Novel mode of action of c-kit tyrosine kinase inhibitors leading to NK cell-dependent antitumor effects

Impact of systemic steroids on the efficacy of first line imatinib treatment of patients with advanced gastrointestinal stromal tumors (GISTs)

BACKGROUND

Effective management of adverse events is required to maintain sufficient imatinib dosing when treating patients with gastrointestinal stromal tumors (GISTs). Skin rash is a common adverse event of imatinib, which can be effectively controlled by systemic steroid treatment without imatinib dose modification or interruption. However, the impact of the use of systemic steroids on the efficacy of imatinib treatment remains unclear.

METHODS

Between October 2014 and February 2022, 277 consecutive patients from a prospective registry of GIST patients were included as the study population. Patients who started systemic steroids due to grade ≥ 3 skin rash or grade 2 skin rash with grade 2 pruritis were classified as the steroid group, whereas patients who did not develop a skin rash or those who did not require steroids for a mild skin rash were classified as the control group. Efficacy outcomes were compared between the two groups.

RESULTS

Among the 277 patients, 30 (10.8%) were treated with systemic steroids for skin rash. There was no significant difference in progression free survival (PFS) or overall survival (OS) between the steroid and control groups (3-year PFS, 67.7% vs. 65.1%, p = 0.53; 3-year OS, 91% vs. 89.9%, p = 0.67, respectively). The use of systemic steroids was not an independent factor associated with PFS (hazard ratio 0.73, 95% confidence interval 0.36-1.49, p = 0.39) and OS (hazard ratio 0.37, 95% confidence interval 0.12-1.18, p = 0.09). In the steroid group, patients who successfully maintained the imatinib dosage showed a trend toward more favorable survival outcomes than those who did not (3-year PFS, 73.3% vs. 44.4%, p = 0.34; 3-year OS, 95.8% vs. 75.0%, p = 0.15, respectively).

CONCLUSIONS

The use of systemic steroids for the control of imatinib induced severe skin rash did not adversely affect the efficacy outcomes of imatinib in patients with advanced GIST.

The immunotherapy in gastrointestinal stromal tumors

Using Tyrosine Kinase Inhibitors (TKIs) for gastrointestinal stromal tumors (GIST) has significantly reduced the risk of recurrence and prolonged survival. Immunotherapy has demonstrated efficacy in multiple solid tumors, but its effectiveness in GIST remains uncertain. Although early clinical studies indicate good tolerability of immunotherapy in patients, the efficacy is not as desired. Therefore, identifying the subset of GIST patients who benefit from immunotherapy and coordinating the relationship between immunotherapy and TKI treatment are crucial issues to be explored. In this review, we aims to provide a retrospective analysis of relevant literature and find that GIST patients exhibit a rich presence of tumor-infiltrating immune cells, which play critical roles in the immune surveillance and evasion processes of tumors. This review incorporates a selection of 48 articles published between 2002 and 2023, sourced from PubMed, EBSCO, and Google Scholar databases.

Molecular characteristics and immune microenvironment of gastrointestinal stromal tumours: targets for therapeutic strategies

Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumours, arising mainly from the interstitial cells of Cajal (ICCs) of the gastrointestinal tract. As radiotherapy and chemotherapy are generally ineffective for GISTs, the current primary treatment is surgical resection. However, surgical resection is not choice for most patients. Therefore, new therapeutic strategies are urgently needed. Targeted therapy, represented by tyrosine kinase inhibitors (TKIs), and immunotherapy, represented by immune checkpoint inhibitor therapies and chimeric antigen receptor T-cell immunotherapy (CAR-T), offer new therapeutic options in GISTs and have shown promising treatment responses. In this review, we summarize the molecular classification and immune microenvironment of GISTs and discuss the corresponding targeted therapy and immunotherapy options. This updated knowledge may provide more options for future therapeutic strategies and applications in GISTs.

Potential role of immunotherapy and targeted therapy in the treatment of cancer: A contemporary nursing practice

Immunotherapy and targeted therapy have emerged as promising therapeutic options for cancer patients. Immunotherapies induce a host immune response that mediates long-lived tumor destruction, while targeted therapies suppress molecular mechanisms that are important for tumor maintenance and growth. In addition, cytotoxic agents and targeted therapies regulate immune responses, which increases the chances that these therapeutic approaches may be efficiently combined with immunotherapy to ameliorate clinical outcomes. Various studies have suggested that combinations of therapies that target different stages of anti-tumor immunity may be synergistic, which can lead to potent and more prolonged responses that can achieve long-lasting tumor destruction. Nurses associated with cancer patients should have a better understanding of the immunotherapies and targeted therapies, such as their efficacy profiles, mechanisms of action, as well as management and prophylaxis of adverse events. Indeed, this knowledge will be important in establishing care for cancer patients receiving immunotherapies and targeted therapies for cancer treatment. Moreover, nurses need a better understanding regarding targeted therapies and immunotherapies to ameliorate outcomes in patients receiving these therapies, as well as management and early detection of possible adverse effects, especially adverse events associated with checkpoint inhibitors and various other therapies that control T-cell activation causing autoimmune toxicity. Nurses practice in numerous settings, such as hospitals, home healthcare agencies, radiation therapy facilities, ambulatory care clinics, and community agencies. Therefore, as compared to other members of the healthcare team, nurses often have better opportunities to develop the essential rapport in providing effective nurse-led patient education, which is important for effective therapeutic outcomes and continuance of therapy. In this article, we have particularly focused on providing a detailed overview on targeted therapies and immunotherapies used in cancer treatment, management of their associated adverse events, and the impact as well as strategies of nurse-led patient education.

A real-world study of adjuvant anti-PD -1 immunotherapy on stage III melanoma with BRAF, NRAS, and KIT mutations

BACKGROUND

Melanoma frequently harbors BRAF, NRAS, or KIT mutations which influence both tumor development and treatment strategies. For example, it is still controversial whether adjuvant anti-PD-1 monotherapy or BRAF/MEK inhibitors may better improve the survival for resected BRAF-mutant melanoma. Furthermore, outcomes for melanoma with NRAS and KIT mutation receiving adjuvant immunotherapy remain unclear.

METHODS

One hundred seventy-four stage III melanoma patients who underwent radical surgery in Fudan University Shanghai Cancer Center (FUSCC) during January 2017 to December 2021 were included in this real-world study. Patients were followed up until death or May 30th, 2022. Pearson's chi-squared test or Fisher's exact test was performed for univariable analysis of the different category groups. Log-rank analysis was used to identify the prognostic factors for disease-free survival (DFS).

RESULTS

There were 41 (23.6%) patients with BRAF mutation, 31 (17.8%) with NRAS mutation, 17 (9.8%) with KIT mutation, and 85 (48.9%) wild-type patients without either genomic alteration of those three genes. Most ( n  = 118, 67.8%) of them were acral melanoma, while 45 (25.9%) were cutaneous subtype, and 11 were (6.3%) primary unknown. Among them, 115 (66.1%) patients received pembrolizumab or toripalimab monotherapy as adjuvant therapy; 22 (12.6%) patients received high-dose interferon (IFN), and 37 (21.3%) patients were just for observation. There was no statistical difference in clinicopathologic factors between anti-PD-1 group and IFN/OBS group. Of all the enrolled patients, anti-PD-1 group had a better DFS than IFN/OBS group ( p  = 0.039). In anti-PD-1 group, patients with BRAF or NRAS mutations had poorer DFS than wild-type group. No survival difference was found among patients harboring different gene mutations in IFN/OBS group. In wild-type patients, anti-PD-1 group had a better DFS than IFN/OBS group ( p  = 0.003), while no survival benefits were found for patients with BRAF, NRAS, or KIT mutations.

CONCLUSION

Although anti-PD-1 adjuvant therapy provides a better DFS in the general population and in wild-type patients, patients with BRAF, KIT or, especially, NRAS mutation may not benefit further from immunotherapy than conventional IFN treatment or observation.

Advances in immunology and immunotherapy for mesenchymal gastrointestinal cancers

Mesenchymal gastrointestinal cancers are represented by the gastrointestinal stromal tumors (GISTs) which occur throughout the whole gastrointestinal tract, and affect human health and economy globally. Curative surgical resections and tyrosine kinase inhibitors (TKIs) are the main managements for localized GISTs and recurrent/metastatic GISTs, respectively. Despite multi-lines of TKIs treatments prolonged the survival time of recurrent/metastatic GISTs by delaying the relapse and metastasis of the tumor, drug resistance developed quickly and inevitably, and became the huge obstacle for stopping disease progression. Immunotherapy, which is typically represented by immune checkpoint inhibitors (ICIs), has achieved great success in several solid tumors by reactivating the host immune system, and been proposed as an alternative choice for GIST treatment. Substantial efforts have been devoted to the research of immunology and immunotherapy for GIST, and great achievements have been made. Generally, the intratumoral immune cell level and the immune-related gene expressions are influenced by metastasis status, anatomical locations, driver gene mutations of the tumor, and modulated by imatinib therapy. Systemic inflammatory biomarkers are regarded as prognostic indicators of GIST and closely associated with its clinicopathological features. The efficacy of immunotherapy strategies for GIST has been widely explored in pre-clinical cell and mouse models and clinical experiments in human, and some patients did benefit from ICIs. This review comprehensively summarizes the up-to-date advancements of immunology, immunotherapy and research models for GIST, and provides new insights and perspectives for future studies.

