Search

Background Antibody-dependent cell-mediated cytotoxicity (ADCC) may mediate antitumour activity of IgG1-isotype monoclonal antibody (mAb), suggesting as potential treatment combination of IgG1-mAbs, anti-epidermal growth factor receptor cetuximab and anti-programmed death-ligand-1 avelumab. Methods We evaluated ADCC induction in lung cancer cells by lactate dehydrogenase (LDH) release assay. Antitumour activity and safety of cetuximab plus avelumab were explored in a single-arm proof-of-concept study in pre-treated non-small cell lung cancer (NSCLC) patients (pt) (Cetuximab-AVElumab-lung, CAVE-Lung). Search for predictive biomarkers of response was done. Results Avelumab plus cetuximab induced ADCC in NSCLC cells in vitro in presence of natural killers (NK) from healthy donors (HD) or NSCLC pt, as effectors. Sixteen relapsed NSCLC pt were treated with avelumab plus cetuximab. Antitumour activity was observed in 6/16 pt, defined by progression free survival (PFS) ≥8 months, with 4 of them still on treatment at data lock time (range, 14–19 months). Of note, 3/6 responders had received as previous line anti-programmed death-1 therapy. In responders, clinical benefit was accompanied by significant increase in LDH release over baseline at the first radiological evaluation (8 weeks) (p=0.01) and by early skin toxicity; while in the 10 non-responders, that had PFS ≤5 months, LDH release tends to reduce. Baseline circulating DNA levels were higher in non-responders compared with responders and HD (p=0.026) and decrease in responders during therapy. Mutations in DNA damage responsive family genes were found in responders. Conclusion Cetuximab and avelumab activates NSCLC pt NK cells. Ex vivo evaluation of ADCC, circulating DNA levels and early skin toxicity may predict response to cetuximab plus avelumab in NSCLC. EUDRACT 2017-004195-58

Background AXL and transforming growth factor β (TGF-β) signalling pathways play a key role in modulating tumour microenvironment by promoting epithelial to mesenchymal transition (EMT), stromal activation and regulating immune response in colorectal cancer (CRC). Here we have evaluated the effect of double blockade of TGF-β and AXL receptors, as an innovative therapeutic strategy for CRC. Methods We assessed the correlation of TGF-β and AXL by an in silico analysis of a human CRC gene expression profile database. Afterwards, an evaluation of AXL expression of in a panel of human CRC cell lines by Western Blot (WB) and Real time PCR was performed. The sensitivity of HCT116 and LOVO cells to treatment with galunisertib (LY21209761), a TGF-β R1 inhibitor, and R428, an AXL inhibitor, was assessed by MTT, cell migration, and colony forming assays. Furthermore we generated patient derived 3D spheroid cultures from primary CRC, and tested their susceptibility to galunisertib and R428 by MTT assay. Finally, in vivo experiments were done with HCT116 and LOVO tumour xenografts in immunodeficient mice. Results In silico analysis showed an association between high expression levels of AXL and TGF-β R1 in CMS4 CRC. AXL was differently expressed on cell lines, and interestingly it resulted increased in HCT116 and LOVO after TGF-β inhibition, probably representing a mechanism of cancer cell escape. Dual blockade with galunisertib and R428 determined a reduction in cell migration of 50% in HCT116 and 37% in LOVO cells, respectively, and colony formation of approximately 90 % in both cell lines. Moreover, combined treatment displayed a strong synergistic activity in 3D cultures derived from five human CRC samples, resulting in the inhibition of proliferation ranging from 80 to 90%. The in vivo experiments of HCT116 and LOVO subcutaneous xenograft models are currently on going and results will be presented. Conclusions Combined TGF-β and AXL inhibition showed a promising activity in preclinical models of CRC and could represent a novel potential therapeutic strategy for patients with CRC. Legal entity responsible for the study Universita degli studi della Campania "Luigi Vanvitelli". Funding ICURE project, Universita degli studi della Campania "Luigi Vanvitelli". Disclosure D. Melisi: Research grant/Funding (self): Lilly.

