New avenues for the treatment of immunotherapy-resistant pancreatic cancer

Pancreatic cancer(PC)is characterized by its extremely aggressive nature and ranks 14th in the number of new cancer cases worldwide.However,due to its complexity,it ranks 7th in the list of the most lethal cancers worldwide.The pathogenesis of PC involves several complex processes,including familial genetic factors associated with risk factors such as obesity,diabetes mellitus,chronic pancreatitis,and smoking.Mutations in genes such as KRAS,TP53,and SMAD4 are linked to the appearance of malignant cells that generate pancreatic lesions and,consequently,cancer.In this context,some therapies are used for PC,one of which is immunotherapy,which is extremely promising in various other types of cancer but has shown little response in the treatment of PC due to various resistance mechanisms that contribute to a drop in immunotherapy efficiency.It is therefore clear that the tumor microenvironment(TME)has a huge impact on the resistance process,since cellular and non-cellular elements create an immunosuppressive environment,characterized by a dense desmoplastic stroma with cancerassociated fibroblasts,pancreatic stellate cells,extracellular matrix,and immunosuppressive cells.Linked to this are genetic mutations in TP53 and immunosuppressive factors that act on T cells,resulting in a shortage of CD8+T cells and limited expression of activation markers such as interferon-gamma.In this way,finding new strategies that make it possible to manipulate resistance mechanisms is necessary.Thus,techniques such as the use of TME modulators that block receptors and stromal molecules that generate resistance,the use of genetic manipulation in specific regions,such as microRNAs,the modulation of extrinsic and intrinsic factors associated with T cells,and,above all,therapeutic models that combine these modulation techniques constitute the promising future of PC therapy.Thus,this study aims to elucidate the main mechanisms of resistance to immunotherapy in PC and new ways of manipulating this process,resulting in a more efficient therapy for cancer patients and,consequently,a reduction in the lethality of this aggressive cancer.

Blockade of neutrophil recruitment to tumor sites based on sialic acid-modified nanoplatforms enhances the efficacy of checkpoint blockade immunotherapy

Checkpoint inhibitors are designed to rejuvenate depleted or suppressed T cells in the tumor microenvironment,relying on the immune system to control and kill tumors.However,accumulating evidence indicates that tumor-infiltrating neutrophils impede the proliferation and activation of T cells and determine the resistance to checkpoint blockade and chemotherapy.In this study,sialic acid ligand-modified colchicine derivative phospholipid complexes specifically targeted tumor-associated neutrophils in the peripheral blood,blocked neutrophil accumulation in tumors,and attenuated the inhibitory effect of infiltrating neutrophils on T cells.Neutrophil blocking therapy enhanced the immunotherapy effect of the PD-L1 antibody in S180 advanced tumors and 4T1 breast cancer.Our study found that PD-L1 antibody monotherapy increased the tumor infiltration of immunosuppressive neutrophils.Combination therapy with neutrophil blocking can greatly reduce tumor-infiltrating neutrophils and increase the proliferation of cytotoxic CD8^(+) T lymphocytes in the tumor.The combination therapy significantly improved the survival rate of mice with advanced S180 tumors and increased the sensitivity of immune checkpoint inhibitors to 4T1 cold tumors.

Immunotherapy of rat glioma without accumulation of CD4^+CD25^+FOXP3^+ regulatory T cells

Immunotherapy may be used for the treatment of glioblastoma multiforme; however, the induced immune response is inadequate when either T cells or dendritic cells are used alone. In this study we established a novel vaccine procedure in rats, using dendritic cells pulsed with C6 tumor cell lysates in combination with adoptive transfer of T lymphocytes from syngenic donors. On day 21 after tumor inoculation, all the rats were sacrificed, the brains were harvested for calculation of glioma volume, cytolytic T lymphocyte responses were measured by cytotoxic assay, and the frequency of regulatory T lymphocytes （CD4＋CD25~FOXP3~） in the peripheral blood was investigated by flow cytometric analysis. The survival rate of rats bearing C6 glioma was observed. Results showed that the co-immunization strategy had significant anti-tumor potential against the pre-established C6 glioma, and induced a strong cytolytic T lymphocyte response in rats. The frequency of peripheral blood CD4＊CD25＊FOXP3＊ regulatory T lymphocytes was significantly decreased following the combination therapy, and the rats survived for a longer period. Experimental findings indicate that the combined immunotherapy of glioma cell lysate-pulsed dendritic cell vaccination following adoptive transfer of T cells can effectively inhibit the growth of gliomas in rats, boost anti-tumor immunity and produce a sustained immune response while avoiding the accumulation of CD4＋CD25＋FOXP3＋ regulatory r lymphocytes.

