Old-School Chemotherapy in Immunotherapeutic Combination in Cancer, A Low-cost Drug Repurposed

Cyclophosphamide augments the efficacy of in situ vaccination in a mouse melanoma model

Introduction

We have previously shown that an intratumoral (IT) injection of the hu14.18-IL2 immunocytokine (IC), an anti-GD2 antibody linked to interleukin 2, can serve as an in situ vaccine and synergize with local radiotherapy (RT) to induce T cell-mediated antitumor effects. We hypothesized that cyclophosphamide (CY), a chemotherapeutic agent capable of depleting T regulatory cells (Tregs), would augment in situ vaccination. GD2+ B78 mouse melanoma cells were injected intradermally in syngeneic C57BL/6 mice.

Methods

Treatments with RT (12Gy) and/or CY (100 mg/kg i.p.) started when tumors reached 100-300 mm3 (day 0 of treatment), followed by five daily injections of IT-IC (25 mcg) on days 5-9. Tumor growth and survival were followed. In addition, tumors were analyzed by flow cytometry.

Results

Similar to RT, CY enhanced the antitumor effect of IC. The strongest antitumor effect was achieved when CY, RT and IC were combined, as compared to combinations of IC+RT or IC+CY. Flow cytometric analyses showed that the combined treatment with CY, RT and IC decreased Tregs and increased the ratio of CD8+ cells/Tregs within the tumors. Moreover, in mice bearing two separate tumors, the combination of RT and IT-IC delivered to one tumor, together with systemic CY, led to a systemic antitumor effect detected as shrinkage of the tumor not treated directly with RT and IT-IC. Cured mice developed immunological memory as they were able to reject B78 tumor rechallenge.

Conclusion

Taken together, these preclinical results show that CY can augment the antitumor efficacy of IT- IC, given alone or in combination with local RT, suggesting potential benefit in clinical testing of these combinations.

EphA4 signaling is involved in the phenotype of well-differentiated oral squamous cell arcinoma with decreased tumor immunity

Metronomic chemotherapy is defined as a high-frequency low-dose schedule of chemotherapy drug administration. Although metronomic chemotherapy is widely used, the mechanisms underlying resistance to metronomic chemotherapy remain unclear. Therefore, we herein conducted a single institutional phase I/II trial to assess the efficacy and safety of metronomic chemotherapy with bleomycin plus S-1, an oral 5-FU prodrug, in the neoadjuvant setting for patients with oral squamous cell carcinoma (OSCC). The response rate of well-differentiated OSCC to metronomic chemotherapy was significantly lower. We investigated differences in molecular profiles between poorly or moderately differentiated head and neck squamous cell carcinoma (HNSCC) and well-differentiated HNSCC from patients with HNSCC TCGA data. EphA4 expression positively correlated with histological differentiation. An upstream regulator analysis correlated with EphA4 expression identified pathways associated with decreased mTORC1 signaling and T cell activation, including TCR, CD3, CD28, and CD40LG. An EphA4 blocking peptide (KYL) induced mTOR activation in well-differentiated OSCC cell lines. Plasmacytoid dendritic cell and CD8⁺ T cell numbers were higher in the microenvironment of poorly or moderately differentiated HNSCC than in that of well-differentiated HNSCC. Well-differentiated HNSCC had the characteristics of "cold tumors" (immune-excluded tumors). Moreover, KYL used with chemotherapeutic drugs synergistically increased cancer cell death. Well-differentiated OSCC is depleted of immune cells, which may be partly explained by the receptor tyrosine kinase EphA4.

Oncolytic BHV-1 Is Sufficient to Induce Immunogenic Cell Death and Synergizes with Low-Dose Chemotherapy to Dampen Immunosuppressive T Regulatory Cells

Immunogenic cell death (ICD) can switch immunologically "cold" tumors "hot", making them sensitive to immune checkpoint inhibitor (ICI) therapy. Many therapeutic platforms combine multiple modalities such as oncolytic viruses (OVs) and low-dose chemotherapy to induce ICD and improve prognostic outcomes. We previously detailed many unique properties of oncolytic bovine herpesvirus type 1 (oBHV) that suggest widespread clinical utility. Here, we show for the first time, the ability of oBHV monotherapy to induce bona fide ICD and tumor-specific activation of circulating CD8⁺ T cells in a syngeneic murine model of melanoma. The addition of low-dose mitomycin C (MMC) was necessary to fully synergize with ICI through early recruitment of CD8⁺ T cells and reduced infiltration of highly suppressive PD-1⁺ Tregs. Cytokine and gene expression analyses within treated tumors suggest that the addition of MMC to oBHV therapy shifts the immune response from predominantly anti-viral, as evidenced by a high level of interferon-stimulated genes, to one that stimulates myeloid cells, antigen presentation and adaptive processes. Collectively, these data provide mechanistic insights into how oBHV-mediated therapy modalities overcome immune suppressive tumor microenvironments to enable the efficacy of ICI therapy.

Enhanced efficacy of direct immunochemotherapy for hepatic cancer with image-guided intratumoral radiofrequency hyperthermia

BACKGROUND

It is still a challenge to prevent tumor recurrence post radiofrequency ablation (RFA) of medium-to-large hepatocellular carcinomas (HCC). Immunochemotherapy, a combination of immunotherapy with chemotherapy, has demonstrated a great potential in augmenting the treatment efficacy for some malignancies. In this study, we validated the feasibility of using radiofrequency hyperthermia (RFH)-enhanced intratumoral immunochemotherapy of LTX-315 with liposomal doxorubicin for rat orthotopic HCC.

METHODS

Different groups of luciferase-labeled rat HCC cells and rat orthotopic HCC models were treated by: (1) phosphate buffered saline; (2) RFH; (3) LTX-315; (4) RFH+LTX-315; (5) liposomal doxorubicin; (6) RFH+liposomal doxorubicin; (7) LTX-315+liposomal doxorubicin; and (8) RFH+LTX-315+liposomal doxorubicin. Cell viabilities and apoptosis of different treatment groups were compared. Changes in tumor sizes were quantified by optical and ultrasound imaging, which were confirmed by subsequent histopathology. The potential underlying biological mechanisms of the triple combination treatment (RFH+LTX-315+liposomal doxorubicin) were explored.

