TW201825524A - Novel anti-PCSK9 antibody - Google Patents

Abstract

The invention provides a monoclonal antibody for a proprotein convertase subtilisin Kexin 9 (PCSK9). The monoclonal antibody can block the binding of PCSK9 to a LDL receptor so that the level of LDL-Cis reduced. The monoclonal antibody provides a very effective agent for treating various CVD diseases.

Description

New anti-PCSK9 antibody

The present invention relates to a novel anti-PCSK9 antibody.

Cardiovascular disease has been the number one killer of human health and life (World Health Organization (WHO), World Health Organization (2011). Various research reports have shown that lowering LDL cholesterol can effectively reduce the risk of cardiovascular disease At present, statins are mainly used to lower cholesterol. However, many patients do not tolerate high doses of statins because of side effects or because statins cannot effectively control blood lipids (Baigent, C. et al., Lancet 2000, 376 (9753) , 1670-1681), so there is a strong need for new treatments in this field. The proprotein-converting enzyme subtilisin Kexin type 9 (PCSK9) was first discovered as a converting enzyme-1 that regulates neuronal apoptosis. It is mainly found in the small intestine and liver Sinosynthesis (Seidah NG et al., Proc Natl Acad Sci USA 2003; 100: 928-33). The predomain is self-lysed by cells to become mature PCSK9, and then secreted by liver cells (McNutt, MC et al. , J. Biol. Chem. 2007, 20 (282), 20799-20803). PCSK9 plays an important role in the regulation of cholesterol metabolism. Researchers in two patients with A functionally enhanced mutant gene of PCSK9 has been found in the French family of chromosomal dominant inherited hypercholesterolemia, which has revealed its role in the regulation of cholesterol metabolism (Abifadel M et al., Nat Genet 2003; 34: 154-6). PCSK9 mainly breaks down in the liver by binding to low-density lipoprotein receptor (LDLR) to regulate cholesterol levels. In the absence of PCSK9, the low-density lipoprotein receptor on liver cells transports low density After the degradation of lipoprotein cholesterol to lysozyme, it will be recycled back to the cell membrane surface. When PCSK9 binds to the low-density lipoprotein receptor, it will hinder the recycling of LDLR and will aggravate its degradation (Verbeek, R., et al , Eur J Pharmacol 2015; Lo Surdo P et al., EMBO Rep 2011; 12: 1300-5). Several methods currently under investigation for inhibiting PCSK9 include preventing the binding of PCSK9 and LDLR by binding of antibodies or peptides. Gene silencing inhibits PCSK9 synthesis, and small molecule drugs inhibit PCSK9's intracellular synthesis (Michel Farnier, Archives of Cardiovascular Disease, 2014, 107, 58-66). Recently approved single strain Body Alirocumab and Evolocumab have shown significant effect in reducing low-density lipoprotein cholesterol and in two clinical studies in three. Available data show that the level of low-density lipoprotein cholesterol can be reduced by 70% whether or not they have been treated with statins (Dias, CS et al., J. Am. Coll. Cardiol. 2012, 60 (19), 1888-1898 Giugliano, RP et al., Lancet, 2012, 380 (9858), 2007-2017; McKenney, JM et al., J. Am. Coll. Cardiol. 2012, 59 (25), 2344-2353).

