The invention aims to provide an immunoglobulin-binding protein having improved chemical stability, especially stability against alkali. The object can be achieved by improving stability against alkali by substituting an amino acid residue(s) at a particular position(s) in an immunoglobulin-binding domain such as domain C of protein A derived from a bacterium belonging to the genus Staphylococcus, to another/other particular amino acid residue(s).

There is disclosed a relatively simple method to increase the performance of surface localised multi-valent affinity ligands whose target's isoelectric pH differs significantly from the ligand's optimal target-binding pH. This situation can result in ligand binding of target affecting local pH and subsequent binding of more target. Increasing the buffering capacity of the ligand via recombinant or other addition of charge groups to the ligand is expected to partially offset such effects, leading to enhanced binding capacity as well as possible secondary favourable alterations in regard to ligand elution pH, and non-specific surface binding of non-target proteins.

The present invention relates to a novel polypeptide affinity ligand coupled to solid supports and affinity purification of IgG antibodies. The invention is comprised of (1) the design, generation, and purification of polypeptide ligands, (2) coupling of a polypeptide affinity ligand to a solid support matrix, (3) purification of IgG (polyclonal and monoclonal antibodies), and (4) cleaning and reuse of polypeptide supported solid matrix.

The invention relates to a method of isolating an immunoglobulin, comprising the steps of: a) providing a separation matrix comprising multimers of immunoglobulin-binding alkali-stabilized Protein A domains covalently coupled to a porous support, b) contacting a liquid sample comprising an immunoglobulin with the separation matrix, c) washing said separation matrix with a washing liquid, d) eluting the immunoglobulin from the separation matrix with an elution liquid, and e) cleaning the separation matrix with a cleaning liquid,
wherein the alkali-stabilized Protein A domains comprise mutants of a parental Fc-binding domain of Staphylococcus Protein A (SpA), as defined by SEQ ID NO: 51 or SEQ ID NO: 52, wherein the amino acid residues at positions 13 and 44 of SEQ ID NO: 51 or 52 are asparagines and wherein at least the asparagine residue at position 3 of SEQ ID NO: 51 or 52 has been mutated to an amino acid selected from the group consisting of glutamic acid, lysine, tyrosine, threonine, phenylalanine, leucine, isoleucine, tryptophan, methionine, valine, alanine, histidine and arginine.

Provided herein are methods of separating host cell lipases from an anti-LAG3 antibody or antigen binding fragment in chromatographic processes and methods of improving polysorbate-80 stability in an anti-LAG3 antibody formulation by separating host cell lipases from the anti-LAG3 antibody or antigen binding fragment using chromatographic processes. Also provided are pharmaceutical compositions comprising an anti-LAG3 antibody or antigen binding fragment and less than 2 ppm of a host cell lipase.

Provided herein are methods of separating host cell lipases from an anti-LAG3 antibody or antigen binding fragment in chromatographic processes and methods of improving polysorbate-80 stability in an anti-LAG3 antibody formulation by separating host cell lipases from the anti-LAG3 antibody or antigen binding fragment using chromatographic processes. Also provided are pharmaceutical compositions comprising an anti-LAG3 antibody or antigen binding fragment and less than 2 ppm of a host cell lipase.

The invention relates to a Protein A chromatography step of a purification process for a therapeutic protein, wherein a load solution including the therapeutic protein is applied onto a Protein A chromatography medium. According to the invention, a solution comprising CaCl.sub.2 is used as a wash solution for the Protein A chromatography medium for enhancing the removal of lipases, in particular phospholipase B-like 2 (PLBL2). The invention is of particular interest for the purification of CHO-expressed antibodies, such as tanezumab.

In a method for facilitating selection of chromatography parameters for manufacturing a therapeutic protein, one or more process parameter values associated with a hypothetical chromatography process, and one or more molecular descriptors descriptive of the therapeutic protein, are received. The method also includes predicting a performance indicator for the hypothetical chromatography process at least by analyzing the one or more process parameters and the one or more molecular descriptors using a machine learning model. The machine learning model is a regression tree model, an extreme gradient boost model, or an elastic net model. The method also includes causing the predicted performance indicator, and/or an indication of whether the predicted performance indicator satisfies one or more acceptability criteria, to be presented to a user via a user interface.

Provided herein are, inter alia, biological manufacturing and downstream purification processes.

Disclosed is a method for efficiently separating and purifying recombinant human coagulate factor VIII Fc fusion protein. The method comprises steps of affinity chromatography and anion exchange chromatography; and the sample captured by means of the affinity chromatography is eluted with a salt ion buffer containing 5%-20% polyol organic solvents under the condition of pH 4.0 to 8.0, and the protein sample can be separated and purified to 85% or more by further ProteinA affinity chromatography. The purification method is simple to operate, naturally connects each step of chromatography, has a high recovery rate and low cost, and easily increases production.