Periodic Reporting for period 1 - DCanVAX (A novel immuno-oncolytic virus-based dendritic cell therapeutic cancer vaccine)
Reporting period: 2024-02-01 to 2025-07-31
Dendritic cells are a heterogeneous group of innate immune cells that induce adaptive immune responses to cancer. They retrieve, process and present tumour-derived antigens to naive T cells, thereby activating them. DC-based vaccines could be particularly potent via such induced systemic immune responses. Despite their potential, they have had limited clinical efficacy, in part due to the inability to sufficiently mature DC cells and difficulty selecting optimal tumour antigens. The ERC-funded DCanVAX project aims to develop a mechanism for DC maturation and activation and use a virus to lyse tumour cells ex-vivo, releasing all tumour antigens as well as markers of virus infection. It could lead to personalised DC-based vaccine generation.
The objectives of DCanVAX are to establish methods for cultivating and infecting patient-derived tumor tissue with oncolytic virus, in order to generate a highly immunogenic "oncolysate" for activating dendritic cells and loading them with the individualized tumor antigens. An additional objective is to optimize methods for generating and characterizing specific phenotypic subsets of human DCs. This will contribute towards the development of a personalized DC vaccine for the treatment of solid cancers.
The objectives of DCanVAX are to establish methods for cultivating and infecting patient-derived tumor tissue with oncolytic virus, in order to generate a highly immunogenic "oncolysate" for activating dendritic cells and loading them with the individualized tumor antigens. An additional objective is to optimize methods for generating and characterizing specific phenotypic subsets of human DCs. This will contribute towards the development of a personalized DC vaccine for the treatment of solid cancers.
As an important aim in the project, we have generated substantial preliminary data showing infectability of human hepatocellular carcinoma (HCC) cell lines, as well as other tumor cell lines, and patient-derived material with our oncolytic VSV-NDV vector. EC50 data indicate heterogeneity of susceptibility to oncolysis, although in general, all cell lines and primary tumor cells were in the range considered to be permissive and susceptible to VSV-NDV-mediated oncolysis. Furhtermore, we demonstrated that cell death via VSV-NDV infection is immunogenic in nature, as shown by analysis of established immunogenic cell death markers.
The overarching aim of the DCanVAX project was to build upon preliminary research conducted within the main ERC Starting Grant project, ONCO-VAX, where it was shown in the mouse system that VSV-NDV-based tumor oncolysates could efficiently activate dendritic cells (DCs) and load them with individualized tumor antigens, forming the basis of a broad-acting, but personalized, DC-based cancer vaccine. As a first step towards bridging this approach with a potential clinical application, we first established a method for short-term cultivation of primary tumor material obtained from clinical resections, and furthermore developed a standardized protocol for infected these patient-derived tumor cells in 2D cultures in order to generate the oncolysates needed for activating DCs. We then generated monocyte-derived DCs (moDCs) from human blood and fully characterized them, which turned out to primarily of the type-2 conventional DC (cDC2) -like phenotype. In a next step, we co-cultured these moDCs with human tumor cells that had been previously infected with VSV-NDV and performed phenotypic and functional readouts. We demonstrated that these moDCs take on an activated phenotype according to expression of known DC activation markers, such as CD80, CD86, and MHCII, by flow cytometry analysis, and preliminary data indicated that these DCs are then capable of activating CD8+ T cells in vitro. These data are fully consistent with the findings achieved in the mouse system, thereby validating the concept that ex vivo infection of patient tumor material with oncolytic VSV-NDV serves as an efficient method for generating a personalized DC-based cancer vaccine.
