Personalized neoantigen vaccination with synthetic long peptides: recent advances and future perspectives

Cracking the Codes behind Cancer Cells' Immune Evasion

Immune evasion is a key phenomenon in understanding tumor recurrence, metastasis, and other critical steps in tumor progression. The tumor microenvironment (TME) is in constant flux due to the tumor's ability to release signals that affect it, while immune cells within it can impact cancer cell behavior. Cancer cells undergo several changes, which can change the enrichment of different immune cells and modulate the activity of existing immune cells in the tumor microenvironment. Cancer cells can evade immune surveillance by downregulating antigen presentation or expressing immune checkpoint molecules. High levels of tumor-infiltrating lymphocytes (TILs) correlate with better outcomes, and robust immune responses can control tumor growth. On the contrary, increased enrichment of Tregs, myeloid-derived suppressor cells, and M2-like anti-inflammatory macrophages can hinder effective immune surveillance and predict poor prognosis. Overall, understanding these immune evasion mechanisms guides therapeutic strategies. Researchers aim to modulate the TME to enhance immune surveillance and improve patient outcomes. In this review article, we strive to summarize the composition of the tumor immune microenvironment, factors affecting the tumor immune microenvironment (TIME), and different therapeutic modalities targeting the immune cells. This review is a first-hand reference to understand the basics of immune surveillance and immune evasion.

Gemogenovatucel-T (Vigil): bi-shRNA plasmid-based targeted immunotherapy

We describe in this review the historical evidence leading up to the concept and design of Vigil and subsequent clinical applications including safety and efficacy in a randomized, controlled Phase IIB trial. Vigil (gemogenovatucel-T) is a unique triple function targeted immunotherapy that demonstrates preclinical and clinical systemic anticancer activity. Construction of Vigil involves harvest of autologous malignant tissue for neoantigen targeting (ideally containing clonal neoantigens) followed by a two-day process involving transfection with a plasmid to provide a permissive 'training environment' for the patient's immune system. Transfected plasmid components contain an expressive human GMCSF DNA segment to enhance anticancer immune functional response and a second component expressing bi-shRNAfurin which reduces TGFβ isomers (TGFβ1 and TGFβ2) thereby reducing cancer inhibition of the targeted immune response. Results generated to date justify advancement to confirmatory clinical trials supporting product regulatory approval.

Application of biomimetic nanovaccines in cancer immunotherapy: A useful strategy to help combat immunotherapy resistance

Breakthroughs in actual clinical applications have begun through vaccine-based cancer immunotherapy, which uses the body's immune system, both humoral and cellular, to attack malignant cells and fight diseases. However, conventional vaccine approaches still face multiple challenges eliciting effective antigen-specific immune responses, resulting in immunotherapy resistance. In recent years, biomimetic nanovaccines have emerged as a promising alternative to conventional vaccine approaches by incorporating the natural structure of various biological entities, such as cells, viruses, and bacteria. Biomimetic nanovaccines offer the benefit of targeted antigen-presenting cell (APC) delivery, improved antigen/adjuvant loading, and biocompatibility, thereby improving the sensitivity of immunotherapy. This review presents a comprehensive overview of several kinds of biomimetic nanovaccines in anticancer immune response, including cell membrane-coated nanovaccines, self-assembling protein-based nanovaccines, extracellular vesicle-based nanovaccines, natural ligand-modified nanovaccines, artificial antigen-presenting cells-based nanovaccines and liposome-based nanovaccines. We also discuss the perspectives and challenges associated with the clinical translation of emerging biomimetic nanovaccine platforms for sensitizing cancer cells to immunotherapy.

Development and Clinical Applications of Therapeutic Cancer Vaccines with Individualized and Shared Neoantigens

Neoantigens, presented as peptides on the surfaces of cancer cells, have recently been proposed as optimal targets for immunotherapy in clinical practice. The promising outcomes of neoantigen-based cancer vaccines have inspired enthusiasm for their broader clinical applications. However, the individualized tumor-specific antigens (TSA) entail considerable costs and time due to the variable immunogenicity and response rates of these neoantigens-based vaccines, influenced by factors such as neoantigen response, vaccine types, and combination therapy. Given the crucial role of neoantigen efficacy, a number of bioinformatics algorithms and pipelines have been developed to improve the accuracy rate of prediction through considering a series of factors involving in HLA-peptide-TCR complex formation, including peptide presentation, HLA-peptide affinity, and TCR recognition. On the other hand, shared neoantigens, originating from driver mutations at hot mutation spots (e.g., KRASG12D), offer a promising and ideal target for the development of therapeutic cancer vaccines. A series of clinical practices have established the efficacy of these vaccines in patients with distinct HLA haplotypes. Moreover, increasing evidence demonstrated that a combination of tumor associated antigens (TAAs) and neoantigens can also improve the prognosis, thus expand the repertoire of shared neoantigens for cancer vaccines. In this review, we provide an overview of the complex process involved in identifying personalized neoantigens, their clinical applications, advances in vaccine technology, and explore the therapeutic potential of shared neoantigen strategies.

Emerging advances in delivery systems for mRNA cancer vaccines

The success of lipid nanoparticles (LNPs) in treating COVID-19 promotes further research of mRNA vaccines for cancer vaccination. Aiming at overcoming the constraints of currently available mRNA carriers, various alternative nano-vectors have been developed for delivering tumor antigen encoding mRNA and showed versatility to induce potent anti-tumor immunity. The rationally designed nano-vaccines increase the immune activation capacity of the mRNA vaccines by promoting crucial aspects including mRNA stability, cellular uptake, endosomal escape and targeting of immune cells or organs. Herein, we summarized the research progress of various mRNA based nano-vaccines that have been reported for cancer vaccination, including LNPs, lipid enveloped hybrid nanoparticles, polymeric nanoparticles etc. Several strategies that have been reported for further enhancing the immune stimulation efficacy of mRNA nano-vaccines, including developing nano-vaccines for co-delivering adjuvants, combination of immune checkpoint inhibitors, and optimizing the injection routes for boosting immune responses, have been reviewed. The progress of mRNA nano-vaccines in clinical trials and the prospect of the mRNA vaccines for cancer vaccination are also discussed.

Engineered Bacteriophage-Based In Situ Vaccine Remodels a Tumor Microenvironment and Elicits Potent Antitumor Immunity

In situ vaccines (ISVs) utilize the localized delivery of chemotherapeutic agents or radiotherapy to stimulate the release of endogenous antigens from tumors, thereby eliciting systemic and persistent immune activation. Recently, a bioinspired ISV strategy has attracted tremendous attention due to its features such as an immune adjuvant effect and genetic plasticity. M13 bacteriophages are natural nanomaterials with intrinsic immunogenicity, genetic flexibility, and cost-effectiveness for large-scale production, demonstrating the potential for application in cancer vaccines. In this study, we propose an ISV based on the engineered M13 bacteriophage targeting CD40 (M13CD40) for dendritic cell (DC)-targeted immune stimulation, named H-GM-M13CD40. We induce immunogenic cell death and release tumor antigens through local delivery of (S)-10-hydroxycamptothecin (HCPT), followed by intratumoral injection of granulocyte-macrophage colony stimulating factor (GM-CSF) and M13CD40 to enhance DC recruitment and activation. We demonstrate that this ISV strategy can result in significant accumulation and activation of DCs at the tumor site, reversing the immunosuppressive tumor microenvironment. In addition, H-GM-M13CD40 can synergize with the PD-1 blockade and induce abscopal effects in cold tumor models. Overall, our study verifies the immunogenicity of the engineered M13CD40 bacteriophage and provides a proof of concept that the engineered M13CD40 phage can function as an adjuvant for ISVs.

