Allogeneic vaccination with a B7.1 HLA-A gene-modified adenocarcinoma cell line in patients with advanced non-small-cell lung cancer

Integrated analysis highlights the significance role of ITGAL in lung adenocarcinoma

Integrin alpha L (ITGAL), a member of the integrin family, is associated with carcinogenesis and immune regulation. However, the biological functions of ITGAL in lung adenocarcinoma (LUAD) remain poorly understood. In this study, we utilized the TCGA dataset to analyse ITGAL mRNA expression in LUAD and examined its correlation with clinical prognosis. Three-dimensional (3D) Matrigel culture, 5-bromodeoxyuridine (BrdU) ELISA, wound-healing migration and cell adherence assays were used to demonstrate the potential role of ITGAL in LUAD progression. Additionally, we analysed single-cell sequencing data of LUAD to determine the expression and biological function of ITGAL. Our research revealed that the expression of ITGAL in LUAD samples is an independent predictor of prognosis. Patients with high expression of ITGAL had significantly better overall survival (OS), progression-free survival (PFS) and disease-specific survival (DSS) compared to the low-expression group. Meanwhile, the expression of ITGAL suppressed malignant progression in LUAD cells. Functional enrichment analyses showed that ITGAL was significantly correlated with cell immune response and immune checkpoint, consistent with the analysis of single-cell sequencing in paired samples of normal and tumour. Furthermore, we confirmed that ITGAL expression affect the tumour microenvironment (TME) through regulation of the expression of cytokines in NK cells of LUAD. In summary, ITGAL is a prognostic biomarker for LUAD patients, and it repressed malignant progression in LUAD cells. Moreover, ITGAL expression also enhanced the effect of immunotherapy and may be an important target in LUAD therapy.

Landscape of tumor and immune system cells-derived exosomes in lung cancer: mediators of antitumor immunity regulation

The immune system plays a critical role in cancer, including lung cancer, which is the leading cause of cancer-related deaths worldwide. Immunotherapy, particularly immune checkpoint blockade, has revolutionized the treatment of lung cancer, but a large subset of patients either do not respond or develop resistance. Exosomes, essential mediators of cell-to-cell communication, exert a profound influence on the tumor microenvironment and the interplay between cancer and the immune system. This review focuses on the role of tumor-derived exosomes and immune cells-derived exosomes in the crosstalk between these cell types, influencing the initiation and progression of lung cancer. Depending on their cell of origin and microenvironment, exosomes can contain immunosuppressive or immunostimulatory molecules that can either promote or inhibit tumor growth, thus playing a dual role in the disease. Furthermore, the use of exosomes in lung cancer immunotherapy is discussed. Their potential applications as cell-free vaccines and drug delivery systems make them an attractive option for lung cancer treatment. Additionally, exosomal proteins and RNAs emerge as promising biomarkers that could be employed for the prediction, diagnosis, prognosis and monitoring of the disease. In summary, this review assesses the relationship between exosomes, lung cancer, and the immune system, shedding light on their potential clinical applications and future perspectives.

Role of circulating-tumor DNA in the early-stage non-small cell lung carcinoma as a predictive biomarker

Lung cancer is one of the most common solid malignancies. Tissue biopsy is the standard method for accurately diagnosing lung and many other malignancies over decades. However, molecular profiling of tumors leads to establishing a new horizon in the field of precision medicine, which has now entered the mainstream in clinical practice. In this context, a minimally invasive complementary method has been proposed as a liquid biopsy (LB) which is a blood-based test that is gaining popularity as it provides the opportunity to test genotypes in a unique, less invasive manner. Circulating tumor cells (CTC) captivating the Circulating-tumor DNA (Ct-DNA) are often present in the blood of lung cancer patients and are the fundamental concept behind LB. There are multiple clinical uses of Ct-DNA, including its role in prognostic and therapeutic purposes. The treatment of lung cancer has drastically evolved over time. Therefore, this review article mainly focuses on the current literature on circulating tumor DNA and its clinical implications and future goals in non-small cell lung cancer.

Lung cancer immunotherapy: progress, pitfalls, and promises

Lung cancer is the primary cause of mortality in the United States and around the globe. Therapeutic options for lung cancer treatment include surgery, radiation therapy, chemotherapy, and targeted drug therapy. Medical management is often associated with the development of treatment resistance leading to relapse. Immunotherapy is profoundly altering the approach to cancer treatment owing to its tolerable safety profile, sustained therapeutic response due to immunological memory generation, and effectiveness across a broad patient population. Different tumor-specific vaccination strategies are gaining ground in the treatment of lung cancer. Recent advances in adoptive cell therapy (CAR T, TCR, TIL), the associated clinical trials on lung cancer, and associated hurdles are discussed in this review. Recent trials on lung cancer patients (without a targetable oncogenic driver alteration) reveal significant and sustained responses when treated with programmed death-1/programmed death-ligand 1 (PD-1/PD-L1) checkpoint blockade immunotherapies. Accumulating evidence indicates that a loss of effective anti-tumor immunity is associated with lung tumor evolution. Therapeutic cancer vaccines combined with immune checkpoint inhibitors (ICI) can achieve better therapeutic effects. To this end, the present article encompasses a detailed overview of the recent developments in the immunotherapeutic landscape in targeting small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). Additionally, the review also explores the implication of nanomedicine in lung cancer immunotherapy as well as the combinatorial application of traditional therapy along with immunotherapy regimens. Finally, ongoing clinical trials, significant obstacles, and the future outlook of this treatment strategy are also highlighted to boost further research in the field.

PD-L1 Biomolecules Associated with Clinical Features in Non-Melanoma Skin Cancer

Background

Increasing evidence has indicated that several B7 family members play critical roles in the progress of many cancers. However, the clinical significance of the B7 family in cutaneous squamous cell carcinoma (cSCC) is still elusive. The purpose of this study is to investigate the potential role of B7-H1 biomolecules (PD-L1) in regulating the tumorigenesis and progression of cSCC, the most common non-melanoma skin cancer.