The overarching aim of the DCanVAX project was to build upon preliminary research conducted within the main ERC Starting Grant project, ONCO-VAX, where it was shown in the mouse system that VSV-NDV-based tumor oncolysates could efficiently activate dendritic cells (DCs) and load them with individualized tumor antigens, forming the basis of a broad-acting, but personalized, DC-based cancer vaccine. As a first step towards bridging this approach with a potential clinical application, we first established a method for short-term cultivation of primary tumor material obtained from clinical resections, and furthermore developed a standardized protocol for infected these patient-derived tumor cells in 2D cultures in order to generate the oncolysates needed for activating DCs. We then generated monocyte-derived DCs (moDCs) from human blood and fully characterized them, which turned out to primarily of the type-2 conventional DC (cDC2) -like phenotype. In a next step, we co-cultured these moDCs with human tumor cells that had been previously infected with VSV-NDV and performed phenotypic and functional readouts. We demonstrated that these moDCs take on an activated phenotype according to expression of known DC activation markers, such as CD80, CD86, and MHCII, by flow cytometry analysis, and preliminary data indicated that these DCs are then capable of activating CD8+ T cells in vitro. These data are fully consistent with the findings achieved in the mouse system, thereby validating the concept that ex vivo infection of patient tumor material with oncolytic VSV-NDV serves as an efficient method for generating a personalized DC-based cancer vaccine.
The results generated within this action form the basis of a proof of concept supporting the proposed approach as a novel cancer vaccine. Although this work provided a proof of concept that the approach is effective for the cDC2 phenotype, we would ultimate aim to generate a robust and reliable system for generating human DCs of the cross-presenting cDC1 subtype. As current immunotherapy approaches remain largely ineffective in the majority of solid tumor entities, this work represents and import step forward towards developing a revolutionary approach that could advance the current state of the art, bring major real-world impact, and improve the lives of cancer patients globally.
As a next step towards clinical development of the approach, and in order to further refine the methodology and eventual clinical product, in follow-on work, we aim to develop a method of generating cDC1s by differentiation of induced pluripotent stem cells (iPSCs). These methods have previously been reported, and we will establish then and further optimize these protocols for our purpose. We will then subject these iPSC-derived cDC1 cells to the VSV-NDV-oncolysate-based procedure developed within DCanVAX and characterize their quality and function as a further improvement on our DC vaccine approach.
From a commercialization perspective, several important further development steps are needed. First, additional proof-of-concept data will be necessary to convincingly support the further development towards clinical testing and in order to justify the acquisition of additional funds in order to carry out this work. Additional regulatory advice is additionally needed in order to understand the guidelines and considerations that will need to be undertaken for the further development of the approach into a drug product. We are already working with a globally-recognized expert in regulatory affairs, and he and his team will continue to provide consultancy and aid us in preparation for scientific advice/pre-IND meetings with the regulatory authorities in the U.S. and Europe.
Additionally, an invention disclosure has already been made through the Technical University of Munich in order to ensure protection of the intellectual property and support commercialization of the approach. We currently keep the option open to in-license the IP to the PI's startup, Fusix Biotech, which is development oncoltic virus-based cancer immunotherapies. Licensing and partnering opportunities with other relevant biotech and pharma companies will also be pursued in order to identify the best option for the further preclinical, and later, clinical development of the DCanVAX technology.
As a next step towards clinical development of the approach, and in order to further refine the methodology and eventual clinical product, in follow-on work, we aim to develop a method of generating cDC1s by differentiation of induced pluripotent stem cells (iPSCs). These methods have previously been reported, and we will establish then and further optimize these protocols for our purpose. We will then subject these iPSC-derived cDC1 cells to the VSV-NDV-oncolysate-based procedure developed within DCanVAX and characterize their quality and function as a further improvement on our DC vaccine approach.
From a commercialization perspective, several important further development steps are needed. First, additional proof-of-concept data will be necessary to convincingly support the further development towards clinical testing and in order to justify the acquisition of additional funds in order to carry out this work. Additional regulatory advice is additionally needed in order to understand the guidelines and considerations that will need to be undertaken for the further development of the approach into a drug product. We are already working with a globally-recognized expert in regulatory affairs, and he and his team will continue to provide consultancy and aid us in preparation for scientific advice/pre-IND meetings with the regulatory authorities in the U.S. and Europe.
Additionally, an invention disclosure has already been made through the Technical University of Munich in order to ensure protection of the intellectual property and support commercialization of the approach. We currently keep the option open to in-license the IP to the PI's startup, Fusix Biotech, which is development oncoltic virus-based cancer immunotherapies. Licensing and partnering opportunities with other relevant biotech and pharma companies will also be pursued in order to identify the best option for the further preclinical, and later, clinical development of the DCanVAX technology.