阅读说明：本技术 新型抗cd3抗体 (Novel anti-CD 3 antibodies ) 是由 迪·贡德 克里斯蒂安·赫斯 塞巴斯蒂安·迈耶 亚历山大·西莫南 泰笛·贝尔特拉梅蒂 大卫· 于 2018-06-04 设计创作，主要内容包括：本发明涉及对人CD3特别是对CD3ε结构域特异的新型抗体。(The present invention relates to novel antibodies specific for human CD3, in particular for the CD3 epsilon domain.)

1. An antibody or functional fragment thereof specific for human CD3 comprising:

(a) (ii) a variable light chain,

wherein the variable light chain comprises, from N-terminus to C-terminus, the region LFW1-LCDR1-LFW2-LCDR2-LFW3-LCDR3-LFW4, wherein each LFW represents a light chain framework region and each LCDR represents a light chain complementarity determining region, wherein the LCDR1 is as set forth in SEQ ID NO: 1 is shown in the specification; the LCDR2 is shown as SEQ ID NO: 2 is shown in the specification; and said LCDR3 is as set forth in SEQ ID NO: 3 is shown in the specification; and

(b) the variable heavy chain is a heavy chain variable,

wherein the variable heavy chain comprises, from N-terminus to C-terminus, the regions HFW1-HCDR1-HFW2-HCDR2-HFW3-HCDR3-HFW4, wherein each HFW represents a heavy chain framework region and each HCDR represents a heavy chain complementarity determining region, wherein the HCDR1 is as set forth in SEQ ID NO: 5 is shown in the specification; the HCDR2 is shown as SEQ ID NO: 6 is shown in the specification; and the HCDR3 is as shown in SEQ ID No: shown at 7.

2. The antibody or functional fragment thereof of claim 1, wherein said variable light chain is a vk 1 light chain, and/or wherein said variable heavy chain is a VH3 chain.

3. The antibody or functional fragment thereof according to claim 1 or claim 2, wherein the variable light chain is identical to a light chain according to SEQ ID NO: 4, and/or wherein the variable heavy chain has at least 90% sequence identity to an amino acid sequence according to SEQ ID NO: 8 has at least 90% sequence identity.

4. The antibody or functional fragment thereof of any one of claims 1-3, wherein the variable light chain comprises an arginine or lysine, preferably an arginine, at position 54 of the light chain amino acid according to AHo numbering.

5. The antibody or functional fragment thereof according to any one of claims 3-4, wherein the variable light chain comprises the amino acid sequence of SEQ ID NO: 4, and the variable heavy chain comprises the amino acid sequence of SEQ id no: 8.

6. The antibody or functional fragment thereof of any one of claims 1-5, wherein the antibody or functional fragment thereof is characterized by one or more of the following parameters:

(i) k binding to human CD3_DA value of less than 40nM, in particular less than 10nM, more in particular less than 6nM, in particular as measured by surface plasmon resonance;

(ii) k binding to human CD3_DA value of less than 20nM, in particular less than 10nM, more in particular less than 5nM, in particular as measured by surface plasmon resonance; and

(iii) when expressed as an scFv antibody, the mean midpoint of the thermal unfolding temperature (Tm) exceeds at least 60 ℃, particularly at least 65 ℃, more particularly at least 68 ℃ as determined by differential scanning fluorimetry.

7. A multispecific polypeptide comprising the antibody or functional fragment thereof of any one of claims 1-6.

8. A pharmaceutical composition comprising an antibody or functional fragment thereof according to any one of claims 1-6 or a multispecific polypeptide according to claim 7, and a pharmaceutically acceptable carrier and/or excipient.

9. An antibody or functional fragment thereof according to any one of claims 1-6 or a multispecific polypeptide according to claim 7 or a composition according to claim 8 for use as a medicament.

10. Use of an antibody or functional fragment thereof according to any one of claims 1-6 or a multispecific polypeptide according to claim 7 or a composition according to claim 8 in the manufacture of a medicament.

11. A nucleic acid sequence or collection of nucleic acid sequences encoding the antibody or functional fragment thereof according to any one of claims 1-6.

12. A vector or collection of vectors comprising a nucleic acid sequence or collection of nucleic acid sequences according to claim 11.

13. A method for producing an antibody or functional fragment thereof according to any one of claims 1-6, comprising the step of expressing a nucleic acid sequence or a collection of nucleic acid sequences according to claim 11, or a vector or collection of vectors according to claim 12.

14. A method of generating a multispecific construct comprising the steps of:

(a) in one or more steps, one or more nucleic acid sequences encoding the antibody or functional fragment thereof according to any one of claims 1-6 are cloned into a multispecific construct comprising a nucleic acid sequence encoding at least a second binding domain or fragment thereof, and optionally one or more additional binding domains or fragments thereof.

15. The method of claim 14, wherein the second binding domain is a second antibody or a functional fragment thereof.

Technical Field

The present invention relates to novel antibodies specific for human CD3, in particular for the CD3 epsilon domain.

Background

The present invention relates to novel anti-CD 3 antibodies, in particular antibodies directed to the CD3 epsilon domain, in particular novel antibodies with improved specificity and cross-reactivity properties, which bind with high affinity and high potency.

T cell receptors or TCRs are molecules found on the surface of T lymphocytes (or T cells) that are responsible for recognizing antigens bound to Major Histocompatibility Complex (MHC) molecules on the surface of Antigen Presenting Cells (APCs). The binding between the TCR and the antigen has a relatively low affinity. When the TCR binds to antigen and MHC, T lymphocytes are activated by a series of biochemical events mediated by associated enzymes, co-receptors, specialized accessory molecules, and activated or released transcription factors.

TCRs are associated with other molecules such as CD3, CD3 has three distinct chains (γ, δ, and ε) in mammals, and has a δ 2(CD247) chain or a δ/ε chain. These accessory molecules have transmembrane domains and are critical for the transmission of signals from the TCR into the cell; the cytoplasmic tail of the TCR is very short and therefore unlikely to be involved in signaling. CD3 and the delta chain form together with the TCR a so-called T cell receptor complex.

CD3 epsilon is a type I transmembrane protein expressed on the surface of certain T cells. It is involved in the T Cell Receptor (TCR) complex and interacts with other domains of the complex. One of these interaction partners is CD3 γ, which is expressed as a 1: a stoichiometric ratio of 1 binds to CD3 ε (De la Hera et al, J.exp. Med.1991; 173: 7-17). It is believed that binding of the TCR to the MHC-peptide complex on the surface of an Antigen Presenting Cell (APC) and subsequent movement of the T cell along the APC results in some rotation of the TCR complex which results in CD3 epsilon and CD3 gamma being misaligned with each other, which is necessary for efficient TCR signalling and hence activation of the T cell. Some antibodies against CD3 epsilon have been shown to induce TCR signaling, while others do not. TCR-activating antibodies typically bind to an exposed epitope on CD3 epsilon, while some non-stimulatory antibodies have been shown to bind to the interface between CD3 epsilon and CD3 gamma, or both CD3 epsilon and CD3 gamma, and thus may interfere with the relative displacement of CD3 epsilon and CD3 gamma (Kim et al, JBC. 2009; 284: 31028-.

It is well recognized that peptide-MHC complexes bind TCR with low affinity and rapid off-rate (off-rate) (Matsui et al, science.1991; 254: 1788-. This low affinity has been shown to help allow some peptide-MHC complexes to trigger many TCRs in series by repeated association and dissociation (Valituti et al, Nature.1995; 375: 148-. This continuous triggering is critical to maintaining signaling over a period of time that allows the T cells to eventually reach the activation threshold (Valitetti et al, immunol. today. 1997; 18: 299-304; Lanzavecchia et al, cell. 1999; 96: 1-4). This finding is supported by the following idea: high affinity anti-CD 3 antibodies are not effective at stimulating T cells compared to peptide-MHC complexes because they are expressed as 1: a stoichiometric ratio of 1 triggers the TCR (Viola et al, Science 1996; 273: 104-. In fact, in a direct comparison of three derivatives of anti-CD 3 ε antibody TR66, all of which bind with different affinities, wild-type TR66 with intermediate affinity showed the best efficacy in T cell activation when compared to derivatives with higher or lower affinity (Bortoletto et al, J.Immuno.2002; 32: 3102-. Therefore, K with TR66_DClose K_DIs ideal for stimulating T cells. Has been achieved by using surface plasmon resonance(SPR) technique and determination of the affinity of TR66 by flow cytometry yielded equilibrium dissociation constants of 2.6X10^-7M (Moore et al, blood.2011; 117:4542-^-7M (Amann et al, Cancer Res.2008; 68: 143-. For this purpose, it is advisable to use a binding affinity of less than 10^-8M anti-CD 3 antibody (US 7,112,324), and published T cell stimulatory antibodies for human therapeutic use, which bind with an affinity to human CD3 epsilon in the same range. Thus, based on a series of TCR triggering theories, and in agreement with published anti-CD 3 epsilon antibody results, monoclonal antibodies with significantly better affinity than those published would not be expected to produce a stronger stimulatory effect on T cells, but would instead be expected to be weaker activators.

Some published antibodies against CD3 epsilon have been generated by immunizing animals with T cell preparations and subsequently isolating monoclonal antibodies by the so-called hybridoma procedure. The disadvantage of this approach is, on the one hand, the non-selective immune response against various antigens of foreign (human) T cells in animals and, on the other hand, the inefficient hybridoma procedure, thereby reducing the possibility of identifying monoclonal antibodies with T cell stimulatory activity, also because these agonistic antibodies may represent a minority of the total anti-CD 3 epsilon antibodies. Immunization with a linear peptide spanning the target epitope may improve the selectivity of the immune response, but may result in antibodies that do not recognize native full-length CD3 epsilon or may produce suboptimal TCR stimulation.

For immunization of animals with other type I transmembrane proteins, the use of a purified extracellular domain (ECD) is particularly useful. However, the purified ECD of CD3 epsilon tends to aggregate and the structure of the aggregate may be altered compared to the native protein. Furthermore, this approach may preferentially result in binding of the antibody to the interface between CD3 epsilon and CD3 gamma. In contrast, complexes of CD3 ε and CD3 γ produced as single-chain proteins linked by a flexible peptide linker can be purified into the monomeric moiety and its native conformation (Kim et al, JMB. 2000; 302: 899-916). However, immunization of animals with this CD3 ε/γ single chain protein may result in simultaneous binding of the antibody to CD3 ε and CD3 γ, which would result in antagonism.

Several antibodies against human CD3 epsilon have been developed in the past.

Monoclonal antibody SP34 is a murine antibody that cross-reacts with non-human primate CD3 and is also capable of inducing cell proliferation on human and non-human primate PBMCs (Pessano et al, The T3/T cell receptor complex: anti-inflammatory differentiation between The two 20kD T3(T3 and T3) subbunits. EMBOJ 4(1985)337 and 344).

WO 2007/042261 and WO2008/119567, both assigned to Micromet (now Amgen Research), disclose cross-reactive linkers (binders) against epitopes FSEXE and QDGNE in CD3 epsilon, respectively. In the objection program proposed by some objectors against the granted european patent EP 2155783 (based on the regional phase of WO 2008/119567), SP34 is proposed to bind also to the epitope QDGNE.

