Trifunctional antibodies induce efficient antitumour activity with immune cells from head and neck squamous cell carcinoma patients after radio-chemotherapy treatment

Plant-Produced Monoclonal Antibody as Immunotherapy for Cancer

Plant-based products have expanded to include cancer immunotherapy, which has made great strides over recent years. Plants are considered inexpensive and facile production platforms for recombinant monoclonal antibody (mAb) due to the latest advancements and diversification of transgenic techniques. Current human biologics, including those based on mAbs produced by fermentation technologies using primarily mammalian cell cultures, have been replaced by plant-produced mAbs, which are cost effective, more scalable, speedy, versatile, and safer. Moreover, the use of animals for antibody production is always a question of ethical unambiguity, and the suitability of animal models for predicting the immunogenicity of therapeutic mAbs in humans and transposition of the immunogenic potential of therapeutic antibodies in animals to the human situation has no scientific rationale. Quite a few plant-based mAbs are approved for the treatment of cancer, ranging from tumors to hematological malignancies. This review focuses on the cutting-edge approaches for using plant-derived mAbs to suppress or prevent cancers. It also discusses the avenues taken to prevent infection by oncogenic viruses, solid tumors, lymphomas, and other cancerous conditions using mAbs. The review emphasizes the use of a plant-derived monoclonal antibody as a premier platform to combat cancer.

Development and clinical application of anti-HER2 monoclonal and bispecific antibodies for cancer treatment

HER2-targeted immunotherapy consists of monoclonal antibodies (e.g. trastuzumab, pertuzumab), bispecific antibodies (e.g. MM-111, ertumaxomab) and activated T cells armed with anti-HER2 bispecific antibody (HER2Bi-aATC). Trastuzumab is a classic drug for the treatment of HER2 positive metastatic breast cancer. The combined application of pertuzumab, trastuzumab and paclitaxel has been suggested as a standard therapy for HER2 positive advanced breast cancer. The resistance to anti-HER2 antibody has resulted in disease progression. HER2-directed bispecific antibody may be a promising therapeutic approach for these patients. Ertumaxomab enhanced the interaction of immune effector cells and tumor cells. MM-111 simultaneously binds to HER2 and HER3 and blocks downstream signaling. Besides, HER2Bi-aATC is also an alternative therapeutic approach for HER2 positive cancers. In this review, we summarized the recent advancement of HER2-targeted monoclonal antibodies (trastuzumab, pertuzumab and T-DM1) and bispecific antibodies (MM-111, ertumaxomab and HER2Bi-aATC), especially focus on clinical trial results.

Monoclonal antibodies against human cancer stem cells

Cancer stem cells (CSCs) are a subpopulation of tumor cells that display self-renewal and tumor initiation capacity and the ability to give rise to the heterogenous lineages of cancer cells that comprise the tumor. CSCs exhibit intrinsic mechanisms of resistance to modern cancer therapeutics, allowing them to survive current cancer therapies and to initiate tumor recurrence and metastasis. Various cell surface and transmembrane proteins expressed by CSCs, including CD44, CD47, CD123, EpCAM (CD326), CD133, IGF receptor I, and proteins of the Notch and Wnt signaling pathways have been identified. Recently, monoclonal antibodies and antibody constructs raised against these CSC proteins have shown efficacy against CSCs in human cancer xenograft mice, and some of them have demonstrated antitumor activity in clinical studies. Since current cancer therapies fail to eliminate CSCs, leading to cancer recurrence and progression, selective targeting of CSCs with monoclonal antibodies and antibody constructs may represent a novel therapeutic strategy against cancer.

Antibodies directed against receptor tyrosine kinases: current and future strategies to fight cancer

Approximately 30 therapeutic monoclonal antibodies have already been approved for cancers and inflammatory diseases, and monoclonal antibodies continue to be one of the fastest growing classes of therapeutic molecules. Because aberrant signaling by receptor tyrosine kinases (RTKs) is a commonly observed factor in cancer, most of the subclasses of RTKs are being extensively studied as potential targets for treating malignancies. The first two RTKs that have been targeted by antibody therapy, with five currently marketed antibodies, are the growth factor receptors EGFR and HER2. However, due to systemic side effects, refractory patients and the development of drug resistance, these treatments are being challenged by emerging therapeutics. This review examines current monoclonal antibody therapies against RTKs. After an analysis of agents that have already been approved, we present an analysis of antibodies in clinical development that target RTKs. Finally, we highlight promising RTKs that are emerging as new oncological targets for antibody-based therapy.

Effects of radiation therapy on postoperative complications and adverse events in patients with head and neck reconstruction with flaps

BACKGROUND

Radiation therapy is an essential treatment for head and neck cancer. However, the condition of the operative field is entirely altered after radiation therapy. This study aimed to examine the effects of preoperative radiation therapy on complications in patients who underwent head and neck reconstruction with flaps.

METHODS

We retrospectively reviewed 252 instances of head and neck reconstruction with flaps in 240 patients between October 2000 and May 2011 at Okayama University Hospital. Of the participants, 51 had preoperative radiation exposure (21.3%) and 189 had no radiation exposure (78.7%). Postoperative complications were divided into three categories: minor complications that healed with conservative medical treatment within 4 weeks without a need for surgery; major complications requiring reoperation within 1 week after surgery (reoperation); and major complications needing additional operation later than 1 week after surgery (additional operation).

RESULTS

Preoperative radiation therapy was only associated with major complications requiring reoperation later than 1 week after surgery (P < 0.001), open cervical wounds (P = 0.0030), and skin grafting for cervical skin necrosis (P = 0.0031) when compared to no radiation exposure. The results of flap failure were not significantly different between both groups (P = 0.3820).