The Prognostic Value of Plasma Programmed Death Protein-1 (PD-1) and Programmed Death-Ligand 1 (PD-L1) in Patients with Gastrointestinal Stromal Tumor

BACKGROUND

This study investigates the prognostic value of plasma Programmed Death Protein-1 (PD-1) and Programmed Death-Ligand 1 (PD-L1) concentrations in patients with Gastrointestinal Stromal Tumor (GIST).

METHODS

Patients with GIST were included (n = 157) from the two Danish sarcoma centers, independent of disease- and treatment status. The patients were divided into three subgroups; 1: patients with localized disease who underwent radical surgery; 2: patients with local, locally advanced, or metastatic disease; and 3: patients without measurable disease who had undergone radical surgery. Sensitive electrochemiluminescence immune-assays were used to determine PD-1 and PD-L1 concentration in plasma samples. The primary endpoint was the PFS.

RESULTS

No patients progressed in group 1 (n = 15), 34 progressed in group 2 (n = 122), and three progressed in group 3 (n = 20). Significantly higher plasma concentrations of PD-1 (p = 0.0023) and PD-L1 (0.012) were found in patients in group 2 compared to PD-1/PD-L1 levels in postoperative plasma samples from patient group 1. Patients with active GIST having a plasma concentration of PD-L1 above the cutoff (225 pg/mL) had a significantly poorer prognosis compared to patients with plasma PD-L1 concentration below the cutoff.

CONCLUSIONS

Plasma PD-L1 shows potential as a prognostic biomarker in patients with GIST and should be further evaluated.

NK cells and solid tumors: therapeutic potential and persisting obstacles

Natural killer (NK) cells, which are innate lymphocytes endowed with potent cytotoxic activity, have recently attracted attention as potential anticancer therapeutics. While NK cells mediate encouraging responses in patients with leukemia, the therapeutic effects of NK cell infusion in patients with solid tumors are limited. Preclinical and clinical data suggest that the efficacy of NK cell infusion against solid malignancies is hampered by several factors including inadequate tumor infiltration and persistence/activation in the tumor microenvironment (TME). A number of metabolic features of the TME including hypoxia as well as elevated levels of adenosine, reactive oxygen species, and prostaglandins negatively affect NK cell activity. Moreover, cancer-associated fibroblasts, tumor-associated macrophages, myeloid-derived suppressor cells, and regulatory T cells actively suppress NK cell-dependent anticancer immunity. Here, we review the metabolic and cellular barriers that inhibit NK cells in solid neoplasms as we discuss potential strategies to circumvent such obstacles towards superior therapeutic activity.

IL-2 Combined with IL-15 Enhanced the Expression of NKG2D Receptor on Patient Autologous NK Cells to Inhibit Wilms’ Tumor via MAPK Signaling Pathway

Objective

The dysfunction of immune surveillance, a hot spot in cancer research, could lead to the occurrence and development in multicancers. However, the potential mechanisms of immunity in Wilms' tumor (WT) remain unclear on Wilms' tumor (WT). In this study, we aim to investigate the immune cell in WT and explore the underlying treatment strategy.

Method

We quantified stromal and immune scores by using ESTIMATE algorithm based on gene expression matrix of WT patients in TCGA and GEO databases. Different expression genes (DEGs) and functional enrichments were analyzed by R studio and DAVID tools. Flow cytometry, immunofluorescence staining, ELISA assay, and qRT-PCR were used for detecting the NK cells, cytotoxic cytokines (INF-γ, PRF, and GZMB), and NK cell receptor expression, respectively. WT patient autologous NK cells were stimulated by IL-2 and IL-15, and the cytotoxicity of NK cells against WT cell lines was detected by LDH assay. Western blot experiment was used for measuring the MAPK signaling pathway protein maker in NK cells.

Results

ESTIMATE indicated that WT tissue had a lower immune score than adjacent kidney tissue. Meanwhile, the low immune score group was associated with poorly outcomes. DEG functional enrichment analysis showed that NK cell-mediated cytotoxicity was significantly different in low and high immune score groups. Although few of proportion of NK cells in WT patients were increased, most of that were significantly lower than normal children. Moreover, the proportion of NK cells and the expression level of INF-γ, PRF, and GZMB in WT tissue were lower than adjacent kidney tissue. Importantly, the NKG2D expression level of NK cells was significantly lower in WT tissue. Furthermore, in vitro, compared with uncultured NK cells, IL-2 and IL-15 could effectively enhance the cytotoxicity of NK cells on killing the WT cell lines. The FACS and WB results showed that the NKG2D and p-PI3K ratio PI3K, MEK1/2, and p-ERK1/2 ratio ERK1/2 were significantly increased in IL-2 and IL15 group compared with uncultured groups.

Conclusion

The abnormal NK cell-mediated cytotoxicity may cause the occurrence of WT. Costimulation of WT patients autologous NK cells could effectively enhance the antitumor reaction which involved in activation of NKG2D-mediated MAPK signaling pathway.

Strategies for Potentiating NK-Mediated Neuroblastoma Surveillance in Autologous or HLA-Haploidentical Hematopoietic Stem Cell Transplants

Simple Summary

High-risk neuroblastomas (HR-NB) are malignant tumors of childhood that are treated with a very aggressive and life-threatening approach; this includes autologous hemopoietic stem cell transplantation (HSCT) and the infusion of a mAb targeting the GD2 tumor-associated antigen. Although the current treatment provided benefits, the 5-year overall survival remains below 50% due to relapses and refractoriness to therapy. Thus, there is an urgent need to ameliorate the standard therapeutic protocol, particularly improving the immune-mediated anti-tumor responses. Our review aims at summarizing and critically discussing novel immunotherapeutic strategies in HR-NB, including NK cell-based therapies and HLA-haploidentical HSCT from patients’ family.

Abstract

High-risk neuroblastomas (HR-NB) still have an unacceptable 5-year overall survival despite the aggressive therapy. This includes standardized immunotherapy combining autologous hemopoietic stem cell transplantation (HSCT) and the anti-GD2 mAb. The treatment did not significantly change for more than one decade, apart from the abandonment of IL-2, which demonstrated unacceptable toxicity. Of note, immunotherapy is a promising therapeutic option in cancer and could be optimized by several strategies. These include the HLA-haploidentical αβT/B-depleted HSCT, and the antibody targeting of novel NB-associated antigens such as B7-H3, and PD1. Other approaches could limit the immunoregulatory role of tumor-derived exosomes and potentiate the low antibody-dependent cell cytotoxicity of CD16 dim/neg NK cells, abundant in the early phase post-transplant. The latter effect could be obtained using multi-specific tools engaging activating NK receptors and tumor antigens, and possibly holding immunostimulatory cytokines in their construct. Finally, treatments also consider the infusion of novel engineered cytokines with scarce side effects, and cell effectors engineered with chimeric antigen receptors (CARs). Our review aims to discuss several promising strategies that could be successfully exploited to potentiate the NK-mediated surveillance of neuroblastoma, particularly in the HSCT setting. Many of these approaches are safe, feasible, and effective at pre-clinical and clinical levels.

Next questions for the medical treatment of gastrointestinal stromal tumor

PURPOSE OF REVIEW

Since its approval in 2002, imatinib remains the standard first-line treatment for patients with advanced gastrointestinal stromal tumors (GISTs). Overall, all the drugs approved for patients who have developed secondary resistance to imatinib are less effective than imatinib in first-line. Even if, overall survival of patients with advanced GIST has improved over time the last 20 years, imatinib-resistant GIST remains therefore a difficult-to-treat cancer. The aim of this review is to elaborate on the potential strategies to improve outcome for patients with imatinib-refractory disease.

RECENT FINDINGS

New-generation potent KIT and PDGFRA inhibitors such as ripretinib and avapritinib developed for the treatment of GIST have shown very promising clinical activity in patients with highly refractory disease. However, both failed to improve outcome in comparison with standard of care in earlier lines settings. Clinical trials investigating the efficacy of multikinase inhibitor with highly specific KIT inhibitors are currently ongoing. Targeting the microenvironment of GIST may also represent a promising approach and is investigated in several clinical studies.