Cyclodextrin microneedles for the delivery of a nanoparticle-based peptide antigen vaccine

In recent years, microneedles (MNs) have gained considerable interest in drug formulation due to their non-invasive and patient-friendly nature. Dissolving MNs have emerged as a promising approach to enhance drug delivery across the skin in a painless manner without generating sharp waste and providing the possibility for self-administration. Cyclodextrins, a group of cyclic oligosaccharides, are well-established in pharmaceutical products due to their safety and unique ability to form inclusion complexes with various drug molecules. In this manuscript, we report the development and characterization of dissolving MNs composed of cyclodextrins for intradermal delivery of a cyclodextrin-based nanoparticulate vaccine. Different cyclodextrins were tested and the most promising candidates were fabricated into MNs by micromolding. The MNs' piercing effectiveness and drug permeation across the skin were tested ex vivo. Furthermore, in vivo studies were carried out to assess the skin's tolerance to cyclodextrin-based MNs, and to evaluate the immune response using a model peptide antigen in a mouse model. The data revealed that the MNs were well-tolerated and effective, even leading to dose-sparing effects. This study highlights the potential of cyclodextrin-based dissolving MNs as a versatile platform for intradermal vaccine delivery, providing a compatible matrix for nanoparticulate formulations to enhance immune responses.

Recent Findings on Therapeutic Cancer Vaccines: An Updated Review

Cancer remains one of the global leading causes of death and various vaccines have been developed over the years against it, including cell-based, nucleic acid-based, and viral-based cancer vaccines. Although many vaccines have been effective in in vivo and clinical studies and some have been FDA-approved, there are major limitations to overcome: (1) developing one universal vaccine for a specific cancer is difficult, as tumors with different antigens are different for different individuals, (2) the tumor antigens may be similar to the body's own antigens, and (3) there is the possibility of cancer recurrence. Therefore, developing personalized cancer vaccines with the ability to distinguish between the tumor and the body's antigens is indispensable. This paper provides a comprehensive review of different types of cancer vaccines and highlights important factors necessary for developing efficient cancer vaccines. Moreover, the application of other technologies in cancer therapy is discussed. Finally, several insights and conclusions are presented, such as the possibility of using cold plasma and cancer stem cells in developing future cancer vaccines, to tackle the major limitations in the cancer vaccine developmental process.

From structural design to delivery: mRNA therapeutics for cancer immunotherapy

mRNA therapeutics have emerged as powerful tools for cancer immunotherapy in accordance with their superiority in expressing all sequence-known proteins in vivo. In particular, with a small dosage of delivered mRNA, antigen-presenting cells (APCs) can synthesize mutant neo-antigens and multi-antigens and present epitopes to T lymphocytes to elicit antitumor effects. In addition, expressing receptors like chimeric antigen receptor (CAR), T-cell receptor (TCR), CD134, and immune-modulating factors including cytokines, interferons, and antibodies in specific cells can enhance immunological response against tumors. With the maturation of in vitro transcription (IVT) technology, large-scale and pure mRNA encoding specific proteins can be synthesized quickly. However, the clinical translation of mRNA-based anticancer strategies is restricted by delivering mRNA into target organs or cells and the inadequate endosomal escape efficiency of mRNA. Recently, there have been some advances in mRNA-based cancer immunotherapy, which can be roughly classified as modifications of the mRNA structure and the development of delivery systems, especially the lipid nanoparticle platforms. In this review, the latest strategies for overcoming the limitations of mRNA-based cancer immunotherapies and the recent advances in delivering mRNA into specific organs and cells are summarized. Challenges and opportunities for clinical applications of mRNA-based cancer immunotherapy are also discussed.

Nanomaterial Delivery Vehicles for the Development of Neoantigen Tumor Vaccines for Personalized Treatment

Tumor vaccines have been considered a promising therapeutic approach for treating cancer in recent years. With the development of sequencing technologies, tumor vaccines based on neoantigens or genomes specifically expressed in tumor cells, mainly in the form of peptides, nucleic acids, and dendritic cells, are beginning to receive widespread attention. Therefore, in this review, we have introduced different forms of neoantigen vaccines and discussed the development of these vaccines in treating cancer. Furthermore, neoantigen vaccines are influenced by factors such as antigen stability, weak immunogenicity, and biosafety in addition to sequencing technology. Hence, the biological nanomaterials, polymeric nanomaterials, inorganic nanomaterials, etc., used as vaccine carriers are principally summarized here, which may contribute to the design of neoantigen vaccines for improved stability and better efficacy.

Challenges in developing personalized neoantigen cancer vaccines

The recent success of cancer immunotherapies has highlighted the benefit of harnessing the immune system for cancer treatment. Vaccines have a long history of promoting immunity to pathogens and, consequently, vaccines targeting cancer neoantigens have been championed as a tool to direct and amplify immune responses against tumours while sparing healthy tissue. In recent years, extensive preclinical research and more than one hundred clinical trials have tested different strategies of neoantigen discovery and vaccine formulations. However, despite the enthusiasm for neoantigen vaccines, proof of unequivocal efficacy has remained beyond reach for the majority of clinical trials. In this Review, we focus on the key obstacles pertaining to vaccine design and tumour environment that remain to be overcome in order to unleash the true potential of neoantigen vaccines in cancer therapy.

RNA Origami Functions as a Self-Adjuvanted Nanovaccine Platform for Cancer Immunotherapy

Peptide-based vaccines have been widely investigated in cancer immunotherapy. Despite their high specificity, safety, and low production cost, these vaccines have shown limited success in clinical studies, owing to their poor immunogenicity. Extensive efforts have been devoted to increasing the immunogenicity of peptide vaccines by mixing peptides with adjuvants and/or promoting their delivery to tumor-draining lymph nodes (TdLNs) for better antigen presentation by and maturation of dendritic cells. Among these efforts, the exploration of various nanoparticles has been at the forefront of the rational design and construction of peptide-based vaccines. Here, we present a nanovaccine platform that is built on a self-assembled RNA origami (RNA-OG) nanostructure. As previously reported, this RNA-OG nanostructure is a potent toll-like receptor (TLR)3 agonist. In addition, due to its robust synthesis and versatility in modification, RNA-OG could be readily linked to peptides of interest. Thus, these RNA-OG nanostructures function as adjuvanted nanocarriers to construct RNA-OG-peptide nanovaccines that are uniform in size, consistent in peptide loading, and highly stable. Here, we demonstrate that the assembled RNA-OG-peptide nanovaccines induced dendritic cell maturation, reduced tumor-mediated immunosuppression, and mobilized tumor-specific CD8+ T cell responses at the tumor site. Together, these actions led to the elicitation of an effective antitumor immunity that increased the survival of tumor-bearing mice. The combination of RNA-OG-based nanovaccines with the α-PD-1 immune checkpoint blockade further enhanced the immunity. Hence, our RNA-OG nanostructures represent a robust, simple, and highly effective platform to empower peptide-based vaccines for cancer immunotherapy.

Targeting Tumor Heterogeneity with Neoantigen-Based Cancer Vaccines

Neoantigen-based cancer vaccines have emerged as a promising immunotherapeutic approach to treat cancer. Nevertheless, the high degree of heterogeneity in tumors poses a significant hurdle for developing a vaccine that targets the therapeutically relevant neoantigens capable of effectively stimulating an immune response as each tumor contains numerous unique putative neoantigens. Understanding the complexities of tumor heterogeneity is crucial for the development of personalized neoantigen-based vaccines, which hold the potential to revolutionize cancer treatment and improve patient outcomes. In this review, we discuss recent advancements in the design of neoantigen-based cancer vaccines emphasizing the identification, validation, formulation, and targeting of neoantigens while addressing the challenges posed by tumor heterogeneity. The review highlights the application of cutting-edge approaches, such as single-cell sequencing and artificial intelligence to identify immunogenic neoantigens, while outlining current limitations and proposing future research directions to develop effective neoantigen-based vaccines.