WO2014/191113 discloses a cross-reactive linker directed against a novel epitope at the N-terminus of CD3 epsilon, wherein the epitope comprises amino acid residue N4 as a residue essential for binding and wherein the epitope further comprises amino acid residue E6 as a residue involved in binding. These antibodies can be demonstrated to have high affinity and high potency. However, although it can also be demonstrated in WO2014/191113 that the antibodies disclosed in the present application cross-react with CD3 from non-human primates in vitro, they cannot demonstrate cross-reactivity with cynomolgus monkey CD3 in a cellular environment. Thus, these antibodies have limited utility in terms of preclinical development of pharmaceutical products comprising anti-CD 3 antibodies.

Thus, there remains a great unmet need to develop new CD3 binding molecules, in particular new anti-CD 3 antibodies, which have the required affinity and potency properties, but which are also cross-reactive with other species, in particular with non-human primates (e.g. cynomolgus monkeys), both in vitro and in a cellular environment.

Disclosure of Invention

The present invention addresses the above needs and provides novel antibodies specific for human CD3, particularly antibodies specific for the CD3 epsilon domain. To date, the prior art has not achieved or suggested the solution provided by the present invention, namely a CD3 binding molecule, in particular an anti-CD 3 antibody obtained by peptide immunization of rabbits and screening of affinity matured memory B cells, and in particular a CD3 binding molecule, in particular an anti-CD 3 antibody, in particular an antibody specific for the CD3 epsilon domain, with desirable cross-reactivity properties. The novel CD3 antibodies of the invention have desirable affinity and potency profiles, both in vitro and in cells, and are cross-reactive with other species, particularly non-human primates (e.g., cynomolgus monkeys). In addition, the antibodies of the invention have good biophysical properties, such as quality, stability or solubility, defined, for example, by the percentage of antibody in monomeric form and the thermal unfolding determined by Differential Scanning Fluorescence (DSF).

Accordingly, in a first aspect, the present invention relates to an antibody or functional fragment thereof specific for human CD3, comprising:

a variable light chain, wherein the variable light chain comprises, from N-terminus to C-terminus, the region LFW1-LCDR1-LFW2-LCDR2-LFW3-LCDR3-LFW4, wherein each LFW represents a light chain framework region and each LCDR represents a light chain complementarity determining region, and wherein the LCDRs are together connected to a light chain complementary determining region taken from the group consisting of SEQ ID NO: 4 has at least 90% sequence identity to the corresponding LCDR of the VL sequence;

and

a variable heavy chain, wherein the variable light chain comprises, from N-terminus to C-terminus, the regions HFW1-HCDR1-HFW2-HCDR2-HFW3-HCDR3-HFW4, wherein each HFW represents a heavy chain framework region and each HCDR represents a heavy chain complementarity determining region, and wherein the HCDRs together are a heavy chain complementarity determining region taken from the group consisting of SEQ ID NO: the corresponding HCDR of the VH sequence of 8 has at least 90% sequence identity.

In a second aspect, the present invention relates to a multispecific polypeptide comprising an antibody or functional fragment thereof of the present invention.

In a third aspect, the present invention relates to a pharmaceutical composition comprising an antibody or a functional fragment thereof of the present invention or a multispecific polypeptide of the present invention, and a pharmaceutically acceptable carrier and/or excipient.

In a fourth aspect, the invention relates to an antibody or functional fragment thereof of the invention, or a multispecific polypeptide of the invention, for use as a medicament.

In a fifth aspect, the invention relates to a nucleic acid sequence or a collection of nucleic acid sequences encoding an antibody or functional fragment thereof of the invention.

In a sixth aspect, the invention relates to a vector or collection of vectors comprising a nucleic acid sequence or collection of nucleic acid sequences of the invention.

In a seventh aspect, the present invention relates to a host cell, in particular an expression host cell, comprising a nucleic acid sequence or a collection of nucleic acid sequences of the present invention, or a vector or a collection of vectors of the present invention.

In an eighth aspect, the invention relates to a method for producing an antibody or a functional fragment thereof of the invention, comprising the step of expressing a nucleic acid sequence or a collection of nucleic acid sequences of the invention, or a vector or a collection of vectors of the invention, or a host cell of the invention, in particular an expression host cell.

In a ninth aspect, the present invention relates to a method of producing a multispecific construct comprising the step of cloning in one or more steps one or more nucleic acid sequences encoding an antibody or functional fragment thereof according to the present invention into a multispecific construct comprising a nucleic acid sequence encoding at least a second binding domain or fragment thereof and optionally one or more additional binding domains or fragments thereof.

Drawings

FIG. 1 shows the monomer content of each sample as determined by SE-HPLC at 4 ℃ and a concentration of 10mg/mL, initially (d0) and over a 28 day storage time.

FIG. 2 shows the synthesis of PRO460(IL23RxCD 3) from human PBMC_{I2C Amgen}) And PR0389(IL23RxCD 3)_{1st gen Numab}) Induced T cell-mediated target cell depletion. The left panel shows cell lysis of target expressing cells, while the right panel shows cell lysis of target negative cells. The half maximal Effector Concentration (EC) of the molecule in the presence of target expressing cells is depicted below the graph₅₀) The numerical value of (c).

FIG. 3 shows the molecule PRO460(IL23RxCD 3) determined by FC assay_{I2C Amgen}) And PR0389(IL23RxCD 3)_{1st gen Numab}) T cell activation of (3). The left panel shows activation in the presence of target expressing cells, while the right panel shows activation in the presence of target negative cells.

FIG. 4 shows the synthesis of human PBMC from PRO624(IL23RxCD 3)_{2nd gen Numab}) And PR0389(IL23RxCD 3)_{1st gen Numab}) Induced T cell-mediated target cell depletion. The left panel shows cell lysis of target expressing cells, while the right panel shows cell lysis of target negative cells. The half maximal Effector Concentration (EC) of the molecule in the presence of target expressing cells is depicted below the graph₅₀) The numerical value of (c).

FIG. 5 shows the molecule PRO624(IL23RxCD 3) as determined by FC assay_{2nd gen Numab}) And PR0389(IL23RxCD 3)_{1st gen Numab}) T cell activation of (3). The left panel shows activation in the presence of target expressing cells, while the right panel shows activation in the presence of target negative cells.

FIG. 6 shows the molecule PRO624(IL23RxCD 3) as determined by the NFAT reporter gene assay_{2nd gen Numab}) And PR0389(IL23RxCD 3)_{1st gen Numab}) T cell activation of (3). The left panel shows activation in the presence of target expressing cells, while the right panel shows activation in the presence of target negative cells. The half maximal Effector Concentration (EC) of the molecule in the presence of target expressing cells is depicted below the graph₅₀) The numerical value of (c).

FIG. 7 shows the isolation of PRO624(IL23RxCD 3) using cynomolgus monkey PBMC_{2nd gen Numab}) And PR0389(IL23RxCD 3)_{1st gen Numab}) Induced T cell-mediated target cell depletion. The left panel shows cell lysis of target expressing cells, while the right panel shows cell lysis of target negative cells. The half maximal Effector Concentration (EC) of the molecule in the presence of target expressing cells is depicted below the graph₅₀) The numerical value of (c).

FIG. 8 shows PRO957 (A) and PRO957 (B) human PBMC after 16 hours (A) and after 40 hours (B)HER2xCD3_{2nd gen Numab}) And PR0956(HER2xCD 3)_{I2C Amgen}) Induced T cell-mediated target cell depletion. The left panel shows cell lysis of target expressing cells, while the right panel shows cell lysis of target negative cells. The half maximal Effector Concentration (EC) of the molecule in the presence of target expressing cells is depicted below the graph₅₀) The numerical value of (c).

FIG. 9 shows the molecule PRO957(HER2xCD 3) determined by FC assay after 16 hours (A) and after 40 hours (B)_{2nd gen Numab}) And PR0956(HER2xCD 3)_{I2C Amgen}) T cell activation of (3). The left panel shows activation in the presence of target expressing cells, while the right panel shows activation in the presence of target negative cells.

Detailed Description

The present disclosure relates to novel antibodies specific for human CD3, in particular antibodies specific for the CD3 epsilon domain.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

The terms "comprising" and "including" are used herein in their open and non-limiting sense unless otherwise indicated. With respect to such latter embodiments, the term "comprising" thus includes the narrower term "consisting of … …".

The terms "a" and "an" and "the" and similar references in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. For example, the term "a cell" includes a plurality of cells, including mixtures thereof. When plural forms are used for compounds, salts, etc., this is also considered to mean a single compound, salt, etc.

In a first aspect, the present invention relates to an antibody or functional fragment thereof specific for human CD3, comprising: (a) a variable light chain, wherein the variable light chain comprises, from N-terminus to C-terminus, the region LFW1-LCDR1-LFW2-LCDR2-LFW3-LCDR3-LFW4, wherein each LFW represents a light chain framework region and each LCDR represents a light chain complementarity determining region, and wherein the LCDRs are together connected to a light chain complementary determining region taken from the group consisting of SEQ ID NO: 4 has at least 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% sequence identity, preferably at least 90% sequence identity; and (b) a variable heavy chain, wherein the variable light chain comprises, from N-terminus to C-terminus, the regions HFW1-HCDR1-HFW2-HCDR2-HFW3-HCDR3-HFW4, wherein each HFW represents a heavy chain framework region and each HCDR represents a heavy chain complementarity determining region, and wherein the HCDRs are together with a light chain constant region taken from the group consisting of SEQ ID NO: the corresponding HCDR of the VH sequence of 8 has at least 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% sequence identity, preferably at least 90% sequence identity.

In the context of the present invention, the term "antibody" is used as a synonym for "immunoglobulin" (Ig), which is defined as a protein belonging to the IgG, IgM, IgE, IgA, IgY or IgD class (or any subclass thereof) and includes all conventionally known antibodies. A naturally occurring "antibody" is a glycoprotein comprising at least two heavy (H) chains and two light (L) chains interconnected by disulfide bonds. Each heavy chain consists of a heavy chain variable region (abbreviated herein as VH) and a heavy chain constant region. The heavy chain constant region comprises three domains, CH1, CH2, and CH 3. Each light chain consists of a light chain variable region (abbreviated herein as VL) and a light chain constant region. The light chain constant region comprises a domain CL. The VH and VL regions may be further subdivided into regions of hypervariability, termed Complementarity Determining Regions (CDRs), and more conserved regions, termed framework regions (FWs). Each VH and VL is composed of three CDRs and four FWs arranged from amino-terminus to carboxy-terminus in the following order: FW1-CDR1-FW2-CDR2-FW3-CDR3-FW 4. The variable regions of the heavy and light chains contain binding domains that interact with antigens.