The application provides novel anti-PCSK9 monoclonal antibodies (especially humanized antibodies), polynucleotides encoding the same, and methods for using the same. In one aspect, the application provides an isolated antibody or antigen-binding fragment thereof comprising a heavy chain CDR sequence selected from the group consisting of SEQ ID NOs: 1, 3, 5, 13, 15, and 17. In certain embodiments, the antibody or antigen-binding fragment thereof comprises a light chain CDR sequence selected from the group consisting of: SEQ ID NOs: 7, 9, 11, 19, 21, 23, and 25. In certain embodiments, the antibody or antigen-binding fragment thereof comprises a heavy chain variable region selected from the group consisting of: a) a heavy chain variable region comprising SEQ ID NO: 1, SEQ ID NO: 3, and / Or SEQ ID NO: 5; and b) a heavy chain variable region comprising SEQ ID NO: 13, SEQ ID NO: 15 and / or SEQ ID NO: 17. In certain embodiments, the antibody or antigen-binding fragment thereof described herein comprises a light chain variable region selected from: a) a light chain variable region comprising SEQ ID NO: 7 SEQ ID NO: 9 and / or SEQ ID NO: 11; b) a light chain variable region comprising SEQ ID NO: 19, SEQ ID NO: 21 and / or SEQ ID NO: 23; and c) a light chain A variable region comprising SEQ ID NO: 25, SEQ ID NO: 21, and / or SEQ ID NO: 23. In certain embodiments, the antibodies or antigen-binding fragments thereof described herein include: a) a heavy chain variable region comprising SEQ ID NO: 1, SEQ ID NO: 3, and / or SEQ ID NO: 5; And a light chain variable region comprising SEQ ID NO: 7, SEQ ID NO: 9 and / or SEQ ID NO: 11; b) a heavy chain variable region comprising SEQ ID NO: 13, SEQ ID NO: 15 And / or SEQ ID NO: 17; and a light chain variable region comprising SEQ ID NO: 19, SEQ ID NO: 21 and / or SEQ ID NO: 23; or c) a heavy chain variable region comprising SEQ ID NO: 13, SEQ ID NO: 15 and / or SEQ ID NO: 17; and a light chain variable region comprising SEQ ID NO: 25, SEQ ID NO: 21 and / or SEQ ID NO: 23. In certain embodiments, the antibody or antigen-binding fragment thereof described herein comprises a heavy chain variable region selected from the group consisting of SEQ ID NO: 36, SEQ ID NO: 40, SEQ ID NO: 44, SEQ ID NO: 48 and its sequence is at least 80% (e.g. at least 85%, 88%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99%) Homologous sequences. In certain embodiments, the antibody or antigen-binding fragment thereof described herein comprises a light chain variable region selected from the group consisting of SEQ ID NO: 27, SEQ ID NO: 31, and having at least 80% (such as at least 85%, 88%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99%) sequence homology. In certain embodiments, the antibodies or antigen-binding fragments thereof described herein include a) a heavy chain variable region including SEQ ID NO: 36; and a light chain variable region including SEQ ID NO: 38; b) a heavy chain variable region including SEQ ID NO: 40; and a light chain variable region including SEQ ID NO: 42; c) a heavy chain variable region including SEQ ID NO: 44; and a light chain A variable region comprising SEQ ID NO: 46; d) a heavy chain variable region comprising SEQ ID NO: 48; and a light chain variable region comprising SEQ ID NO: 50; or c) and a), b), c) or d) have at least 80% (e.g. at least 85%, 88%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% ) The heavy and light chain variable regions of sequence identity. In some embodiments, the antibodies or antigen-binding fragments thereof described herein can be no more than 10 ^-7 M, no more than 10 ^-8 M, no more than 10 ^-9 M, no more than 10 ^-10 M, no more than A KD value of 10 ^-11 M or not more than 10 ^-12 M specifically binds to human PCSK9, and the Kd value is determined by a surface plasmon resonance binding method. In some embodiments, the antibodies or antigen-binding fragments thereof described herein can be no more than 10 ^-7 M, no more than 10 ^-8 M, no more than 10 ^-9 M, no more than 10 ^-10 M, no more than A KD value of 10 ^-11 M or not exceeding 10 ^-12 M specifically binds to human PCSK9, and the Kd value is determined by an ELISA method. In some embodiments, the antibodies or antigen-binding fragments thereof described herein can be no more than 10 ^-7 M, no more than 10 ^-8 M, no more than 10 ^-9 M, no more than 10 ^-10 M, no more than KD values of 10 ^-11 M or no more than 10 ^-12 M specifically bind to monkey PCSK9. In certain embodiments, the antibodies or antigen-binding fragments thereof described herein can be no more than 10 nM, no more than 5 nM, or no more than 3 nM (for example, no more than 30 nM, 20 nM, 15 nM, 9 nM, 8 nM , 7 nM, 6 nM, 4 nM, 2 nM, or 1 nM) block the binding of human PCSK9 to its ligand. In certain embodiments, the antibodies or antigen-binding fragments thereof described herein can be no more than 0.15 nM (e.g., no more than 1.5, 1, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, or 0.05 nM) in combination with human PCSK9. In certain embodiments, the antibodies or antigen-binding fragments thereof described herein can have IC50 values of no more than 140 nM, no more than 92 nM, or no more than 80 nM (e.g., no more than 180 nM, 120 nM, 100 nM, 85 nM, 70 nM, 60 nM, 50 nM, 40 nM, or 30 nM) to restore cellular LDL uptake. In certain embodiments, the antibody or antigen-binding fragment thereof described herein is stable in serum for at least 3 days, at least 