Patent Description:
Gangliosides are a family of glycolipids and are composed of a sugar chain portion and a lipid (ceramide: fatty acid + long-chain base). Gangliosides are synthesized by a series of enzymatic reactions and metabolized to end products. GD2 is synthesized from GD3 by GM2/GD2 synthase, and further synthesized to GD1b by GM1/GD1b/GA1 synthase.

In cancer cells, the expression of GD2 synthase is high, and the expression of GD1b synthase is low, resulting in high GD2 expression on the cell surface. It is known that GD2 expressed on cells is involved in cell adhesion and signal transduction by coexisting with adhesion molecules such as integrins and is involved in cancer growth and metastasis.

GD2 is known to be highly expressed in melanoma, neuroblastoma, glioblastoma, lung cancer, osteosarcoma, and leukemia. GD2 is expressed in nerve cells and glial cells in normal tissues, but its expression in these normal tissues is low.

Because GD2 is considered to be a good molecule target, antibodies that recognize GD2 have been isolated and used in antibody treatment or CAR treatment (PTL <NUM>). However, the treatments have limited effects so far, showing insufficient therapeutic efficacy. For example, as shown in <FIG> of PTL <NUM>, cytotoxic action in vitro is weak, and the treatment on P1143 shows about <NUM>% lysis (effector-to-target ratio: <NUM>:<NUM>), which was the most potent effect, while showing only about a few percent for others. PTL <NUM> also discloses that melanoma was injected through IV to develop lung cancer, followed by effector infusion (<NUM>×<NUM><NUM>) (<FIG>), and <FIG>% of mice were dead on day <NUM>, showing that the therapeutic experiment did not achieve a complete cure.

An object of the present invention is to provide a cancer treatment or prevention technique that molecularly targets GD2.

The present inventors conducted extensive research in view of the problem above and found that the problem can be solved by a chimeric antigen receptor comprising a GD2-binding domain comprising a heavy-chain variable region containing a heavy-chain CDR1 containing the amino acid sequence represented by SEQ ID NO: <NUM>, a heavy-chain CDR2 containing the amino acid sequence represented by SEQ ID NO: <NUM>, and a heavy-chain CDR3 containing the amino acid sequence represented by SEQ ID NO: <NUM>, and a light-chain variable region containing a light-chain CDR1 containing the amino acid sequence represented by SEQ ID NO: <NUM>, a light-chain CDR2 containing the amino acid sequence represented by SEQ ID NO: <NUM>, and a light-chain CDR3 containing the amino acid sequence represented by SEQ ID NO: <NUM>. The inventors conducted further research on the basis of this finding and completed the present invention. Specifically, the present invention includes the following subject matter. The present invention relates to the object defined in claim <NUM>. In one embodiment, the chimeric antigen receptor is characterized by its binding ability as defined in claim <NUM>. In another embodiment, the chimeric antigen receptor is characterized by its core domain as defined in claims <NUM> and <NUM>. In another embodiment, the chimeric antigen receptor a GITRL domain as defined in claim <NUM>. The present invention relates also to a polynucleotide as defined in claim <NUM>. The present invention relates also to a cell comprising the polynucleotide as defined in claim <NUM>. The present invention relates also to a chimeric antigen receptor T-cell or NK-cell as defined in claim <NUM>. The present invention relates to a pharmaceutical composition as defined in claims <NUM> and <NUM>.

The present invention provides a technique of treating or preventing cancer that molecularly targets GD2. Specifically, the present invention treats or prevents cancer by using a chimeric antigen receptor that molecularly targets GD2.

In the present specification, the terms "comprising," "containing," and "including" include the concepts of comprising, containing, consisting essentially of, and consisting of.

The "identity" of amino acid sequences refers to the degree to which two or more contrastable amino acid sequences match each other. Thus, the higher the degree of match between two amino acid sequences, the higher the identity or similarity of those sequences. The level of amino acid sequence identity is determined, for example, by using FASTA (a tool for sequence analysis) with default parameters. Alternatively, the level of amino acid sequence identity can be determined by using the BLAST algorithm by Karlin and Altschul (<NPL>), <NPL>)). A program called "BLASTX," based on this BLAST algorithm, has been developed. The specific techniques of these analysis methods are known and can be found on the website of the National Center of Biotechnology Information (NCBI) (http://www. The "identity" of base sequences is also defined in the same manner as above.

In the present specification, "conservative substitution" means the substitution of an amino acid residue with an amino acid residue having a similar side chain. For example, the substitution between amino acid residues having a basic side chain such as lysine, arginine, or histidine is considered to be a conservative substitution. The following substitutions between other amino acid residues are also considered to be a conservative substitution: the substitution between amino acid residues having an acidic side chain such as aspartic acid or glutamic acid; the substitution between amino acid residues having an uncharged polar side chain such as glycine, asparagine, glutamine, serine, threonine, tyrosine, or cysteine; the substitution between amino acid residues having a nonpolar side chain such as alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine, or tryptophan; the substitution between amino acid residues having a beta-branched side chain such as threonine, valine, or isoleucine; and the substitution between amino acid residues having an aromatic side chain such as tyrosine, phenylalanine, tryptophan, or histidine.

In the present specification, "CDR" is an abbreviation for complementarity determining region. CDR is a region in the variable regions of immunoglobulins and is deeply involved in the specific binding of an antibody to its antigen. The phrase "light-chain CDR" refers to a CDR present in the light-chain variable regions of immunoglobulins, and the phrase "heavy-chain CDR" refers to a CDR present in the heavy-chain variable regions of immunoglobulins.

In the present specification, the phrase "variable region" refers to a region containing CDR1 to CDR3 (simply "CDRs <NUM>-<NUM>" below). The order in which these CDRs <NUM>-<NUM> are arranged is not limited; however, the variable region preferably refers to a region in which CDR1, CDR2, and CDR3 are arranged in this order in the direction from the N-terminus toward the C-terminus or in the reverse order either consecutively or via other amino acid sequences referred to as "framework regions" (FRs), which are described later. The phrase "heavy-chain variable region" refers to a region in which heavy-chain CDRs <NUM>-<NUM> are arranged, and the phrase "light-chain variable region" refers to a region in which light-chain CDRs <NUM>-<NUM> are arranged.

The regions other than CDRs <NUM>-<NUM> of each variable region are referred to as "framework regions" (FRs), as mentioned above. In particular, the region between the N-terminus and CDR1 of a variable region is defined as FR1, the region between CDR1 and CDR2 as FR2, the region between CDR2 and CDR3 as FR3, and the region between CDR3 and the C-terminus of a variable region as FR4.

