mRNA Therapies

INTRODUCTION: In light of the SARS-CoV-2 pandemic, protecting vulnerable groups has become a high priority. Persons at risk of severe disease, for example, those receiving immunosuppressive therapies for chronic inflammatory cdiseases (CIDs), are prioritised for vaccination. However, data concerning generation of protective antibody titres in immunosuppressed patients are scarce. Additionally, mRNA vaccines represent a new vaccine technology leading to increased insecurity especially in patients with CID. OBJECTIVE: Here we present for the first time, data on the efficacy and safety of anti-SARS-CoV-2 mRNA vaccines in a cohort of immunosuppressed patients as compared with healthy controls. METHODS: 42 healthy controls and 26 patients with CID were included in this study (mean age 37.5 vs 50.5 years). Immunisations were performed according to national guidelines with mRNA vaccines. Antibody titres were assessed by ELISA before initial vaccination and 7 days after secondary vaccination. Disease activity and side effects were assessed prior to and 7 days after both vaccinations. RESULTS: Anti-SARS-CoV-2 antibodies as well as neutralising activity could be detected in all study participants. IgG titres were significantly lower in patients as compared with controls (2053 binding antibody units (BAU)/mL ±1218 vs 2685±1102). Side effects were comparable in both groups. No severe adverse effects were observed, and no patients experienced a disease flare. CONCLUSION: We show that SARS-CoV-2 mRNA vaccines lead to development of antibodies in immunosuppressed patients without considerable side effects or induction of disease flares. Despite the small size of this cohort, we were able to demonstrate the efficiency and safety of mRNA vaccines in our cohort.

BACKGROUND AND AIMS: The National Multiple Sclerosis Society and other expert organizations recommended that all patients with multiple sclerosis (MS) should be vaccinated against COVID-19. However, the effect of disease-modifying therapies (DMTs) on the efficacy to mount an appropriate immune response is unknown. We aimed to characterize humoral immunity in mRNA-COVID-19 MS vaccinees treated with high-efficacy DMTs. METHODS: We measured SARS-CoV-2 IgG response using anti-spike protein-based serology (EUROIMMUN) in 125 MS patients vaccinated with BNT162b2-COVID-19 vaccine 1 month after the second dose. Patients were either untreated or under treatment with fingolimod, cladribine, or ocrelizumab. A group of healthy subjects similarly vaccinated served as control. The percent of subjects that developed protective antibodies, the titer, and the time from the last dosing were evaluated. RESULTS: = 26), respectively. SARS-CoV-2 IgG antibody titer was high in healthy subjects, untreated MS patients, and MS patients under cladribine treatment, within 29.5-55 days after the second vaccine dose. Only 22.7% of patients treated with ocrelizumab developed humoral IgG response irrespective to normal absolute lymphocyte count. Most fingolimod-treated MS patients had very low lymphocyte count and failed to develop SARS-COV-2 antibodies. Age, disease duration, and time from the last dosing did not affect humoral response to COVID-19 vaccination. CONCLUSIONS: Cladribine treatment does not impair humoral response to COVID-19 vaccination. We recommend postponing ocrelizumab treatment in MS patients willing to be vaccinated as a protective humoral response can be expected only in some. We do not recommend vaccinating MS patients treated with fingolimod as a protective humoral response is not expected.

Data are scarce regarding both the safety and immunogenicity of the BNT162b2 mRNA COVID-19 vaccine in patients undergoing immune cell therapy; thus, we prospectively evaluated these two domains in patients receiving this vaccine after allogeneic hematopoietic cell transplantation (HCT; n = 66) or after CD19-based chimeric antigen receptor T cell (CART) therapy (n = 14). Overall, the vaccine was well tolerated, with mild non-hematologic vaccine-reported adverse events in a minority of the patients. Twelve percent of the patients after the first dose and 10% of the patients after the second dose developed cytopenia, and there were three cases of graft-versus-host disease exacerbation after each dose. A single case of impending graft rejection was summarized as possibly related. Evaluation of immunogenicity showed that 57% of patients after CART infusion and 75% patients after allogeneic HCT had evidence of humoral and/or cellular response to the vaccine. The Cox regression model indicated that longer time from infusion of cells, female sex, and higher CD19+ cells were associated with a positive humoral response, whereas a higher CD4+/CD8+ ratio was correlated with a positive cellular response, as confirmed by the ELISpot test. We conclude that the BNT162b2 mRNA COVID-19 vaccine has impressive immunogenicity in patients after allogeneic HCT or CART. Adverse events were mostly mild and transient, but some significant hematologic events were observed; hence, patients should be closely monitored.