SUMMARY

Imatinib-refractory GIST still represent a therapeutic challenge. It is likely that only combination therapies with new generation of tyrosine kinase inhibitors (TKIs) and/or immune-oncology agents might potentially result in an enhanced therapeutic efficacy compared with current standard of care.

Trial Watch: combination of tyrosine kinase inhibitors (TKIs) and immunotherapy

The past decades witnessed the clinical employment of targeted therapies including but not limited to tyrosine kinase inhibitors (TKIs) that restrain a broad variety of pro-tumorigenic signals. TKIs can be categorized into (i) agents that directly target cancer cells, (ii) normalize angiogenesis or (iii) affect cells of the hematologic lineage. However, a clear distinction of TKIs based on this definition is limited by the fact that many TKIs designed to inhibit cancer cells have also effects on immune cells that are being discovered. Additionally, TKIs originally designed to target hematological cancers exhibit bioactivities on healthy cells of the same hematological lineage. TKIs have been described to improve immune recognition and cancer immunosurveillance, providing the scientific basis to combine TKIs with immunotherapy. Indeed, combination of TKIs with immunotherapy showed synergistic effects in preclinical models and clinical trials and some combinations of TKIs normalizing angiogenesis with immune checkpoint blocking antibodies have already been approved by the FDA for cancer therapy. However, the identification of appropriate drug combinations as well as optimal dosing and scheduling needs to be improved in order to obtain tangible progress in cancer care. This Trial Watch summarizes active clinical trials combining TKIs with various immunotherapeutic strategies to treat cancer patients.

Gastrointestinal Stromal Tumor

Over the past 20 years, gastrointestinal stromal tumor (GIST) has evolved into an increasingly complex clinical entity with ever more challenges. While surgical resection is the gold standard, advancements in genetic testing, therapeutic options, immunotherapy, and management of metastatic disease necessitate a comprehensive, multimodal approach for these tumors. This chapter highlights the importance of genomic testing of GIST, the use of neoadjuvant and adjuvant therapy for localized disease, surgical principles for GIST, as well as current and new approaches for addressing metastatic disease.

The Polarity and Specificity of Antiviral T Lymphocyte Responses Determine Susceptibility to SARS-CoV-2 Infection in Patients with Cancer and Healthy Individuals

Vaccination against coronavirus disease 2019 (COVID-19) relies on the in-depth understanding of protective immune responses to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). We characterized the polarity and specificity of memory T cells directed against SARS-CoV-2 viral lysates and peptides to determine correlates with spontaneous, virus-elicited, or vaccine-induced protection against COVID-19 in disease-free and cancer-bearing individuals. A disbalance between type 1 and 2 cytokine release was associated with high susceptibility to COVID-19. Individuals susceptible to infection exhibited a specific deficit in the T helper 1/T cytotoxic 1 (Th1/Tc1) peptide repertoire affecting the receptor binding domain of the spike protein (S1-RBD), a hotspot of viral mutations. Current vaccines triggered Th1/Tc1 responses in only a fraction of all subject categories, more effectively against the original sequence of S1-RBD than that from viral variants. We speculate that the next generation of vaccines should elicit Th1/Tc1 T-cell responses against the S1-RBD domain of emerging viral variants.

SIGNIFICANCE

This study prospectively analyzed virus-specific T-cell correlates of protection against COVID-19 in healthy and cancer-bearing individuals. A disbalance between Th1/Th2 recall responses conferred susceptibility to COVID-19 in both populations, coinciding with selective defects in Th1 recognition of the receptor binding domain of spike. See related commentary by McGary and Vardhana, p. 892. This article is highlighted in the In This Issue feature, p. 873.

Targeting oncogene and non-oncogene addiction to inflame the tumour microenvironment

Immune checkpoint inhibitors (ICIs) have revolutionized the clinical management of multiple tumours. However, only a few patients respond to ICIs, which has generated considerable interest in the identification of resistance mechanisms. One such mechanism reflects the ability of various oncogenic pathways, as well as stress response pathways required for the survival of transformed cells (a situation commonly referred to as 'non-oncogene addiction'), to support tumour progression not only by providing malignant cells with survival and/or proliferation advantages, but also by establishing immunologically 'cold' tumour microenvironments (TMEs). Thus, both oncogene and non-oncogene addiction stand out as promising targets to robustly inflame the TME and potentially enable superior responses to ICIs.

CSPG4 Expression in GIST Is Associated with Better Prognosis and Strong Cytotoxic Immune Response

Simple Summary

Gastrointestinal stromal tumors (GIST) are the most frequent sarcomas of the gastrointestinal tract. Identification of novel prognostic and/or therapeutic targets is a major issue to overcome tyrosine kinase inhibitors resistances. CSPG4, a cell surface proteoglycan, emerged as a potential therapeutic target for immune therapy in different cancers, including sarcomas. CSPG4 expression has never been studied in GIST. In this work we analyzed CSPG4 mRNA expression in a large series of clinical GIST samples given the scarcity of disease (n = 309 patients). We find that high CSPG4 expression is independently associated with disease-free survival, and with an immune landscape favorable to induce strong cytotoxic immune response after NK cell stimulation. Our results suggest the potential value of CSPG4-specific chimeric antigen receptor-redirected cytokine-induced killer lymphocytes treatment in GIST, notably “CSPG4-high” tumors, and calls for preclinical validation, drug testing in vivo, then in clinical trials.

Abstract

The treatment of gastrointestinal stromal tumors (GIST) must be improved through the development of more reliable prognostic factors and of therapies able to overcome imatinib resistance. The immune system represents an attractive tool. CSPG4, a cell surface proteoglycan, emerged as a potential therapeutic target for immune therapy in different cancers, including cell therapy based on CSPG4-specific chimeric antigen receptor (CAR)-redirected cytokine-induced killer lymphocytes (CSPG4-CAR.CIKs) in sarcomas. CSPG4 expression has never been studied in GIST. We analyzed CSPG4 mRNA expression data of 309 clinical GIST samples profiled using DNA microarrays and searched for correlations with clinicopathological and immune features. CSPG4 expression, higher in tumors than normal digestive tissues, was heterogeneous across tumors. High expression was associated with AFIP low-risk, gastric site, and localized stage, and independently with longer postoperative disease-free survival (DFS) in localized stage. The correlations between CSPG4 expression and immune signatures highlighted a higher anti-tumor immune response in “CSPG4-high” tumors, relying on both the adaptive and innate immune system, in which the boost of NK cells by CSPG4-CAR.CIKs might be instrumental, eventually combined with immune checkpoint inhibitors. In conclusion, high CSPG4 expression in GIST is associated with better DFS and offers an immune environment favorable to a vulnerability to CAR.CIKs.

Transient regulatory T-cell targeting triggers immune control of multiple myeloma and prevents disease progression

Multiple myeloma remains a largely incurable disease of clonally expanding malignant plasma cells. The bone marrow microenvironment harbors treatment-resistant myeloma cells, which eventually lead to disease relapse in patients. In the bone marrow, CD4⁺FoxP3⁺ regulatory T cells (Tregs) are highly abundant amongst CD4⁺ T cells providing an immune protective niche for different long-living cell populations, e.g., hematopoietic stem cells. Here, we addressed the functional role of Tregs in multiple myeloma dissemination to bone marrow compartments and disease progression. To investigate the immune regulation of multiple myeloma, we utilized syngeneic immunocompetent murine multiple myeloma models in two different genetic backgrounds. Analyzing the spatial immune architecture of multiple myeloma revealed that the bone marrow Tregs accumulated in the vicinity of malignant plasma cells and displayed an activated phenotype. In vivo Treg depletion prevented multiple myeloma dissemination in both models. Importantly, short-term in vivo depletion of Tregs in mice with established multiple myeloma evoked a potent CD8 T cell- and NK cell-mediated immune response resulting in complete and stable remission. Conclusively, this preclinical in-vivo study suggests that Tregs are an attractive target for the treatment of multiple myeloma.

RNA Sequence Profiling Reveals Unique Immune and Metabolic Features of Breast Cancer Brain Metastases

There is an urgent need to improve our understanding of breast cancer brain metastases (BCBMs). Thus, we obtained transcriptome data of BCBMs, primary breast cancers (BCs), and extracranial metastases (BCEMs) from the Gene Expression Omnibus (GEO) database, including GSE43837, GSE14017, and GSE14018, for immune and metabolic analysis. Firstly, we performed immune and metabolic analysis on BCBMs and primary breast cancers of GSE43837 using RNA sequence. We identified significant immunosuppression and gene signatures associated with immune infiltration in BCBMs; the lower the expression of the signatures, the worse the prognosis of breast cancer patients in the Kaplan–Meier (KM) plotter [Breast cancer] database. We also identified increased oxidative phosphorylation (OXPHOS) utilization in BCBMs compared with BCs and gene signatures associated with increased OXPHOS utilization in BCBMs; the higher the expression of the signatures, the worse the prognosis of breast cancer patients in the KM plotter [Breast cancer] database, which can predict the prognosis of breast cancer patients better, as it can also predict the prognosis of patients with different breast cancer subtypes. In addition, we performed immune and metabolic analysis on BCBMs and extracranial metastases of GSE14017 and GSE14018 using RNA sequence. Compared with extracranial metastases, we identified more significant immunosuppression but no difference in OXPHOS utilization in BCBMs, which may be because OXPHOS was also involved in extracranial metastases. We have proven that OXPHOS was functionally significant in metastasis in vitro assays. Oligomycin, an OXPHOS inhibitor, substantially attenuated the migration and invasion potential of breast cancer cells. Our study provides new insights into the pathogenesis of BCBMs.

