Development and characterization of agonistic antibodies targeting the Ig-like 1 domain of MuSK

Muscle-specific kinase (MuSK) is crucial for acetylcholine receptor (AChR) clustering and thereby neuromuscular junction (NMJ) function. NMJ dysfunction is a hallmark of several neuromuscular diseases, including MuSK myasthenia gravis. Aiming to restore NMJ function, we generated several agonist monoclonal antibodies targeting the MuSK Ig-like 1 domain. These activated MuSK and induced AChR clustering in cultured myotubes. The most potent agonists partially rescued myasthenic effects of MuSK myasthenia gravis patient IgG autoantibodies in vitro. In an IgG4 passive transfer MuSK myasthenia model in NOD/SCID mice, MuSK agonists caused accelerated weight loss and no rescue of myasthenic features. The MuSK Ig-like 1 domain agonists unexpectedly caused sudden death in a large proportion of male C57BL/6 mice (but not female or NOD/SCID mice), likely caused by a urologic syndrome. In conclusion, these agonists rescued pathogenic effects in myasthenia models in vitro, but not in vivo. The sudden death in male mice of one of the tested mouse strains revealed an unexpected and unexplained role for MuSK outside skeletal muscle, thereby hampering further (pre-) clinical development of these clones. Future research should investigate whether other Ig-like 1 domain MuSK antibodies, binding different epitopes, do hold a safe therapeutic promise

CD70 and PD-L1 in anaplastic thyroid cancer : promising targets for immunotherapy

Aims: During recent years, immune checkpoint inhibition has proved to be effective in several solid malignancies. The aim of this study was to identify novel targets for immunotherapy in anaplastic thyroid cancer by analysis of the expression of tumour antigens for which therapeutic agents are available. Method and results: By immunohistochemistry we observed tumoral expression of CD70 in 49% of cases. Expression of its receptor, CD27, was present mainly in lymphocytes surrounding and infiltrating the tumour and observed only rarely in tumour cells. CD70 expression was associated with the presence of a precursor papillary thyroid carcinoma and the presence of BRAF V600E mutations in the anaplastic thyroid cancer lesion. Furthermore, the expression of CD70 seems stable during progression of the disease. Tumoral expression of programmed cell death ligand 1 (PD-L1) was found in 28.6% of the anaplastic thyroid cancer cases. Programmed cell death 1 (PD-1), the receptor of PD-L1, was not expressed on the tumour cells. No association between CD70 expression and PD-L1 expression could be demonstrated. Conclusion: These data suggest that targeted immunotherapy for CD70/CD27 and PD-L1/PD-1 might be promising in anaplastic thyroid cancer. However, as a low amount of tumour-infiltrating lymphocytes was observed in most lesions, combined therapy with agents enhancing the invasion of lymphocytes in the tumour region needs to be considered

CD70 and PD-L1 in anaplastic thyroid cancer : promising targets for immunotherapy

Aims: During recent years, immune checkpoint inhibition has proved to be effective in several solid malignancies. The aim of this study was to identify novel targets for immunotherapy in anaplastic thyroid cancer by analysis of the expression of tumour antigens for which therapeutic agents are available. Method and results: By immunohistochemistry we observed tumoral expression of CD70 in 49% of cases. Expression of its receptor, CD27, was present mainly in lymphocytes surrounding and infiltrating the tumour and observed only rarely in tumour cells. CD70 expression was associated with the presence of a precursor papillary thyroid carcinoma and the presence of BRAF V600E mutations in the anaplastic thyroid cancer lesion. Furthermore, the expression of CD70 seems stable during progression of the disease. Tumoral expression of programmed cell death ligand 1 (PD-L1) was found in 28.6% of the anaplastic thyroid cancer cases. Programmed cell death 1 (PD-1), the receptor of PD-L1, was not expressed on the tumour cells. No association between CD70 expression and PD-L1 expression could be demonstrated. Conclusion: These data suggest that targeted immunotherapy for CD70/CD27 and PD-L1/PD-1 might be promising in anaplastic thyroid cancer. However, as a low amount of tumour-infiltrating lymphocytes was observed in most lesions, combined therapy with agents enhancing the invasion of lymphocytes in the tumour region needs to be considered