4 days, at least 5 days, at least one week, at least 2 weeks, at least one month. In certain embodiments, the antibodies or antigen-binding fragments thereof described herein do not mediate ADCC or CDC or neither. In certain embodiments, the antibodies or antigen-binding fragments thereof described herein are humanized monoclonal antibodies. In certain embodiments, the humanized monoclonal antibody is produced by a host cell. In certain embodiments, the antibodies or antigen-binding fragments thereof described herein can reduce LDL cholesterol levels in animals to 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45% , 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% or more. In certain embodiments, the antibodies or antigen-binding fragments thereof described herein are capable of maintaining HDL cholesterol levels in animals. In certain embodiments, the antibodies or antigen-binding fragments thereof described herein have a serum half-life (e.g., at least 50, at least 60, at least 70, at least 80, at least 90, at least 100, at least 150, at least 180, at least 200, at least 250, at least 300, at least 350, at least 400, at least 450, or at least 500 hours). In one aspect, the application provides an antibody or antigen-binding fragment thereof that competes with the antibody or antigen-binding fragment thereof described in the application for the same epitope. In certain embodiments, the present application provides an antibody or antigen-binding fragment thereof which is a camelized single chain domain antibody, a diabody, scFv, scFv dimer, BsFv, dsFv, ( dsFv) 2, dsFv-dsFv ', Fv fragment, Fab, Fab', F (ab ') 2, ds diabody, nanobody, domain antibody or bivalent domain antibody. In certain embodiments, the present application provides an antibody or antigen-binding fragment thereof further comprising an immunoglobulin constant region. In certain embodiments, the application provides an antibody or antigen-binding fragment thereof further comprising a conjugate. In certain embodiments, the conjugate can be a detectable label, a pharmacokinetic modified portion, or a purified portion. In one aspect, the application also provides an isolated polynucleotide that encodes an antibody or antigen-binding fragment thereof as described herein. In certain embodiments, a polynucleotide provided herein encodes an amino acid sequence of an antibody or antigen-binding fragment thereof as described herein. In certain embodiments, the application provides vectors comprising such polynucleotides. In certain embodiments, the present application provides a method of expressing one or more of the antibodies or antigen-binding fragments described herein by culturing a host under conditions in which an antibody or antigen-binding fragment encoded by a polynucleotide is expressed in a vector. Cell realization. In certain embodiments, the polynucleotides provided herein are operably linked in a vector to a promoter, such as the SV40 promoter. In certain embodiments, the host cell comprising the vector provided herein is a Chinese hamster ovary cell, or a 293 cell. In one aspect, the application provides a method of expressing an antibody or antigen-binding fragment thereof as described herein, comprising culturing the host cell under conditions that express the polynucleotide. In one aspect, the application provides a kit comprising an antibody or antigen-binding fragment thereof described herein. In one aspect, the application provides a method of treating a PCSK9-related disease or condition in an individual, comprising administering to the individual a therapeutically effective amount of an antibody or antigen-binding fragment thereof described herein. In certain embodiments, the individual is identified as having a disorder or condition that is likely to respond to a PCSK9 inhibitor. In certain embodiments, the individual is identified as having an increased level of serum LDL cholesterol (LDL-C), total cholesterol, and / or non-HDL cholesterol or a reduced level of LDL receptor in a biological sample to be tested from the individual. In certain embodiments, the LDL-C and / or total cholesterol level is reduced after the antibody or antigen-binding fragment thereof is administered. In one aspect, the present application also provides a pharmaceutical composition including the antibody or antigen-binding fragment thereof described in the present application and one or more pharmaceutically acceptable carriers. In certain embodiments, the pharmaceutical carrier may be, for example, a diluent, an antioxidant, an adjuvant, an excipient, or a non-toxic auxiliary substance. In one aspect, the application also provides a method of treating a condition in an individual who would benefit from an up-regulated immune response, comprising administering to the individual an effective amount of an antibody or antigen-binding fragment thereof described herein. In certain embodiments, the individual has an up-regulated LDL-C, total cholesterol, and / or non-HDL cholesterol level or a down-regulated LDL receptor level. In one aspect, the use of an antibody or antigen-binding fragment thereof as described herein for the manufacture of a medicament for treating a condition that would benefit from an up-regulated immune response is provided. In certain embodiments, the conditions are cardiovascular disease, inflammatory disease, and infectious disease. In one aspect, the infectious disease is sepsis.

