HK1251237B - Method for promoting efficiency of purification of fc region-containing polypeptide - Google Patents

Description

Method for improving purification efficiency of polypeptide containing FC region

Technical Field

The present invention relates to a method for increasing the dynamic binding ability of an Fc region-containing polypeptide to a protein a resin in protein a column chromatography, a purification method using such a method, and the like.

Background

In the production of antibody drugs, purification steps using protein a columns, ion exchange columns, and the like greatly affect the production efficiency (yield) of antibodies; therefore, it is desirable to increase the efficiency of these steps. The means for achieving efficiency include the following two methods: (1) increasing the binding capacity per unit volume of resin; and (2) reducing the time required for purification by high flow processing.

Recently, improvement of protein a resin has been developed, and more antibodies can bind to protein a resin, and thus effective antibody purification is achieved. For example, as a typical first-generation protein A resin, the binding capacity of a general antibody to rProtein A sepharose Fast Flow manufactured by GE Healthcare is 15 to 20g/L resin; whereas the Mab Select SuRe, the second generation Protein a resin produced by the same company, is currently the most commonly used in the world, with a binding capacity of about 30g/L resin generally observed. In addition, the latter can accommodate linear flow rates about 1.5 to 2 times higher than the former resin, and more efficient protein a purification of antibody molecules has become possible.

Bispecific antibodies have the property of recognizing two different types of antigens, and therefore they carry two types of H chains. Therefore, the culture supernatant containing the bispecific antibody contains not only the bispecific antibody containing 2H chains but also an antibody containing only 1H chain. In order to isolate these antibodies from bispecific antibodies, fc region variants having modified binding activity to protein a resin have been used (patent documents 1 and 2). There is a fear that such molecular modification may have an effect of reducing the efficiency of protein a purification of the bispecific antibody.

In this case, new methods for more efficient purification of bispecific antibodies using protein a resin columns are needed.

CITATION LIST

[ patent document ]

[ patent document 1] US20100331527

[ patent document 2] US20130018174

Disclosure of Invention

[ problem to be solved by the invention ]

The object of the present invention is to provide a method for efficiently purifying Fc region-containing polypeptides, particularly bispecific antibodies, using a protein a resin column.

[ means for solving problems ]

As a result of intensive studies to solve the above problems, the present inventors have found that the dynamic binding ability of an antibody is improved and the purification efficiency of the antibody is improved by preparing an Fc region whose first polypeptide chain and second polypeptide chain have different binding activities to a protein a resin from each other, thereby completing the present invention.

Specifically, the present invention provides the following:

[1] a method of increasing the dynamic binding capacity of a polypeptide comprising an Fc region of a protein a resin in protein a column chromatography;

[2] the method of [1], comprising the steps of: a step of preparing a first polypeptide chain and a second polypeptide chain having different binding activities to the resin as an Fc region;

[3] the method of [1] or [2], which comprises the steps of: preparing a first polypeptide chain as an Fc region bound to a resin, preparing a second polypeptide chain which does not bind to the resin or exhibits weaker binding to the resin than the first polypeptide chain, and as an Fc region;

[4] the method according to any one of [1] to [3], which comprises the step of modifying the Fc region of the Fc-region-containing polypeptide such that a first polypeptide chain of the Fc region binds to the resin and a second polypeptide chain of the Fc region does not bind to the resin or shows weak binding to the resin compared to the first polypeptide chain;

[5] the method of any one of [1] to [4], wherein the first polypeptide chain of the Fc region comprises CH3 of IgG1, igG2, or IgG4, and the second polypeptide chain of the Fc region comprises CH3 of IgG 3;

[6] the method according to any one of [1] to [5], wherein the amino acid at position 435 in the EU numbering of the first polypeptide chain of the Fc region is His, and the amino acid at position 435 in the EU numbering of the second polypeptide chain of the Fc region is Arg;

[7] the method according to any one of [1] to [6], wherein the increase in binding ability is 5g/L or more of resin;

[8] the method according to any one of [1] to [7], wherein the dynamic binding ability after the increase is 45g/L resin or more;

[9] the method according to any one of [1] to [8], wherein the Fc region-containing polypeptide is an antibody;

[10] the method of [9], wherein the antibody is a bispecific antibody;

[11] a method for purifying an Fc region-containing polypeptide using the method according to any one of [1] to [10 ];

[12] an Fc region-containing polypeptide purified by the method of [11 ];

[13] a protein a resin bound by a polypeptide comprising an Fc region, wherein the dynamic binding capacity of the Fc region-containing polypeptide to the protein a resin in protein a column chromatography is 45g/L resin or more;

[14] a polypeptide comprising an Fc region, wherein the dynamic binding capacity of the protein a resin is increased in protein a column chromatography;

[15] a method of making an Fc region-containing polypeptide using a protein a resin, comprising the steps of:

(a) Preparing a first polypeptide chain and a second polypeptide chain of an Fc region having different binding activities to the resin from each other;

(b) Comparing the dynamic binding capacity of the Fc region-containing polypeptide of step (a) to a protein a resin in a protein a column chromatography with the dynamic binding capacity of an Fc region-containing polypeptide comprising two polypeptide chains having substantially the same binding activity to said resin in a protein a column chromatography;