The term "antibody fragment" refers to at least a portion of an intact antibody or a recombinant variant thereof, and the term "functional fragment" or "functional antibody fragment" or "antigen-binding fragment" refers to an antibody fragment comprising at least an antigen-binding domain (e.g., a variable region portion of an intact antibody) sufficient to confer recognition and specific binding of a target (e.g., an antigenic determinant of an antigen) by the functional antibody fragment. Examples of functional antibody fragments include, but are not limited to, Fab ', F (ab')2 and Fv fragments, scFv antibody fragments, linear antibodies, single domain antibodies (such as sdAb (VL or VH), camelid VHH domains) and multispecific molecules formed from antibody fragments, e.g., bivalent fragments, comprising two or more Fab fragments linked, e.g., by disulfide bonds of a hinge region, or two or more, e.g., separate CDRs or other epitope-binding fragments of two linked antibodies. In one embodiment, the functional fragment of the invention is an scFv. Antibody fragments may also be incorporated into single domain antibodies, macroantibodies (maxibodes), minibodies (minibodies), nanobodies (nanobodies), intrabodies (intrabodies), diabodies (diabodies), trifunctional antibodies (triabodies), tetrafunctional antibodies (tetrabodies), v-NAR and bis-scFv (see, e.g., Hollinger and Hudson, Nature Biotechnology 23: 1126-. Antibody fragments can also be grafted into scaffolds based on polypeptides such as fibronectin type III (Fn3) (see U.S. patent No. 6,703,199 which describes fibronectin polypeptide minibodies). An "antigen binding region" or "antigen binding domain" of an antibody is typically present in one or more hypervariable regions of the antibody, i.e. the CDR1, CDR2 and/or CDR3 regions; however, variable "framework" regions may also play an important role in antigen binding, for example by providing a framework for the CDRs. The constant regions of antibodies may mediate the binding of immunoglobulins to host tissues or factors, including various cells of the immune system (e.g., effector cells) and the first component of the classical complement system (Clq). As used herein, the term "antibody" includes, for example, monoclonal, humanized or chimeric antibodies. The antibody may be of any isotype (e.g., IgG, IgE, IgM, IgD, IgA, and IgY), class (e.g., IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2), or subclass.

"complementarity determining regions" ("CDRs") are amino acid Sequences having boundaries determined using any of a number of well-known protocols, including Kabat et Al (1991), "Sequences of Proteins of immunological Interest," 5th Ed.public Health Service, National Institutes of Health, Bethesda, MD ("Kabat" numbering scheme), Al-Lazikani et Al, (1997) JMB 273,927-948 ("Chothia" numbering scheme) and ImmunoGenTiCs (IMGT) numbering (Lefranc, M. -P., the Immunologest, 7,132-136 (1999); Lefranc, M. -P. et Al, Comp. ImmunoL. 27,55-77(2003), ("IMGT" 2003 "e.g., Dev. (1999); Lefranc, M. -P. et Al., VH. 35, 27,55-77, 2003; 2003) (e.g., for example, VH 34-VH 11-CDR 35), and VH 11-VH-35 (11) residues in the classical CDR 34-VH-H-, 50-56(LCDR2) and 89-97(LCDR 3). According to Chothia, CDR amino acids in VH are numbered 26-32(HCDR1), 52-56(HCDR2) and 95-102(HCDR 3); and the amino acid residues in VL are numbered 24-34(LCDR1), 50-56(LCDR2) and 89-97(LCDR 3). By combining the CDR definitions of Kabat and Chothia, the CDRs are composed of amino acid residues 26-35(HCDR1), 50-65(HCDR2) and 95-102(HCDR3) in the human VH and amino acid residues 24-34(LCDR2), 50-56(LCDR2) and 89-97(LCDR3) in the human VL. According to IMGT, the CDR amino acid residues in the VH are numbered about 26-35(HCDR1), 51-57(HCDR2) and 93-102(HCDR3), and the CDR amino acid residues in the VL are numbered about 27-32(LCDR2), 50-52(LCDR2) and 89-97(LCDR3) (numbering according to "Kabat"). According to IMGT, the CDRs of an antibody can be determined using the program IMGT/DomainGap Align.

In the context of the present invention, unless otherwise specifically indicated, the numbering system ("AHo numbering") proposed by Honegger & Pl ü ckthun is used (Honegger & Pl ü ckthun, J.mol.biol.309(2001) 657) 670.) furthermore, the following residues are defined as CDRs LCDR1 (also referred to as CDR-L1): L24-L42; LCDR2 (also referred to as CDR-L2): L58-L72; LCDR3 (also referred to as CDR-L3): L107-L138; HCDR1 (also referred to as CDR-H1): H27-H42; HCDR2 (also referred to as CDR-H2): H57-H76; HCDR3 (also referred to as CDR-H3H 108-138): for clarity, the numbering according to the Honegger & Pl ü, is not taken into account for the different amino acid sequences in the natural domain, especially the VH numbering system, and the VH sequences are not generally given as the diversity of the VH1, and the VH sequences are not present in the given sub-GAL 1.

Preferably, the "antigen-binding region" comprises at least amino acid residues 4 to 138 of the Variable Light (VL) chain and 5 to 138 of the Variable Heavy (VH) chain (in each case according to honeyger&Pl ü ckthun numbering), more preferably amino acid residues 3 to 144 of VL and 4 to 144 of VH, and particularly preferably the entire VL and VH chain (amino acid positions 1 to 149 of VL and 1 to 149 of VH)₂Fragments, Fab fragments, Fv and scFv domains. F (ab')₂Or the Fab may be engineered to minimize or completely eliminate the intermolecular disulfide interaction that occurs between CH1 and the CL domain. The antibodies of the invention or functional fragments thereof may be part of a bi-or multifunctional construct, as described in [0076 ]]To [0111]As further described in the paragraph.

The following terms are used to describe the sequence relationship between two or more polynucleotide or amino acid sequences: "sequence identity" or "percent sequence identity". As used herein, the term "sequence identity" is determined by counting the maximum number of amino acid residues that are identical between two polypeptide sequences, where gaps (gaps) and/or insertions may be considered in order to allow for the maximum degree of sequence overlap. For example, two identical 100mer polypeptides have 100% sequence identity. When they differ by a single mutation, or when a polypeptide contains an amino acid deletion, the sequence identity is 99% (99 positions are identical). In other words, "percent sequence identity" is calculated by comparing two optimally aligned sequences over a comparison window, determining the number of positions at which the same nucleobase (e.g., A, T, C, G, U or I) or amino acid residue occurs in both sequences to yield the number of matched positions, dividing the number of matched positions by the total number of positions in the comparison window (i.e., the window size), and multiplying the result by 100 to yield the percentage of sequence identity. The term "sequence similarity" is the degree of similarity between two sequences when the two sequences are compared. Optimal alignments of sequences can be made for comparison as necessary or desired, for example, by the local homology algorithm of Smith and Waterman (adv. appl. Math.2: 482(1981)), by the homology alignment algorithm of Needleman and Wunsch (J.mol. biol.48: 443-53(1970)), by the similarity search method of Pearson and Lipman (Proc. Natl. Acad. Sci.USA 85:2444-48(1988)), by computer implementation of these algorithms (e.g., BEGAP FIT, FASTA and TFASTA in the Wisconsin Genetics package, Genetics computer group,575Science Dr., Madison, Wis.) or by visual inspection. (see generally Ausubel et al (eds.), Current Protocols in Molecular Biology,4th ed., John Wiley and Sons, New York (1999)). Unless otherwise indicated herein, the degree of sequence similarity referred to herein is determined by using the Dayhoff PAM matrix (M.O.Dayhoff, R.Schwartz, B.C.Orcutt: A model of evolution Change Proteins, page 345-352; in: Atlas of protein sequence and structure, national biological Research Foundation, 1979).

The term "amino acid" refers to naturally occurring and synthetic amino acids, as well as amino acid analogs and amino acid mimetics that function in a manner similar to the naturally occurring amino acids. Naturally occurring amino acids are those encoded by the genetic code, and those amino acids that are subsequently modified, such as hydroxyproline, γ -carboxyglutamic acid, and O-phosphoserine. The terms "polypeptide" and "degradin" are used interchangeably herein to refer to a polymer of amino acid residues. These terms apply to amino acid polymers in which one or more amino acid residues is an artificial chemical mimetic of a corresponding naturally occurring amino acid, as well as to naturally occurring amino acid polymers and non-naturally occurring amino acid polymers. Unless otherwise indicated, a particular polypeptide sequence also implicitly encompasses conservatively modified variants thereof.

As used herein, the term "binding specificity" refers to the ability of a single antibody binding site to react with one antigenic determinant, but not with a different antigenic determinant. As used herein, a "binding molecule" is "target-specific/specific for a target," "specifically recognizes," or "specifically binds" a target (e.g., human CD3) when the binding molecule is capable of distinguishing between such a target biomolecule and one or more standard molecules, as binding specificity is not absolute, but rather relative in nature. In its most general form (and when no reference is made to a definition), by "specific binding" is meant the ability of a binding molecule to distinguish between a target biomolecule of interest and an unrelated biomolecule, as determined, for example, according to specific detection methods known in the art. Such methods include, but are not limited to, Western blotting, ELISA, RIA, ECL, IRMA, SPR (surface plasmon resonance) testing, and peptide scanning. For example, standard ELISA assays can be performed. Scoring can be performed by standard color development (e.g., with secondary antibodies to horseradish peroxide and tetramethyl benzidine with hydrogen peroxide). The response in some wells is scored by optical density (e.g., at 450 nm). A typical background (negative reaction) may be about 0.1 OD; a typical positive reaction may be about 1 OD. This means that the ratio between positive and negative scores can be 10-fold or higher. In another embodiment, an SPR assay can be performed in which at least a 10-fold, preferably at least a 100-fold difference between background and signal indicates specific binding. Typically, the determination of binding specificity is not performed by using a single standard biomolecule, but rather a set of about three to five unrelated biomolecules (e.g., milk powder, transferrin, etc.). The antibodies or functional fragments thereof of the present invention have binding specificity for human CD3, preferably human CD3 epsilon.

In one embodiment, the antibody or functional fragment thereof of the invention has binding specificity to human CD3 and to non-chimpanzee primate CD 3. It will be apparent to the skilled person that the antibody of the invention, or a functional fragment thereof, having cross-species specificity as defined herein, may also bind to e.g. chimpanzee CD3 without departing from the scope of the invention. On the other hand, it is clear that antibodies of the invention or functional fragments thereof that bind only to human CD3 and not to non-chimpanzee primate CD3 are excluded from the scope of the invention. This is in contrast to binding domains that apply to binding only to non-chimpanzee primate CD3, but not to human CD3, e.g., those of monoclonal antibody FN-18.

As used herein, "non-chimpanzee primate" or "non-chimpanzee primate (non-chimpprimate)" or grammatical variants thereof refers to any primate other than chimpanzee, i.e., other than an animal belonging to the genus chimpanzee (genus Pan), including the species bonobo (Pan paniscus) and chimpanzee (panrogodytes), also known as apes (antropitus troglodytes) or orangutans (simiastatus). "primates", "primate species", "primates" or grammatical variants thereof refer to one order of mammals of the class eutheroians (eutherins), which is divided into two sub-orders pro apes (prosimians) and anthropoids (antroids) and includes humans, apes, monkeys and lemurs. Specifically, "primate" as used herein includes the suborder Prosimian (Stresrhiri) (non-tarsier Prosimians), which includes the suborder Fouca (Lemultiformes) (which itself includes the general family mouse, the family Viridae (Cheirogoleoidea) and the family Foucaidae (Lemusoidea)), the suborder Machimuriforme (Chiromyceae) (which itself includes the family Viridae (Daubenonidae)) and the suborder Machimuriformes (Lorisformes) (which itself includes the family Laristidae (Lorisidedae) and the family Conidioperaceae (Galagidae)). As used herein, "primate" also includes the suborder rhinoideae (haplor, which includes the suborder Tarsiiformes (Tarsiiformes), which itself includes the family of ophthalmic monkeys (Tarsiidae), the suborder simians (simiformes), which itself includes the order Platyrrhini (Platyrrhini) or a new world monkey, and the order stenoptera (Catarrhini), which includes the family of monkeys (cercopithecidae) or an old world monkey. Most preferred is Cynomolgus monkey (Macaca fascicularis) (also known as Cynomolgus monkey, and hence in the examples "Cynomolgus monkey"). Suitably, the antibody or functional fragment thereof of the invention has binding specificity to human CD3 and cynomolgus monkey CD 3.

