A novel, disruptive vaccination technology: self-adjuvanted RNActive(®) vaccines

Tailoring mRNA Vaccine to Balance Innate/Adaptive Immune Response

mRNA vaccine platforms present numerous advantages, such as versatility, rapid production, and induction of cellular and humoral responses. Moreover, mRNAs have inherent adjuvant properties due to their complex interaction with pattern recognition receptors (PRRs). This recognition can be either beneficial in activating antigen-presenting cells (APCs) or detrimental by indirectly blocking mRNA translation. To decipher this Janus effect, we describe the different innate response mechanisms triggered by mRNA molecules and how each element from the 5' cap to the poly-A tail interferes with innate/adaptive immune responses. Then, we emphasize the importance of some critical steps such as production, purification, and formulation as key events to further improve the quality of immune responses and balance innate and adaptive immunity.

The challenge and prospect of mRNA therapeutics landscape

Messenger RNA (mRNA)-based therapeutics hold the potential to cause a major revolution in the pharmaceutical industry because they can be used for precise and individualized therapy, and enable patients to produce therapeutic proteins in their own bodies without struggling with the comprehensive manufacturing issues associated with recombinant proteins. Compared with the current therapeutics, the production of mRNA is much cost-effective, faster and more flexible because it can be easily produced by in vitro transcription, and the process is independent of mRNA sequence. Moreover, mRNA vaccines allow people to develop personalized medications based on sequencing results and/or personalized conditions rapidly. Along with the great potential from bench to bedside, technical obstacles facing mRNA pharmaceuticals are also obvious. The stability, immunogenicity, translation efficiency, and delivery are all pivotal issues need to be addressed. In the recently published research results, these issues are gradually being overcome by state-of-the-art development technologies. In this review, we describe the structural properties and modification technologies of mRNA, summarize the latest advances in developing mRNA delivery systems, review the preclinical and clinical applications, and put forward our views on the prospect and challenges of developing mRNA into a new class of drug.

Broadly Protective Strategies Against Influenza Viruses: Universal Vaccines and Therapeutics

Influenza virus is a respiratory pathogen that can cause disease in humans, with symptoms ranging from mild to life-threatening. The vast majority of influenza virus infections in humans are observed during seasonal epidemics and occasional pandemics. Given the substantial public health burden associated with influenza virus infection, yearly vaccination is recommended for protection against seasonal influenza viruses. Despite vigilant surveillance for new variants and careful selection of seasonal vaccine strains, the efficacy of seasonal vaccines can vary widely from year to year. This often results in lowered protection within the population, regardless of vaccination status. In order to broaden the protection afforded by seasonal influenza vaccines, the National Institute of Allergy and Infectious Diseases (NIAID) has deemed the development of a universal influenza virus vaccine to be a priority in influenza virus vaccine research. This universal vaccine would provide protection against all influenza virus strains, eliminating the need for the yearly reformulations of seasonal influenza vaccines. In addition to universal influenza vaccine efforts, substantial progress has been made in developing novel influenza virus therapeutics that utilize broadly neutralizing antibodies to provide protection against influenza virus infection and to mitigate disease outcomes during infection. In this review, we discuss various approaches toward the goal of improving influenza virus vaccine efficacy through a universal influenza virus vaccine. We also address the novel methods of discovery and utilization of broadly neutralizing antibodies to improve influenza disease outcomes.

The promise of mRNA vaccines: a biotech and industrial perspective

mRNA technologies have the potential to transform areas of medicine, including the prophylaxis of infectious diseases. The advantages for vaccines range from the acceleration of immunogen discovery to rapid response and multiple disease target manufacturing. A greater understanding of quality attributes that dictate translation efficiency, as well as a comprehensive appreciation of the importance of mRNA delivery, are influencing a new era of investment in development activities. The application of translational sciences and growing early-phase clinical experience continue to inform candidate vaccine selection. Here we review the state of the art for the prevention of infectious diseases by using mRNA and pertinent topics to the biotechnology and pharmaceutical industries.

Comprehensive Analysis of the Safety Profile of a Single-Stranded RNA Nano-Structure Adjuvant

Adjuvants enhance the efficacy of vaccines by stimulating immune response-related gene expression and pathways. Although some adjuvants have been approved for commercial use in human vaccines (e.g., Alum, MF59, and AS03), they might elicit adverse side effects, such as autoimmune diseases. Recently, we developed a novel single-stranded RNA (ssRNA) nano-structure adjuvant, which can stimulate both Th1 and Th2 responses. In this study, we evaluated the safety and toxicological profiles of this ssRNA nano-structure adjuvant in vitro and in vivo. Mice were intramuscularly immunized with the ssRNA nano-structure adjuvant three times, once every 2 weeks. The results indicate no significant differences in hematological and serum biochemistry parameters between the ssRNA-treated groups and the control group. From a histopathological perspective, no evidence of tissue damage was found in any group. The levels of IgE and anti-nuclear antibodies, which are markers of autoimmune disease, were not different between the ssRNA-treated groups and the control group. The findings of this study suggest that the ssRNA nano-structure can be used as a safe adjuvant to increase vaccine efficacies.

Inside out: optimization of lipid nanoparticle formulations for exterior complexation and in vivo delivery of saRNA

Self-amplifying RNA (saRNA) is a promising biotherapeutic tool that has been used as a vaccine against both infectious diseases and cancer. saRNA has been shown to induce protein expression for up to 60 days and elicit immune responses with lower dosing than messenger RNA (mRNA). Because saRNA is a large (~9500 nt), negatively charged molecule, it requires a delivery vehicle for efficient cellular uptake and degradation protection. Lipid nanoparticles (LNPs) have been widely used for RNA formulations, where the prevailing paradigm is to encapsulate RNA within the particle, including the first FDA-approved small-interfering siRNA therapy. Here, we compared LNP formulations with cationic and ionizable lipids with saRNA either on the interior or exterior of the particle. We show that LNPs formulated with cationic lipids protect saRNA from RNAse degradation, even when it is adsorbed to the surface. Furthermore, cationic LNPs deliver saRNA equivalently to particles formulated with saRNA encapsulated in an ionizable lipid particle, both in vitro and in vivo. Finally, we show that cationic and ionizable LNP formulations induce equivalent antibodies against HIV-1 Env gp140 as a model antigen. These studies establish formulating saRNA on the surface of cationic LNPs as an alternative to the paradigm of encapsulating RNA.