(c) Contacting a sample comprising a polypeptide comprising a first polypeptide chain comprising an Fc region and a polypeptide comprising a second polypeptide chain comprising an Fc region with the resin; and

(d) Collecting an Fc region-containing polypeptide bound to the resin and comprising a heterologous polypeptide comprising a first polypeptide chain comprising an Fc region and a polypeptide comprising a second polypeptide chain comprising an Fc region;

[16] [15] wherein the step (a) is to prepare a first polypeptide chain as an Fc region which binds to the resin, and prepare a second polypeptide chain as an Fc region which does not bind to the resin or shows weaker binding to the resin as compared with the first polypeptide chain;

[17] the method of [15] or [16], wherein the step (a) is to modify the Fc region of the Fc region-containing polypeptide for purification such that a first polypeptide chain of the Fc region binds to the resin and a second polypeptide chain of the Fc region does not bind to the resin or shows weaker binding to the resin compared to the first polypeptide chain;

[18] the method of any one of [15] to [17], wherein the sample in step (c) comprises a polypeptide of the common L chain capable of providing binding capacity to both a polypeptide of the first polypeptide chain comprising an Fc region and a polypeptide of the second polypeptide chain comprising an Fc region;

[19] [11] the purification method according to, wherein the Fc region-containing polypeptide is an antibody;

[20] [19] the purification method of [19], wherein the antibody is a bispecific antibody;

[21] an antibody purified by the method of [19 ];

[22] the bispecific antibody purified by the method of [20 ]; and

[23] a column containing the resin of [13 ].

[ Effect of the invention ]

The present invention provides a method for more efficiently purifying Fc region-containing polypeptides, particularly bispecific antibodies, using protein a resins.

Brief description of the drawings

Fig. 1 shows a breakthrough curve chromatogram for the detection of proteins expelled from the column when the BiAb solution was continuously loaded onto the protein a resin column.

Modes for carrying out the invention

The present invention will be described in detail below.

The Fc region-containing polypeptides used in the present invention may contain antibody Fc regions, which include polypeptides formed by fusing an Fc region to another polypeptide (e.g., an antibody).

"Polypeptides" of the present invention generally refer to peptides and proteins of about 10 amino acids or longer. In addition, they are generally polypeptides from organisms, but are not particularly limited, and for example, they may be polypeptides comprising artificially designed sequences. Further, they may be any of naturally occurring polypeptides, synthetic polypeptides, recombinant polypeptides and the like.

"Fc region" generally refers to a region comprising two polypeptide chains consisting of a hinge portion or a portion thereof, a CH2 domain and a CH3 domain in an antibody molecule, but is not particularly limited thereto, and there are cases where the hinge portion or a portion thereof is not included. The human IgG-like Fc region refers to, for example, a region from cysteine position 226 to C-terminus, or from proline at position 230 to C-terminus, according to EU numbering of Kabat, but is not limited thereto. Further, the human CH2 domain refers to positions 231 to 340 according to EU numbering of Kabat, and the human CH3 domain refers to positions 341 to 447 according to EU numbering of Kabat, but is not limited thereto.

The Fc region can be preferably obtained by partially digesting IgG1, igG2, igG3, monoclonal antibody containing Fc region, etc. with a protease such as pepsin, and then eluting the fraction adsorbed on the protein A resin again. The protease is not particularly limited as long as it can digest a full-length antibody to produce Fab and F (ab') 2 in a limited manner by appropriately setting enzyme reaction conditions such as pH, and examples include pepsin and papain.

Examples of Fc regions include human IgG-type Fc, and they may be, for example, any of IgG1, igG2, igG3, and IgG4 isotypes.

The Fc region of the present invention comprises the first and second polypeptide chains described above.

One embodiment of the invention is a method of increasing the dynamic binding capacity of an Fc region-containing polypeptide to a protein a resin in a protein a column chromatography. The first polypeptide chain and the second polypeptide chain comprised in the Fc region preferably have different binding activities to the protein a resin from each other. For example, when a polypeptide chain that binds to a protein a resin is used as the first polypeptide chain, a polypeptide chain that does not bind to protein a or binds weakly to the first polypeptide chain as compared to the first polypeptide chain can be used as the second polypeptide chain. As the first polypeptide chain, a polypeptide chain comprising CH3 of IgG1, igG2 or IgG4 can be used, and as the second polypeptide chain, a polypeptide chain comprising CH3 of IgG3 can be used. In this case, igG1, igG2, igG3 and IgG4 may be naturally occurring, or they may include mutations within a range that allows the object of the present invention to be achieved. Furthermore, as the first polypeptide chain, a polypeptide chain whose position 435 according to EU numbering is His (H) can be used. As second polypeptide chain, a polypeptide chain having Arg (R) at position 435 according to EU numbering may be used. In addition, polypeptide chains at positions 435 and 436 according to EU numbering are His (H) and Tyr (Y), respectively, can be used as the first polypeptide chain. Polypeptide chains in which positions 435 and 436 according to EU numbering are Arg (R) and Phe (F), respectively, can be used as second polypeptide chain. Positions other than positions 435 or 436 according to EU numbering may be the same as or different from those of naturally occurring IgG.

