Glioblastoma is the most aggressive
primary brain tumor with an unmet need for more effective
therapies. Here, we investigated combination
therapies based on L19TNF, an antibody-
cytokine fusion
protein based on
tumor necrosis factor that selectively localizes to
cancer neovasculature. Using immunocompetent orthotopic
glioma mouse models, we identified strong anti-
glioma activity of L19TNF in combination with the
alkylating agent CCNU, which cured the majority of
tumor-bearing mice, whereas monotherapies only had limited efficacy. In situ and ex vivo immunophenotypic and molecular profiling in the mouse models revealed that L19TNF and
CCNU induced
tumor DNA damage and treatment-associated
tumor necrosis. In addition, this combination also up-regulated
tumor endothelial cell adhesion molecules, promoted the infiltration of immune cells into the
tumor, induced immunostimulatory pathways, and decreased immunosuppression pathways. MHC immunopeptidomics demonstrated that L19TNF and
CCNU increased antigen presentation on
MHC class I molecules. The antitumor activity was T cell dependent and completely abrogated in immunodeficient mouse models. On the basis of these encouraging results, we translated this treatment combination to patients with
glioblastoma. The clinical translation is ongoing but already shows objective responses in three of five patients in the first recurrent
glioblastoma patient cohort treated with L19TNF in combination with
CCNU (NCT04573192).