Co-administration of GM-CSF expressing RNA is a powerful tool to enhance potency of SAM-based vaccines

Self-amplifying mRNAs (SAM)-based vaccines have been shown to induce a robust immune response in various animal species against both viral and bacterial pathogens. Due to their synthetic nature and to the versatility of the manufacturing process, SAM technology may represent an attractive solution for rapidly producing novel vaccines, which is particularly critical in case of pandemic infections or diseases mediated by newly emerging pathogens. Recent published data support the hypothesis that Antigen Presenting Cells (APCs) are responsible for CD8+ T-cell priming after SAM vaccination, suggesting cross-priming as the key mechanism for antigen presentation by SAM vaccines. In our study we investigated the possibility to enhance the immune response induced in mice by a single immunization with SAM by increasing the recruitment of APCs at the site of injection. To enhance SAM immunogenicity, we selected murine granulocyte-macrophage colony-stimulating factor (GM-CSF) as a model chemoattractant for APCs, and developed a SAM-GM-CSF vector. We evaluated whether the use of SAM-GM-CSF in combination with a SAM construct encoding the Influenza A virus nucleoprotein (NP) would lead to an increase of APC recruitment and NP-specific immune response. We indeed observed that the administration of SAM-GM-CSF enhances the recruitment of APCs at the injection site. Consistently with our hypothesis, co-administration of SAM-GM-CSF with SAM-NP significantly improved the magnitude of NP-specific CD8+ T-cell response both in terms of frequency of cytotoxic antigen-specific CD8+ T-cells and their functional activity in vivo. Furthermore, co-immunization with SAM-GM-CSF and SAM-NP provided an increase in protection against a lethal challenge with influenza virus. In conclusion, we demonstrated that increased recruitment of APCs at the site of injection is associated with an enhanced effectiveness of SAM vaccination and might be a powerful tool to potentiate the efficacy of RNA vaccination.

mRNA vaccines against H10N8 and H7N9 influenza viruses of pandemic potential are immunogenic and well tolerated in healthy adults in phase 1 randomized clinical trials

BACKGROUND

We evaluated safety and immunogenicity of the first mRNA vaccines against potentially pandemic avian H10N8 and H7N9 influenza viruses.

METHODS

Two randomized, placebo-controlled, double-blind, phase 1 clinical trials enrolled participants between December 2015 and August 2017 at single centers in Germany (H10N8) and USA (H7N9). Healthy adults (ages 18-64 years for H10N8 study; 18-49 years for H7N9 study) participated. Participants received vaccine or placebo in a 2-dose vaccination series 3 weeks apart. H10N8 intramuscular (IM) dose levels of 25, 50, 75, 100, and 400 µg and intradermal dose levels of 25 and 50 µg were evaluated. H7N9 IM 10-, 25-, and 50-µg dose levels were evaluated; 2-dose series 6 months apart was also evaluated. Primary endpoints were safety (adverse events) and tolerability. Secondary immunogenicity outcomes included humoral (hemagglutination inhibition [HAI], microneutralization [MN] assays) and cell-mediated responses (ELISPOT assay).

RESULTS

H10N8 and H7N9 mRNA IM vaccines demonstrated favorable safety and reactogenicity profiles. No vaccine-related serious adverse event was reported. For H10N8 (N = 201), 100-µg IM dose induced HAI titers ≥ 1:40 in 100% and MN titers ≥ 1:20 in 87.0% of participants. The 25-µg intradermal dose induced HAI titers > 1:40 in 64.7% of participants compared to 34.5% of participants receiving the IM dose. For H7N9 (N = 156), IM doses of 10, 25, and 50 µg achieved HAI titers ≥ 1:40 in 36.0%, 96.3%, and 89.7% of participants, respectively. MN titers ≥ 1:20 were achieved by 100% in the 10- and 25-µg groups and 96.6% in the 50-µg group. Seroconversion rates were 78.3% (HAI) and 87.0% (MN) for H10N8 (100 µg IM) and 96.3% (HAI) and 100% (MN) in H7N9 (50 µg). Significant cell-mediated responses were not detected in either study.

CONCLUSIONS

The first mRNA vaccines against H10N8 and H7N9 influenza viruses were well tolerated and elicited robust humoral immune responses. ClinicalTrials.gov NCT03076385 and NCT03345043.

Delivering the Messenger: Advances in Technologies for Therapeutic mRNA Delivery

mRNA has broad potential as a therapeutic. Current clinical efforts are focused on vaccination, protein replacement therapies, and treatment of genetic diseases. The clinical translation of mRNA therapeutics has been made possible through advances in the design of mRNA manufacturing and intracellular delivery methods. However, broad application of mRNA is still limited by the need for improved delivery systems. In this review, we discuss the challenges for clinical translation of mRNA-based therapeutics, with an emphasis on recent advances in biomaterials and delivery strategies, and we present an overview of the applications of mRNA-based delivery for protein therapy, gene editing, and vaccination.

Advances in mRNA Vaccines for Infectious Diseases

During the last two decades, there has been broad interest in RNA-based technologies for the development of prophylactic and therapeutic vaccines. Preclinical and clinical trials have shown that mRNA vaccines provide a safe and long-lasting immune response in animal models and humans. In this review, we summarize current research progress on mRNA vaccines, which have the potential to be quick-manufactured and to become powerful tools against infectious disease and we highlight the bright future of their design and applications.

Proximity Ligation Assays for In Situ Detection of Innate Immune Activation: Focus on In Vitro-Transcribed mRNA

The characterization of innate immune activation is crucial for vaccine and therapeutic development, including RNA-based vaccines, a promising approach. Current measurement methods quantify type I interferon and inflammatory cytokine production, but they do not allow for the isolation of individual pathways, do not provide kinetic activation or spatial information within tissues, and cannot be translated into clinical studies. Here we demonstrated the use of proximity ligation assays (PLAs) to detect pattern recognition receptor (PRR) activation in cells and in tissue samples. First, we validated PLA's sensitivity and specificity using well-characterized soluble agonists. Next, we characterized PRR activation from in vitro-transcribed (IVT) mRNAs, as well as the effect of sequence and base modifications in vitro. Finally, we established the measurement of PRR activation in tissue sections via PLA upon IVT mRNA intramuscular (i.m.) injection in mice. Overall, our results indicate that PLA is a valuable, versatile, and sensitive tool to monitor PRR activation for vaccine, adjuvant, and therapeutic screening.