In this embodiment, increasing the dynamic binding capacity of the Fc region-containing polypeptide to the resin in protein a column chromatography can be accomplished by modifying the Fc region of the Fc region-containing polypeptide that binds to the resin such that the binding activities of the first polypeptide chain of the Fc region and the second polypeptide chain of the Fc region to the resin will be different from each other.

In another embodiment of the invention, increasing the dynamic binding capacity of an Fc region-containing polypeptide to a resin in a protein a column chromatography can be accomplished by modifying the Fc region of the Fc region-containing polypeptide that binds to the resin such that a first polypeptide chain of the Fc region binds to the resin, but a second polypeptide chain of the Fc region does not bind to the resin or exhibits weaker binding to the resin as compared to the first polypeptide chain.

Examples of modifications include, but are not limited to, modifications made so that the first and second polypeptide chains of the Fc region will comprise a CH3 region as described above, e.g., modifications made so as to comprise the particular amino acids described above at the specified positions.

On the other hand, the region other than the Fc region in the Fc region-containing polypeptide used in the present invention may be in a homologous form or a heterologous form.

The homologous form has 1 or 2 or more homogeneous or identical antigen binding activities (i.e., when the Fc region-containing polypeptide is an antigen binding molecule, it refers to an antigen binding molecule having 1 or 2 or more homogeneous or identical antigen binding activities, such as an IgG-type antibody having two identical antigen binding sites).

The heterologous form preferably has a different antigen binding activity (i.e., the Fc region-containing polypeptide is a bispecific antigen binding molecule, e.g., a bispecific antibody). When the Fc region-containing polypeptide used in the present invention is a bispecific antibody, the L chain may be a common L chain, although the H chain may be heterologous, and the common L chain preferably provides binding capability for both H chains. When the bispecific antibody is an IgG-type antibody, it consists of two heterologous H chains and two identical common L chains.

Binding capacity includes Static Binding Capacity (SBC) and Dynamic Binding Capacity (DBC). Static binding capacity refers to the upper limit of the amount of polypeptide that the resin can adsorb, and dynamic binding capacity refers to the extent to which the polypeptide can be collected when a solution containing the polypeptide flows through the column. The resin having a large dynamic binding ability can efficiently adsorb a polypeptide even at a high linear flow rate, and can complete the purification of the polypeptide in a short time.

For example, the Dynamic Binding Capacity (DBC) can be determined by the following method. First, a column loaded with a resin is set in a chromatography device, and a sample solution containing a polypeptide is caused to flow through the column at a prescribed linear flow rate. Then, the absorbance of the eluate is measured, and when the Breakthrough (BT) of a specific ratio (e.g., 5%) of the absorbance of the added sample solution is measured, the DBC is determined by identifying the mass of the added polypeptide.

The following devices and the like may be used for DBC calculation:

an LC device: AKTA AVANT25 manufactured by GE Healthcare

Software: unicorn version 6.1 manufactured by GE Healthcare

Protein a resin: mab Select SuRe (Cat No. 17-5438-05) or Hitrap Mab Select SuRe (Cat No. 11-0034-93) manufactured by GE Healthcare

Buffer solution:

Balanced/Primary Wash-20 mmol/L sodium phosphate, pH7.5

Elution-50 mmol/L acetic acid

Regenerated-0.1 mol/L NaOH

The method of calculating the DBC may be performed as follows.

Using the above apparatus, software and resin, and performing a chromatographic procedure by the following procedure, DBC was calculated. The calculation method using 5% BT as an index is shown below.

(1) The OD of 100% leakage (= 100% BT) was confirmed by passing the loaded fraction (IgG concentration: P g/L) through the LC device without passing through the column _280nm The value of (c). This value is denoted a.

(2) Defining the value obtained by multiplying 0.05 by a as OD in 5% BT _280nm . The value is denoted b _5％ 。

(3) Allowing the load fraction to continuously flow through a quantity of equilibrated resin (r L) when OD is reached _280nm Value up to b _5％ At this time, the volume of the loaded fraction is read from the chromatogram. The value is denoted c _5％ L.

(4) By the equation (P x c) _5％ ) The value obtained by/r is calculated as DBC _5％ It is the dynamic binding capacity at 5% BT.

DBC _5％ ＝(P x c _5％ ) R (unit: g/L resin)

In determining DBC _10％ C can be determined in a similar manner _10％ To perform the calculation.

In one embodiment of the present invention, when 5% BT is used as the standard, the increase in dynamic binding ability of the Fc region-containing polypeptide of the protein A resin in the protein A column chromatography is at least 5g/L of resin, preferably 10g/L of resin or more, 15g/L of resin or more, 20g/L of resin or more, and 25g/L of resin or more.

In one embodiment of the present invention, the increase in dynamic binding ability of the Fc region-containing polypeptide of the protein A resin in protein A column chromatography is at least 5g/L resin, preferably 10g/L resin or more, 15g/L resin or more, 20g/L resin or more and 25g/L resin or more, at a contact time of 3.4 minutes when 5% BT is used as a standard.