The following description of this application is only to illustrate various embodiments of this application. Therefore, the specific modifications discussed here should not be construed as limiting the scope of the application. Those skilled in the art can easily obtain various equivalents, changes, and modifications without departing from the scope of the present application. It should be understood that such equivalent embodiments are included in the scope of the present invention. All documents cited in this application, including published publications, patents and patent applications, are incorporated by reference in their entirety.definition The term "antibody" in the present invention includes any immunoglobulin, monoclonal antibody, polyclonal antibody, multispecific antibody, or bispecific (bivalent) antibody that can bind to a specific antigen. A natural intact antibody contains two heavy chains and two light chains. Each heavy chain is composed of a variable region and the first, second, and third constant regions; each light chain is composed of a variable region and a constant region. Mammalian heavy chains can be divided into α, δ, ε, γ, and μ, and mammalian light chains can be divided into λ or κ. The antibody is of "Y" type, and the neck of the "Y" type structure is composed of the second and third constant regions of two heavy chains, which are bound by disulfide bonds. Each arm of the "Y" structure includes one of the heavy chain variable region and the first constant region, which is combined with the variable and constant region of a light chain. The variable regions of the light and heavy chains determine antigen binding. The variable region of each chain contains three hypervariable regions, called complementarity determining regions (CDRs) (the CDRs of the light chain (L) include LCDR1, LCDR2, LCDR3, and the CDRs of the heavy chain (H) include HCDR1, HCDR2, HCDR3) . The CDR boundaries of the antibodies and antigen-binding fragments disclosed in the present invention can be named or identified by Kabat, Chothia or Al-Lazikani nomenclature. (Al-Lazikani, B., Chothia, C., Lesk, AM, J. Mol. Biol., 273 (4), 927 (1997); Chothia, C. et al., J Mol Biol. Dec 5; 186 ( 3): 651-63 (1985); Chothia, C. and Lesk, AM, J. Mol. Biol., 196,901 (1987); Chothia, C. et al., Nature. Dec 21-28; 342 (6252): 877-83 (1989); Kabat EA et al., National Institutes of Health, Bethesda, Md. (1991)). Among them, the three CDRs are separated by a side continuous portion called a framework region (FR). The framework region is more highly conserved than the CDR and forms a scaffold to support the hypervariable loop. The constant regions of the heavy and light chains have nothing to do with antigen binding, but have multiple effector functions. Antibodies can be classified into several classes based on the amino acid sequence of the constant region of the heavy chain. Depending on whether they contain α, δ, ε, γ, and μ heavy chains, antibodies can be divided into five main classifications or isomers: IgA, IgD, IgE, IgG, and IgM. Several major antibody classifications can also be divided into subclasses, such as IgG1 (γ1 heavy chain), IgG2 (γ2 heavy chain), IgG3 (γ3 heavy chain), IgG4 (γ4 heavy chain), IgA1 (α1 heavy chain), or IgA2 (α2 heavy chain) and the like. The term "antigen-binding fragment" in this application refers to an antibody fragment formed by an antibody portion containing one or more CDRs or any other antibody fragment that binds an antigen but does not have a complete antibody structure. Examples of antigen-binding fragments include, but are not limited to, such as diabody, Fab, Fab ', F (ab')₂ , Fv fragment, disulfide-stabilized Fv fragment (dsFv), (dsFv)₂ , Bispecific dsFv (dsFv-dsFv '), disulfide stabilized bifunctional antibody (ds diabody), single chain antibody molecule (scFv), scFv dimer (bivalent bifunctional antibody), bivalent single chain Antibodies (BsFv), multispecific antibodies, camelized single domain antibodies, nanobodies, domain antibodies, and bivalent domain antibodies. The antigen-binding fragment can bind the same antigen as the parent antibody. In some embodiments, the antigen-binding fragment may contain one or more CDRs from a specific human antibody, and is transferred to a framework region from one or more different human antibodies. The "Fab" fragment of an antibody