Studying the Presentation of Paget Disease of the Breast.

Paget disease of the breast is a rare breast cancer that accounts for 1-3% of all new presentations of breast cancer. It is characterized by an eczematous and ulcerative lesion of the nipple that may extend to the areola. Nearly 90% of cases are associated with underlying breast cancer. We report the presentation of Paget disease of the breast in a 41-year-old female, who presented due to a one-year history of an eczematous lesion of the left nipple area with no palpable mass, who was later found to have high-grade invasive ductal carcinoma treated with unilateral mastectomy and sentinel node biopsy.

Studying the Co-presentation of Focal Segmental Glomerulosclerosis and IgA Nephropathy in a Young Female With No Significant Risk Factors.

Focal segmental glomerulosclerosis (FSGS) and IgA nephropathy are among the most common glomerular disorders. FSGS is characterized by focal scarring affecting less than 50% of glomeruli while IgA nephropathy is characterized by the deposition of IgA in the mesangium of glomeruli. The presence of both of these diseases in a single patient is uncommon, but the presence of both in a young individual with no predisposing factors is exceedingly rare. As such, our case report outlines the unusual presentation of both of these disorders in a young Hispanic female with no known risk factors.

Conduit CAR: Redirecting CAR T-Cell Specificity with A Universal and Adaptable Bispecific Antibody Platform.

The success of chimeric antigen receptor (CAR) T-cell therapy against hematologic malignancies has altered the treatment paradigm for patients with these diseases. Nevertheless, the occurrence of relapse due to antigen escape or heterogeneous antigen expression on tumors remains a challenge for first-generation CAR T-cell therapies as only a single tumor antigen can be targeted. To address this limitation and to add a further level of tunability and control to CAR T-cell therapies, adapter or universal CAR T-cell approaches use a soluble mediator to bridge CAR T cells with tumor cells. Adapter CARs allow simultaneous or sequential targeting of multiple tumor antigens, control of immune synapse geometry, dose control, and the potential for improved safety. Herein, we described a novel CAR T-cell adapter platform that relies on a bispecific antibody (BsAb) targeting both a tumor antigen and the GGGGS (G4S) linker commonly used in single-chain Fv (ScFv) domains expressed on CAR T-cell surfaces. We demonstrated that the BsAb can bridge CAR T cells to tumor cells and potentiate CAR T-cell activation, proliferation, and tumor cell cytolysis. The cytolytic activity of CAR T-cells was redirected to different tumor antigens by changing the BsAb in a dose-dependent manner. This study highlights the potential of G4S-displaying CAR T cells to be redirected to engage alternative tumor-associated antigens (TAA). Significance: New approaches are needed to address relapsed/refractory disease and manage potential toxicities associated with CAR T-cell therapy. We describe an adapter CAR approach to redirect CAR T cells to engage novel TAA-expressing cells via a BsAb targeting a linker present on many clinical CAR T-cell therapeutics. We anticipate the use of such adapters could increase CAR T-cell efficacy and reduce potential CAR-associated toxicities.

Selective recruitment of γδ T cells by a bispecific antibody for the treatment of acute myeloid leukemia.

Despite significant progress over the last few decades in the treatment of acute myeloid leukemia (AML), there still remains a major unmet medical need for this disease. Immunotherapy approaches for redirecting pan CD3+ T cells to target leukemia blasts have shown limited efficacy in clinical trials and often accompanied with severe toxicity in AML patients. We designed an alternative engager molecule (Anti-TRGV9/anti-CD123), a bispecific antibody that can simultaneously bind to the Vγ9 chain of the Vγ9Vδ2+ γδ T cell receptor and to AML target antigen, CD123, to selectively recruit Vγ9+ γδ T cells rather than pan T cells to target AML blasts. Our results suggest that prototypic bispecific antibodies (a) selectively activate Vγ9+ γδ T cells as judged by CD69 and CD25 surface expression, and intracellular Granzyme B expression, (b) selectively recruit Vγ9+ γδ T cells into cell-cell conjugate formation of γδ T cells with tumor cells indicating selective and effective engagement of effector and target tumor cells, and (c) mediate γδ T cell cytotoxicity (in vitro and in vivo) against tumor antigen-expressing cells. Collectively, these findings suggest that selectively redirecting Vγ9+ γδ T cells to target AML blasts has a potential for immunotherapy for AML patients and favors further exploration of this concept.