Methods

We collected transcriptome data of cSCC patients from TCGA databases (n = 496) and subjected the transcription data to bioinformatical analysis. Differential expression of B7-H1 genes with a grade-dependent pattern was identified. We collected paraffin sections of skin squamous carcinoma and analyzed by immunohistochemical staining. We further examined the PD-L1 levels of CD14+ cells in peripheral blood of each cSCC patient and normal subjects by flow cytometry.

Results

It was found that higher expression of PD-L1 was associated with poor prognosis of cSCC patients and shorter overall survival. These observations were further verified in the clinical paraffin sections and in peripheral blood T cells.

Conclusion

Our study reveals that PD-L1 is a potential prognostic marker in clinical prognosis for cSCC patients and could be valuable for cSCC treatment.

Trypanosoma cruzi-Derived Molecules Induce Anti-Tumour Protection by Favouring Both Innate and Adaptive Immune Responses

Lung cancer remains the leading cause of cancer mortality worldwide. Thus, the development of strategies against this type of cancer is of high value. Parasite infections can correlate with lower cancer incidence in humans and their use as vaccines has been recently explored in preclinical models. In this study, we investigated whether immunisations with a Trypanosoma cruzi lysate from epimastigotes protect from lung tumour growth in mice. We also explore the role of parasite glycans in the induction of the protective immune response. A pre-clinical murine cancer model using the lung tumour cell line LL/2 was used to evaluate the anti-tumour potential, both in preventive and therapeutic settings, of a T. cruzi epimastigote-derived protein lysate. Immunisation with the parasite lysate prevents tumour growth and induces both humoral and cellular anti-tumour immune responses to LL-2 cancer cells. The induced immunity and tumour protection were associated with the activation of natural killer (NK) cells, the production of interferon-γ (IFN-γ) and tumour cell cytotoxicity. We also show that mannose residues in the T. cruzi lysate induce Toll-like receptor (TLR) signalling. The evaluated T. cruzi lysate possesses anti-tumour properties likely by activating innate and adaptive immunity in a process where carbohydrates seem to be essential.

Changing Landscape of Cancer Vaccines-Novel Proteomics Platform for New Antigen Compositions

The creation of cancer vaccines is a constant priority for research and biotechnology. Therefore, the emergence of any new technology in this field is a significant event, especially because previous technologies have not yielded results. Recently, the development of a cancer vaccine has been complemented by a new proteomics technology platform that allows the creation of antigen compositions known as antigenic essences. Antigenic essence comprises a target fraction of cellular antigens, the composition of which is precisely controlled by peptide mass spectrometry and compared to the proteomic footprint of the target cells to ensure similarity. This proteomics platform offers potential for a massive upgrade of conventional cellular cancer vaccines. Antigenic essences have the same mechanism of action, but without the disadvantages, and with notable advantages such as precise targeting of the immune response, safety, controlled composition, improved immunogenicity, addressed MHC restriction, and extended range of vaccination doses. The present paper calls attention to this novel platform, stimulates discussion of the role of antigenic essence in vaccine development, and consolidates academic science with biotech capabilities. A brief description of the platform, list of cellular cancer vaccines suitable for the upgrade, main recommendations, limitations, and legal and ethical aspects of vaccine upgrade are reported here.

Immune-related genes and gene sets for predicting the response to anti-programmed death 1 therapy in patients with primary or metastatic non-small cell lung cancer

Although antibodies targeting the immune checkpoint protein programmed death-1 (PD-1) exert therapeutic effects in patients with primary or metastatic non-small cell lung cancer (NSCLC), the majority of patients exhibit partial or complete resistance to anti-PD1 treatment. Thus, the aim of the present study was to identify reliable biomarkers for predicting the response to anti-PD-1 therapy. The present study analyzed tumor specimens isolated from 24 patients (13 with primary and 11 with metastatic NSCLC) prior to treatment with approved PD1-targeting antibodies. The expression profile of 395 immune-related genes was examined using RNA immune-oncology panel sequencing. The results demonstrated that six immune-related differently expressed genes (DEGs), including HLA-F-AS1, NCF1, RORC, DMBT1, KLRF1 and IL-18, and five DEGs, including HLA-A, HLA-DPA1, TNFSF18, IFI6 and PTK7, may be used as single biomarkers for predicting the efficacy of anti-PD-1 treatment in patients with primary and with metastatic NSCLC, respectively. In addition, two DEG sets comprising either six (HLA-F-AS1, NCF1, RORC, DMBT1, KLRF and IL-18) or two (HLA-A and TNFSF18) DEGs as potential combination biomarkers for predicting the efficacy of anti-PD-1 therapy in patients with NSCLC. Patients with a calculated expression level of the DEG sets >6.501 (primary NSCLC) or >6.741 (metastatic NSCLC) may benefit from the anti-PD-1 therapy. Overall, these findings provided a basis for the identification of additional biomarkers for predicting the response to anti-PD-1 treatment.

Dendritic cells loaded with exosomes derived from cancer stem cell-enriched spheroids as a potential immunotherapeutic option

Cancer stem cells (CSCs) are responsible for therapeutic resistance and recurrence in colorectal cancer. Despite advances in immunotherapy, the inability to specifically eradicate CSCs has led to treatment failure. Hence, identification of appropriate antigen sources is a major challenge in designing dendritic cell (DC)‐based therapeutic strategies against CSCs. Here, in an in vitro model using the HT‐29 colon cancer cell line, we explored the efficacy of DCs loaded with exosomes derived from CSC‐enriched colonospheres (CSC_enr‐EXOs) as an antigen source in activating CSC‐specific T‐cell responses. HT‐29 lysate, HT‐29‐EXOs and CSC_enr lysate were independently assessed as separate antigen sources. Having confirmed CSCs enrichment in spheroids, CSC_enr‐EXOs were purified and characterized, and their impact on DC maturation was investigated. Finally, the impact of the antigen‐pulsed DCs on the proliferation rate and also spheroid destructive capacity of autologous T cells was assessed. CSC_enr‐EXOs similar to other antigen groups had no suppressive/negative impacts on phenotypic maturation of DCs as judged by the expression level of costimulatory molecules. Notably, similar to CSC_enr lysate, CSC_enr‐EXOs significantly increased the IL‐12/IL‐10 ratio in supernatants of mature DCs. CSC_enr‐EXO‐loaded DCs effectively promoted T‐cell proliferation. Importantly, T cells stimulated with CSC_enr‐EXOs disrupted spheroids' structure. Thus, CSC_enr‐EXOs present a novel and promising antigen source that in combination with conventional tumour bulk‐derived antigens should be further explored in pre‐clinical immunotherapeutic settings for the efficacy in hampering recurrence and metastatic spread.

