Separation of bispecific antibodies and bispecific antibody production by-products using hydroxyapatite chromatography

摘要

The present invention is directed to methods comprising the use of hydroxyapatite chromatography to separate a bispecific antibody from a solution that also comprises one or more byproducts specific to bispecific antibody production. Byproducts specific to the production of bispecific antibodies (bispecific antibody specific byproducts, “BASB”) include fragments of the bispecific antibody and heavier molecular weight variants of the antibody, wherein the fragment and/or variant comprises an Fc domain but does not exhibit affinity for the two different epitopes and/or antigens as exhibited by the desired bispecific antibody. Thus, the methods of the present invention comprise the separation of a bispecific antibody from one or more of its BASB. The hydroxyapatite chromatography methods of the invention may be used alone or may be further combined with standard purification processes and unit operations as is known in the art to achieve any level of purity of bispecific antibody necessary, e.g., for therapeutic and/or diagnostic applications.