Overcoming the challenges associated with CD3+ T-cell redirection in cancer.

The development of bispecific antibodies that redirect the cytotoxic activity of CD3+ T cells to tumours is a promising immunotherapeutic strategy for the treatment of haematological malignancies and solid cancers. Since the landmark FDA approval at the end of 2014 of the anti-CD3 × anti-CD19 bispecific antibody blinatumomab (Blincyto®) for the treatment of relapsed/refractory B-cell acute lymphoblastic leukaemia, ~100 clinical trials investigating the safety and efficacy of CD3+ bispecific T-cell redirectors for cancer have been initiated. However, despite early success, numerous challenges pertaining to CD3+ T-cell redirection in the context of cancer exist, including the recruitment of counterproductive CD3+ T-cell subsets, the release of systemic cytokines, the expansion of immune checkpoint molecules, the presence of an immunosuppressive tumour microenvironment, tumour antigen loss/escape, on-target off-tumour toxicity and suboptimal potency. The aim of the present review is to discuss novel approaches to overcome the key challenges associated with CD3+ bispecific T-cell redirection in order to achieve an optimal balance of anti-tumour activity and safety.

Bispecific Antibodies for Triple Negative Breast Cancer.

Triple negative breast cancer (TNBC), an aggressive breast cancer subtype lacking estrogen receptor (ER), progesterone receptor, and human epidermal growth factor receptor 2 (HER2) expression, is associated with heightened metastatic potential and poor prognosis. While systemic chemotherapy, radiation, and surgical excision remain the current treatment modalities for patients with TNBC, the immunogenic nature of this aggressive disease has presented opportunity for the development of TNBC-targeting immunotherapies. Bispecific antibody-based therapeutics for the treatment of TNBC have gained recent attention in the scientific community. Clinical precedent has been previously established for the FDA-approved bispecific T cell engager, blinatumomab, for acute lymphoblastic leukemia. The present review discusses novel bispecific antibodies for TNBC and emerging TNBC targets for future bispecific antibody development.

Harnessing SLE Autoantibodies for Intracellular Delivery of Biologic Therapeutics.

Intracellular delivery of therapeutic antibodies is highly desirable but remains a challenge for biomedical research and the pharmaceutical industry. Approximately two-thirds of disease-associated targets are found inside the cell. Difficulty blocking these targets with available drugs creates a need for technology to deliver highly specific therapeutic antibodies intracellularly. Historically, antibodies have not been believed to traverse the cell membrane and neutralize intracellular targets. Emerging evidence has revealed that anti-DNA autoantibodies found in systemic lupus erythematosus (SLE) patients can penetrate inside the cell. Harnessing this technology has the potential to accelerate the development of drugs against intracellular targets. Here, we dissect the mechanisms of the intracellular localization of SLE antibodies and discuss how to apply these insights to engineer successful cell-penetrating antibody drugs.

Innate and Innate-Like Cells: The Future of Chimeric Antigen Receptor (CAR) Cell Therapy.

Conventional αß CAR-T cell-based approaches have revolutionized the field of cancer immunotherapy, but hurdles remain, especially for solid tumors. Novel strategies in conjunction with alternative cell types are therefore required for effective CAR-based therapies. In this respect, innate and innate-like cells with unique immune properties, such as natural killer (NK) cells, NKT cells, γδ T cells, and macrophages, are promising alternatives to αß CAR-T adoptive therapy. We review the applicability of these cells in the context of CAR therapy, focusing on therapies under development, the advantages of these approaches relative to conventional CAR-T cells, and their potential in allogeneic therapies. We also discuss the inherent limitations of these cell types and approaches, and outline numerous strategies to overcome the associated obstacles.