Messenger ribonucleic acid (mRNA) vaccines are a relatively new class of vaccines that have shown great promise in the immunotherapy of a wide variety of infectious diseases and cancer. In the past 2 years, SARS-CoV-2 mRNA vaccines have contributed tremendously against SARS-CoV2, which has prompted the arrival of the mRNA vaccine research boom, especially in the research of cancer vaccines. Compared with conventional cancer vaccines, mRNA vaccines have significant advantages, including efficient production of protective immune responses, relatively low side effects and lower cost of acquisition. In this review, we elaborated on the development of cancer vaccines and mRNA cancer vaccines, as well as the potential biological mechanisms of mRNA cancer vaccines and the latest progress in various tumour treatments, and discussed the challenges and future directions for the field.

Direct vaccination with mRNA encoding tumor antigens is a novel and promising approach in cancer immunotherapy. CureVac's mRNA vaccines contain free and protamine-complexed mRNA. Such two-component mRNA vaccines support both antigen expression and immune stimulation. These self-adjuvanting RNA vaccines, administered intradermally without any additional adjuvant, induce a comprehensive balanced immune response, comprising antigen specific CD4+ T cells, CD8+ T cells and B cells. The balanced immune response results in a strong anti-tumor effect and complete protection against antigen positive tumor cells. This tumor inhibition elicited by mRNA vaccines is a result of the concerted action of different players. After just two intradermal vaccinations, we observe multiple changes at the tumor site, including the up-regulation of many genes connected to T and natural killer cell activation, as well as genes responsible for improved infiltration of immune cells into the tumor via chemotaxis. The two-component mRNA vaccines induce a very fast and boostable immune response. Therefore, the vaccination schedules can be adjusted to suit the clinical situation. Moreover, by combining the mRNA vaccines with therapies in clinical use (chemotherapy or anti-CTLA-4 antibody therapy), an even more effective anti-tumor response can be elicited. The first clinical data obtained from two separate Phase I/IIa trials conducted in PCA (prostate cancer) and NSCLC (non-small cell lung carcinoma) patients have shown that the two-component mRNA vaccines are safe, well tolerated and highly immunogenic in humans.

Pancreatic cancer is characterized by inter-tumoral and intra-tumoral heterogeneity, especially in genetic alteration and microenvironment. Conventional therapeutic strategies for pancreatic cancer usually suffer resistance, highlighting the necessity for personalized precise treatment. Cancer vaccines have become promising alternatives for pancreatic cancer treatment because of their multifaceted advantages including multiple targeting, minimal nonspecific effects, broad therapeutic window, low toxicity, and induction of persistent immunological memory. Multiple conventional vaccines based on the cells, microorganisms, exosomes, proteins, peptides, or DNA against pancreatic cancer have been developed; however, their overall efficacy remains unsatisfactory. Compared with these vaccine modalities, messager RNA (mRNA)-based vaccines offer technical and conceptional advances in personalized precise treatment, and thus represent a potentially cutting-edge option in novel therapeutic approaches for pancreatic cancer. This review summarizes the current progress on pancreatic cancer vaccines, highlights the superiority of mRNA vaccines over other conventional vaccines, and proposes the viable tactic for designing and applying personalized mRNA vaccines for the precise treatment of pancreatic cancer.

Abstract Antitumor therapies based on adoptively transferred T cells or oncolytic viruses have made significant progress in recent years, but the limited efficiency of their infiltration into solid tumors makes it difficult to achieve desired antitumor effects when used alone. In this study, an oncolytic virus (rVSV-LCMVG) that is not prone to induce virus-neutralizing antibodies was designed and combined with adoptively transferred T cells. By transforming the immunosuppressive tumor microenvironment into an immunosensitive one, in B16 tumor-bearing mice, combination therapy showed superior antitumor effects than monotherapy. This occurred whether the OV was administered intratumorally or intravenously. Combination therapy significantly increased cytokine and chemokine levels within tumors and recruited CD8 + T cells to the TME to trigger antitumor immune responses. Pretreatment with adoptively transferred T cells and subsequent oncolytic virotherapy sensitizes refractory tumors by boosting T-cell recruitment, down-regulating the expression of PD-1, and restoring effector T-cell function. To offer a combination therapy with greater translational value, mRNA vaccines were introduced to induce tumor-specific T cells instead of adoptively transferred T cells. The combination of OVs and mRNA vaccine also displays a significant reduction in tumor burden and prolonged survival. This study proposed a rational combination therapy of OVs with adoptive T-cell transfer or mRNA vaccines encoding tumor-associated antigens, in terms of synergistic efficacy and mechanism.