In an embodiment, the present invention relates to a chimeric antigen receptor comprising a GD2-binding domain comprising a heavy-chain variable region containing a heavy-chain CDR1 containing the amino acid sequence represented by SEQ ID NO: <NUM>, a heavy-chain CDR2 containing the amino acid sequence represented by SEQ ID NO: <NUM>, and a heavy-chain CDR3 containing the amino acid sequence represented by SEQ ID NO: <NUM>; and a light-chain variable region containing a light-chain CDR1 containing the amino acid sequence represented by SEQ ID NO: <NUM>, a light-chain CDR2 containing the amino acid sequence represented by SEQ ID NO: <NUM>, and a light-chain CDR3 containing the amino acid sequence represented by SEQ ID NO: <NUM> (in the present specification, "the GD2-binding molecule of the present invention"). The chimeric antigen receptor comprising a GD2-binding domain of the present invention is described below.

The chimeric antigen receptor comprising a GD2-binding domain of the present invention can be any chimeric antigen receptor comprising a GD2-binding domain as long as the chimeric antigen receptor comprising a GD2-binding domain contains a heavy-chain variable region containing a heavy-chain CDR1 containing the amino acid sequence represented by SEQ ID NO: <NUM>, a heavy-chain CDR2 containing the amino acid sequence represented by SEQ ID NO: <NUM>, and a heavy-chain CDR3 containing the amino acid sequence represented by SEQ ID NO: <NUM>, and a light-chain variable region containing a light-chain CDR1 containing the amino acid sequence represented by SEQ ID NO: <NUM>, a light-chain CDR2 containing the amino acid sequence represented by SEQ ID NO: <NUM>, and a light-chain CDR3 containing the amino acid sequence represented by SEQ ID NO: <NUM>, and as long as the GD2-binding molecule is capable of binding to GD2.

The chimeric antigen receptor comprising a GD2-binding domain of the present invention may be a molecule formed of a single type of polypeptide or a molecule formed of a complex of two or more types of polypeptides. The chimeric antigen receptor comprising a GD2-binding domain of the present invention may also be a molecule formed of a polypeptide or of a complex of polypeptides, or a molecule formed of a polypeptide or complex of polypeptides to which another substance (e.g., a fluorescent substance, a radioactive substance, or an inorganic particle) is linked.

The binding capability to GD2 can be measured in accordance with a known method, for example, by ELISA (specifically, for example, by the method of Test Example <NUM>). The binding capability of the GD2-binding molecule of the present invention to GD2 is, for example, at least <NUM>%, at least <NUM>%, at least <NUM>%, at least <NUM>%, at least <NUM>%, at least <NUM>%, or at least <NUM>% of the binding capability of <NUM>-<NUM> antibody to GD2 in the Examples described later, which are taken as <NUM>%.

The GD2-binding molecule of the present invention preferably contains both the heavy-chain variable region and the light-chain variable region.

The heavy-chain variable region is preferably a heavy-chain variable region containing the amino acid sequence represented by SEQ ID NO: <NUM>, or an amino acid sequence having at least <NUM>% (preferably at least <NUM>%, preferably at least <NUM>%, preferably at least <NUM>%) identity with the amino acid sequence represented by SEQ ID NO: <NUM>. The light-chain variable region is preferably a light-chain variable region containing the amino acid sequence represented by SEQ ID NO: <NUM>, or an amino acid sequence having at least <NUM>% (preferably at least <NUM>%, preferably at least <NUM>%, preferably at least <NUM>%) identity with the amino acid sequence represented by SEQ ID NO: <NUM>. If the amino acid sequence of SEQ ID NO: <NUM> or <NUM> is mutated, the mutation is preferably a substitution of an amino acid, and more preferably a conservative substitution of an amino acid.

The chimeric antigen receptor comprising a GD2-binding domain of the present invention can specifically recognize ganglioside GD2. From this viewpoint, the binding capability of the GD2-binding molecule of the present invention to other antigens, which are at least one member selected from the group consisting of ganglioside GD1a, ganglioside GD1b, ganglioside GD3, ganglioside GM1, ganglioside GM3, ganglioside GT1b, and lactosylceramide (preferably, two members or more, three members or more, four members or more, five members or more, six members or more, or seven members (all)), is preferably <NUM>/<NUM> or less (preferably, <NUM>/<NUM> or less, <NUM>/<NUM> or less, <NUM>/<NUM> or less, <NUM>/<NUM> or less, <NUM>/<NUM> or less, <NUM>/<NUM> or less, or <NUM>/<NUM> or less) of the binding capability of the GD2-binding molecule of the present invention to ganglioside GD2.

The chimeric antigen receptor comprising a GD2-binding domain of the present invention may be chemically modified. The polypeptide that constitutes the GD2-binding molecule of the present invention may have a carboxyl group (-COOH), carboxylate (-COO-), amide (-CONH<NUM>), or ester (-COOR) at the C-terminus. "R" in the ester is, for example, a C<NUM>-<NUM> alkyl group such as methyl, ethyl, n-propyl, isopropyl, or n-butyl; a C<NUM>-<NUM> cycloalkyl group such as cyclopentyl or cyclohexyl; a C<NUM>-<NUM> aryl group such as phenyl or α-naphthyl; a phenyl-C<NUM>-<NUM> alkyl group such as benzyl or phenethyl; a C<NUM>-<NUM> aralkyl group such as an α-naphthyl-C<NUM>-<NUM> alkyl group such as α-naphthyl methyl; or a pivaloyloxymethyl group. The polypeptide that constitutes the GD2-binding molecule of the present invention may have an amidated or esterified carboxyl group (or carboxylate), which is not the carboxyl group at the C-terminus. The ester in this case may be, for example, the esters of the C-terminus described above. The polypeptide that constitutes the GD2-binding molecule of the present invention further includes polypeptides having the amino group of the N-terminal amino acid residue protected by a protective group (e.g., a C<NUM>-<NUM> acyl group including a C<NUM>-<NUM> alkanoyl such as a formyl group and an acetyl group), polypeptides having the N-terminal glutamine residue pyroglutamated that can be formed due to cleavage in vivo; and polypeptides having a substituent (e.g., -OH, -SH, an amino group, an imidazole group, an indole group, and a guanidino group) on a side change of an amino acid in the molecule protected by an appropriate protective group (e.g., a C<NUM>-<NUM> acyl group including a C<NUM>-<NUM> alkanoyl group such as a formyl group and an acetyl group).

The chimeric antigen receptor comprising a GD2-binding domain of the present invention may have a protein or peptide (e.g., a known protein tag or signal sequence) added. Examples of protein tags include biotin, a His tag, a FLAG tag, a Halo tag, a MBP tag, a HA tag, a Myc tag, a V5 tag, a PA tag, and a fluorescent protein tag.

