The present invention relates to the use of a filamentous bacteriophage that does not display (i) a mammalian cell internalization signal (ii) an α-synuclein antigen or α-synuclein antibody or (iii) a β-amyloid antigen or β-amyloid antibody, either alone or in combination with a filamentous bacteriophage which displays an antibody that specifically binds to a pro-inflammatory cytokine, to treat Parkinsons disease.