In one embodiment of the present invention, the dynamic binding capacity of the Fc region-containing polypeptide for protein A resin in protein A column chromatography, when 5% BT is used as a standard, is at least 45g/L resin or more, preferably 50g/L resin or more, 55g/L resin or more, and 60g/L resin or more, according to the method of the present invention.

In one embodiment of the invention, the dynamic binding capacity of the Fc region-containing polypeptide of the protein a resin in protein a column chromatography is at least 50g/L resin or more, preferably 51g/L resin or more, 52g/L resin or more, 53g/L resin or more, 54g/L resin or more and 55g/L resin or more, at a contact time of 3.4 minutes, using 5% BT as a standard according to the methods of the invention.

In one embodiment of the present invention, the Fc region-containing polypeptide may be a polypeptide in which the Fc region is linked to another protein, biologically active peptide, or the like. Examples of other proteins and bioactive peptides include, but are not limited to, receptors, adhesion molecules, ligands (cytokines, chemokines, etc.) and enzymes. They may be coagulation factors such as FIX, FIXa and FX.

In one embodiment of the invention, the Fc region-containing polypeptide may be an immunoadhesin.

In another embodiment of the invention, the Fc region-containing polypeptide may be an antibody. The antibodies of the present invention are not particularly limited as long as they bind to the antigen of interest, and they may be polyclonal or monoclonal antibodies. Monoclonal antibodies are preferred because they can be stably produced as homogeneous antibodies.

The monoclonal antibodies used in the present invention include not only those derived from animals such as human, mouse, rat, hamster, rabbit, sheep, camel and monkey, but also artificially modified gene recombinant antibodies such as chimeric antibodies, humanized antibodies (also referred to as reshaped human antibodies) and bispecific antibodies. In addition, they also include genetically recombinant antibodies produced by artificially modifying antibody constant regions and the like to change the physical properties of antibody molecules, particularly the isoelectric point (pI), modify the affinity for Fc receptors, and the like, for the purpose of improving retention in blood and in vivo kinetics.

The immunoglobulin class of the antibody used in the present invention is not particularly limited, and the class may be any class including IgG, such as IgG1, igG2, igG3 and IgG4, igA, igD, igE and IgM. However, igG is preferred.

The antibody used in the present invention includes not only whole antibodies but also antibody fragments such as Fv, fab and F (ab) 2 and minibodies (low molecular weight antibodies), for example monovalent or divalent or higher single chain Fv, which are formed by linking antibody variable regions via a linker such as a peptide linker (scFv, sc (Fv) 2, diabodies such as scFv dimer and the like).

The above-described antibodies for use in the present invention can be prepared by methods well known to those skilled in the art.

Basically, hybridomas producing monoclonal antibodies can be prepared using known techniques as described below. Specifically, immunization is carried out according to a conventional immunization method using cells expressing a desired antigen of the desired antigen as a sensitizing antigen. The resulting immune cells are fused to known parent cells by conventional cell fusion methods. Monoclonal antibody-producing cells (hybridomas) are screened from the fused cells by a conventional screening method to produce hybridomas. Hybridomas can be produced, for example, according to the method of Milstein et al (Kohler, G.and Milstein, C., methods enzymol. (1981) 73.

Amino acid residues may be modified by modifying one or more bases in the DNA encoding the polypeptide and expressing the DNA in a host cell, as described below. The number, position and type of nucleotides to be modified can be easily determined by those skilled in the art according to the type of amino acid residue after modification.

In the present invention, "modification" means substitution, deletion, addition, insertion or a combination thereof.

In addition to the amino acid sequence modifications described above, the antibodies used in the present invention may also include additional changes. Additional modifications may be selected from any amino acid substitution, deletion, and modification, or combinations thereof. Specifically, polypeptides containing the following modifications in their amino acid sequence are included in the present invention:

amino acid modifications to increase the heterologous binding rate of the two H chains of the bispecific antibody;

amino acid modifications to stabilize disulfide bonds formed between a first polypeptide having antigen binding activity and a second polypeptide with or without antigen binding activity;

amino acid modifications for improving antibody retention in plasma;

modifications that improve stability under acidic conditions;

modifications to reduce heterogeneity;

a modification which inhibits deamidation;

a modification that introduces a difference in isoelectric point between the two polypeptides; and

modifications that alter affinity for Fc γ receptors.

Methods for obtaining human antibodies are also known. For example, a desired human antibody having antigen binding activity can be obtained by sensitizing human lymphocytes in vitro with an antigen of interest or cells expressing an antigen of interest; and fusing the sensitized lymphocyte and the human myeloma cell to obtain the compound. Alternatively, a desired human antibody can also be obtained by immunizing a transgenic animal having a complete human antibody gene bank with an antigen. In addition, techniques for obtaining human antibodies by panning using human antibody libraries are known. For example, phage display can be used to express the variable regions of human antibodies as single chain antibodies (scfvs) on the phage surface, and then the phage that binds the antigen can be selected to obtain human antibodies. Antibodies for use in the present invention also include such human antibodies.

