Preclinical immunotherapy with Cytokine-Induced Killer lymphocytes against epithelial ovarian cancer

CSPG4 CAR-redirected Cytokine Induced Killer lymphocytes (CIK) as effective cellular immunotherapy for HLA class I defective melanoma

BACKGROUND

Even acknowledging the game-changing results achieved in the treatment of metastatic melanoma with the use of immune checkpoint inhibitors (ICI), a large proportion of patients (40-60%) still fail to respond or relapse due to the development of resistance. Alterations in the expression of Human Leukocyte Antigen class I (HLA-I) molecules are considered to play a major role in clinical resistance to ICI. Cellular immunotherapy with HLA-independent CAR-redirected lymphocytes is a promising alternative in this challenging setting and dedicated translational models are needed.

METHODS

In this study, we propose an HLA-independent therapeutic strategy with Cytokine Induced Killer lymphocytes (CIK) genetically engineered with a Chimeric Antigen Receptor (CAR) targeting the tumor antigen CSPG4 as effector mechanism. We investigated the preclinical antitumor activity of CSPG4-CAR.CIK in vitro and in a xenograft murine model focusing on patient-derived melanoma cell lines (Mel) with defective expression of HLA-I molecules.

RESULTS

We successfully generated CSPG4-CAR.CIK from patients with metastatic melanoma and reported their intense activity in vitro against a panel of CSPG4-expressing patient-derived Mel. The melanoma killing activity was intense, even at very low effector to target ratios, and not influenced by the expression level (high, low, defective) of HLA-I molecules on target cells. Furthermore, CAR.CIK conditioned medium was capable of upregulating the expression of HLA-I molecules on melanoma cells. A comparable immunomodulatory effect was replicated by treatment of Mel cells with exogenous IFN-γ and IFN-α. The antimelanoma activity of CSPG4-CAR.CIK was successfully confirmed in vivo, obtaining a significant tumor growth inhibition of an HLA-defective Mel xenograft in immunodeficient mice.

CONCLUSIONS

In this study we reported the intense preclinical activity of CSPG4-CAR.CIK against melanoma, including those with low or defective HLA-I expression. Our findings support CSPG4 as a valuable CAR target in melanoma and provide translational rationale for clinical studies exploring CAR-CIK cellular immunotherapies within the challenging setting of patients not responsive or relapsing to immune checkpoint inhibitors.

Clinical Applications of Combined Immunotherapy Approaches in Gastrointestinal Cancer: A Case-Based Review

Malignant neoplasms arising from the gastrointestinal (GI) tract are among the most common types of cancer with high mortality rates. Despite advances in treatment in a small subgroup harboring targetable mutations, the outcome remains poor, accounting for one in three cancer-related deaths observed globally. As a promising therapeutic option in various tumor types, immunotherapy with immune checkpoint inhibitors has also been evaluated in GI cancer, albeit with limited efficacy except for a small subgroup expressing microsatellite instability. In the quest for more effective treatment options, energetic efforts have been placed to evaluate the role of several immunotherapy approaches comprising of cancer vaccines, adoptive cell therapies and immune checkpoint inhibitors. In this review, we report our experience with a personalized dendritic cell cancer vaccine and cytokine-induced killer cell therapy in three patients with GI cancers and summarize current clinical data on combined immunotherapy strategies.