refers to the portion of the antibody molecule that is composed of a light chain (including a variable region and a constant region) and a variable region and a constant region of a heavy chain that are bound by disulfide bonds. "Fab '" fragment refers to a Fab fragment that contains a portion of the hinge region. "F (ab ')₂ "Means a dimer of Fab. The "Fc" of an antibody refers to the portion of the antibody composed of the second and third constant regions of the heavy chain bound via a disulfide bond. The Fc portion of the antibody is responsible for many different effector functions such as ADCC and CDC, but does not participate in antigen binding. The "Fv" segment of an antibody refers to the smallest antibody fragment that contains a complete antigen-binding site. The Fv fragment consists of a variable region of a light chain and a variable region of a heavy chain. A "single-chain Fv antibody" or "scFv" refers to an engineered antibody in which the light chain variable region and the heavy chain variable region are directly connected or connected by a peptide chain (Huston JS et al., Proc Natl Acad Sci USA, 85: 5879 (1988)). "Single-chain antibody Fv-Fc" or "scFv-Fc" refers to an engineered antibody composed of scFv linked to the Fc segment of an antibody. "Camelized single domain antibody," "heavy chain antibody," or "HCAb (Heavy-chain-only antibodies, HCAb)" all mean two V_H Domain without light chain antibodies (Riechmann L. and Muyldermans S., J Immunol Methods. December 10; 231 (1-2): 25-38 (1999); Muyldermans S., J Biotechnol. June; 74 (4): 277-302 (2001); WO94 / 04678; WO94 / 25591; U.S. Patent No. 6,005,079). Heavy chain antibodies were originally derived from the camel family (camel, dromedary, and llama). Although the light chain is missing, camelized antibodies have a proven function of antigen binding (Hamers-Casterman C. et al., Nature. June 3; 363 (6428): 446-8 (1993); Nguyen VK. Et al., "Heavy-chain antibodies in Camelidae; a case of evolutionary innovation," Immunogenetics. April; 54 (1): 39-47 (2002); Nguyen VK. Et al., Immunology. May; 109 (1) : 93-101 (2003)). The variable region (VHH domain) of a heavy chain antibody is the smallest known binding unit produced by acquired immunity (Koch-Nolte F. et al., FASEB J. November; 21 (13): 3490-8. Electronics Edition June 15, 2007 (2007)). A "nano antibody" refers to an antibody fragment consisting of a VHH domain from a heavy chain antibody and two constant regions, CH2 and CH3. A "diabody" includes a small antibody fragment with two antigen-binding sites, where the fragment contains Vs linked on the same polypeptide chain_H Domain and V_L Domain (V_H -V_L Or V_H -V_L ) (See Holliger P. et al., Proc Natl Acad Sci U S A. Jul 15; 90 (14): 6444-8 (1993); EP404097; WO93 / 11161). The adapter between the two domains is very short, so that the two domains on the same chain cannot be paired with each other, thus forcing the two domains to pair with the complementary domains of the other chain to form two antibody binding sites. These two antibody binding sites can be targeted to bind the same or different antigens (or epitopes of the antigen). A "domain antibody" refers to an antibody fragment that contains only one heavy chain variable region or one light chain variable region. In some cases, two or more V_H Domains are covalently bound by a polypeptide adapter and form a bivalent domain antibody. Two Vs of a bivalent domain antibody_H Domains can target the same or different antigens. In some embodiments, "(dsFv)₂ "Contains three peptide chains: two V_H The groups are connected by a peptide adaptor, and are connected to two Vs by a disulfide bond._L Group bonding. In certain embodiments, a "bispecific ds bifunctional antibody" contains V_L1 -V_H2 (Connected by a peptide adapter) and V_H1 -V_L2 (Also connected by a peptide adapter), the two are at V_H1 And V_L1 It is bound by disulfide bonds. "Bispecific dsFv" or "dsFv-dsFv" contains three polypeptide chains: V_H1 -V_H2 Group, in which the heavy chains of the two are connected by a peptide linker (such as a long elastic linker), and are respectively linked to V by a disulfide bond_L1 And V_L2 Group binding, each pair of heavy chain light chains paired by disulfide bonds has different antigen specificity. In some embodiments, the "scFv dimer" is a bivalent bifunctional antibody or a bivalent