TLR9 plus STING Agonist Adjuvant Combination Induces Potent Neopeptide T Cell Immunity and Improves Immune Checkpoint Blockade Efficacy in a Tumor Model

Immune checkpoint blockade (ICB) immunotherapies have emerged as promising strategies for the treatment of cancer; however, there remains a need to improve their efficacy. Determinants of ICB efficacy are the frequency of tumor mutations, the associated neoantigens, and the T cell response against them. Therefore, it is expected that neoantigen vaccinations that boost the antitumor T cell response would improve ICB therapy efficacy. The aim of this study was to develop a highly immunogenic vaccine using pattern recognition receptor agonists in combination with synthetic long peptides to induce potent neoantigen-specific T cell responses. We determined that the combination of the TLR9 agonist K-type CpG oligodeoxynucleotides (K3 CpG) with the STING agonist c-di-AMP (K3/c-di-AMP combination) significantly increased dendritic cell activation. We found that immunizing mice with 20-mer of either an OVA peptide, low-affinity OVA peptides, or neopeptides identified from mouse melanoma or lung mesothelioma, together with K3/c-di-AMP, induced potent Ag-specific T cell responses. The combined K3/c-di-AMP adjuvant formulation induced 10 times higher T cell responses against neopeptides than the TLR3 agonist polyinosinic:polycytidylic acid, a derivative of which is the leading adjuvant in clinical trials of neoantigen peptide vaccines. Moreover, we demonstrated that our K3/c-di-AMP vaccine formulation with 20-mer OVA peptide was capable of controlling tumor growth and improving survival in B16-F10-OVA tumor-bearing C57BL/6 mice and synergized with anti-PD-1 treatment. Together, our findings demonstrate that the K3/c-di-AMP vaccine formulation induces potent T cell immunity against synthetic long peptides and is a promising candidate to improve neoantigen vaccine platform.

Therapeutic cancer vaccines: advancements, challenges, and prospects

With the development and regulatory approval of immune checkpoint inhibitors and adoptive cell therapies, cancer immunotherapy has undergone a profound transformation over the past decades. Recently, therapeutic cancer vaccines have shown promise by eliciting de novo T cell responses targeting tumor antigens, including tumor-associated antigens and tumor-specific antigens. The objective was to amplify and diversify the intrinsic repertoire of tumor-specific T cells. However, the complete realization of these capabilities remains an ongoing pursuit. Therefore, we provide an overview of the current landscape of cancer vaccines in this review. The range of antigen selection, antigen delivery systems development the strategic nuances underlying effective antigen presentation have pioneered cancer vaccine design. Furthermore, this review addresses the current status of clinical trials and discusses their strategies, focusing on tumor-specific immunogenicity and anti-tumor efficacy assessment. However, current clinical attempts toward developing cancer vaccines have not yielded breakthrough clinical outcomes due to significant challenges, including tumor immune microenvironment suppression, optimal candidate identification, immune response evaluation, and vaccine manufacturing acceleration. Therefore, the field is poised to overcome hurdles and improve patient outcomes in the future by acknowledging these clinical complexities and persistently striving to surmount inherent constraints.

Recruiting In Vitro Transcribed mRNA against Cancer Immunotherapy: A Contemporary Appraisal of the Current Landscape

Over 100 innovative in vitro transcribed (IVT)-mRNAs are presently undergoing clinical trials, with a projected substantial impact on the pharmaceutical market in the near future. Τhe idea behind this is that after the successful cellular internalization of IVT-mRNAs, they are subsequently translated into proteins with therapeutic or prophylactic relevance. Simultaneously, cancer immunotherapy employs diverse strategies to mobilize the immune system in the battle against cancer. Therefore, in this review, the fundamental principles of IVT-mRNA to its recruitment in cancer immunotherapy, are discussed and analyzed. More specifically, this review paper focuses on the development of mRNA vaccines, the exploitation of neoantigens, as well as Chimeric Antigen Receptor (CAR) T-Cells, showcasing their clinical applications and the ongoing trials for the development of next-generation immunotherapeutics. Furthermore, this study investigates the synergistic potential of combining the CAR immunotherapy and the IVT-mRNAs by introducing our research group novel, patented delivery method that utilizes the Protein Transduction Domain (PTD) technology to transduce the IVT-mRNAs encoding the CAR of interest into the Natural Killer (NK)-92 cells, highlighting the potential for enhancing the CAR NK cell potency, efficiency, and bioenergetics. While IVT-mRNA technology brings exciting progress to cancer immunotherapy, several challenges and limitations must be acknowledged, such as safety, toxicity, and delivery issues. This comprehensive exploration of IVT-mRNA technology, in line with its applications in cancer therapeutics, offers valuable insights into the opportunities and challenges in the evolving landscape of cancer immunotherapy, setting the stage for future advancements in the field.

Development of dendritic cell loaded MAGE-A2 long peptide; a potential target for tumor-specific T cell-mediated prostate cancer immunotherapy

BACKGROUND

Prostate cancer (PCa) is the second leading cause of cancer-related deaths among men worldwide. Immunotherapy is an emerging treatment modality for cancers that harnesses the immune system's ability to eliminate tumor cells. In particular, dendritic cell (DC) vaccines, have demonstrated promise in eliciting a tumor-specific immune response. In this study, we investigated the potential of using DCs loaded with the MAGE-A2 long peptide to activate T cell cytotoxicity toward PCa cell lines.

METHODS

Here, we generated DCs from monocytes and thoroughly characterized their phenotypic and functional properties. Then, DCs were pulsed with MAGE-A2 long peptide (LP) as an antigen source, and monitored for their transition from immature to mature DCs by assessing the expression levels of several costimulatory and maturation molecules like CD14, HLA-DR, CD40, CD11c, CD80, CD83, CD86, and CCR7. Furthermore, the ability of MAGE-A2 -LP pulsed DCs to stimulate T cell proliferation in a mixed lymphocyte reaction (MLR) setting and induction of cytotoxic T cells (CTLs) in coculture with autologous T cells were examined. Finally, CTLs were evaluated for their capacity to produce interferon-gamma (IFN-γ) and kill PCa cell lines (PC3 and LNCaP).

RESULTS

The results demonstrated that the antigen-pulsed DCs exhibited a strong ability to stimulate the expansion of T cells. Moreover, the induced CTLs displayed substantial cytotoxicity against the target cells and exhibited increased IFN-γ production during activation compared to the controls.

CONCLUSIONS

Overall, this innovative approach proved efficacious in targeting PCa cell lines, showcasing its potential as a foundation for the development and improved PCa cancer immunotherapy.

Sec22b and Stx4 Depletion Has No Major Effect on Cross-Presentation of PLGA Microsphere-Encapsulated Antigen and a Synthetic Long Peptide In Vitro

The induction of CTL responses by vaccines is important to combat infectious diseases and cancer. Biodegradable poly(lactic-co-glycolic acid) (PLGA) microspheres and synthetic long peptides are efficiently internalized by professional APCs and prime CTL responses after cross-presentation of Ags on MHC class I molecules. Specifically, they mainly use the cytosolic pathway of cross-presentation that requires endosomal escape, proteasomal processing, and subsequent MHC class I loading of Ags in the endoplasmic reticulum (ER) and/or the endosome. The vesicle SNARE protein Sec22b has been described as important for this pathway by mediating vesical trafficking for the delivery of ER-derived proteins to the endosome. As this function has also been challenged, we investigated the role of Sec22b in cross-presentation of the PLGA microsphere-encapsulated model Ag OVA and a related synthetic long peptide. Using CRISPR/Cas9-mediated genome editing, we generated Sec22b knockouts in two murine C57BL/6-derived APC lines and found no evidence for an essential role of Sec22b. Although pending experimental evidence, the target SNARE protein syntaxin 4 (Stx4) has been suggested to promote cross-presentation by interacting with Sec22b for the fusion of ER-derived vesicles with the endosome. In the current study, we show that, similar to Sec22b, Stx4 knockout in murine APCs had very limited effects on cross-presentation under the conditions tested. This study contributes to characterizing cross-presentation of two promising Ag delivery systems and adds to the discussion about the role of Sec22b/Stx4 in related pathways. Our data point toward SNARE protein redundancy in the cytosolic pathway of cross-presentation.

