The present invention generally relates to novel protease-activatable T cell activating bispecific molecules and idiotype-specific polypeptides. The present invention also relates to polynucleotides encoding such protease-activatable T cell activating bispecific molecules and idiotype-specific polypeptides, and vectors and host cells comprising such polynucleotides. The invention further relates to methods for producing the protease-activatable T cell activating bispecific molecules and idiotype-specific polypeptides of the invention, and to methods of using these protease-activatable T cell activating bispecific molecules and idiotype-specific polypeptides in the treatment of disease.