The present invention concerns methods and compositions for forming anti-cancer vaccine complexes. In preferred embodiments, the anti-cancer vaccine complex comprises an antibody moiety that binds to dendritic cells, such as an anti-CD74 antibody or antigen-binding fragment thereof, attached to an AD (anchoring domain) moiety and a xenoantigen, such as CD20, attached to a DDD (dimerization and docking domain) moiety, wherein two copies of the DDD moiety form a dimer that binds to the AD moiety, resulting in the formation of the vaccine complex. The anti-cancer vaccine complex is capable of inducing an immune response against xenoantigen expressing cancer cells, such as CD138negCD20+ MM stem cells, and inducing apoptosis of and inhibiting the growth of or eliminating the cancer cells.
