A soluble multimeric polypeptide or protein is disclosed that is able to inhibit interaction of leukocyte Fcy receptors (Fc?R) and immunoglobulin G (IgG). The protein or polypeptide comprises two or more Fc binding regions linked in a head to tail arrangement, at least one of which is derived from an Fc?R type receptor, and an Fc domain of an immunoglobulin which has been modified to reduce or prevent binding to the said Fc binding regions and/ or to alter effector function. Also described are polynucleotide molecules encoding the polypeptide or protein and the use thereof in methods of treating a subject for an immune- complex (IC)-mediated inflammatory disease.