Immunological analysis of hybrid neoantigen peptide encompassing class I/II neoepitope-pulsed dendritic cell vaccine

Neoantigens/ are tumor-specific antigens that evade central immune tolerance mechanisms in the thymus. Long-term tumor-specific cytotoxic T lymphocyte activity maintenance requires class II antigen-reactive CD4+ T cells. We had previously shown that intranodal vaccination with class I neoantigen peptide-pulsed dendritic cells (DCs) induced a robust immune response in a subset of patients with metastatic cancer. The present study aimed to perform a detailed ex vivo analysis of immune responses in four patients receiving an intranodal hybrid human leukocyte antigen class II neoantigen peptide encompassing a class I neoantigen epitope (hybrid neoantigen)-pulsed DC vaccine. After vaccination, strong T-cell reactions against the hybrid class II peptide and the class I-binding neoantigen peptide were observed in all four patients. We found that hybrid class II neoantigen peptide-pulsed DCs stimulated CD4+ T cells via direct antigen presentation and CD8+ T cells via cross-presentation. Further, we demonstrated that hybrid class II peptides encompassing multiple class I neoantigen epitope-pulsed DCs could present multiple class I peptides to CD8+ T cells via cross-presentation. Our findings provide insight into the mechanisms underlying hybrid neoantigen-pulsed DC vaccine therapy and suggest future neoantigen vaccine design.

Improvement in neoantigen prediction via integration of RNA sequencing data for variant calling

Introduction

Neoantigen-based immunotherapy has emerged as a promising strategy for improving the life expectancy of cancer patients. This therapeutic approach heavily relies on accurate identification of cancer mutations using DNA sequencing (DNAseq) data. However, current workflows tend to provide a large number of neoantigen candidates, of which only a limited number elicit efficient and immunogenic T-cell responses suitable for downstream clinical evaluation. To overcome this limitation and increase the number of high-quality immunogenic neoantigens, we propose integrating RNA sequencing (RNAseq) data into the mutation identification step in the neoantigen prediction workflow.

Methods

In this study, we characterize the mutation profiles identified from DNAseq and/or RNAseq data in tumor tissues of 25 patients with colorectal cancer (CRC). Immunogenicity was then validated by ELISpot assay using long synthesis peptides (sLP).

Results

We detected only 22.4% of variants shared between the two methods. In contrast, RNAseq-derived variants displayed unique features of affinity and immunogenicity. We further established that neoantigen candidates identified by RNAseq data significantly increased the number of highly immunogenic neoantigens (confirmed by ELISpot) that would otherwise be overlooked if relying solely on DNAseq data.

Discussion

This integrative approach holds great potential for improving the selection of neoantigens for personalized cancer immunotherapy, ultimately leading to enhanced treatment outcomes and improved survival rates for cancer patients.

Translatability scoring in prospective and retrospective COVID drug development cases

BACKGROUND

The ongoing pandemic of severe acute respiratory syndrome coronavirus 2 has led to an enormous surge of clinical research. So far, the speed and success rate of related drug development projects, especially of vaccines, is unprecedented. For the first time, this situation allowed for the opportunistic evaluation of a translatability score, originally proposed in 2009, in a prospective manner.

METHODS

Several vaccines and treatments under development in clinical phase III trials were selected for translational scoring with the translatability score. Six prospective and six retrospective case studies were performed. The scores had to be determined for a fictive date before any results of the phase III trial were reported in any media. Spearman correlation analysis and a Kruskal Wallis test were performed for statistical evaluation.

RESULTS

A significant correlation between the translatability scores and the clinical outcomes in translation was found, as judged on the basis of positive/intermediate/negative endpoint studies or market approval. The Spearman correlation analysis of all cases (r = 0.91, p < 0.001), the prospective cases alone (r = 0.93, p = 0.008), and the retrospective cases alone (r = 0.93, p = 0.008) showed a strong correlation between the score and outcome; R2 demonstrated a score-derived determination of outcomes by 86%.

CONCLUSIONS

The score detects strengths and weaknesses of a given project, resulting in the opportunity of selective amelioration of a project, as well as prospective portfolio risk balancing. Its substantial predictive value that has been demonstrated here for the first time could be of particular interest for biomedical industry (pharmaceutical and device manufacturers), funding agencies, venture capitalists, and researchers in the area. Future evaluations will have to address the generalizability of results obtained in an exceptional pandemic situation, and the potential adaptations of weighing factors/items to particular therapeutic areas.

Improved Survival of a HER2-Positive Metastatic Breast Cancer Patient Following a Personalized Peptide Immunization

Cancer neoantigens that arise from somatic mutations have emerged as important targets for personalized immunization. Here, we report an improved overall survival of a HER2-positive metastatic breast cancer patient using a bioinformatic-based personalized peptide immunization called BITAP (BioInformatic Tumor Address Peptides). The epitopes were predicted using our in-house bioinformatic pipeline, and the immunogenicity was tested by IFN-γ ELISPOT and intracellular cytokine staining assays. In total, a significant peptide-specific T-cell response was detected against 18 out of the 76 (≈24%) tested peptides. The patient's follow-up by measuring serologic markers showed a significant reduction in the tumor marker levels following BITAP immunization. Along with standard treatment, the patient treated with the BITAP showed stable disease with a remarkably improved overall survival, and no serious treatment-related adverse effects. In conclusion, our findings suggest that BITAP immunization is feasible, and safe, and may induce tumor regressions in patients with HER2-positive subsets of breast cancer.

Instigation of the epoch of nanovaccines in cancer immunotherapy

Cancer is an unprecedented proliferation of cells leading to abnormalities in differentiation and maturation. Treatment of primary and metastatic cancer is challenging. In addition to surgery, chemotherapy and radiation therapies have been conventionally used; however, they suffer from severe toxicity and non-specificity. Immunotherapy, the science of programming the body's own defense system against cancer has gained tremendous attention in the last few decades. However, partial immunogenic stimulation, premature degradation and inability to activate dendritic and helper T cells has resulted in limited clinical success. The era of nanomedicine has brought about several breakthroughs in various pharmaceutical and biomedical fields. Hereby, we review and discuss the interplay of tumor microenvironment (TME) and the immunological cascade and how they can be employed to develop nanoparticle-based cancer vaccines and immunotherapies. Nanoparticles composed of lipids, polymers and inorganic materials contain useful properties suitable for vaccine development. Proteinaceous vaccines derived from mammalian viruses, bacteriophages and plant viruses also have unique advantages due to their immunomodulation capabilities. This review accounts for all such considerations. Additionally, we explore how attributes of nanotechnology can be utilized to develop successful nanomedicine-based vaccines for cancer therapy. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Neoantigen vaccination augments antitumor effects of anti-PD-1 on mouse hepatocellular carcinoma

Immune checkpoint inhibitors are groundbreaking resources for cancer therapy. However, only a few patients with hepatocellular carcinoma (HCC) have shown positive responses to anti-PD-1 therapy. Neoantigens are sequence-altered proteins resulting from somatic mutations in cancer. This study identified the neoantigens of Hep-55.1C and Dt81 Hepa1-6 HCCs by comparing their whole exome sequences with those of a normal C57BL/6 mouse liver. Immunogenic long peptides were pooled as peptide vaccines. The vaccination elicited tumor-reactive immune responses in C57BL/6 mice, as demonstrated by IFN-γ ELISPOT and an in vitro killing assay of splenocytes. In the treatment of three mouse HCC models, combined neoantigen vaccination and anti-PD-1 resulted in more significant tumor regression than monotherapies. Flow cytometry of the tumor-infiltrating lymphocytes showed decreased Treg cells and monocytic myeloid-derived suppressor cells, increased CD8⁺ T cells, enhanced granzyme B expression, and reduced exhaustion-related markers PD-1 and Lag-3 on CD8⁺ T cells in the combination group. These findings provide a strong rationale for conducting clinical studies of using neoantigen vaccination in combination with anti-PD-1 to treat patients with HCC.