When the antibody gene is isolated and introduced into an appropriate host to produce an antibody, the host and the expression vector may be used in an appropriate combination. When eukaryotic cells are used as the host, animal cells, plant cells and fungal cells can be used. The animal cells include mammalian cells such as CHO, COS, myeloma, baby Hamster Kidney (BHK), heLa and Vero cells. The antibody can be obtained by introducing the gene of the antibody of interest into these cells by transformation, and then culturing the transformed cells in vitro.

The antigen of the antibody used in the present invention is not particularly limited, and it may be any antigen. Examples of the antigen preferably include ligands (cytokines, chemokines, etc.), receptors, cancer antigens, MHC antigens, differentiation antigens, immunoglobulins and immune complexes partially containing immunoglobulins. Examples include coagulation factors such as FIX, FIXa and FX.

To collect the expression product, the medium is collected as the polypeptide is secreted into the medium. When the polypeptide is produced intracellularly, the cells are lysed and the polypeptide is then collected.

The polypeptide can be collected and purified from the recombinant cell culture by using known methods, including ammonium sulfate or ethanol precipitation, acid extraction, anion or cation exchange chromatography, phosphocellulose chromatography, hydrophobic interaction chromatography, affinity chromatography, hydroxylapatite chromatography and lectin chromatography. In the present invention, protein a affinity chromatography is preferred. Here, a purification method using a column, a separation method using a column, and chromatography may be used synonymously. Examples of columns using protein A resins include POROS A (manufactured by Applied Biosystems), rProtein A Sepharose F.F (manufactured by GE), proSep vA (manufactured by Millipore), but are not limited thereto.

In addition, ligand-bound resins produced by modifying the amino acid sequence of intact protein A and the like can be used for protein A affinity chromatography. When such modified protein a resins are used, the amino acid modifications of the invention result in differences in binding activity, and the polypeptide multimers of interest can be isolated and purified. Examples of the modified protein a-binding resin include mabSelect SuRE (manufactured by GE Healthcare) and Hitrap mabSelect SuRE (manufactured by GE Healthcare), but are not limited thereto. Here, a column packed with protein a resin, a column using protein a resin, a protein a resin column, and a protein a column are synonymous. In addition, a purification method using a protein a resin and a purification method using a protein a column can also be used synonymously.

One embodiment of the present invention is a method for purifying an Fc region-containing polypeptide using a method for increasing the dynamic binding ability of an Fc region-containing polypeptide to a protein a resin in protein a column chromatography. More specifically, one embodiment is a method for purifying an antibody, and another embodiment is a method for purifying a bispecific antibody.

Another embodiment of the present invention is a polypeptide containing an Fc region purified by the above purification method. More specifically, one embodiment is an antibody purified by the above purification method, and another embodiment is a bispecific antibody purified by the above purification method.

In addition, another embodiment of the present invention is a protein A resin to which an Fc region-containing polypeptide binds at 45g/L resin or more based on 5% BT, and a column containing the resin. The dynamic binding ability of the Fc region-containing polypeptide to the resin and the resin-containing column is preferably 50g/L resin or more, 55g/L resin or more, 60g/L resin or more and 65g/L resin or more when 5% BT is used as a standard.

Further, a specific embodiment of the present invention is an Fc region-containing polypeptide-bound protein A resin, wherein the dynamic binding ability of the Fc region-containing polypeptide to the protein A resin and a resin-containing column in protein A column chromatography is 50g/L resin or more at a contact time of 3.4 minutes, when 5% BT is taken as a standard. The dynamic binding ability of the Fc region-containing polypeptide to the resin and the resin-containing column is preferably 51g/L resin or more, 52g/L resin or more, 53g/L resin or more, 54g/L resin or more, and 55g/L resin or more, based on 5% BT as a standard, at a contact time of 3.4 minutes.

One embodiment of the invention is a polypeptide comprising an Fc region that has increased dynamic binding capacity to a protein a resin in protein a column chromatography. More specifically, in one embodiment, the Fc region-containing polypeptide is an antibody, and in another embodiment, the Fc region-containing polypeptide is a bispecific antibody.

In one embodiment of the present invention, the increase in dynamic binding capacity of the Fc region-containing polypeptide of the protein A-containing resin in protein A column chromatography is at least 5g/L resin, preferably 10g/L resin or more, 15g/L resin or more, 20g/L resin or more and 25g/L resin or more, when 5% BT is used as a standard.

In one embodiment of the present invention, the increase in dynamic binding capacity of the Fc region-containing polypeptide of the protein A resin in protein A column chromatography is at least 5g/L, preferably 10g/L or more, 15g/L or more, 20g/L or more, and 25g/L or more of the resin at a contact time of 3.4 minutes, when 5% BT is used as a standard.

