Cancer immune therapy for lymphoid malignancies: recent advances

Immune Infiltration in Gastric Cancer Microenvironment and Its Clinical Significance

Immunotherapy has developed rapidly and has gradually become one of the important methods for treatment of gastric cancer (GC). The research on tumor infiltrating immune cells (TIICs) and immune-related genes in the tumor microenvironment (TME) greatly encourages the development of immunotherapy. The devolution algorithm (CIBERSORT) was applied to infer the proportion of 22 TIICs based on gene expression profiles of GC tissues, which were downloaded from TCGA and GEO. TCGA was utilized to analyze the differential expression of immune-related genes, and explore the potential molecular functions of these genes. We have observed the enrichment of multiple TIICs in microenvironment of GC. Some of these cells were closely related to tumor mutational burden (TMB), microsatellite instability (MSI), Fuhrman grade, and TNM staging. Survival analysis showed that the infiltration level of CD8+ T cells, activated CD4+ memory T cells and M2 macrophages were significantly related to the prognosis of GC patients. The functional enrichment analysis of immune-related genes revealed that these genes were mainly associated with cytokine activation and response. Four significant modules were screened by PPI network and 20 key genes were screened from the modules. The expression levels of CALCR and PTH1R are strikingly related to the expression of immune checkpoint and the prognosis of GC patients. The type and number of TIICs in microenvironment of GC, as well as immune-related genes are closely related to tumor progression, and can be used as important indicators for patient prognosis assessment.

An immunogenic first-in-human immune modulatory vaccine with PD-L1 and PD-L2 peptides is feasible and shows early signs of efficacy in follicular lymphoma

Cells in the tumor microenvironment of Follicular lymphoma (FL) express checkpoint molecules such as programmed death ligands 1 and 2 (PD-L1 and PD-L2) and are suppressing anti-tumor immune activity. Stimulation of peripheral blood mononuclear cells (PBMC) with PD-L1 (IO103) or PD-L2 (IO120) peptides can activate specific T cells inducing anti-regulatory functions including cytotoxicity against PD-L1/PD-L2-expressing cells. In this study, we vaccinated eight FL patients with PD-L1 and PD-L2 peptides following treatment with standard chemotherapy. Patients experienced grade 1-2 injection site reaction (5/8) and mild flu-like symptoms (6/8). One patient experienced neutropenia and thrombocytopenia during pseudo-progression. Enzyme-linked immunospot detected vaccine-specific immune responses in PBMC from all patients, predominately toward PD-L1. The circulating immune composition was stable during treatment; however, we observed a reduction regulatory T cells, however, not significant. One patient achieved a complete remission during vaccination and two patients had pseudo-progression followed by long-term disease regression. Further examination of these early signs of clinical efficacy of the dual-epitope vaccine in a larger study is warranted.

Chimeric antigen receptor therapy in hematological malignancies: antigenic targets and their clinical research progress

Chimeric antigen receptor (CAR)-based immunotherapy has achieved dramatic success in the treatment of B cell malignancies, based on the summary of current research data, and has shown good potential in early phase cancer clinical trials. Modified constructs are being optimized to recognize and destroy tumor cells more effectively. By targeting the proper B-lineage-specific antigens such as CD19 and CD20, adoptive immunotherapy has demonstrated promising clinical results and already plays a role in the treatment of several lymphoid malignancies, which highlights the importance of target selection for other CAR therapies. The high efficacy of CAR-T cells has resulted in the approval of anti-CD19-directed CAR-T cells for the treatment of B cell malignancies. In this review, we focus on the basic structure and current clinical application of CAR-T cells, detail the research progress of CAR-T for different antigenic targets in hematological malignancies, and further discuss the current barriers and proposed solutions, investigating the possible mechanisms of recurrence of CAR-T cell therapy. A summary of the paper is also given to overview as the prospects for this therapy.