Furthermore, depending on the context, the term "specific binding" may also refer to the ability of a binding molecule to distinguish between a target biomolecule and one or more closely related biomolecules, which serve as a standard point, for example a CD3 molecule from a different species, for example murine CD 3. Furthermore, "specific binding" may relate to the ability of a binding molecule to distinguish between different parts of its target antigen, e.g. different domains, regions or epitopes of the target biomolecule (in particular the CD3 epsilon domain), or one or more key amino acid residues or stretches of amino acid residues of the target biomolecule.

In one embodiment, the antibody or functional fragment thereof of the invention has binding specificity to human CD3 epsilon.

The term "CD 3" refers to a molecule that is expressed as part of a T cell receptor and has the meaning commonly assigned to it in the art. In humans, it comprises the CD3 subunits CD3 epsilon, CD3 delta, and CD3 gamma, singly or in independent combination. Non-chimpanzee primate CD3 antigens referred to herein are, for example, cynomolgus monkey CD3 and Macaca multto (Macaca mulatt) CD 3. In cynomolgus macaques, it includes CD3 ε FN-18 negative and CD3 ε FN-18 positive, CD3 γ and CD3 δ. In the common macaque, it includes CD3 epsilon, CD3 gamma, and CD3 delta.

Preferably, as used herein, said CD3 specifically relates to CD3 epsilon. The term "human CD3 epsilon" specifically refers to human CD3 epsilon having GenBank accession No. NM _000733, UniProt ID No. P07766, or a variant thereof, which is identified herein as SEQ ID NO: 19 reproduction. The CD3 epsilon "FN-18 negative" of cynomolgus macaques (i.e., CD3 epsilon not recognized by monoclonal antibody FN-18 due to the polymorphism described above) is indicated in GenBank accession number AB 073994. The CD3 epsilon "FN-18 positive" of cynomolgus macaques (i.e., CD3 epsilon recognized by monoclonal antibody FN-18) is indicated in GenBank accession number AB 073993.

Human CD3 γ is indicated in GenBank accession No. NM 000073. Human CD3 δ is indicated in GenBank accession No. NM 000732. CD3 gamma is indicated in GenBank accession No. AB073992 for cynomolgus macaques. CD3 δ of cynomolgus macaques is indicated in GenBank accession No. AB 073991.

Suitably, the antibody or functional fragment thereof of the invention targets human and cynomolgus monkey (cynomolgus monkey) CD3 epsilon.

Suitably, the antibody of the invention is a monoclonal antibody. As used herein, the term "monoclonal antibody" or "monoclonal antibody composition" refers to an antibody that is substantially identical to an amino acid sequence derived or derived from the same genetic source. Monoclonal antibody compositions exhibit binding specificity and affinity for a particular epitope, or for multiple particular epitopes.

In the context of the present invention, the term "epitope" refers to the part of a given target biomolecule that is required for specific binding between the target biomolecule and the binding molecule. Epitopes may be continuous, i.e. formed by adjacent structural elements present in the target biomolecule, or discontinuous, i.e. formed by structural elements at different positions in the primary sequence of the target biomolecule (e.g. in the amino acid sequence of the protein as target), but in close proximity in the three-dimensional structure adopted by the target biomolecule, e.g. in body fluids.

Antibodies of the invention include, but are not limited to, chimeric, human and humanized antibodies.

The term "chimeric antibody" (or functional fragment thereof) is an antibody molecule (or functional fragment thereof) in which (a) the constant region or a portion thereof is altered, replaced or exchanged such that the antigen binding site (variable region) is linked to a constant region of a different or altered class, effector function and/or species, or an entirely different molecule that confers new properties to the chimeric antibody, e.g., an enzyme, toxin, hormone, growth factor, drug, etc.; (b) the variable region or a portion thereof is altered, replaced or exchanged by a variable region having a different or altered antigenic specificity. For example, a mouse antibody can be modified by replacing its constant region with a constant region from a human immunoglobulin. Chimeric antibodies can retain their antigen-recognizing specificity while having reduced antigenicity in humans compared to the original mouse antibody, due to substitution by human constant regions.

As used herein, a "humanized" antibody (or functional fragment thereof) is an antibody (or functional fragment thereof) that retains the reactivity of a non-human antibody while having less immunogenicity in humans. This can be achieved, for example, by retaining the non-human CDR regions and replacing the remainder of the antibody with its human counterpart (i.e., the framework portions of the constant and variable regions). Additional framework region modifications can be made within the human framework sequence as well as CDR sequences derived from the germline of another mammalian species. Humanized antibodies of the invention may comprise amino acid residues that are not encoded by human sequences (e.g., mutations introduced by random or site-specific mutagenesis in vitro or by somatic mutation in vivo, or by conservative substitutions to promote stability or manufacturing). See, for example, Morrison et al, Proc. Natl. Acad. Sci. USA,81: 6851-; morrison and Oi, adv. Immunol.,44:65-92,1988; verhoeyen et al, Science 239: 1534-; padlan, Molec. Immun.,28:489-498, 1991; and Padlan, Molec. Immun.,31:169-217, 1994. Other examples of antibody engineering techniques include, but are not limited to, Xoma technology disclosed in U.S. patent No. 5,766,886.

As used herein, the term "recombinant humanized antibody" includes all humanized antibodies of the invention that are prepared, expressed, produced or isolated by recombinant means, e.g., antibodies isolated from an animal (e.g., a mouse); antibodies expressed using recombinant expression vectors transfected into host cells, antibodies isolated from recombinant, combinatorial human antibody libraries, or antibodies prepared, expressed, produced, or isolated by any other means involving splicing of human immunoglobulin gene sequences to other DNA sequences. Such recombinant human antibodies have variable and constant regions (if present) derived from human germline immunoglobulin sequences. However, such antibodies may be subjected to in vitro mutagenesis (or, when using animals transgenic for human IgG sequences, in vivo somatic mutagenesis), and thus the amino acid sequences of VH (antibody heavy chain variable region) and VL (antibody light chain variable region) of the recombinant antibody are sequences that, although derived from and related to human germline VH and VL sequences, may not naturally occur in the human antibody germline.

Suitably, the antibody or functional fragment of the invention is an artificial or isolated antibody or functional fragment thereof. As used herein, the term "artificial antibody" refers to an antibody or functional fragment thereof which, by virtue of its origin or manipulation: (i) the expression product as part of an expression vector is present in a host cell, or (ii) is linked to a protein or other chemical moiety that is different from its native linkage, or (iii) does not occur naturally. As used herein, the term "isolated antibody" refers to an antibody that is expressed in a host cell and purified from a protein of interest by gel chromatography. The term "isolated antibody" also refers to an antibody that is substantially free of other antibodies having different antigenic specificities (e.g., an isolated antibody that specifically binds human CD3 is an antibody that is substantially free of antibodies that specifically bind antigens other than human CD 3). However, an isolated antibody that specifically binds human CD3 may be cross-reactive to other antigens, such as CD3 molecules from other species (e.g., non-human primate and/or rodent CD 3). Furthermore, the isolated antibody may be substantially free of other cellular material and/or chemicals.

In one embodiment, the invention relates to an antibody or functional fragment thereof comprising (a) a light chain variable region as set forth in SEQ id no: LCDR1 shown at 1; (b) as shown in SEQ ID NO: LCDR2 shown at 2; (c) as shown in SEQ ID NO: LCDR3 shown at 3; (d) as shown in SEQ ID NO: HCDR1 shown in fig. 5; (e) as shown in SEQ ID NO: HCDR2 shown at 6; and (f) as set forth in SEQ ID NO: HCDR3 shown in fig. 7.

The antibodies of the invention, or functional fragments thereof, comprise a variable heavy chain (VH) domain and a variable light chain (VL) domain. In the context of the present invention, the terms "VH" ("variable heavy chain"), "vk" and "V λ" refer to a family of antibody heavy and light chain sequences grouped by sequence identity and homology. Methods for determining sequence homology, for example by using homology search matrices, such as BLOSUM (Henikoff, S. & Henikoff, J.G., Proc. Natl. Acad. Sci. USA 89 (1992)) 10915-10919, and methods for grouping sequences according to homology are well known to those of ordinary skill in the art. For VH, Vkappa and Vlambda, different subfamilies can be identified, for example, as shown in Knappik et al, J.mol.biol.296(2000)57-86, where VH is grouped into VH1A, VH1B and VH2-VH6, Vkappa is grouped into Vkappa 1-Vkappa 4, and Vlambda is grouped into V lambda 1-V lambda 3. In vivo, the antibody vk, V λ and VH chains are the result of random rearrangements of germline κ chain V and J segments, germline λ chain V and J segments, and heavy chain V, D and J segments, respectively. The subfamily to which a given antibody variable chain belongs is determined by the corresponding V fragment, and in particular by the framework regions FW1-FW 3. Thus, any VH sequence characterized in this application by only a particular set of framework regions HFW1 to HFW3 may be combined with any HFW4 sequence, for example an HFW4 sequence taken from one of the heavy chain germline J segments, or an HFW4 sequence taken from a rearranged VH sequence. In a specific embodiment, the HFW4 sequence is WGQGTLVTVSS.

Suitably, the invention provides an antibody or functional fragment thereof that specifically binds CD3 (e.g. human CD3 protein, in particular human CD3 epsilon), wherein said antibody or functional fragment thereof comprises a VH4 or VH3 domain, preferably a VH3 domain.

Suitably, the invention provides an antibody or functional fragment thereof that specifically binds CD3 (e.g. human CD3 protein, particularly human CD3 epsilon), wherein said antibody or functional fragment thereof comprises (i) a V κ framework FW1, FW2 and FW3, particularly a V κ 1 or V κ 3 framework, preferably a V κ 1 framework FW1 to FW3, and (ii) a framework FW4 selected from the group consisting of V κ FW4, particularly V κ 1FW4, V κ 3FW4 and V λ FW 4. Suitable vk 1FW1 to FW3 are substituted with one or more amino acids taken from the group according to SEQ ID NO: 4 has at least 60%, 70%, 80%, 90% sequence identity, preferably at least 90% sequence identity to the corresponding framework region. Suitable vk 1FW4 are substituted with a residue taken from seq id NO: 4 has at least 60%, 70%, 80%, 90% sequence identity, preferably at least 90% sequence identity to the corresponding FW4 of the vk 1 sequence. Suitably, vk 1FW4 is taken from the amino acid sequence according to SEQ ID NO: 4, FW4 of the V κ 1 sequence. Suitable V λ FW4 are as set forth in SEQ ID NO: 17 or SEQ ID NO: 18, respectively. In one embodiment, the invention provides an antibody or functional fragment thereof that specifically binds CD3 (e.g., human CD3 protein, particularly human CD3 epsilon), wherein said antibody or functional fragment thereof comprises V λ FW4 comprising an amino acid sequence substantially identical to a sequence selected from the group consisting of SEQ ID NOs: 17 to SEQ ID NO: 18, preferably any one of SEQ ID NO: 17 has an amino acid sequence which is at least 60%, 70%, 80%, 90% identical to the amino acid sequence of seq id No. 17.