Application prospect of circular RNA-based neoantigen vaccine in tumor immunotherapy

Neoantigen is a protein produced by mutant gene, which is only expressed in tumor cells. It is an ideal target for therapeutic tumor vaccines. Although synthetic long peptide (SLP)-based neoantigen vaccine, DNA-based neoantigen vaccine, and mRNA-based neoantigen vaccine are all in the development stage, they have some inherent shortcomings. Therefore, researchers turned their attention to a new type of "non-coding RNA (ncRNA)", circular RNA (circRNA), for potential better choice. Because of its unique high stability and protein-coding capacity, circRNA is a promising target in the field of neoantigen vaccine. In this paper, we reviewed the feasibility of circRNA encoding neoantigens, summarized the construction process, explained the mechanism of circRNA vaccine in vitro, and discussed the advantages and disadvantages of circRNA vaccine and possible combination with other immunotherapies.

Insight on common forms of cutaneous head and neck carcinoma (Review)

To improve the outcome and quality of life for patients with head and neck carcinoma, an increasing amount of research has been performed on the particularities of this type of cancer and its treatment methods. Starting from clinical aspects, including histology and imaging features, up-to-date studies from different parts of the world have determined new data leading to a better understanding of the mechanisms behind the disease and proposed new treatment protocols. The head and neck areas are predisposed to almost all skin neoplasms, most commonly those related to ultraviolet exposure. Squamous cell carcinoma and basal cell carcinoma account for almost 90% of non-melanoma skin cancers in this region; therefore, reviewing the literature on cutaneous carcinomas of the head and neck area and sharing particular aspects of their physiopathology are beneficial for a great number of patients.

The long multi-epitope peptide vaccine combined with adjuvants improved the therapeutic effects in a glioblastoma mouse model

Emerging data have suggested that single short peptides have limited success as a cancer vaccine; however, extending the short peptides into longer multi-epitope peptides overcame the immune tolerance and induced an immune response. Moreover, the combination of adjuvants such as lenalidomide and anti-programmed cell death protein 1 (PD1) with a peptide vaccine showed potential vaccine effects in previous studies. Therefore, the effects of a long multi-epitope peptide vaccine in combination with lenalidomide and anti-PD1 were analyzed in this study. Long multi-epitope peptides from two MHCI peptides (BIRC597-104 and EphA2682-689) and the pan-human leukocyte antigen-DR isotype (HLA-DR) binding epitope (PADRE) were synthesized. The therapeutic effects of long multi-epitope peptides in combination with lenalidomide and anti-PD1 were confirmed in the murine GL261 intracranial glioma model. Immune cells’ distribution and responses to the long multi-epitope peptides in combination with these adjuvants were also estimated in the spleens, lymph nodes, and tumor tissues. The difference between long multi-epitope peptides and a cocktail of multi-epitope peptides combined with lenalidomide and anti-PD1 was also clarified. As a result, long multi-epitope peptides combined with lenalidomide and anti-PD1 prolonged the survival of mice according to the suppression of tumor growth in an intracranial mouse model. While long multi-epitope peptides combined with these adjuvants enhanced the percentages of activated and memory effector CD8+ T cells, the increase in percentages of regulatory T cells (Tregs) was observed in a cocktail of multi-epitope peptides combined with lenalidomide and anti-PD1 group in the tumors. Long multi-epitope peptides combined with these adjuvants also enhanced the function of immune cells according to the enhanced pro-inflammatory cytokines and cytotoxicity against GL261 cells in ex vivo. In conclusion, long multi-epitope peptides composed of MHCI peptides, BIRC5 and EphA2, and the MHCII peptide, PADRE, in combination with lenalidomide and anti-PD1 has the potential to improve the therapeutic effects of a vaccine against GBM.

Neoantigen Vaccines; Clinical Trials, Classes, Indications, Adjuvants and Combinatorial Treatments

Simple Summary

Personalized neoantigen vaccines are a diverse group of personally tailored cancer vaccines that strengthen patients´ own immune reaction against cancer antigens. We analyzed 147 neoantigen vaccine clinical trials from ClinicalTrials.gov database and showed that peptide vaccines were the dominating vaccine type, while there were multiple new neoantigen vaccine types in the field. We also showed that neoantigen vaccines were mostly used in the treatment of small cell lung cancer, non-small cell lung cancer, melanoma, and glioma. According to our results neoantigen vaccines work at their best when combined with other treatments such as immune checkpoint inhibitors, chemotherapy, and radiation therapy. The effect of some neoantigen vaccine types were also often promoted with adjuvant therapy where poly-ICLC were the most recurrent adjuvant choice.

Abstract

Personalized neoantigen vaccines are a highly specific cancer treatment designed to induce a robust cytotoxic T-cell attack against a patient’s cancer antigens. In this study, we searched ClinicalTrials.gov for neoantigen vaccine clinical trials and systematically analyzed them, a total of 147 trials. Peptide vaccines are the largest neoantigen vaccine type, comprising up to 41% of the clinical trials. However, mRNA vaccines are a growing neoantigen vaccine group, especially in the most recent clinical trials. The most common cancer types in the clinical trials are glioma, lung cancer, and malignant melanoma, being seen in more than half of the clinical trials. Small-cell lung cancer and non-small-cell lung cancer are the largest individual cancer types. According to the results from the clinical trials, neoantigen vaccines work best when combined with other cancer treatments, and popular combination treatments include immune checkpoint inhibitors, chemotherapy, and radiation therapy. Additionally, half of the clinical trials combined neoantigen vaccines with an adjuvant to boost the immune effects, with poly-ICLC being the most recurrent adjuvant choice. This study clarifies the rapid clinical trial development of personalized neoantigen vaccines as an emerging class of cancer treatment with increasingly diversified opportunities in classes, indications, and combinatorial treatments.

Landscape and progress of global peptide drugs in obstetrics and gynaecology

Peptides have gained popularity in the global market during recent years and have been placed between small molecule drugs and biologics. However, little is known about the comprehensive landscape of peptide drugs in obstetrics and gynaecology. Herein, we analysed new peptide drug-related clinical trials in obstetrics and gynaecology registered on ClinicalTrials.gov. The number and percentage were used for statistical analysis, and a time trend analysis was conducted by calculating the annual growth rate. We aimed to provide the first overview of the changing landscape and status of global peptide drugs in this prospective field, including exploring drug targets, the cutting-edge oncotherapy of peptide vaccines and peptide-drug conjugates, and unsolved challenges with oral administration.

The progress of peptide vaccine clinical trials in gynecologic oncology

Peptide vaccine are a type of immunotherapy that are synthesized according to the amino acid sequence of known or predicted tumor antigen epitopes. They are safe and well tolerated and have shown exciting results in gynecologic oncology. However, no peptide vaccine has yet been licensed in this field. This review examines peptide vaccine clinical trials in gynecology registered on ClinicalTrials.gov through January 1, 2022, analyzes the global progress and current achievements of peptide vaccines in gynecology, and explores the efforts focused on devising new methods to boost immunotherapeutic outcomes, including the use of adjuvants, multi-epitope vaccines, combinations of helper T cell epitopes, personalized peptide vaccines, synthetic long peptides, new peptide delivery, and combination therapy.