single chain antibody (BsFv), which contains two dimerized Vs._H -V_L (Connected by a peptide adaptor) a group in which the V of one of the groups_H V with another group_L Cooperate to form two binding sites. These two binding sites can be targeted to bind the same antigen (or epitope of an antigen) or different antigens (or epitopes of an antigen). In other embodiments, the "scFv dimer" is a bispecific bifunctional antibody that contains interconnected V_L1 -V_H2 (Connected by peptide adapter) and V_H1 -V_L2 (Connected by a peptide adaptor), where V_H1 And V_L1 Collaboration, V_H2 And V_L2 Collaboration, and each collaboration has a different antigen specificity. The term "humanized" as used in this application, when used in antibodies or antigen-binding fragments, refers to CDRs derived from non-human animals, FR regions derived from humans, and constant regions derived from humans (when applicable) ) Antibodies or antigen-binding fragments. Because humanized antibodies or antigen-binding fragments have reduced immunogenicity, they can be used as human therapeutics in certain embodiments. In some embodiments, the non-human animal is a mammal, such as a mouse, rat, rabbit, goat, sheep, guinea pig, or hamster. In some embodiments, the humanized antibody or antigen-binding fragment consists essentially of human-derived sequences except that the CDR sequences are of non-human origin. In some embodiments, the human-derived FR region may include the same amino acid sequence as the human antibody from which it is derived, or it may include some amino acid changes, for example, no more than 10, 9, 8, 7, , 6, 5, 4, 3, 2 or 1 amino acid change. In some embodiments, the amino acid alteration may be present only in the heavy chain FR region, only in the light chain FR region, or in both chains. In some preferred embodiments, the humanized antibodies include human-derived FR1-3 and human-derived JH and Jκ. The term "chimeric" as used in this application refers to an antibody or antigen-binding fragment having a portion of the heavy and / or light chain derived from one species and the rest of the heavy and / or light chain derived from a different species . In an illustrative example, a chimeric antibody may include a constant region derived from a human and a variable region derived from a non-human animal, such as a mouse. The "PCSK9" used in the present application refers to the preprotein converting enzyme subtilisin Kexin type 9, which is a natural human preprotein converting enzyme belonging to the protease K subfamily of the secreted subtilisin family. PCSK9 is synthesized as lysogen, undergoes autocatalytic intramolecular processing in the endoplasmic reticulum, and is considered to function as a preprotein converting enzyme. PCSK9 plays a key role in regulating cholesterol levels in the blood. PCSK9's functionally acquired (such as S127R, F216L, and D374Y) mutations may be associated with an autosomal dominant inherited familial hypercholesterolemia, in which the PCSK9 mutation increases LDL receptor levels (see, for example, Burnett and Hooper, Clin Biochem Rev (2008) 29 (1): 11-26, Benjannet et al. J. Biol. Chem., (2004) 279 (47): 48865-48875 and Fasano T et al., Atherosclerosis. (2009) 203 (1): 166 -71). A representative amino acid sequence of human-derived PCSK9 is disclosed by GenBank accession number NP_777596.2, and a representative nucleic acid sequence encoding the human-derived PCSK9 is disclosed by GenBank accession number FJ525880.1. In certain embodiments, the term PCSK9 includes a post-translationally modified PCSK9 molecule of the PCSK9 amino acid sequence, such as a glycosylated, PEGylated PCSK9 sequence, a PCSK9 sequence with its signal sequence cleaved, or an autocatalytic domain The PCSK9 sequence is cleaved off from its pro domain but is not separated from the catalytic domain. "LDL-C" used herein refers to low density lipoprotein cholesterol, and "HDL-C" refers to high density lipoprotein cholesterol. LDL and HDL belong to 5 major lipoprotein groups: chylomicrons, very low density lipoprotein (VLDL), intermediate density lipoprotein (IDL), low density lipoprotein and high density lipoprotein (HDL) (in order of arrogance) Granules to the most dense (smallest particles). LDL (particle-containing "bad" cholesterol) is able to transport lipid / sterol molecules such as cholesterol (ie LDL-C) to the arterial wall, attracting macrophages and thus inducing arteries Atherosclerosis. In contrast, HDL (particles containing "good" cholesterol) can automatically remove lipid molecules, such as cholesterol (ie HDL-C), from macrophages on the vein wall. Therefore, a high level of LDL-C is the heart Major risks of vascular disease (CVD), such as peripheral arterial disease, coronary artery disease (CAD, such as angina pectoris, myocardial infarction (commonly known as heart disease), hyperlipidemia, hypercholesterolemia, hypertriglyceridemia), arteries Atherosclerosis, Stroke, Hypertensive heart disease, Rheumatic heart disease, Cardiomyopathy, Arrhythmia, Congenital heart disease, Heart valve disease, Myocarditis, Aortic aneurysm, Peripheral artery disease, Obesity, Hepatobiliary disease, Kidney disease syndrome, Hypothyroidism Venous thrombosis. "LDL-R" or "LDL receptor" used in this application is a cell surface chimeric protein with 839 amino acids (after removing 21 signal peptides of amino acids), which mediates LDL-C is endocytosed and LDL-C is removed from the blood. A representative amino acid sequence of human LDL-R is disclosed by GenBank accession number P01130.1, and it encodes a representative mRNA nucleic acid of human LDL-R The sequence is revealed by GenBank accession number NM_000527.4. When PCSK9 binds to the LDL receptor, the antibody is destroyed and LDL-C cannot be removed from the blood. Conversely, when PCSK9 is blocked, there will be More LDL receptors and more LDL cholesterol will be removed from the blood. "Anti-PCSK9 antibody" used in this application refers to an antibody capable of specifically binding to PCSK9 (such as human or monkey PCSK9), which is sufficient to provide diagnosis and Affinity for therapeutic use. "Specific binding" or "specific binding" in this application refers to a non-random binding reaction between two molecules, such as a reaction between an antibody and an antigen. In some embodiments In the present application, the antibody or antigen-binding fragment thereof specifically binds to human and / or monkey PCSK9. And binding affinity (K_D ) ≤10^-6 M (eg: ≤5 × 10^-7 M, ≤2 × 10^-7 M, ≤10^-7 M, ≤5 × 10^-8 M, ≤2 × 10^-8 M, ≤10^-8 M, ≤5 × 10^-9 M, ≤2 × 10^-9 M, ≤10^-9 M, ≤10^-10 M). KD in this application refers to the ratio (koff / kon) of dissociation speed to binding speed, which can be measured by surface plasmon resonance (SPR) method, for example, using an instrument such as Biacore. The ability to "block binding" or "competitively identical epitopes" in this application means that the antibody or its antigen-binding fragment inhibits the interaction between two molecules (such as human PCSK9 and anti-PCSK9 antibodies) to Any detectable ability. In certain embodiments, an antibody or antigen-binding fragment that blocks binding between two molecules can inhibit the interaction between the binding between two molecules by at least 50%. In certain embodiments, such inhibition can be greater than 60%, greater than 70%, greater than 80%, or greater than 90%. The "antigenic determinant region" used in this application refers to the portion of the amino acid or atomic group of the antigen molecule that is bound to the antibody. If two antibodies show competitive binding to an antigen, they may bind the same epitope on the antigen. For example, if the antibodies or antigen-binding fragments thereof provided in the present application block exemplary antibodies, such as 2.6.6, 2.12.12.4, 2.6.6-z4-uIgG1k, 2.12.12.4-z1-IgG4k, 2.12.12.4-z2-IgG4k , 2.12.12.4-z4-uIgG4k, 2.12.12.4-v2-z4-uIgG4k binding to human PCSK9, the antibodies or antigen-binding fragments thereof can be regarded as binding the same epitope with their exemplified antibodies. The symbols used in the antibody names used in this application have different meanings: "uIgG4" refers to antibodies with human IgG4 isotype constant regions, such as uIgG1 and uIgG2 refer to antibodies with human IgG1 and IgG2 isotype constant regions, respectively; " "Z" refers to a humanized antibody, z1, z2, z4, etc. refer to different versions of the humanized antibody; "K" or "L" refers to the use of a kappa light chain or a lambda light chain for the antibody. "2.6.6" as used herein refers to a mouse monoclonal antibody having a heavy chain variable region as shown in SEQ ID NO: 36 and a light