Combined treatments in hepatocellular carcinoma:Time to put them in the guidelines?

The time for battling cancer has never been more suitable than nowadays and fortunately against hepatocellular carcinoma(HCC)we do have a far-reaching arsenal.Moreover,because liver cancer comprises a plethora of stages-from very early to advanced disease and with many treatment options–from surgery to immunotherapy trials–it leaves the clinician a wide range of options.The scope of our review is to throw light on combination treatments that seem to be beyond guidelines and to highlight these using evidence-based analysis of the most frequently used combination therapies,discussing their advantages and flaws in comparison to the current standard of care.One particular combination therapy seems to be in the forefront:Transarterial chemoembolization plus ablation for medium-size non-resectable HCC(3-5 cm),which is currently at the frontier between Barcelona Clinic Liver Cancer classification A and B.Not only does it improve the outcome in contrast to each individual therapy,but it also seems to have similar results to surgery.Also,the abundance of immune checkpoint inhibitors that have appeared lately in clinical trials are bringing promising results against HCC.Although the path of combination therapies in HCC is still filled with uncertainty and caveats,in the following years the hepatology and oncology fields could witness an HCC guideline revolution.

Immunotherapy combinations and chemotherapy sparing schemes in first line non-small cell lung cancer

In recent years,studies have explored different combinations of immunotherapy and chemotherapy.The rationale behind these is the improved survival outcomes of new immunologic therapies used in first-line-treatment of advanced non-small cell lung cancer.Moreover,for the most-studied combinations of anti-programed death-1(PD-1)/programed death ligand-1(PD-L1)with the addition of platinumbased chemotherapy,recent research is investigating whether combining different immunologic antitumoral mechanisms of action,such as anti-PD-1/PD-L1 and anti-CTLA-4,or anti-PD-L1 and anti-TIGIT,with or without chemotherapy,can improve efficacy outcomes compared with more classical combinations,or compared with standard chemotherapy alone.Here,we present the data of the main randomized studies that have evaluated these combinations,focusing on the basic rationale behind the different combinations,and the efficacy and tolerability data available to date.

Combined treatment of non-small cell lung cancer using radiotherapy and immunotherapy: challenges and updates

The efficacy of immunotherapy for advanced non-small cell lung cancer(NSCLC)remains unsatisfactory,as the majority of patients either do not experience an objective response or acquire secondary resistance.As a result,several methods to enhance the systemic efficacy of immunotherapy have been investigated,including a large area of active research by combining immunotherapy with radiation therapy(RT).Given the rapidly burgeoning concept of combining immunotherapy and RT for increasing therapeutic benefit,we review the progress in this field thus far and explore further avenues for enhancing this combination.This review commences with a discussion of the only two existing randomized trials(and a pooled analysis)showing that the addition of RT to immunotherapy improves the abscopal response rate,progression-free survival,and overall survival in metastatic NSCLC patients.We then discussed factors and biomarkers that may be associated with a proportionally greater benefit to additional RT,such as low programmed cell death protein ligand 1(PD-L1)status,tumor mutational burden(TMB),and patient’s immune function.Next,the implementation of RT to overcome immunotherapy resistance is discussed,including a mechanistic discussion and methods with which these mechanisms could be exploited.Lastly,the emerging role of low-dose RT is discussed,which may help to overcome inhibitory signals in the tumor stroma that limit T-cell infiltration.Taken together,given the current state of this rapidly expanding realm,these futuristic strategies may be reflected upon to further enhance the efficacy of immunotherapy for a wider group of patients.

The Society for Immunotherapy of Cancer clinical practice guideline on immunotherapy for hepatocellular carcinoma

The Society for Immunotherapy of Cancer(SITC)published clinical practice guideline on immunotherapy for hepatocellular carcinoma(HCC)(1).Many clinical practice guidelines for HCC have been published by academic societies worldwide(2),but the SITC guideline is the first to focus exclusively on immunotherapy.