Pseudoprogression and hyperprogression in lung cancer: a comprehensive review of literature

PURPOSE

Immune checkpoint inhibitors are associated with clinical benefit in lung cancer. However, response patterns to immunotherapy, including pseudoprogression and hyperprogression, are difficult to diagnose, and their mechanisms remain unclear. This review aimed to describe two response patterns observed in lung cancer, namely pseudoprogression and hyperprogression, including their epidemiology, diagnostic characteristics, and plausible mechanisms.

METHODS

We performed a comprehensive literature search in the PubMed database, using keywords "pseudoprogression", "hyperprogression", and "lung cancer", among others. The literature was examined for pseudoprogression and hyperprogression characteristics and plausible mechanisms.

RESULTS

Pseudoprogression manifests in multiple forms; however, the immune system-related response criteria and biopsy data are helpful to make accurate diagnosis. Serological biomarkers, such as neutrophil-to-lymphocyte ratio (NLR) and circulating tumor DNA (ctDNA), might help distinguish pseudoprogression from true progression. The incidence of hyperprogression ranges within 5-19.2%, depending on definition. The unique response pattern of rapid progression is observed not only with immunotherapy, but also with other treatment regimens. Molecular mutations and amplifications may result in hyperprogression; however, the exact mechanism remains unclear.

CONCLUSION

Atypical response patterns, such as pseudoprogression and hyperprogression, are increasingly common in clinical practice. Immune-related response criteria can help diagnose pseudoprogression. Molecular mechanisms of hyperprogression remain unclear. Biomarkers for pseudoprogression and hyperprogression are required.

Measuring tumor mutation burden in non-small cell lung cancer: tissue versus liquid biopsy

The introduction in the clinic of immune checkpoint inhibitors (IOs) has represented an important improvement for the treatment of patients with advanced non-small cell lung cancer (NSCLC). These drugs have shown a higher activity as compared with chemotherapy in both first- and second-line of treatment, with some patients experiencing a long-lasting response. More recently, combinations of IOs have entered clinical trials in different tumor types including NSCLC. Nevertheless, IOs are active only in a subgroup of patients and biomarkers for appropriate patients' selection are urgently needed to offer the patients an effective therapy, and also to manage the costs. Tumor mutation burden (TMB) has powerfully emerged as a potential biomarker for immunotherapy and might enter the clinic in the next months, although different challenges are still unsolved. Different methods exist to evaluate TMB in tissue, ranging from whole exome sequencing (WES) to targeted sequencing of smaller sets of genes, which need to be fully standardized to ensure that patients receive an appropriate TMB test with clear clinical interpretation. In addition, as already happened for the implementation of liquid biopsy testing from NSCLC patients to identify targetable alterations, researchers are also evaluating the possibility to calculate TMB in blood, to further enlarge the number of NSCLC patients who may benefit from immunotherapy. Preliminary data highlight the difficulty to develop targeted sequencing panels for the assessment of TMB starting from the circulating cell free DNA (cfDNA). The applicability of TMB testing on liquid biopsy needs further investigation and may be clarified within the ongoing clinical trials.

Methods for improving the immunogenicity and efficacy of cancer vaccines

INTRODUCTION

Cancer vaccines represent one of the oldest immunotherapy strategies. A variety of tumor-associated antigens have been exploited to investigate their immunogenicity as well as multiple strategies for vaccine administration. These efforts have led to the development of several clinical trials in tumors with different histological origins to test the clinical efficacy of cancer vaccines. However, suboptimal clinical results have been reported mainly due to the lack of optimized strategies to induce strong and sustained systemic tumor antigen-specific immune responses.

AREAS COVERED

We provide an overview of different types of cancer vaccines that have been developed and used in the context of clinical studies. Moreover, we review different preclinical and clinical strategies pursued to enhance the immunogenicity, stability, and targeting at tumor site of cancer vaccines.

EXPERT OPINION

Additional and appropriate preclinical studies are warranted to optimize the immunogenicity and delivery of cancer vaccines. The appropriate choice of target antigens is challenging; however, the exploitation of neoantigens generated from somatic mutations of tumor cells represents a promising approach to target highly immunogenic tumor-specific antigens. Remarkably, the investigation of the combination of cancer vaccines with immunomodulating agents able to skew the tumor microenvironment from immunosuppressive to immunostimulating will dramatically improve their clinical efficacy.

Induction and characterization of anti-tumor endothelium immunity elicited by ValloVax therapeutic cancer vaccine

ValloVax is a placental endothelium derived vaccine which induces tissue-nonspecific antitumor immunity by blocking tumor angiogesis. To elucidate mechanisms of action, we showed that production of ValloVax, which involves treating placental endothelial cells with IFN-gamma, results in upregulation of HLA and costimulatory molecules. It was shown that in mixed lymphocyte reaction, ValloVax induces Type I cytokines and allo-proliferative responses. Plasma from ValloVax immunized mice was capable of killing in vitro tumor-like endothelium but not control endothelium. Using defined antigens associated with tumor endothelial cells, specific molecular entities were identified as being targeted by ValloVax induced antibodies. Binding of predominantly IgG antibodies to ValloVax cells was confirmed by flow cytometry. Further suggesting direct killing of tumor endothelial cells was expression of TUNEL positive cells, as well as, reduction in tumor oxygenation. Supporting a role for antibody mediated responses, cell depletion experiments suggested a predominant role of B cells in maintaining an intact anti-tumor endothelial response. Adoptive transfer experiments suggested that infusion of CD3+ T cells from immunized mice was sufficient to transfer tumor protection. Generation of memory T cells selective to tumor endothelial specific markers was observed. Functional confirmation of memory responses was observed in tumor rechallenge experiments. Furthermore, we observed that both PD-1 or CTLA-4 blockade augmented antitumor effects of ValloVax. These data suggest a T cell induced B cell mediated anti-tumor endothelial response and set the framework clinical trials through elucidation of mechanism of action.