Beyond the Driver Mutation: Immunotherapies in Gastrointestinal Stromal Tumors

Gastrointestinal stromal tumors (GISTs) are a subtype of soft tissue sarcoma (STS), and have become a concept of oncogenic addiction and targeted therapies.The large majority of these tumors develop after a mutation in KIT or platelet derived growth factor receptor α (PDGFRα), resulting in uncontrolled proliferation. GISTs are highly sensitive to imatinib. GISTs are immune infiltrated tumors with a predominance of tumor-associated macrophages (TAMs) and T-cells, including many CD8+ T-cells, whose numbers are prognostic. The genomic expression profile is that of an inhibited Th1 response and the presence of tertiary lymphoid structures and B cell signatures, which are known as predictive to response to ICI. However, the microtumoral environment has immunosuppressive attributes, with immunosuppressive M2 macrophages, overexpression of indoleamine 2,3-dioxygenase (IDO) or PD-L1, and loss of major histocompatibility complex type 1. In addition to inhibiting the KIT oncogene, imatinib appears to act by promoting cytotoxic T-cell activity, interacting with natural killer cells, and inhibiting the expression of PD-L1. Paradoxically, imatinib also appears to induce M2 polarization of macrophages. There have been few immunotherapy trials with anti-CTLA-4 or anti-PD-L1drugs and available clinical data are not very promising. Based on this comprehensive analysis of TME, we believe three immunotherapeutic strategies must be underlined in GIST. First, patients included in clinical trials must be better selected, based on the identified driver mutation (such as PDGFRα D842V mutation), the presence of tertiary lymphoid structures (TLS) or PD-L1 expression. Moreover, innovative immunotherapeutic agents also provide great interest in GIST, and there is a strong rationale for exploring IDO targeting after disease progression during imatinib therapy. Finally and most importantly, there is a strong rationale to combine of c-kit inhibition with immune checkpoint inhibitors.

Immunomodulation by targeted anticancer agents

At odds with conventional chemotherapeutics, targeted anticancer agents are designed to inhibit precise molecular alterations that support oncogenesis or tumor progression. Despite such an elevated degree of molecular specificity, many clinically employed and experimental targeted anticancer agents also mediate immunostimulatory or immunosuppressive effects that (at least in some settings) influence therapeutic efficacy. Here, we discuss the main immunomodulatory effects of targeted anticancer agents and explore potential avenues to harness them in support of superior clinical efficacy.

Chronic myeloid leukemia-from the Philadelphia chromosome to specific target drugs: A literature review

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm and was the first neoplastic disease associated with a well-defined genotypic anomaly - the presence of the Philadelphia chromosome. The advances in cytogenetic and molecular assays are of great importance to the diagnosis, prognosis, treatment, and monitoring of CML. The discovery of the breakpoint cluster region (BCR)-Abelson murine leukemia (ABL) 1 fusion oncogene has revolutionized the treatment of CML patients by allowing the development of targeted drugs that inhibit the tyrosine kinase activity of the BCR-ABL oncoprotein. Tyrosine kinase inhibitors (known as TKIs) are the standard therapy for CML and greatly increase the survival rates, despite adverse effects and the odds of residual disease after discontinuation of treatment. As therapeutic alternatives, the subsequent TKIs lead to faster and deeper molecular remissions; however, with the emergence of resistance to these drugs, immunotherapy appears as an alternative, which may have a cure potential in these patients. Against this background, this article aims at providing an overview on CML clinical management and a summary on the main targeted drugs available in that context.

Immune modulation by molecular cancer targets and targeted therapies: Rationale for novel combination strategies

Following our recent observation that alterations of the Natural Killer (NK) cell compartment in the presence of BCR-ABL-induced myeloproliferation fail to revert under targeted therapy, we discuss by what mechanisms oncogenic molecular pathways and their pharmacological inhibition may interfere with immune functions. Rational combinations of molecularly targeted and immunological strategies may provide a means for more effective cancer targeting.

Adenovirus-engineered human dendritic cells induce natural killer cell chemotaxis via CXCL8/IL-8 and CXCL10/IP-10

Recombinant adenovirus-engineered dendritic cells (Ad.DC) are potent vaccines for induction of anti-viral and anti-cancer T cell immunity. The effectiveness of Ad.DC vaccines may depend on the newly described ability of Ad.DC to crosstalk with natural killer (NK) cells via cell-to-cell contact, and to mediate activation, polarization and bridging of innate and adaptive immunity. For this interaction to occur in vivo, Ad.DC must be able to attract NK cells from surrounding tissues or peripheral blood. We developed a novel live mouse imaging system-based NK-cell migration test, and demonstrated for the first time that human Ad.DC induced directional migration of human NK cells across subcutaneous tissues, indicating that Ad.DC-NK cell contact and interaction could occur in vivo. We examined the mechanism of Ad.DC-induced migration of NK cells in vitro and in vivo. Ad.DC produced multiple chemokines previously reported to recruit NK cells, including immunoregulatory CXCL10/IP-10 and proinflammatory CXCL8/IL-8. In vitro chemotaxis experiments utilizing neutralizing antibodies and recombinant human chemokines showed that CXCL10/IP-10 and CXCL8/IL-8 were critical for Ad.DC-mediated recruitment of CD56^hiCD16^- and CD56^loCD16⁺ NK cells, respectively. The importance of CXCL8/IL-8 was further demonstrated in vivo. Pretreatment of mice with the neutralizing anti-CXCL8/IL-8 antibody led to significant inhibition of Ad.DC-induced migration of NK cells in vivo. These data show that Ad.DC can recruit spatially distant NK cells toward a vaccine site via specific chemokines. Therefore, an Ad.DC vaccine can likely induce interaction with endogenous NK cells via transmembrane mediators, and consequently mediate Th1 polarization and amplification of immune functions in vivo.

NK cells sense tumors, course of disease and treatments: Consequences for NK-based therapies

The recent findings on NK activation indicate that these cells are important antitumor effectors. NK cells participate in the graft-vs.-leukemia effect to control the relapse in leukemic patients transplanted with allogeneic hematopoietic stem cells. In various tumors, correlation between NK cell infiltrates and prognosis were reported. However, tumor-infiltrating NK cells are yet poorly characterized. We here summarize our results and the recent studies of the literature on tumor-infiltrating NK cells, and discuss the impact of these novel insights into NK cell responses against tumors for the design of NK cell-based therapies.

Nivolumab plus regorafenib in patients with small bowel adenocarcinoma: A case report

INTRODUCTION

Small bowel adenocarcinomas (SBAs) are rare cancers that have a distinct clinical characteristic and genetic profile. The only potentially curative treatment for localized SBAs is surgery, and treatment options are limited for patients in the advanced stage of disease.

PATIENT CONCERNS

A 39-year-old woman presented in October 2015 with a complaint of persistent vomiting for 8 months.

DIAGNOSIS

The patient had obstruction caused by a 3 × 2 cm mass at the ascending part of the duodenum and suspected metastasis in the right adnexal region. Postoperative pathology showed a moderately differentiated adenocarcinoma with serosal invasion. The diagnosis was stage IV duodenum adenocarcinoma with right adnexal metastasis.

INTERVENTIONS

After the failure of multi-line treatment with chemotherapy and targeted therapy, she was treated with the immune checkpoint inhibitor nivolumab plus regorafenib.

OUTCOMES

Disease control lasted for 15 months with markedly improved symptoms.

CONCLUSION

To the best of our knowledge, this is the first case of small bowel adenocarcinoma that has been treated with nivolumab combined with regorafenib. This case highlights the potential efficacy of combining nivolumab and regorafenib in the treatment of SBAs.

