Jacqueline Doody

Anti–Transforming Growth Factor β Receptor II Antibody Has Therapeutic Efficacy against Primary Tumor Growth and Metastasis through Multieffects on Cancer, Stroma, and Immune Cells

Purpose: Transforming growth factor β (TGFβ) is a pleiotropic cytokine that affects tumor growth, metastasis, stroma, and immune response. We investigated the therapeutic efficacy of anti–TGFβ receptor II (TGFβ RII) antibody in controlling metastasis and tumor growth as well as enhancing antitumor immunity in preclinical tumor models. Experimental Design: We generated neutralizing antibodies to TGFβ RII and assessed the antibody effects on cancer, stroma, and immune cells in vitro. The efficacy and mechanism of action of the antibody as monotherapy and in combination with chemotherapy in suppression of primary tumor growth and metastasis were evaluated in several tumor models. Results: Anti–TGFβ RII antibody blocked TGFβ RII binding to TGFβ 1, 2, and 3, and attenuated the TGFβ-mediated activation of downstream Smad2 kinase, invasion of cancer cells, motility of endothelial and fibroblast cells, and induction of immunosuppressive cells. Treatment with the antibody significantly suppressed primary tumor growth and metastasis and enhanced natural killer and CTL activity in tumor-bearing mice. Immunohistochemistry analysis showed cancer cell apoptosis and massive necrosis, and increased tumor-infiltrating T effector cells and decreased tumor-infiltrating Gr-1+ myeloid cells in the antibody-treated tumors. Fluorescence-activated cell sorting analysis indicated the significant reduction of peripheral Gr-1+/CD11b+ myeloid cells in treated animals. Concomitant treatment with the cytotoxic agent cyclophosphamide resulted in a significantly increased antitumor efficacy against primary tumor growth and metastasis. Conclusions: These preclinical data provide a foundation to support using anti–TGFβ RII antibody as a therapeutic agent for TGFβ RII–dependent cancer with metastatic capacity. Clin Cancer Res; 16(4); 1191–205

Inhibitory activity of cetuximab on epidermal growth factor receptor mutations in non-small cell lung cancers

Mutations in the kinase domain of the epidermal growth factor receptor (EGFR) were identified in ∼15% of all patients with non–small cell lung cancer (NSCLC). These mutations have been established as an indicator of superior response to gefitinib and erlotinib, small molecule inhibitors of the EGFR kinase domain. Whether these mutations would also render patients more susceptible to treatment with cetuximab (Erbitux), an EGFR-neutralizing antibody, is yet to be determined. In this study, we attempted to evaluate the effect of cetuximab on several NSCLC lines harboring some of the more common EGFR mutations (L858R and delL747-T753insS), as well as the recently identified kinase inhibitor–resistant mutation, T790M. We could show that the kinase activity of the abovementioned EGFR mutants was hindered by cetuximab, as detected by both cell-based phosphorylation and proliferation assays. Interestingly, cetuximab also induced enhanced degradation of the EGFR mutants as compared with the wild-type receptor. Most importantly, cetuximab successfully inhibited the growth of NSCLC lines in xenograft models. These results indicate the promising potential of cetuximab as a regimen for patients with NSCLC bearing these mutations. [Mol Cancer Ther 2007;6(10):2642–51]

Tumor necrosis factor-alpha and interleukin-1 antagonists alleviate inflammatory skin changes associated with epidermal growth factor receptor antibody therapy in mice.

Cancer patients receiving epidermal growth factor receptor (EGFR) antibody therapy often experience an acneiform rash of uncertain etiology in skin regions rich in pilosebaceous units. Currently, this condition is treated symptomatically with very limited, often anecdotal success. Here, we show that a monoclonal antibody targeting murine EGFR, ME1, caused a neutrophil-rich hair follicle inflammation in mice, similar to that reported in patients. This effect was preceded by the appearance of lipid-filled hair follicle distensions adjacent to enlarged sebaceous glands. The cytokine tumor necrosis factor-alpha (TNFalpha), localized immunohistochemically to this affected region of the pilosebaceous unit, was specifically up-regulated by ME1 in skin but not in other tissues examined. Moreover, skin inflammation was reduced by cotreatment with the TNFalpha signaling inhibitor, etanercept, indicating the involvement of TNFalpha in this inflammatory process. Interleukin-1, a cytokine that frequently acts in concert with TNFalpha, is also involved in this process given the efficacy of the interleukin-1 antagonist Kineret. Our results provide a mechanistic framework to develop evidence-based trials for EGFR antibody-induced skin rash in patients with cancer.

Generation of Fcabs targeting human and murine LAG-3 as building blocks for novel bispecific antibody therapeutics

The immunoglobulin superfamily protein lymphocyte-activation gene 3 (LAG-3) participates in immune suppression and has been identified as a suitable target for cancer therapies. In order to generate bispecific antibodies targeting LAG-3, Fcabs (Fc-region with antigen binding) targeting human and murine LAG-3 were generated from phage libraries. These Fcabs bind to LAG-3, inhibiting its interaction with MHC class II, and induce IL-2 production in a T cell assay. Bispecific antibodies, known as mAb2, were produced by replacing the Fc region of a monoclonal antibody with Fcab sequences in the CH3 domain. mAb2 containing anti-LAG-3 Fcabs have mAb-like biophysical characteristics and retain LAG-3 binding and functional activity. mAb2 can thus be generated using multiple Fabs to investigate bispecific parings and develop novel therapeutics.

Abstract 5651: A LAG-3/PD-L1 bispecific antibody inhibits tumor growth in two syngeneic colon carcinoma models

Combining immunotherapeutic antibodies in cancer treatment has shown benefits over single agents. An alternative to combining two antibodies is the development of bispecific antibodies that not only bring two biologies together but may result in novel mechanisms of action that are impossible to attain with combinations. Lymphocyte Activation Gene-3 (LAG-3) is a member of the Ig superfamily expressed on activated T cells, NK cells, pDCs, B cells, γδ T cells and participates in immune suppression. Programmed Cell Death receptor (PD-1) binds to its ligand PD-L1, expressed not only on activated immune cells to inhibit cellular immune responses but also on tumor cells. Expression of both these surface molecules therefore leads to T cell exhaustion allowing the tumor to escape immune surveillance. A mAb² TM (bispecific antibody) was engineered which binds murine LAG-3 and PD-L1 simultaneously and with nanomolar affinities. The anti-LAG-3/PD-L1 mAb² inhibits LAG-3 binding to MHCII and PD-L1 binding to PD-1 and CD80, resulting in T cell activation in vitro. This translates into in vivo efficacy, where the mAb² decreased tumor burden in the MC38 colon carcinoma tumor model. At the end of the study tumor-free animals were more numerous in the LAG-3/PD-L1 bispecific group than in the group given a combination of individual anti-LAG-3 and PD-L1 antibodies. The results were recapitulated in the CT26 murine colon cancer model, where the mAb² showed an increase of antitumor activity as compared to the antibodies given in combination. Thus, the preclinical data supports developing an anti-human LAG-3/PD-L1 mAb² for the treatment of cancer patients. Citation Format: Matthew Kraman, Katarzyna Kmiecik, Carlo Zimarino, Katy Everett, Mustapha Faroudi, Mateusz Wydro, Jacqueline Doody. A LAG-3/PD-L1 bispecific antibody inhibits tumor growth in two syngeneic colon carcinoma models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5651. doi:10.1158/1538-7445.AM2017-5651