The chimeric antigen receptor comprising a GD2-binding domain of the present invention may be a pharmaceutically acceptable salt formed with an acid or base. The salt can be any pharmaceutically acceptable salt, and can be either an acid salt or a basic salt. Examples of acid salts include inorganic acid salts, such as hydrochloride, hydrobromide, sulfate, nitrate, and phosphate; organic acid salts, such as acetate, propionate, tartarate, fumarate, maleate, malate, citrate, methanesulfonate, and para-toluenesulfonate; and amino acid salts, such as aspartate, and glutamate. Examples of basic salts include alkali metal salts such as sodium salts and potassium salts; and alkaline-earth metal salts, such as calcium salts and magnesium salts.

The chimeric antigen receptor comprising a GD2-binding domain of the present invention may be in the form of a solvate. The solvent can be any pharmaceutically acceptable solvent, and may be, for example, water, ethanol, glycerol, or acetic acid.

According to embodiments that are not part of the invention, the GD2-binding molecule is an antibody (in the present specification, the GD2-binding molecule being an antibody may be referred to as "the antibody").

The antibody can be of any molecular weight. The lower limit is, for example, <NUM>,<NUM>, preferably <NUM>,<NUM>, preferably <NUM>,<NUM>, and more preferably <NUM>,<NUM>. The upper limit is, for example, <NUM>,<NUM>,<NUM>, preferably <NUM>,<NUM>, and more preferably <NUM>,<NUM>.

The antibody may be of any structure. The antibody may contain constant regions, or no constant region. If the antibody contains constant regions, the antibody may contain all of the constant regions of the heavy chain (CH1, CH2, and CH3) and the constant regions of the light chain (CL), or any one or a combination of two or more constant regions of these constant regions.

Specific examples of the structure of the antibody include immunoglobulins, Fab, F(ab')<NUM>, minibody, scFv-Fc, Fv, scFv, diabody, triabody, and tetrabody. Of these, an immunoglobulin is preferable from the standpoint of the effect.

An immunoglobulin has a structure formed of a combination of two structures each of which is composed of a single heavy chain that contains a heavy-chain variable region and a heavy-chain constant region and a single light chain that contains a light-chain variable region and a light-chain constant region.

"Fab" contains a fragment of a heavy chain containing the heavy-chain variable region and CH1 in the heavy-chain constant region and a light chain containing the light-chain variable region and the light-chain constant region (CL), with the heavy-chain variable region and the light-chain variable region being aggregated by non-covalent intermolecular interaction described above, or bound to each other through a disulfide bond. In Fab, CH1 and CL may be linked through a disulfide bond between the thiol groups of the cysteine residues present in CH1 and CL.

"F(ab')<NUM>" contains two pairs of Fabs, with CH1 of one Fab linked with CH1 of the other Fab through a disulfide bond between the thiol groups of their cysteine residues.

"Minibody" refers to the structure in which two fragments each containing CH3 bound to a heavy-chain variable region constituting scFV, described below, are aggregated between CH3 and CH3 by non-covalent intermolecular interaction.

"scFv-Fc" refers to the structure in which two antibody fragments each containing scFv, CH2, and CH3 are aggregated between CH3 and CH3 by non-covalent intermolecular interaction, as with the minibody, and the fragments are linked through a disulfide bond between thiol groups of the cysteine residues contained in each CH3.

"Fv" is considered to be the smallest structural unit of an antibody with the heavy-chain variable region and the light-chain variable region being aggregated by non-covalent intermolecular interaction. In Fv, the thiol group of the cysteine residue present in the heavy-chain variable region may be linked to the thiol group of the cysteine residue present in the light-chain variable region through a disulfide bond.

"scFv" has the structure in which the C-terminus of the heavy-chain variable region and the N-terminus of the light-chain variable region are bound through a linker, or the N-terminus of the heavy-chain variable region and the C-terminus of the light-chain variable region are bound through a linker, and is also referred to as a "single-chain antibody.

The "diabody," "triabody," and "tetrabody" respectively refer to a dimer, a trimer, and a tetramer formed by scFv described above and are each aggregated and structurally stabilized, for example, by non-covalent intermolecular interaction of the variable regions, as with Fv.

If the antibody is an immunoglobulin, its class is not particularly limited. The classes include, for example, IgA, IgD, IgE, IgG, and IgM, as well as subclasses of these classes. The class of the antibody is, for example, IgG or IgM, preferably IgG, and more preferably IgG1.

The origin of the antibody is not particularly limited. The antibody may be, for example, a human-derived antibody, a mouse-derived antibody, a rat-derived antibody, a rabbit-derived antibody, a monkey-derived antibody, or a chimpanzee-derived antibody. The antibody may be a chimeric antibody (e.g., an antibody formed by replacing the amino acid sequence of the constant region of an antibody derived from a non-human organism (e.g., a mouse) with the amino acid sequence of the constant region of a human-derived antibody), a humanized antibody, or a fully humanized antibody.

The antibody can be produced, for example, by a method including culturing a host transformed with a polynucleotide encoding the antibody, and collecting the fraction containing the antibody.

The polynucleotide encoding the antibody can be any polynucleotide that expressibly contains the sequence of the antibody, and may contain other sequences in addition to the coding sequence of the antibody. Other sequences include a secretory-signal-peptide-coding sequence, a promoter sequence, an enhancer sequence, a repressor sequence, an insulator sequence, an origin of replication, and a drug-resistant-gene-coding sequence that are located adjacent to the coding sequence of the antibody. The polynucleotide encoding the antibody may also be a linear polynucleotide or a cyclic polynucleotide (e.g., a vector).

Specific examples of polynucleotides include (I) polynucleotides containing a base sequence encoding at least one member selected from the group consisting of the heavy chain, the heavy-chain variable region, the heavy-chain CDR1, the heavy-chain CDR2, and the heavy-chain CDR3 of the antibody, (II) polynucleotides containing a base sequence encoding at least one member selected from the group consisting of the light chain, the light-chain variable region, the light-chain CDR1, the light-chain CDR2, and the light-chain CDR3 of the antibody, (III) polynucleotides containing a base sequence encoding at least one member selected from the group consisting of the heavy chain, the heavy-chain variable region, the heavy-chain CDR1, the heavy-chain CDR2, and the heavy-chain CDR3 of the antibody, and polynucleotides containing a base sequence encoding at least one member selected from the group consisting of the light chain, the light-chain variable region, the light-chain CDR1, the light-chain CDR2, and the light-chain CDR3 of the antibody.

The host can be any organism, and is, for example, insect cells, eukaryotic cells, or mammal cells. Of these, mammal cells such as HEK cells, CHO cells, NS0 cells, SP2/O cells, or P3U1 cells are preferable from the standpoint of more efficiently expressing the antibody. The methods for transformation, culture, and collection are not particularly limited, and any method known in the field of antibody production can be used. After being collected, the antibody may optionally be purified. Purification can be performed by a method known in the field of antibody production, such as chromatography or dialysis.