Translating Knowledge About the Immune Microenvironment of Gastrointestinal Stromal Tumors into Effective Clinical Strategies

OPINION STATEMENT

The role of targeted therapy is firmly established for gastrointestinal stromal tumors (GISTs); other modalities for targeting this disease are necessary for recurrent and refractory disease. There are several lines of evidence pointing to an active role of the immune system in GIST. Preclinical and clinical studies revealed that the most common type of immune cell infiltration in GISTs is tumor-associated macrophages (TAMs). The mechanism of how TAMs sculpt the tumor microenvironment in GIST is not clear, but it seems that the presence of immunosuppressive regulatory T cells (Tregs) is correlated with the number of TAMs, thus linking macrophages to immunosuppression. CD3+ T cells and NK infiltrates are found in the GIST microenvironment and carry some prognostic value. In early clinical trials, there is evidence for an active role for immunotherapy in treating GIST patients. Moreover, preclinical evidence has indicated that combining TKIs with checkpoint blockers may be synergistic in murine GIST models. Overall, there is substantial preclinical and clinical evidence to support a role for immunoregulation in GIST and further studies will be important for the development of immunotherapies for GIST.

New drugs in gastrointestinal stromal tumors

PURPOSE OF REVIEW

Tyrosine kinase inhibitors (TKIs) are the backbone for advanced gastrointestinal stromal tumor (GIST) treatment. The increasing knowledge concerning the structure and the changing conformational status because of some mutations in KIT and PDGFRα, allowed the development of new efficient compounds, with the main goal to overcome resistance in GIST. This review summarizes the latest developments in the treatment of GIST patients.

RECENT FINDINGS

Amongst the several TKIs currently being studied in GIST, ripretinib, avapritinib and crenolanib had shown promising potent activity in preclinical studies and clinical trials. Ripretinib is a type II inhibitor that exerts its main action in the switch pocket of the activation loop, by mimicking the inhibition exerted by the regulatory region in this domain. Ripretinib is considered the new standard in the fourth line in advanced GIST. Avapritinib is a type I inhibitor synthesized to exerts its activity in the active conformation of the activation loop of KIT and PDFGRα. The relevant activity reported with avapritinib in patients carrying the D842 v mutation represents, for first time, an active therapeutic option in this resistant mutant. Crenolanib is a type I selective inhibitor of PDGFRα-resistant mutants, mainly D842 V, which is currently under clinical trial.

SUMMARY

New potent TKIs are being approved, adding value to the already three registered drugs. Other agents, such as MEK inhibitors, immunotherapy and TRK-targeted therapy are potential new options in specific subsets of GIST patients.

The Role of Natural Killer (NK) Cells in Acute Coronary Syndrome: A Comprehensive Review

With poor outcomes and an immense financial burden, acute coronary syndrome (ACS) and its ischemic repercussions still present a major global health problem. Unfavorable outcomes seem to be mainly due to adverse cardiac remodeling. Since the inflammatory response takes an important role in remodeling secondary to myocardial infarction (MI), and as inflammation in this manner has not been completely elucidated, we attempted to give rise to a further understanding of ACS pathophysiology. Hence, in this review, we integrated current knowledge of complex communication networks between natural killer (NK) cells and immune and resident heart cells in the context of ACS. Based on available data, the role of NK cells seems to be important in the infarcted myocardium, where it affects heart remodeling. On the other hand, in atherosclerotic plaque, NK cells seem to be mere passers-by, except in the case of chronic infections by atherogenic pathogens. In that case, NK cells seem to support proinflammatory milieu. NK cell research is challenging due to ethical reasons, convergent evolution, and phenotypic diversity among individuals. Therefore, we argue that further research of NK cells in ACS is valuable, given their therapeutic potential in improving postischemic heart remodeling.

NK cells in the tumor microenvironment: Prognostic and theranostic impact. Recent advances and trends

NK cells orchestrate the tumor destruction and control metastasis in a coordinated way with other immune cells of the tumor microenvironment. However, NK cell infiltration in the tumor microenvironment is limited, and tumor cells have developed numerous mechanisms to escape NK cell attack. As a result, NK cells that have been able to infiltrate the tumors are exhausted, and metabolically and functionally impaired. Depending this impairment the prognostic and theranostic values of NK cells differ depending on the studies, the type of cancer, the stage of tumor and the nature of the tumor microenvironment. Extensive studies have been done to investigate different strategies to improve the NK cell function, and nowadays, a battery of therapeutic tools are being tested, with promising results.

Lymphocyte to monocyte ratio-based nomogram for predicting outcomes of hepatocellular carcinoma treated with sorafenib

BACKGROUND

The ability of the pretreatment lymphocyte to monocyte ratio (LMR) to predict outcomes of patients with hepatocellular carcinoma (HCC) receiving sorafenib is not conclusively determined.

METHODS

We retrospectively studied patients treated with sorafenib for HCC in two tertiary referral centres in Asia and North America. Primary endpoints were overall survival (OS) and progression-free survival (PFS). Predictive factors for the outcomes were determined by Cox proportional hazards models. A risk assessment tool was developed.

RESULTS

Compared to the North America cohort, the Asia cohort was more heavily pretreated (72.1% vs. 35.2%; p < 0.001), had higher hepatitis B virus infection (87.6% vs. 5.6%; p < 0.001), and more distant metastases (83.2% vs. 25.4%; p < 0.001). Lower monocyte count in the Asia cohort (median 462.7 vs. 600.0/μL; p = 0.023) resulted in a higher LMR (median 2.6 vs. 1.8; p < 0.001). High LMR was associated with a significantly higher OS [hazard ratio (HR) 0.88; 95% confidence interval (CI) 0.81‒0.97; p = 0.007]. This was confirmed in a sensitivity analysis including patients treated in Asia only (HR 0.89; 95% CI 0.81‒0.97; p = 0.010). An OS nomogram was constructed with the following variables selected in the multivariate Cox model: LMR, treatment location, previous treatment, performance status, alpha-fetoprotein, lymph node metastasis, and Child‒Pugh score. The concordance score was 0.71 (95% CI, 0.67‒0.75). LMR did not predict PFS.

CONCLUSION

LMR measured before sorafenib administration predicts OS in advanced HCC patients. Our OS nomogram, incorporating LMR, can be offered to clinicians to improve their ability to assess prognosis, strengthen the prognosis-based decision-making, and inform patients in the clinic.

Phase I study of vinblastine in combination with nilotinib in children, adolescents, and young adults with refractory or recurrent low-grade glioma

Background

New rescue regimens are needed for pediatric refractory/recurrent low-grade glioma. Nilotinib is a tyrosine kinase inhibitor that has potential synergistic effects with vinblastine on angiogenesis, tumor cell growth, and immunomodulation.

Methods

This phase I trial aimed to determine the recommended doses of this combination for phase II trials (RP2D) using the dual-agent Bayesian continual reassessment method. Nilotinib was given orally twice daily (BID) in combination with once-weekly vinblastine injections for a maximum of 12 cycles of 28 days (clinicaltrials.gov, NCT01884922).

Results

Thirty-five pediatric patients were enrolled across 4 dose levels. The median age was 7 years and 10 had neurofibromatosis type 1. Patients had received a median of 3 prior treatment lines and 25% had received more than 4 previous treatment lines. Dose-limiting toxicity (DLT) during cycle 1 was hematologic, dermatologic, and cardiovascular. The RP2D was identified at 3 mg/m² weekly for vinblastine with 230 mg/m² BID for nilotinib (estimated probability of DLT = 18%; 95% credibility interval, 7-29%). Fifteen patients completed the 12 cycles; 2 stopped therapy prematurely due to toxicity and 18 due to disease progression. Three patients achieved a partial response leading to an objective response rate of 8.8% (95% confidence interval [CI], 1.9-23.7), and the disease control rate was 85.3% (95% CI, 68.9-95.1). The 12-month progression-free survival was 37.1% (95% CI, 23.2-53.67).

Conclusions

Vinblastine and nilotinib combination was mostly limited by myelosuppression and dermatologic toxicity. The efficacy of the combination at the RP2D is currently evaluated in a randomized phase II trial comparing this regimen to vinblastine alone.

Immune-infiltration based signature as a novel prognostic biomarker in gastrointestinal stromal tumour

BACKGROUND

Accumulating evidence indicates that tumour-infiltrating lymphocytes (TILs) are the primary determinant of survival outcomes in various tumours. Thus, we sought to investigate the TIL distribution and density in gastrointestinal stromal tumours (GISTs) and to develop an immune infiltration (II)-based signature to predict prognosis.

METHODS

The expression of 8 immune features in the tumour centre (TC) and tumour margin (TM) and PD-L1 in 435 GIST patients was investigated by immunohistochemistry. Then, a 4-feature-based II-GIST signature integrating the CD3⁺ TC, CD3⁺ TM, CD8⁺ TM and CD45RO⁺ TM parameters was developed using a LASSO Cox regression model in the training cohort and was validated in two separate validation cohorts.