Immunotherapy for Non-small-cell Lung Cancer: Current Status and Future Obstacles

Lung cancer is one of the leading causes of death worldwide. There are 2 major subtypes of lung cancer, non-small-cell lung cancer (NSCLC) and small-cell lung cancer (SCLC). Studies show that NSCLC is the more prevalent type of lung cancer that accounts for approximately 80%-85% of cases. Although, various treatment methods, such as chemotherapy, surgery, and radiation therapy have been used to treat lung cancer patients, there is an emergent need to develop more effective approaches to deal with advanced stages of tumors. Recently, immunotherapy has emerged as a new approach to combat with such tumors. The development and success of programmed cell death 1 (PD-1)/program death-ligand 1 (PD-L1) inhibitors and cytotoxic T-lymphocyte antigen 4 (CTLA-4) blockades in treating metastatic cancers opens a new pavement for the future research. The current mini review discusses the significance of immune checkpoint inhibitors in promoting the death of tumor cells. Additionally, this review also addresses the importance of tumor-specific antigens (neoantigens) in the development of cancer vaccines and major challenges associated with this therapy. Immunotherapy can be a promising approach to treat NSCLC because it stimulates host's own immune system to recognize cancer cells. Therefore, future research should focus on the development of new methodologies to identify novel checkpoint inhibitors and potential neoantigens.

Genetic Modification of the Lung Directed Toward Treatment of Human Disease

Genetic modification therapy is a promising therapeutic strategy for many diseases of the lung intractable to other treatments. Lung gene therapy has been the subject of numerous preclinical animal experiments and human clinical trials, for targets including genetic diseases such as cystic fibrosis and α1-antitrypsin deficiency, complex disorders such as asthma, allergy, and lung cancer, infections such as respiratory syncytial virus (RSV) and Pseudomonas, as well as pulmonary arterial hypertension, transplant rejection, and lung injury. A variety of viral and non-viral vectors have been employed to overcome the many physical barriers to gene transfer imposed by lung anatomy and natural defenses. Beyond the treatment of lung diseases, the lung has the potential to be used as a metabolic factory for generating proteins for delivery to the circulation for treatment of systemic diseases. Although much has been learned through a myriad of experiments about the development of genetic modification of the lung, more work is still needed to improve the delivery vehicles and to overcome challenges such as entry barriers, persistent expression, specific cell targeting, and circumventing host anti-vector responses.

A phase III study of belagenpumatucel-L, an allogeneic tumour cell vaccine, as maintenance therapy for non-small cell lung cancer

BACKGROUND

Treatment options after first-line chemotherapy are limited in non-small cell lung cancer (NSCLC). Belagenpumatucel-L is a therapeutic vaccine comprised of 4 transforming growth factor (TGF)-β2-antisense gene-modified, irradiated, allogeneic NSCLC cell lines that may be useful for maintenance after initial treatment.

METHODS

Stage III/IV NSCLC patients who did not progress after platinum-based chemotherapy were randomised 1:1 to receive maintenance belagenpumatucel-L or placebo. Patients were eligible for randomisation between one and four months from the end of induction chemotherapy. The primary endpoint was overall survival.

RESULTS

This phase III trial enrolled 270 patients in the belagenpumatucel-L arm and 262 in the control arm. Belagenpumatucel-L was well tolerated with no serious safety concerns. There was no difference in survival between the arms (median survival 20.3 versus 17.8months with belagenpumatucel-L versus placebo, respectively; hazard ratio (HR) 0.94, p=0.594). There were also no differences in progression-free survival (4.3months versus 4.0 for belagenpumatucel-L vs placebo, respectively; HR 0.99, p=0.947). A prespecified Cox regression analysis demonstrated that the time elapsed between randomisation and the end of induction chemotherapy had a significant impact on survival (p=0.002) and that prior radiation was a positive prognostic factor (median survival 28.4months with belagenpumatucel-L versus 16.0months with placebo; HR 0.61, p=0.032).

CONCLUSIONS

Although the overall trial did not meet its survival endpoint, improved survival for belagenpumatucel-L is suggested in patients who were randomised within 12weeks of completion of chemotherapy and in those who had received prior radiation. Further studies of belagenpumatucel-L in NSCLC are warranted.

Personalized approaches to active immunotherapy in cancer

Immunotherapy is emerging as a promising anti-cancer curative modality. However, in contrast to recent advances obtained employing checkpoint blockade agents and T cell therapies, clinical efficacy of therapeutic cancer vaccines is still limited. Most vaccination attempts in the clinic represent "off-the shelf" approaches since they target common "self" tumor antigens, shared among different patients. In contrast, personalized approaches of vaccination are tailor-made for each patient and in spite being laborious, hold great potential. Recent technical advancement enabled the first steps in the clinic of personalized vaccines that target patient-specific mutated neo-antigens. Such vaccines could induce enhanced tumor-specific immune response since neo-antigens are mutation-derived antigens that can be recognized by high affinity T cells, not limited by central tolerance. Alternatively, the use of personalized vaccines based on whole autologous tumor cells, overcome the need for the identification of specific tumor antigens. Whole autologous tumor cells could be administered alone, pulsed on dendritic cells as lysate, DNA, RNA or delivered to dendritic cells in-vivo through encapsulation in nanoparticle vehicles. Such vaccines may provide a source for the full repertoire of the patient-specific tumor antigens, including its private neo-antigens. Furthermore, combining next-generation personalized vaccination with other immunotherapy modalities might be the key for achieving significant therapeutic outcome.

Can dendritic cells improve whole cancer cell vaccines based on immunogenically killed cancer cells?

