Vaccines For Treatment Of Cancer Research Articles

Virus Particles and Virus-like Particles-based Vaccines for Cancer Treatment

Virus Particles and Virus-like Particles-based Vaccines for Cancer Treatment

Assessment of feasibility of mRNA vaccines for cancer treatment

Cancer is the group of disease that has high morbidity rate, the traditional treatment people keep using have a lot of limitations. Although the concept of mRNA vaccines has just emerged in the 20th century, it has demonstrated its good availability during the COVID-19 pandemic. From this, researchers infer that mRNA also has great application prospects in other areas, and cancer immunotherapy has become one of them. mRNA vaccine used to have low translation efficiency and strong mRNA immunogenicity but recent research about mRNA sequence optimization could overcome most of these problems. But to apply this platform vaccine to target tumour cells specifically, the target chosen is very important and still needs a lot of research about it. This article reviews the current approach to mRNA vaccine and its therapeutic usage for cancer. Based on the current clinical studies, the mRNA vaccine might be a good auxiliary tool for cancer treatment.

Progress of DC Vaccine for Cancer Treatment

Cancer refers to malignant tumors with biological characteristics such as abnormal cell differentiation and proliferation, uncontrolled growth, infiltration, and metastasis. Its occurrence is a complex process with multiple factors and steps. In September 2022, a study conducted by American scientists showed that the incidence rate of cancer had risen sharply worldwide since 1990.How to treat cancer has become a hot topic in recent years. The article mainly introduces the development history of cancer and its treatment methods, as well as the specific methods of using dendritic cell (DC) vaccines to treat cancer and how to make DC vaccines. DC are the cells with the strongest antigen-presenting ability in the human body. Usually, the number of DC cells in the human body is very small. Only when antigen-presenting cells can perform their antigen-presenting function normally can the body effectively recognize pathogens, activate the acquired immune system, and produce normal immune responses. DC cell therapy involves inducing the generation of DC by culturing patient autologous monocytes in vitro, then loading corresponding tumor antigens to produce DC loaded with tumor antigens. These DC cells are then injected into the body to stimulate the proliferation of tumor killing lymphocytes, exerting long-term tumor monitoring and tumor killing effects, and achieving the goal of eliminating tumors. Compared with other cancer treatment methods, DC is one of the most effective ways to stimulate the body's immune system and resist cancer invasion. As a highly specialized primary antigen presenting cell, it plays a key role in inducing efficient and specific T cell immune responses against related antigens.

Application of Nanotechnology in Therapeutic Cancer Vaccines

Cancer vaccines stimulate the immune system within the body by introducing tumor antigens in various forms, such as tumor cells, tumor‐related proteins or peptides, and genes expressing tumor antigens, into the body. This activation of the immune response aims to prevent or treat tumors. Preventive cancer vaccines are primarily targeted at cancers caused by viral infections, and most cancer vaccines are currently designed as therapeutic vaccines for cancer treatment. In this review, the development of cancer vaccines, the mechanism of action, the types of antigens, and the progress of nanotechnology in therapeutic cancer vaccines are summarized. The development and application of cancer vaccines incorporating tumor‐specific antigens and nanomaterials are anticipated.

Adjuvant physiochemistry and advanced nanotechnology for vaccine development.

Vaccines comprising innovative adjuvants are rapidly reaching advanced translational stages, such as the authorized nanotechnology adjuvants in mRNA vaccines against COVID-19 worldwide, offering new strategies to effectively combat diseases threatening human health. Adjuvants are vital ingredients in vaccines, which can augment the degree, extensiveness, and longevity of antigen specific immune response. The advances in the modulation of physicochemical properties of nanoplatforms elevate the capability of adjuvants in initiating the innate immune system and adaptive immunity, offering immense potential for developing vaccines against hard-to-target infectious diseases and cancer. In this review, we provide an essential introduction of the basic principles of prophylactic and therapeutic vaccination, key roles of adjuvants in augmenting and shaping immunity to achieve desired outcomes and effectiveness, and the physiochemical properties and action mechanisms of clinically approved adjuvants for humans. We particularly focus on the preclinical and clinical progress of highly immunogenic emerging nanotechnology adjuvants formulated in vaccines for cancer treatment or infectious disease prevention. We deliberate on how the immune system can sense and respond to the physicochemical cues (e.g., chirality, deformability, solubility, topology, and chemical structures) of nanotechnology adjuvants incorporated in the vaccines. Finally, we propose possible strategies to accelerate the clinical implementation of nanotechnology adjuvanted vaccines, such as in-depth elucidation of nano-immuno interactions, antigen identification and optimization by the deployment of high-dimensional multiomics analysis approaches, encouraging close collaborations among scientists from different scientific disciplines and aggressive exploration of novel nanotechnologies.

