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Mesothelin antigen density influences anti-mesothelin chimeric antigen receptor T cell cytotoxicity.Cytotherapy Apr 2024Several anti-mesothelin (MSLN) chimeric antigen receptor (CAR) T cells are in phase 1/2 clinical trials to treat solid-organ malignancies. The effect of MSLN antigen...
BACKGROUND AIMS
Several anti-mesothelin (MSLN) chimeric antigen receptor (CAR) T cells are in phase 1/2 clinical trials to treat solid-organ malignancies. The effect of MSLN antigen density on MSLN CAR cytotoxicity against tumor cells has not been examined previously, nor are there data regarding the effect of agents that increase MSLN antigen density on anti-MSLN CAR T cell efficacy.
METHODS
MSLN antigen density was measured on a panel of pancreatic cancer and mesothelioma cell lines by flow cytometry. In parallel, the cytotoxicity and specificity of two anti-MSLN CAR T cells (m912 and SS1) were compared against these cell lines using a real-time impedance-based assay. The effect of two MSLN 'sheddase' inhibitors (lanabecestat and TMI-1) that increase MSLN surface expression was also tested in combination with CAR T cells.
RESULTS
SS1 CAR T cells were more cytotoxic compared with m912 CAR T cells against cell lines that expressed fewer than ∼170 000 MSLN molecules/cell. A comparison of the m912 and amatuximab (humanized SS1) antibodies identified that amatuximab could detect and bind to lower levels of MSLN on pancreatic cancer and mesothelioma cell lines, suggesting that superior antibody/scFv affinity was the reason for the SS1 CAR's superior cytotoxicity. The cytotoxicity of m912 CAR T cells was improved in the presence of sheddase inhibitors, which increased MSLN antigen density.
CONCLUSIONS
These data highlight the value of assessing CAR constructs against a panel of cells expressing varying degrees of target tumor antigen as occurs in human tumors. Furthermore, the problem of low antigen density may be overcome by concomitant administration of drugs that inhibit enzymatic shedding of MSLN.
Topics: Humans; Cell Line, Tumor; Immunotherapy, Adoptive; Mesothelin; Mesothelioma; Pancreatic Neoplasms; Receptors, Chimeric Antigen; T-Lymphocytes
PubMed: 38349311
DOI: 10.1016/j.jcyt.2024.01.011 -
Frontiers in Immunology 2023Mesothelin (MSLN) is overexpressed in a wide variety of cancers with few therapeutic options and has recently emerged as an attractive target for cancer therapy, with a...
INTRODUCTION
Mesothelin (MSLN) is overexpressed in a wide variety of cancers with few therapeutic options and has recently emerged as an attractive target for cancer therapy, with a large number of approaches currently under preclinical and clinical investigation. In this respect, developing mesothelin specific tracers as molecular companion tools for predicting patient eligibility, monitoring then response to mesothelin-targeting therapies, and tracking the evolution of the disease or for real-time visualisation of tumours during surgery is of growing importance.
METHODS
We generated by phage display a nanobody (Nb S1) and used enzymatic approaches were used to site-directed conjugate Nb S1 with either ATTO 647N fluorochrome or NODAGA chelator for fluorescence and positron emission tomography imaging (PET) respectively.
RESULTS
We demonstrated that Nb S1 displays a high apparent affinity and specificity for human mesothelin and demonstrated that the binding, although located in the membrane distal domain of mesothelin, is not impeded by the presence of MUC16, the only known ligand of mesothelin, nor by the therapeutic antibody amatuximab. experiments showed that both ATTO 647N and [Ga]Ga-NODAGA-S1 rapidly and specifically accumulated in mesothelin positive tumours compared to mesothelin negative tumours or irrelevant Nb with a high tumour/background ratio. The biodistribution profile analysis also confirmed a significantly higher uptake of Nb S1 in MSLN-positive tumours than in MSLN tumours.
CONCLUSION
We demonstrated for the first time the use of an anti-MSLN nanobody as PET radiotracer for same day imaging of MSLN tumours, targeting an epitope compatible with the monitoring of amatuximab-based therapies and current SS1-derived-drug conjugates.
Topics: Humans; Mesothelin; Tissue Distribution; Positron-Emission Tomography; Neoplasms; Antibodies, Blocking
PubMed: 37388728
DOI: 10.3389/fimmu.2023.1200652 -
Cancers Nov 2021Advances in the treatment of pediatric AML have been modest over the past four decades. Despite maximally intensive therapy, approximately 40% of patients will relapse....
Advances in the treatment of pediatric AML have been modest over the past four decades. Despite maximally intensive therapy, approximately 40% of patients will relapse. Novel targeted therapies are needed to improve outcomes. We identified mesothelin (MSLN), a well-validated target overexpressed in some adult malignancies, to be highly expressed on the leukemic cell surface in a subset of pediatric AML patients. The lack of expression on normal bone marrow cells makes MSLN a viable target for immunotherapies such as T-cell engaging bispecific antibodies (BsAbs) that combine two distinct antibody-variable regions into a single molecule targeting a cancer-specific antigen and the T-cell co-receptor CD3. Using antibody single-chain variable region (scFv) sequences derived from amatuximab-recognizing MSLN, and from either blinatumomab or AMG330 targeting CD3, we engineered and expressed two MSLN/CD3-targeting BsAbs: MSLN-CD3 and MSLN-CD3, respectively. Both BsAbs promoted T-cell activation and reduced leukemic burden in MV4;11:MSLN xenografted mice, but not in those transplanted with MSLN-negative parental MV4;11 cells. MSLN-CD3 induced complete remission in NTPL-146 and DF-5 patient-derived xenograft models. These data validate the in vivo efficacy and specificity of MSLN-targeting BsAbs. Because prior MSLN-directed therapies appeared safe in humans, MSLN-targeting BsAbs could be ideal immunotherapies for MSLN-positive pediatric AML patients.