Immunogenic cell death (ICD) offers interesting opportunities in cancer cell (CC) vaccine manufacture, as it increases the immunogenicity of the dead CC. Furthermore, fusion of CCs with dendritic cells (DCs) is considered a superior method for generating whole CC vaccines. Therefore, in this work, we determined in naive mice whether immunogenically killed CCs per se (CC vaccine) elicit an antitumoral immune response different from the response observed when immunogenically killed CCs are associated with DCs through fusion (fusion vaccine) or through co-incubation (co-incubation vaccine). After tumor inoculation, the type of immune response in the prophylactically vaccinated mice differed between the groups. In more detail, fusion vaccines elicited a humoral anticancer response, whereas the co-incubation and CC vaccine mainly induced a cellular response. Despite these differences, all three approaches offered a prophylactic protection against tumor development in the murine mammary carcinoma model. In summary, it can be concluded that whole CC vaccines based on immunogenically killed CCs may not necessarily require association with DCs to elicit a protective anticancer immune response. If this finding can be endorsed in other cancer models, the manufacture of CC vaccines would greatly benefit from this new insight, as production of DC-based vaccines is laborious, time-consuming and expensive.

Vaccine therapy in NSCLC: a review

SUMMARY 

Approximately 200,000 people will develop lung cancer in the USA this year. Roughly 85% of those will die of their disease. Standard chemotherapeutic agents have modestly prolonged survival in this population. The discovery of activating mutations, and their inhibitors has had a more significant impact, but this is limited to the small percentage of the population that harbor the currently known mutations with approved therapeutics. Recent advances in the field of immune checkpoint inhibitors like CTLA4 or PD1 have reinvigorated the interest in immunotherapy. In this review, we will analyze the most significant findings in the field of lung cancer vaccines, and will focus on the different methods of immune activation that attempt to induce a tumor specific response.

Antibody-based immunotherapy for malignant glioma

Conventional therapy for malignant glioma (MG) fails to specifically eliminate tumor cells, resulting in toxicity that limits therapeutic efficacy. In contrast, antibody-based immunotherapy uses the immune system to eliminate tumor cells with exquisite specificity. Increased understanding of the pathobiology of MG and the profound immunosuppression present among patients with MG has revealed several biologic targets amenable to antibody-based immunotherapy. Novel antibody engineering techniques allow for the production of fully human antibodies or antibody fragments with vastly reduced antigen-binding dissociation constants, increasing safety when used clinically as therapeutics. In this report, we summarize the use of antibody-based immunotherapy for MG. Approaches currently under investigation include the use of antibodies or antibody fragments to: (1) redirect immune effector cells to target tumor mutations, (2) inhibit immunosuppressive signals and thereby stimulate an immunological response against tumor cells, and (3) provide costimulatory signals to evoke immunologic targeting of tumor cells. These approaches demonstrate highly compelling safety and efficacy for the treatment of MG, providing a viable adjunct to current standard-of-care therapy for MG.

Clinical trials targeting lung cancer with active immunotherapy: the scope of vaccines

Successful active immunotherapy is expected to be specific and nontoxic. Until now, the success of immunotherapy in cancer has been sporadic and unpredictable. This has been attributable in part to the lack of a full understanding of the mechanistic underpinnings of immune regulation. Furthermore, the lack of systematic success of immunotherapy, as argued in this review, stems from failing to effectively target tumors such as non-small cell lung cancer. In this review, the rationale and design for induction of immunity to non-small cell lung cancer and clinical trials of the most important lung cancer vaccines in development are discussed.

Allogeneic tumor cell vaccines: the promise and limitations in clinical trials

The high mortality rate associated with cancer and its resistance to conventional treatments such as radiation and chemotherapy has led to the investigation of a variety of anti-cancer immunotherapies. The development of novel immunotherapies has been bolstered by the discovery of tumor-associated antigens (TAAs), through gene sequencing and proteomics. One such immunotherapy employs established allogeneic human cancer cell lines to induce antitumor immunity in patients through TAA presentation. Allogeneic cancer immunotherapies are desirable in a clinical setting due to their ease of production and availability. This review aims to summarize clinical trials of allogeneic tumor immunotherapies in various cancer types. To date, clinical trials have shown limited success due potentially to extensive degrees of inter- and intra-tumoral heterogeneity found among cancer patients. However, these clinical results provide guidance for the rational design and creation of more effective allogeneic tumor immunotherapies for use as monotherapies or in combination with other therapies.

Cancer targeting vaccines: surrogate measures of activity

Recent FDA approval of sipuleucel-T and Ipilimumab as indicated immunologic therapy in patients with advanced prostate cancer and melanoma, respectively, has established a foothold for broader utilization of vaccine based technology in managing cancer.  Despite difficulty of cell harvest and processing with sipuleucel-T and modest toxicity to Ipilimumab, when matched up with the appropriate cancer patient these immunologic approaches have provided significant benefit and have stimulated exciting forward progress in the development of new potent and less toxic (more targeted) vaccines.  However, surrogate measures of activity to optimally define more sensitive subset populations and to determine length of treatment time in order to optimize management with other treatment options remain elusive.  Key clinically tested vaccines under development which demonstrate correlation of patient benefit to induced immune responsiveness will be discussed.  Results suggest with some vaccines correlation of patient benefit and surrogate measures of activity actually do exist.  Examples will be discussed.

Active-specific immunotherapy for non-small cell lung cancer

Non-small cell lung cancer constitutes about 85% of all newly diagnosed cases of lung cancer and continues to be the leading cause of cancer-related deaths worldwide. Standard treatment for this devastating disease, such as systemic chemotherapy, has reached a plateau in effectiveness and comes with considerable toxicities. For all stages of disease fewer than 20% of patients are alive 5 years after diagnosis; for metastatic disease the median survival is less than one year. Until now, the success of active-specific immunotherapy for all tumor types has been sporadic and unpredictable. However, the active-specific stimulation of the host's own immune system still holds great promise for achieving non-toxic and durable antitumor responses. Recently, sipuleucel-T (Provenge(®); Dendreon Corp., Seattle, WA) was the first therapeutic cancer vaccine to receive market approval, in this case for advanced prostate cancer. Other phase III clinical trials using time-dependent endpoints, e.g. in melanoma and follicular lymphoma, have recently turned out positive. More sophisticated specific vaccines have now also been developed for lung cancer, which, for long, was not considered an immune-sensitive malignancy. This may explain why advances in active-specific immunotherapy for lung cancer lag behind similar efforts in renal cell cancer, melanoma or prostate cancer. However, various vaccines are now being evaluated in controlled phase III clinical trials, raising hopes that active-specific immunotherapy may become an additional effective therapy for patients with lung cancer. This article reviews the most prominent active-specific immunotherapeutic approaches using protein/peptide, whole tumor cells, and dendritic cells as vaccines for lung cancer.