Phase Ib evaluation of a self-adjuvanted protamine formulated mRNA-based active cancer immunotherapy, BI1361849 (CV9202), combined with local radiation treatment in patients with stage IV non-small cell lung cancer

BACKGROUND

Preclinical studies demonstrate synergism between cancer immunotherapy and local radiation, enhancing anti-tumor effects and promoting immune responses. BI1361849 (CV9202) is an active cancer immunotherapeutic comprising protamine-formulated, sequence-optimized mRNA encoding six non-small cell lung cancer (NSCLC)-associated antigens (NY-ESO-1, MAGE-C1, MAGE-C2, survivin, 5T4, and MUC-1), intended to induce targeted immune responses.

METHODS

We describe a phase Ib clinical trial evaluating treatment with BI1361849 combined with local radiation in 26 stage IV NSCLC patients with partial response (PR)/stable disease (SD) after standard first-line therapy. Patients were stratified into three strata (1: non-squamous NSCLC, no epidermal growth factor receptor (EGFR) mutation, PR/SD after ≥4 cycles of platinum- and pemetrexed-based treatment [n = 16]; 2: squamous NSCLC, PR/SD after ≥4 cycles of platinum-based and non-platinum compound treatment [n = 8]; 3: non-squamous NSCLC, EGFR mutation, PR/SD after ≥3 and ≤ 6 months EGFR-tyrosine kinase inhibitor (TKI) treatment [n = 2]). Patients received intradermal BI1361849, local radiation (4 × 5 Gy), then BI1361849 until disease progression. Strata 1 and 3 also had maintenance pemetrexed or continued EGFR-TKI therapy, respectively. The primary endpoint was evaluation of safety; secondary objectives included assessment of clinical efficacy (every 6 weeks during treatment) and of immune response (on Days 1 [baseline], 19 and 61).

RESULTS

Study treatment was well tolerated; injection site reactions and flu-like symptoms were the most common BI1361849-related adverse events. Three patients had grade 3 BI1361849-related adverse events (fatigue, pyrexia); there was one grade 3 radiation-related event (dysphagia). In comparison to baseline, immunomonitoring revealed increased BI1361849 antigen-specific immune responses in the majority of patients (84%), whereby antigen-specific antibody levels were increased in 80% and functional T cells in 40% of patients, and involvement of multiple antigen specificities was evident in 52% of patients. One patient had a partial response in combination with pemetrexed maintenance, and 46.2% achieved stable disease as best overall response. Best overall response was SD in 57.7% for target lesions.

CONCLUSION

The results support further investigation of mRNA-based immunotherapy in NSCLC including combinations with immune checkpoint inhibitors.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT01915524 .

mRNA as a Transformative Technology for Vaccine Development to Control Infectious Diseases

In the last two decades, there has been growing interest in mRNA-based technology for the development of prophylactic vaccines against infectious diseases. Technological advancements in RNA biology, chemistry, stability, and delivery systems have accelerated the development of fully synthetic mRNA vaccines. Potent, long-lasting, and safe immune responses observed in animal models, as well as encouraging data from early human clinical trials, make mRNA-based vaccination an attractive alternative to conventional vaccine approaches. Thanks to these data, together with the potential for generic, low-cost manufacturing processes and the completely synthetic nature, the prospects for mRNA vaccines are very promising. In addition, mRNA vaccines have the potential to streamline vaccine discovery and development, and facilitate a rapid response to emerging infectious diseases. In this review, we overview the unique attributes of mRNA vaccine approaches, review the data of mRNA vaccines against infectious diseases, discuss the current challenges, and highlight perspectives about the future of this promising technology.

New Vaccine Technologies to Combat Outbreak Situations

Ever since the development of the first vaccine more than 200 years ago, vaccinations have greatly decreased the burden of infectious diseases worldwide, famously leading to the eradication of small pox and allowing the restriction of diseases such as polio, tetanus, diphtheria, and measles. A multitude of research efforts focuses on the improvement of established and the discovery of new vaccines such as the HPV (human papilloma virus) vaccine in 2006. However, radical changes in the density, age distribution and traveling habits of the population worldwide as well as the changing climate favor the emergence of old and new pathogens that bear the risk of becoming pandemic threats. In recent years, the rapid spread of severe infections such as HIV, SARS, Ebola, and Zika have highlighted the dire need for global preparedness for pandemics, which necessitates the extremely rapid development and comprehensive distribution of vaccines against potentially previously unknown pathogens. What is more, the emergence of antibiotic resistant bacteria calls for new approaches to prevent infections. Given these changes, established methods for the identification of new vaccine candidates are no longer sufficient to ensure global protection. Hence, new vaccine technologies able to achieve rapid development as well as large scale production are of pivotal importance. This review will discuss viral vector and nucleic acid-based vaccines (DNA and mRNA vaccines) as new approaches that might be able to tackle these challenges to global health.

Current Challenges in Delivery and Cytosolic Translocation of Therapeutic RNAs

RNA interference (RNAi) is a fundamental cellular process for the posttranscriptional regulation of gene expression. RNAi can exogenously be modulated by small RNA oligonucleotides, such as microRNAs (miRNAs) and small interfering RNAs (siRNAs), or by antisense oligonucleotides. These small oligonucleotides provided the scientific community with powerful and versatile tools to turn off the expression of genes of interest, and hold out the promise of new therapeutic solutions against a wide range of gene-associated pathologies. However, unmodified nucleic acids are highly instable in biological systems, and their weak interaction with plasma proteins confers an unfavorable pharmacokinetics. In this review, we first provide an overview of the most efficient chemical strategies that, over the past 30 years, have been used to significantly improve the therapeutic potential of oligonucleotides. Oligonucleotides targeting and delivery technologies are then presented, including covalent conjugates between oligonucleotides and targeting ligand, and noncovalent association with lipid or polymer nanoparticles. Finally, we specifically focus on the endosomal escape step, which represents a major stumbling block for the effective use of oligonucleotides as therapeutic agents. The need for approaches to quantitatively measure endosomal escape and cytosolic arrival of biomolecules is discussed in the context of the development of efficient oligonucleotide targeting and delivery vectors.