FINDINGS

High CD3⁺ TC, CD3⁺ TM, CD8⁺ TC, CD8⁺ TM, CD45RO⁺ TM, NKp46⁺ TM and CD20⁺ TM correlated with improved survival. Patients with high II-GIST scores have better RFS and OS outcomes than those with low II-GIST scores. Multivariable analyses demonstrated that the II-GIST signature is an independent prognostic factor. The receiver operating characteristic (ROC) curve demonstrated that the prognostic accuracy of the II-GIST signature is superior to that of the NIH risk criteria. Further analysis showed that moderate- and high-risk GIST patients with high II-GIST scores could gain survival benefits from adjuvant imatinib therapy.

INTERPRETATION

The novel II-GIST signature accurately predicted the survival outcomes of GIST patients. In addition, the II-GIST signature was a useful predictor of survival benefit from imatinib therapy amongst moderate- and high-risk patients with GIST.

FUNDING

This project was supported by National Natural Science Foundation of China (81702325), Natural Science Foundation of Guangdong Province (2017A030310565), and 3&3 Project of the First Affiliated Hospital of Sun Yat-sen University.

Phase I trial evaluating safety and efficacy of intratumorally administered inflammatory allogeneic dendritic cells (ilixadencel) in advanced gastrointestinal stromal tumors

Background

The majority of patients with advanced gastrointestinal stromal tumor (GIST) develop resistance to imatinib, and subsequent treatments have limited efficacy. Ilixadencel (allogeneic inflammatory dendritic cells) is a cell-based immune primer injected intratumorally that previously has been clinically investigated in metastatic renal cell carcinoma and hepatocellular carcinoma.

Methods

The trial was a single arm phase I trial assessing safety and efficacy of ilixadencel in subjects with progressing advanced/metastatic GIST despite ongoing treatment with second or later lines of tyrosine kinase inhibitors (TKI). Three patients were progressing while on sunitinib (second line), one on regorafenib (third line), and two on pazopanib (fourth line). TKI treatment was maintained throughout, while two intratumoral injections of ilixadencel (10 × 10⁶ viable and HLA-DR expressing cells per dose) were administered.

Results

No severe adverse events were found to be related to ilixadencel administration. Four patients showed continued tumor progression at 3 months per RECIST 1.1 and Choi criteria. One patient (on third line regorafenib) had stable disease for 9 months and another patient (on second line sunitinib) had stable disease at end of study (12 months) as per RECIST 1.1. These two patients developed a partial response as per Choi criteria with a duration of 3 and 6 months, respectively. The median progression-free survival (PFS) was 4.0 months.

Conclusion

Ilixadencel treatment presented an acceptable safety profile among advanced GIST patients who developed resistance to TKI. Encouraging radiological tumor responses were detected in 33% of treated patients, supporting further investigation.

Clinical trial registrationwww.clinicaltrials.gov; NCT: 02432846; registration date: February 22, 2016.

Electronic supplementary material

The online version of this article (10.1007/s00262-020-02625-5) contains supplementary material, which is available to authorized users.

Flow cytometry and targeted immune transcriptomics identify distinct profiles in patients with chronic myeloid leukemia receiving tyrosine kinase inhibitors with or without interferon-α

Background

Tumor cells have evolved complex strategies to escape immune surveillance, a process which involves NK cells and T lymphocytes, and various immunological factors. Indeed, tumor cells recruit immunosuppressive cells [including regulatory T-cells (Treg), myeloid-derived suppressor cells (MDSC)] and express factors such as PD-L1. Molecularly targeted therapies, such as imatinib, have off-target effects that may influence immune function. Imatinib has been shown to modulate multiple cell types involved in anti-cancer immune surveillance, with potentially detrimental or favorable outcomes. Imatinib and other tyrosine kinase inhibitors (TKIs) in chronic myeloid leukemia (CML) have dramatically changed disease course. Our study aimed to characterize the different populations of the immune system in patients with CML affected by their treatment.

Methods

Forty-one patients with CML [33 treated with TKIs and 8 with TKIs plus interferon (IFN)-α] and 20 controls were enrolled in the present study. Peripheral blood populations of the immune system [referred to as the overview of immune system (OVIS) panel, Treg cells and MDSCs] and PD-1 expression were evaluated by flow cytometry. The immunological profile was assessed using the mRNA Pan-Cancer Immune Profiling Panel and a NanoString nCounter FLEX platform.

Results

Patients receiving combination therapy (TKIs + IFN-α) had lower numbers of lymphocytes, particularly T cells [838/µL (95% CI 594–1182)] compared with healthy controls [1500/µL (95% CI 1207 – 1865), p = 0.017]. These patients also had a higher percentage of Treg (9.1%) and CD4⁺PD-1⁺ cells (1.65%) compared with controls [Treg (6.1%) and CD4⁺/PD-1⁺(0.8%); p ≤ 0.05]. Moreover, patients treated with TKIs had more Mo-MDSCs (12.7%) whereas those treated with TKIs + IFN-α had more Gr-MDSC (21.3%) compared to controls [Mo-MDSC (11.4%) and Gr-MDSC (8.48%); p ≤ 0.05]. CD56^bright NK cells, a cell subset endowed with immune-regulatory properties, were increased in patients receiving TKIs plus IFN-α compared with those treated with TKIs alone. Interestingly, serum IL-21 was significantly lower in the TKIs plus IFN-α cohort. Within the group of patients treated with TKI monotherapy, we observed that individuals receiving 2nd generation TKIs had lower percentages of CD4⁺ Treg (3.63%) and Gr-MDSC (4.2%) compared to patients under imatinib treatment (CD4⁺ Treg 6.18% and Gr-MDSC 8.2%), but higher levels of PD-1-co-expressing CD4⁺ cells (1.92%).

Conclusions

Our results suggest that TKIs in combination with IFN-α may promote an enhanced immune suppressive state.

ABCC3 Expressed by CD56dim CD16+ NK Cells Predicts Response in Glioblastoma Patients Treated with Combined Chemotherapy and Dendritic Cell Immunotherapy

Recently, we found that temozolomide (TMZ) can upregulate the expression of the multidrug-resistance protein ABCC3 in NK cells from both glioma-bearing mice and glioblastoma patients treated with dendritic cell immunotherapy combined with TMZ, allowing NK cells to escape apoptosis and favoring their role as antitumor effector cells. Here, we demonstrate that CD56^dim NK cells expressing CD16⁺ are predominant in patients surviving more than 12 months after surgery without disease progression. CD56^dim CD16⁺ NK cells co-expressed high levels of ABCC3 and IFN-γ. Notably, not only basal but also TMZ-induced ABCC3 expression was related to a strong, long-term NK cell response and a better prognosis of patients. The identification of the single nucleotide polymorphism (SNP) rs35467079 with the deletion of a cytosine (−897DelC) in the promoter region of the ABCC3 gene resulted associated with a better patient outcome. ABCC3 expression in patients carrying DelC compared to patients with reference haplotype was higher and modulated by TMZ. The transcription factor NRF2, involved in ABCC3 induction, was phosphorylated in CD56^dim CD16⁺ NK cells expressing ABCC3 under TMZ treatment. Thus, ABCC3 protein and the SNP −897DelC can play a predictive role in patients affected by GBM, and possibly other cancers, treated with dendritic cell immunotherapy combined with chemotherapy.

Cyclophosphamide, Fluorouracil and subcutaneous Interleukin-2 in the treatment of advanced GIST: A Case Report

A male 68 years hold patient was admitted to surgical ward for hemorrhagic shock. After CT scan detection of 6x5 cm neoformation of first jejunal loop, he was submitted to segmental resection and pathological diagnosis was gastrointestinal stromal tumor. The patient was defined as high-risk according to Takahashi criteria, but refused Imatinib adjuvant therapy. After 15 months of disease-free interval, he developed bilobar liver metastases. After treatment with Imatinib 400 mg he reported G3 hepatotoxicity resolved with temporary suspension, he continue low dose with stable disease. After liver progression, he resumed Imatinib full dose with disease stabilization for 9 months. After liver progression, second line Sunitinib 37,5 mg/day was started for four months with stable disease. After further liver and lymph node mediastinal progression he was treated for four months with Regorafenib with disease stabilization. Patient developed slow but inexorable progression of liver disease with severe abdominal pain resistant to opioid and was treated with authorized compassionate program comprising Cyclophosphamide 300 mg/sqm and Fluorouracil 500 mg/sqm on day 1 intravenously followed by Interleukin-2 4.5 MUI subcutaneously on days 3–6 and 17–20 every four weeks. After three cycles the patients obtained a relevant subjective improvement with partial response on mediastinal lymph node and liver stabilization. A substantial increase on neutrophil, lymphocytes, monocytes, platelets, T regulator cells count, and a decrease on platelets/lymphocytes, CD8/T regulator cells ratio, CD8, NK count and C-reactive protein value were observed after treatment compared to basal value. The toxicity was mild represented by fever G1, flue-like-syndrome G1 during the treatment. After four cycle of chemo-immunotherapy, the patient demonstrated progression of disease and died five months after treatment. Noteworthy is the temporal disease control with significant symptomatic improvement achieved for the first time with this chemo-immunotherapeutic combination in a patient with very advanced pretreated GIST.