RESULTS

Flow cytometry and MTS assay showed the highest percentage of apoptotic cells and lowest cell viability in the triple combination treatment group compared with other seven groups (p<0.001). Tumors in this group also presented the most profound decrease in bioluminescence signal intensities and the smallest tumor volumes compared with other seven groups (p<0.001). A significant increase of CD8+ T cells, CD8+/interferon (IFN)-γ+ T cells, CD8+/tumor necrosis factor (TNF)-α+ T cells, and natural killer cells, and a significant decrease of regulatory T cells were observed in the tumors (p<0.001). Meanwhile, a significantly higher level of Th1-type cytokines in both plasma (interleukin (IL)-2, IL-12, IL-18, IFN-γ) and tumors (IL-2, IL-18, IFN-γ, TNF-α), as well as a significantly lower Th2-type cytokines of IL-4 and IL-10 in plasma and tumor were detected.

CONCLUSIONS

Intratumoral RFA-associated RFH could enhance the efficacy of immunochemotherapy of LTX-315 with liposomal doxorubicin for HCC, which may provide a new strategy to increase the curative efficacy of thermal ablation for medium-to-large HCC.

Cyclophosphamide depletes tumor infiltrating T regulatory cells and combined with anti-PD-1 therapy improves survival in murine neuroblastoma

The outcome for children with high-risk neuroblastoma is poor despite intensive multi-modal treatment protocols. Toxicity from current treatments is significant, and novel approaches are needed to improve outcome. Cyclophosphamide (CPM) is a key component of current chemotherapy regimens and is known to have immunomodulatory effects. However, this has not been investigated in the context of tumor infiltrating lymphocytes in neuroblastoma. Using murine models of neuroblastoma, the immunomodulatory effects of low-dose CPM were investigated using detailed immunophenotyping. We demonstrated that CPM resulted in a specific depletion of intratumoral T regulatory cells by apoptosis, and when combined with anti-PD-1 antibody therapy, this resulted in improved therapeutic efficacy. CPM combined with anti-PD-1 therapy was demonstrated to be an effective combinational therapy, with metronomic CPM found to be more effective than single dosing in more resistant tumor models. Overall, this pre-clinical data strongly support clinical evaluation of such combination strategies in neuroblastoma.

AMPA Receptor Encephalitis in a Patient With Metastatic Breast Cancer Receiving Palbociclib

Objective

To report a case of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor encephalitis (AMPARE) as a potential immune-mediated complication of palbociclib (a cyclin-dependent kinase 4/6 inhibitor).

Background

Medication-induced autoimmune encephalitis is an increasingly recognized entity. To date, cases have been reported with immune checkpoint inhibitors (ICIs), typically within 3 months and while cancer is responding to immunotherapy.

Results

A 55-year-old woman with metastatic breast cancer presented with new-onset neurologic symptoms. After diagnosis and treatment in 2008, she was in remission from 2010 to 2021. In April 2021, she developed metastatic recurrence. She started palbociclib in June 2021. PET scan in August 2021 showed improved metastases without new lesions. In September 2021, she developed encephalopathy, vertical nystagmus, and ataxia. Workup revealed AMPA-R antibodies. Palbociclib was stopped, and she received steroids, IVIg, and rituximab with marked improvement in her neurologic symptoms.

Discussion

AMPARE is a well-described paraneoplastic syndrome. However, it is now understood that paraneoplastic syndromes can be driven by immunomodulatory medications, namely ICIs. Although palbociclib primarily prevents tumor proliferation, emerging data suggest that it may also be immunomodulatory. Given that our patient's AMPARE developed shortly after initiation of palbociclib while her cancer was responding to therapy, we postulate that it may have been unmasked by palbociclib, similarly to what has been reported with ICIs.

Immunoenhancement Effects of the Herbal Formula Hemomine on Cyclophosphamide-Induced Immunosuppression in Mice

Hemomine is an herbal blend comprising Angelicae Gigantis Radix and other herbs known to have immunomodulatory effects. We examined the immunopotentiating effect of this herbal blend on cyclophosphamide (CPA)-induced immunosuppression. Male mice were assigned to one of six groups: the intact control and five CPA treatment groups (one control, one reference (β-glucan), and three with the application of hemomine at different concentrations; 4, 2, or 1 mL/kg; n = 10 per group). Mice were injected with CPA to induce myelosuppression and immunosuppression, after which they received one of the experimental treatments. In immunosuppressed mice, hemomine treatment alleviated the noticeable reductions in body, spleen, and submandibular lymph node weights caused by CPA; caused changes in hematological markers; induced the reduced levels of serum IFN-γ and spleen TNF-α, IL-1β, and IL-10 by CPA; improved natural killer cell activities in the spleen and peritoneal cavity; and also improved lymphoid organ atrophy in a dose-dependent manner. We demonstrate that hemomine, a mixture of six immunomodulatory herbs, is an effective immunomodulatory agent, with the potential to enhance immunity.

Cell-penetrating peptides improve pharmacokinetics and pharmacodynamics of anticancer drugs

This review concentrates on the research concerning conjugates of anticancer drugs with versatile cell-penetrating peptides (CPPs). For a better insight into the relationship between the components of the constructs, it starts with the characteristic of the peptides and considers its following aspects: mechanisms of cellular internalization, interaction with cancer-modified membranes, selectivity against tumor tissue. Also, CPPs with anticancer activity have been distinguished and summarized with their mechanisms of action. With respect to the conjugates, the preclinical studies (in vitro, in vivo) indicated that they possess several merits in comparison to the parent drugs. They concerned not only better cellular internalization but also other improvements in pharmacokinetics (e.g. access to the brain tissue) and pharmacodynamics (e.g. overcoming drug resistance). The anticancer activity of the conjugates was usually superior to that of the unconjugated drug. Certain anticancer CPPs and conjugates entered clinical trials.

Fabrication of a Silk Sericin Hydrogel System Delivering Human Lactoferrin Using Genetically Engineered Silk with Improved Bioavailability to Alleviate Chemotherapy-Induced Immunosuppression

Chemotherapy is one of the main treatments for cancer; however, it usually causes severe atrophy of immune organs and self-immunity damage to patients. Human lactoferrin (hLF) is a multiple biofunctional protein in regulating the immune response and thus holds great promise to alleviate chemotherapy-caused immunosuppression. However, a sufficient hLF resource and efficient delivery of hLF remain a challenge. Here, we provide a useful strategy to simultaneously solve these two problems. A silk sericin hydrogel system delivering recombinant hLF (SSH-rhLF) was fabricated to alleviate the chemotherapeutic drug-caused side effects by rhLF-carrying silk cocoons, which were cost-effectively produced by a transgenic silkworm strain as the resource. SSH-rhLF with a uniform porous microstructural morphology, a dominant β-sheet internal structure, adjustable concentration and sustainable release of the rhLF, and non-cytotoxicity properties was demonstrated. Interestingly, the sericin hydrogel showed effective protection of the rhLF from degradation in the stomach and small intestine, thus prolonging the bioactivity and bioavailability of rhLF. As a result, the oral administration of SSH-rhLF with a low rhLF dose showed significant therapeutic effects on enhancing the immune organs of cyclophosphamide (CTX)-treated mice by protecting the splenic follicles, promoting the expression of immunoregulatory factors, and recovering the intestinal flora family from CTX-induced imbalance, which were similar to those achieved by oral administration of a high dose of free hLF in the solution form. The results suggest that the strategy of producing rhLF silk cocoons via feeding transgenic silkworms overcomes well the shortage of rhLF resources, improves the bioavailability of oral rhLF, and alleviates the side effects of chemotherapeutic drugs on immune organs. The oral SSH-rhLF will be promising for applications in cancer chemotherapy and immunity enhancement of patients.