Nucleoside-modified mRNA vaccines induce potent T follicular helper and germinal center B cell responses

T follicular helper (Tfh) cells are required to develop germinal center (GC) responses and drive immunoglobulin class switch, affinity maturation, and long-term B cell memory. In this study, we characterize a recently developed vaccine platform, nucleoside-modified, purified mRNA encapsulated in lipid nanoparticles (mRNA-LNPs), that induces high levels of Tfh and GC B cells. Intradermal vaccination with nucleoside-modified mRNA-LNPs encoding various viral surface antigens elicited polyfunctional, antigen-specific, CD4⁺ T cell responses and potent neutralizing antibody responses in mice and nonhuman primates. Importantly, the strong antigen-specific Tfh cell response and high numbers of GC B cells and plasma cells were associated with long-lived and high-affinity neutralizing antibodies and durable protection. Comparative studies demonstrated that nucleoside-modified mRNA-LNP vaccines outperformed adjuvanted protein and inactivated virus vaccines and pathogen infection. The incorporation of noninflammatory, modified nucleosides in the mRNA is required for the production of large amounts of antigen and for robust immune responses.

New Kids on the Block: RNA-Based Influenza Virus Vaccines

RNA-based immunization strategies have emerged as promising alternatives to conventional vaccine approaches. A substantial body of published work demonstrates that RNA vaccines can elicit potent, protective immune responses against various pathogens. Consonant with its huge impact on public health, influenza virus is one of the best studied targets of RNA vaccine research. Currently licensed influenza vaccines show variable levels of protection against seasonal influenza virus strains but are inadequate against drifted and pandemic viruses. In recent years, several types of RNA vaccines demonstrated efficacy against influenza virus infections in preclinical models. Additionally, comparative studies demonstrated the superiority of some RNA vaccines over the currently used inactivated influenza virus vaccines in animal models. Based on these promising preclinical results, clinical trials have been initiated and should provide valuable information about the translatability of the impressive preclinical data to humans. This review briefly describes RNA-based vaccination strategies, summarizes published preclinical and clinical data, highlights the roadblocks that need to be overcome for clinical applications, discusses the landscape of industrial development, and shares the authors' personal perspectives about the future of RNA-based influenza virus vaccines.

Assessing the Importance of Domestic Vaccine Manufacturing Centers: An Overview of Immunization Programs, Vaccine Manufacture, and Distribution

Vaccines have significantly reduced the detrimental effects of numerous human infectious diseases worldwide, helped to reduce drastically child mortality rates and even achieved eradication of major pathogens, such as smallpox. These achievements have been possible due to a dedicated effort for vaccine research and development, as well as an effective transfer of these vaccines to public health care systems globally. Either public or private institutions have committed to developing and manufacturing vaccines for local or international population supply. However, current vaccine manufacturers worldwide might not be able to guarantee sufficient vaccine supplies for all nations when epidemics or pandemics events could take place. Currently, different countries produce their own vaccine supplies under Good Manufacturing Practices, which include the USA, Canada, China, India, some nations in Europe and South America, such as Germany, the Netherlands, Italy, France, Argentina, and Brazil, respectively. Here, we discuss some of the vaccine programs and manufacturing capacities, comparing the current models of vaccine management between industrialized and developing countries. Because local vaccine production undoubtedly provides significant benefits for the respective population, the manufacture capacity of these prophylactic products should be included in every country as a matter of national safety.

mRNA vaccines - a new era in vaccinology

mRNA vaccines represent a promising alternative to conventional vaccine approaches because of their high potency, capacity for rapid development and potential for low-cost manufacture and safe administration. However, their application has until recently been restricted by the instability and inefficient in vivo delivery of mRNA. Recent technological advances have now largely overcome these issues, and multiple mRNA vaccine platforms against infectious diseases and several types of cancer have demonstrated encouraging results in both animal models and humans. This Review provides a detailed overview of mRNA vaccines and considers future directions and challenges in advancing this promising vaccine platform to widespread therapeutic use.

RNActive® Technology: Generation and Testing of Stable and Immunogenic mRNA Vaccines

Developing effective mRNA vaccines poses certain challenges concerning mRNA stability and ability to induce sufficient immune stimulation and requires a specific panel of techniques for production and testing. Here, we describe the production of stabilized mRNA with enhanced immunogenicity, generated using conventional nucleotides only, by introducing changes to the mRNA sequence and by complexation with the nucleotide-binding peptide protamine (RNActive® technology). Methods described here include the synthesis, purification, and protamine complexation of mRNA vaccines as well as a comprehensive panel of in vitro and in vivo methods for evaluation of vaccine quality and immunogenicity.

Unmodified mRNA in LNPs constitutes a competitive technology for prophylactic vaccines

mRNA represents a promising new vaccine technology platform with high flexibility in regard to development and production. Here, we demonstrate that vaccines based on sequence optimized, chemically unmodified mRNA formulated in optimized lipid nanoparticles (LNPs) are highly immunogenic and well tolerated in non-human primates (NHPs). Single intramuscular vaccination of NHPs with LNP-formulated mRNAs encoding rabies or influenza antigens induced protective antibody titers, which could be boosted and remained stable during an observation period of up to 1 year. First mechanistic insights into the mode of action of the LNP-formulated mRNA vaccines demonstrated a strong activation of the innate immune response at the injection site and in the draining lymph nodes (dLNs). Activation of the innate immune system was reflected by a transient induction of pro-inflammatory cytokines and chemokines and activation of the majority of immune cells in the dLNs. Notably, our data demonstrate that mRNA vaccines can compete with licensed vaccines based on inactivated virus or are even superior in respect of functional antibody and T cell responses. Importantly, we show that the developed LNP-formulated mRNA vaccines can be used as a vaccination platform allowing multiple, sequential vaccinations against different pathogens. These results provide strong evidence that the mRNA technology is a valid approach for the development of effective prophylactic vaccines to prevent infectious diseases.

Efficient Targeting and Activation of Antigen-Presenting Cells In Vivo after Modified mRNA Vaccine Administration in Rhesus Macaques

mRNA vaccines are rapidly emerging as a powerful platform for infectious diseases because they are well tolerated, immunogenic, and scalable and are built on precise but adaptable antigen design. We show that two immunizations of modified non-replicating mRNA encoding influenza H10 hemagglutinin (HA) and encapsulated in lipid nanoparticles (LNP) induce protective HA inhibition titers and H10-specific CD4⁺ T cell responses after intramuscular or intradermal delivery in rhesus macaques. Administration of LNP/mRNA induced rapid and local infiltration of neutrophils, monocytes, and dendritic cells (DCs) to the site of administration and the draining lymph nodes (LNs). While these cells efficiently internalized LNP, mainly monocytes and DCs translated the mRNA and upregulated key co-stimulatory receptors (CD80 and CD86). This coincided with upregulation of type I IFN-inducible genes, including MX1 and CXCL10. The innate immune activation was transient and resulted in priming of H10-specific CD4⁺ T cells exclusively in the vaccine-draining LNs. Collectively, this demonstrates that mRNA-based vaccines induce type-I IFN-polarized innate immunity and, when combined with antigen production by antigen-presenting cells, lead to generation of potent vaccine-specific responses.