Regulatory T cell targeting in cancer: Emerging strategies in immunotherapy.

The adaptive immune system is modulated by an important subset of CD4+ T lymphocytes called Treg cells that function in maintaining immune homeostasis by preventing excessive immune activation. Both deficiency and overactivation of Treg cell function can result in disease pathology. While loss of Treg function can lead to autoimmunity, an overabundance of Treg activity can promote tumorigenesis. Blocking and/or depleting Tregs has emerged as a viable strategy to enhance antitumor immunity. A major limitation underlying the limited efficacy observed with Treg therapies in the clinic is lack of selective targeting, often attributed to concurrent depletion of antitumor effector T-cell populations. Novel approaches to improve the specificity of Treg targeting in the context of cancer include the use of T-cell receptor mimic antibodies, bispecific antibodies, and near-infrared photoimmunotherapy. Next-generation technology platforms and transcriptomic/computational-based screening methods have been recently developed to identify preferential Treg targets. Herein, we highlight key advancements and challenges pertaining to the development of novel Treg targeting cancer therapeutics and discuss ongoing clinical trials evaluating next-generation Treg therapies for solid tumors.

Emerging CAR-T Cell Therapy for the Treatment of Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC), a highly aggressive breast cancer subtype that lacks estrogen receptor, progesterone receptor, and HER2 expression, does not respond to traditional endocrine and anti-HER2-targeted therapies. Current treatment options for patients with TNBC include a combination of surgery, radiotherapy, and/or systemic chemotherapy. FDA-approved therapies that target DNA damage repair mechanisms in TNBC, such as PARP inhibitors, only provide marginal clinical benefit. The immunogenic nature of TNBC has prompted researchers to harness the body's natural immune system to treat this aggressive breast cancer. Clinical precedent has been recently established with the FDA approval of two TNBC immunotherapies, including an antibody-drug conjugate and an anti-programmed death-ligand 1 monoclonal antibody. Chimeric antigen receptor (CAR)-T cell therapy, a type of adoptive cell therapy that combines the antigen specificity of an antibody with the effector functions of a T cell, has emerged as a promising immunotherapeutic strategy to improve the survival rates of patients with TNBC. Unlike the remarkable clinical success of CAR-T cell therapies in hematologic cancers with Kymriah and Yescarta, the development of CAR-T cell therapies for solid tumors has been much slower and is associated with unique challenges, including a hostile tumor microenvironment. The aim of the present review is to discuss novel approaches and inherent challenges pertaining to CAR-T cell therapy for the treatment of TNBC.

Combination of CD40 Agonism and CSF-1R Blockade Reconditions Tumor-Associated Macrophages and Drives Potent Antitumor Immunity.

Efficacious antitumor immune responses must overcome multiple suppressive mechanisms in the tumor microenvironment to control cancer progression. In this study, we demonstrate that dual targeting of suppressive myeloid populations by inhibiting CSF-1/CSF-1R signaling and activation of antigen-presenting cells with agonist anti-CD40 treatment confers superior antitumor efficacy and increased survival compared with monotherapy treatment in preclinical tumor models. Concurrent CSF-1R blockade and CD40 agonism lead to profound changes in the composition of immune infiltrates, causing an overall decrease in immunosuppressive cells and a shift toward a more inflammatory milieu. Anti-CD40/anti-CSF-1R-treated tumors contain decreased tumor-associated macrophages and Foxp3+ regulatory T cells. This combination approach increases maturation and differentiation of proinflammatory macrophages and dendritic cells and also drives potent priming of effector T cells in draining lymph nodes. As a result, tumor-infiltrating effector T cells exhibit improved responses to tumor antigen rechallenge. These studies show that combining therapeutic approaches may simultaneously remove inhibitory immune populations and sustain endogenous antitumor immune responses to successfully impair cancer progression. Cancer Immunol Res; 5(12); 1109-21. ©2017 AACR.