Synthesis, characterization, cytotoxicity studies, theoretical approach of adsorptive removal and molecular calculations of four new phosphoramide derivatives and related graphene oxide

In this study, four novel phosphoramide ligands (L1-L4) are synthesized and characterized by ³¹PNMR, ¹HNMR, MASS, and FT-IR spectroscopies. In vitro cell growth inhibition is studied by the MTT assay to evaluate the cytotoxicity of ligands against MCF-7 cell line; the result of the assay demonstrates that all ligands significantly suppress the proliferation of breast cancer cells in a concentration-dependent manner. The calculated IC₅₀ values are in the range of 3.6-10.77 µg ml^-1, of which the lowest value is attributed to L1. Then a facile approach was developed to functionalize graphene oxide (GO) surface by L1. The data which are obtained by XRD, FT-IR, and EDX analysis confirmed the deposition of phosphoramide on the surface of GO. The cell viability of GO-L1 compound at different concentrations is investigated in 24 h experiment. Excellent synergistic antitumor effects of GO and L1 lead to a decrease in IC₅₀ value up to 2.13 μg ml^-1. The Quantum calculations of compounds are used to study energies and HOMO and LUMO values, dipole moments (µ), global hardness (η), global softness (σ), and electrophilicity index (ω) using DMol³ module in Material studio2017. The docking calculations are performed to describe the mode of the binding to DNA and DNA polymerase IIα. Adsorption calculations of ligands (L1-L4) on GO sheet in the presence of water showed that L1 and L2 were located on GO via π electrons of anisole ring. While, L3 and L4 were located on GO by π - π interactions of aniline ring.

Immune checkpoint blockade in triple negative breast cancer influenced by B cells through myeloid-derived suppressor cells

Triple negative breast cancer holds a dismal clinical outcome and as such, patients routinely undergo aggressive, highly toxic treatment regimens. Clinical trials for TNBC employing immune checkpoint blockade in combination with chemotherapy show modest prognostic benefit, but the percentage of patients that respond to treatment is low, and patients often succumb to relapsed disease. Here, we show that a combination immunotherapy platform utilizing low dose chemotherapy (FEC) combined with oncolytic virotherapy (oHSV-1) increases tumor-infiltrating lymphocytes, in otherwise immune-bare tumors, allowing 60% of mice to achieve durable tumor regression when treated with immune checkpoint blockade. Whole-tumor RNA sequencing of mice treated with FEC + oHSV-1 shows an upregulation of B cell receptor signaling pathways and depletion of B cells prior to the start of treatment in mice results in complete loss of therapeutic efficacy and expansion of myeloid-derived suppressor cells. Additionally, RNA sequencing data shows that FEC + oHSV-1 suppresses genes associated with myeloid-derived suppressor cells, a key population of cells that drive immune escape and mediate therapeutic resistance. These findings highlight the importance of tumor-infiltrating B cells as drivers of antitumor immunity and their potential role in the regulation of myeloid-derived suppressor cells.

Treatment with lentiviral vectors encoding shRNA against interleukin 10 modulates the immunosuppressive activity of murine colon carcinoma-associated myeloid-derived suppressor cells

Myeloid-derived suppressor cells (MDSCs) are potent suppressors of antitumor immunity and their accumulation is often associated with poor prognosis. The aim of the present study was to determine the mechanisms of action of lentiviral vectors encoding short hairpin (sh)RNA against interleukin-10 (IL-10), with particular emphasis on their influence on the activity of tumor-derived MDSCs. Lentiviral vectors encoding shRNA against IL-10 (shIL-10 LVs) were utilized to silence the expression of IL-10 either in MDSCs that were generated ex vivo from bone marrow cells cultured in the presence of supernatant from MC38 colon carcinoma cells, or in situ in the MC38 murine colon carcinoma environment. Although monocytic MDSCs (M-MDSCs) transduced with shIL-10 LVs exhibited increased suppressor activity, transduction of polymorphonuclear MDSCs (PMN-MDSCs) appeared to reduce their ability to inhibit T lymphocyte functions. Analysis of EGFP expression in MC38 tumors revealed that intratumorally inoculated shIL-10 LVs transduced tumor-infiltrating myeloid cells with the highest efficiency and, led to a decreased IL-10 level in the tumor microenvironment. However, the effect was accompanied by increased influx of PMN-MDSCs into tumors observed both on the 6th and on the 10th day after shIL-10 LV injections. Nevertheless, it was noted that suppressor activity of myeloid cells isolated from tumors was dependent on the efficiency of tumor-derived PMN-MDSC transduction with shIL-10 LVs. The increased percentage of transduced PMN-MDSCs on the 10th day was associated with diminished immunosuppressive activity of tumor-derived myeloid cells and an elevated ratio of cytotoxic T lymphocytes to M-MDSCs. The obtained data indicated that treatment with shIL-10 LVs may result in modulation of the immunosuppressive activity of MC38 colon carcinoma-derived MDSCs.

Effect of cabazitaxel on macrophages improves CD47-targeted immunotherapy for triple-negative breast cancer

Background

Limited therapeutic options are available for triple-negative breast cancer (TNBC), emphasizing an urgent need for more effective treatment approaches. The development of strategies by targeting tumor-associated macrophages (TAMs) to stimulate their ability of Programmed Cell Removal (PrCR) provides a promising new immunotherapy for TNBC treatment.

Methods

CD47 is a critical self-protective “don’t eat me” signal on multiple human cancers against macrophage immunosurveillance. Using human and mouse TNBC preclinical models, we evaluated the efficacy of PrCR-based immunotherapy by blocking CD47. We performed high-throughput screens on FDA-approved anti-cancer small molecule compounds for agents potentiating PrCR and enhancing the efficacy of CD47-targeted therapy for TNBC treatment.

