JP-7857274-B2 - multispecific molecules

Inventors

• アンソニー・サイモン・ロバーツ
• ジョージ・コプシダス
• マイケル・ロス・ルーク
• フィル・アンソニー・ジェニングス

Assignees

• イミュネクサス・セラピューティクス・リミテッド

Dates

Publication Date

20260512

Application Date

20231226

Priority Date

20160226

Claims (15)

1. A multispecific molecule capable of binding to two or more different target antigens or target epitopes, (i) A first target antigen or target epitope-binding domain molecule (BDM) comprising a V-like domain (VLD) scaffold having three exposed binding loops (BLs) contained therein, wherein at least two of the three BLs are modified or substituted with respect to their corresponding native sequences within the scaffold so as to selectively bind to a heterogeneous target antigen or target epitope, (ii) comprising an antibody or its antigen-binding fragment or a pharmacologically active protein or peptide which is a non-antibody protein or peptide that binds to a second target antigen or target epitope, Herein, the molecule wherein at least one BDM is bound via its N-terminus to the C-terminus of a polypeptide present within the pharmacologically active protein or peptide.
2. The molecule according to claim 1, wherein (i) an antibody heavy chain polypeptide and/or an antibody light chain polypeptide and/or all antibody heavy chain polypeptides and antibody light chain polypeptides, or (ii) at least one BDM is bound to the C-terminus of each polypeptide chain of a non-antibody protein or polypeptide.
3. The molecule according to claim 1 or 2, wherein the pharmacologically active protein is a full-length antibody.
4. The molecule according to claim 2, wherein the ratio of antibody chain to BDM is 4: 2n , where n is a number from 1 to 5.
5. The molecule according to any one of claims 1 to 4, wherein the pharmacologically active protein is an antigen-binding fragment selected from the group consisting of Fab, Fab', F(ab') 2 , or chemically bound F(ab') 2 .
6. The molecule according to any one of claims 1 to 5, wherein at least one BDM is bound to the C-terminus of the CH1 domain, CH2 domain, or CH3 domain of the heavy chain polypeptide.
7. (i) The first target antigen and the second target antigen are different, or (ii) The first target epitope and the second target epitope are on the same antigen or different antigens. The molecule according to any one of claims 1 to 6.
8. The molecule according to any one of claims 1 to 7, wherein the molecule comprises one or two pairs of BDM, wherein the BDM in the pair are identical.
9. The aforementioned VLD scaffolding is The molecule according to claim 1, comprising a framework sequence corresponding to residues 1-25, 34-54, 60-97, and 106-126 of Sequence ID No. 1 described above.
10. The aforementioned BDM is (Sequence No. 5) Includes or consists of the sequence described above, Here, X is any amino acid residue, n1 , n2 , and n3 are numbers , where 1 , 2, and 3 refer to BL1, BL2, and BL3, respectively. The molecule according to any one of claims 1 to 9, wherein Xn 1 is 5 to 8 amino acids, Xn 2 is 5 to 8 amino acids, and Xn 3 is 10 to 15 amino acids.
11. (i) Xn 1 has 8 amino acids, (ii)Xn 2 has 5 amino acids, and (iii)Xn 3 has 10 to 15 amino acids. The molecule according to claim 10.
12. The molecule according to claim 1, wherein the binding of the at least one BDM to the pharmacologically active protein or peptide is by linker means, direct fusion , or covalent bond .
13. The molecule according to claim 12, wherein the linker is a Gly-Ser peptide linker.
14. A pharmaceutical composition comprising a molecule according to any one of claims 1 to 13 , together with a pharmacokinetically acceptable carrier and/or additive.
15. The composition according to claim 14 for use in the manufacture of pharmaceuticals.

Description

This disclosure relates to a multispecific molecule capable of simultaneously binding to at least two different target antigens or target epitopes. The molecule comprises at least one binding domain molecule (BDM) that binds to a first target antigen or target epitope, such BDM being modified to selectively bind to a heterologous target and conjugated to a pharmacologically active protein or peptide, which is an antibody or its antigen-binding fragment or a non-antibody protein or peptide, that binds to a second target antigen or target epitope, and these BDMs are conjugated to the C-terminus of a polypeptide present within the pharmacologically active protein or peptide. Incorporation by Reference: All materials cited or referenced herein, and all materials cited or referenced in materials cited herein, together with any manufacturer's instructions, statements, product specifications, and product sheets relating to any product mentioned herein or in any documents incorporated herein by reference, are incorporated herein by reference in their entirety. This application claims priority to Australian Patent Applications No. 2016900708 and 2016900709, the entire contents of which are incorporated herein by reference. Sequence Listing References: The entire contents of electronically submitted sequence listings are incorporated by reference for all purposes. Numerous recombinant proteins have been developed as therapeutic agents. However, unmodified proteins are known to be rapidly removed in the body by renal filtration, cell clearance mechanisms in the reticuloendothelial system, or proteolysis (Francis (1992) Focus on Growth Factors 3:4-11). Various modifications of proteins and peptides have been developed to enhance the stability, circulation time, and biological activity of therapeutic proteins (see Francis (1992) Focus on Growth Factors 3:4-10). However, mechanisms that allow such therapeutic proteins to persist in the body for longer periods are needed in this field. Therapeutic monoclonal antibodies and antibody-related products, such as antibody-fusion proteins, antibody fragments, and antibody-drug conjugates (hereinafter collectively referred to as antibody products), have grown to become a major product class within the biopharmaceutical market. Today, antibody products are approved for the treatment of various diseases, including, to name a few, certain cancers, multiple sclerosis, asthma, and rheumatoid arthritis. Despite the unparalleled successes in antibody drug development in recent years, the lack of efficacy against specific target diseases necessitates the exploration of new strategies for developing more effective antibody drugs. One method used to improve antibody efficacy is to create bispecific antibody-like protein structures that bind to two targets simultaneously. Conventional antibodies can only bind to one specific target (i.e., they have one specificity). Bispecific antibodies are generally engineered proteins composed of two different antibodies or antibody-like fragments (known as antibody-like scaffolds) fused together so that such bispecific antibodies can simultaneously bind to two different targets (i.e., they have two specificities). Most antibody-like scaffolds are generally constructed from antibody fragments or made from antibody-like proteins that can bind to specific targets like antibodies. Bispecific antibodies enable more potent antibody drugs that can be designed to induce and activate immune effector cells such as T cells to specifically kill tumors, bind to multiple targets and act on multiple pathogenic pathways, bind to multiple sites on a single target cell or target protein to enhance specificity or induce synergistic induction, and target tumors with heterogeneous properties. Currently, a key distinguishing factor among existing technologies used to produce bispecific antibody products is the general method of fusing various antibody-like scaffolds together. This type of bispecific antibody product has several significant drawbacks. First, small bispecific antibody products created by fusing two or more antibody-like scaffolds generally fall well below the renal threshold and typically have very short circulating half-lives, ranging from a few minutes to a few hours. Such short half-lives necessitate daily or continuous infusion, which can exceed the drug's toxicity threshold. Second, many antibody-like scaffolds are insufficient due to their monovalent nature, meaning they have only one antigen-binding site compared to antibodies with two. Complete antibodies, however, can bind to either antigen-binding site, improving overall binding strength (known as the avidity effect) and offering certain advantages compared to monovalent antibody-like scaffolds. Currently, there are only a handful of methods for producing bispecific antibody products in whole-IgG format. Generally, these methods artificially create an antibody skeleton that combines two different par