Mechanism of action of mRNA-based vaccines

INTRODUCTION

The present review summarizes the growing body of work defining the mechanisms of action of this exciting new vaccine technology that should allow rational approaches in the design of next generation mRNA vaccines. Areas covered: Bio-distribution of mRNA, localization of antigen production, role of the innate immunity, priming of the adaptive immune response, route of administration and effects of mRNA delivery systems. Expert commentary: In the last few years, the development of RNA vaccines had a fast growth, the rising number of proof will enable rational approaches to improving the effectiveness and safety of this modern class of medicine.

CRISPR/Cas9-Based Genome Editing for Disease Modeling and Therapy: Challenges and Opportunities for Nonviral Delivery

Genome editing offers promising solutions to genetic disorders by editing DNA sequences or modulating gene expression. The clustered regularly interspaced short palindromic repeats (CRISPR)/associated protein 9 (CRISPR/Cas9) technology can be used to edit single or multiple genes in a wide variety of cell types and organisms in vitro and in vivo. Herein, we review the rapidly developing CRISPR/Cas9-based technologies for disease modeling and gene correction and recent progress toward Cas9/guide RNA (gRNA) delivery based on viral and nonviral vectors. We discuss the relative merits of delivering the genome editing elements in the form of DNA, mRNA, or protein, and the opportunities of combining viral delivery of a transgene encoding Cas9 with nonviral delivery of gRNA. We highlight the lessons learned from nonviral gene delivery in the past three decades and consider their applicability for CRISPR/Cas9 delivery. We also include a discussion of bioinformatics tools for gRNA design and chemical modifications of gRNA. Finally, we consider the extracellular and intracellular barriers to nonviral CRISPR/Cas9 delivery and propose strategies that may overcome these barriers to realize the clinical potential of CRISPR/Cas9-based genome editing.

Preclinical and Clinical Demonstration of Immunogenicity by mRNA Vaccines against H10N8 and H7N9 Influenza Viruses

Recently, the World Health Organization confirmed 120 new human cases of avian H7N9 influenza in China resulting in 37 deaths, highlighting the concern for a potential pandemic and the need for an effective, safe, and high-speed vaccine production platform. Production speed and scale of mRNA-based vaccines make them ideally suited to impede potential pandemic threats. Here we show that lipid nanoparticle (LNP)-formulated, modified mRNA vaccines, encoding hemagglutinin (HA) proteins of H10N8 (A/Jiangxi-Donghu/346/2013) or H7N9 (A/Anhui/1/2013), generated rapid and robust immune responses in mice, ferrets, and nonhuman primates, as measured by hemagglutination inhibition (HAI) and microneutralization (MN) assays. A single dose of H7N9 mRNA protected mice from a lethal challenge and reduced lung viral titers in ferrets. Interim results from a first-in-human, escalating-dose, phase 1 H10N8 study show very high seroconversion rates, demonstrating robust prophylactic immunity in humans. Adverse events (AEs) were mild or moderate with only a few severe and no serious events. These data show that LNP-formulated, modified mRNA vaccines can induce protective immunogenicity with acceptable tolerability profiles.

Macromolecular systems for vaccine delivery

Vaccines have helped considerably in eliminating some life-threatening infectious diseases in past two hundred years. Recently, human medicine has focused on vaccination against some of the world's most common infectious diseases (AIDS, malaria, tuberculosis, etc.), and vaccination is also gaining popularity in the treatment of cancer or autoimmune diseases. The major limitation of current vaccines lies in their poor ability to generate a sufficient level of protective antibodies and T cell responses against diseases such as HIV, malaria, tuberculosis and cancers. Among the promising vaccination systems that could improve the potency of weakly immunogenic vaccines belong macromolecular carriers (water soluble polymers, polymer particels, micelles, gels etc.) conjugated with antigens and immunistumulatory molecules. The size, architecture, and the composition of the high molecular-weight carrier can significantly improve the vaccine efficiency. This review includes the most recently developed (bio)polymer-based vaccines reported in the literature.

Type I Interferons Modulate CD8+ T Cell Immunity to mRNA Vaccines

mRNA vaccines have emerged as potent tools to elicit antitumor T cell immunity. They are characterized by a strong induction of type I interferons (IFNs), potent inflammatory cytokines affecting T cell differentiation and survival. Recent reports have attributed opposing roles for type I IFNs in modulating CD8+ T cell immunity to mRNA vaccines, from profoundly stimulatory to strongly inhibitory. The mechanisms behind this duality are unclear. Disentangling the factors governing the beneficial or detrimental impact of type I IFNs on CD8+ T cell responses is vital to the design of mRNA vaccines of increased potency. In light of recent advancements regarding the complex role of type I IFNs in regulating CD8+ T cell immunity to infectious diseases, we posit that the dual outcome of type I IFNs on CD8+ T cell responses to mRNA vaccination is determined by the timing and intensity of type I IFN induction relative to T cell receptor (TCR) activation.

mRNA-Based Therapeutics - Advances and Perspectives

In this review we discuss features of mRNA synthesis and modifications used to minimize immune response and prolong efficiency of the translation process in vivo. Considerable attention is given to the use of liposomes and nanoparticles containing lipids and polymers for the mRNA delivery. Finally we briefly discuss mRNAs which are currently in the clinical trials for cancer immunotherapy, vaccination against infectious diseases, and replacement therapy.

Adjuvant effects of a sequence-engineered mRNA vaccine: translational profiling demonstrates similar human and murine innate response

Background

Prophylactic and therapeutic vaccines often depend upon a strong activation of the innate immune system to drive a potent adaptive immune response, often mediated by a strong adjuvant. For a number of adjuvants immunological readouts may not be consistent across species.