Results

We showed that CD47 was widely expressed on TNBC cells and TAMs represented the most abundant immune cell population in TNBC tumors. Blockade of CD47 enabled PrCR of TNBC cells, but the efficacy was not satisfactory. Our high-throughput screens identified cabazitaxel in enhancing PrCR-based immunotherapy. A combination of CD47 blockade and cabazitaxel treatment yielded a highly effective treatment strategy, promoting PrCR of TNBC cells and inhibiting tumor development and metastasis in preclinical models. We demonstrated that cabazitaxel potentiated PrCR by activating macrophages, independent of its cytotoxicity toward cancer cells. When treated with cabazitaxel, the molecular and phenotypic signatures of macrophages were polarized toward M1 state, and the NF-kB signaling pathway became activated.

Conclusion

The combination of CD47 blockade and macrophage activation by cabazitaxel synergizes to vastly enhance the elimination of TNBC cells. Our results show that targeting macrophages is a promising and effective strategy for TNBC treatment.

Multi-omics tumor profiling technologies to develop precision medicine in multiple myeloma

Multiple myeloma (MM), the second most common hematologic cancer, is caused by accumulation of aberrant plasma cells in the bone marrow. Its molecular causes are not fully understood and its great heterogeneity among patients complicates therapeutic decision-making. In the past decades, development of new therapies and drugs have significantly improved survival of MM patients. However, resistance to drugs and relapse remain the most common causes of mortality and are the major challenges to overcome. The advent of high throughput omics technologies capable of analyzing big amount of clinical and biological data has changed the way to diagnose and treat MM. Integration of omics data (gene mutations, gene expression, epigenetic information, and protein and metabolite levels) with clinical histories of thousands of patients allows to build scores to stratify the risk at diagnosis and predict the response to treatment, helping clinicians to make better educated decisions for each particular case. There is no doubt that the future of MM treatment relies on personalized therapies based on predictive models built from omics studies. This review summarizes the current treatments and the use of omics technologies in MM, and their importance in the implementation of personalized medicine.

Multi-omics tumor profiling technologies to develop precision medicine in multiple myeloma

Multiple myeloma (MM), the second most common hematologic cancer, is caused by accumulation of aberrant plasma cells in the bone marrow. Its molecular causes are not fully understood and its great heterogeneity among patients complicates therapeutic decision-making. In the past decades, development of new therapies and drugs have significantly improved survival of MM patients. However, resistance to drugs and relapse remain the most common causes of mortality and are the major challenges to overcome. The advent of high throughput omics technologies capable of analyzing big amount of clinical and biological data has changed the way to diagnose and treat MM. Integration of omics data (gene mutations, gene expression, epigenetic information, and protein and metabolite levels) with clinical histories of thousands of patients allows to build scores to stratify the risk at diagnosis and predict the response to treatment, helping clinicians to make better educated decisions for each particular case. There is no doubt that the future of MM treatment relies on personalized therapies based on predictive models built from omics studies. This review summarizes the current treatments and the use of omics technologies in MM, and their importance in the implementation of personalized medicine.

Arginase Therapy Combines Effectively with Immune Checkpoint Blockade or Agonist Anti-OX40 Immunotherapy to Control Tumor Growth

Metabolic dysregulation is a hallmark of cancer. Many tumors exhibit auxotrophy for various amino acids, such as arginine, because they are unable to meet the demand for these amino acids through endogenous production. This vulnerability can be exploited by employing therapeutic strategies that deplete systemic arginine in order to limit the growth and survival of arginine auxotrophic tumors. Pegzilarginase, a human arginase-1 enzyme engineered to have superior stability and enzymatic activity relative to the native human arginase-1 enzyme, depletes systemic arginine by converting it to ornithine and urea. Therapeutic administration of pegzilarginase in the setting of arginine auxotrophic tumors exerts direct antitumor activity by starving the tumor of exogenous arginine. We hypothesized that in addition to this direct effect, pegzilarginase treatment indirectly augments antitumor immunity through increased antigen presentation, thus making pegzilarginase a prime candidate for combination therapy with immuno-oncology (I-O) agents. Tumor-bearing mice (CT26, MC38, and MCA-205) receiving pegzilarginase in combination with anti-PD-L1 or agonist anti-OX40 experienced significantly increased survival relative to animals receiving I-O monotherapy. Combination pegzilarginase/immunotherapy induced robust antitumor immunity characterized by increased intratumoral effector CD8⁺ T cells and M1 polarization of tumor-associated macrophages. Our data suggest potential mechanisms of synergy between pegzilarginase and I-O agents that include increased intratumoral MHC expression on both antigen-presenting cells and tumor cells, and increased presence of M1-like antitumor macrophages. These data support the clinical evaluation of I-O agents in conjunction with pegzilarginase for the treatment of patients with cancer.

Machine and deep learning approaches for cancer drug repurposing

Knowledge of the underpinnings of cancer initiation, progression and metastasis has increased exponentially in recent years. Advanced "omics" coupled with machine learning and artificial intelligence (deep learning) methods have helped elucidate targets and pathways critical to those processes that may be amenable to pharmacologic modulation. However, the current anti-cancer therapeutic armamentarium continues to lag behind. As the cost of developing a new drug remains prohibitively expensive, repurposing of existing approved and investigational drugs is sought after given known safety profiles and reduction in the cost barrier. Notably, successes in oncologic drug repurposing have been infrequent. Computational in-silico strategies have been developed to aid in modeling biological processes to find new disease-relevant targets and discovering novel drug-target and drug-phenotype associations. Machine and deep learning methods have especially enabled leaps in those successes. This review will discuss these methods as they pertain to cancer biology as well as immunomodulation for drug repurposing opportunities in oncologic diseases.

Enhanced immunotherapeutic profile of oncolytic virus-based cancer vaccination using cyclophosphamide preconditioning

Despite a sizeable body of research, the efficacy of therapeutic cancer vaccines remains limited when applied as sole agents. By using a prime:boost approach involving two viral cancer vaccines, we were able to generate large tumor-specific CD8⁺ T-cell responses in a murine model of disseminated pulmonary melanoma. Significant increases in the number and quality of circulating effector T-cells were documented when low-dose cyclophosphamide (CTX) was administered pre-vaccination to tumor-bearing but not tumor-free hosts. Interestingly, tumor-bearing mice receiving CTX and co-primed with a melanoma differentiation antigen together with an irrelevant control antigen exhibited significantly enhanced immunity against the tumor, but not the control antigen, in secondary lymphoid organs. This result highlighted an increased cancer-specific reactivity of vaccine-induced T-cell responses following CTX preconditioning. Additionally, an acute reduction of the frequency of peripheral regulatory T-cells (Tregs) was noticeable, particularly in the proliferating, presumably tumour-reactive, subset. Enhanced infiltration of lungs with multifunctional T-cells resulted in overt reduction in metastatic burden in mice pretreated with CTX. Despite doubling the median survival in comparison to untreated controls, most vaccinated mice ultimately succumbed to cancer progression. However, preconditioning of the virus-based vaccination with CTX resulted in a remarkable improvement of the therapeutic activity leading to complete remission in the majority of the animals. Collectively, these data reveal how CTX can potentiate specific cellular immunity in an antigen-restricted manner that is only observed in vaccinated tumor-bearing hosts while depleting replicating Tregs. A single low dose of CTX enhances antitumor immunity and the efficacy of this potent prime:boost platform by modulating the kinetics of the vaccine-specific responses. Clinical assessment of CTX combined with next-generation cancer vaccines is indicated.