Distinct apoptotic signaling characteristics of the anti-CD40 monoclonal antibody dacetuzumab and rituximab produce enhanced antitumor activity in non-Hodgkin lymphoma.

PURPOSE: Individually targeting B-cell antigens with monoclonal antibody therapeutics has improved the treatment of non-Hodgkin lymphoma (NHL). We examined if the antitumor activity of rituximab, CD20-specific antibody, could be improved by simultaneously targeting CD40 with the humanized monoclonal antibody dacetuzumab (SGN-40). EXPERIMENTAL DESIGN: Dacetuzumab was dosed with rituximab to determine the in vivo activity of this combination in a subcutaneous Ramos xenograft model of non-Hodgkin lymphoma (NHL). The effect of dacetuzumab on rituximab antibody-dependent cell mediated-cytotoxicity (ADCC), antiproliferative, and apoptotic activities were evaluated in vitro using NHL cell lines. Western blotting and flow cytometry were used to contrast the signaling pathways activated by dacetuzumab and rituximab in NHL cells. RESULTS: The dacetuzumab-rituximab combination had significantly improved antitumor activity over the equivalent dose of rituximab in the Ramos xenograft model (P = 0.0021). Dacetuzumab did not augment rituximab-mediated ADCC activity; however, these antibodies were additive to synergistic in cell-proliferation assays and produced increased apoptosis in combination. Rituximab signaling downregulated BCL-6 oncoprotein in a cell line-specific manner, whereas dacetuzumab strongly downregulated BCL-6 in each cell line. Dacetuzumab induced expression of the proapoptotic proteins TAp63 and Fas, whereas rituximab did not affect basal expression of either protein. Finally, rituximab partially blocked dacetuzumab-mediated upregulation of the prosurvival protein BCL-x(L). CONCLUSIONS: Targeting CD40 with dacetuzumab enhanced the antitumor activity of rituximab in cell line and xenograft NHL models. The distinct but complementary apoptotic signal transduction profiles of dacetuzumab and rituximab are an important mechanism behind the improved activity of this combination.

5-azacytidine enhances the anti-leukemic activity of lintuzumab (SGN-33) in preclinical models of acute myeloid leukemia.

Despite therapeutic advances, the poor prognoses for acute myeloid leukemia (AML) and intermediate and high-risk myelodysplastic syndromes (MDS) point to the need for better treatment options. AML and MDS cells express the myeloid marker CD33, making it amenable to CD33-targeted therapy. Lintuzumab (SGN-33), a humanized monoclonal anti-CD33 antibody undergoing clinical evaluation, induced meaningful responses in a Phase 1 clinical trial and demonstrated anti-leukemic activity in preclinical models. Recently, it was reported that 5-azacytidine (Vidaza™) prolonged the overall survival of a group of high risk MDS and AML patients. To determine whether the combination of lintuzumab and 5-azacytidine would be beneficial, a mouse xenograft model of disseminated AML was used to evaluate the combination.  There was a significant reduction in tumor burden and an increase in overall survival in mice treated with lintuzumab and 5-azacytidine. The effects were greater than that obtained with either agent alone. As the in vivo anti-leukemic activity of lintuzumab was dependent upon the presence of mouse effector cells including macrophages and neutrophils, in vitro effector function assays were used to assess the impact of 5-azacytidine on lintuzumab activity. The results show that 5-azacytidine significantly enhanced the ability of lintuzumab to promote tumor cell killing through antibody-dependent cellular cytotoxicity (ADCC) and phagocytic (ADCP) activities. These results suggest that lintuzumab and 5-azacytidine act in concert to promote tumor cell killing. Additionally, these findings provide the rationale to evaluate this combination in the clinic.

Targeting inflammatory cells to improve anti-VEGF therapies in oncology.