In a preferable embodiment, the chimeric antigen receptor comprising a GD2-binding domain the present invention is a chimeric antigen receptor. (In the present specification, the chimeric antigen receptor comprising a GD2-binding domain of the present invention may be referred to as "the chimeric antigen receptor of the present invention.

The chimeric antigen receptor (CAR) is typically a chimeric protein that has its single-chain antibody (scFv) composed of a light chain (VL) bound in tandem to a heavy chain (VH) of the variable region of a monoclonal antibody at a position closer to the N-terminus as a domain responsible for its binding capability to an antigen and its T-cell receptor (TCR) ζ chain at a position closer to the C-terminus. T cells expressing CAR are referred to as "CAR-T cells.

The domain responsible for the binding capability to an antigen (GD2) (GD2-binding domain) in the chimeric antigen receptor of the present invention is not particularly limited as long as the domain contains a heavy-chain variable region containing a heavy-chain CDR1 containing the amino acid sequence represented by SEQ ID NO: <NUM>, a heavy-chain CDR2 containing the amino acid sequence represented by SEQ ID NO: <NUM>, and a heavy-chain CDR3 containing the amino acid sequence represented by SEQ ID NO: <NUM>, and a light-chain variable region containing a light-chain CDR1 containing the amino acid sequence represented by SEQ ID NO: <NUM>, a light-chain CDR2 containing the amino acid sequence represented by SEQ ID NO: <NUM>, and a light-chain CDR3 containing the amino acid sequence represented by SEQ ID NO: <NUM>.

The GD2-binding domain preferably has the structure of scFv. The linker that links the heavy-chain variable region with the light-chain variable region can be any linker that maintains functionality of the chimeric antigen receptor. The linker is preferably a GS linker (typically, a linker having a repeated sequence containing GGGGS (SEQ ID NO: <NUM>) as a structural unit). The number of amino acid residues of the linker is, for example, <NUM> to <NUM>, preferably <NUM> to <NUM>, and more preferably <NUM>.

The chimeric antigen receptor of the present invention typically contains a core domain containing a scFv domain having a heavy-chain variable region and a light-chain variable region, a transmembrane domain, and the intracellular domain of TCR. In the core domain, the scFv domain, the transmembrane domain, and the intracellular domain of TCR are arranged in this order from the N-terminus directly or via other domains.

The transmembrane domain can be of any type that does not interfere with the functionality of the chimeric antigen receptor. For example, CD28, CD3zeta, CD4, or CD8alpha, which are expressed in cells such as T cells, can be used. These transmembrane domains may be mutated as long as the functionality of the chimeric antigen receptor is not interfered with.

The intracellular domain of TCR can be, for example, an intracellular domain derived from CD3, which is also called a "TCRζ chain. " CD3 may be mutated as long as the functionality of the chimeric antigen receptor is not interfered with. Mutation of CD3 is preferably made such that CD3 contains ITAM (immunoreceptor tyrosine-based activation motif).

The chimeric antigen receptor of the present invention preferably has a spacer sequence between the scFv domain and the transmembrane domain. The spacer sequence can be of any length and can be formed of any amino acid residues as long as the functionality of the chimeric antigen receptor is not interfered with. For example, the spacer sequence can be designed so as to have about <NUM> to <NUM> amino acid residues. The spacer sequence for use is preferably the sequence of the constant region of the light chain.

The core domain in the chimeric antigen receptor of the present invention preferably further contains the intracellular domain of a co-stimulator. The intracellular domain of a co-stimulator can be of any intracellular domain derived from a co-stimulator of cells such as T cells. For example, at least one member selected from the group consisting of OX40, <NUM>-1BB, GITR, CD27, CD278, CD28 and the like can be suitably selected and used. The intracellular domain of these co-stimulators may be mutated as long as the functionality of the chimeric antigen receptor is not interfered with. The position of the intracellular domain of a co-stimulator is not particularly limited as long as the intracellular domain is at a position closer to the C-terminus of the transmembrane domain; the intracellular domain may be at a position closer to the N-terminus or the C-terminus of the intracellular domain of TCR.

The chimeric antigen receptor of the present invention preferably contains a ligand domain such as a GITRL domain, a <NUM>-1BBL domain, or an ICOSL domain at a position closer to the C-terminus of the core domain via a self-cleaving peptide domain. This can increase the expression efficiency of the chimeric antigen receptor or the cytotoxic activity of CAR-T cells containing the chimeric antigen receptor.

In the present specification, the phrase "self-cleaving peptide" refers to a peptide sequence with cleavage activity occurring between two amino acid residues in the peptide sequence. Examples of self-cleaving peptides include 2A peptides and 2A-like peptides. For example, in 2A peptides or 2A-like peptides, cleavage occurs between the glycine residue and the proline residue of these peptides. This occurs because of the "ribosomal skipping mechanism," in which a normal peptide linkage between the glycine residue and the proline residue does not form during translation, and this does not affect the translation downstream. The ribosomal skipping mechanism is known in the art and is used in the expression of multiple proteins encoded by a single molecular messenger RNA (mRNA). The self-cleaving peptide for use in the present invention can be obtained from 2A peptides of viruses or 2A-like peptides that have equivalent functionality. For example, the self-cleaving peptide can be selected from the group consisting of 2A peptides derived from foot-and-mouth disease virus (FMDV) (F2A), 2A peptides derived from equine rhinitis A virus (ERAV) (E2A), 2A peptides derived from porcine teschovirus (PTV-<NUM>) (P2A), and 2A peptides derived from Thosea asigna virus (TaV) (T2A). The self-cleaving peptide domain may be mutated as long as the activity of the self-cleaving peptide domain is not greatly impaired.

The GITRL domain is not particularly limited. The GITRL domain is, for example, preferably a domain having the amino acid sequence represented by SEQ ID NO: <NUM>, or an amino acid sequence having at least <NUM>% identity (preferably at least <NUM>%, preferably at least <NUM>%, and preferably at least <NUM>%) with the amino acid sequence represented by SEQ ID NO: <NUM>. If the GITRL domain is an amino acid sequence having a mutation in the amino acid sequence represented by SEQ ID NO: <NUM>, the mutation is preferably a substitution of an amino acid, and more preferably a conservative substitution of an amino acid.

The techniques for producing a chimeric antigen receptor and a CAR-T cell that expresses the chimeric antigen receptor are known. Chimeric antigen receptors and CAR-T cells can be produced in accordance with a known method or an equivalent method.

In an embodiment, the present invention relates to a polynucleotide encoding the chimeric antigen receptor comprising a GD2-binding domain of the present invention (which may be referred to as "the polynucleotide of the present invention" in the present specification). The polynucleotide of the present invention is described below.