Therapy of genomic unstable solid tumours (WHO grade 3/4）in clinical stage III/IV using individualised neoantigen tumour peptides-INP trial (individualised neoantigen tumour peptides immunotherapy): study protocol for an open-label, non-randomised, prospective, single-arm trial

INTRODUCTION

Neoantigens derived from tumour somatic mutations are recognised as ideal vaccine targets. Tumour neoantigens have been studied in a wide range of tumours. Most of research on neoantigens has focused just on a unique tumour and a single mutated gene. Currently, a few studies have reported using a mixture of neoantigen peptides derived from multiple genetic mutation sites in the treatment of genomic unstable advanced solid malignancies. The trial aims to evaluate the safety and efficacy of individualised tumour neoantigen peptide mixtures in the treatment of genomic unstable advanced solid malignant tumours.

METHODS AND ANALYSIS

This is a prospective, non-randomised, open, single-centre, single-arm, phase I trial. Patients with genomic unstable advanced solid malignancies are eligible for study participations. 20 patients will be included in the trial. Through the whole exome and transcriptome sequencing analysis of the fresh blood and tumour tissues of the enrolled patients, the 20 25-33aa antigen peptides with the highest mutation scores of the patients will be screened out, and the corresponding new antigen peptides will be synthesised and prepared. Patients will be treated with their own individualised neoantigen polypeptide combined with a polypeptide adjuvant (human granulocyte-macrophage colony-stimulating factor). The primary endpoint is safety indicators, including general and specific adverse events which will be monitored continuously. Secondary endpoints are progression-free survival, objective response rate, objective duration of remission, 1-year survival rate and overall survival.

ETHICS AND DISSEMINATION

This study has received approval from the Ethics Committee of Chongqing University Cancer Hospital on 21 November 2019 (207/2019). The findings of this trial will be disseminated through national and international presentations and peer-reviewed publications.

TRIAL REGISTRATION NUMBER

ChiCTR1900025364.

Fueling Cancer Vaccines to Improve T Cell-Mediated Antitumor Immunity

Cancer vaccines offer the potential to enhance T cell-mediated antitumor immunity by expanding and increasing the function of tumor-specific T cells and shaping the recall response against recurring tumors. While the use of cancer vaccines is not a new immunotherapeutic approach, the cancer vaccine field continues to evolve as new antigen types emerge and vaccine formulations and delivery strategies are developed. As monotherapies, cancer vaccines have not been very efficacious in part due to pre-existing peripheral- and tumor-mediated tolerance mechanisms that limit T cell function. Over the years, various agents including Toll-like receptor agonists, cytokines, and checkpoint inhibitors have been employed as vaccine adjuvants and immune modulators to increase antigen-mediated activation, expansion, memory formation, and T effector cell function. A renewed interest in this approach has emerged as better neoepitope discovery tools are being developed and our understanding of what constitutes an effective cancer vaccine is improved. In the coming years, cancer vaccines will likely be vital to enhance the response to current immunotherapies. In this review, we discuss the various types of therapeutic cancer vaccines, including types of antigens and approaches used to enhance cancer vaccine responses such as TLR agonists, recombinant interleukin-2 and interleukin-2 derivatives, and checkpoint inhibitors.

Surgical Tumor-Derived Photothermal Nanovaccine for Personalized Cancer Therapy and Prevention

Recent breakthroughs in cell membrane-fabricated nanovaccine offer innovateive therapeutic options for preventing tumor metastasies and recurrence, yet the treatment of patient-specific solid tumor remained challenging owing to the immunosuppressive tumor microenvironment. Herein, we developed a personalized photothermal nanovaccine based on the surgical tumor-derived cell membranes (CMs) coating resiquimod (R848) loaded mesoporous polydopamine (MPDA) nanoparticles for targeting tumor photothermal immunotherapy and prevention. The fabricated photothermal nanovaccine MPDA-R848@CM (MR@C) demonstrates outstanding imaging-guided photothermal immunotherapy efficacy to eradicate solid tumors under near-IR laser irradiation and further inhibiting metastasis tumors by the resulted antitumor immunities, especially in combination with programmed death-ligand 1 antibody therapy (aPD-L1). Furthermore, from in vivo prophylactic testing results, it is confirmed that the 4T1 cells rechallenge can be prevented 100% in postsurgical tumor model after vaccination of the photothermal nanovaccine. Our work fabricates a personalized photothermal nanovaccine that possesses great potential for tumor-specific treatment and for preventing postoperative tumor recurrence.

Aluminum nanoparticles deliver a dual-epitope peptide for enhanced anti-tumor immunotherapy

Tumor peptide vaccines contain only key amino acid sequences of tumor neoantigens, and therefore can provide precise activation of immune responses. Recent research has found that short peptide vaccines restricted to MHC-I epitopes are insufficient to activate effective CD8⁺ T cell responses for tumor elimination, and assistance from CD4⁺ T cell immunity could significantly improve the therapeutic outcome. Herein, we proposed an innovative peptide vaccine strategy to simultaneously activate CD8⁺ and CD4⁺ T cell responses by combining MHC-I and MHC-II epitopes into one long peptide antigen. To further strengthen the anti-tumor immune response induced by this dual-epitope peptide, we engineered a PEG derivative (PpASE) stabilized aluminum nanoparticle for delivering the synthetic long peptides (ANLs). The synthesized nanovaccine with a diameter of ~100 nm showed good stability and enhanced antigen uptake by antigen-presenting cells (APCs). As a result, ANLs promoted the presentation of MHC-I epitope in APCs and induced stronger activation and proliferation of CD8⁺ T cells as compared to aluminum nanoparticle loaded with MHC-I epitope restricted peptides (ANSs). After subcutaneous vaccination, the developed nanovaccine significantly inhibited tumor growth and prolonged mouse survival in both B16-OVA and B16F10 tumor models. Finally, ANLs were also able to elevate the maturation level of human dendritic cells (DCs), showing a great possibility of clinical translation.

Cytotoxic T-Cell-Based Vaccine against SARS-CoV-2: A Hybrid Immunoinformatic Approach

This paper presents an alternative vaccination platform that provides long-term cellular immune protection mediated by cytotoxic T-cells. The immune response via cellular immunity creates superior resistance to viral mutations, which are currently the greatest threat to the global vaccination campaign. Furthermore, we also propose a safer, more facile, and physiologically appropriate immunization method using either intranasal or oral administration. The underlying technology is an adaptation of synthetic long peptides (SLPs) previously used in cancer immunotherapy. The overall quality of the SLP constructs was validated using in silico methods. SLPs comprising HLA class I and class II epitopes were designed to stimulate antigen cross-presentation and canonical class II presentation by dendritic cells. The desired effect is a cytotoxic T cell-mediated prompt and specific immune response against the virus-infected epithelia and a rapid and robust virus clearance. Epitopes isolated from COVID-19 convalescent patients were screened for HLA class I and class II binding (NetMHCpan and NetMHCIIpan) and highest HLA population coverage (IEDB Population Coverage). 15 class I and 4 class II epitopes were identified and used for this SLP design. The constructs were characterized based on their toxicity (ToxinPred), allergenicity (AllerCatPro), immunogenicity (VaxiJen 2.0), and physico-chemical parameters (ProtParam). Based on in silico predictions, out of 60 possible SLPs, 36 candidate structures presented a high probability to be immunogenic, non-allergenic, non-toxic, and stable. 3D peptide folding followed by 3D structure validation (PROCHECK) and molecular docking studies (HADDOCK 2.4) with Toll-like receptors 2 and 4 provided positive results, suggestive for favorable antigen presentation and immune stimulation.

