Stabilized liquid interleukin-2 containing pharmaceutical compositions are provided. The compositions comprise an amino acid base, which serves as the primary stabilizing agent of the polypeptide, and an acid and/or its salt form to buffer the solution within an acceptable pH range for stability of the interleukin-2. The compositions are near isotonic. Methods for increasing stability of interleukin-2 in a liquid pharmaceutical composition and for increasing storage stability of such a pharmaceutical composition are also provided.