In a specific embodiment, the variable light chain is a vk 1 light chain and/or the variable heavy chain is a VH3 chain. In another specific embodiment, the variable light chain is a chimeric light chain comprising vk framework regions I-III and V framework region IV. In one embodiment, the light chain is a chimeric light chain comprising:

(i) are respectively SEQ ID NO: 1. LCDR1, LCDR2, and LCDR3 sequences of 2 and 3;

(ii) human vk framework regions FW1 to FW3, in particular human vk 1 framework regions FW1 to FW 3;

(iii) FW4 selected from (a) human V λ germline sequences of FW4, in particular selected from SEQ ID NO: 17 and SEQ ID NO: 18, preferably SEQ ID NO: 17; and (b) a V λ -based sequence having one or two mutations, particularly one mutation, compared to the closest human V λ germline sequence of FW4, said FW4 comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 17 and SEQ ID NO: 18, preferably SEQ ID NO: 17.

In one embodiment, the variable light chain is identical to a light chain according to SEQ ID NO: 4, and/or wherein the variable heavy chain has at least 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% sequence identity to an amino acid sequence according to SEQ ID NO: 8 has at least 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity. In a specific embodiment, the variable light chain is identical to a light chain according to SEQ ID NO: 4, and/or wherein the variable heavy chain has at least 90% sequence identity to an amino acid sequence according to SEQ ID NO: 8 has at least 90% sequence identity.

Suitably, the present invention relates to an antibody or functional fragment thereof specific for human CD3, in particular human CD3 epsilon, comprising a variable light chain, wherein said variable light chain is identical to a light chain according to SEQ ID NO: 4, and wherein the variable light chain comprises arginine (R) or lysine (K), preferably arginine (R), at light chain amino acid position 54 (AHo numbering). In another embodiment, the variable light chain further comprises glutamine (Q) at light chain amino acid position 50 (AHo numbering) and/or serine (S) at light chain amino acid position 51 (AHo numbering), and optionally, phenylalanine (F) at light chain amino acid position 44 (AHo numbering) or glutamine (Q) at light chain amino acid position 88 (AHo numbering) or histidine (H) at light chain amino acid position 88 (AHo numbering). In a specific embodiment, the present invention relates to an antibody or functional fragment thereof specific for human CD3, in particular human CD3 epsilon, comprising a variable light chain, wherein said variable light chain is identical to a light chain according to SEQ ID NO: 4, and wherein the variable light chain comprises arginine (R) at light chain amino acid position 54 (AHo numbering), glutamine (Q) at light chain amino acid position 50 (AHo numbering), serine (S) at light chain amino acid position 51 (AHo numbering), and phenylalanine (F) at light chain amino acid position 44 (AHo numbering).

In another specific embodiment, the invention relates to an antibody or functional fragment thereof specific for human CD3, in particular human CD3 epsilon, comprising a variable light chain, wherein said variable light chain is identical to a light chain according to SEQ ID NO: 4, and wherein the variable light chain comprises arginine (R) at light chain amino acid position 54 (AHo numbering) and phenylalanine (F) at light chain amino acid position 44 (AHo numbering).

Suitably, in a specific embodiment, the present invention relates to an antibody or functional fragment thereof specific for human CD3, in particular human CD3 epsilon, comprising a variable heavy chain, wherein said variable heavy chain is identical to a light chain according to SEQ ID NO: 8, and wherein said variable heavy chain comprises at least one, e.g., at least two, preferably at least three, amino acids selected from the group consisting of: alanine (a) at heavy chain amino acid position 53 (AHo numbering), threonine (T) at heavy chain amino acid position 103 (AHo numbering), and phenylalanine (F) at heavy chain amino acid position 105 (AHo numbering). In one embodiment, the variable heavy chain is identical to a light chain according to SEQ ID NO: 8, and which comprises alanine (a) at heavy chain amino acid position 53 (AHo numbering), threonine (T) at heavy chain amino acid position 103 (AHo numbering), and phenylalanine (F) at heavy chain amino acid position 105 (AHo numbering).

In one embodiment, the invention relates to an antibody of the invention, or a functional fragment thereof, comprising a variable light chain comprising the amino acid sequence of SEQ ID NO: 4 or a conservatively modified variant thereof, said variable heavy chain comprising the amino acid sequence of SEQ ID NO: 8 or a conservatively modified variant thereof.

The term "conservatively modified variant" or "conservative variant" applies to both amino acid sequences and nucleic acid sequences. With respect to particular nucleic acid sequences, conservatively modified variants refers to those nucleic acids which encode identical or essentially identical amino acid sequences, or where the nucleic acid does not encode an amino acid sequence, to essentially identical sequences. Due to the degeneracy of the genetic code, a large number of functionally identical nucleic acids encode any given protein. For example, the codons GCA, GCC, GCG and GCU all encode the amino acid alanine. Thus, at each position where an alanine is specified by a codon, the codon can be changed to any of the corresponding codons described without changing the encoded polypeptide. Such nucleic acid variations are "silent variations," which are one of conservatively modified variations. Every nucleic acid sequence herein that encodes a polypeptide also describes every possible silent variation of the nucleic acid. The skilled artisan will recognize that each codon in a nucleic acid (except AUG, which is typically the only codon for methionine, and TGG, which is typically the only codon for tryptophan) can be modified to produce a functionally identical molecule. Thus, each silent variation of a nucleic acid encoding a polypeptide is implicit in each such sequence.

For polypeptide sequences, "conservatively modified variants" or "conservative variants" include individual substitutions, deletions or additions to the polypeptide sequence which result in the substitution of an amino acid with a chemically similar amino acid. Conservative substitution tables providing functionally similar amino acids are well known in the art. Such conservatively modified variants are in addition to, and do not exclude, polymorphic variants, interspecies homologs, and alleles of the invention. The following eight groups contain amino acids that are conservative substitutions for each other: 1) alanine (a), glycine (G); 2) aspartic acid (D), glutamic acid (E); 3) asparagine (N), glutamine (Q); 4) arginine (R), lysine (K); 5) isoleucine (I), leucine (L), methionine (M), valine (V); 6) phenylalanine (F), tyrosine (Y), tryptophan (W); 7) serine (S), threonine (T); and 8) cysteine (C), methionine (M) (see, e.g., Creighton, Protein (1984)). In one embodiment, the term "conservative sequence modification" is used to refer to amino acid modifications that do not significantly affect or alter the binding characteristics of an antibody containing the amino acid sequence.

In a preferred embodiment, the antibody or functional fragment thereof of the invention comprises a variable light chain comprising the amino acid sequence of SEQ ID NO: 4, and the variable heavy chain comprises the amino acid sequence of SEQ ID NO: 8.

In one embodiment of The invention, The isolated antibody or functional fragment thereof is selected from The group consisting of IgG Antibodies, Fab and scFv fragments.

Suitably, the antibody or functional fragment thereof of the invention is an scFv. In a specific embodiment, said functional fragment is a polypeptide comprising an amino acid sequence according to SEQ ID NO: 15, in the form of an scFv of the linker. Suitably, the antibody or functional fragment thereof of the invention is a scFv comprising a sequence selected from the group consisting of SEQ ID NOs: 4. 8, 29, 30, 32, 33, 35, 36, 37, 38, 39, 40, 41 and 42, or a pharmaceutically acceptable salt thereof. Suitably, the antibody or functional fragment thereof of the invention is an scFv comprising an amino acid sequence selected from the group consisting of: SEQ ID NO: 29. 30, 32, 33, 35, 36, 37, 38, 39, 40, 41 and 42.

As used herein, the term "affinity" refers to the strength of the sum of the total non-covalent interactions between an individual binding site or molecule (e.g., an antibody or functional fragment thereof) and its binding partner (e.g., an antigen). Unless otherwise indicated, the term "binding affinity" as used herein refers to a binding affinity that reflects a 1:1 interaction (e.g., interaction of a single antibody binding domain with its antigen)Affinity. Affinity can generally be determined by the dissociation constant (K)_D) And (4) showing. Affinity can be measured by common methods known in the art, including those described herein.

In suitable embodiments, the antibodies of the invention or functional fragments thereof may have a K with human CD3 and/or cynomolgus monkey CD3_DMay be between 0.1 to 100nM, 0.1 to 90nM, 0.1 to 80nM, 0.1 to 70nM, 0.1 to 60nM, 0.5 to 50nM, 0.5 to 40nM, 0.5 to 30nM, 0.5 to 20nM, 0.5 to 10nM, 0.5 to 9nM, 0.5 to 8nM, 0.5 to 7nM, 0.5 to 6nM, 0.5 to 5nM, in particular as measured by surface plasmon resonance. In suitable embodiments, the antibodies of the invention or functional fragments thereof may have a K with human CD3 and/or cynomolgus monkey CD3_DLess than about 100nM, less than about 90nM, less than about 80nM, less than about 70nM, less than about 60nM, less than about 55nM, less than about 40nM, less than about 45nM, less than about 40nM, less than about 35nM, less than about 30nM, less than about 25nM, less than 20nM, less than about 15nM, less than about 10nM, less than about 9nM, less than about 8nM, less than about 7nM, less than about 6nM, less than about 5nM, less than about 4nM, less than about 3nM, less than 2nM, less than 1nM, particularly as measured by surface plasmon resonance. Suitably, the antibody or functional fragment thereof of the invention is against K of human CD3 and/or cynomolgus monkey CD3_DLess than 10nM, preferably less than 6nM, particularly as measured by surface plasmon resonance.

In particular embodiments, the antibodies of the invention or functional fragments thereof are characterized by one or more of the following parameters:

(i) k binding to human CD3_DA value of less than 40nM, in particular less than 10nM, more in particular less than 6nM, in particular as measured by surface plasmon resonance; more particularly, as determined by the method shown in example 2.1;

(ii) k binding to cynomolgus monkey CD3_DA value of less than 20nM, in particular less than 10nM, more in particular less than 5nM, in particular as measured by surface plasmon resonance; more particularly, as determined by the method shown in example 2.1; and

(iii) when scFv (Single chain variable fragment)Fragment form) antibody form, as determined by Differential Scanning Fluorescence (DSF) as described previously (Egan et al, MAbs,9(1) (2017), 68-84; niesen, et al, Nature Protocols,2(9) (2007)2212-2221), in particular when the sample is diluted in five citrate phosphate buffers in the pH range of 3.5 to 7.5 and containing 0.15-0.25M NaCl, in particular 0.15M NaCl, the mean midpoint of its thermal unfolding temperature (Tm) is at least over 60 ℃, in particular at least 65 ℃, more in particular at least 68 ℃. The transition midpoint of the thermal unfolding of the scFv construct is the use of a fluorescent dyeOrange was determined by differential scanning fluorescence (see Wong)&Raleigh, Proteinscience 25(2016) 1834-. Samples were prepared under relevant excipient conditions by incorporation of a stock excipient prepared in the relevant buffer to give a final protein concentration of 50 μ g ml^-1. For the buffer exploration experiments, samples were loaded at different pH values (pH 3.4, 4.4, 5.4, 6.4 and 7.2) with final concentrations ofOrange final scFv buffer diluted to a total volume of 100 μ l. scFv DSF standards were measured as internal controls with unknown samples. 25 microliters of the prepared samples were added in triplicate to the white-wall AB gene PCR plate. The analysis was performed in a qPCR machine used as a thermal cycler and the fluorescence emission was detected using a custom dye calibration program for the software. The PCR plate containing the test sample was placed in a temperature ramp of 25 ℃ to 96 ℃ in 1 ℃ increments, with 30 seconds pause after each temperature increment. The total assay time was about two hours. Tm was calculated by GraphPad Prism software using the mathematical second derivative method to calculate the inflection point of the curve. The reported Tm is the average of three measurements. In a specific embodiment, the determination of Tm is performed as described in example 2.2, wherein the sample is diluted in citrate phosphate buffer pH 6.4 containing 0.25M NaCl.

