The invention relates to a combination medicament for use in the therapy of a malignant neoplastic disease, comprising an IL-12 polypeptide, or a nucleic acid expression vector encoding said IL-12 polypeptide, and a non-agonist ligand, particularly an antibody, capable of binding to one of PD-1, PD-L1 or PD-L2, with a dissociation constant of at least 10 -7 M -1 . The non-agonist ligand is provided as a dosage form for systemic delivery, and the IL-12 polypeptide, or said nucleic acid expression vector, is provided by administration into a tumour, into the vicinity of a tumour, or to the lymph node associated with a tumour.