The polynucleotide of the present invention may contain other sequences in addition to the coding sequence of the chimeric antigen receptor comprising a GD2-binding domain of the present invention. Preferably, the polynucleotide of the present invention expressibly contains the sequence of the chimeric antigen receptor comprising a GD2-binding domain of the present invention. Other sequences include promoter sequences, enhancer sequences, repressor sequences, insulator sequences, origins of replication, reporter protein (e.g., fluorescent proteins) coding sequences, and drug-resistant-gene-coding sequences. The polynucleotide of the present invention may be a linear polynucleotide or a cyclic polynucleotide (e.g., a vector). The vector can be a plasmid vector or a virus vector (e.g., an adenovirus or retrovirus). The vector can also be, for example, a vector for cloning or for expression. The vector for expression includes vectors for prokaryotic cells, such as Escherichia coli, or actinomycetes, and vectors for eukaryotic cells, such as yeast cells, insect cells, or mammal cells.

The polynucleotide of the present invention includes not only DNA and RNA but also known chemically modified DNA or RNA as described below. To prevent the degradation by hydrolases such as nucleases, the phosphate residue (phosphate) of each nucleotide can be substituted with, for example, a chemically modified phosphate residue such as phosphorothioate (PS), methylphosphonate, or phosphorodithionate. The hydroxyl group at position <NUM> of the ribose of each ribonucleotide may also be substituted with -OR (R represents, for example, CH3(<NUM>'-O-Me), CH<NUM>CH<NUM>OCH<NUM> (<NUM>'-O-MOE), CH<NUM>CH<NUM>NHC(NH)NH<NUM>, CH<NUM>CONHCH<NUM>, or CH<NUM>CH<NUM>CN). Additionally, the base moiety (pyrimidine, purine) may be chemically modified, by, for example, introduction of a methyl group or a cationic functional group into positon <NUM> of the pyrimidine base, or substitution of the carbonyl group at position <NUM> with thiocarbonyl. Additionally, the polynucleotide of the present invention also includes, but is not limited to, those formed by modifying the phosphate moiety or the hydroxyl portion, for example, by biotin, an amino group, a lower alkyl amine group, or an acetyl group. The term "polynucleotide" includes not only natural nucleic acids but also BNA (bridged nucleic acid), LNA (locked nucleic acid), and PNA (peptide nucleic acid).

In an embodiment, the present invention relates to a cell comprising the polynucleotide of the present invention (which may be referred to as "the cell of the present invention" in the present specification). The cell of the present invention is described below.

The cells from which the cell of the present invention is derived are not particularly limited.

When the cell of the present invention comprises a polynucleotide encoding the chimeric antigen receptor of the present invention, the cell is preferably a T cell. The T cell is preferably a cell expressing the chimeric antigen receptor of the present invention. In a more specific embodiment of the T cell of the present invention, the chimeric antigen receptor of the present invention is expressed on the cell membrane, and preferably expressed in such a state that the chimeric antigen receptor comprising a GD2-binding domain is exposed outside the cell membrane.

A T cell or the like expressing the chimeric antigen receptor recognizes GD2 in the GD2-binding domain, and then intracellularly transfers a recognition signal to activate a signal that induces cytotoxic activity. In conjunction with this, the cell mounts attacks against other cells or tissues expressing GD2, or exerts cytotoxic activity.

When a cell exhibiting such a function is a CTL, this cell is called a "chimeric antigen receptor T-cell" ("CAR-T cell"). Cells that have potential to exhibit cytotoxic activity, such as NK cells, can also exert cytotoxic activity when the GD2-binding domain binds to GD2, as with the chimeric antigen receptor T-cell. Thus, a host cell comprising the polynucleotide encoding the chimeric antigen receptor (in particular, a host cell having cytotoxic activity) is useful as an active ingredient of pharmaceutical compositions.

Such CAR-T cells or the like are useful for treatment or prevention of cancer or the like because they specifically recognize cancer tissue (tumor tissue). The type of cancer is not particularly limited, and includes solid cancer and blood cancer. Examples of solid cancer include lung cancer, colorectal cancer, ovarian cancer, breast cancer, brain tumor, stomach cancer, liver cancer, tongue cancer, thyroid cancer, kidney cancer, prostate cancer, uterine cancer, osteosarcoma, chondrosarcoma, rhabdomyosarcoma, melanoma, neuroblastoma, bladder cancer, and the like.

The cell of the present invention can be obtained by introducing the polynucleotide of the present invention into cells. If necessary, the cell containing the polynucleotide of the present invention may be concentrated, or may be concentrated using a specific marker (CD antigen, such as CD8) as an indicator.

In an embodiment, the present invention relates to a pharmaceutical composition comprising the chimeric antigen receptor T-cell or chimeric antigen receptor NK-cell containing the polynucleotide encoding the chimeric antigen receptor of the present invention, (which may be referred to as "the pharmaceutical composition of the present invention" in the present specification). The pharmaceutical composition of the present invention is described below.

The content of the cell in the pharmaceutical composition can be appropriately set in consideration of the type of target disease (e.g., solid cancer), desired therapeutic effects, administration method, treatment period, patient's age, patient's body weight, etc. The content of the cell in the pharmaceutical composition may be, for example, about <NUM> cell/mL to <NUM><NUM> cells/mL.

The administration form of the pharmaceutical composition is not particularly limited as long as the desired effects are obtained. The pharmaceutical composition can be administered to mammals, including humans, by any of the following administration routes: oral administration and parenteral administration (e.g., intravenous injection, intramuscular injection, subcutaneous administration, rectal administration, dermal administration, and local administration). Since the active ingredient is a cell, the administration form is preferably parenteral administration, and more preferably intravenous injection. The dosage forms for oral administration and parenteral administration, and their production methods are well known to a person skilled in the art. The pharmaceutical composition can be produced according to a usual method by, for example, mixing the cell of the present invention with a pharmaceutically acceptable carrier etc..

Examples of dosage forms for parenteral administration include injection preparations (e.g., intravenous drip infusion, intravenous injection, intramuscular injection, subcutaneous injection, and endodermic injection), external preparations (e.g., ointments, cataplasms, and lotions), suppositories, inhalants, eye drops, ophthalmic ointments, nasal drops, ear drops, liposome agents, and the like. For example, an injection preparation can be prepared by dissolving or suspending cells in distilled water for injection, and optionally adding a solubilizer, a buffer, a pH adjuster, an isotonizing agent, a soothing agent, a preservative, a stabilizer, etc. The pharmaceutical composition can also be used as a freeze-dried preparation prepared before use.

The pharmaceutical composition may further comprise other drugs effective for the treatment or prevention of diseases. The pharmaceutical composition can also contain components such as sterilants, antiphlogistics, cell activators, vitamins, and amino acids, if necessary.