Immune microenvironment profiling of gastrointestinal stromal tumors (GIST) shows gene expression patterns associated to immune checkpoint inhibitors response

Few studies were conducted investigating the immunological profiles in gastrointestinal stromal tumors (GIST). Adaptive and innate immune cells are present in the tumor microenvironment, indicating GIST as inflamed tumors. In addition, murine models suggested a potential interaction between immune components and imatinib. In this retrospective study, the GIST immunological profile was investigated through in silico analysis and immunohistochemistry (IHC), exploring the basis for immunotherapy approaches. Gene expression profiles (GEP) from 31 KIT/PDGFRA-mutant GIST were analyzed to evaluate the tumor microenvironment and immunotherapy predictive signatures such as the expanded IFN-γ-induced immune signature (EIIS) and the T-cell-inflamed signature (TIS). GEP and IHC supported the presence of immune infiltrate in GIST, with dominance of CD4+ and CD8+ T cells and M2 macrophages showing a remarkable similarity with melanoma microenvironment. The EIIS genes were expressed in most of GIST samples and positively correlated with PD-L1 abundance (p < .0001). Co-expression was also found between PD-L1 and CD8A (p < .0001) or CD8B (p = .0003). Moreover, the median TIS score for GIST was between the 65th and 70th percentile of the Cancer Genome Atlas dataset, in the same range of tumors responding to anti-PD-1/PD-L1. Analysis of the Gene Expression Omnibus database GIST samples pre- and post-treatment confirmed that imatinib downregulates PD-L1 and IRF1 expression through the inhibition of KIT and PDGFRA, thus contributing to counteract the suppressed adaptive immune response against GIST. The presence of a rich immune infiltrate in GIST along with the presence of TIS and EIIS suggests that GIST may benefit from immunotherapy along with tyrosine kinase inhibitors.

KIT as an Oncogenic Driver in Melanoma: An Update on Clinical Development

Metastatic melanoma is a heterogenous disease that has served as a model for the development of both targeted therapy and immunotherapy. KIT-mutated melanoma represents a rare subset, most commonly arising from acral, mucosal, and chronically sun-damaged skin. Additionally, KIT alterations are enriched in the triple wild-type subtype of cutaneous melanoma. Activating alterations of KIT-a transmembrane receptor tyrosine kinase important for cell development, growth, and differentiation-have been shown to be critical to oncogenesis across many tumor subtypes. Following the successes of BRAF-targeted therapy in melanoma and KIT-targeted therapy in gastrointestinal stromal tumors, small-molecule tyrosine kinase inhibitors targeting KIT have been examined in KIT-mutated melanoma. KIT inhibitors that have been investigated in relevant clinical trials in advanced melanoma include imatinib, sunitinib, dasatinib, and nilotinib. In these studies, selected patients with KIT-mutated melanoma were shown to be responsive to therapy with KIT inhibition, especially patients with L576P and K642E mutations. This has led to the incorporation of KIT-targeted therapy in the National Comprehensive Cancer Network guidelines for systemic therapy for metastatic or unresectable melanoma. Current research and development efforts include novel KIT-targeted therapies and testing KIT inhibitors in combination with immunotherapy.

Strategies to Improve Cancer Immune Checkpoint Inhibitors Efficacy, Other Than Abscopal Effect: A Systematic Review

Despite that the impact of immune checkpoint inhibitors on malignancies treatment is unprecedented, a lack of response to these molecules is observed in several cases. Differently from melanoma and non-small cell lung cancer, where the use of immune checkpoint inhibitors results in a high efficacy, the response rate in other tumors, such as gastrointestinal cancers, breast cancer, sarcomas, and part of genitourinary cancers remains low. The first strategy evaluated to improve the response rate to immune checkpoint inhibitors is the use of predictive factors for the response such as PD-L1 expression, tumor mutational burden, and clinical features. In addition to the identification of the patients with a higher expression of immune checkpoint molecules, another approach currently under intensive investigation is the use of therapeutics in a combinatory manner with immune checkpoint inhibitors in order to obtain an enhancement of efficacy through the modification of the tumor immune microenvironment. In addition to the abscopal effect induced by radiotherapy, a lot of studies are evaluating several drugs able to improve the response rate to immune checkpoint inhibitors, including microbiota modifiers, drugs targeting co-inhibitory receptors, anti-angiogenic therapeutics, small molecules, and oncolytic viruses. In view of the rapid and extensive development of this research field, we conducted a systematic review of the literature identifying which of these drugs are closer to achieving validation in the clinical practice.

Crizotinib-induced immunogenic cell death in non-small cell lung cancer

Immunogenic cell death (ICD) converts dying cancer cells into a therapeutic vaccine and stimulates antitumor immune responses. Here we unravel the results of an unbiased screen identifying high-dose (10 µM) crizotinib as an ICD-inducing tyrosine kinase inhibitor that has exceptional antineoplastic activity when combined with non-ICD inducing chemotherapeutics like cisplatin. The combination of cisplatin and high-dose crizotinib induces ICD in non-small cell lung carcinoma (NSCLC) cells and effectively controls the growth of distinct (transplantable, carcinogen- or oncogene induced) orthotopic NSCLC models. These anticancer effects are linked to increased T lymphocyte infiltration and are abolished by T cell depletion or interferon-γ neutralization. Crizotinib plus cisplatin leads to an increase in the expression of PD-1 and PD-L1 in tumors, coupled to a strong sensitization of NSCLC to immunotherapy with PD-1 antibodies. Hence, a sequential combination treatment consisting in conventional chemotherapy together with crizotinib, followed by immune checkpoint blockade may be active against NSCLC.

Certain chemotherapeutic agents can exert their anticancer effect through indirect immune-dependent mechanism. Here, the authors screen a library of tyrosine kinase inhibitors and show that crizotinib is an effective stimulator of immunogenic cell death and can potentiate the efficacy of immune checkpoint blockade.

Immunogenic chemotherapy: Dose and schedule dependence and combination with immunotherapy

Conventional cytotoxic cancer chemotherapy is often immunosuppressive and associated with drug resistance and tumor regrowth after a short period of tumor shrinkage or growth stasis. However, certain cytotoxic cancer chemotherapeutic drugs, including doxorubicin, mitoxantrone, and cyclophosphamide, can kill tumor cells by an immunogenic cell death pathway, which activates robust innate and adaptive anti-tumor immune responses and has the potential to greatly increase the efficacy of chemotherapy. Here, we review studies on chemotherapeutic drug-induced immunogenic cell death, focusing on how the choice of a conventional cytotoxic agent and its dose and schedule impact anti-tumor immune responses. We propose a strategy for effective immunogenic chemotherapy that employs a modified metronomic schedule for drug delivery, which we term medium-dose intermittent chemotherapy (MEDIC). Striking responses have been seen in preclinical cancer models using MEDIC, where an immunogenic cancer chemotherapeutic agent is administered intermittently and at an intermediate dose, designed to impart strong and repeated cytotoxic damage to tumors, and on a schedule compatible with activation of a sustained anti-tumor immune response, thereby maximizing anti-cancer activity. We also discuss strategies for combination chemo-immunotherapy, and we outline approaches to identify new immunogenic chemotherapeutic agents for drug development.

Benign T cells drive clinical skin inflammation in cutaneous T cell lymphoma

Psoralen plus UVA (PUVA) is an effective therapy for mycosis fungoides (MF), the skin-limited variant of cutaneous T cell lymphoma (CTCL). In low-burden patients, PUVA reduced or eradicated malignant T cells and induced clonal expansion of CD8+ T cells associated with malignant T cell depletion. High-burden patients appeared to clinically improve but large numbers of malignant T cells persisted in skin. Clinical improvement was linked to turnover of benign T cell clones but not to malignant T cell reduction. Benign T cells were associated with the Th2-recruiting chemokine CCL18 before therapy and with the Th1-recruiting chemokines CXCL9, CXCL10, and CXCL11 after therapy, suggesting a switch from Th2 to Th1. Inflammation was correlated with OX40L and CD40L gene expression; immunostaining localized these receptors to CCL18-expressing c-Kit+ dendritic cells that clustered together with CD40+OX40+ benign and CD40+CD40L+ malignant T cells, creating a proinflammatory synapse in skin. Our data suggest that visible inflammation in CTCL results from the recruitment and activation of benign T cells by c-Kit+OX40L+CD40L+ dendritic cells and that this activation may provide tumorigenic signals. Targeting c-Kit, OX40, and CD40 signaling may be novel therapeutic avenues for the treatment of MF.

