Abstract: Mesenchymal stem cells (MSCs) for use in the treatment of a tumor, wherein said treatment comprises the combined administration of said mesenchymal stem cells with an anti-tumor immunotherapy, and wherein said MSCs do not comprise exogenous nucleic acids that encode immune response-stimulating cytokines. In a preferred embodiment the invention relates to the use of said MSCs in the treatment of a tumor and/or malignant disease, wherein the anti-tumor immunotherapy for combined administration comprises the administration of a cellular immunotherapy, preferably chimeric antigen receptor (CAR) T cells, wherein said T cell receptor binds specifically to a tumor-associated antigen, and the mesenchymal stem cells are not genetically modified.

Abstract: A tumor or a malignant disease can be treated by the combined administration of mesenchymal stem cells (MSCs) with an anti-tumor immunotherapy. The MSCs need not be genetically modified, and do not include exogenous nucleic acids that encode immune response-stimulating cytokines. The anti-tumor immunotherapy can be a cellular immunotherapy, such as administration of chimeric antigen receptor (CAR) T cells, in which the T cell receptor binds specifically to a tumor-associated antigen.