In recent years, the use of messenger RNA (mRNA) in the fields of gene therapy, immunotherapy, and stem cell biomedicine has received extensive attention. With the development of scientific technology, mRNA applications for tumor treatment have matured. Since the SARS-CoV-2 infection outbreak in 2019, the development of engineered mRNA and mRNA vaccines has accelerated rapidly. mRNA is easy to produce, scalable, modifiable, and not integrated into the host genome, showing tremendous potential for cancer gene therapy and immunotherapy when used in combination with traditional strategies. The core mechanism of mRNA therapy is vehicle-based delivery of in vitro transcribed mRNA (IVT mRNA), which is large, negatively charged, and easily degradable, into the cytoplasm and subsequent expression of the corresponding proteins. However, effectively delivering mRNA into cells and successfully activating the immune response are the keys to the clinical transformation of mRNA therapy. In this review, we focus on nonviral nanodelivery systems of mRNA vaccines used for cancer gene therapy and immunotherapy.

BACKGROUND: The eradication of large, established tumors by active immunotherapy is a major challenge because of the numerous cancer evasion mechanisms that exist. This study aimed to establish a novel combination therapy consisting of messenger RNA (mRNA)-based cancer vaccines and radiation, which would facilitate the effective treatment of established tumors with aggressive growth kinetics. METHODS: The combination of a tumor-specific mRNA-based vaccination with radiation was tested in two syngeneic tumor models, a highly immunogenic E.G7-OVA and a low immunogenic Lewis lung cancer (LLC). The molecular mechanism induced by the combination therapy was evaluated via gene expression arrays as well as flow cytometry analyses of tumor infiltrating cells. RESULTS: In both tumor models we demonstrated that a combination of mRNA-based immunotherapy with radiation results in a strong synergistic anti-tumor effect. This was manifested as either complete tumor eradication or delay in tumor growth. Gene expression analysis of mouse tumors revealed a variety of substantial changes at the tumor site following radiation. Genes associated with antigen presentation, infiltration of immune cells, adhesion, and activation of the innate immune system were upregulated. A combination of radiation and immunotherapy induced significant downregulation of tumor associated factors and upregulation of tumor suppressors. Moreover, combination therapy significantly increased CD4+, CD8+ and NKT cell infiltration of mouse tumors. CONCLUSION: Our data provide a scientific rationale for combining immunotherapy with radiation and provide a basis for the development of more potent anti-cancer therapies.

COVID-19 vaccines were developed and approved rapidly in response to the urgency created by the pandemic. No specific regulations existed at the time they were marketed. The regulatory agencies therefore adapted them as a matter of urgency. Now that the pandemic emergency has passed, it is time to consider the safety issues associated with this rapid approval. The mode of action of COVID-19 mRNA vaccines should classify them as gene therapy products (GTPs), but they have been excluded by regulatory agencies. Some of the tests they have undergone as vaccines have produced non-compliant results in terms of purity, quality and batch homogeneity. The wide and persistent biodistribution of mRNAs and their protein products, incompletely studied due to their classification as vaccines, raises safety issues. Post-marketing studies have shown that mRNA passes into breast milk and could have adverse effects on breast-fed babies. Long-term expression, integration into the genome, transmission to the germline, passage into sperm, embryo/fetal and perinatal toxicity, genotoxicity and tumorigenicity should be studied in light of the adverse events reported in pharmacovigilance databases. The potential horizontal transmission (i.e., shedding) should also have been assessed. In-depth vaccinovigilance should be carried out. We would expect these controls to be required for future mRNA vaccines developed outside the context of a pandemic.

TPS9107 Background: Vaccine therapies stimulate the immune system to attack cancer cells (active immunotherapy), whereas checkpoint inhibitors block immune inhibition (passive immunotherapy). Several PD-1 and PD-L1 blocking antibodies are approved for NSCLC. This study combines active and passive immunotherapies to determine if the addition of a mRNA vaccine can enhance the activity of checkpoint blockade. The vaccine BI 1361849 (comprising 6 mRNAs encoding for selected tumor-associated antigens: MUC1, survivin, NY-ESO-1, 5T4, MAGE-C2 and MAGE-C1) is combined with 1 or 2 checkpoint inhibitors (durva [anti-PD-L1] ± treme [anti-CTLA-4]). Methods: This ongoing Phase 1/2, open-label study (NCT03164772) evaluates the safety and efficacy of BI 1361849 when administered with durva (Arm A) or durva + treme (Arm B) in NSCLC patients. In arm A, an initial dose-evaluation phase follows a 3+3 design to determine the dose of durva (1500 or 750 mg) to be given with the vaccine. Arm B uses the durva dose from Arm A, with the addition of 75 mg treme. In the expansion phase, 20 patients are treated in each arm. To aid in the evaluation of immune responses, there is an additional control group (n = 10), which receives the checkpoint inhibitors only. Study treatment is administered over 12 (28-day) cycles. Durva (x 12 doses) and treme (x 4 doses) are administered intravenously every 28 days. The vaccine is administered on 1 to 3 days over each of the 12 cycles using a device that provides a needle-free intradermal administration. The primary endpoint is safety/tolerability per CTCAE, including dose-limiting toxicity during dose evaluation. Secondary endpoints are progression-free survival and objective response rate at 8 and 24 weeks, disease control rate, response duration, and overall survival, with tumor response evaluated by RECIST and immune-related RECIST. Exploratory objectives include effects on tumor microenvironment and evaluation of immune responses. Enrollment opened 20Dec2017. Clinical trial information: NCT03164772.