In one aspect, the invention relates to a multispecific molecule, e.g., a bispecific, trispecific, tetraspecific, pentaspecific, hexaspecific or multivalent molecule, e.g., bivalent, trivalent, tetravalent, pentavalent, hexavalent molecule, comprising an antibody of the invention or a functional fragment thereof. In a specific embodiment, the multispecific molecule is a multispecific polypeptide. In a particular embodiment, the multivalent molecule is a multivalent polypeptide.

As used herein, the term "bispecific antibody" or "bispecific polypeptide" refers to an antibody that binds two different epitopes, in particular two different epitopes on two different targets. As used herein, the term "trispecific antibody" or "trispecific polypeptide" refers to an antibody that binds three different epitopes, in particular three different epitopes on three different targets.

The antibody or functional fragment thereof of the invention may be derivatized or linked to another functional molecule, such as another peptide or protein (e.g., another antibody or ligand of a receptor) to produce a multispecific molecule (e.g., multispecific polypeptide) that binds to at least two binding sites and/or to different target molecules. Indeed, the antibodies of the invention may be derivatized or linked to more than one other functional molecule to produce multispecific molecules (e.g., multispecific polypeptides) that bind to more than two different binding sites and/or target molecules. To produce a multispecific molecule of the invention, an antibody of the invention may be functionally linked (e.g., by chemical coupling, genetic fusion, non-covalent binding, or otherwise) to one or more other binding molecules, such as another antibody, antibody fragment, peptide, or binding mimetic, to produce a multispecific molecule.

In one embodiment, the multispecific polypeptide of the invention comprises: (a) an antibody of the invention, or a functional fragment thereof, and (b) at least one binding domain that binds to a target other than CD 3.

As used herein, the terms "binding domain", "antigen-binding fragment thereof", "antigen-binding portion" or "functional fragment" of an antibody, and the like, refer to one or more fragments of an intact antibody that retains the ability to specifically bind to a particular antigen (e.g., CD3, IL23R, HER2, HSA)Force. The antigen binding function of an antibody may be performed by a fragment of an intact antibody. In some embodiments, the binding domain of the multispecific antibodies of the present invention is selected from the group consisting of: fab fragments, monovalent fragments consisting of the VL, VH, CL and CH1 domains; f (ab')₂A fragment, a bivalent fragment comprising two Fab fragments linked by a disulfide bond at the hinge region; (ii) a fragment of Fd consisting of VH and CHI domains; (ii) an Fv fragment consisting of the VL and VH domains of a single arm of an antibody; single domain antibody (dAb) fragments consisting of VH domains (Ward et al, 1989Nature 341: 544-546); isolated Complementarity Determining Regions (CDRs), dsfvs, scabs, STABs, single domain antibodies (sdabs or dabs), single domain heavy and light chain antibodies, VHHs, VNARs, single domain antibodies based on VNAR structures from sharks, and binding domains based on other scaffolds including, but not limited to, ankyrin-based domains, fynomers, avimers, mimobodies (anticalins), fibronectin, and binding sites constructed into the constant region of an antibody (e.g., f-star technology). Suitably, the binding domain of the invention is a single chain Fv fragment (scFv) or a single antibody variable domain. In a preferred embodiment, the binding domain of the invention is a single chain Fv fragment (scFv).

Suitably, the multispecific polypeptide of the invention comprises: (a) an antibody of the invention, or a functional fragment thereof, and (b) at least one, preferably one, Tumor Associated Antigen (TAA) binding domain.

In one embodiment, the multispecific polypeptide of the invention comprises: (a) an antibody of the invention or a functional fragment thereof, and (b) at least one, preferably one, IL23R binding domain.

Interleukin (IL) -23 is a heterodimeric cytokine consisting of two protein subunits designated p40 and p19 due to their approximate molecular weights. The p40 protein is shared between IL-12 and IL-23, while the p19 protein subunit is specific for IL-23. IL-23 signals through a two-chain receptor complex consisting of an IL-12 receptor beta-1(IL-12R β 1) chain that binds p40 and a unique IL-23 receptor chain (IL23R) that confers IL-23 specific intracellular signaling. The term "IL 23R" especially refers to human IL23R with UniProt ID number Q5VWK 5.

In some embodiments, the IL23R binding domain is derived from a monoclonal antibody or antibody fragment.

Suitable IL23R binding domains are specific for human IL23R and include: a variable light chain and a variable heavy chain, wherein the variable light chain comprises, from N-terminus to C-terminus, the regions LFW1-LCDR1-LFW2-LCDR2-LFW3-LCDR3-LFW4, wherein each LFW represents a light chain framework region and each LCDR represents a light chain complementarity determining region, and wherein the LCDRs are together with a light chain complementarity determining region taken from the group consisting of SEQ ID NO: 11 has at least 90% sequence identity to the corresponding LCDR; wherein the variable heavy chain comprises, from N-terminus to C-terminus, the regions HFW1-HCDR1-HFW2-HCDR2-HFW3-HCDR3-HFW4, wherein each HFW represents a heavy chain framework region and each HCDR represents a heavy chain complementarity determining region, and wherein the HCDRs together are selected from the group consisting of SEQ ID NOs: the corresponding HCDR of the VH sequence of 12 has at least 90% sequence identity. Suitably, the IL23R binding domain of the invention comprises (i) a sequence as taken from SEQ ID NO: 11, LCDR1, LCDR2, LCDR3 as shown in the corresponding CDR regions of the VL sequence according to SEQ ID NO: 12, HCDR1, HCDR2, HCDR3 as shown in the corresponding CDR regions of the VH sequence of fig. 12.

In one embodiment, the variable light chain of the IL23R binding domain has a sequence according to SEQ ID NO: 11, and/or the variable heavy chain of said IL23R binding domain shares at least 90% sequence identity with the amino acid sequence according to seq id NO: 12 has at least 90% sequence identity. In a specific embodiment, the IL23R binding domain of the invention comprises: (i) and a polypeptide according to SEQ ID NO: 11, wherein the variable light chain comprises a variable light chain having at least 90% sequence identity as taken from the amino acid sequence according to seq id NO: 11, LCDR1, LCDR2, LCDR3 and/or (ii) a CDR sequence according to SEQ ID NO: 12, wherein the variable heavy chain comprises a variable light chain having at least 90% sequence identity to the amino acid sequence according to SEQ ID NO: 12, HCDR1, HCDR2, HCDR3 as shown in the corresponding CDR regions of the VH sequence. In a specific embodiment, the variable light chain of the IL23R binding domain comprises an amino acid sequence according to SEQ ID NO: 11, or a conservatively modified variant thereof, and/or the variable heavy chain of said IL23R binding domain comprises an amino acid sequence according to SEQ ID NO: 12 or conservatively modified variants thereof. In a more specific embodiment, the variable light chain of said IL23R binding domain comprises an amino acid sequence according to SEQ ID NO: 11, and/or the variable heavy chain of said IL23R binding domain comprises an amino acid sequence according to SEQ ID NO: 12.

In a specific embodiment, said IL23R binding domain is a polypeptide comprising an amino acid sequence according to SEQ ID NO: 15, in the form of an scFv of the linker.

In one embodiment, the multispecific polypeptide of the invention comprises: (a) an antibody of the invention, or a functional fragment thereof, and (b) at least one IL23R binding domain, and wherein the multispecific polypeptide comprises an amino acid sequence that differs from the amino acid sequence of seq id NO: 26, preferably wherein said multispecific polypeptide comprises an amino acid sequence having at least 60%, 70%, 80%, 90% identity according to SEQ ID NO: 26.

In one embodiment, the multispecific polypeptide of the invention comprises: (a) an antibody of the invention or a functional fragment thereof, and (b) at least one, preferably one, HER2 binding domain.

The term "HER 2" particularly refers to human HER2 having the UniProt ID number Q5VWK 5.

In some embodiments, the HER2 binding domain is derived from a monoclonal antibody or antibody fragment.

Suitable HER2 binding domains are specific for human HER2 and include: a variable light chain and a variable heavy chain, wherein the variable light chain comprises, from N-terminus to C-terminus, the regions LFW1-LCDR1-LFW2-LCDR2-LFW3-LCDR3-LFW4, wherein each LFW represents a light chain framework region and each LCDR represents a light chain complementarity determining region, and wherein the LCDRs are together with a light chain complementarity determining region taken from the group consisting of SEQ ID NO: 20 has at least 90% sequence identity to the corresponding LCDR; wherein the variable heavy chain comprises, from N-terminus to C-terminus, the regions HFW1-HCDR1-HFW2-HCDR2-HFW3-HCDR3-HFW4, wherein each HFW represents a heavy chain framework region and each HCDR represents a heavy chain complementarity determining region, and wherein the HCDRs together are selected from the group consisting of SEQ ID NOs: the corresponding HCDR of the VH sequence of 21 has at least 90% sequence identity. Suitably, the HER2 binding domain of the invention comprises (i) a sequence as taken from SEQ ID NO: 20, LCDR1, LCDR2, LCDR3 as shown in the corresponding CDR regions of the VL sequence according to SEQ ID NO: 21, HCDR1, HCDR2, HCDR3 as shown in the corresponding CDR regions of the VH sequence.

In one embodiment, the variable light chain of HER2 binding domain hybridizes to a sequence according to SEQ ID NO: 20, and/or the variable heavy chain of HER2 binding domain shares at least 90% sequence identity with the amino acid sequence according to SEQ id no: 21 has at least 90% sequence identity. In a specific embodiment, the HER2 binding domain of the invention comprises: (i) and a polypeptide according to SEQ ID NO: 20, wherein the variable light chain comprises a variable light chain having at least 90% sequence identity as taken from the amino acid sequence according to SEQ ID NO: 20, LCDR1, LCDR2, LCDR3 and/or (ii) a CDR sequence according to SEQ ID NO: 21, wherein the variable heavy chain comprises a variable light chain having at least 90% sequence identity to the amino acid sequence according to SEQ ID NO: 21, HCDR1, HCDR2, HCDR3 as shown in the corresponding CDR regions of the VH sequence. In a specific embodiment, the variable light chain of HER2 binding domain comprises an amino acid sequence according to SEQ ID NO: 20, or a conservatively modified variant thereof, and/or the variable heavy chain of said HER2 binding domain comprises an amino acid sequence according to SEQ ID NO: 21 or a conservatively modified variant thereof. In a more specific embodiment, the variable light chain of HER2 binding domain comprises an amino acid sequence according to SEQ ID NO: 20, and/or the variable heavy chain of said HER2 binding domain comprises an amino acid sequence according to SEQ ID NO: 21.

In a specific embodiment, the HER2 binding domain is a polypeptide comprising an amino acid sequence according to SEQ ID NO: 15, in the form of an scFv of the linker.

In a specific embodiment, the HER2 binding domain of the invention is trastuzumab or a functional fragment thereof. In one embodiment, the multispecific polypeptide of the invention comprises: (a) an antibody of the invention, or a functional fragment thereof, and (b) at least one HER2 binding domain, and wherein the multispecific polypeptide comprises an amino acid sequence that differs from the amino acid sequence of SEQ ID NO: 27, preferably wherein said multispecific polypeptide comprises an amino acid sequence having at least 60%, 70%, 80%, 90% identity according to SEQ ID NO: 27.