Among the Fc region-containing polypeptides having increased dynamic binding ability to protein a resin in protein a column chromatography, it is preferable that the first polypeptide chain and the second polypeptide chain contained in the Fc region have different binding activities to the protein a resin. For example, when a polypeptide chain that binds to a protein a resin is used as the first polypeptide chain, a polypeptide chain that does not bind to the protein a resin or binds weakly to the protein a resin can be used as the second polypeptide chain as compared to the first polypeptide chain. As the first polypeptide chain, a polypeptide chain comprising CH3 of IgG1, igG2 or IgG4 can be used. As the second polypeptide chain, a polypeptide chain comprising CH3 of IgG3 can be used. In this case, naturally occurring IgG1, igG2, igG3 and IgG4 may be used, or they may contain mutations within a range that allows the object of the present invention to be achieved. Furthermore, as the first polypeptide chain, a polypeptide chain of which position 435 according to EU numbering is His (H) can be used. As second polypeptide chain, a polypeptide chain having Arg (R) at position 435 according to EU numbering may be used. In addition, polypeptide chains at positions 435 and 436 according to EU numbering are His (H) and Tyr (Y), respectively, can be used as the first polypeptide chain. Polypeptide chains in which positions 435 and 436 according to EU numbering are Arg (R) and Phe (F), respectively, can be used as second polypeptide chain. Positions other than positions 435 or 436 according to EU numbering may be the same as those of naturally occurring IgG or may be different from those of naturally occurring IgG.

One embodiment of the present invention is a method for producing an Fc region-containing polypeptide using a protein a resin, comprising the steps of:

(a) Preparing a first polypeptide chain and a second polypeptide chain of an Fc region, the first polypeptide chain and the second polypeptide chain having different binding activities to a resin from each other;

(b) Comparing the dynamic binding capacity of the Fc region-containing polypeptide of step (a) to the protein a resin in the protein a column chromatography with the dynamic binding capacity of the Fc region-containing polypeptide comprising two polypeptide chains having substantially the same binding activity to the protein a resin in the protein a column chromatography;

(c) Contacting a sample comprising a polypeptide comprising a first polypeptide chain comprising an Fc region and a polypeptide comprising a second polypeptide chain comprising an Fc region with a resin; and

(d) Collecting a polypeptide comprising an Fc region comprising a heterologous polypeptide comprising a first polypeptide chain comprising an Fc region and a polypeptide comprising a second polypeptide chain comprising an Fc region.

The above step (a) may be a step of preparing a first polypeptide chain as an Fc region, which binds to a resin, and a second polypeptide chain as an Fc region, which does not bind to the resin or shows weak binding to the resin (compared to the above binding of the first polypeptide chain to the resin). Further, the above step (a) may be a step of modifying the Fc region of the Fc region-containing polypeptide targeted for purification so that the first polypeptide chain of the Fc region binds to the resin, but the second polypeptide chain of the Fc region does not bind to the resin or shows weaker binding to the resin (as compared to the binding of the above first polypeptide chain to the resin). The modification is not particularly limited as long as it is a modification for obtaining an Fc region having the above-described characteristics, and examples include modification of a first polypeptide chain into a polypeptide chain comprising CH3 of IgG1, igG2 or IgG4, and modification of a second polypeptide chain into a polypeptide chain comprising CH3 of IgG 3. Examples of such modifications include modification of position 435 in the first polypeptide chain to His according to EU numbering and modification of position 435 in the second polypeptide chain to Arg according to EU numbering. Examples of other modifications include modification of positions 435 and 436 of the first polypeptide chain to His (H) and Tyr (Y), respectively, according to EU numbering, and modification of positions 435 and 436 of the second polypeptide chain to Arg (R) and Phe (F), according to EU numbering. Positions other than positions 435 or 436 according to EU numbering may be the same as or different from those of naturally occurring IgG.

In the above step (b), the two polypeptide chains may be any polypeptide chain as long as their binding activity to the resin is substantially the same, and homology between the two polypeptide chains may be high or low. For example, a "Fc region-containing polypeptide comprising two polypeptide chains having substantially the same binding activity to the resin" is a polypeptide comprising an Fc region comprising two first polypeptide chains or a polypeptide comprising an Fc region comprising two second polypeptide chains. Further, examples of two polypeptide chains having substantially the same binding activity to protein a resin include: two polypeptide chains, which are polypeptide chains each comprising any CH3 of IgG1, igG2 or IgG 4; two polypeptide chains, which are polypeptide chains each comprising CH3 of IgG 3; two polypeptide chains, wherein position 435, according to EU numbering, in the polypeptide chains is both His (H) or both Arg (R); two polypeptide chains, which are both polypeptide chains, wherein positions 435 and 436 according to EU numbering are His (H) and Tyr (Y), respectively; two polypeptide chains, which are both polypeptide chains, wherein positions 435 and 436 according to EU numbering are Arg (R) and Phe (F), respectively.

"substantially the same" means not necessarily exactly the same as long as it is within a range in which the object of the present invention can be achieved, and means including "the same".

In one embodiment of the present invention, the "comparing" in the above step (b) may be a step of "confirming the dynamic binding ability of the Fc region-containing polypeptide of step (a) to the increase of the protein a resin in the protein a column chromatography" compared with the dynamic binding ability of the Fc region-containing polypeptide comprising two polypeptide chains having substantially the same binding activity to the resin in the protein a column chromatography.

By comparing or confirming the dynamic binding ability, the maximum amount of antibody that can be loaded on the protein a resin column when producing the antibody can be known, and this enables efficient production of the antibody.

The sample described in step (c) above may comprise two different L-chain polypeptides or a common L-chain polypeptide, which may provide binding capacity to the H-chain of a polypeptide of the first polypeptide chain comprising an Fc region and the H-chain of a polypeptide of the second polypeptide chain comprising an Fc region.