How can Cytokine-induced killer cells overcome CAR-T cell limits

The successful treatment of patients affected by B-cell malignancies with Chimeric Antigen Receptor (CAR)-T cells represented a breakthrough in the field of adoptive cell therapy (ACT). However, CAR-T therapy is not an option for every patient, and several needs remain unmet. In particular, the production of CAR-T cells is expensive, labor-intensive and logistically challenging; additionally, the toxicities deriving from CAR-T cells infusion, such as cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS), have been documented extensively. Alternative cellular therapy products such as Cytokine-induced killer (CIK) cells have the potential to overcome some of these obstacles. CIK cells are a heterogeneous population of polyclonal CD3+CD56+ T cells with phenotypic and functional properties of NK cells. CIK cell cytotoxicity is exerted in a major histocompatibility complex (MHC)-unrestricted manner through the engagement of natural killer group 2 member D (NKG2D) molecules, against a wide range of hematological and solid tumors without the need for prior antigen exposure or priming. The foremost potential of CIK cells lies in the very limited ability to induce graft-versus-host disease (GvHD) reactions in the allogeneic setting. CIK cells are produced with a simple and extremely efficient expansion protocol, which leads to a massive expansion of effector cells and requires a lower financial commitment compared to CAR-T cells. Indeed, CAR-T manufacturing involves the engineering with expensive GMP-grade viral vectors in centralized manufacturing facilities, whereas CIK cell production is successfully performed in local academic GMP facilities, and CIK cell treatment is now licensed in many countries. Moreover, the toxicities observed for CAR-T cells are not present in CIK cell-treated patients, thus further reducing the costs associated with hospitalization and post-infusion monitoring of patients, and ultimately encouraging the delivery of cell therapies in the outpatient setting. This review aims to give an overview of the limitations of CAR-T cell therapy and outline how the use of CIK cells could overcome such drawbacks thanks to their unique features. We highlight the undeniable advantages of using CIK cells as a therapeutic product, underlying the opportunity for further research on the topic.

Comparison of cytotoxic potency between freshly cultured and freshly thawed cytokine-induced killer cells from human umbilical cord blood

Immune cell therapy has been incorporated into cancer therapy over the past few years. Chimeric antigen receptor T cells (Car-T cells) transplantation is a novel and promising therapy for cancer treatment and introduces a new age of immune cell therapy. However, the expensive nature of genetic modification procedures limits the accessibility of Car-T cells for cancer treatment. Cytokine-induced killer cells (CIKs) can kill the target cells in an MHC-non-restricted manner; these cells can be developed to "off-the-shelf" immune cell products for cancer treatment. However, the anti-tumor potency of freshly thawed CIKs is not well documented. This study aimed to fill this gap, evaluating the anti-tumor potency of freshly thawed CIKs compared to that of freshly cultured CIKs. CIKs were produced from the human umbilical cord blood in accordance with published protocols. CIKs were cryopreserved in xeno-free cryomedium that contains 5% DMSO, 10% human serum in phosphate buffer saline at - 86 °C. These cells were thawed and immediately utilized in assays (called freshly thawed CIKs) with freshly cultured cells are control. The expression of the surface markers of CIKs, cytokine production, and in vitro anti-tumor cytotoxic cells of freshly thawed CIKs were evaluated and compared to freshly cultured CIKs. Additionally, the freshly thawed CIKs were injected into the breast of tumor-bearing mice to assess the anti-tumor potency in vivo. The results obtained in freshly thawed CIKs and freshly cultured CIKs demonstrated that the expression of CD3, and CD56 were comparable in both cases. The production of TNF-α, IFN-γ, and IL-10 was slightly reduced in freshly thawed cells compared to the freshly cultured cells. The in vitro lysis toward MCF-7 cancer cells was similar between freshly thawed and freshly cultured CIKs. Moreover, the freshly thawed CIKs displayed anti-breast tumor activity in the breast tumor-bearing mice. The volume of tumors significantly reduced in the mice grafted with freshly thawed CIKs while, conversely, the tumor volume in mice of the placebo group gradually increased. This study substantiated that freshly thawed CIKs preserved their anti-tumor potency in both in vitro and in vivo conditions. The results initially revealed the great potential of UCB-CIKs for "off-the-shelf" CIK product manufacturing. However, further studies on the effects of cryomedia, freezing rate, and thawing procedure should be undertaken before freshly thawed off-the-shelf UCB-CIKs are utilized in clinical trials.

