Cellular immunotherapy of cancer

Advancing Immunotherapy in Pancreatic Cancer

Pancreatic cancer remains one of the deadliest malignancies, with a consistently low five-year survival rate for the past several decades. This is in stark contrast to other cancers, which have seen significant improvement in survival and prognosis due to recent developments in therapeutic modalities. These modest improvements in pancreatic cancer outcomes have primarily resulted from minor advances in cytotoxic chemotherapeutics, with limited progress in other treatment approaches. A major focus of current therapeutic research is the further development of immunomodulatory therapies characterized by antibody-based approaches, cellular therapies, and vaccines. Although initial results utilizing immunotherapy in pancreatic cancer have been mixed, recent clinical trials have demonstrated significant improvements in patient outcomes. In this review, we detail these three approaches to immunomodulation, highlighting their common targets and distinct shortcomings, and we provide a narrative summary of completed and ongoing clinical trials that utilize these approaches to immunomodulation. Within this context, we aim to inform future research efforts by identifying promising areas that warrant further exploration.

Human regulatory B cells in health and disease: therapeutic potential

Regulatory B cells (Bregs) modulate immune responses predominantly, although not exclusively, via the release of IL-10. The importance of human Bregs in the maintenance of immune homeostasis comes from a variety of immune-related pathologies, such as autoimmune diseases, cancers, and chronic infections that are often associated with abnormalities in Breg numbers or function. A continuous effort toward understanding Breg biology in healthy individuals will provide new opportunities to develop Breg immunotherapy that could prove beneficial in treating various immune-mediated pathologies. In this Review, we discuss findings regarding human Bregs, including their mechanisms of suppression and role in different disease settings. We also propose several therapeutic strategies targeting Bregs for better management of immune disorders.

Adoptive cellular immunotherapy in metastatic renal cell carcinoma: a systematic review and meta-analysis

Purpose

Metastatic renal cell carcinoma (mRCC), as one of the most immunogenic tumors has been the focus of adoptive cellular immunotherapy (ACI), but the effects of ACI on objective response and survival in patients with mRCC are still controversial. Therefore, a systematic review and meta-analysis was performed to address this issue.

Methods

A search was conducted in the PubMed database for randomized clinical trials (RCTs) with ACI in mRCC. All included articles in this study were assessed according to the selection criteria and were divided into two groups: ACI versus no ACI. Outcomes were toxicity, objective response, 1-, 3- and 5-year survival. Risk ratio (RR) and 95% confidence intervals (CI) were calculated using a fixed-effects meta-analysis. Heterogeneity was measured by value of I² or P.

Results

4 studies (469 patients) were included. Most of ACI-related adverse reactions were grade 1 or 2 and reversible. ACI provided significant benefit in terms of objective response (RR = 1.65; 95% CI, 1.15 to 2.38; P = 0.007, I² = 49%), 1-year survival (RR = 1.30; 95% CI, 1.12 to 1.52; P = 0.0008, I² = 0%), 3-year survival (RR = 2.76; 95% CI, 1.85 to 4.14; P<0.00001, I² = 46%) and 5-year survival (RR = 2.42; 95% CI, 1.21 to 4.83; P = 0.01, I² = 28%).

Conclusions

ACI may be a safe and effective treatment for improving objective response, 1-, 3- and 5-year survival in patients with mRCC. Besides, five obstacles for ACI, including high degree of personalization, unsuitable WHO/RECIST response criteria, inadequate identification of tumor-associated antigens (TAAs), lack of effective combination treatments and less attention paid to the quality of ACI products, should be overcome during the successful development of more potent ACI for cancer in the future.

The future is now: chimeric antigen receptors as new targeted therapies for childhood cancer