CONCLUSIONS

Minor complications and reoperation in the early postoperative period were not influenced by radiation exposure. The complications of radiation tend to be protracted and associated with additional operation later than 1 week after the initial surgery. It was thought that shortening of the duration of treatment was successful when we needed to perform early additional operations.

Targeted therapies for squamous cell carcinoma of the head and neck: current knowledge and future directions

Despite progress in the therapeutic management of patients with squamous cell carcinoma of the head and neck (SCCHN), the mortality rate of patients presenting with advanced disease remains high. One approach to improve treatment efficacy is to add novel molecular targeted agents to the classical treatment regimens. Monoclonal antibodies targeting the epidermal growth factor receptor (EGFR) have shown clinical benefits in palliative and curative settings. However, only a minority of patients presenting with recurrent or metastatic (R/M) SCCHN have meaningful tumor regression with these agents and virtually all who do develop acquired tumor resistance after a few months of treatment. For these reasons, other inhibitors of EGFR or molecules that interfere with known molecular pathways activated in SCCHN are of considerable interest, either as single agents or in combination with other treatment modalities. In this review, we discuss the different molecular therapeutic approaches explored in SCCHN. We also briefly outline new trial designs that could be used to accelerate the investigation of emerging therapeutic agents in this disease.

Anti-HER-2 anti-CD3 bi-specific antibodies inhibit growth of HCT-116 colorectal carcinoma cells in vitro and in vivo

OBJECTIVE

This study is conducted to evaluate the effects of anti-HER-2 anti-CD3 bi-specific antibodies(BsAb) on HER-2/neuover-expressing human colorectal carcinoma cells.

METHODS

Growth was assessed by MTT assays after exposure of HCT-116 cells to Herceptin, anti-CD3 and BsAb antibodies. Immunocytochemistry was applied to test the HER-2 level of HCT-116. In a nude mouse model, HER-2 CD3 BsAb was combined with effector cells (peripheral blood lymph cells from normal human being) for observations on in Vivo growth of tumors.

RESULTS

Compared with the control group, using effector cells combined with anti-CD3 McAb, Herceptin or HER2 CD3 BsAb, tumor cell growth in vitro and in vivo was significantly inhibited (P<0.05), most remarkably in the HER2 CD3 BsAb case. The growth of xenografts with HER2 CD3 BsAb combined with effector cells was also significantly inhibited when compared with the anti-CD3 McAb or Herceptin groups (P<0.05).

CONCLUSION

HER-2/neu might be a useful target for immunotherapy in colorectal carcinoma, anti-HER2 anti-CD3 BsAb exerting clear anti-tumor effects.

[Immunotherapy of head and neck cancer. Current developments]

In order to improve the prognosis for patients with head and neck squamous cell cancer (HNSCC) the introduction of new therapeutic strategies is necessary. The concept of immunotherapy has been applied and improved for several years and recent studies have used tumor-specific antigens which facilitates targeted oncologic therapy. However, immunotherapy is hampered by the fact that immunosuppressive mechanisms are pronounced and relevant effector cells are suppressed, especially in patients with HNSCC. Successful immunotherapy could induce an antitumor immune response by restitution of these cell populations. Current anti-tumor immunotherapy includes unspecific immune stimulation, genetic modification of tumor and immune cells, the use of monoclonal antibodies, e.g. cetuximab, adoptive cell transfer and tumor vaccination. In the future, these biologic therapies alone or in combination with conventional therapeutic regimens could present a valuable therapeutic option for HNSCC patients.

Trifunctional antibody ertumaxomab: Non-immunological effects on Her2 receptor activity and downstream signaling

BACKGROUND

The trifunctional antibody ertumaxomab bivalently targets the human epidermal growth factor receptor 2 (Her2) on epithelial (tumor) cells and the T cell specific CD3 antigen, and its Fc region is selectively recognized by Fcγ type I/III receptor-positive immune cells. As a trifunctional immunoglobulin, ertumaxomab therefore not only targets Her2 on cancer cells, but also triggers immunological effector mechanisms mediated by T and accessory cells (e.g., macrophages, dendritic cells, natural killer cells). Whether molecular effects, however, might contribute to the cellular antitumor efficiency of ertumaxomab are largely unknown.

METHODS

Potential molecular effects of ertumaxomab on Her2-overexpressing BT474 and SK-BR-3 breast cancer cells were evaluated. The dissociation constant Kd of ertumaxomab was calculated from titration curves that were recorded by flow cytometry. Treatment-induced changes in Her2 homodimerization were determined by flow cytometric fluorescence resonance energy transfer measurements on a cell-by-cell basis. Potential activation / deactivation of Her2, ERK1/2, AKT and STAT3 were analyzed by western blotting, Immunochemistry and immunofluorescent cell staining.

RESULTS

The Kd of ertumaxomab for Her2-binding was determined at 265 nM and the ertumaxomab binding epitope was found to not overlap with that of the therapeutic anti-Her2 monoclonal antibodies trastuzumab and pertuzumab. Ertumaxomab caused an increase in Her2 phosphorylation at higher antibody concentrations, but changed neither the rate of Her2-homodimerization /-phosphorylation nor the activation state of key downstream signaling proteins analyzed.

CONCLUSIONS

The unique mode of action of ertumaxomab, which relies more on activation of immune-mediated mechanisms against tumor cells compared with currently available therapeutic antibodies for breast cancer treatment, suggests that modular or sequential treatment with the trifunctional bivalent antibody might complement the therapeutic activity of other anti-Her2/anti-ErbB receptor reagents.