As the carrier used for formulating the pharmaceutical composition, excipients, binders, disintegrators, lubricants, coloring agents, and flavoring agents that are generally used in this technical field can be used; and stabilizers, emulsifiers, absorption enhancers, surfactants, pH adjusters, antiseptics, antioxidants, extenders, moisturizers, surface activators, dispersants, buffers, preservatives, solubilizers, soothing agents, and the like can also optionally be used.

The type of disease treated or prevented using the pharmaceutical composition is not particularly limited as long as the treatment or prevention can be achieved. Examples of specific target diseases include tumors. Preferable examples of tumors include GD2-positive tumors. The type of tumor is not particularly limited, and includes solid cancer and blood cancer. Examples of solid cancer include lung cancer (in particular, small-cell lung cancer), colorectal cancer, ovarian cancer, breast cancer, brain tumor, stomach cancer, liver cancer, tongue cancer, thyroid cancer, kidney cancer, prostate cancer, uterine cancer, osteosarcoma, chondrosarcoma, rhabdomyosarcoma, melanoma, neuroblastoma, bladder cancer, and the like.

The administration target (test subject) of the pharmaceutical composition is, for example, an animal having a disease described above or an animal with a potential to develop such a disease. A "potential to develop such a disease" can be determined by a known diagnostic method. The animal is, for example, a mammal, and preferably a human.

The dose of the pharmaceutical composition can be determined by a clinical physician, taking into consideration various factors, such as administration route, the type of disease, the degree of symptoms, patient's age, sex, and body weight, severity of disease, pharmacological findings such as pharmacokinetics and toxicological characteristics, use or non-use of drug delivery system, and whether the composition is administered as part of a combinational drug with other medicinal agents. When the active ingredient is the cell, the dose can be about <NUM><NUM> cells/kg (body weight) to <NUM><NUM> cells/kg (body weight). The administration schedule of the pharmaceutical composition can also be determined taking into consideration the same factors as those for the dose. For example, the composition can be administered once a day to once a month in the daily dose described above.

The present invention is described in detail below with reference to Examples. However, the present invention is not limited to these Examples.

Unless otherwise specified, the following materials and methods were used in the Test Examples.

Carney and AS were obtained from Dr. IMR32, CEM, Kokl-<NUM>, and MOLT4 were obtained from Dr. YTN17 was provided by Dr. Yodoi, and subline N1 of SK-MEL-<NUM> cells was provided by Dr. NCI-<NUM>, ACC-LC-<NUM>, ACC-LC-<NUM>, and ACC-LC-<NUM> were provided by Dr. Takashi Takahashi. C-<NUM> cells D-<NUM> were prepared by introducing GD3 synthase into ACC-LC-<NUM>. GD2-expressing cells S1 and S6 were prepared by introducing, into subline N1 (GD3, not expressing GD3) of SK-MEL-<NUM> cells, pCDNA3.1neo into which GD3 synthase and GM2/GD2 synthase cDNAs were incorporated. V4 and V9 are those into which empty vector pCDNA3.1neo was introduced.

A rabbit anti-human kappa antibody (<NUM>) was purchased from MBL. An Alexa <NUM>-labeled anti-rabbit IgG antibody (A11034) was purchased from Invitrogen. A PE-labeled anti-GITRL antibody (FAB6941P) was purchased from BioLegend. A PE-labeled anti-human <NUM>-1BB antibody (<NUM>) was purchased from BioLegend. A PE-labeled anti-human ICOSL antibody (<NUM>) was purchased from BioLegend. An APC-labeled anti-human CD4 antibody (clone RPA-T4) was purchased from Invitrogen. A PE-labeled anti-human CD4 antibody (<NUM>) was purchased from BD. An APC/Cy7-labeled anti-human CD8 antibody (clone HT8a) was purchased from BioLegend. A FITC-labeled anti-human Vd2 antibody (clone B6, <NUM>) was purchased from BioLegend. A V450-labeled anti-human IFNg antibody (clone <NUM>, <NUM>-<NUM>-<NUM>) was purchased from BD Pharmingen. A PE/Cy7-labeled anti-human TNFa antibody (clone Mab11, <NUM>-<NUM>-<NUM>) was purchased from eBioscience. An APC-labeled anti-human CD107a antibody (<NUM>) was purchased from BD Pharmingen.

CD1928 and CD1928z GITRL prepared by Eurofins were subjected to enzymatic treatment with restriction enzymes NotI and XhoI, and recombined to pMS3 to prepare plasmid vectors. Luciferase NGFR expression vectors were prepared by treating these two prepared by Eurofins' custom synthesis with NotI and ClaI, and ClaI and XhoI, respectively, and recombining them into pMS3. These were introduced into Plat-A using FuGENE to prepare retroviruses. The method was performed according to the manufacturer's instructions.

After <NUM> micrograms of OKT3 and <NUM> micrograms of RetroNectin were immobilized on a <NUM>-well plate, peripheral blood mononuclear cells adjusted with Ficoll were cultured in GT-T551 supplemented with <NUM>% human plasma and IL-<NUM> at a final concentration of <NUM> u/ml, collected on day <NUM>, infected with retroviruses immobilized at <NUM> for <NUM> hours at <NUM>×g, and cultured.

Gamma/delta cells were made according to the method of Tanaka et al. Gamma/delta cells (obtained by culturing peripheral blood mononuclear cells in YM-AB containing a novel bisphosphonate preparation (PTA), adding <NUM> ng/ml of IL-<NUM> and <NUM> ng/ml of IL-<NUM>, and collecting them on day <NUM>) were infected and cultured in the same medium.

For CAR expression, an anti-kappa antibody was reacted at <NUM> micrograms/ml, followed by washing; Alexa <NUM>-labeled anti-rabbit IgG (Invitrogen) was reacted at <NUM> micrograms/ml, followed by washing; staining with an APC/Cy7-labeled anti-human CD8 antibody (BD) and an APC-labeled anti-human CD4 antibody (BioLegend) was performed; and measurement was performed with a FACSCanto. For GITRL expression, PE-labeled anti-human GITRL (BioLegend) was diluted <NUM>-fold and reacted, and measurement was performed with a FACSCanto. Intracellular staining of GITRL with BD Cytofix/Cytoperm and BD Perm/Wash was performed using a PE-labeled anti-human GITRL antibody (BioLegend). The method was performed according to the manufacturer's instructions.