In one embodiment of the present invention, the Fc region-containing polypeptide is an antibody in the above-described method for purifying an Fc region-containing polypeptide, and in another embodiment, the Fc region-containing polypeptide is a bispecific antibody.

The above-described steps (a) to (d) are not necessarily performed in this order, and each step may be included a plurality of times.

One embodiment of the present invention is a method for purifying an Fc region-containing polypeptide using a protein a resin, comprising the above steps (a) to (d).

All patents and references cited explicitly herein are incorporated by reference in their entirety.

The present invention will be further illustrated by the following examples, but the technical scope of the present invention should not be construed as being limited thereto.

Examples

EXAMPLE 1 preparation of antibody Gene expression vectors and expression of Each antibody

In the examples, an anti-FIXa/FX bispecific antibody (H1 chain/H2 chain/L chain: SEQ ID NO: 1/2/3) having a functional activity of replacing FVIII as described in WO2012/067176 (hereinafter, this is referred to as "BiAb", which is a so-called heterologous antibody) was used. The BiAb comprises four strands consisting of three strands. The four chains consist of an H1 chain and an H2 chain (these two chains are two types of H chains), and two identical L chains (which are one type of L chain). The antibody is obtained by the method described in WO 2012/067176. The antibody gene is inserted into an animal cell expression vector. Bispecific antibodies were expressed by transfecting CHO cells with the vector. In addition, "Q homo" comprising two L chains and two H1 chains, and "J homo" comprising two L chains and two H2 chains were obtained by the above-described method.

The antibody is of the IgG4 type, with the substitution of Arg for His at position 435 according to EU numbering in the Fc region of the H1 chain. This substitution reduces or eliminates the binding activity of the Fc region to the protein a resin.

Example 2 method for evaluating Dynamic Binding Capacity (DBC)

In general, DBC is described by tracing the behavior of consecutively loaded proteins being expelled from a chromatography column as a breakthrough curve in a chromatogram (hereinafter referred to as "BTC") by UV monitoring using a purification device connected to a UV detector. As an example, a BTC chromatogram when using BiAb is shown in fig. 1.

DBC was assessed by comparing the loading of 5% breakthrough points (BT points) in antibody molecules and their mixtures.

The following devices and the like are used for DBC calculation:

an LC device: AKTA AVANT25 manufactured by GE Healthcare

Software: unicorn version 6.1 manufactured by GE Healthcare

Protein a resin: mab Select SuRe (Cat No. 17-5438-05) or Hitrap Mab Select SuRe (Cat No. 11-0034-93) manufactured by GE Healthcare

Buffer solution:

balanced/preliminary washing-20 mmol/L sodium phosphate, pH7.5

Elution-50 mmol/L acetic acid

Regenerated-0.1 mol/L NaOH

The method of calculating DBC proceeds as follows.

DBC was calculated using the above-described apparatus, software and resin, and by performing a chromatographic operation as follows.

(1) Allowing the loaded fraction (IgG concentration: pg/L) at one time to flow through the LC device without passing through the column, and confirming the OD of 100% leakage (= 100% BT) _280nm The value of (c). This value is denoted a.

(2) The value obtained by multiplying 0.05 by a was defined as OD in 5% BT _280nm . The value is denoted b _5％ 。

(3) The load fraction was continuously flowed through a set amount of equilibration resin (r L) as OD _280nm A value of b _5％ At this time, the volume of the loaded fraction is read from the chromatogram. The value is denoted c _5％ L。

(4) By the equation (P x c) _5％ ) The value obtained for/r is calculated as DBC _5％ It is the dynamic binding capacity at 5% BT.

DBC ₅ ％＝(P x c _5％ ) R (unit: g/L resin)

When DBC is determined _10％ By determining c in the same manner _10％ To perform the calculation.

EXAMPLE 3 DBC of each antibody molecule alone

DBC of each of Q homo, J homo and BiAb was determined under the following conditions:

column: hitrap MabSelect Sure (hereinafter MSS) (GE Healthcare),

0.7X 2.5cm

Loading materials: the material actually loaded with CM in IgG concentration, pH and conductivity was simulated using each purified antibody standard.

IgG concentration: about 2g/L; pH7.5; conductivity: 1.2S/m.

J homo with a purity of about 80%, Q homo with a purity of about 85% and BiAb with a purity of about 95%.

Contact time: 3.4 minutes (43.75 cm/h)

The results are shown in Table 1.

[ Table 1]

The results show that the DBC of BiAb is significantly higher than that of J homo and Q homo.

EXAMPLE 4 DBC validation of pH and contact time for BiAb

Next, DBC of BiAb alone was confirmed when the pH of the loading solution and the contact time on the resin were changed, and the effects of two parameters were confirmed. The conditions are as follows:

column: mabSelect Sure (GE Healthcare), 1.0x 20 cm

Loading material: diluted formulations of purified CM-mimicked BiAb standards (BiAb: 95%): 2g/L; pH6.5-8.0 (verified); conductivity: 1.2S/m

Contact time: 3-8 minutes (verify)

The results are shown in table 2.