Methods

In this study, we evaluated the innate immunostimulatory potential of mRNA vaccines in both humans and mice, using a novel mRNA-based vaccine encoding influenza A hemagglutinin of the pandemic strain H1N1pdm09 as a model. This evaluation was performed using an in vitro model of human innate immunity and in vivo in mice after intradermal injection.

Results

Results suggest that immunostimulation from the mRNA vaccine in humans is similar to that in mice and acts through cellular RNA sensors, with genes for RLRs [ddx58 (RIG-1) and ifih1 (MDA-5)], TLRs (tlr3, tlr7, and tlr8-human only), and CLRs (clec4gp1, clec2d, cledl1) all significantly up-regulated by the mRNA vaccine. The up-regulation of TLR8 and TLR7 points to the involvement of both mDCs and pDCs in the response to the mRNA vaccine in humans. In both humans and mice activation of these pathways drove maturation and activation of immune cells as well as production of cytokines and chemokines known to attract and activate key players of the innate and adaptive immune system.

Conclusion

This translational approach not only allowed for identification of the basic mechanisms of self-adjuvantation from the mRNA vaccine but also for comparison of the response across species, a response that appears relatively conserved or at least convergent between the in vitro human and in vivo mouse models.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-016-1111-6) contains supplementary material, which is available to authorized users.

Distinct transcriptional changes in non-small cell lung cancer patients associated with multi-antigenic RNActive® CV9201 immunotherapy

We recently completed a phase I/IIa trial of RNActive® CV9201, a novel mRNA-based therapeutic vaccine targeting five tumor-associated antigens in non-small cell lung cancer (NSCLC) patients. The aim of the study presented here was to comprehensively analyze changes in peripheral blood during the vaccination period and to generate hypotheses facilitating the identification of potential biomarkers correlating with differential clinical outcomes post RNActive® immunotherapy. We performed whole-genome expression profiling in a subgroup of 22 stage IV NSCLC patients before and after initiation of treatment with CV9201. Utilizing an analytic approach based on blood transcriptional modules (BTMs), a previously described, sensitive tool for blood transcriptome data analysis, patients segregated into two major clusters based on transcriptional changes post RNActive® treatment. The first group of patients was characterized by the upregulation of an expression signature associated with myeloid cells and inflammation, whereas the other group exhibited an expression signature associated with T and NK cells. Patients with an enrichment of T and NK cell modules after treatment compared to baseline exhibited significantly longer progression-free and overall survival compared to patients with an upregulation of myeloid cell and inflammatory modules. Notably, these gene expression signatures were mutually exclusive and inversely correlated. Furthermore, our findings correlated with phenotypic data derived by flow cytometry as well as the neutrophil-to-lymphocyte ratio. Our study thus demonstrates non-overlapping, distinct transcriptional profiles correlating with survival warranting further validation for the development of biomarker candidates for mRNA-based immunotherapy.

Rational design of protamine nanocapsules as antigen delivery carriers

Current challenges in global immunization indicate the demand for new delivery strategies, which could be applied to the development of new vaccines against emerging diseases, as well as to improve safety and efficacy of currently existing vaccine formulations. Here, we report a novel antigen nanocarrier consisting of an oily core and a protamine shell, further stabilized with pegylated surfactants. These nanocarriers, named protamine nanocapsules, were rationally designed to promote the intracellular delivery of antigens to immunocompetent cells and to trigger an efficient and long-lasting immune response. Protamine nanocapsules have nanometric size, positive zeta potential and high association capacity for H1N1 influenza hemagglutinin, a protein that was used here as a model antigen. The new formulation shows an attractive stability profile both, as an aqueous suspension or a freeze-dried powder formulation. In vitro studies showed that protamine nanocapsules were efficiently internalized by macrophages without eliciting significant toxicity. In vivo studies indicate that antigen-loaded nanocapsules trigger immune responses comparable to those achieved with alum, even when using significantly lower antigen doses, thus indicating their adjuvant properties. These promising in vivo data, alongside with their versatility for the loading of different antigens and oily immunomodulators and their excellent stability profile, make these nanocapsules a promising platform for the delivery of antigens.

CHEMICAL COMPOUNDS

Protamine sulphate (PubChem SID: 7849283), Sodium Cholate (PubChem CID: 23668194), Miglyol (PubChem CID: 53471835), α tocopherol (PubChem CID: 14985), Tween® 20(PubChem CID: 443314), Tween® 80(PubChem CID: 5281955), TPGS (PubChem CID: 71406).

Dendrimer-RNA nanoparticles generate protective immunity against lethal Ebola, H1N1 influenza, and Toxoplasma gondii challenges with a single dose

Vaccines have had broad medical impact, but existing vaccine technologies and production methods are limited in their ability to respond rapidly to evolving and emerging pathogens, or sudden outbreaks. Here, we develop a rapid-response, fully synthetic, single-dose, adjuvant-free dendrimer nanoparticle vaccine platform wherein antigens are encoded by encapsulated mRNA replicons. To our knowledge, this system is the first capable of generating protective immunity against a broad spectrum of lethal pathogen challenges, including H1N1 influenza, Toxoplasma gondii, and Ebola virus. The vaccine can be formed with multiple antigen-expressing replicons, and is capable of eliciting both CD8(+) T-cell and antibody responses. The ability to generate viable, contaminant-free vaccines within days, to single or multiple antigens, may have broad utility for a range of diseases.

An mRNA Vaccine Encoding Rabies Virus Glycoprotein Induces Protection against Lethal Infection in Mice and Correlates of Protection in Adult and Newborn Pigs

Rabies is a zoonotic infectious disease of the central nervous system (CNS). In unvaccinated or untreated subjects, rabies virus infection causes severe neurological symptoms and is invariably fatal. Despite the long-standing existence of effective vaccines, vaccine availability remains insufficient, with high numbers of fatal infections mostly in developing countries. Nucleic acid based vaccines have proven convincingly as a new technology for the fast development of vaccines against newly emerging pathogens, diseases where no vaccine exists or for replacing already existing vaccines. We used an optimized non-replicating rabies virus glycoprotein (RABV-G) encoding messenger RNA (mRNA) to induce potent neutralizing antibodies (VN titers) in mice and domestic pigs. Functional antibody titers were followed in mice for up to one year and titers remained stable for the entire observation period in all dose groups. T cell analysis revealed the induction of both, specific CD4+ as well as CD8+ T cells by RABV-G mRNA, with the induced CD4+ T cells being higher than those induced by a licensed vaccine. Notably, RABV-G mRNA vaccinated mice were protected against lethal intracerebral challenge infection. Inhibition of viral replication by vaccination was verified by qRT-PCR. Furthermore, we demonstrate that CD4+ T cells are crucial for the generation of neutralizing antibodies. In domestic pigs we were able to induce VN titers that correlate with protection in adult and newborn pigs. This study demonstrates the feasibility of a non-replicating mRNA rabies vaccine in small and large animals and highlights the promises of mRNA vaccines for the prevention of infectious diseases.

