Therapeutic macromolecules (e.g., antibodies) must be formulated in a manner that not only makes the molecules suitable for administration to patients, but also maintains their stability during storage. For example, therapeutic antibodies in liquid solution are prone to degradation, aggregation and/or undesired chemical modifications unless the solution is formulated properly. The stability of an antibody in liquid formulation depends not only on the kinds of excipients used in the formulation, but also on the amounts and proportions of the excipients relative to one another. Furthermore, other considerations aside from stability must be taken into account when preparing a liquid antibody formulation. Examples of such additional considerations include the viscosity of the solution and the concentration of antibody that can be accommodated by a given formulation. Thus, when formulating a therapeutic antibody, great care must be taken to arrive at a formulation that remains stable, contains an adequate concentration of antibody, and possesses a suitable viscosity as well as other properties which enable the formulation to be conveniently administered to patients.
Antibodies to the human interleukin-6 receptor (hIL-6R) are one example of a therapeutically relevant macromolecule that requires proper formulation. Anti-hIL-6R antibodies are clinically useful for the treatment and/or prevention of diseases such as rheumatoid arthritis, ankylosing spondylitis, and other conditions. Exemplary anti-IL-6R antibodies are described, inter alia, in U.S. Pat. Nos. 7,582,298; 6,410,691; 5,817,790; 5,795,695; and 6,670,373. A particularly important anti-hIL-6R antibody with great therapeutic potential is the antibody referred to in U.S. Pat. No. 7,582,298 as VQ8F11-21 (also referred to herein as “mAb1”).
Although anti-hIL-6R antibodies are known, there remains a need in the art for novel pharmaceutical formulations comprising anti-hIL-6R antibodies which are sufficiently stable and also suitable for administration to patients.