After CAR-transduced PBMCs and target cells were mixed, the cells were reacted with an APC-labeled anti-human CD107a antibody, and cultured in a CO<NUM> incubator for <NUM> hour. Thereafter, GolgiStop was allowed to act, and culture was performed in a CO<NUM> incubator for <NUM> hours, followed by washing. Staining with an anti-human kappa antibody and an Alexa <NUM>-labeled anti-rabbit IgG antibody was performed, and then staining with an APC/Cy7-labeled anti-CD8 antibody and a PE-labeled anti-human CD4 antibody was performed. After treatment with BD Cytofix/Cytoperm and BD Perm/Wash, staining was performed with V450-labeled anti-human IFNg and PE/Cy7-labeled anti-human TNFa.

<NUM>×<NUM><NUM> target cells AS suspended in <NUM> microliters of RPMI <NUM><NUM>% FCS were placed and allowed to stand in a CO<NUM> incubator for <NUM> hours. Thereafter, <NUM>×<NUM><NUM> effector cells suspended in <NUM> microliters of RPMI <NUM><NUM>% FCS were placed, and the subsequent changes in current were recorded.

The experiment was performed according to the manufacturer's instructions. Specifically, first, <NUM>×<NUM><NUM> target AS cells were suspended in <NUM> microliters of <NUM>% FCS/PRMI <NUM>, and <NUM> microliter of a BM-HT solution was added thereto, followed by culturing in a CO<NUM> incubator for <NUM> minutes. After washing, <NUM>×<NUM><NUM> cells were prepared, and <NUM>×<NUM><NUM>, <NUM>×<NUM><NUM>, and <NUM>×<NUM><NUM> CAR-T cells were added thereto, and the cells were co-cultured for <NUM> hours and then centrifuged to collect <NUM> microliters of a supernatant. <NUM> microliters of an EU solution was added thereto, followed by mixing. Thereafter, luminescence was measured with a TriStar2 SLB942 Multimode Reader (Berthold Technologies).

A Balb/c x C57BL/<NUM> F1 mouse was immunized with three subcutaneous inoculations of IMR32 cells, and the collected spleen cells were fused with NS-<NUM> cells, followed by culturing in RPMI <NUM> medium containing <NUM>% FCS and HAT, thereby obtaining monoclonal antibodies. The obtained antibodies were screened by flow cytometry recognition for IMR32 cells. Subclones of the obtained clone <NUM> were further obtained, and <NUM>-<NUM> was obtained.

The antigen specificity of the <NUM>-<NUM> antibody was analyzed by ELISA. Gangliosides GD1a, GD1b, GD2, GD3, GM1, GM3, and GT1b, and lactosylceramide (<NUM> ng each) were immobilized with methanol. Each serially diluted ascites antibody was reacted, and an HRP-labeled anti-mouse IgG antibody (Southern Biotech) was reacted. Color was developed using OPD, and the absorbance was measured.

<FIG> shows the results. The <NUM>-<NUM> antibody recognized only GD2 and did not recognize any of the other gangliosides.

The antigen specificity of the <NUM>-<NUM> antibody was analyzed by thin-layer chromatography. A mixture of a bovine-derived ganglioside and GM3, and gangliosides derived from cancer cells SK-MEL-<NUM> (Carney2) and AS were subjected to thin-layer chromatography and transferred onto a PVDF membrane with a heat blotter (ATTO TLC Thermal Blotter AC5970, Atto, Tokyo), and the <NUM>-<NUM> antibody was then reacted. Thereafter, HRP-conjugated anti-mouse IgG (whole) (Cell Signaling), which is an HRP-labeled anti-mouse secondary antibody, was reacted, followed by light emission with a Western Lightning™ Plus ECL (PerkinElmer Inc. , Waltham, MA).

<NUM>×<NUM><NUM> cells were treated with the <NUM>-fold diluted antibody in <NUM>% BSA/PBS at room temperature for <NUM> minutes, washed, treated with a FITC-labeled anti-mouse IgG antibody (Cappel), washed with PBS, and measured with a FACS Caliver or Accuri C6.

<FIG> shows the results. The <NUM>-<NUM> antibody recognized GD2+ AS, IMR32, Kohl-<NUM> (SK-MEL-<NUM>), and YTN17, but did not recognize GD2- CEM or MOLT4.

GD2+ melanoma S1 and S6 cells, and GD2- V4 and V9 cells (number of cells: <NUM>×<NUM><NUM>) were seeded on a plate on which collagen was immobilized, and adhesion was observed with an RT-CES when the <NUM>-<NUM> antibody was diluted <NUM>-fold and reacted at <NUM> hours and <NUM> hours (S1-T: addition of antibody to S1).

<FIG> shows the results. The <NUM>-<NUM> antibody inhibited the adhesion of GD2+ S1 and S6 cells, but did not inhibit the adhesion of GD2- V4 or V9 cells.

The amino acid sequence of the <NUM>-<NUM> antibody and the base sequence encoding the antibody were analyzed. The analysis results are shown below. The sequences of the CDRs were deduced by IMGIT.

Four CARs (28z CAR, zG CAR, 28z GITRL CAR, and zG GITRL CAR) were designed using the amino acid sequence of the <NUM>-<NUM> antibody (<FIG> schematically shows the structures). Expression plasmids for these CARs were prepared. Specifically, the expression plasmids were prepared as follows.

For 28z CAR and zG CAR, artificial genes of the following two sequences were created by Eurofins, excised with NotI and XhoI, and inserted into pMS3 to obtain expression plasmids.

For 28z GITRL CAR, an expression plasmid in which the following P2A-GITRL base sequence was incorporated adjacent to the <NUM>' side of the base sequence of SEQ ID NO: <NUM> of the 28z CAR expression plasmid was prepared using the artificial gene and PCR. P2A-GITRL base sequence:
<IMG>
<IMG>.

The amino acid sequence of P2A-GITRL is as follows: GSGATNFSLLKQAGDVEENPGP (P2A amino acid sequence: SEQ ID NO: <NUM>)-MTLHPSPITCEFLFSTALISPKMCLSHLENMPLSHSRTQGAQRSSWKLWLFCSIVMLLFLCSFSW LIFIFLQLETAKEPCMAKFGPLPSKWQMASSEPPCVNKVSDWKLEILQNGLYLIYGQVAPNANYN DVAPFEVRLYKNKDMIQTLTNKSKIQNVGGTYELHVGDTIDLIFNSEHQVLKNNTYWGIILLANP QFIS (GITRL amino acid sequence: SEQ ID NO: <NUM>).

For zG GITRL CAR, an expression plasmid in which the P2A-GITRL base sequence was incorporated adjacent to the <NUM>' side of the base sequence of SEQ ID NO: <NUM> of the zG CAR expression plasmid was prepared using the artificial gene and PCR.

Each plasmid DNA constructed as mentioned above was introduced into Plat-A cells to prepare retroviruses. Cultured human PBMCs were infected with the retroviruses to obtain CAR-transduced T cells, and CAR expression was examined by flow cytometry. CAR and ligand expression was confirmed in alpha/beta T cells as shown in <FIG>, and in gamma/delta T cells as shown in <FIG> and <FIG>. These are effector cells. It was confirmed that the expression efficiency and expression intensity (indicated by mean fluorescent intensity; MFI) of the CARs were enhanced by co-expression with GITRL (<FIG>).