Unlocking the potential of CD70 as a novel immunotherapeutic target for non-small cell lung cancer

Although normally restricted to activated T and B cells and mature dendritic cells, constitutive expression of CD70, a member of the tumor necrosis family, has been described in both hematological and solid tumors, where it increases tumor cell and regulatory T cell survival by signaling through its receptor, CD27. We have assessed the co-expression of CD70 and CD27 in non-small cell lung cancer (NSCLC) by immunohistochemistry to explore a correlation between expression of the protein and tumor histologic subtype, genetic aberrations and prognosis. Furthermore, we tested the ability of ARGX-110, a CD70-blocking antibody, to induce NK cell-mediated cytotoxicity. Our results revealed CD70 expression on the surface of both primary and metastatic NSCLC tumor cells and in the tumor microenvironment. Moreover, CD27-expressing tumor infiltrating lymphocytes were found adjacent to the tumor cells, suggesting active CD70-mediated signaling. Finally, we have shown that ARGX-110, has potent cytotoxic effects on CD70(+) NSCLC cell lines

Bivalent Llama Single-Domain Antibody Fragments against Tumor Necrosis Factor Have Picomolar Potencies due to Intramolecular Interactions

International audienceThe activity of tumor necrosis factor (TNF), a cytokine involved in inflammatory pathologies, can be inhibited by antibodies or trap molecules. Herein, llama-derived variable heavy-chain domains of heavy-chain antibody (VHH, also called Nanobodies™) were generated for the engineering of bivalent constructs, which antagonize the binding of TNF to its receptors with picomolar potencies. Three monomeric VHHs (VHH#1, VHH#2, and VHH#3) were characterized in detail and found to bind TNF with sub-nanomolar affinities. The crystal structures of the TNF-VHH complexes demonstrate that VHH#1 and VHH#2 share the same epitope, at the center of the interaction area of TNF with its TNFRs, while VHH#3 binds to a different, but partially overlapping epitope. These structures rationalize our results obtained with bivalent constructs in which two VHHs were coupled via linkers of different lengths. Contrary to conventional antibodies, these bivalent Nanobody™ constructs can bind to a single trimeric TNF, thus binding with avidity and blocking two of the three receptor binding sites in the cytokine. The different mode of binding to antigen and the engineering into bivalent constructs supports the design of highly potent VHH-based therapeutic entities

Preclinical data on the combination of cisplatin and anti-CD70 therapy in non-small cell lung cancer as an excellent match in the era of combination therapy

In contrast to the negligible expression of the immunomodulating protein CD70 in normal tissue, we have demonstrated constitutive overexpression of CD70 on tumor cells in a subset of primary non-small cell lung cancer (NSCLC) biopsies. This can be exploited by CD70-targeting antibody-dependent cellular cytotoxicity (ADCC)-inducing antibodies. Early clinical trials of these antibodies have already shown promising results in CD70-positive malignancies. In this study, we explored the potential of cisplatin to induce CD70 expression in NSCLC. Using real-time measurement tools, we also assessed the efficacy of a combination regimen with cisplatin and anti-CD70 therapy under normoxia and hypoxia. We identified an induction of CD70 expression on lung cancer cells upon low doses of cisplatin, independent of oxygen levels. More importantly, the use of cisplatin resulted in an enhanced ADCC-effect of anti-CD70 therapy. As such, this combination regimen led to a significant decrease in lung cancer cell survival cell survival, broadening the applicability the applicability of CD70-targeting therapy. This is the first study that proves the potential of a combination therapy with cisplatin and CD70-targeting drugs in NSCLC. Based on our data, we postulate that this combination strategy is an interesting approach to increase tumor-specific cytotoxicity and reduce drug-related side effects