Self-adjuvanted mRNA vaccines induce local innate immune responses that lead to a potent and boostable adaptive immunity

mRNA represents a new platform for the development of therapeutic and prophylactic vaccines with high flexibility with respect to production and application. We have previously shown that our two component self-adjuvanted mRNA-based vaccines (termed RNActive® vaccines) induce balanced immune responses comprising both humoral and cellular effector as well as memory responses. Here, we evaluated the early events upon intradermal application to gain more detailed insights into the underlying mode of action of our mRNA-based vaccine. We showed that the vaccine is taken up in the skin by both non-leukocytic and leukocytic cells, the latter being mostly represented by antigen presenting cells (APCs). mRNA was then transported to the draining lymph nodes (dLNs) by migratory dendritic cells. Moreover, the encoded protein was expressed and efficiently presented by APCs within the dLNs as shown by T cell proliferation and immune cell activation, followed by the induction of the adaptive immunity. Importantly, the immunostimulation was limited to the injection site and lymphoid organs as no proinflammatory cytokines were detected in the sera of the immunized mice indicating a favorable safety profile of the mRNA-based vaccines. Notably, a substantial boostability of the immune responses was observed, indicating that mRNA can be used effectively in repetitive immunization schedules. The evaluation of the immunostimulation following prime and boost vaccination revealed no signs of exhaustion as demonstrated by comparable levels of cytokine production at the injection site and immune cell activation within dLNs. In summary, our data provide mechanistic insight into the mode of action and a rational for the use of mRNA-based vaccines as a promising immunization platform.

Universal influenza vaccines: Shifting to better vaccines

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Current influenza vaccines are not broadly protective.

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Developing countries suffer the highest morbidity and mortality due to influenza.

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Correlates of protection and a regulatory pathway must be identified.

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Over 40 universal influenza vaccine candidates are currently in development.

Influenza virus causes acute upper and lower respiratory infections and is the most likely, among known pathogens, to cause a large epidemic in humans. Influenza virus mutates rapidly, enabling it to evade natural and vaccine-induced immunity. Furthermore, influenza viruses can cross from animals to humans, generating novel, potentially pandemic strains. Currently available influenza vaccines induce a strain specific response and may be ineffective against new influenza viruses. The difficulty in predicting circulating strains has frequently resulted in mismatch between the annual vaccine and circulating viruses. Low-resource countries remain mostly unprotected against seasonal influenza and are particularly vulnerable to future pandemics, in part, because investments in vaccine manufacturing and stockpiling are concentrated in high-resource countries. Antibodies that target conserved sites in the hemagglutinin stalk have been isolated from humans and shown to confer protection in animal models, suggesting that broadly protective immunity may be possible. Several innovative influenza vaccine candidates are currently in preclinical or early clinical development. New technologies include adjuvants, synthetic peptides, virus-like particles (VLPs), DNA vectors, messenger RNA, viral vectors, and attenuated or inactivated influenza viruses. Other approaches target the conserved exposed epitope of the surface exposed membrane matrix protein M2e. Well-conserved influenza proteins, such as nucleoprotein and matrix protein, are mainly targeted for developing strong cross-protective T cell responses. With multiple vaccine candidates moving along the testing and development pipeline, the field is steadily moving toward a product that is more potent, durable, and broadly protective than previously licensed vaccines.

mRNA Cancer Vaccines

mRNA cancer vaccines are a relatively new class of vaccines, which combine the potential of mRNA to encode for almost any protein with an excellent safety profile and a flexible production process. The most straightforward use of mRNA vaccines in oncologic settings is the immunization of patients with mRNA vaccines encoding tumor-associated antigens (TAAs). This is exemplified by the RNActive^® technology, which induces balanced humoral and cellular immune responses in animal models and is currently evaluated in several clinical trials for oncologic indications. A second application of mRNA vaccines is the production of personalized vaccines. This is possible because mRNA vaccines are produced by a generic process, which can be used to quickly produce mRNA vaccines targeting patient-specific neoantigens that are identified by analyzing the tumor exome. Apart from being used directly to vaccinate patients, mRNAs can also be used in cellular therapies to transfect patient-derived cells in vitro and infuse the manipulated cells back into the patient. One such application is the transfection of patient-derived dendritic cells (DCs) with mRNAs encoding TAAs, which leads to the presentation of TAA-derived peptides on the DCs and an activation of antigen-specific T cells in vivo. A second application is the transfection of patient-derived T cells with mRNAs encoding chimeric antigen receptors, which allows the T cells to directly recognize a specific antigen expressed on the tumor. In this chapter, we will review preclinical and clinical data for the different approaches.

Materials for non-viral intracellular delivery of messenger RNA therapeutics

Though therapeutics based on messenger RNA (mRNA) have broad potential in applications such as protein replacement therapy, cancer immunotherapy, and genomic engineering, their effective intracellular delivery remains a challenge. A chemically diverse suite of delivery materials with origins as materials for cellular transfection of DNA and small interfering RNAs (siRNAs) has recently been reported to have promise as non-viral delivery agents for mRNA. These materials include covalent conjugates, protamine complexes, nanoparticles based on lipids or polymers, and hybrid formulations. This review will highlight the use of delivery materials for mRNA, with a specific focus on their mechanisms of action, routes of administration, and dosages. Additionally, strategies in which these materials can be adapted and optimized to address challenges specific to mRNA delivery are also discussed. The technologies included have shown varying promise for therapeutic use, specifically having been used to deliver mRNA in vivo or exhibiting characteristics that could make in vivo use a possibility. In so doing, it is the intention of this review to provide a comprehensive look at the progress and possibilities in applying nucleic acid delivery technology specifically toward the emerging area of mRNA therapeutics.