Repurposing Food and Drug Administration-Approved Drugs to Promote Antitumor Immunity

There has been a major resurgence of interest in immune-based approaches to treat cancer, based largely on the success of checkpoint inhibitors (anti-cytotoxic T-lymphocyte-associated antigen 4, anti-programmed cell death 1, and anti-programmed cell death ligand 1 antibodies) in several malignancies. However, not all tumors respond to checkpoint therapy, and there is clearly a need for additional approaches for enhancing tumor immunity. We summarize the critical elements necessary for mounting an efficacious T-cell response to a tumor. We cite drugs approved by the Food and Drug Administration for no-cancer indications that could be repurposed and used as part of an antitumor immune cocktail. We also list cancer drugs not initially intended to impact tumor immunity (soft repurposing) but that have been found to modulate the immune system. We highlight those drugs that might be used in combination with checkpoint inhibitors to increase response rates and survival of cancer patients. Our focus will be on drugs for which there are limited but existing human data. We cite supporting mechanistic mouse data as well. Repurposing drugs to modulate antitumor immunity is an opportunity to rapidly bring new, effective, and affordable treatments to cancer patients.

Intratumoral Immunotherapy for Early-stage Solid Tumors

The unprecedented benefits of immunotherapy in advanced malignancies have resulted in increased interests in exploiting immune stimulatory agents in earlier-stage solid tumors in the neoadjuvant setting. However, systemic delivery of immunotherapies may cause severe immune-related side-effects and hamper the development of combination treatments. Intratumoral delivery of neoadjuvant immunotherapy provides a promising strategy in harnessing the power of immunotherapy while minimizing off-target toxicities. The direct injection of immune stimulating agents into the tumor primes the local tumor-specific immunity to generate a systemic, durable clinical response. Intratumoral immunotherapy is a highly active area of investigation resulting in a plethora of agents, for example, immune receptor agonists, non-oncolytic and oncolytic viral therapies, being tested in preclinical and clinical settings. Currently, more than 20 neoadjuvant clinical trials exploring distinct intratumoral immune stimulatory agents and their combinations are ongoing. Practical considerations, including appropriate timing and optimal local delivery of immune stimulatory agents play an important role in safety and efficacy of this approach. Here, we discuss promising approaches in drug delivery technologies and opportunity for combining intratumoral immunotherapy with other cancer treatments and summarize the recent preclinical and clinical evidences that highlighted its promise as a part of routine oncologic care.

CyBorD-DARA is potent initial induction for MM and enhances ADCP: initial results of the 16-BCNI-001/CTRIAL-IE 16-02 study

Daratumumab (DARA) has shown impressive activity in combination with other agents for the treatment of multiple myeloma (MM). We conducted a phase 1b study to assess the safety and preliminary efficacy, as well as potential mechanisms of action, of DARA (16 mg/kg) in combination with a weekly schedule of subcutaneous bortezomib (1.3-1.5 mg/m²), cyclophosphamide (150-300 mg/m²), and dexamethasone (40 mg) (CyBorD DARA) as initial induction before autologous stem cell transplantation (ASCT). Eligible patients were ≤70 years of age with untreated MM requiring treatment and who lacked significant comorbidities. A total of 18 patients were enrolled. Their median age was 56 years (range, 32-66 years), and all patients had Eastern Cooperative Oncology Group performance status ≤1. The International Staging System stages were I, II, and III in 78%, 17%, and 6% of patients, respectively; 28% of patients had high-risk genetic features. There was no dose-limiting toxicity, and the incidence of grade 3 or 4 infection or neutropenia was <10%. On an intention-to-treat basis, 94% achieved ≥very good partial response with ≥complete response in 44% of patients. Among 14 of 15 patients who underwent ASCT and were evaluable for response, all 14 achieved at least very good partial response, with 8 (57%) of 14 achieving complete response. After ASCT, 10 (83%) of 12 patients in whom minimal residual disease analysis was possible were negative at a sensitivity of 10^-5 (56% on intention-to-treat/whole study population) according to next-generation sequencing. Flow cytometry analysis of patient samples indicated CyBorD DARA induced activation of macrophage-mediated antibody-dependent cellular phagocytosis. This trial was registered at www.clinicaltrials.gov as #NCT02955810.

Beyond DNA Damage: Exploring the Immunomodulatory Effects of Cyclophosphamide in Multiple Myeloma

The alkylating agent cyclophosphamide has been used in the treatment of multiple myeloma for over 60 years. At low doses, cyclophosphamide also has significant immunomodulatory activity, which can be used to modify the immunosuppressive tumor microenvironment in order to augment responses to existing therapies. Immune-mediated therapies are becoming more widespread in modern approaches to myeloma treatment. In this review, we discuss the effects cyclophosphamide has on the immune system, and how it can be used synergistically with other treatment modalities including the immunomodulatory agents, monoclonal antibodies and cellular therapies.