Proposed Experimental Preparation and Administration of Dendritic Cell Vaccine for Treatment of Cancer (Metastatic Castration-Resistant Prostate Cancer)

It is suggested that a cause of inefficacy in dendritic cell vaccine is dendritic cell dysfunction. It is proposed that dendritic cell dysfunction is possibly due to the immune-regulatory function of activated platelets in cancer patients. It is suggested that activated platelets in cancer patient suppress dendritic cell activity against a malignant growth. A low platelet count prior to the removal of dendritic cells would possibly yield less dysfunctional dendritic cells.

Clinical advances and ongoing trials on mRNA vaccines for cancer treatment.

Years of research exploring mRNA vaccines for cancer treatment in preclinical and clinical trials have set the stage for the rapid development of mRNA vaccines during the COVID-19 pandemic. Therapeutic cancer vaccines based on mRNA are well tolerated, and the inherent advantage in ease of production, which rivals the best available conventional vaccine manufacture methods, renders mRNA vaccines a promising option for cancer immunotherapy. Technological advances have optimised mRNA-based vaccine stability, structure, and delivery methods, and multiple clinical trials investigating mRNA vaccine therapy are now enrolling patients with various cancer diagnoses. Although therapeutic mRNA-based cancer vaccines have not yet been approved for standard treatment, encouraging results from early clinical trials with mRNA vaccines as monotherapy and in combination with checkpoint inhibitors have been obtained. This Review summarises the latest clinical advances in mRNA-based vaccines for cancer treatment and reflects on future perspectives and challenges for this new and promising treatment approach.

Stability Program in Dendritic Cell Vaccines: A "Real-World" Experience in the Immuno-Gene Therapy Factory of Romagna Cancer Center.

Advanced therapy medical products (ATMPs) are rapidly growing as innovative medicines for the treatment of several diseases. Hence, the role of quality analytical tests to ensure consistent product safety and quality has become highly relevant. Several clinical trials involving dendritic cell (DC)-based vaccines for cancer treatment are ongoing at our institute. The DC-based vaccine is prepared via CD14+ monocyte differentiation. A fresh dose of 10 million DCs is administered to the patient, while the remaining DCs are aliquoted, frozen, and stored in nitrogen vapor for subsequent treatment doses. To evaluate the maintenance of quality parameters and to establish a shelf life of frozen vaccine aliquots, a stability program was developed. Several parameters of the DC final product at 0, 6, 12, 18, and 24 months were evaluated. Our results reveal that after 24 months of storage in nitrogen vapor, the cell viability is in a range between 82% and 99%, the expression of maturation markers remains inside the criteria for batch release, the sterility tests are compliant, and the cell costimulatory capacity unchanged. Thus, the data collected demonstrate that freezing and thawing do not perturb the DC vaccine product maintaining over time its functional and quality characteristics.

Potentialities and Challenges of mRNA Vaccine in Cancer Immunotherapy.

Immunotherapy has become the breakthrough strategies for treatment of cancer in recent years. The application of messenger RNA in cancer immunotherapy is gaining tremendous popularity as mRNA can function as an effective vector for the delivery of therapeutic antibodies on immune targets. The high efficacy, decreased toxicity, rapid manufacturing and safe administration of mRNA vaccines have great advantages over conventional vaccines. The unprecedent success of mRNA vaccines against infection has proved its effectiveness. However, the instability and inefficient delivery of mRNA has cast a shadow on the wide application of this approach. In the past decades, modifications on mRNA structure and delivery methods have been made to solve these questions. This review summarizes recent advancements of mRNA vaccines in cancer immunotherapy and the existing challenges for its clinical application, providing insights on the future optimization of mRNA vaccines for the successful treatment of cancer.