Long-term survival correlates with immunological responses in renal cell carcinoma patients treated with mRNA-based immunotherapy

Renal cell carcinoma (RCC) is an immunogenic tumor for which immunotherapeutic approaches could be associated with clinically relevant responses. It was recently shown, that induction of T-cell responses against multiple tumor-associated antigen (TAA) epitopes results in prolonged overall survival in RCC patients. In 2003–2005, we performed a phase I/II trial testing an mRNA-based vaccine formulation consisting of a mixture of in vitro transcribed RNA coding for six different TAAs (MUC1, CEA, Her2/neu, telomerase, survivin, MAGE-A1) in 30 metastatic RCC (mRCC) patients. In the first 14 patients, vaccinations were applied i.d. on days 0, 14, 28, and 42. In the consecutive 16 patients, an intensified protocol consisting of i.d. injections (daily on days 0–3, 7–10, 28, and 42) was used. After the respective induction periods, patients in both cohorts were vaccinated monthly until tumor progression. At survival update performed in July 2015, one of the 30 patients was still alive. One patient was lost to follow-up. Median survival of 24.5 mo (all patients) and 89 mo (favorable risk patients) exceeded predicted survival according to Memorial Sloan Kettering Cancer Center (MSKCC) risk score. Impressively, long-term survivors displayed immunological responses to the applied antigens while vice versa no patient without detectable immune response had survived more than 33 mo. The current survival update shows a clear correlation between survival and immunological responses to TAAs encoded by the naked mRNA vaccine. This is one of the first vaccination studies and the only RNA trial that reports on safety and efficacy after a follow-up of more than 10 y.

Nucleic acid vaccination strategies against infectious diseases

INTRODUCTION

Gene vaccines are an interesting and emerging alternative for the prevention of infectious diseases, as well as in the treatment of other pathologies including cancer, allergies, autoimmune diseases, or even drug dependencies. When applied to the target organism, these vaccines induce the expression of encoded antigens and elicit the corresponding immune response, with the potential ability of being able to induce antibody-, helper T cell-, and cytotoxic T cell-mediated immune responses.

AREAS COVERED

Special attention is paid to the variety of adjuvants that may be co-administered to enhance and/or to modulate immune responses, and to the methods of delivery. Finally, this article reviews the efficacy data of gene vaccines against infectious diseases released from current clinical trials.

EXPERT OPINION

Taken together, this approach will have a major impact on future strategies for the prevention of infectious diseases. Better-designed nucleic acid constructs, novel delivery technologies, as well as the clarification of the mechanisms for antigen presentation will improve the potential applications of this vaccination strategy against microbial pathogens.

Bridging infectious disease vaccines with cancer immunotherapy: a role for targeted RNA based immunotherapeutics

Tumor-specific immunotherapy holds the promise of eradicating malignant tumors with exquisite precision without additional toxicity to standard treatments. Cancer immunotherapy has conventionally relied on cell-mediated immunity while successful infectious disease vaccines have been shown to induce humoral immunity. Efficacious cancer immunotherapeutics likely require both cellular and humoral responses, and RNA based cancer vaccines are especially suited to stimulate both arms of the immune system. RNA is inherently immunogenic, inducing innate immune responses to initiate cellular and humoral adaptive immunity, but has limited utility based on its poor in vivo stability. Early work utilized ‘naked’ RNA vaccines, whereas more recent efforts have attempted to encapsulate RNA thereby protecting it from degradation. However, feasibility has been limited by a lack of defined and safe targeting mechanisms for the in vivo delivery of stabilized RNA. As new cancer antigens come to the forefront with novel RNA encapsulation and targeting techniques, RNA vaccines may prove to be a vital, safe and robust method to initiate patient-specific anti-tumor efficacy.

Trial Watch: Radioimmunotherapy for oncological indications

During the past two decades, it has become increasingly clear that the antineoplastic effects of radiation therapy do not simply reflect the ability of X-, β- and γ-rays to damage transformed cells and directly cause their permanent proliferative arrest or demise, but also involve cancer cell-extrinsic mechanisms. Indeed, among other activities, radiotherapy has been shown to favor the establishment of tumor-specific immune responses that operate systemically, underpinning the so-called 'out-of-field' or 'abscopal' effect. Thus, ionizing rays appear to elicit immunogenic cell death, a functionally peculiar variant of apoptosis associated with the emission of a particularly immunostimulatory combination of damage-associated molecular patterns. In line with this notion, radiation therapy fosters, and thus exacerbates, the antineoplastic effects of various treatment modalities, including surgery, chemotherapy and various immunotherapeutic agents. Here, we summarize recent advances in the use of ionizing rays as a means to induce or potentiate therapeutically relevant anticancer immune responses. In addition, we present clinical trials initiated during the past 12 months to test the actual benefit of radioimmunotherapy in cancer patients.

Phase Ib study evaluating a self-adjuvanted mRNA cancer vaccine (RNActive®) combined with local radiation as consolidation and maintenance treatment for patients with stage IV non-small cell lung cancer

BACKGROUND

Advanced non-small cell lung cancer (NSCLC) represents a significant unmet medical need. Despite advances with targeted therapies in a small subset of patients, fewer than 20% of patients survive for more than two years after diagnosis. Cancer vaccines are a promising therapeutic approach that offers the potential for durable responses through the engagement of the patient's own immune system. CV9202 is a self-adjuvanting mRNA vaccine that targets six antigens commonly expressed in NSCLC (NY-ESO-1, MAGEC1, MAGEC2, 5 T4, survivin, and MUC1).

METHODS/DESIGN

The trial will assess the safety and tolerability of CV9202 vaccination combined with local radiation designed to enhance immune responses and will include patients with stage IV NSCLC and a response or stable disease after first-line chemotherapy or therapy with an EGFR tyrosine kinase inhibitor. Three histological and molecular subtypes of NSCLC will be investigated (squamous and non-squamous cell with/without EGFR mutations). All patients will receive two initial vaccinations with CV9202 prior to local radiotherapy (5 GY per day for four successive days) followed by further vaccinations until disease progression. The primary endpoint of the study is the number of patients experiencing Grade >3 treatment-related adverse events. Pharmacodynamic analyses include the assessment of immune responses to the antigens encoded by CV9202 and others not included in the panel (antigen spreading) and standard efficacy assessments.

DISCUSSION

RNActive self-adjuvanted mRNA vaccines offer the potential for simultaneously inducing immune responses to a wide panel of antigens commonly expressed in tumors. This trial will assess the feasibility of this approach in combination with local radiotherapy in NSCLC patients.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT01915524/EudraCT No.: 2012-004230-41.