IMMUNEPOTENT CRP plus doxorubicin/cyclophosphamide chemotherapy remodel the tumor microenvironment in an air pouch triple-negative breast cancer murine model

In 1889, Steven Paget postulated the theory that cancer cells require a permissive environment to grow. This permissive environment is known as the tumor microenvironment (TME) and nowadays it is evident that the TME is involved in the progression and response to therapy of solid cancer tumors. Triple-negative breast cancer is one of the most lethal types of cancer for women worldwide and chemotherapy remains the standard treatment for these patients. IMMUNEPOTENT CRP is a bovine dialyzable leukocyte extract with immunomodulatory and antitumor properties. The combination of chemotherapy and IMMUNEPOTENT CRP improves clinical parameters of breast cancer patients. In the current study, we aimed to evaluate the antitumor effect of doxorubicin/cyclophosphamide chemotherapy plus IMMUNEPOTENT CRP and its impact over the tumor microenvironment in a triple-negative breast cancer murine model. We evaluated CD8⁺, CD4⁺, T regulatory cells, memory T cells, myeloid-derived suppressor cells, CD71⁺, innate effector cells and molecules such as α-SMA, VEGF, CTLA-4, PD-L1, Gal-3, IDO, IL-2, IFN-γ, IL-12, IL-6, MCP-1, and IL-10 as part of the components of the TME. Doxorubicin/cyclophosphamide + IMMUNEPOTENT CRP decreased tumor volume, prolonged survival, increased infiltrating and systemic CD8⁺ T cells and decreased tumor suppressor molecules (such as PD-L1, Gal-3, and IL-10 among others). In conclusion, we suggest that IMMUNEPOTENT CRP act as a modifier of the TME and the immune response, potentiating or prolonging anti-tumor effects of doxorubicin/cyclophosphamide in a triple-negative breast cancer murine model.

Directing Traffic: How to Effectively Drive T Cells into Tumors

Although immune checkpoint inhibitors (ICI) have demonstrated clinical activity in multiple tumor types, the majority of patients do not respond to ICI monotherapy. Mounting evidence suggests that ICI-mediated clinical responses rely upon tumor infiltration by T cells that are able to recognize and kill cancer cells. Here, we review therapeutic modalities that have been shown to promote T-cell infiltration into human tumors in studies to date, and discuss emerging data guiding how these modalities can be sequenced in order to optimize T-cell effector function and memory T-cell generation, while minimizing overactivation and potential toxicity. SIGNIFICANCE: The lack of preexisting T-cell inflammation in tumors is a major barrier to effective cancer immunity. A deep understanding of the mechanisms that prevent T cells from trafficking into the tumor in a given individual will be critical for tailoring immunotherapy combinations that can overcome resistance to ICI in patients with cancer.

Gastrin vaccine improves response to immune checkpoint antibody in murine pancreatic cancer by altering the tumor microenvironment

Pancreatic cancer has been termed a 'recalcitrant cancer' due to its relative resistance to chemotherapy and immunotherapy. This resistance is thought to be due in part to the dense fibrotic tumor microenvironment and lack of tumor infiltrating CD8 + T cells. The gastrointestinal peptide, gastrin, has been shown to stimulate growth of pancreatic cancer by both a paracrine and autocrine mechanism. Interruption of gastrin at the CCK receptor may reduce tumor-associated fibrosis and alter tumor immune cells. Polyclonal Ab Stimulator (PAS) is a vaccine that targets gastrin and has been shown to prolong survival of patients with pancreatic cancer. Here, we report that PAS vaccination monotherapy elicits both a humoral and cellular immune response when used in immune competent mice-bearing pancreatic tumors and that PAS monotherapy produced a marked T-cell activation and influx of CD8 + lymphocytes into pancreatic tumors. Isolated peripheral lymphocytes elicited cytokine release upon re-stimulation with gastrin in vitro demonstrating specificity of immune activation for the target peptide. Combination therapy with PAS and PD-1 Ab activated CD4 -/CD8 - TEMRA cells important in T-cell-mediated tumor death and memory. Tumors of mice treated with PAS (250 μg) or PAS (100 and 250 μg) in combination with a PD-1 Ab were significantly smaller compared to tumors from PBS or PD-1 Ab-treated mice. When PAS was given in combination with PD-1 Ab, tumors had less fibrosis, fewer inhibitory Treg lymphocytes, and fewer tumor-associated macrophages. These findings reveal a novel approach to improve treatment strategies for pancreatic cancer.

Drug repurposing for breast cancer therapy: Old weapon for new battle

Despite tremendous resources being invested in prevention and treatment, breast cancer remains a leading cause of cancer deaths in women globally. The available treatment modalities are very costly and produces severe side effects. Drug repurposing that relate to new uses for old drugs has emerged as a novel approach for drug development. Repositioning of old, clinically approved, off patent non-cancer drugs with known targets, into newer indication is like using old weapons for new battle. The advances in genomics, proteomics and information computational biology has facilitated the process of drug repurposing. Repositioning approach not only fastens the process of drug development but also offers more effective, cheaper, safer drugs with lesser/known side effects. During the last decade, drugs such as alkylating agents, anthracyclins, antimetabolite, CDK4/6 inhibitor, aromatase inhibitor, mTOR inhibitor and mitotic inhibitors has been repositioned for breast cancer treatment. The repositioned drugs have been successfully used for the treatment of most aggressive triple negative breast cancer. The literature review suggest that serendipity plays a major role in the drug development. This article describes the comprehensive overview of the current scenario of drug repurposing for the breast cancer treatment. The strategies as well as several examples of repurposed drugs are provided. The challenges associated with drug repurposing are discussed.

Expression of costimulatory and inhibitory receptors in FoxP3+ regulatory T cells within the tumor microenvironment: Implications for combination immunotherapy approaches

The unprecedented success of immune checkpoint inhibitors has given rise to a rapidly growing number of immuno-oncology agents undergoing preclinical and clinical development and an exponential increase in possible combinations. Defining a clear rationale for combinations by identifying synergies between immunomodulatory pathways has therefore become a high priority. Immunosuppressive regulatory T cells (Tregs) within the tumor microenvironment (TME) represent a major roadblock to endogenous and therapeutic tumor immunity. However, Tregs are also essential for the maintenance of immunological self-tolerance, and share many molecular pathways with conventional T cells including cytotoxic T cells, the primary mediators of tumor immunity. Hence the inability to specifically target and neutralize Tregs within the TME of cancer patients without globally compromising self-tolerance poses a significant challenge. Here we review recent advances in the characterization of tumor-infiltrating Tregs with a focus on costimulatory and inhibitory receptors. We discuss receptor expression patterns, their functional role in Treg biology and mechanistic insights gained from targeting these receptors in preclinical models to evaluate their potential as clinical targets. We further outline a framework of parameters that could be used to refine the assessment of Tregs in cancer patients and increase their value as predictive biomarkers. Finally, we propose modalities to integrate our increasing knowledge on Treg phenotype and function for the rational design of checkpoint inhibitor-based combination therapies. Such combinations have great potential for synergy, as they could concomitantly enhance cytotoxic T cells and inhibit Tregs within the TME, thereby increasing the efficacy of current cancer immunotherapies.