Recent advances in cancer immunotherapy: Modulation of tumor microenvironment by Toll-like receptor ligands.

Immunotherapy is considered a promising approach for cancer treatment. An important strategy for cancer immunotherapy is the use of cancer vaccines, which have been widely used for cancer treatment. Despite the great potential of cancer vaccines for cancer treatment, their therapeutic effects in clinical settings have been limited. The main reason behind the lack of significant therapeutic outcomes for cancer vaccines is believed to be the immunosuppressive tumor microenvironment (TME). The TME counteracts the therapeutic effects of immunotherapy and provides a favorable environment for tumor growth and progression. Therefore, overcoming the immunosuppressive TME can potentially augment the therapeutic effects of cancer immunotherapy in general and therapeutic cancer vaccines in particular. Among the strategies developed for overcoming immunosuppression in TME, the use of toll-like receptor (TLR) agonists has been suggested as a promising approach to reverse immunosuppression. In this paper, we will review the application of the four most widely studied TLR agonists including agonists of TLR3, 4, 7, and 9 in cancer immunotherapy.

Virus-Mimic mRNA Vaccine for Cancer Treatment.

An effective therapeutic cancer vaccine should be empowered with the capacity to overcome the immunosuppressive tumor microenvironment. Here, the authors describe a mRNA virus‐mimicking vaccine platform that is comprised of a phospholipid bilayer encapsulated with a protein‐nucleotide core consisting of antigen‐encoding mRNA molecules, unmethylated CpG oligonucleotides and positively charged proteins. In cell culture, VLVP potently stimulated bone marrow‐derived dendritic cells (BMDCs) to express inflammatory cytokines that facilitated dendritic cell (DC) maturation and promoted antigen processing and presentation. In tumor‐bearing mice, VLVP treatment stimulated proliferation of antigen‐specific CD8+T cells in the lymphatic organs and T cell infiltration into the tumor bed, resulting in potent anti‐tumor immunity. Cytometry by time of flight (CyTOF) analysis revealed that VLVP treatment stimulated a 5‐fold increase in tumor‐associated CD8+DCs and a 4‐fold increase in tumorinfiltrated CD8+T cells, with concurrent decreases in tumor‐associated bone marrow‐derived suppressor cells and arginase 1‐ expressing suppressive DCs. Finally, CpG oligonucleotide is an essential adjuvant for vaccine activity. Inclusion of CpG not only maximized vaccine activity but also prevented PD‐1 expression in T cells, serving the dual roles as a potent adjuvant and a checkpoint blockade agent.

STING Agonist Combined to a Protein-Based Cancer Vaccine Potentiates Peripheral and Intra-Tumoral T Cell Immunity.

Combining different immunotherapy approaches is currently building the future of immunotherapy, with the view to maximize anti-tumoral efficacy for larger patient population. The KISIMA™ platform allows the development of protein-based cancer vaccines able to induce tumor-specific T cell response resulting in anti-tumoral efficacy in various mouse models. Intra-tumoral administration of stimulator of interferon gene agonists (STINGa) was shown to induce a potent inflammatory response leading to the development of tumor-specific immunity. Here, we explored the efficacy and mechanisms of action of subcutaneous STINGa treatment combined with therapeutic vaccination in various mouse tumor models. This combinatory treatment highly enhanced frequency and effector function of both peripheral and intra-tumoral antigen-specific CD8 T cells, promoting potent IFNγ and TNFα production along with increased cytotoxicity. Moreover, combination therapy favorably modulated the tumor microenvironment by dampening immune-suppressive cells and increasing CD4 T cell infiltration together with their polarization toward Th1 phenotype. Combination with STINGa treatment improved the effect of therapeutic vaccination, resulting in a prolonged control and slower growth of B16-OVA and TC-1 tumors. Altogether, the results presented here highlight the potential of combining STINGa with a therapeutic protein vaccine for cancer treatment.