The expression, function, and clinical relevance of B7 family members in cancer

The modulation and suppression of anti-tumor immune responses is a characteristic feature of tumor cells to escape immune surveillance. Members of the B7 family are involved in this process, since the level of activation of the anti-tumor immune response depends on the balance between co-stimulatory and co-inhibitory signals. Some molecules are often overexpressed in tumors, which has been associated with the pathogenesis and progression of malignancies as well as their immunological and non-immunological functions. The B7 homologs play a key role in the maintenance of self-tolerance and the regulation of both innate and adaptive immunity in tumor-bearing hosts. Furthermore, the blockade of negative signals mediated by the interaction of co-inhibitory ligands and counter-receptors of the B7 family is currently being studied as a potential immunotherapeutic strategy for the treatment of cancer in humans.

Lung cancer: a classic example of tumor escape and progression while providing opportunities for immunological intervention

Lung cancers remain one of the most common and deadly cancers in the world today (12.5% of newly diagnosed cancers) despite current advances in chemo- and radiation therapies. Often, by the time these tumors are diagnosed, they have already metastasized. These tumors demonstrate the classic hallmarks of cancer in that they have advanced defensive strategies allowing them to escape various standard oncological treatments. Immunotherapy is making inroads towards effectively treating other fatal cancers, such as melanoma, glioblastoma multiforme, and castrate-resistant prostate cancers. This paper will cover the escape mechanisms of bronchogenic lung cancer that must be overcome before they can be successfully treated. We also review the history of immunotherapy directed towards lung cancers.

Strengths and weaknesses of immunotherapy for advanced non-small-cell lung cancer: a meta-analysis of 12 randomized controlled trials

Background

Lung cancer is one of the leading causes of cancer death worldwide. Non-small-cell lung cancer (NSCLC) accounts for approximately 85% of all lung cancers. Immunotherapy has yielded no consistent benefit to date for those patients. Assessing the objective efficacy and safety of immunotherapy for advanced NSCLC patients will help to instruct the future development of immunotherapeutic drugs.

Methodology and Principal Findings

We performed a meta-analysis of 12 randomized controlled trials including 3134 patients (1570 patients in the immunotherapy group and 1564 patients in the control group) with histologically confirmed stage IIIA, IIIB, or IV NSCLC. The analysis was executed with efficacy end points regarding overall survival (OS), progression-free survival (PFS), complete response (CR), partial response (PR), and total effective rate. Overall unstratified OS, PFS, PR, and total effective rate were significantly improved in advanced NSCLC patients in the immunotherapy group (P = 0.0007, 0.0004, 0.002, 0.003, respectively), whereas CR was not improved (P = 0.97). Subgroup analysis showed that monoclonal antibody (mAb) immunotherapy significantly improved the PFS, PR, and total effective rate and showed a trend of improving OS of advanced NSCLC patients compared with the control group, with one kind of adverse event being significantly dominant. Compared with the control group, the vaccine subgroup showed no significant difference with regard to serious adverse events, whereas cytokine immunotherapy significantly induced three kinds of serious adverse events.

Conclusions

Immunotherapy works efficiently on advanced NSCLC patients. Of several immunotherapies, mAb therapy may be a potential immunotherapy for advanced NSCLC patients, and become a standard complementary therapeutic approach in the future if the issues concerning toxicity and allergenicity of mAbs have been overcome.

Targeting costimulatory molecules to improve antitumor immunity

The full activation of T cells necessitates the concomitant activation of two signals, the engagement of T-cell receptor by peptide/major histocompatibility complex II and an additional signal delivered by costimulatory molecules. The best characterized costimulatory molecules belong to B7/CD28 and TNF/TNFR families and play crucial roles in the modulation of immune response and improvement of antitumor immunity. Unfortunately, tumors often generate an immunosuppressive microenvironment, where T-cell response is attenuated by the lack of costimulatory molecules on the surface of cancer cells. Thus, targeting costimulatory pathways represent an attractive therapeutic strategy to enhance the antitumor immunity in several human cancers. Here, latest therapeutic approaches targeting costimulatory molecules will be described.

Gene therapy for lung neoplasms

Both advanced-stage lung cancer and malignant pleural mesothelioma are associated with a poor prognosis. Advances in treatment regimens for both diseases have had only a modest effect on their progressive course. Gene therapy for thoracic malignancies represents a novel therapeutic approach and has been evaluated in several clinical trials. Strategies have included induction of apoptosis, tumor suppressor gene replacement, suicide gene expression, cytokine-based therapy, various vaccination approaches, and adoptive transfer of modified immune cells. This review considers the clinical results, limitations, and future directions of gene therapy trials for thoracic malignancies.

Gp96 SIV Ig immunization induces potent polyepitope specific, multifunctional memory responses in rectal and vaginal mucosa

The ER-resident chaperone gp96, when released by cell lysis, induces an immunogenic chemokine signature and causes innate immune activation of DC and NK cells. Here we show that intraperitoneal immunization with a genetically engineered, secreted form of gp96, gp96-Ig chaperoning SIV antigens, induces high levels of antigen specific CD8 CTL in the rectal and vaginal mucosa of Rhesus macaques. The frequency of SIV Gag- and SIV Tat-tetramer positive CD8 CTL in the intestinal mucosa reached 30-50% after the third immunization. Tetramer positive CD8 CTL expressed appropriate functional (granzyme B) and migration markers (CD103). The polyepitope specificity of the mucosal CD8 and CD4 response is evident from a strong, multifunctional cytokine response upon stimulation with peptides covering the gag, tat and env proteins. Induction of powerful mucosal effector CD8 CTL responses by cell-based gp96(SIV)-Ig immunization may provide a pathway to the development of safe and effective SIV/HIV vaccines.