Combining the oncolytic peptide LTX-315 with doxorubicin demonstrates therapeutic potential in a triple-negative breast cancer model

Background

Immunochemotherapy, the combined use of immunotherapy and chemotherapy, has demonstrated great promise in several cancers. LTX-315 is an oncolytic peptide with potent immunomodulatory properties designed for the local treatment of solid tumors. By inducing rapid immunogenic cell death through the release of danger-associated molecular pattern molecules (DAMPs), LTX-315 is capable of reshaping the tumor microenvironment, turning “cold” tumors “hot” through a significant increase in tumor-infiltrating lymphocytes.

Methods

We investigated the potential of LTX-315 to be used in combination with standard-of-care chemotherapy (doxorubicin, brand name CAELYX®) against triple-negative breast cancer in an orthotopic 4 T1 mammary fat pad model. Tumor growth curves were compared using one-way ANOVA analysis of variance and Tukey’s multiple comparisons test, and animal survival curves were compared using the log-rank (Mantel-Cox) test. We considered p values ≤0.05 to indicate statistical significance.

Results

We found that LTX-315 displayed a strong additive antitumoral effect when used in combination with CAELYX®, and induced immune-mediated changes in the tumor microenvironment, followed by complete regression in the majority of animals treated. Furthermore, imaging techniques and histological examination showed that the combination induced strong local necrosis, followed by an increase in the infiltration of CD4+ and CD8+ immune cells into the tumor parenchymal tissue.

Conclusions

Our data demonstrate that LTX-315 is a promising combination partner with CAELYX® for the treatment of triple-negative breast cancer.

Tumor microenvironment modulation enhances immunologic benefit of chemoradiotherapy

BACKGROUND

Chemoradiotherapy (CRT) remains one of the most common cancer treatment modalities, and recent data suggest that CRT is maximally effective when there is generation of an anti-tumoral immune response. However, CRT has also been shown to promote immunosuppressive mechanisms which must be blocked or reversed to maximize its immune stimulating effects.

METHODS

Therefore, using a preclinical model of human papillomavirus (HPV)-associated head and neck squamous cell carcinoma (HNSCC), we developed a clinically relevant therapy combining CRT and two existing immunomodulatory drugs: cyclophosphamide (CTX) and the small molecule inducible nitric oxide synthase (iNOS) inhibitor L-n6-(1-iminoethyl)-lysine (L-NIL). In this model, we treated the syngeneic HPV-HNSCC mEER tumor-bearing mice with fractionated (10 fractions of 3 Gy) tumor-directed radiation and weekly cisplatin administration. We compared the immune responses induced by CRT and those induced by combinatory treatment (CRT + CTX/L-NIL) with flow cytometry, quantitative multiplex immunofluorescence and by profiling immune-related gene expression changes.

RESULTS

We show that combination treatment favorably remodels the tumor myeloid immune microenvironment including an increase in anti-tumor immune cell types (inflammatory monocytes and M1-like macrophages) and a decrease in immunosuppressive granulocytic myeloid-derived suppressor cells (MDSCs). Intratumoral T cell infiltration and tumor antigen specificity of T cells were also improved, including a 31.8-fold increase in the CD8+ T cell/ regulatory T cell ratio and a significant increase in tumor antigen-specific CD8+ T cells compared to CRT alone. CTX/LNIL immunomodulation was also shown to significantly improve CRT efficacy, leading to rejection of 21% established tumors in a CD8-dependent manner.

CONCLUSIONS

Overall, these data show that modulation of the tumor immune microenvironment with CTX/L-NIL enhances susceptibility of treatment-refractory tumors to CRT. The combination of tumor immune microenvironment modulation with CRT constitutes a translationally relevant approach to enhance CRT efficacy through enhanced immune activation.

Combination Immunotherapy: Taking Cancer Vaccines to the Next Level

With the advent of checkpoint blockade therapies, immunotherapy is now a critical modality for the treatment of some cancers. While some patients respond well to checkpoint blockade, many do not, necessitating the need for other forms of therapy. Vaccination against malignancy has been a long sought goal of science. For cancers holding a microbial etiology, vaccination has been highly effective in reducing the incidence of disease. However, vaccination against established malignancy has been largely disappointing. In this review, we discuss efforts to develop diverse vaccine modalities in the treatment of cancer with a particular focus on melanoma. Recent work has suggested that vaccines targeting patient-specific tumor mutations may be more relevant than those targeting unmutated proteins. Nonetheless, tumor cells utilize many strategies to evade host immunity. It is likely that the full potential of cancer vaccination will only be realized when vaccines are combined with other therapies targeting tumor immunoevasive mechanisms. By modulating inhibitory molecules, regulatory immune cells, and the metabolic resources and demands of T cells, scientists and clinicians can ensure vaccine-stimulated T cells are fully functional within the immunosuppressive tumor microevironment.

Cholecystokinin receptor antagonist alters pancreatic cancer microenvironment and increases efficacy of immune checkpoint antibody therapy in mice

Advanced pancreatic ductal adenocarcinoma (PDAC) has typically been resistant to chemotherapy and immunotherapy; therefore, novel strategies are needed to enhance therapeutic response. Cholecystokinin (CCK) has been shown to stimulate growth of pancreatic cancer. CCK receptors (CCKRs) are present on pancreatic cancer cells, fibroblasts, and lymphocytes. We hypothesized that CCKR blockade would improve response to immune checkpoint antibodies by promoting influx of tumor-infiltrating lymphocytes (TILs) and reducing fibrosis. We examined the effects of CCKR antagonists or immune checkpoint blockade antibodies alone or in combination in murine models of PDAC. Monotherapy with CCKR blockade significantly decreased tumor size and metastases in SCID mice with orthotopic PDAC, and in C57BL/6 mice, it reduced fibrosis and induced the influx of TILs. Immune-competent mice bearing syngeneic pancreatic cancer (Panc02 and mT3-2D) that were treated with the combination of CCK receptor antagonists and immune checkpoint blockade antibodies survived significantly longer with smaller tumors. Tumor immunohistochemical staining and flow cytometry demonstrated that the tumors of mice treated with the combination regimen had a significant reduction in Foxp3+ T-regulatory cells and an increase in CD4+ and CD8+ lymphocytes. Masson's trichrome stain analysis revealed 50% less fibrosis in the tumors of mice treated with CCKR antagonist compared to controls and compared to checkpoint antibody therapy. CCKR antagonists given with immune checkpoint antibody therapy represent a novel approach for improving survival of PDAC. The mechanism by which this combination therapy improves the survival of PDAC may be related to the decreased fibrosis and immune cells of the tumor microenvironment.

