At the 2025 Annual Meeting of the Croatian Immunological Society, held in Njivice on September 22–23, the first results of establishing an ex vivo/in vitro model for testing the efficacy of oncolytic viral preparations were presented. A short presentation demonstrated the oncolytic potential of vaccine strains of Newcastle disease virus (NDV) and mumps virus (MuV) in various cultures of primary canine tumor tissues obtained by surgical excision, as well as in continuous cell lines of human breast carcinoma and canine mammary carcinoma. Both viruses were shown to act as potent oncolytic agents in 2D and 3D cell culture systems of all tested cell types. Infected cells exhibited clear signs of disintegration and programmed cell death. These initial findings represent an important step toward the development of novel therapeutic strategies for hard-to-treat cancers in both species. In a separate communication, results were presented on the development of ex tempore oncolytic viral preparations based on mumps virus and vesicular stomatitis virus. Protocols were established for the reproducible production of sterile, high-titre infectious viral preparations, as well as validated methods for characterization of the active substance (virus) and other formulation components (matrix). The resulting preparations are ready for safety and efficacy testing in animal models. ex vivo/in vitro models for testing the efficacy of oncolytic viral preparations. A short presentation presents the results of the oncolytic potential of vaccine strains of Newcastle disease virus (NDV) and mumps virus (MuV) in different cultures of primary canine tumor tissue obtained by surgical extraction, as well as in continuous cell lines of human breast cancer and canine mammary carcinoma. We have shown that both viruses act as potent tumor cytolytic agents in 2D and 3D cell cultures of all the above cell types, and that infected cells clearly show signs of lysis and programmed cell death. These initial findings represent an important step towards the development of new therapeutic strategies for difficult-to-treat cancers in both species.
A separate press release also presents the results of work on the development of ex tempore oncolytic viral preparations of mumps virus and vesicular stomatitis virus. Protocols for the reproducible production of sterile preparations of high concentrations of infectious virus have been developed, as well as qualified methods for the characterization of the active substance (virus) and other ingredients (matrix). The preparations are ready for testing of safety and efficacy in animals.