In another embodiment, the multispecific polypeptide of the invention may comprise another binding domain specific to human serum albumin. In one embodiment, the multispecific polypeptide of the invention comprises: (a) an antibody of the invention or a functional fragment thereof, (b) at least one, preferably one, IL23R binding domain and (c) at least one, preferably one, HSA binding domain. In one embodiment, the multispecific polypeptide of the invention comprises: (a) an antibody of the invention or a functional fragment thereof, (b) at least one, preferably one, HER2 binding domain and (c) at least one, preferably one, HSA binding domain.

The term "HSA" especially refers to human serum albumin or variants thereof with UniProt ID number P02768. Human Serum Albumin (HSA) is a 66.4kDa abundant Protein in human serum (50% of total Protein) consisting of 585 amino acids (Sugio, Protein Eng, Vol.12, 1999, 439-. Multifunctional HSA proteins are associated with structures that allow for the binding and transport of many metabolites, such as fatty acids, metal ions, bilirubin, and certain drugs (Fanali, Molecular assays of Medicine, vol.33,2012, 209-290). The concentration of HSA in serum is about 3.5-5 g/dL. Antibodies and fragments thereof that bind albumin can be used, for example, to extend the in vivo serum half-life of drugs or proteins bound thereto.

In some embodiments, the HSA binding domain is derived from a monoclonal antibody or antibody fragment.

Suitable HSA binding domains for use in the multispecific polypeptides of the present invention are the binding domains provided in the present disclosure. The HSA binding domains of the invention include, but are not limited to, the humanized monoclonal antibodies listed in table 1.

Suitable HSA binding domains are specific for human HSA and comprise: a variable light chain and/or a variable heavy chain that is identical to a variable light chain according to SEQ ID NO: 22, wherein the variable heavy chain has at least 90% sequence identity to an amino acid sequence according to SEQ ID NO: 23 has at least 90% sequence identity. In a specific embodiment, the HSA binding domain of the invention comprises: (i) and a polypeptide according to SEQ ID NO: 22, wherein the variable light chain comprises a variable light chain having at least 90% sequence identity to the amino acid sequence according to SEQ ID NO: 22, LCDR1, LCDR2, LCDR3 and/or (ii) a CDR sequence corresponding to the CDR regions of the VL sequence according to SEQ ID NO: 23, wherein the variable heavy chain comprises a variable region having at least 90% sequence identity to the amino acid sequence according to SEQ ID NO: HCDR1, HCDR2, HCDR3 shown in the corresponding CDR regions of the VH sequence of 23. In a more specific embodiment, the variable light chain of the HSA binding domain comprises a sequence according to SEQ ID NO: 22, and/or the variable heavy chain of the HSA binding domain comprises an amino acid sequence according to SEQ ID NO: 23. Another suitable HSA binding domain is specific for human HSA and comprises: a variable light chain and/or a variable heavy chain that is identical to a variable light chain according to SEQ ID NO: 24, wherein the variable heavy chain has at least 90% sequence identity to an amino acid sequence according to SEQ ID NO: 25 has at least 90% sequence identity. In a specific embodiment, the HSA binding domain of the invention comprises: (i) and a peptide according to SEQ id no: 24, wherein the variable light chain comprises a variable light chain having at least 90% sequence identity as taken from the amino acid sequence according to SEQ ID NO: LCDR1, LCDR2, LCDR3 and/or (ii) the corresponding CDR regions of the VL sequence of 24 and the amino acid sequence according to SEQ ID NO: 25, wherein the variable heavy chain comprises a variable region having at least 90% sequence identity to the amino acid sequence according to SEQ ID NO: 25, HCDR1, HCDR2, HCDR3 as shown in the corresponding CDR regions of the VH sequence. In a specific embodiment, the variable light chain of the HSA binding domain comprises a sequence according to SEQ ID NO: 24 or conservatively modified variants thereof, and/or the variable heavy chain of said HSA binding domain comprises an amino acid sequence according to SEQ ID NO: 25 or a conservatively modified variant thereof. In a more specific embodiment, the variable light chain of the HSA binding domain comprises a sequence according to SEQ ID NO: 24, and/or the variable heavy chain of the HSA binding domain comprises the amino acid sequence according to seq id NO: 25.

In a specific embodiment, the HSA binding domain is a polypeptide comprising an amino acid sequence according to SEQ ID NO: 15, in the form of an scFv of the linker.

Suitably, the multispecific polypeptide of the invention is in the form of an antibody selected from any suitable multispecific (e.g. bispecific) form known in the art, including but not limited to forms based on: single chain bifunctional antibodies (scDb), tandem scDb (tandab), linear dimer scDb (LD-scDb), cyclic dimer scDb (CD-scDb), bispecific T cell engagers (BITE; tandem di-scFv), tandem tri-scFv, triabodies (Fab- (scFv)₂) Or diabodies (Fab- (scFv)₁)、Fab、Fab-Fv₂Morrison (IgGCH3-scFv fusion (Morrison L) or IgG CL-scFv fusion (Morrison H)), trifunctional antibodies (triabody), scDb-scFv, bispecific Fab₂A diabody, a tetrabody, a scFv-Fc-scFv fusion, a diabody, a DVD-Ig, COVD, IgG-scFab, scFab-dsscFv, Fv₂Fc, IgG-scFv fusions, such as bsAb (scFv linked to the C-terminus of the light chain), Bs1Ab (scFv linked to the N-terminus of the light chain), Bs2Ab (scFv linked to the N-terminus of the heavy chain), Bs3Ab (scFv linked to the C-terminus of the heavy chain), Ts1Ab (scFv linked to the N-termini of the heavy and light chains), Ts2Ab (dsscFv linked to the C-terminus of the heavy chain) and Knob-into-Hole antibody (KiHs) (bispecific IgG made by the KiH technique), MATCH (described in WO 2016/0202457; EganT et al, mAbs 9(2017)68-84) and DuoBodies (bispecific IgG made by the Duobody technique) (MAbs.2017Feb/Mar; 9(2):182-212.doi: 10.1080/19420862.2016.1268307). Particularly suitable for use herein are single chain bifunctional antibodies (scDb), in particular bispecific monomeric scDb, or scDb-scFv, in particular trispecific monomeric scDb-scFv.

The term "bifunctional antibody" refers to an antibody fragment having two antigen-binding sites, which fragment comprises a VH (VH-VL) linked to a VL in the same polypeptide chain. By using linkers that are too short to allow pairing between the two domains on the same chain, these domains are forced to pair with the complementary domains of the other chain to create two antigen binding sites. Bifunctional antibodies may be bivalent or bispecific. Diabodies are described more fully in, for example, EP404097, WO1993/01161, Hudson et al, nat. Med.9: 129-64134 (2003) and Hollinger et al, Proc. Natl. Acad. Sci. USA 90:6444-6448 (1993). Tri-and tetra-functional antibodies are also described in Hudson et al, nat. Med.9:129-134 (2003).

A bispecific scDb, in particular a bispecific monomeric scDb, in particular comprising two variable heavy chain domains (VH) or fragments thereof and two variable light chain domains (VL) or fragments thereof, which are connected in the following order by a linker L1, L2 and L3: VHA-L1-VLb-L2-VLA, VHA-L1-VL2-L2-VLA, VLA-L1-VL 2-L2-LB-L3-L3-VHA, VHb-L1-VLA-L2-VHA-L3-VLB, VHB-L1-VHA-L2-VLA-L3-VLB, VLB-L1-VLA-L2-VHA-L3-VLB or VLB-L1-VHA-L2-VLA-L3-VHB, wherein the VLA and VHA domains together form an antigen binding site for a first antigen and the VLB and VHB together form an antigen binding site for a second antigen.

Linker L1 is in particular a 2-10 amino acid peptide, more in particular 3-7 amino acids, most in particular 5 amino acids, and linker L3 is in particular a 1-10 amino acid peptide, more in particular 2-7 amino acids, most in particular 5 amino acids. In a specific embodiment, L1 and L3 are both GGGGS (SEQ ID NO: 16). The intermediate linker L2 is in particular a peptide of 10-40 amino acids, more in particular 15-30 amino acids, most in particular 20-25 amino acids. In a specific embodiment, L2 is (GGGGS)₄(SEQID NO：15)。

In one embodiment of the invention, the multispecific polypeptide comprising an antibody or functional fragment thereof of the invention is a multispecific and/or multivalent antibody in the form of a MATCH described in WO 2016/0202457; egan t, et al, mAbs 9(2017) 68-84.

Bispecific, bivalent, multispecific, and/or multivalent constructs of the invention can be produced using any convenient antibody preparation method known in the art. (in connection with the generation of the bispecific construct,see, e.g., Fischer, N.&Leger, o., Pathobiology 74(2007) 3-14; for bispecific diabodies and tandem scFv Hornig, N.&

Schwarz, A., Methods mol.biol.907(2012)713-727, and WO 99/57150). Specific examples of suitable methods for preparing the bispecific constructs of the invention also include, inter alia, Genmab (see Labrijn et al, Proc. Natl. Acad. Sci. USA 110(2013) 5145-. Methods for generating bispecific antibodies comprising a functional antibody Fc portion are also known in the art (see, e.g., Zhu et al, Cancer Lett.86(1994) 127-; and Suresh et al, Methods enzymol.121(1986) 210-.

These methods generally involve the generation of monoclonal antibodies, for example by fusing myeloma cells with mouse spleen cells that have been immunized with the desired antigen using hybridoma technology (see, e.g., Yokoyama et al, curr. protocol. immunol. chapter 2, Unit 2.5,2006), or by recombinant antibody engineering techniques (library cloning or phage display/yeast display) (see, e.g., chapes & Baty, FEMS microbiol. letters189(2000)1-8), as well as the combination of antigen binding domains of two different monoclonal antibodies, or fragments or portions thereof, to yield bispecific constructs using known molecular cloning techniques.

In particular embodiments, the multispecific polypeptide further comprises one or more polypeptide linkers.

In a specific embodiment, the multispecific polypeptide is a monomeric polypeptide, in particular, a monomeric polypeptide, wherein the antibody or functional fragment thereof according to the invention is an scFv antibody fragment linked to a second binding domain by a linker, in particular, wherein the second binding domain is a second scFv antibody fragment.

In a specific embodiment, the multispecific polypeptide is a dimeric polypeptide, in particular, a dimeric polypeptide in which the binding of two polypeptides is caused by the binding of complementary VL and VH domains of an antibody fragment comprised in the multispecific polypeptide. In particular such embodiments, the multispecific polypeptide is a multispecific antibody construct according to the teachings of WO 2016/202457. In a specific other embodiment, the multispecific polypeptide is a single chain bifunctional antibody construct (scDb). In specific other embodiments, the multispecific polypeptide is a Fab- (scFv)_nConstructs (n is an integer selected from 1, 2,3 or 4) assembled with heterodimers of Fab fragments consisting of VL-CL and VH-CH1, wherein either constant domain forms the backbone, wherein one or more scFv fragments are linked to the scaffold by a flexible linker.

In a third aspect, the present invention relates to a pharmaceutical composition comprising an antibody or a functional fragment thereof of the present invention or a multispecific polypeptide of the present invention, and a pharmaceutically acceptable carrier and/or excipient.

The phrase "pharmaceutically acceptable" refers to those compounds, materials, compositions, and/or dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings or animals without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit/risk ratio.