Future perspectives in melanoma research "Melanoma Bridge", Napoli, November 30th-3rd December 2016

Major advances have been made in the treatment of cancer with targeted therapy and immunotherapy; several FDA-approved agents with associated improvement of 1-year survival rates became available for stage IV melanoma patients. Before 2010, the 1-year survival were quite low, at 30%; in 2011, the rise to nearly 50% in the setting of treatment with Ipilimumab, and rise to 70% with BRAF inhibitor monotherapy in 2013 was observed. Even more impressive are 1-year survival rates considering combination strategies with both targeted therapy and immunotherapy, now exceeding 80%. Can we improve response rates even further, and bring these therapies to more patients? In fact, despite these advances, responses are heterogeneous and are not always durable. There is a critical need to better understand who will benefit from therapy, as well as proper timing, sequence and combination of different therapeutic agents. How can we better understand responses to therapy and optimize treatment regimens? The key to better understanding therapy and to optimizing responses is with insights gained from responses to targeted therapy and immunotherapy through translational research in human samples. Combination therapies including chemotherapy, radiotherapy, targeted therapy, electrochemotherapy with immunotherapy agents such as Immune Checkpoint Blockers are under investigation but there is much room for improvement. Adoptive T cell therapy including tumor infiltrating lymphocytes and chimeric antigen receptor modified T cells therapy is also efficacious in metastatic melanoma and outcome enhancement seem likely by improved homing capacity of chemokine receptor transduced T cells. Tumor infiltrating lymphocytes therapy is also efficacious in metastatic melanoma and outcome enhancement seem likely by improved homing capacity of chemokine receptor transduced T cells. Understanding the mechanisms behind the development of acquired resistance and tests for biomarkers for treatment decisions are also under study and will offer new opportunities for more efficient combination therapies. Knowledge of immunologic features of the tumor microenvironment associated with response and resistance will improve the identification of patients who will derive the most benefit from monotherapy and might reveal additional immunologic determinants that could be targeted in combination with checkpoint blockade. The future of advanced melanoma needs to involve education and trials, biobanks with a focus on primary tumors, bioinformatics and empowerment of patients and clinicians.

Cyclophosphamide treatment regulates the balance of functional/exhausted tumor-specific CD8+ T cells

An important question is how chemotherapy may (re-)activate tumor-specific immunity. In this study, we provide a phenotypic, functional and genomic analysis of tumor-specific CD8⁺ T cells in tumor (P815)-bearing mice, treated or not with cyclophosphamide. Our data show that chemotherapy favors the development of effector-type lymphocytes in tumor bed, characterized by higher KLRG-1 expression, lower PD-1 expression and increased cytotoxicity. This suggests re-engagement of T lymphocytes into the effector program. IFN-I appears involved in this remodeling. Our findings provide some insight into how cyclophosphamide regulates the amplitude and quality of tumor-specific immune responses.

A randomized phase II trial of personalized peptide vaccine with low dose cyclophosphamide in biliary tract cancer

Since the prognosis of advanced biliary tract cancer (aBTC) still remains very poor, new therapeutic approaches, including immunotherapies, need to be developed. In the current study, we conducted an open‐label randomized phase II study to test whether low dose cyclophosphamide (CPA) could improve antigen‐specific immune responses and clinical efficacy of personalized peptide vaccination (PPV) in 49 previously treated aBTC patients. Patients with aBTC refractory to at least one regimen of chemotherapies were randomly assigned to receive PPV with low dose CPA (100 mg/day for 7 days before vaccination) (PPV/CPA, n = 24) or PPV alone (n = 25). A maximum of four HLA‐matched peptides were selected based on the pre‐existing peptide‐specific IgG responses, followed by subcutaneous administration. T cell responses to the vaccinated peptides in the PPV/CPA arm tended to be greater than those in the PPV alone arm. The PPV/CPA arm showed significantly better progression‐free survival (median time: 6.1 vs 2.9 months; hazard ratio (HR): 0.427; P = 0.008) and overall survival (median time: 12.1 vs 5.9 months; HR: 0.376; P = 0.004), compared to the PPV alone arm. The PPV alone arm, but not the PPV/CPA arm, showed significant increase in plasma IL‐6 after vaccinations, which might be associated with inhibition of antigen‐specific T cell responses. These results suggested that combined treatment with low dose CPA could provide clinical benefits in aBTC patients under PPV, possibly through prevention of IL‐6‐mediated immune suppression. Further clinical studies would be recommended to clarify the clinical efficacy of PPV/CPA in aBTC patients.

[What is the place of the combinations for immunotherapy with chemotherapy or with other immune checkpoint inhibitors?]

Immune checkpoint blockade by the use of anti-PD(L)1 or anti-CTLA4 antibodies can induce long lasting disease response and maybe cure in a lot of advanced cancer patients. This ongoing immunotherapy revolution has given new hope to cancer patients and oncologists. However, still the majority of cancer patients do not respond to immune checkpoint blockade and novel therapeutical possibilities are being tested in several clinical trials. One of the possibilities to enhance responses to immune checkpoint blockade is the combination with chemotherapy or with other immune checkpoint blockade molecules. In this review, we explore the preclinical rational for this synergism and the potential consequences for immunotherapy in oncology.

Opportunistic autoimmunity secondary to cancer immunotherapy (OASI): An emerging challenge

With "checkpoint inhibitors" targeting PD1/PD-1-ligands or CTLA-4/CD28 pathways, immunotherapy has profoundly modified therapeutic strategies in oncology. First approved in refractory metastatic neoplasms (melanoma and lung adenocarcinoma), it is now being tested broadly in other cancers and/or as adjuvant treatment. For a significant proportion of patients, immunotherapy is responsible for "immunological" events, identified as Immune-Related Adverse Events (irAEs). Owing to the increasing number of prescriptions, identification and management of specific immunological side effects is crucial and requires close collaboration between oncologists and internists and/or other organ specialists. Within irAEs, we propose to individualize the induced autoimmunity by the term "Opportunistic Autoimmunity Secondary to Cancer Immunotherapy" (OASI). The aims of this article are (1) to present the different available checkpoint inhibitors and the OASIs reported with these treatments and (2) to propose practical recommendations for diagnosis, pre-therapeutic assessment and management of OASIs. The need for predictive biomarkers of OASIs occurrence will also be discussed.

Chemotherapy and immunotherapy: A close interplay to fight cancer?

In theory, the immunotherapy of cancer should induce the selective destruction of cancer cells and a long-term specific protection, based on the specificity and memory of immunity. This contrasts with the collateral damages of conventional therapies and their toxic effects on host tissues. However, recent data suggest that chemotherapy may potentiate ongoing immune responses, through homeostatic mechanisms. Massive tumor death, empty "immune" niches and selected cytokines may act as a danger signal, alerting the immune system and amplifying pre-existing antitumor reactivity.