[ Table 2]

Example 5 DBC in a mixture of BiAb and Homo

In the culture supernatant actually loaded onto the protein a resin (hereinafter referred to as "HCCF"), biAb, J homo and Q homo were present as a mixture. More specifically, from the viewpoint of recovering BiAb as a substance of interest, J homo and Q homo can be considered as substances competing with BiAb. Therefore, it is meaningful to verify the DBC of BiAb in the presence of certain amounts of J homo and Q homo in HCCF when considering actual production. For verification, the experiment was performed under the following conditions:

column: hitrap MabSelect Sure (MSS) (GE Healthcare), 0.7x 2.5cm

Loading material: mixture of purified BiAb and Homo standard mimicking CM:

2g/L；pH 7.5；Cond：1.2S/m

control BiAb (95%) J homo: biAb: q homo = 5: 95:0

Mimic A J homo：BiAb：Q homo＝10：83∶7

Mimic B J homo：BiAb：Q homo＝10：68：22

Contact time: 3.4 minutes (43.75 cm/h)

The loading of BTC was split and the BiAb/Homo ratio per BT point was confirmed by analytical ciec.

The conditions for analysis of CIEC were as follows:

HPLC apparatus: alliance 2695/2487 manufactured by Waters

Software: empower3 manufactured by Waters

CIEC column: proPac WCX-10 manufactured by Thermo scientific, product No.054993

Column temperature: 30 deg.C

Injection amount: 30 g/injection

Buffer solution:

mobile phase A-9.6mmol/L Tris,6.0mmol/L piperazine, 11.0mmol/L imidazole, pH6.0

Mobile phase B-9.6mmol/L Tris,6.0mmol/L piperazine, 11.0mmol/L imidazole, 150mmol/L NaCl, pH 10.1

Gradient conditions:

the results are shown in Table 3

[ Table 3]

From the above results, the following were found.

·DBC：J homo≈Q homo＜BiAb

Affinity to MSS: q homo < BiAb < J homo

Effect of parameters on BiAb DBC:

pH: in the pH range of 6.5-8.0, lower pH tends to produce higher DBC, but the effect is minimal.

Contact time: in the range of 3 to 8 minutes, the DBC was not lower than that of Q homo and J homo even at 3 minutes, although longer contact times tended to produce higher DBC.

The results reflect the characteristics of the present invention with respect to affinity to MSS, and are shown by the order of leakage in example 5

On the other hand, with respect to DBC, it is presumed that the difference in affinity with MSS resin and availability of ligand produce the result. More specifically, since J homo has two sequences that strongly bind to the MSS ligand, it binds to the MSS resin at two sites. That is, the MSS ligands present in the region occupied by J homo cannot be used. On the other hand, since BiAb has only one site having a sequence that strongly binds to MSS, its spatial degree of freedom is higher than J homo, and high DBC can be achieved by effectively using more MSS ligands. The reason why Q homo has low DBC is only that the binding activity of the whole molecule is low. Furthermore, Q homo and J homo are believed to competitively inhibit the binding of BiAb to MSS.

Claims (7)

1. A method for increasing the dynamic binding ability of an Fc-region containing polypeptide to a protein a resin in protein a column chromatography, comprising the step of preparing a first polypeptide chain and a second polypeptide chain as first and second polypeptide chains of an Fc-region, said first and second polypeptide chains having different binding activities to each other than said resin, wherein the Fc-region is an Fc-region of IgG4 isotype, wherein the amino acid at position 435 in the first polypeptide chain of the Fc-region according to EU numbering is His and the amino acid at position 435 in the second polypeptide chain of the Fc-region according to EU numbering is Arg.

2. The method of claim 1, wherein the increase in binding capacity is 5g/L resin or more.

3. The method of claim 1, wherein the dynamic binding capacity after the increase is 45g/L resin or more.

4. The method of claim 1, wherein the Fc region-containing polypeptide is an antibody.

5. The method of claim 4, wherein the antibody is a bispecific antibody.

6. A method of purifying an Fc region-containing polypeptide using the method of any one of claims 1 to 5.

7. A method of making an Fc region-containing polypeptide using a protein a resin, comprising the steps of:

(a) Preparing a first polypeptide chain and a second polypeptide chain of an Fc region having different binding activities to the resin from each other, wherein the Fc region is of an IgG4 isotype, wherein the amino acid at position 435 in the first polypeptide chain of the Fc region according to EU numbering is His, and the amino acid at position 435 in the second polypeptide chain of the Fc region according to EU numbering is Arg;

(b) Comparing the dynamic binding capacity of the Fc region-containing polypeptide of step (a) to a protein a resin in protein a column chromatography with the dynamic binding capacity of an Fc region-containing polypeptide comprising two polypeptide chains with the same binding activity to said resin in protein a column chromatography;

(c) Contacting a sample comprising a polypeptide comprising a first polypeptide chain comprising an Fc region and a polypeptide comprising a second polypeptide chain comprising an Fc region with the resin; and

(d) Collecting an Fc region-containing polypeptide bound to the resin and comprising a heterologous polypeptide comprising a first polypeptide chain comprising an Fc region and a polypeptide comprising a second polypeptide chain comprising an Fc region.