Abstract Vaccine therapies stimulate the immune system to attack cancer cells (active immunotherapy), whereas checkpoint inhibitors block immune inhibition (passive immunotherapy). BI 1361849 (formerly CV9202) is a cancer vaccine comprising 6 mRNA constituents, each of which encodes for one of the non-small cell lung cancer (NSCLC) associated antigens: MUC1, survivin, NY-ESO-1, 5T4, MAGE-C2, and MAGE-C1. Durvalumab (durva) is a checkpoint inhibitor that blocks programmed cell death ligand-1 (PD-L1) binding to programmed cell death-1 (PD-1). Several PD-1 and PD-L1 blocking antibodies are approved for NSCLC. Tremelimumab (treme) is an anti-cytotoxic T-lymphocyte-associated antigen-4 (anti-CTLA-4) blocking antibody. Targeting both the CTLA-4 and PD-1 checkpoint pathways provides the potential for additive or synergistic effects. This study combines active and passive immunotherapies to determine if the addition of a mRNA vaccine, BI 1361849, can enhance the activity of checkpoint blockade. This ongoing phase 1/2, open-label study (NCT03164772) evaluates the safety and efficacy of BI 1361849 when administered with durva (Arm A) or durva + treme (Arm B) in patients with NSCLC. In Arm A, an initial dose evaluation phase follows a 3+3 design to confirm the dose of durva (full dose 1500 mg or de-escalated 750 mg, if needed) to be given with the vaccine. Arm B uses the dose established in Arm A, with the addition of 75 mg treme. In the expansion phase, 20 patients are treated in each arm. To aid in the evaluation of immune responses, there is an additional control group (n=10), in which patients receive the checkpoint inhibitor(s) only. Study treatment is administered over 12 cycles (28 days each). Durva (x 12 doses) and treme (x 4 doses, Arm B only) are administered intravenously every 28 days. The vaccine is administered as a total of 14 doses (of the 6 components) during the 12 cycles, using a device that provides a needle-free intradermal administration. The primary endpoint is assessment of safety and tolerability, including evaluation of dose-limiting toxicities. Secondary endpoints include progression-free survival and objective response rate at 8 and 24 weeks, disease control rate, response duration, and overall survival, with tumor response evaluated by RECIST 1.1 and immune-related RECIST. Exploratory objectives include effects on tumor microenvironment and evaluation of immune responses. Enrollment opened 20 December 2017. As of 27 June 2018, 2 patients are enrolled; enrollment is ongoing. Citation Format: Joshua Sabari, Kristen Aufiero Ramirez, Paul Schwarzenberger, Toni Ricciardi, Mary Macri, Aileen Ryan, Ralph Venhaus. Phase 1/2 study of mRNA vaccine therapy + durvalumab (durva) ± tremelimumab (treme) in patients with metastatic non-small cell lung cancer (NSCLC) [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr B209.

Breast cancer represents the most prevalent cancer among women globally, constituting approximately 30% of newly diagnosed female malignancies and serving as the second leading cause of cancer-related mortality, accounting for 11.6% of deaths. Despite notable advancements in survival rates and quality of life for breast cancer patients over recent decades-achieved through interventions such as surgery, chemotherapy, radiotherapy, and endocrine therapy-there remains an urgent need for novel therapeutic strategies. This necessity arises from challenges associated with recurrence, metastasis, and drug resistance. The COVID-19 pandemic has accelerated the development of Messenger RNA (mRNA) vaccines at an unprecedented pace, and as a novel form of precision immunotherapy, mRNA vaccines are increasingly being recognized for their potential in cancer treatment. mRNA vaccines efficiently produce antigens within the cytoplasm, specifically activating the immune system to target tumor cells while minimizing the risk of T-cell tolerance. Therefore, mRNA vaccines have emerged as a promising approach in cancer immunotherapy. This review systematically examines the principles, mechanisms, advantages, key targets, and recent progress in mRNA vaccine therapy for breast cancer. Furthermore, it discusses current challenges and suggests potential directions for future research.