Improved outcomes for children with cancer hinge on the development of new targeted therapies with acceptable short-term and long-term toxicity. Progress in basic, preclinical, and clinical arenas spanning cellular immunology, gene therapy, and cell-processing technologies have paved the way for clinical applications of chimeric antigen receptor-based therapies. This is a new form of targeted immunotherapy that merges the exquisite targeting specificity of monoclonal antibodies with the potent cytotoxicity, potential for expansion, and long-term persistence provided by cytotoxic T cells. Although this field is still in its infancy, clinical trials have already shown clinically significant antitumor activity in neuroblastoma, chronic lymphocytic leukemia, and B-cell lymphoma, and trials targeting a variety of other adult and pediatric malignancies are under way. Ongoing work is focused on identifying optimal tumor targets and elucidating and manipulating both cell- and host-associated factors to support expansion and persistence of the genetically engineered cells in vivo. In pediatric oncology, CD19 and GD2 are compelling antigens that have already been identified for targeting pre-B acute lymphoblastic leukemia and neuroblastoma, respectively, with this approach, but it is likely that other antigens expressed in a variety of childhood cancers will also soon be targeted using this therapy. The potential to target essentially any tumor-associated cell-surface antigen for which a monoclonal antibody can be made opens up an entirely new arena for targeted therapy of childhood cancer.

Immunology in the clinic review series; focus on cancer: double trouble for tumours: bi-functional and redirected T cells as effective cancer immunotherapies

Cancer is one of the most important pathological conditions facing mankind in the 21st century, and is likely to become the most important cause of death as improvements continue in health, diet and life expectancy. The immune response is responsible for controlling nascent cancer through immunosurveillance. If tumours escape this control, they can develop into clinical cancer. Although surgery and chemo- or radiotherapy have improved survival rates significantly, there is a drive to reharness immune responses to treat disease. As T cells are one of the key immune cells in controlling cancer, research is under way to enhance their function and improve tumour targeting. This can be achieved by transduction with tumour-specific T cell receptor (TCR) or chimaeric antigen receptors (CAR) to generate redirected T cells. Virus-specific cells can also be transduced with TCR or CAR to create bi-functional T cells with specificity for both virus and tumour. In this review we outline the development and optimization of redirected and bi-functional T cells, and outline the results from current clinical trials using these cells. From this we discuss the challenges involved in generating effective anti-tumour responses while avoiding concomitant damage to normal tissues and organs.

Identification of novel HLA-A*0201-restricted epitopes from anterior gradient-2 as a tumor-associated antigen against colorectal cancer

Anterior gradient-2 (AGR2) promotes tumor growth, cell migration and cellular transformation and its enhanced expression is almost completely restricted to malignant tissues, thus making AGR2 an interesting target for the development of immunotherapeutic strategies. We investigated whether the AGR2 molecule comprises human leukocyte antigen (HLA)-A*0201-binding epitopes recognized by human cytotoxic T lymphocytes (CTLs), which could be targeted in dendritic cell (DC)-based cancer immunotherapy against colorectal cancer (CRC). We reviewed the sequence of AGR2 for peptides that could potentially bind to HLA-A*0201 with the aid of a computer-based program. Five candidate peptides with different binding scores were synthesized and tested. These peptides were then assessed for their immunogenicity to elicit specific immune responses mediated by CTLs in vitro by means of enzyme-linked immunospot assays and CTL assays. AGR2 was highly expressed in several CRC cell lines, including DK01, DLD1, KM12C, HCT-8 and HT-29. DCs pulsed with AGR2-P2 (aa 11-19; LLVALSYTL) or AGR2-P4 (aa 127-135; RIMFVDPSL) generated potent CTLs that could lyse T2 cells pulsed with AGR2-P2 or AGR2-P4 and HLA-A0201(+) AGR2-positive CRC cell lines in a strong dose-dependent and HLA-A*0201-restricted manner. In conclusion, these novel epitopes derived from AGR2 protein may be attractive candidates for DC-based immunotherapy for CRC.

Evaluation of current cancer immunotherapy: hemato-oncology

Hematologic malignancies were the first diseases in clinical oncology for which the potential of harnessing the immune system as targeted therapy was unequivocally demonstrated. Unfortunately, the use of this highly efficacious modality has been limited to only a subset of patients and diseases because of immune-mediated toxicities resulting from incomplete specificity, and disease-specific determinants of sensitivity versus resistance to immune effector mechanisms. Recent studies, however, have begun to elucidate the molecular basis of the observed clinical effects allowing the rational development of next generation of immunotherapeutic combinations. We discuss here cancer antigen targets in hematologic malignancies and the specific approaches to induce immunity being pursued, the importance of modulating the host immunoregulatory environment, and the special features of immunological monitoring in clinical investigation. The hematologic malignancies represent an ideal setting for the development of immunotherapy due to logistical, clinical monitoring, and disease biology factors and may represent an exemplar for immune-based treatment in other cancer types.