Vascular endothelial growth factor A (VEGF-A) is a well-characterized regulator of physiological and pathological angiogenesis. Multiple therapeutic compounds interfering with VEGF-A-regulated signal transduction pathways are currently being developed for the treatment of neoplasias and other malignancies associated with pathological angiogenesis. A major challenge in developing anti-VEGF therapies are tumor intrinsic refractoriness and the emergence of treatment-induced resistance. A variety of molecular and cellular mechanisms contribute to tumor angiogenesis, including the recruitment of bone marrow (BM)-derived endothelial cell progenitors (EPCs) and inflammatory cells to the tumor mass. Among the latter, two types of tumor infiltrating, inflammatory cells were recently identified to mediate refractoriness to anti-VEGF treatment: CD11b + Gr1+ myeloid derived suppressor cells (MDSC) and tumor-associated macrophages (TAMs). In this chapter, we review some of the inflammatory components regulating tumor angiogenesis and their roles in mediating refractoriness toward anti-VEGF treatment. In addition, we discuss potential therapeutic strategies targeting angiogenic pathways regulated by inflammatory cells. A better understanding of the biological and molecular events involved in mediating refractoriness to anti-VEGF treatment may help to further improve therapeutic strategies targeting tumor angiogenesis.

Overview of TNF superfamily: a chest full of potential therapeutic targets.

Since the discovery of tumor necrosis factor TNFalpha about 25 years ago, TNF superfamily has grown to a large family of related proteins consisting of over 20 members that signal through over 30 receptors. Members of this superfamily have wide tissue distribution and play important roles ranging from regulation of the normal biological processes such as immune responses, hematopoiesis and morphogenesis to their role in tumorigenesis, transplant rejection, septic shock, viral replication, bone resorption and autoimmunity. Thus, many approaches to harness the potency of TNF superfamily members to treat human diseases have been developed. Indeed, TNF and TNF agonistic molecules have been approved for human use in the United States and other countries. Many other TNF family members show promise for several therapeutic applications, including cancer, infectious disease, transplantation and autoimmunity. This chapter will give overview of TNF superfamily for exploitation for therapeutic use in humans.

Therapeutic interventions targeting CD40L (CD154) and CD40: the opportunities and challenges.

CD40 was originally identified as a receptor on B-cells that delivers contact-dependent T helper signals to B-cells through interaction with CD40 ligand (CD40L, CD154). The pivotal role played by CD40-CD40L interaction is illustrated by the defects in B-lineage cell development and the altered structures of secondary lymphoid tissues in patients and engineered mice deficient in CD40 or CD40L. CD40 signaling also provides critical functions in stimulating antigen presentation, priming of helper and cytotoxic T-cells and a variety of inflammatory reactions. As such, dysregulations in the CD40-CD40L costimulation pathway are prominently featured in human diseases ranging from inflammatory conditions to systemic autoimmunity and tissue-specific autoimmune diseases. Moreover, studies in CD40-expressing cancers have provided convincing evidence that the CD40-CD40L pathway regulates survival of neoplastic cells as well as presentation of tumor-associated antigens to the immune system. Extensive research has been devoted to explore CD40 and CD40L as drug targets. A number of anti-CD40L and anti-CD40 antibodies with diverse biological effects are in clinical development for treatment of cancer and autoimmune diseases. This chapter reviews the role of CD40-CD40L costimulation in disease pathogenesis, the characteristics of therapeutic agents targeting this pathway and status of their clinical development.

Targeting of BAFF and APRIL for autoimmunity and oncology.

BLyS and APRIL are tumor necrosis factor superfamily members shown to be important for B-cell development, maturation and survival. Recent data also indicate that these cytokines regulate the survival and maintenance of malignant B-cells in cancer patients. The key role of BlyS/APRIL in the immune system and their potential role in cancers have attracted the attention of basic scientistis and biotechnology companies alike. As a result, the pathways regulated by BLYS and APRIL have been quickly elevated as attractive targets for antibody-based and non-antibody based therapeutics. Exploitation of these pathways has not only given us enormous insights into the basic biology of the APRIL/BLyS system but it has also identified potential clinical candidates for cancer and autoimmunity. As such, multiple biotechnology companies are currently testing various therapeutic candidates in the clinic. This chapter will review BLyS and APRIL functions and discuss alternative therapeutic approaches to target BLyS and APRIL pathways for human malignancies and autoimmunity.