Personalized therapy with peptide-based neoantigen vaccine (EVX-01) including a novel adjuvant, CAF®09b, in patients with metastatic melanoma

The majority of neoantigens arise from unique mutations that are not shared between individual patients, making neoantigen-directed immunotherapy a fully personalized treatment approach. Novel technical advances in next-generation sequencing of tumor samples and artificial intelligence (AI) allow fast and systematic prediction of tumor neoantigens. This study investigates feasibility, safety, immunity, and anti-tumor potential of the personalized peptide-based neoantigen vaccine, EVX-01, including the novel CD8⁺ T-cell inducing adjuvant, CAF®09b, in patients with metastatic melanoma (NTC03715985). The AI platform PIONEER^TM was used for identification of tumor-derived neoantigens to be included in a peptide-based personalized therapeutic cancer vaccine. EVX-01 immunotherapy consisted of 6 administrations with 5–10 PIONEER^TM-predicted neoantigens as synthetic peptides combined with the novel liposome-based Cationic Adjuvant Formulation 09b (CAF®09b) to strengthen T-cell responses. EVX-01 was combined with immune checkpoint inhibitors to augment the activity of EVX-01-induced immune responses. The primary endpoint was safety, exploratory endpoints included feasibility, immunologic and objective responses. This interim analysis reports the results from the first dose-level cohort of five patients. We documented a short vaccine manufacturing time of 48–55 days which enabled the initiation of EVX-01 treatment within 60 days from baseline biopsy. No severe adverse events were observed. EVX-01 elicited long-lasting EVX-01-specific T-cell responses in all patients. Competitive manufacturing time was demonstrated. EVX-01 was shown to be safe and able to elicit immune responses targeting tumor neoantigens with encouraging early indications of a clinical and meaningful antitumor efficacy, warranting further study.

Bedside formulation of a personalized multi-neoantigen vaccine against mammary carcinoma

Background

Harnessing the immune system to purposely recognize and destroy tumors represents a significant breakthrough in clinical oncology. Non-synonymous mutations (neoantigenic peptides) were identified as powerful cancer targets. This knowledge can be exploited for further improvements of active immunotherapies, including cancer vaccines, as T cells specific for neoantigens are not attenuated by immune tolerance mechanism and do not harm healthy tissues. The current study aimed at developing an optimized multitarget vaccine using short or long neoantigenic peptides utilizing virus-like particles (VLPs) as an efficient vaccine platform.

Methods

Mutations of murine mammary carcinoma cells were identified by integrating mass spectrometry-based immunopeptidomics and whole exome sequencing. Neoantigenic peptides were synthesized and covalently linked to virus-like nanoparticles using a Cu-free click chemistry method for easy preparation of vaccines against mouse mammary carcinoma.

Results

As compared with short peptides, vaccination with long peptides was superior in the generation of neoantigen-specific CD4⁺ and CD8⁺ T cells, which readily produced interferon gamma (IFN-γ) and tumor-necrosis factor α (TNF-α). The resulting anti-tumor effect was associated with favorable immune re-polarization in the tumor microenvironment through reduction of myeloid-derived suppressor cells. Vaccination with long neoantigenic peptides also decreased post-surgical tumor recurrence and metastases, and prolonged mouse survival, despite the tumor’s low mutational burden.

Conclusion

Integrating mass spectrometry-based immunopeptidomics and whole exome sequencing is an efficient approach for identifying neoantigenic peptides. Our multitarget VLP-based vaccine shows a promising anti-tumor effect in an aggressive murine mammary carcinoma model. Future clinical application using this strategy is readily feasible and practical, as click chemistry coupling of personalized synthetic peptides to the nanoparticles can be done at the bedside directly before injection.

Head and Neck Squamous Cell Carcinoma: Risk Factors, Molecular Alterations, Immunology and Peptide Vaccines

Head and neck squamous cell carcinoma (HNSCC) arises from the epithelial lining of the oral cavity, hypopharynx, oropharynx, and larynx. There are several potential risk factors that cause the generation of HNSCC, including cigarette smoking, alcohol consumption, betel quid chewing, inadequate nutrition, poor oral hygiene, HPV and Epstein–Barr virus, and Candida albicans infections. HNSCC has causative links to both environmental factors and genetic mutations, with the latter playing a more critical role in cancer progression. These molecular changes to epithelial cells include the inactivation of cancer suppressor genes and proto-oncogenes overexpression, resulting in tumour cell proliferation and distant metastasis. HNSCC patients have impaired dendritic cell (DC) and natural killer (NK) cell functions, increased production of higher immune-suppressive molecules, loss of regulatory T cells and co-stimulatory molecules and major histocompatibility complex (MHC) class Ι molecules, lower number of lymphocyte subsets, and a poor response to antigen-presenting cells. At present, the standard treatment modalities for HNSCC patients include surgery, chemotherapy and radiotherapy, and combinatorial therapy. Despite advances in the development of novel treatment modalities over the last few decades, survival rates of HNSCC patients have not increased. To establish effective immunotherapies, a greater understanding of interactions between the immune system and HNSCC is required, and there is a particular need to develop novel therapeutic options. A therapeutic cancer vaccine has been proposed as a promising method to improve outcome by inducing a powerful adaptive immune response that leads to cancer cell elimination. Compared with other vaccines, peptide cancer vaccines are more robust and specific. In the past few years, there have been remarkable achievements in peptide-based vaccines for HNSCC patients. Here, we summarize the latest molecular alterations in HNSCC, explore the immune response to HNSCC, and discuss the latest developments in peptide-based cancer vaccine strategies. This review highlights areas for valuable future research focusing on peptide-based cancer vaccines.

Tumor Antigen-Based Nanovaccines for Cancer Immunotherapy: A Review

As an important means of tumor immunotherapy, tumor vaccines have achieved exciting results in the past few decades. However, there are still many obstacles that hinder tumor vaccines from achieving maximum efficacy, including lack of tumor antigens, low antigen immunogenicity and poor delivery efficiency. To overcome these challenges, researchers have developed and investigated various new types of tumor antigens with higher antigenic specificity and broader antigen spectrum, such as tumor-specific peptide antigens, tumor lysates, tumor cell membrane, tumor associated exosomes, etc. At the same time, different nanoparticulate delivery platforms have been developed to increase the immunogenicity of the tumor antigens, for example by increasing their targeting efficiency of antigen-presenting cells and lymph nodes, and by co-delivering antigens with adjuvants. In this review, we summarized different types of the tumor antigens that have been reported, and introduced several nanovaccine strategies for increasing the immunogenicity of tumor antigens. The review of recent progress in these fields may provide reference for the follow-up studies of tumor antigen-based cancer immunotherapy.

Nanobiotechnology-assisted therapies to manage brain cancer in personalized manner

There are numerous investigated factors that limit brain cancer treatment efficacy such as ability of prescribed therapy to cross the blood-brain barrier (BBB), tumor specific delivery of a therapeutics, transport within brain interstitium, and resistance of tumor cells against therapies. Recent breakthroughs in the field of nano-biotechnology associated with developing multifunctional nano-theranostic emerged as an effective way to manage brain cancer in terms of higher efficacy and least possible adverse effects. Keeping challenges and state-of-art accomplishments into consideration, this review proposes a comprehensive, careful, and critical discussion focused on efficient nano-enabled platforms including nanocarriers for drug delivery across the BBB and nano-assisted therapies (e.g., nano-immunotherapy, nano-stem cell therapy, and nano-gene therapy) investigated for brain cancer treatment. Besides therapeutic efficacy point-of-view, efforts are being made to explore ways projected to tune such developed nano-therapeutic for treating patients in personalized manner via controlling size, drug loading, delivery, and retention. Personalized brain tumor management based on advanced nano-therapies can potentially lead to excellent therapeutic benefits based on unique genetic signatures in patients and their individual disease profile. Moreover, applicability of nano-systems as stimulants to manage the brain cancer growth factors has also been discussed in photodynamic therapy and radiotherapy. Overall, this review offers a comprehensive information on emerging opportunities in nanotechnology for advancing the brain cancer treatment.

