A humanised agonistic antibody which binds human PD-1 comprising a heavy chain wherein the variable domain of the heavy chain comprises the sequence given in SEQ ID NO:1 for CDR-H1, the sequence given in SEQ ID NO: 2 for CDR-H2 and the sequence given in SEQ ID NO: 3 for CDR-H3 and the heavy chain framework region is derived from human sub-group sequence VH4 3-1 4-30.4+JH4 (SEQ ID NO: 33). The disclosure also extends to therapeutic uses of the antibody molecules, compositions and methods for producing said antibody molecules.