Immunology and Biotherapies

Abstract

Scientific insights into the human immune system have recently led to unprecedented breakthroughs in immunotherapy. In the twenty-first century, drugs and cell-based therapies developed to bolster humoral and T cell immunity represent an established and growing component of cancer therapeutics. Although natural killer (NK) cells have long been known to have advantages over T cells in terms of their capacity to induce antigen-independent host immune responses against malignancies, their therapeutic potential in the clinic has been largely unexplored. A growing number of scientific discoveries into pathways that both activate and suppress NK cell function, as well as methods to sensitize tumours to NK cell cytotoxicity, have led to the development of numerous pharmacological and genetic methods to enhance NK cell antitumour immunity. These findings, as well as advances in our ability to expand NK cells ex vivoand manipulate their capacity to home to the tumour, have now provided investigators with a variety of new methods and strategies to harness the full potential of NK cell-based cancer immunotherapy in the clinic.

Via Krishan Maggon

MT @NatRevClinOncol A shed NKG2D ligand that promotes NK cell activation & #tumor rejection http://t.co/fjxcQRyDGS #immunotherapy #cancer

 

Abstract

 

Immune cells, including natural killer (NK) cells, recognize transformed cells and eliminate them in a process termed immunosurveillance. It is thought that tumor cells evade immunosurveillance by shedding membrane ligands that bind to the NKG2D activating receptor on NK cells and/or T cells, and desensitize these cells. In contrast, we show that in mice, shedding of MULT1, a high affinity NKG2D ligand, causes NK cell activation and tumor rejection. Recombinant soluble MULT1 stimulated tumor rejection in mice. Soluble MULT1 functions, at least in part, by competitively reversing a global desensitization of NK cells imposed by engagement of membrane NKG2D ligands on tumor-associated cells, such as myeloid cells. The results overturn conventional wisdom that soluble ligands are inhibitory, and suggest a new approach for cancer immunotherapy.

Via Krishan Maggon

Vaccine-based cancer immunotherapy has generated highly variable clinical results due to differing methods of vaccine preparation and variation in patient populations, among other lesser factors. M...

Via Krishan Maggon

Affimed develops TandAbs and Trispecific Abs for substantially increasing the efficacy and extend the therapeutic window by three proprietary platforms

Via Krishan Maggon

Highlights

 

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Ex vivo expansion could derive NKTm cells with high proliferation efficiency.

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NKTm immunotherapy prolongs OS and increases 2-year survival rate of NSCLC patients.

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NKTm immunotherapy is an independent risk factor for OS of NSCLC patients.

Via Krishan Maggon

(2015). Macrophages are critical effectors of antibody therapies for cancer. mAbs: Vol. 7, No. 2, pp. 303-310.

Via Krishan Maggon

Abstract

Interleukin (IL)-15 is one of the most promising molecules to be used in antitumor immune therapy, as it is able to stimulate the main killer cells of both the innate and adaptive immune system. Although this cytokine can be used as a stand-alone immunotherapeutic agent, IL-15 will probably be most efficient in combination with other strategies to overcome high tumor burden, immune suppression of the tumor microenvironment and/or the short half-life of IL-15. In this review, we will discuss the combination strategies with IL-15 that have been tested to date in different animal tumor models, which include chemotherapy, other immunostimulatory cytokines, targeted therapy, adoptive cell transfer and gene therapy. In addition, we give an overview of IL-15 combination therapies that are currently tested in clinical studies to treat patients with hematological or advanced solid tumors.

Via Krishan Maggon

Abstract

Dendritic cell (DC) vaccination and cytokine-induced killer (CIK) cell therapy (DC/CIK) have shown limited success in the treatment of advanced non-small cell lung cancer (NSCLC). To investigate the reason for this limited success, the effects of DC/CIK cell therapy on the immune responses of tumor-bearing patients and patients with resected NSCLC were evaluated. In the total 50 patients studied, the serum concentrations of the Th2 cytokines (IL-4 and IL-10) in tumor-bearing patients were significantly higher than those with resected NSCLC before immunotherapy. The post-therapy Th1 cytokine (IFN-γ) level in patients with resected NSCLC significantly increased from the pre-therapy level. In contrast, significantly enhanced post-therapy Th2 cytokine (IL-4 and IL-10) levels were found in tumor-bearing patients. The intracellular staining assay revealed that DC/CIK cell therapy increased the IFN-γ-producing T lymphocyte (CD8+IFN-γ+) frequency in patients with resected NSCLC, but these lymphocytes were not found in tumor-bearing patients. Furthermore, overproduction of vascular endothelial growth factor (VEGF) in tumor-bearing patients showed a statistically positive correlation with IL-4, suggesting that VEGF might be responsible for the predominance of serum Th2 cytokines. In a word, tumor-bearing patients developed a Th2-dominant status that could not be reversed toward Th1 following immunotherapy. A combined regiment of DC vaccination and CIK cell therapy with other treatments to overcome systemic Th2-dominant immune response might improve the current clinical benefit.

Via Krishan Maggon

Immunotherapies for cancer are demonstrating increasing success. These agents can amplify existent antitumour immunity or induce durable antitumour immune responses in a wide array of cancers. The spectrum of immunotherapeutics is broad, spanning monoclonal antibodies and their derivatives, tumour vaccines, and adoptive therapies using T cells and natural killer cells.

Only a small number of immunotherapies have been tested in paediatric cancers, but impressive antitumour effects have already been observed. Mononclonal antibodies targeting GD2 that induce antibody-dependent cell-mediated cytotoxicity improve survival in high-risk neuroblastoma. Bi-specific monoclonal antibodies that simultaneously target CD19 and activate T cells can induce remission in acute B-cell lymphoblastic leukaemia (B-ALL) and adoptive immunotherapy using T cells genetically engineered to express chimeric antigen receptors targeting CD19 induce impressive responses in B-ALL. Efforts are underway to generate and test new immunotherapies in a wider array of paediatric cancers. Major challenges include a need to identify immunotherapy targets on the most lethal childhood cancers, to expand availability of technology-intense platforms, such as adoptive cell therapy, to optimize management of novel toxicities associated with this new class of cancer therapies and to determine how best to incorporate these therapies into standard treatment paradigms.

Via Krishan Maggon

Ektomun® is a member of the highly innovative, validated family of Triomab® antibodies. It combines the halves of two distinct full-size antibodies, a GD2-specific mouse antibody and a T -cell specific rat antibody, in one molecule.

 

GD2 is a clinically validated tumor target opening many potential applications for ektomun®. It is broadly present in tumors of neuroectodermal origin, including small cell lung cancer (SCLC), melanoma, neuroblastoma and glioblastoma. In healthy tissues, however, GD2 expression is strictly limited to very few, distinct cell types.

 

Due to its trifunctional design, ektomun® can simultaneously bind to GD2, expressed by  tumor cells, to a T-cell and, via its Fc-region, to an accessory cell of the innate immune system, as e.g. macrophages, dendritic or NK cells.

 

The resulting tri-cell-complex triggers multiple immune mechanisms at the same time.  Not only are tumor cells specifically and potently destroyed, but a long-lasting anti-tumor immunity is also induced – an effect that can otherwise only be achieved through vaccination.

Via Krishan Maggon