The current reality of soft tissue sarcomas: advances, controversies, areas for improvement, and promising new treatments

Introduction: Soft tissue sarcomas (STS) encompass a group of rare and heterogeneous cancers. Rapid evolution in the field justifies a focused critical review of the clinical literature.Areas covered: Important advances, and associated controversies, in managing patients with STS are reviewed by treatment setting, histopathological subtype, and general management considerations. Despite many advances, opportunities remain to improve care to benefit patients. Areas of sarcoma research showing early promise indicate that new treatment development requires a deeper understanding of the biological characteristics of unique histotypes, with a focus on targeting sarcoma-relevant oncogenic driver mechanisms.Expert opinion: Mandatory treatment of sarcoma patients in reference centers represents a simple and cost-effective means of improving survival as the knowledge generated through international collaboration can be implemented sooner to improve patient outcomes. Sarcoma complexity complicates clinical trial designs in both peri-operative and advanced treatment settings. Future trials in front-line therapy in advanced situations should enroll patients based on the goal of therapy - tumor shrinkage or palliation - using appropriate endpoints to evaluate benefit. Global collaboration remains key to identifying the most appropriate patients and concepts to test in well-designed and accessible clinical trials. The sarcoma community shares a common desire that standard treatments will be established based on molecular profiling within the next five to 10 years.

Direct-acting antivirals in relapsed or refractory hepatitis C virus-associated diffuse large B-cell lymphoma

Recent studies have demonstrated feasibility and substantial benefit of direct-acting antivirals (DAAs) administration during or after first-line immune-chemotherapy (I-CT) in patients with hepatitis C virus (HCV)-positive diffuse large B-cell lymphomas (DLBCL). However, data on DAAs used during or after salvage treatments are still lacking. In this study we assessed clinical and virological outcome in 11 patients with relapsed (n = 7) or refractory (n = 4) HCV-positive DLBCL. DAAs were given either concurrently (n = 3) or subsequent (n = 8) to salvage I-CT. Most patients (10 of 11) received sofosbuvir-based regimens. All patients completed their planned courses of DAAs and achieved sustained virological response. DAAs were well tolerated, with no grade ≥2 adverse events. At a median follow-up of 3.6 years four patients died (4-year OS: 76%). In conclusion, we provide evidence that DAAs in HCV-positive relapsed/refractory DLBCL are extremely safe and effective, suggesting that they should be used if HCV eradication was not instituted before.

A novel targeted GPC3/CD3 bispecific antibody for the treatment hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most frequent primary liver cancer but has shown limited success to date in the treatment of advanced stage. Recruitment of T cells for cancer treatment is a rapidly growing strategy in immunotherapy such as chimeric antigen receptor T cells and bispecific antibodies. However, unwanted aggregations, structural instability or short serum half-life are major challenges of bispecific antibodies. Here, we developed a new format of T cell-redirecting antibody that is bispecific for membrane proteoglycans GPC3 of HCC and the T-cell-specific antigen CD3, which demonstrated to be favorable stability and productivity. Cross-linking of T cells with GPC3 positive tumor cells by the anti-GPC3/CD3 bispecific antibody-mediated potent GPC3-dependent and concentration-dependent cytotoxicity in vitro. Administration of the bispecific antibody with different concentrations in murine xenograft models of human HCC significantly inhibited tumor growth. In addition, no effects on tumor growth were observed in the absence of human effector cells or the bispecific antibody. Taken together, the anti-GPC3/CD3 bispecific antibody might be a potential therapeutic treatment for HCC.

How to Train Your T Cells: Overcoming Immune Dysfunction in Multiple Myeloma

The progression of multiple myeloma, a hematologic malignancy characterized by unregulated plasma cell growth, is associated with increasing innate and adaptive immune system dysfunction, notably in the T-cell repertoire. Although treatment advances in multiple myeloma have led to deeper and more durable clinical responses, the disease remains incurable for most patients. Therapeutic strategies aimed at overcoming the immunosuppressive tumor microenvironment and activating the host immune system have recently shown promise in multiple myeloma, particularly in the relapsed and/or refractory disease setting. As the efficacy of T-cell-dependent immuno-oncology therapy is likely affected by the health of the endogenous T-cell repertoire, these therapies may also provide benefit in alternate treatment settings (e.g., precursor disease; after stem cell transplantation). This review describes T-cell-associated changes during the evolution of multiple myeloma and provides an overview of T-cell-dependent immuno-oncology approaches under investigation. Vaccine and checkpoint inhibitor interventions are being explored across the multiple myeloma disease continuum; treatment modalities that redirect patient T cells to elicit an anti-multiple myeloma response, namely, chimeric antigen receptor (CAR) T cells and bispecific antibodies [including BiTE (bispecific T-cell engager) molecules], have been primarily evaluated to date in the relapsed and/or refractory disease setting. CAR T cells and bispecific antibodies/antibody constructs directed against B-cell maturation antigen have generated excitement, with clinical data demonstrating deep responses. An increased understanding of the complex interplay between the immune system and multiple myeloma throughout the disease course will aid in maximizing the potential for T-cell-dependent immuno-oncology strategies in multiple myeloma.