CAR-T cells are activated and express IFNg and TNFa when co-cultured with target AS cells. In addition, CD107a is transported to the cell surface. These reactions indicate that multifunctional reactions have occurred. It was confirmed that all kinds of the CAR-T cells produced in this experiment were activated by co-culture with AS cells, and that these reactions occurred (<FIG>).

The cytotoxic action of the effector cells on AS cells was examined according to changes over time by using xCELLigence. The results showed that GD2 CAR had sufficient cytotoxic activity in alpha/beta T cells and gamma/delta T cells (<FIG> and <FIG>). This was also observed in a non-radioactive cytotoxicity test (<FIG>).

After GD2-positive Kelly cells (<NUM> cells) were cultured on an E-plate for <NUM> hours, each kind of the effector cells (alpha/beta) (<NUM> cells) was added and cultured, and the cell index was tracked over time. The cell index reflects the number of Kelly cells on the E-plate. The normalized cell index is a cell index normalized on the assumption that the number of Kelly cells immediately before co-culture with the effector cells was <NUM>. The graph shows the average values (n = <NUM>). Effective cytotoxicity by GD2 28z, GD2 zG, and GITRL-co-expressing GD2 28z CAR-T cells was observed, and no cytotoxicity by PBMCs into which a CAR was not introduced was observed (<FIG>).

After GD2-negative SK-N-SH cells (<NUM> cells) were cultured on an E-plate for <NUM> hours, each kind of the effector cells (alpha/beta) (<NUM> cells) was allowed to act thereon, and the cell index was tracked over time. The cell index reflects the number of SK-N-SH cells on the E-plate. The normalized cell index is a cell index normalized on the assumption that the number of SK-N-SH cells immediately before co-culture with the effector cells was <NUM>. The graph shows the average values (n = <NUM>). No cytotoxicity by GD2 28z, GD2 zG, or GITRL-co-expressing GD2 28z CAR-T cells was observed (<FIG>).

After GD2-positive Hs578T-Luc cells (<NUM> cells) were cultured on an E-plate for <NUM> hours, each kind of the effector cells (alpha/beta) (<NUM> cells) was allowed to act thereon, and the cell index was tracked over time. The cell index reflects the number of Hs578T-Luc cells on the E-plate. The normalized cell index is a cell index normalized on the assumption that the number of Hs578T-Luc cells immediately before co-culture with the effector cells was <NUM>. The graph shows the average values (n = <NUM>). Effective cytotoxicity by GD2 28z, GD2 zG, and GITRL-co-expressing GD2 28z CAR-T cells was observed, and no cytotoxicity by PBMCs into which a CAR was not introduced was observed (<FIG>).

After GD2-negative BT549-Luc cells (<NUM> cells) were cultured on an E-plate for <NUM> hours, each kind of the effector cells (alpha/beta) (<NUM> cells) was allowed to act thereon, and the cell index was tracked over time. The cell index reflects the number of BT549-Luc cells on the E-plate. The normalized cell index is a cell index normalized on the assumption that the number of BT549-Luc cells immediately before co-culture with the effector cells was <NUM>. The graph shows the average values (n = <NUM>). No cytotoxicity by GD2 28z, or GITRL-co-expressing GD2 28z CAR-T cells was observed (<FIG>).

After GD2-positive Kelly cells (<NUM> cells) were cultured on an E-plate for <NUM> hours, each kind of the effector cells (alpha/beta) (<NUM> cells) was allowed to act thereon, and the cell index was tracked over time. One day later, effective cytotoxicity by GD2 28z and GITRL-co-expressing GD2 28z CAR-T cells was observed. The effector cells were collected and successively co-cultured with Kelly cells cultured on an E-plate for <NUM> hours, and changes in the cell index were recorded over time. The cell index reflects the number of Kelly cells on the E-plate. The normalized cell index is a cell index normalized on the assumption that the number of Kelly cells immediately before co-culture with the effector cells was <NUM>. The graph shows the average values (n = <NUM>). In the second successive cytotoxicity test, the GITRL-co-expressing 28z CAR-T cells retained stronger cytotoxic activity than 28z CAR (<FIG>).

D8 cells are a GD2-positive cell line established by introduction of GD3 synthase and GD2 synthase genes into GD2-negative small-cell lung cancer SK-LC-<NUM>, and G418 selection. After GD2-positive D8 cells (<NUM> cells) were cultured on an E-plate for <NUM> hours, each kind of the effector cells (alpha/beta) (<NUM> cells) was allowed to act thereon, and the cell index was tracked over time. The cell index reflects the number of D8 cells on the E-plate. The normalized cell index is a cell index normalized on the assumption that the number of D8 cells immediately before co-culture with the effector cells was <NUM>. The graph shows the average values (n = <NUM>). Effective cytotoxicity by GD2 28z, GD2 zG, and GITRL-co-expressing GD2 28z CAR-T cells was observed, and no cytotoxicity by PBMCs into which a CAR was not introduced was observed (<FIG>).

C2 cells are a GD2-negative cell line established by introduction of a pCDNA3.1neo plasmid into GD2-negative small-cell lung cancer SK-LC-<NUM>, and G418 selection. After GD2-negative C2 cells (<NUM> cells) were cultured on an E-plate for <NUM> hours, each kind of the effector cells (alpha/beta) (<NUM> cells) was allowed to act thereon, and the cell index was tracked over time. The cell index reflects the number of C2 cells on the E-plate. The normalized cell index is a cell index normalized on the assumption that the number of C2 cells immediately before co-culture with the effector cells was <NUM>. The graph shows the average values (n = <NUM>). No cytotoxicity by GD2 28z, GD2 zG, GITRL-co-expressing GD2 28z CAR-T cells, or PBMCs into which a CAR was not introduced was observed (<FIG>).

Claim 1:
A chimeric antigen receptor comprising a GD2-binding domain comprising
a heavy-chain variable region containing
a heavy-chain CDR1 containing the amino acid sequence represented by SEQ ID NO: <NUM>,
a heavy-chain CDR2 containing the amino acid sequence represented by SEQ ID NO: <NUM>, and
a heavy-chain CDR3 containing the amino acid sequence represented by SEQ ID NO: <NUM>, and
a light-chain variable region containing
a light-chain CDR1 containing the amino acid sequence represented by SEQ ID NO: <NUM>,
a light-chain CDR2 containing the amino acid sequence represented by SEQ ID NO: <NUM>, and
a light-chain CDR3 containing the amino acid sequence represented by SEQ ID NO: <NUM>.