Patient-Derived In Vitro Models of Ovarian Cancer: Powerful Tools to Explore the Biology of the Disease and Develop Personalized Treatments

Epithelial ovarian cancer (OC) is the most lethal gynecological malignancy worldwide due to a late diagnosis caused by the lack of specific symptoms and rapid dissemination into the peritoneal cavity. The standard of care for OC treatment is surgical cytoreduction followed by platinum-based chemotherapy. While a response to this frontline treatment is common, most patients undergo relapse within 2 years and frequently develop a chemoresistant disease that has become unresponsive to standard treatments. Moreover, also due to the lack of actionable mutations, very few alternative therapeutic strategies have been designed as yet for the treatment of recurrent OC. This dismal clinical perspective raises the need for pre-clinical models that faithfully recapitulate the original disease and therefore offer suitable tools to design novel therapeutic approaches. In this regard, patient-derived models are endowed with high translational relevance, as they can better capture specific aspects of OC such as (i) the high inter- and intra-tumor heterogeneity, (ii) the role of cancer stem cells (a small subset of tumor cells endowed with tumor-initiating ability, which can sustain tumor spreading, recurrence and chemoresistance), and (iii) the involvement of the tumor microenvironment, which interacts with tumor cells and modulates their behavior. This review describes the different in vitro patient-derived models that have been developed in recent years in the field of OC research, focusing on their ability to recapitulate specific features of this disease. We also discuss the possibilities of leveraging such models as personalized platforms to design new therapeutic approaches and guide clinical decisions.

Blood microbiota diversity determines response of advanced colorectal cancer to chemotherapy combined with adoptive T cell immunotherapy

Human microbiota influence the response of malignancies to treatment with immune checkpoint blockade; however, their impact on other forms of immunotherapy is poorly understood. This study explored the effect of blood microbiota on clinical efficacy, represented by progression-free survival (PFS) and overall survival (OS), of combined chemotherapy and adoptive cellular therapy (ACT) in advanced colon cancer patients. Plasma was collected from colorectal cancer patients (CRC) treated with either chemotherapy alone (oxaliplatin and capecitabine) (XELOX CT alone group, n = 19), or ACT with a mixed dendritic cell/cytokine-induced killer cell product (DC-CIK) + XELOX (ICT group, n = 20). Circulating microbiota analysis was performed by PCR amplification and next-generation sequencing of variable regions V3~V4 of bacterial 16S rRNA genes. The association of the blood microbial diversity with clinical response to the therapy as measured by RECIST1.1 and OS was evaluated. The baseline Chao index of blood microbial diversity predicted prolonged PFS and OS of DC/CIK immunotherapy. More diverse blood microbiota that included Bifidobacterium, Lactobacillus, and Enterococcus were identified among responders to DC/CIK compared with non-responders. The plasma bacterial DNA copy number is inversely correlated with the CD3-/CD16+/CD56+ NK cells in circulation and decreased following DC-CIK; however, the Chao index of plasma microbiota significantly increased after administration of the DC-CIK product and this subsequent change was correlated with the number of CD3-/CD16+/CD56+ and CD8+/CD28+ cells infused. The diversity of the blood microbiome is a promising predictive marker for clinical responses to chemotherapy combined with DC-CIK. Cellular immunotherapy can affect the plasma microbiota's diversity in a manner favorable to clinical responses.

Immunotherapy for platinum-resistant ovarian cancer

Ovarian cancer is characterized by a high mortality on incidence ratio. Although the majority of patients achieve complete response after primary treatment, approximately 65-80% of patients recur with the first 5 years. Platinum-free interval is one of the main prognostic factors. Patients recurring with 6 months within the end of platinum-based chemotherapy are characterized by poor prognosis. To date no effective treatment modality are identified for those patients. The mainstay of treatment for platinum-resistant ovarian cancer is single agent chemotherapy. Other treatment modalities have tested in this setting with discouraging results. Growing evidence suggested that immunotherapy would improve outcomes of patients with various types of solid tumors including melanoma, non-small cell lung cancer as well as uterine malignancies. Here, we reviewed current evidence on the adoption of immunotherapy in platinum-resistant ovarian cancer. To date no mature evidence supports the routine adoption of immunotherapy in ovarian cancer patients. Further strategies have to be explored.