Targeting CD70 for human therapeutic use.

Expression of CD70, a member of the tumor necrosis factor superfamily, is restricted to activated T-and B-lymphocytes and mature dendritic cells. Binding of CD70 to its receptor, CD27, is important in priming, effector functions, differentiation and memory formation of T-cells as well as plasma and memory B-cell generation. Antibody blockade of CD70-CD27 interaction inhibits the onset of experimental autoimmune encephalomyelits and cardiac allograft rejection in mice. CD70 has been also detected on hematological tumors and on carcinomas. The highly restricted expression pattern of CD70 in normal tissues and its widespread expression in various malignancies as well as its potential role in autoimmune and inflammatory conditions makes it an attractive target for antibody-based therapeutics. This chapter provides an overview of the physiological role of CD70-CD27 interactions and discusses various approaches to target this pathway for therapeutic use in cancers and autoimmunity.

Targeting CD30/CD30L in oncology and autoimmune and inflammatory diseases.

The transmembrane receptor CD30 (TNFRSF8) and its ligand CD30L (CD153, TNFSF8) are members of the tumor necrosis factor (TNF) superfamily and display restricted expression in subpopulations of activated T-and B-cells in nonpathologic conditions. CD30 expression is upregulated in various hematological malignancies, including Reed-Sternberg cells in Hodgkin's disease (HD), anaplastic large cell lymphoma (ALCL) and subsets of Non-Hodgkin's lymphomas (NHLs). Increased CD30L expression was found on mast cells within HD tumors and preclinical and clinical studies with compounds targeting the CD30/ CD30L system in HD and ALCL demonstrated therapeutic benefit. Upregulation of CD30 and CD30L is also linked to leukocytes in patients with chronic inflammatory diseases, including lupus erythematosus, asthma, rheumatoid arthritis and atopic dermatitis (AD). Preclinical studies conducted with transgenic mice or biologic compounds suggested important regulatory functions of the CD30-CD30L system in various aspects of the immune system. Such key regulatory roles and their low expression in normal conditions combined with increased expression in malignant tissues provided a strong rationale to investigate CD30 and CD30L as therapeutic targets in hematologic malignancies, autoimmune and inflammatory diseases. In this report, we review the pharmacodynamic effects of specific therapeutic compounds targeting the CD30/CD30L system in preclinical- and clinical studies.

Blocking of CD27-CD70 pathway by anti-CD70 antibody ameliorates joint disease in murine collagen-induced arthritis.

Rheumatoid arthritis (RA) is characterized by inflammation and cellular proliferation in the synovial lining of joints that result in cartilage and bone destruction. Although the etiology of RA is unclear, activated lymphocytes and proinflammatory molecules, in particular TNF superfamily members, have been implicated in the disease pathology. A TNF superfamily member, CD70, is found on activated lymphocytes and shown to be important in memory and effector responses of lymphocytes. CD70 is expressed at high levels on chronically activated T cells in patients with autoimmune disorders, including RA. The involvement of CD70 in the progression of RA, however, remains unknown. In this study, we report effects of targeting CD70 on disease pathogenesis by using an anti-mouse CD70 Ab in a murine model of collagen-induced arthritis (CIA). In addition to blocking CD70 binding to its receptor CD27, the anti-CD70 Ab used also engages Fc-dependent effector functions including Ab-dependent cellular cytotoxicity, phagocytosis, and complement fixation. Treatment of mice with anti-CD70 Ab both before the onset or after the established disease in CIA model resulted in marked improvements in disease severity and significant reduction in the production of autoantibodies. Histopathological analyses of the joints of mice revealed a substantial reduction of inflammation, and bone and cartilage destruction in response to the anti-CD70 Ab treatment. These results uncover a novel role for CD27-CD70 interactions in the regulation of in vivo inflammatory response leading to arthritis, and provide a molecular basis to support the rationale for anti-CD70 therapy for autoimmune and inflammatory diseases.