Abstract PO006: Computational identification of female-biased breast cancer candidate genes correlated with tumor-infiltrating immune cell types

Abstract Biological differences between sexes are prevalent in many aspects, including in their reactions to tumor invasion. It is important to identify the prognostic biomarkers in order to better understand the interactions between the host immune system and tumors in different sexes. By examining the correlation between female-biased genes identified from The Cancer Genome Atlas (TCGA) Breast Invasive Carcinoma (BRCA) RNA-seq dataset and tumor-infiltrating immune cell types, we can better understand how female-biased genes exhibit their host immune reactions to cancer antigens. We searched for BRCA candidate genes from significant clusters reported by a recent study against published literature on sex-biased genes expressed in breast tissue, and a total list of 114 female-biased genes in BRCA was compiled. We employed TIMER2.0, a function visualization tool of tumor-infiltrating immune cells for TCGA dataset, to study the association between immune infiltration and gene expression for our selected female-biased genes in the context of CD8 T-cell and B-cell types. Both cell types give similar correlation trends. Indeed, the majority of female-biased genes (45 out of 58) show positive correlation between their expression and immune cell abundance level in both cell types, which could imply strong host immune reaction to female-biased cancer antigens. More than half of the genes (26 out of 45) showed positive correlation in both cell types for exhibiting higher expressions in tumor samples than in normal samples. Specifically, two genes, RUNX3 and CXCR6, have high positive correlation in both immune cell types and higher expressions in tumor samples than normal samples, suggesting that these genes could act as antigens on tumor cells in breast cancer. To pinpoint additional genes that are putatively involved in responding to tumor immune infiltration by CD8 T-cells and B-cells, we ran the DAVID functional annotation tool to identify enriched Gene Ontology (GO) terms and pathways for our selected 45 genes showing positive correlation in both cell types. The major GO terms in significantly enriched functional annotation clusters are “membrane,” “cell membrane,” “receptor,” “domain: SH2,” and “transcription from RNA polymerase II promoter.” The genes sharing these GO terms have been previously shown to be involved in breast cancer prognostic process (e.g. CXCR6, KIT, RUNX3) and also immune cell regulation (e.g. CD8B, DAPP1, LY75). Our result indicates that many identified female-biased genes having positive associations with CD8 T-cell and B-cell abundance levels could serve as alternative therapeutic markers which may guide researchers to develop effective cancer treatment vaccines and design immune checkpoint blockade drugs. Citation Format: Eric Li, Yongsheng Bai. Computational identification of female-biased breast cancer candidate genes correlated with tumor-infiltrating immune cell types [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2020 Oct 19-20. Philadelphia (PA): AACR; Cancer Immunol Res 2021;9(2 Suppl):Abstract nr PO006.

Immunological Mechanism and Clinical Application of PAMP Adjuvants.

The host innate immune system can recognize Pathogen-Associated Molecular Patterns (PAMPs) through Pattern Recognition Receptors (PRRs), thereby initiating innate immune responses and subsequent adaptive immune responses. PAMPs can be developed as a vaccine adjuvant for modulating and optimizing antigen-specific immune responses, especially in combating viral infections and tumor therapy. Although several PAMP adjuvants have been successfully developed they are still lacking in general, and many of them are in the preclinical exploration stage. This review summarizes the research progress and development direction of PAMP adjuvants, focusing on their immune mechanisms and clinical applications. PubMed, Scopus, and Google Scholar were screened for this information. We highlight the immune mechanisms and clinical applications of PAMP adjuvants. Because of the differences in receptor positions, specific immune cells targets, and signaling pathways, the detailed molecular mechanism and pharmacokinetic properties of one agonist cannot be fully generalized to another agonist, and each PAMP should be studied separately. In addition, combination therapy and effective integration of different adjuvants can increase the additional efficacy of innate and adaptive immune responses. The mechanisms by which PAMPs exert adjuvant functions are diverse. With continuous discovery in the future, constant adjustments should be made to build new understandings. At present, the goal of therapeutic vaccination is to induce T cells that can specifically recognize and eliminate tumor cells and establish long-term immune memory. Following immune checkpoint modulation therapy, cancer treatment vaccines may be an option worthy of clinical testing.