Enhancing therapeutic performance of personalized cancer vaccine via delivery vectors

In recent years, personalized cancer vaccines have gained increasing attention as emerging immunotherapies with the capability to overcome interindividual differences and show great benefits for individual patients in the clinic due to the highly tailored vaccine formulations. A large number of materials have been studied as delivery vectors to enhance the therapeutic performance of personalized cancer vaccines, including artificial materials, engineered microorganisms, cells and cell derivatives. These delivery vectors with distinct features are employed to change antigen biodistributions and to facilitate antigen uptake, processing and presentation, improving the strength, velocity, and duration of the immune response when delivered by different strategies. Here, we provide an overview of personalized cancer vaccine delivery vectors, describing their materials, physicochemical properties, delivery strategies and challenges for clinical transformation.

The Role of Neoantigens in Cancer Immunotherapy

Somatic mutation-derived neoantigens, expressed only on tumor cells, may elicit antitumor T-cell responses in cancer immunotherapies with minimal immune tolerance. Neoantigens can be identified by multiple bioinformatics technologies, mainly based on whole-exome sequencing. Personalized cancer vaccines and adoptive T cell therapies are two primary treatment modalities targeting neoantigens, and both of them have shown promising therapeutic effects. This review, summarizes the history of neoantigen-related tumor control, introduces recent neoantigen screening and identification methods, and discusses the role of neoantigen in cancer immunotherapies. Moreover, we propose the challenges of targeting neoantigens for cancer treatment.

Targeting neoantigens for cancer immunotherapy

Neoantigens, a type of tumor-specific antigens derived from non-synonymous mutations, have recently been characterized as attractive targets for cancer immunotherapy. Owing to the development of next-generation sequencing and utilization of machine-learning algorithms, it has become feasible to computationally predict neoantigens by depicting genetic alterations, aberrant post-transcriptional mRNA processing and abnormal mRNA translation events within tumor tissues. Consequently, neoantigen-based therapies such as cancer vaccines have been widely tested in clinical trials and have demonstrated promising safety and efficacy, opening a new era for cancer immunotherapy. We systematically summarize recent advances in the identification of both personalized and public neoantigens, neoantigen formulations and neoantigen-based clinical trials in this review. Moreover, we discuss future techniques and strategies for neoantigen-based cancer treatment either as a monotherapy or as a combination therapy with radiotherapy, chemotherapy or immune checkpoint inhibitors.

The Evolution of Cancer Immunotherapy

Immunotherapy has changed the environment of cancer treatment by providing new and efficacious therapy options for many solid and hematologic malignancies. Although not a new field of oncology, immunotherapy has quickly developed into one of the most flourishing fields in medicine. In this review article, we explore key discoveries which helped to shape our current understanding of the immune system’s role in neoplasms. Many landmark developments include the advancements in checkpoint inhibitors, monoclonal antibodies, CAR-T cells and anti-cancer vaccines. We also explore the drawbacks and efficacy of various categories of immunotherapy. Ongoing investigations within immunotherapy, such as the gut microbiome, combining checkpoint inhibitors and gene sequencing, continue to personalize treatments for cancer patients, providing exciting and endless possibilities for the future.

Neoantigen landscape in metastatic nasopharyngeal carcinoma

Background: Reportedly, nasopharyngeal carcinoma (NPC) patients with MHC I Class aberration are prone to poor survival outcomes, which indicates that the deficiency of tumor neoantigens might represent a mechanism of immune surveillance escape in NPC.

Methods: To clearly delineate the landscape of neoantigens in NPC, we performed DNA and RNA sequencing on paired primary tumor, regional lymph node metastasis and distant metastasis samples from 26 patients. Neoantigens were predicted using pVACseq pipeline. Subtype prediction model was built using random forest algorithm.

Results: Portraying the landscape of neoantigens in NPC for the first time, we found that the neoantigen load of NPC was above average compared to that of other cancers in The Cancer Genome Atlas program. While the quantity and quality of neoantigens were similar among primary tumor, regional lymph node metastasis and distant metastasis samples, neoantigen depletion was more severe in metastatic sites than in primary tumors. Upon tracking the clonality change of neoantigens, we found that neoantigen reduction occurred during metastasis. Building a subtype prediction model based on reported data, we observed that subtype I lacked T cells and suffered from severe neoantigen depletion, subtype II highly expressed immune checkpoint molecules and suffered from the least neoantigen depletion, and subtype III was heterogenous.

Conclusions: These results indicate that neoantigens are conducive to the guidance of clinical treatment, and personalized therapeutic vaccines for NPC deserve deeper basic and clinical investigations to make them feasible in the future.

Trends in peptide drug discovery

Since the introduction of insulin almost a century ago, more than 80 peptide drugs have reached the market for a wide range of diseases, including diabetes, cancer, osteoporosis, multiple sclerosis, HIV infection and chronic pain. In this Perspective, we summarize key trends in peptide drug discovery and development, covering the early efforts focused on human hormones, elegant medicinal chemistry and rational design strategies, peptide drugs derived from nature, and major breakthroughs in molecular biology and peptide chemistry that continue to advance the field. We emphasize lessons from earlier approaches that are still relevant today as well as emerging strategies such as integrated venomics and peptide-display libraries that create new avenues for peptide drug discovery. We also discuss the pharmaceutical landscape in which peptide drugs could be particularly valuable and analyse the challenges that need to be addressed for them to reach their full potential.

mRNA vaccine for cancer immunotherapy

mRNA vaccines have become a promising platform for cancer immunotherapy. During vaccination, naked or vehicle loaded mRNA vaccines efficiently express tumor antigens in antigen-presenting cells (APCs), facilitate APC activation and innate/adaptive immune stimulation. mRNA cancer vaccine precedes other conventional vaccine platforms due to high potency, safe administration, rapid development potentials, and cost-effective manufacturing. However, mRNA vaccine applications have been limited by instability, innate immunogenicity, and inefficient in vivo delivery. Appropriate mRNA structure modifications (i.e., codon optimizations, nucleotide modifications, self-amplifying mRNAs, etc.) and formulation methods (i.e., lipid nanoparticles (LNPs), polymers, peptides, etc.) have been investigated to overcome these issues. Tuning the administration routes and co-delivery of multiple mRNA vaccines with other immunotherapeutic agents (e.g., checkpoint inhibitors) have further boosted the host anti-tumor immunity and increased the likelihood of tumor cell eradication. With the recent U.S. Food and Drug Administration (FDA) approvals of LNP-loaded mRNA vaccines for the prevention of COVID-19 and the promising therapeutic outcomes of mRNA cancer vaccines achieved in several clinical trials against multiple aggressive solid tumors, we envision the rapid advancing of mRNA vaccines for cancer immunotherapy in the near future. This review provides a detailed overview of the recent progress and existing challenges of mRNA cancer vaccines and future considerations of applying mRNA vaccine for cancer immunotherapies.

Cancer Vaccines: Antigen Selection Strategy

Unlike traditional cancer therapies, cancer vaccines (CVs) harness a high specificity of the host’s immunity to kill tumor cells. CVs can train and bolster the patient’s immune system to recognize and eliminate malignant cells by enhancing immune cells’ identification of antigens expressed on cancer cells. Various features of antigens like immunogenicity and avidity influence the efficacy of CVs. Therefore, the choice and application of antigens play a critical role in establishing and developing CVs. Tumor-associated antigens (TAAs), a group of proteins expressed at elevated levels in tumor cells but lower levels in healthy normal cells, have been well-studied and developed in CVs. However, immunological tolerance, HLA restriction, and adverse events are major obstacles that threaten TAA-based CVs’ efficacy due to the “self-protein” characteristic of TAAs. As “abnormal proteins” that are completely absent from normal cells, tumor-specific antigens (TSAs) can trigger a robust immune response against tumor cells with high specificity and without going through central tolerance, contributing to cancer vaccine development feasibility. In this review, we focus on the unique features of TAAs and TSAs and their application in vaccines, summarizing their performance in preclinical and clinical trials.