The present invention relates to an active (immunostimulatory) composition comprising at least one RNA, preferably an mRNA, encoding at least two (preferably different) antigens capable of eliciting an (adaptive) immune response in a mammal wherein the antigens are selected from the group consisting of PSA (Prostate-Specific Antigen), PSMA (Prostate-Specific Membrane Antigen), PSCA (Prostate Stem Cell Antigen), and STEAP (Six Transmembrane Epithelial Antigen of the Prostate). The invention furthermore relates to a vaccine comprising said active (immunostimulatory) composition, and to the use of said active (immunostimulatory) composition (for the preparation of a vaccine) and/or of the vaccine for eliciting an (adaptive) immune response for the treatment of prostate cancer (PCa), preferably of neoadjuvant and/or hormone-refractory prostate cancers, and diseases or disorders related thereto. Finally, the invention relates to kits, particularly to kits of parts, containing the active (immunostimulatory) composition and/or the vaccine.