Immunotherapy as a strategy for the treatment of non-small-cell lung cancer

Positive modulation of a patient's immune system to produce antitumor immunity is an attractive strategy that may improve the dismal outcomes typically associated with non-small-cell lung cancer (NSCLC). Using methods that either augment specific antitumor immunity or positively influence the patient's immune system to allow the de novo generation of immunity to encompass current strategies used in recent clinical trials of NSCLC. Encouraging results of Phase II trials in antigen-specific immunotherapy have led to three subsequent Phase III trials, which are currently enrolling. Results of these trials will improve our understanding of the role that immunotherapy plays in the treatment of NSCLC. Successful application of a humoral vaccine in Cuba led to its approval for the treatment of advanced NSCLC patients in that country. To date, trials involving nonspecific immunotherapeutic interventions have failed to improve outcomes in NSCLC and may indicate a need to combine them with antigen-specific vaccines. Although these trials will greatly advance our knowledge of NSCLC immunotherapy, we believe truly efficacious immunotherapy may only result from implementation of strategies to both augment antitumor immunity and counteract tumor-mediated immunosuppression.

MHC II lung cancer vaccines prime and boost tumor-specific CD4+ T cells that cross-react with multiple histologic subtypes of nonsmall cell lung cancer cells

Nonsmall cell lung cancer (NSCLC) is the major cause of lung cancer-related deaths in the United States. We are developing cell-based vaccines as a new approach for the treatment of NSCLC. NSCLC is broadly divided into 3 histologic subtypes: adenocarcinoma, squamous cell carcinoma and large cell carcinoma. Since these subtypes are derived from the same progenitor cells, we hypothesized that they share common tumor antigens, and vaccines that induce immune reactivity against 1 subtype may also induce immunity against other subtypes. Our vaccine strategy has focused on activating tumor-specific CD4(+) T cells, a population of lymphocytes that facilitates the optimal activation of effector and memory cytotoxic CD8(+) T cells. We now report that our NSCLC MHC II vaccines prepared from adeno, squamous or large cell carcinomas each activate CD4(+) T cells that cross-react with the other NSCLC subtypes and do not react with HLA-DR-matched normal lung fibroblasts or other HLA-DR-matched nonlung tumor cells. Using MHC II NSCLC vaccines expressing the DR1, DR4, DR7 or DR15 alleles, we also demonstrate that antigens shared among the different subtypes are presented by multiple HLA-DR alleles. Therefore, MHC II NSCLC vaccines expressing a single HLA-DR allele activate NSCLC-specific CD4(+) T cells that react with the 3 major classes of NSCLC, and the antigens recognized by the activated T cells are presented by several common HLA-DR alleles, suggesting that the MHC II NSCLC vaccines are potential immunotherapeutics for a range of NSCLC patients.

Current status of vascular endothelial growth factor inhibition in age-related macular degeneration

Angiogenesis, the process by which new vessels are created from pre-existing vasculature, has become the subject of intense research in recent years. Increased rates of angiogenesis are associated with several disease states, including cancer, age-related macular degeneration (AMD), psoriasis, rheumatoid arthritis, and diabetic retinopathy. Vascular endothelial growth factor (VEGF) is an important modulator of angiogenesis, and has been implicated in the pathology of a number of conditions, including AMD, diabetic retinopathy, and cancer. AMD is a progressive disease of the macula and the third major cause of blindness worldwide. If not treated appropriately, AMD can progress to involve both eyes. Until recently, the treatment options for AMD have been limited, with photodynamic therapy (PDT) the mainstay of treatment. Although PDT is effective at slowing disease progression, it rarely results in improved vision. Several therapies have been or are now being developed for neovascular AMD, with the goal of inhibiting VEGF. These VEGF inhibitors include the RNA aptamer pegaptanib, partial and full-length antibodies ranibizumab and bevacizumab, the VEGF receptor decoy aflibercept, small interfering RNA-based therapies bevasiranib and AGN 211745, sirolimus, and tyrosine kinase inhibitors, including vatalanib, pazopanib, TG 100801, TG 101095, AG 013958, and AL 39324. At present, established therapies have met with great success in reducing the vision loss associated with neovascular AMD, whereas those still under investigation offer the potential for further advances. In AMD patients, these therapies slow the rate of vision loss and in some cases increase visual acuity. Although VEGF-inhibitor therapies are a milestone in the treatment of these disease states, several concerns need to be addressed before their impact can be fully realized.

Current vaccine updates for lung cancer

Current treatments for lung cancer are far from optimal. Several immunotherapeutic strategies involving vaccines incorporating different tumor-associated antigens to induce immune responses against tumors are being tested in clinical trials internationally. Although small, benefits have indeed been observed from the early studies of these vaccines, and the future is looking brighter for lung cancer patients as a handful of these immunotherapies reach Phase III trials. In addition, optimizing the induced immune response by these vaccines has become a priority, and a number of techniques are being considered, including addition of adjuvants and combining vaccines, which affect synergy based on their mechanism of action. This review is an update on the current vaccines in production, the benefits observed from their most recent studies, and the upcoming plans for improvements in these immunotherapies.

Gene therapy for mesothelioma and lung cancer

Both malignant pleural mesothelioma and advanced stage lung cancer are associated with a poor prognosis. Unfortunately, current treatment regimens have had only a modest effect on their progressive course. Gene therapy for thoracic malignancies represents a novel therapeutic approach and has been evaluated in a number of clinical trials over the last two decades. Using viral vectors or anti-sense RNA, strategies have included induction of apoptosis, tumor suppressor gene replacement, suicide gene expression, cytokine-based therapy, various vaccination approaches, and adoptive transfer of modified immune cells. This review will consider the clinical results, limitations, and future directions of gene therapy trials for thoracic malignancies.