Background Previous studies have demonstrated that IgG1 mAbs as cetuximab, stimulate Antibody-Dependent Cell Cytotoxicity (ADCC). Among immune checkpoint inhibitors, avelumab is the only fully human IgG1 anti-PD-L1 mAb with ADCC properties. Anti-PD-L1 and anti-EGFR mediated NK cytotoxicity is evaluated. Methods LDH release was analyzed to study NK-mediated cytotoxicity by LDH Cytotoxicity Assay Kit and results was correlated to the level of PD-L1, EGFR and MHC-I cell surface expression analyzed by flow cytometry. NK-mediated cytotoxicity of the combination of anti-PD-L1 and anti-EGFR mAbs was studied in a panel of NSCLC cells lines encompassing different tumor types, using as effector NK cells isolated from healthy donors or NSCLC patients. Results PD-L1/EGFR/MHC-I expression levels correlated with enhanced ADCC lysis by the combination of avelumab and cetuximab as demonstrated by LDH assay, CD16 and CD107a mRNA. No significant difference in avelumab plus cetuximab-mediated ADCC between NK cells from healthy donors or from NSCLC patients was observed with a trend in favor of cancer patients, indicating that NK from cancer patients maintain lytic activity. ADCC capability of NK cells isolated from patients enrolled in the phase II study CAVE (Cetuximab-AVElumab)-lung, a single arm phase II clinical study of the combination of avelumab plus cetuximab in the second line treatment of metastatic non small cell lung cancer (NSCLC) patients (EUDRACT 2017- 004195-58) study resulted significantly enhanced after the experimental treatment compared to untreated baseline and healthy donors samples. Conclusions The combination of anti-EGFR and anti PD-L1 IgG1 antibodies is synergistic in terms of ADCC, where each antibody complements each other by promoting a more permissive immune reaction against the tumor, active also in otherwise immune-resistant cancers. Legal entity responsible for the study Universita degli studi della Campania Luigi Vanvitelli. Funding Merck KGaA. Disclosure F. Ciardiello: Advisory / Consultancy, Research grant / Funding (institution): Roche; Advisory / Consultancy, Research grant / Funding (institution): Bayer; Advisory / Consultancy, Research grant / Funding (institution): Amgen; Advisory / Consultancy: Merck; Advisory / Consultancy: Pfizer; Advisory / Consultancy: Sanofi; Advisory / Consultancy: Servier; Advisory / Consultancy: BMS; Advisory / Consultancy: Cellgene; Advisory / Consultancy: Lilly; Research grant / Funding (institution): AstraZeneca; Research grant / Funding (institution): Ipsen. F. Morgillo: Advisory / Consultancy: MSD; Advisory / Consultancy: Lilly; Research grant / Funding (institution): AstraZeneca. All other authors have declared no conflicts of interest.

Background Molecular mechanisms driving acquired resistance to anti-EGFR therapies in metastatic Colorectal Cancer (mCRC) are complex but generally involve the activation of the downstream RAS-RAF-MEK-MAPK pathway. Methods In order to understand the mechanism underlying MEK inhibitor (MEKi) resistance, we generated three different MEKi resistant models, two all RAS WT (SW48-MR and LIM1215-MR) and one mutated in RAS (HCT116-MR). Results These models showed features related to the gene signature of Colorectal Cancer CMS4 with upregulation of immune pathway as confirmed by Microarray and Western blot analysis. In particular, moving forward the MEKi phenotype we assisted to the loss of epithelial features and acquisition of mesenchymal markers and morphology. Moreover, this change in the morphology is accompanied by up-regulation of PD-L1 expression and activation of EGFR and its downstream pathway, independently of cell line status mutation. To extend these in vitro findings, we performed an in vivo study using MC38 and CT26 MEKi resistant syngeneic models that we have previously generated. Combined treatment of MEKi, EGFR inhibitor (EGFRi) and PD-L1inhibitor (PD-L1i) resulted in a marked inhibition of tumor growth in both MC38–MR and CT26-MR xenograft model. Conclusions These results suggest a strategy to potentially overcome immunotherapy resistance in CMS4-like tumors and to improve the efficacy of MEK inhibition by co-treatment with other agents providing an additional therapeutic strategy via modulation of host immune responses. Legal entity responsible for the study The authors. Funding Has not received any funding. Disclosure All authors have declared no conflicts of interest.