The pharmaceutical compositions according to the invention may further conventionally comprise pharmaceutically acceptable concentrations of salts, buffers, preservatives, supplemental immunopotentiators (e.g. adjuvants and cytokines) and optionally other therapeutic agents. The composition may further comprise an antioxidant and/or a preservative. As the antioxidant, thiol derivatives (e.g., thioglycerol, cysteine, acetylcysteine, cystine, dithioerythritol, dithiothreitol, glutathione), tocopherol, butylhydroxyanisole, butylhydroxytoluene, sulfites (e.g., sodium sulfate, sodium bisulfite, acetone sodium bisulfite, sodium metabisulfite, sodium sulfite, sodium formaldehyde sulfoxylate, sodium thiosulfate), and nordihydroguaiaretic acid may be mentioned. Suitable preservatives may be, for example, phenol, chlorobutanol, benzyl alcohol, methyl paraben, propyl paraben, benzalkonium chloride and cetylpyridinium chloride.

In particular embodiments provided herein, the antibodies or functional fragments thereof may be isolated, produced, expressed or produced by recombinant means, such as antibodies expressed using recombinant expression vectors transfected into host cells, antibodies isolated from recombinant combinatorial antibody libraries, or by any other means involving, for example, synthetic production, genetic engineering of DNA sequences encoding human immunoglobulin sequences, or splicing of sequences encoding human immunoglobulins (e.g., human immunoglobulin gene sequences) to other such sequences.

Thus, in a fourth aspect, the invention relates to a nucleic acid sequence or a collection of nucleic acid sequences encoding an antibody or a functional fragment thereof according to the invention.

The term "nucleic acid" is used interchangeably herein with the term "polynucleotide" and refers to deoxyribonucleotides or ribonucleotides and polymers thereof in either single-or double-stranded form. The term includes nucleic acids containing known nucleotide analogs or modified backbone residues or linkages (links), which are synthetic, naturally occurring, and non-naturally occurring, which have similar binding properties as standard nucleic acids and are metabolized in a manner similar to standard nucleotides. Examples of such analogs include, but are not limited to, phosphorothioate, phosphoramidate, methylphosphonate, chiral methylphosphonate, 2-O-methyl ribonucleotide, Peptide Nucleic Acid (PNA). Unless otherwise indicated, a particular nucleic acid sequence also implicitly includes conservatively modified variants thereof (e.g., degenerate codon substitutions) and complementary sequences, as well as the sequence explicitly indicated. Specifically, degenerate codon substitutions may be achieved by generating sequences in which the third position of one or more selected (or all) codons is substituted with mixed-base and/or deoxyinosine residues, as described below (Batzer et al, Nucleic Acid Res.19:5081,1991; Ohtsuka et al, J.biol.chem.260: 2605. sup. 2608; 1985; and Rossolini et al, mol.cell. Probes 8:91-98,1994).

In a fifth aspect, the invention relates to a vector or collection of vectors comprising a nucleic acid sequence or collection of nucleic acid sequences of the invention. The term "vector" or "expression vector" refers to a polynucleotide, most commonly a DNA plasmid, comprising a nucleotide sequence encoding an antibody or fragment thereof of the present invention for recombinant expression in a host cell, preferably a mammalian cell. The vector may or may not replicate in the cell. Once the polynucleotides encoding the variable heavy and/or variable light chains of the antibodies described herein, or fragments thereof, are obtained, vectors for producing the antibody molecules can be produced by recombinant DNA techniques using techniques well known in the art. Thus, described herein are methods for producing proteins by expressing polynucleotides comprising antibody-encoding nucleotide sequences. Methods well known to those skilled in the art can be used to construct expression vectors containing antibody coding sequences and appropriate transcriptional and translational control signals. These methods include, for example, in vitro recombinant DNA techniques, synthetic techniques, and in vivo genetic recombination.

The expression vector can be transferred to a host cell by conventional techniques, and the resulting cell can then be cultured by conventional techniques to produce the antibody or fragment thereof described herein. Thus, the present invention relates to a host cell, in particular an expression host cell, comprising a nucleic acid sequence or a collection of nucleic acid sequences of the present invention, or a vector or a collection of vectors of the present invention. In certain embodiments, the host cell comprises a vector comprising a polynucleotide encoding both the variable heavy chain and the variable light chain of an antibody or fragment thereof of the invention. In a specific embodiment, the host cell contains two different vectors, a first vector comprising a polynucleotide encoding the variable heavy chain of said antibody or a fragment thereof, and a second vector comprising a polynucleotide encoding the variable light chain of said antibody or a fragment thereof. In other embodiments, the first host cell comprises a first vector comprising a polynucleotide encoding the variable heavy chain of the antibody or a fragment thereof, and the second host cell comprises a second vector comprising a polynucleotide encoding the variable light chain of the antibody or a functional fragment thereof.

Methods of humanizing Rabbit or rodent antibodies are well known to those of ordinary skill in The art (see, e.g., Borras, J Biol chem.2010Mar 19; 285(12): 9054-66; radior et al, The FASEBjournal, expressary 10.1096/fj.02-0281fje, published online October 18,2002; Yu et al (2010) A Humanized Anti-VEGF Rabbit Monoclonal Antibody inhibiting induction and Blocks Tumor Growth in xeno models. PLoS ONE 5(2): e9072.doi: 10.1371/journer. pore. 0009072). Immunization of rabbits or rodents may be performed with the antigen of interest itself, e.g., a protein, or, in the case of a peptide or protein antigen, by immunizing the DNA of a rabbit with a nucleic acid (e.g., a plasmid) encoding the peptide or protein of interest.

In a sixth aspect, the present invention relates to a host cell, in particular an expression host cell, comprising a nucleic acid sequence or a collection of nucleic acid sequences of the present invention, or a vector or a collection of vectors of the present invention.

The term "host cell" refers to a cell into which an expression vector has been introduced. It should be understood that these terms are not intended to refer to a particular subject cell, but to the progeny of such a cell. Because certain modifications may occur in succeeding generations due to either mutation or environmental influences, such progeny may not, in fact, be identical to the parent cell, but are still included within the scope of the term "host cell" as used herein.

In a seventh aspect, the invention relates to a method for producing an antibody or a functional fragment thereof of the invention, comprising the step of expressing a nucleic acid sequence or a collection of nucleic acid sequences of the invention, or a vector or a collection of vectors of the invention, or a host cell of the invention, in particular an expression host cell.

In an eighth aspect, the present invention relates to a method of producing a multispecific construct comprising the step of cloning in one or more steps one or more nucleic acid sequences encoding an antibody or functional fragment thereof according to the present invention into a multispecific construct comprising a nucleic acid sequence encoding at least a second binding domain or fragment thereof and optionally, a nucleic acid sequence encoding one or more additional binding domains or fragments thereof.

In a specific embodiment of the eighth aspect, the second binding domain is a second antibody or a functional fragment thereof.

In a specific embodiment, at least one of said optional further binding domains is present, in particular wherein said further binding domain is a third antibody or a functional fragment thereof.

In another aspect, the invention relates to an antibody or functional fragment thereof of the invention, or a multispecific polypeptide comprising an antibody or functional fragment thereof of the invention, or a composition of the invention, for use as a medicament.

In another aspect, the invention relates to an antibody or functional fragment thereof of the invention, or a multispecific polypeptide comprising an antibody or functional fragment thereof of the invention, or a composition of the invention, for use in the manufacture of a medicament.

In one aspect, the invention relates to an antibody or functional fragment thereof of the invention, or a multispecific polypeptide comprising an antibody or functional fragment thereof of the invention, or a composition of the invention, for use in treating cancer, inflammatory and/or autoimmune disease in a subject in need thereof.

In another aspect, the invention relates to the use of an antibody or functional fragment thereof of the invention, or a multispecific polypeptide comprising an antibody or functional fragment thereof of the invention, or a composition of the invention, to treat cancer, inflammatory and/or autoimmune disease in a subject in need thereof.

In another aspect, the invention relates to the use of an antibody or functional fragment thereof of the invention, or a multispecific polypeptide comprising an antibody or functional fragment thereof of the invention, or a composition of the invention, in the manufacture of a medicament for treating cancer, an inflammatory and/or an autoimmune disease in a subject in need thereof.

In one aspect, the present invention relates to a method of treating cancer, inflammatory and/or autoimmune disease in a subject in need thereof, comprising administering to said subject a therapeutically effective amount of an antibody or functional fragment thereof of the present invention, or a multispecific polypeptide comprising an antibody or functional fragment thereof of the present invention, or a composition of the present invention.

The term "subject" includes both human and non-human animals. Non-human animals include all vertebrates (e.g., mammals and non-mammals (e.g., non-human primates, sheep, dogs, cows, chickens)), amphibians, and reptiles. The terms "patient" or "subject" are used interchangeably herein, unless otherwise indicated.

As used herein, the terms "treatment", "treating", and the like refer to obtaining a desired pharmacological and/or physiological effect. The effect may be therapeutic in terms of a partial or complete cure of the disease and/or adverse effects on the disease or delay of disease progression. As used herein, "treatment" encompasses any treatment of a disease in a mammal, such as a human, and includes: (a) inhibiting the disease, i.e. arresting its development; (c) alleviate the disease, i.e., resolve the disease.

The term "therapeutically effective amount" or "effective amount" refers to an amount of an agent that, when administered to a mammal or other subject to treat a disease, is sufficient to effect such treatment for the disease. The "therapeutically effective amount" will vary depending on the agent, disease and its severity and age, weight, etc., of the subject to be treated.

The inflammatory and/or autoimmune disease may be rheumatoid arthritis, ankylosing spondylitis, psoriasis, psoriatic arthritis, ulcerative colitis, crohn's disease, systemic lupus erythematosus, juvenile diabetes, autoimmune uveitis and multiple sclerosis, parkinson's disease, alzheimer's disease, and ischemia reperfusion injury.

The term "cancer" refers to a disease characterized by rapid and uncontrolled growth of abnormal cells. Cancer cells can spread locally, but also to other parts of the body through the blood and lymphatic system. The terms "tumor" and "cancer" are used interchangeably herein, e.g., both terms encompass both solid and liquid, such as a disseminated or circulating tumor. As used herein, the term "cancer" or "tumor" includes pre-malignant as well as malignant cancers and tumors.

Cancers to be treated include, but are not limited to, colorectal cancer, lung cancer, breast cancer, nasopharyngeal cancer, oral cancer, esophageal cancer, pancreatic cancer, B-cell lymphoma, and T-cell lymphoma, including adult T-cell lymphoma leukemia (ATLL), Acute Myeloid Lymphoma (AML), diffuse large B-cell lymphoma (DLBCL), Follicular Lymphoma (FL), pediatric acute lymphoblastic lymphoma (B-ALL), angioimmunoblastic T-cell lymphoma (AITL), Anaplastic Large Cell Lymphoma (ALCL), T/natural killer cell lymphoma, and peripheral T-cell lymphoma (PTCL). In particular embodiments, the cancer is selected from colorectal cancer, lung cancer, breast cancer, nasopharyngeal cancer, oral cancer, esophageal cancer, B-cell lymphoma, and T-cell lymphoma, such as adult T-cell lymphoma leukemia (ATLL), angioimmunoblastic T-cell lymphoma (AITL), anaplastic large-cell lymphoma (ALCL), T/natural killer cell lymphoma, and peripheral T-cell lymphoma (PTCL).