PubMed: 34885074
DOI: 10.3390/cancers13235964 -
Investigational New Drugs Oct 2021Amatuximab is a promising therapeutic antibody targeting mesothelin, a 40-kDa glycoprotein that is highly expressed in pancreatic cancer. We investigated the...
Early administration of amatuximab, a chimeric high-affinity anti-mesothelin monoclonal antibody, suppresses liver metastasis of mesothelin-expressing pancreatic cancer cells and enhances gemcitabine sensitivity in a xenograft mouse model.
Amatuximab is a promising therapeutic antibody targeting mesothelin, a 40-kDa glycoprotein that is highly expressed in pancreatic cancer. We investigated the effectiveness of early amatuximab treatment, imitating an adjuvant chemotherapy setting, and combination therapy with amatuximab and gemcitabine in liver metastasis of pancreatic cancer. Liver metastasis mouse models were established in 8-week-old male BALB/c nu/nu mice using the hemisplenic injection method. Tridaily amatuximab monotherapy or combination with gemcitabine was administered to the liver metastasis mouse model before metastatic lesions had formed huge masses. Gaussia luciferase-transfected AsPC-1 was used as a mesothelin-overexpressing pancreatic cancer cell line. The amount of liver metastases and the serum luciferase activity were significantly lower in the treatment groups than those in the control IgG group. Notably, the anti-tumor activity of gemcitabine was synergically enhanced by combination therapy with amatuximab. Furthermore, western blotting revealed that the high expression of phosphorylated c-Met and AKT in liver metastatic lesions treated with gemcitabine monotherapy was canceled by its combination with amatuximab. This result indicated that the observed synergic therapeutic effect may have occurred as a result of the inhibitory effect of amatuximab on the phosphorylation of c-Met and AKT, which were promoted by exposure to GEM. In conclusion, our study revealed that early administration of amatuximab alone or in combination with GEM significantly suppressed the liver metastases of mesothelin-expressing pancreatic cancer cells. A phase II clinical trial of amatuximab as part of an adjuvant chemotherapy regimen for resected pancreatic cancer is expected.
Topics: Animals; Antibodies, Monoclonal; Antineoplastic Agents; Deoxycytidine; Drug Synergism; Liver Neoplasms; Male; Mesothelin; Mice; Mice, Inbred BALB C; Mice, Nude; Pancreatic Neoplasms; Xenograft Model Antitumor Assays; Gemcitabine
PubMed: 33905019
DOI: 10.1007/s10637-021-01118-1 -
BMC Cancer Feb 2021Mesothelin is a 40-kDa glycoprotein that is highly overexpressed in various types of cancers, however molecular mechanism of mesothelin has not been well-known.... (Comparative Study)
Comparative Study
Mesothelin blockage by Amatuximab suppresses cell invasiveness, enhances gemcitabine sensitivity and regulates cancer cell stemness in mesothelin-positive pancreatic cancer cells.
BACKGROUND
Mesothelin is a 40-kDa glycoprotein that is highly overexpressed in various types of cancers, however molecular mechanism of mesothelin has not been well-known. Amatuximab is a chimeric monoclonal IgG1/k antibody targeting mesothelin. We recently demonstrated that the combine therapy of Amatuximab and gemcitabine was effective for peritonitis of pancreatic cancer in mouse model.
METHODS
We discover the role and potential mechanism of mesothelin blockage by Amatuximab in human pancreatic cells both expressing high or low level of mesothelin in vitro experiment and peritonitis mouse model of pancreatic cancer.
RESULTS
Mesothelin blockage by Amatuximab lead to suppression of invasiveness and migration capacity in AsPC-1 and Capan-2 (high mesothelin expression) and reduce levels of pMET expression. The combination of Amatuximab and gemcitabine suppressed proliferation of AsPC-1 and Capan-2 more strongly than gemcitabine alone. These phenomena were not observed in Panc-1 and MIA Paca-2 (Mesothelin low expression). We previously demonstrated that Amatuximab reduced the peritoneal mass in mouse AsPC-1 peritonitis model and induced sherbet-like cancer cell aggregates, which were vanished by gemcitabine. In this study, we showed that the cancer stem cell related molecule such as ALDH1, CD44, c-MET, as well as proliferation related molecules, were suppressed in sherbet-like aggregates, but once sherbet-like aggregates attached to peritoneum, they expressed these molecules strongly without the morphological changes.
CONCLUSIONS
Our work suggested that Amatuximab inhibits the adhesion of cancer cells to peritoneum and suppresses the stemness and viability of those, that lead to enhance the sensitivity for gemcitabine.
Topics: Animals; Antibodies, Monoclonal; Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Pancreatic Ductal; Cell Adhesion; Cell Aggregation; Cell Division; Cell Movement; Cell Self Renewal; Deoxycytidine; Drug Resistance, Neoplasm; Drug Synergism; Female; GPI-Linked Proteins; Humans; Mesothelin; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasm Invasiveness; Neoplasm Proteins; Neoplastic Stem Cells; Organ Size; Pancreatic Neoplasms; Peritoneal Neoplasms; Peritoneum; Peritonitis; Gemcitabine
PubMed: 33637083
DOI: 10.1186/s12885-020-07722-3