Cellular immunotherapy of cancer

Standard therapies for many common cancers remain toxic and are often ineffective. Cellular immunotherapy has the potential to be a highly targeted alternative, with low toxicity to normal tissues but a high capacity to eradicate tumor. In this chapter we describe approaches that generate cellular therapies using active immunization with cells, proteins, peptides, or nucleic acids, as well as efforts that use adoptive transfer of effector cells that directly target antigens on malignant cells. Many of these approaches are proving successful in hematologic malignancy and in melanoma. In this chapter we discuss the advantages and limitations of each and how over the next decade investigators will attempt to broaden their reach, increase their efficacy, and simplify their application.

Overview of Tumor Cell–Based Vaccines

Whole-cell tumor vaccines have been investigated for more than 20 years for their efficacy in both preclinical models and in clinical trials in humans. There are clear advantages of whole-cell/polyepitope vaccination over those types of immunotherapy that target specific epitopes. Multiple and unknown antigens may be targeted to both the innate and adaptive immune system, and this may be further augmented by genetic modification of the vaccine cells to provide cytokines and costimulation. In this review, we give an overview of the field including the preclinical and clinical advances using unmodified and modified tumor-cell vaccines.

Costimulatory and coinhibitory receptors in anti-tumor immunity

SUMMARY

Despite the expression of antigens by tumor cells, spontaneous immune-mediated rejection of cancer seems to be a rare event. T-cell receptor engagement by peptide/major histocompatibility complexes constitutes the main signal for the activation of naive T cells but is not sufficient to initiate a productive generation and maintenance of effector cells. Full activation of T cells requires additional signals driven by costimulatory molecules present on activated antigen-presenting cells but rarely on tumors. Following the discovery of B7-1 (CD80), several other costimulatory molecules have been shown to contribute to T-cell activation and have relevance for improving anti-tumor immunity. Moreover, increasing the understanding of coinhibitory receptors has highlighted key additional pathways that can dominantly inhibit anti-tumor T-cell function. Improving positive costimulation, and interfering with negative regulation, continues to represent an attractive immunotherapeutic approach for the treatment of cancer. This review focuses upon those pathways with the highest potential for clinical application in human cancer patients.

Memory T cells need CD28 costimulation to remember

The activation and expansion of naïve T cells require costimulatory signals provided by CD28 and TNF family members. In contrast, for many years it was believed that memory T cells do not require CD28 costimulation for expansion during secondary responses. This was based on in vitro experiments that suggested the re-activation of memory T cells is somewhat independent of costimulation. Recent in vivo evidence, however, has challenged this and shown that both CD4+ and CD8+ memory T cells require CD28 costimulation for maximal expansion and pathogen clearance. This requirement has important implications for host immunity, vaccine development and immunotherapeutics.

Respiratory Homeostasis and Exploitation of the Immune System for Lung Cancer Vaccines

Lung cancer is the leading cause of all cancer deaths in the US. The international scientific and clinical community has made significant advances toward understanding specific molecular mechanisms underlying lung carcinogenesis; however, despite these insights and advances in surgery and chemoradiotherapy, the prognosis for non-small-cell lung cancer (NSCLC) remains poor. Nonetheless, significant effort is being focused on advancing translational research evaluating the efficacy of novel targeted therapeutic strategies for lung cancer. Illustrative examples of this include antagonists of the epidermal growth factor receptor (EGFR), tyrosine kinase inhibitors (TKIs) such as gefitinib and erlotinib, and a diverse assortment of anti-angiogenic compounds targeting growth factors and/or their receptors that regulate tumor-associated angiogenic programs. In addition, with the increased awareness of the significant role chronically activated leukocytes play as potentiators of solid-tumor development, the role of innate and adaptive immune cells as regulators of lung carcinogenesis is being examined. While some of these studies are examining how novel therapeutic strategies may enhance the efficacy of lung cancer vaccines, others are evaluating the intrinsic characteristics of the immune response to lung cancer in order to identify rate-limiting molecular and/or cellular programs to target with novel anticancer therapeutics. In this article, we explore important aspects of the immune system and its role in regulating normal respiratory homeostasis compared with the immune response accompanying development of lung cancer. These hallmarks are then discussed in the context of recent efforts to develop lung cancer vaccines, where we have highlighted important concepts that must be taken into consideration for future development of novel therapeutic strategies and clinical trials assessing their efficacy.

Gene immunotherapy for non-small cell lung cancer

Historically, limited results have been observed with immunity in non-small cell lung cancer (NSCLC). In the last 5 years, however, several immune-stimulating products have demonstrated enhancement of tumor antigen recognition through activation of dendritic cell-involved processes. Moreover, clinical benefit has been demonstrated in subsets of patients, justifying ongoing phase III investigation. Results of key gene immunotherapies being tested in NSCLC are reviewed. Preliminary results in advanced NSCLC suggest evidence of well-tolerated immune activation with suggested evidence of clinical benefit with respect to survival and response.

Active specific immunotherapy and cell-transfer therapy for the treatment of non-small cell lung cancer

Lung cancer is an intractable disease urgently requiring more effective treatment approaches. The potential of immunotherapy in this context remains promising, although presently there are no satisfactory protocols available for lung cancer. However, encouraging evidence of clinical benefits from immunotherapy is beginning to accumulate in several lung cancer trials. Better understanding of tumor-specific immune responses, identifying tumor-associated antigens, and manipulating the immunoregulatory environment of the tumor is likely to further increase the efficacy of immune-mediated cancer therapies. Here, we review recent advances in cellular immunotherapy and vaccines for lung cancer, emphasizing an important paradigm shift in the analysis of clinical benefit away from "tumor response" towards "patient response".

The complex role of B7 molecules in tumor immunology

T-cell activation requires the interaction of the T-cell receptor with a cognate major histocompatibility complex (MHC)-peptide complex. Initiated by antigen engagement, the adaptive immune response is orchestrated by a complex balance between stimulatory and inhibitory signals that are predominantly controlled by members of the B7 family. Here, we review the current knowledge on B7 family members concerning their constitutive and regulated expression, modulation of the immune response and their role in the evasion of host immune surveillance. We also discuss recent therapeutic strategies that aim to improve immune-cell recognition of tumors and induce tolerance to autoreactive immune responses in normal tissues by manipulating B7 functions.