Stable pharmaceutical formulation

A method of producing a stable liquid pharmaceutical formulation comprising the steps of:

• (a) preparing 5-25 mM succinate buffer having a pH 5.5 to 6.5;
• (b) adding 50 mg/ml of a fusion protein in which an extracellular ligand-binding domain of a human p75 tumor necrosis factor receptor is fused to an Fc domain of human IgG to said buffer of step (a) to form a buffer/protein mixture;
• and
• (c) adding 120 to 160 mM of sodium chloride to said buffer/protein mixture of step (b) in order to form said stable liquid pharmaceutical formulation, wherein the formulation is free of a stabilizer, an amino acid, an ammonium salt, a saccharide, polysorbate, poloxamer, a polymer, or a mixture thereof.