Gene and virotherapy for hematological malignancies

Combining Oncolytic Viruses with Chimeric Antigen Receptor T Cell Therapy

Chimeric antigen receptor (CAR) T cell therapy has revolutionized the treatment of hematological malignancies, but solid tumors continue to pose significant challenges. Oncolytic viruses (OVs) have generated significant excitement in the field of cancer treatment recently. In particular, OVs can help CAR T cells overcome some of the immunosuppressive mechanisms within the tumor microenvironment through OV intrinsic effects or delivery of immunostimulatory agents. Numerous preclinical studies demonstrate that combining CAR T cells with OVs can increase CAR T cell trafficking, antitumor activity, and elimination of antigen-negative tumor cells. Despite promising preclinical results, only one clinical trial (NCT03740256) investigating CAR T and OV combination therapy is underway, highlighting the challenges of translating this approach to the clinic. Antiviral immunity and the route of OV administration, in addition to concerns about cost and safety, limit the clinical application of this approach. Strategies to reduce the production cost of both CAR T cells and OVs, as well as molecularly modifying OVs to enhance their bioavailability, will likely encourage further exploration of this combination therapy in clinical trials.

Antibody-Based Immunotherapeutic Strategies for the Treatment of Hematological Malignancies

As the most common type of cancer in the world, hematological malignancies (HM) account for 10% of all annual cancer deaths and have attracted more attention. Conventional treatments, such as chemotherapy, radiotherapy, and hematopoietic stem cell transplantation (HSCT), could relieve patients suffering HM. However, serious side effects and high costs bring patients both physical complaints and mental pressure. Recently, compared with conventional therapeutic strategies for HM patients, antibody-based immunotherapies, including cancer vaccines, oncolytic virus therapies, monoclonal antibody treatments, and CAR-T cell therapies, have displayed longer survival time and fewer adverse reactions, even though specific efficacy and safety of these antibody-based immunotherapies still need to be evaluated and improved. This review summarized the advantages of antibody-based immunotherapies over conventional treatments, as well as its existing difficulties and solutions, thereby enhancing the understanding and applications of antibody-based immunotherapies in HM treatment.

Mesenchymal stem cells as carrier of the therapeutic agent in the gene therapy of blood disorders

Nonhematopoietic stem cells as a delivery platform of therapeutic useful genes have attracted widespread attention in recent years, owing to gained a long lifespan, easy separation, high proliferation, and high transfection capacity. Mesenchymal stem/stromal cells (MSCs) are the choice of the cells for gene and cell therapy due to high self-renewal capacity, high migration rate to the site of the tumor, and with immune suppressive and anti-inflammatory properties. Hence, it has a high potential of safety genetic modification of MSCs for antitumor gene expression and has paved the way for the clinical application of these cells to target the therapy of cancers and other diseases. The aim of gene therapy is targeted treatment of cancers and diseases through recovery, change, or enhancement cell performance to the sustained secretion of useful therapeutic proteins and induction expression of the functional gene in intended tissue. Recent developments in the vectors designing leading to the increase and durability of expression and improvement of the safety of the vectors that overcome a lot of problems, such as durability of expression and the host immune response. Nowadays, gene therapy approach is used by MSCs as a delivery vehicle in the preclinical and the clinical trials for the secretion of erythropoietin, recombinant antibodies, coagulation factors, cytokines, as well as angiogenic inhibitors in many blood disorders like anemia, hemophilia, and malignancies. In this study, we critically discuss the status of gene therapy by MSCs as a delivery vehicle for the treatment of blood disorders. Finally, the results of clinical trial studies are assessed, highlighting promising advantages of this emerging technology in the clinical setting.

The Oncolytic Virotherapy Era in Cancer Management: Prospects of Applying H-1 Parvovirus to Treat Blood and Solid Cancers

Non-Hodgkin lymphoma (NHL) and leukemia are among the most common cancers worldwide. While the treatment of NHL/leukemia of B-cell origin has much progressed with the introduction of targeted therapies, few treatment standards have been established for T-NHL/leukemia. As presentation in both B- and T-NHL/leukemia patients is often aggressive and as prognosis for relapsed disease is especially dismal, this cancer entity poses major challenges and requires innovative therapeutic approaches. In clinical trials, oncolytic viruses (OVs) have been used against refractory multiple myeloma (MM). In preclinical settings, a number of OVs have demonstrated a remarkable ability to suppress various types of hematological cancers. Most studies dealing with this approach have used MM or B- or myeloid-cell-derived malignancies as models. Only a few describe susceptibility of T-cell lymphoma/leukemia to OV infection and killing. The rat H-1 parvovirus (H-1PV) is an OV with considerable promise as a novel therapeutic agent against both solid tumors (pancreatic cancer and glioblastoma) and hematological malignancies. The present perspective article builds on previous reports of H-1PV-driven regression of Burkitt's lymphoma xenografts and on unpublished observations demonstrating effective killing by H-1PV of cells from CHOP-resistant diffuse large B-cell lymphoma, cutaneous T-cell lymphoma, and T-cell acute lymphoblastic leukemia. On the basis of these studies, H-1PV is proposed for use as an adjuvant to (chemo)therapeutic regimens. Furthermore, in the light of a recently completed first parvovirus clinical trial in glioblastoma patients, the advantages of H-1PV for systemic application are discussed.