Intracellular aggregation of peptide-reprogrammed small molecule nanoassemblies enhances cancer chemotherapy and combinatorial immunotherapy

The intracellular retention of nanotherapeutics is essential for their therapeutic activity.The immobilization of nanotherapeutics inside target cell types can regulate various cell behaviors.However,strategies for the intracellular immobilization of nanoparticles are limited.Herein,a cisplatin prodrug was synthesized and utilized as a glutathione(GSH)-activated linker to induce aggregation of the cisplatin prodrug/IR820/docetaxel nanoassembly.The nanoassembly has been reprogrammed with peptidecontaining moieties for tumor-targeting and PD-1/PD-L1 blockade.The aggregation of the nanoassemblies is dependent on GSH concentration.Evaluations in vitro and in vivo revealed that GSH-induced intracellular aggregation of the nanoassemblies enhances therapeutic activity in primary tumors by enhancing the accumulation and prolonging the retention of the chemotherapeutics in the tumor site and inducing reactive oxygen species(ROS)generation and immunogenic cell death.Moreover,the nanoassemblies reinvigorate the immunocytes,especially the systemic immunocytes,and thereby alleviate pulmonary metastasis,even though the population of immunocytes in the primary tumor site is suppressed due to the enhanced accumulation of chemotherapeutics.This strategy provides a promising option for the intracellular immobilization of nanoparticles in vitro and in vivo.

Resistance to chemoimmunotherapy in non-small-cell lung cancer

Recent clinical trials evaluating the combination of chemotherapy with immune checkpoint inhibition for the primary treatment of lung cancer showed increased progression-free and overall survival compared with chemotherapy alone.However,the combination of these two modalities is less than additive and the mechanisms of resistance to this therapeutic intervention are discussed here.So far,the conventional biomarkers for immunotherapy,namely programmed death-ligand 1 expression or tumor mutational burden are poor predictors of the efficacy of immunochemotherapy,and the optimal sequence of chemotherapy and immunotherapy has yet to be defined.

Antitumor synergism between PAK4 silencing and immunogenic phototherapy of engineered extracellular vesicles

Immunotherapy has revolutionized the landscape of cancer treatment.However,single immunotherapy only works well in a small subset of patients.Combined immunotherapy with antitumor synergism holds considerable potential to boost the therapeutic outcome.Nevertheless,the synergistic,additive or antagonistic antitumor effects of combined immunotherapies have been rarely explored.Herein,we established a novel combined cancer treatment modality by synergizing p21-activated kinase 4(PAK4)silencing with immunogenic phototherapy in engineered extracellular vesicles(EVs)that were fabricated by coating M1 macrophage-derived EVs on the surface of the nano-complex cores assembled with si RNA against PAK4 and a photoactivatable polyethyleneimine.The engineered EVs induced potent PAK4 silencing and robust immunogenic phototherapy,thus contributing to effective antitumor effects in vitro and in vivo.Moreover,the antitumor synergism of the combined treatment was quantitatively determined by the Compu Syn method.The combination index(CI)and isobologram results confirmed that there was an antitumor synergism for the combined treatment.Furthermore,the dose reduction index(DRI)showed favorable dose reduction,revealing lower toxicity and higher biocompatibility of the engineered EVs.Collectively,the study presents a synergistically potentiated cancer treatment modality by combining PAK4 silencing with immunogenic phototherapy in engineered EVs,which is promising for boosting the therapeutic outcome of cancer immunotherapy.

Novel standards and emerging therapies for systemically treatment-naïve clear cell renal cell carcinoma - a rapidly changing landscape

The last decade has brought about major advances in systemic therapy for patients with advanced clear cell renal cell carcinoma.The introduction of angiogenesis targeting agents,immune checkpoint inhibitors,and combinations thereof has resulted in a multitude of therapeutic standards for patients with newly diagnosed advanced disease.With the rapid adoption and increasing number of available options for patients,selection amongst treatment regimens has become complex.Further,a new balance is also being sought to optimize treatment outcomes and limit treatment-related toxicities.With a rising bar against which novel therapeutics are being measured,the field looks toward an evolved understanding of tumor biology to help pave new ways forward for individualized therapy.Here,we review pivotal studies that led to regulatory approvals and ongoing clinical trials conducted in patients with systemically untreated clear cell renal cell carcinoma and provide perspective on how newly emerging data can be integrated into this rapidly changing landscape.