Background In the era of precision medicine, cancer treatment strategies are aimed to be patient-tailored. Here, we report a translational study conducted on a NSCLC patient where the potentiality of ex vivo spheroidal cultures and peripheral blood biomarkers were investigated to analyze correspondence with treatment response. Methods We developed a protocol to generate ex vivo spheroidal cultures from patient’s surgical sample that has been used to assess drug sensitivity through cell proliferation MTT assay. Primary tumor tissue, patient-derived spheroids and patient’s circulating tumor DNA (ctDNA) were characterized through immunohistochemistry (IHC), immunofluorescence and next generation sequencing (NSG) analysis. Tumor infiltrating lymphocytes (TILs) from surgical specimen were analyzed by FACS and the analysis of TCR repertoire was conducted using Spectratyping technique. Moreover, peripheral blood samples collected at different time points underwent qPCR analysis to assess cytokines expression and flow cytometry to study peripheral blood mononuclear cells (PBMCs). All these data were correlated with clinical and radiological evaluations. Results Immunohistochemistry, immunofluorescence, NGS analysis and TCR repertoire assay showed elevated concordance among primary tumor tissue, spheroids and ctDNA. Cisplatin-based chemotherapy and anti-PD-1 treatment sensitivity assessed in spheroidal cultures allowed us to anticipate patient response to chemo- and immunotherapy. Furthermore, circulating cytokines expression levels and lymphocytes subpopulations profiling correlated with clinical and radiological response to first line anti-PD-1 therapy. Conclusions This approach demonstrated the feasibility of using spheroidal cultures, cytokines expression levels and PBMCs profiling to follow patient’s disease history and response to treatment in parallel with clinical and radiological evaluation. Legal entity responsible for the study Universita degli Studi della Campania Luigi Vanvitelli. Funding Has not received any funding. Disclosure F. Ciardiello: Advisory / Consultancy, Research grant / Funding (institution): Roche; Advisory / Consultancy, Research grant / Funding (institution): Bayer; Advisory / Consultancy, Research grant / Funding (institution): Amgen; Advisory / Consultancy: Merck; Advisory / Consultancy: Pfizer; Advisory / Consultancy: Sanofi; Advisory / Consultancy: Servier; Advisory / Consultancy: BMS; Advisory / Consultancy: Cellgene; Advisory / Consultancy: Lilly; Research grant / Funding (institution): AstraZeneca; Research grant / Funding (institution): Ipsen. F. Morgillo: Advisory / Consultancy: MSD; Advisory / Consultancy: Lilly; Research grant / Funding (institution): AstraZeneca. All other authors have declared no conflicts of interest.

Background Anti-PD-1 antibodies represent nowadays a first-choice therapy for metastatic melanoma patients. Despite impressive results in terms of PFS and OS, a proportion of patients does not respond to anti-PD-1 therapy with an overall poor prognosis. Identification of predictive biomarkers is considered an important unmet clinical need to avoid expensive and potentially harmful drugs in patients who will not respond to them. In the last years, many studies have evaluated the role of cytokines on both blood and tissue samples as predictive biomarkers for immunotherapy, with encouraging results. Methods Blood samples from 18 patients with metastatic melanoma treated with anti-PD-1 antibodies as first line therapy were collected at baseline. 8 patients were classified as non-responders (best response: PD excluding pseudo-progression with median PFS of 2 months) and 10 patients as responders (best response: PR or CR, with median PFS of 17 months). mRNA expression levels of the main pro- and anti-inflammatory cytokines were evaluated by Real time quantitative PCR in PBMCs obtained from baseline blood samples. Unpaired two-tailed t-test was used for statistical analysis. Results IFN-γ mRNA expression levels were higher in responder patients (p 0.05). Combining data for each patient, we noticed a correlation between higher levels of IFN-γ and lower levels of IL-10 for responders and vice versa. Starting from these findings, we observed that the IFN-γ/IL-10 ratio was higher (median: 43,3 vs 5,2) in responders (p Conclusions Our data suggest an interesting correlation between IFN-γ/IL-10 ratio and response to anti-PD-1 therapy in melanoma patients. This correlation seems to be stronger than using IFN-γ expression levels alone probably because of the influence of anti-inflammatory cytokines. Since this is an exploratory and retrospective analysis of 18 patients, a larger population should be tested to validate our results. Legal entity responsible for the study Dipartimento di Medicina di Precisione, Universita degli studi della Campania Luigi Vanvitelli. Funding Has not received any funding. Disclosure F. Ciardiello: Advisory / Consultancy: Roche; Advisory / Consultancy: Amgen; Advisory / Consultancy: Merck; Advisory / Consultancy: Sanofi; Advisory / Consultancy: Bayer; Advisory / Consultancy: Pfizer; Advisory / Consultancy: Servier; Advisory / Consultancy: BMS; Advisory / Consultancy: Cellgene; Advisory / Consultancy: Lilly; Research grant / Funding (institution): Bayer; Research grant / Funding (institution): Roche; Research grant / Funding (institution): Merck; Research grant / Funding (institution): AstraZeneca; Research grant / Funding (institution): Amgen; Research grant / Funding (institution): Takeda. T. Troiani: Research grant / Funding (institution): Roche; Research grant / Funding (institution): Sanofi; Research grant / Funding (institution): Merck; Research grant / Funding (institution): Amgen; Research grant / Funding (institution): Servier; Research grant / Funding (institution): Novartis; Research grant / Funding (institution): Bayer. All other authors have declared no conflicts of interest.