 hepatocellular (HCC) human carcinoma cell lines for intracellular domain of the notch protein 4 (NICD4), HES1, E-cadherin, and Vimentin expression by Western Blot. In each tumor type, cell lines with high and low Notch4 activation were selected to assess basal cell proliferation and migration, using MTT and wound-healing assay, respectively. In high versus low Notch4 cell lines, we assessed NUMB expression (involved in NICD proteasomal degradation) and the effect of a Notch inhibitor, PF- 03084014.

Results: Notch4 activation assessed by NICD4 expression was observed in 6 out of 8 (6/8) PDAC, 7/8 H&N, 2/5 CRC, 4/5 CK, and 5/10 HCC cell lines. In PDAC cells, Notch4 activation was correlated with high Vimentin expression. In PDAC-, H&N-, CRC-, and CK-low NICD4 cells, we observed an overexpression of NUMB, suggesting a correlation between low Notch4 activation and proteasomal degradation. In most tumor types, Notch4 activation was associated with an increased proliferation rate and basal migration. PF-03084014 had pronounced antiproliferative effects in high NICD4 cells in comparison to low NICD4 cells, except for HCC. In H&N cells, PF-03084014 displayed no effect on Notch4 activation. We also observed a decrease in HES1 expression (significant in high NICD4 cells) and an increased in AKT phosphorylation (significant in low NICD4 cells). We will further analyze the effect of PF-03084014 on cell signaling and migration in other tumor types to display the results at the conference.

Conclusions: In this study, we demonstrated a correlation between high Notch4 basal activation and increased proliferation/migration in a panel of human cancer cell lines, as well as higher sensitivity to the Notch inhibitor PF-03084014. In highly sensitive H&N cell lines, PF-03084014 inhibited Notch signaling pathway, whereas we observed an activation of AKT survival pathway in the low-sensitive ones. Since Notch inhibition is an interesting topic for antitumor therapy, this study could help to select tumor types that could be good candidate for Notch inhibition in the clinic.

Citation Format: Lucile Astorgues-Xerri, Matthieu Martinet, Eric Raymond, Sandrine Faivre, Annemilaï Tijeras-Raballand. Basal Notch4 activation is a druggable marker of aggressiveness in a panel of human cancer cell lines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 859.