The present invention provides sustained release and long acting forms of peptide therapeutic, particularly Interleukin-1 receptor antagonist (IL-1ra), including multimeric forms of IL-1ra, including variants of IL-1ra which are capable of multimerising, and compositions comprising the long acting and multimeric forms of IL-1ra, and a process of preparation thereof. The present invention also provides compositions comprising the multimeric forms of IL-1ra, including IL-1raK, KIL-1ra and KIL-1raK, which are effective in inhibiting, treating and/or ameliorating rheumatoid disease, inflammatory diseases or disorders, autoinflammatory disorders or conditions resulting from adverse effects of Interleukin-1 (IL-1). Methods of treating a subject comprising administering the composition comprising the multimeric forms of IL-1ra are also provided.