A Polypeptide of Tumor-Associated Antigen L6 with Intrinsic Adjuvant Activity Enhances Antitumor Immunity

Peptide vaccines are safe, and aim to elicit and expand tumor-specific immunity so as to eradicate tumors. However, achieving strong and long-lasting anti-tumor immunity with peptide vaccines for the antigen-specific treatment of cancer is challenging, in part because their efficacy depends on strong adjuvants or immunomodulators. We approached this problem by conjugating an epitope-based cancer vaccine with a lipidated sequence (an immunomodulator) to elicit a strong immune response. Lipidated and non-lipidated polyepitope proteins were generated that contained the universal T helper cell epitope (pan-DR), B cell epitopes, and the extended loop sequence of extracellular domain 2 of tumor-associated antigen L6 (TAL6). We show that the lipidated polyepitope cancer vaccine can activate bone marrow-derived dendritic cells, and trigger effective antigen-specific antibody and T helper cell responses, more effectively than the non-lipidated vaccine. Moreover, potent T cell immune responses were elicited in mice inoculated with the lipidated polyepitope cancer vaccine, providing protective antitumor immunity in mice bearing TAL6 tumors. Our study demonstrates that a lipidated polyepitope cancer vaccine could be employed to generate potent anti-tumor immune responses, including humoral and cellular immunity, which could be beneficial in the treatment of TAL6+ cancer.

A batch-effect adjusted Simon's two-stage design for cancer vaccine clinical studies.

In the development of cancer treatment vaccines, phase II clinical studies are conducted to examine the efficacy of a vaccine in order to screen out vaccines with minimal activity. Immune responses are commonly used as the primary endpoint for assessing vaccine efficacy. With respect to study design, Simon's two-stage design is a popular format for phase II cancer clinical studies because of its simplicity and ethical considerations. Nonetheless, it is not straightforward to apply Simon's two-stage design to cancer vaccine studies when performing immune assays in batches, as outcomes from multiple patients may be correlated with each other in the presence of batch effects. This violates the independence assumption of Simon's two-stage design. In this paper, we numerically explore the impact of batch effects on Simon's two-stage design, propose a batch-effect adjusted Simon's two-stage design, demonstrate the proposed design by both a simulation study and a therapeutic human papillomavirus vaccine trial, and briefly introduce a software that implements the proposeddesign.

Dendritic cell vaccine for the effective immunotherapy of breast cancer

Cancer vaccine is widely considered as a powerful tool in immunotherapy. In particular, the effective antigen processing and presentation natures of dendritic cell (DC) have made it a promising target for the development of therapeutic vaccine for cancer treatment. Here in our study, a versatile cancer cell membrane (CCM) coated calcium carbonate (CC) nanoparticles (MC) that capable of generating in situ tumor-associated antigens (TAAs) for DC vaccination is developed. Low-dose doxorubicin hydrochloride (Dox) could be encapsulated in the CC core of MC to trigger immunogenic cell death (ICD) while chlorins e6 (Ce6), a commonly adopted photosensitizer, was loaded in the CCM of MC for effective photodynamic therapy (PDT) through the generation of reactive oxygen species (ROS) to finally construct the vaccine (MC/Dox/Ce6). Most importantly, our in-depth study revealed the treatment of MC/Dox/Ce6 was able to elicit TAAs population and DC recruitment, triggering the following immune response cascade. In particular, the recruited DC cells could be stimulated in situ for effective vaccinations. Both in vitro and in vivo experiments suggested the capability of this all-in-one DDS to enhance DCs maturation to finally result in effective inhibition of both primary and distant growth of breast cancer upon single administration of low dose Dox and Ce6.

IL-6 expression promoted by Poly(I:C) in cervical cancer cells regulates cytokine expression and recruitment of macrophages.

Poly(I:C) is a promising adjuvant for cancer treatment vaccines to enhance the host anti‐tumour immune response. However, the roles of poly(I:C) in the cervical cancer microenvironment and local immune reactions are not well understood. In this study, we investigated the roles of poly(I:C) in the cervical cancer. We analysed the cytokine transcription and secretion of cervical cancer cell lines and THP‐1–derived macrophages after poly(I:C) treatment, respectively. These results revealed that IL‐6 was significantly up‐regulated, and this up‐regulation was partly dose dependent. poly(I:C)‐stimulated supernatant of cervical cancer cells promoted M1‐type cytokine IL‐1β and IL‐6 expression of THP‐1–derived macrophages, but inhibited the expression of M2‐type cytokine, IL‐10 and CCL22. The recruitment of THP‐1–derived macrophages by poly(I:C)‐stimulated cervical cancer cell supernatant was also enhanced. Inhibition of IL‐6 expression in cervical cancer cells by siRNA transfection almost completely reversed the effects of poly(I:C) treatment. Finally, we found that phosphorylation of the NF‐κB signalling pathway in cervical cancer cells occurred quickly after poly(I:C) treatment. Moreover, the NF‐κB signalling pathway inhibitor PDTC significantly inhibited poly(I:C)‐induced IL‐6 expression. Taken together, these results suggest that poly(I:C) might regulate the effects of cervical cancer cells on tumour‐infiltrated macrophages, and subsequently promote a pro‐inflammatory tumour microenvironment.