Updated clinical and biological information from the two-stage phase II study of imatinib mesylate in subjects with relapsed/refractory neuroblastoma

Several studies support the notion that the kinase inhibitor Imatinib mesylate exerts off-target effects on cells of the immune system. After our first report of continuous daily oral administration in subjects with relapsed/refractory neuroblastoma (NB, EudraCT: 2005-005778-63), here we update the clinical information and report additional information on potential surrogate markers for prediction of efficacy. Peripheral blood (PB) samples collected at study entry and after the first and second cycle of Imatinib mesylate treatment were tested for IFN-γ, TNF-α, TGF-β, IL-10, CXCL12 and soluble (s) B7-H6 plasma levels. In addition, paired PB and bone marrow (BM) samples collected at study entry and after the second Imatinib cycle were evaluated for CXCL12, CXCR4 and NKp30 isoform mRNA levels. Correlation between each parameter level and response/outcome was then evaluated. Out of the six subjects still alive at the time of the first report, thee died after additional therapy, two for NB progression and one for a second malignancy. Three are presently alive and cured from NB at 10 years after the first Imatinib cycle. Of these, one achieved complete response (CR) during Imatinib treatment and never relapsed, one had a local relapse removed by surgery and the third received TVD as rescue therapy. Response and outcome were associated with low Imatinib exposure, whereas none of the tested immunological and molecular parameters was predictive of response/outcome. However, after Imatinib treatment NKp30 isoform mRNA levels significantly increase in BM samples, indicating that Imatinib mesylate exerted an off-target effect on NK cells in vivo. Imatinib mesylate efficacy in relapsed/refractory NB has been confirmed at a longer follow-up, supporting its inclusion in new Phase II trials for these subjects, that should envisage collection of samples to evaluate the predictive power of other potential surrogate markers of efficacy.

The renaissance of anti-neoplastic immunity from tumor cell demise

Cancer therapies can temporarily reduce tumor burdens by inducing malignant cell death. However, cancer cure is still far from realization because tumors often gain resistance to current treatment and eventually relapse. Accumulating evidence suggests that successful cancer interventions require anti-tumor immunity. Therapy-induced cell stress responses ultimately result in one or more cell death modalities, including apoptosis, autophagy, necroptosis, and pyroptosis. These irreversible dying processes are accompanied by active or passive release of cell death-associated molecular patterns (CDAMPs), which can be sensed by corresponding pattern recognition receptors (PRR) on tumor-infiltrating immune cells. This crosstalk with the immune system can reawaken immune surveillance in the tumor microenvironment (TME). This review focuses on immune-modulatory properties of anti-cancer regimens and CDAMP-mediated communications between cell stress responses and the immune contexture of TME. In addition, we describe how immunogenic cell death can elicit strong and durable anti-tumor immune responses.

Regulation of mTOR, Metabolic Fitness, and Effector Functions by Cytokines in Natural Killer Cells

The control of cellular metabolism is now recognized as key to regulate functional properties of immune effectors such as T or Natural Killer (NK) cells. During persistent infections or in the tumor microenvironment, multiple metabolic changes have been highlighted in T cells that contribute to their dysfunctional state or exhaustion. NK cells may also undergo major phenotypic and functional modifications when infiltrating tumors that could be linked to metabolic alterations. The mammalian target of rapamycin (mTOR) kinase is a central regulator of cellular metabolism. mTOR integrates various extrinsic growth or immune signals and modulates metabolic pathways to fulfill cellular bioenergetics needs. mTOR also regulates transcription and translation thereby adapting cellular pathways to the growth or activation signals that are received. Here, we review the role and regulation of mTOR in NK cells, with a special focus on cytokines that target mTOR such as IL-15 and TGF-β. We also discuss how NK cell metabolic activity could be enhanced or modulated to improve their effector anti-tumor functions in clinical settings.

Harness the synergy between targeted therapy and immunotherapy: what have we learned and where are we headed?

Since the introduction of imatinib for the treatment of chronic myelogenous leukemia, several oncogenic mutations have been identified in various malignancies that can serve as targets for therapy. More recently, a deeper insight into the mechanism of antitumor immunity and tumor immunoevasion have facilitated the development of novel immunotherapy agents. Certain targeted agents have the ability of inhibiting tumor growth without causing severe lymphocytopenia and amplifying antitumor immune response by increasing tumor antigenicity, enhancing intratumoral T cell infiltration, and altering the tumor immune microenvironment, which provides a rationale for combining targeted therapy with immunotherapy. Targeted therapy can elicit dramatic responses in selected patients by interfering with the tumor-intrinsic driver mutations. But in most cases, resistance will occur over a relatively short period of time. In contrast, immunotherapy can yield durable, albeit generally mild, responses in several tumor types via unleashing host antitumor immunity. Thus, combination approaches might be able to induce a rapid tumor regression and a prolonged duration of response. We examine the available evidence regarding immune effects of targeted therapy, and review preclinical and clinical studies on the combination of targeted therapy and immunotherapy for cancer treatment. Furthermore, we discuss challenges of the combined therapy and highlight the need for continued translational research.

Combined KIT and CTLA-4 Blockade in Patients with Refractory GIST and Other Advanced Sarcomas: A Phase Ib Study of Dasatinib plus Ipilimumab

Purpose: A phase Ib study of dasatinib plus ipilimumab in patients with gastrointestinal stromal tumor (GIST) and other sarcomas was performed on the basis of preclinical data demonstrating that combined KIT and CTLA-4 blockade is synergistic.Experimental Design: A standard 3 + 3 design was used to evaluate the safety, efficacy, and immune correlates of treatment. Dose escalation cohorts received ipilimumab 10 or 3 mg/kg every 3 weeks, followed by maintenance every 12 weeks with escalating doses of dasatinib (70 mg daily, 100 mg daily, or 70 mg twice daily). Response was assessed by RECIST 1.1, Choi, and immune-related RECIST criteria (irRC).Results: A total of 28 patients (17 male) were enrolled. Histologic subtypes included GISTs (n = 20) and other sarcomas (n = 8.) Dasatinib 70 mg/day with ipilimumab 10 mg/kg or dasatinib 140 mg/day with ipilimumab 3 mg/kg can be safely administered. Dose-limiting toxicities included grade 3 gastric hemorrhage and anemia. No partial or complete responses were noted by RECIST or irRC. There were 7 of 13 partial responses in the GIST patients by Choi criteria, and 3 of 13 patients each had stable and progressive disease, respectively.Conclusions: Dasatinib and ipilimumab can be safely administered to GIST and sarcoma patients. However, dasatinib was not synergistic with ipilimumab, as there was limited clinical efficacy with the combination. This limited cohort provides prospective data that indoleamine-2,3-dioxygenase (IDO) suppression may potentially correlate with antitumor efficacy in GIST. Given the small cohort, it is only hypothesis generating and additional data would be required. In the era of more modern and effective checkpoint inhibitors, next steps could be consideration of tyrosine kinase inhibitors or IDO inhibitors in combination with anti-PD-1 therapy. Clin Cancer Res; 23(12); 2972-80. ©2016 AACR.

Targeting natural killer cells in cancer immunotherapy

Alteration in the expression of cell-surface proteins is a common consequence of malignant transformation. Natural killer (NK) cells use an array of germline-encoded activating and inhibitory receptors that scan for altered protein-expression patterns, but tumor evasion of detection by the immune system is now recognized as one of the hallmarks of cancer. NK cells display rapid and potent immunity to metastasis or hematological cancers, and major efforts are now being undertaken to fully exploit NK cell anti-tumor properties in the clinic. Diverse approaches encompass the development of large-scale NK cell-expansion protocols for adoptive transfer, the establishment of a microenvironment favorable to NK cell activity, the redirection of NK cell activity against tumor cells and the release of inhibitory signals that limit NK cell function. In this Review we detail recent advances in NK cell-based immunotherapies and discuss the advantages and limitations of these strategies.

Immunotherapeutic properties of chemotherapy

Impressive remissions driven by immunological checkpoint blockade in cancer patients have prompted the scientific community to investigate afresh the crosstalk between cancer cells and the patient's immune system. Preclinical and clinical studies have highlighted that the anticancer efficacy of some conventional chemotherapeutics is based on their ability to restore anticancer immune responses. The current challenge is to understand and circumvent immune resistance mechanisms to chemo- and immunotherapies to design relevant immunotherapy and chemotherapy combinations. In this review, we will summarize which immunological processes are involved in the anticancer action of some cytotoxic agents and discuss the recently unraveled contribution of the gut microbiota into the immunogenicity of anticancer drugs. We will eventually introduce the scientific rationale for therapeutic strategies combining chemotherapeutic drugs and immune checkpoint blockers.