Genetically engineered T cells for cancer immunotherapy

T cells in the immune system protect the human body from infection by pathogens and clear mutant cells through specific recognition by T cell receptors (TCRs). Cancer immunotherapy, by relying on this basic recognition method, boosts the antitumor efficacy of T cells by unleashing the inhibition of immune checkpoints and expands adaptive immunity by facilitating the adoptive transfer of genetically engineered T cells. T cells genetically equipped with chimeric antigen receptors (CARs) or TCRs have shown remarkable effectiveness in treating some hematological malignancies, although the efficacy of engineered T cells in treating solid tumors is far from satisfactory. In this review, we summarize the development of genetically engineered T cells, outline the most recent studies investigating genetically engineered T cells for cancer immunotherapy, and discuss strategies for improving the performance of these T cells in fighting cancers.

Humanized mouse models of immunological diseases and precision medicine

With the increase in knowledge resulting from the sequencing of the human genome, the genetic basis for the underlying differences in individuals, their diseases, and how they respond to therapies is starting to be understood. This has formed the foundation for the era of precision medicine in many human diseases that is beginning to be implemented in the clinic, particularly in cancer. However, preclinical testing of therapeutic approaches based on individual biology will need to be validated in animal models prior to translation into patients. Although animal models, particularly murine models, have provided significant information on the basic biology underlying immune responses in various diseases and the response to therapy, murine and human immune systems differ markedly. These fundamental differences may be the underlying reason why many of the positive therapeutic responses observed in mice have not translated directly into the clinic. There is a critical need for preclinical animal models in which human immune responses can be investigated. For this, many investigators are using humanized mice, i.e., immunodeficient mice engrafted with functional human cells, tissues, and immune systems. We will briefly review the history of humanized mice, the remaining limitations, approaches to overcome them and how humanized mouse models are being used as a preclinical bridge in precision medicine for evaluation of human therapies prior to their implementation in the clinic.

T cell-redirecting bispecific antibodies in cancer immunotherapy: recent advances

PURPOSE

Globally, cancer is a critical illness which seriously threatens human health. T-cell-based cancer immunotherapy for some patients has demonstrated impressive achievements including chimeric antigen receptor T cells, immune checkpoint inhibitors and T cell-redirecting bispecific antibodies (TRBAs). TRBAs recruit T cells to lyse cancer cells bypassing the antigen presentation through the major histocompatibility complex pathways. In this review we summarized the TRBAs formats, biophysical characteristics, the preclinical and clinical trial results, as well as the challenges faced by TRBAs in tumour therapy.

METHODS

Herein the relevant literature and clinical trials from the PubMed and ClinicalTrials.gov database.

RESULTS

The advances in protein engineering technology have generated diverse TRBAs format which can be classified into two categories: IgG-like TRBAs and non-IgG-like TRBAs. Multiple applications of TRBAs showed encouraging curative effect and entered clinical trials for lymphoid malignancy and solid tumour.

CONCLUSIONS

TRBA is a powerful tool for the cancer treatment and the clinical studies showed potent anti-tumour efficacy in hematologic malignancies. Although the clinical outcomes of TRBAs in solid tumours are less satisfied than hematologic malignancies, many preclinical antibodies and combination therapies are being evaluated.

Epidemiology, outcome, targeted agents and immunotherapy in adolescent and young adult non-Hodgkin and Hodgkin lymphoma

The epidemiology, outcome and targeted immunotherapy in adolescent and young adult non-Hodgkin and Hodgkin lymphoma were discussed during the 6th International Symposium on Childhood, Adolescent and Young Adult Non-Hodgkin Lymphoma September 26th-29th 2018 in Rotterdam, the Netherlands. This review summarizes some of those presentations, as well as other current and novel antibody therapy, immune check-point inhibitors, chimeric antigen receptor T cells, cancer vaccines and cytotoxic T lymphocyte therapy.