Personalized Neo-Epitope Vaccines for Cancer Treatment.

After more than a century of efforts to establish cancer immunotherapy in clinical practice, the advent of checkpoint inhibition (CPI) therapy was a critical breakthrough toward this direction (Hodi et al. in Cell Rep 13(2):412-424, 2010; Wolchok et al. in N Engl J Med 369(2):122-133, 2013; Herbst et al. in Nature 515(7528):563-567, 2014; Tumeh et al. in Nature 515(7528):568-571, 2014). Further, CPIs shifted the focus from long studied shared tumor-associated antigens to mutated ones. As cancer is caused by mutations in somatic cells, the concept to utilize these correlates of 'foreignness' to enable recognition and lysis of the cancer cell by T cell immunity seems an obvious thing to do.

Abstract 1467: Bioengineering AAV6 vector-based vaccine for cancer treatment

Abstract Introduction: Adeno-associated virus (AAV) is a small virus of the parvovirus family and is widely used in clinical-stage gene therapy because of its low toxicity and limited side effects. There are a number of naturally occurring serotypes with different tissue tropism and further engineering of the viral capsid can increase the vectors suitability for use as a cancer vaccine. We recently showed that AAV serotype 6 (AAV6) successfully delivers a transgene to dendritic cells (DC) in vitro. In the present study we analyze several rationally designed AAV6 mutants to more efficiently target DC and further increase an antigen-specific immune response. Methods: AAV6 mutants encoding ovalbumin, tyrosinase, or GFP were developed and produced in the lab by standard procedure. Vaccination was performed as a single intramuscular (i.m.) injection in C57BL/6 mice. The immune response was measured against both ovalbumin (Ova) as a model antigen and tyrosinase (Tyr) as an endogenous antigen. The Ova-specific CD8 T-cells were identified in peripheral blood and splenocytes by binding epitope-specific tetramers. Activity of antigen-specific CD8 cells was estimated by IFNy production measured by ELISpot, and by in vivo and in vitro killing assays. A humoral response was analyzed by the presence of antigen-specific antibodies in mouse serum measured by ELISA or by Western Blotting. Vaccination with GFP was used to show direct antigen expression in DC. Briefly, 3 days after i.m. injection DC from drained lymph nodes were isolated by FACS (CD11c+/MHC II+) and the presence of GFP expression was analyzed by wide-field fluorescence microscopy. Results: Several significant observations were made: (i) optimized AAV6 directly targets DC in vivo as evidenced by the presence of GFP positive DC in mouse drained lymph nodes after i.m. injection with AAV6-GFP; (ii) AAV6 vectors induced a strong immune response not only against a strong immunogen such as Ova but also against a weak endogenous antigen such as Tyr. (iii) Transgene-specific cytotoxic CD8 T- cells showed superior killing capabilities against cancer cells in vitro and in cytotoxic assay in vivo. (iv) AAV6 based vaccine generates high transgene-specific antibodies titers detectable starting 3 weeks after injection. Our data allows us to choose the AAV6 mutant with superior capacity to induce an immune response against a transgene. As a future direction we will optimize the expression cassette to directly rout an antigen into the MHC class II processing and presentation pathway which is known to dramatically increase vaccine potency. The combination of optimized AAV capsid and expression cassette will be used to confirm an ability of our vaccine approach to reduce tumor growth and extend survival in a murine tumor model. In addition, our technology is highly compatible with, and complementary to current cancer treatments, including other immunotherapy approaches such as checkpoint (PD-1/PD-L1) inhibitors. Citation Format: Karina Krotova, Andrew Day, Edward Hinchcliffe, George Aslanidi. Bioengineering AAV6 vector-based vaccine for cancer treatment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1467.