chain variable region as shown in SEQ ID NO: 38. "2.6.6-z4-uIgG1k" as used in this application refers to a humanized monoclonal antibody of 2.6.6, which has a heavy chain variable region as shown in SEQ ID NO: 48, as shown in SEQ ID NO: 50 The light chain variable region and the human IgG1 isotype constant region are shown. "2.12.12.4" as used herein refers to a mouse monoclonal antibody having a heavy chain variable region as shown in SEQ ID NO: 40 and a light chain variable region as shown in SEQ ID NO: 42. The "2.12.12.4-z4-uIgG4k" used in this application refers to the humanized monoclonal antibody of 2.12.12.4 of the fourth edition, which has a constant region of human IgG4 isotype. 2.12.12.4-z1-IgG4K and 2.12.12.4-z2-IgG4K are different versions of the humanized monoclonal antibodies of 2.12.12.4 (ie, the first and second versions). "2.12.12.4-v2-z4-uIgG4k" used in this application refers to an engineered humanized monoclonal antibody based on 2.12.12.4-z4-uIgG4k with two amino acid mutations (D30E and N85D), It has a heavy chain variable region as shown in SEQ ID NO: 44, a light chain variable region as shown in SEQ ID NO: 46, and a human IgG4 isotype constant region. In the present application, when "conservative substitution" is used for an amino acid sequence, it means that one amino acid residue is replaced with another amino acid residue having a side chain with similar physicochemical properties. For example, between hydrophobic side chain amino acid residues (e.g. Met, Ala, Val, Leu and Ile), neutral hydrophilic side chain residues (e.g. Cys, Ser, Thr, Asn and Gln), acidic side chains Conservative substitutions are made between residues (such as Asp, Glu), basic side chain amino acids (such as His, Lys, and Arg) or directional side chain residues (such as Trp, Tyr, and Phe). It is known in the art that conservative substitutions usually do not cause significant changes in the conformational structure of the protein and are therefore able to retain the biological activity of the protein. When "percent sequence identity" is used for an amino acid sequence (or nucleic acid sequence), it refers to a candidate sequence after sequence alignment, and if necessary, introducing a gap to maximize the number of identical amino acids (or nucleic acids). In this example, the percentage of amino acid (or nucleic acid) residues in the candidate sequence is the same as that of the reference sequence. Conservative substitutions of the amino acid residues may or may not be considered the same residue. Tools that can be revealed by this technology, such as BLASTN, BLASTp (National Center for Biotechnology Information (NCBI), see also, Altschul SF et al., J. Mol. Biol., 215: 403-410 (1990) Stephen F. et al., Nucleic Acids Res., 25: 3389-3402 (1997)), ClustalW2 (European Bioinformatics Institute website, see, Higgins DG et al., Methods in Enzymology, 266: 383-402 (1996 ); Larkin MA et al., Bioinformatics (Oxford, England), 23 (21): 2947-8 (2007)) and ALIGN or Megalign (DNASTAR) software to align sequences to determine amino acid (or nucleic acid) sequences Percent sequence identity. Those skilled in the art can use the default parameters of the tool or adjust the parameters appropriately according to the needs of the comparison, for example, by selecting a suitable algorithm. "Effective function" as used in this application refers to the biological activity of the antibody's Fc region bound to its effectors such as the C1 complex and Fc receptor. Exemplary effector functions include complement-dependent cytotoxicity (CDC) induced by the interaction of antibodies with C1q on the C1 complex, antibody-dependent cell-mediated cells induced by binding of the Fc region of the antibody to Fc receptors on effector cells Toxicity (ADCC) and phagocytosis. "Treatment" or "therapy" of a condition includes preventing or reducing a condition, reducing the rate at which a condition arises or developing, reducing the risk of developing a condition, preventing or delaying the development of symptoms associated with a condition , Reduce or terminate the symptoms associated with a condition, produce a complete or partial reversal of a condition, cure a condition, or a combination of the above. "Isolated" matter has been artificially changed from its natural state. If some "isolated" substance or component appears in nature, it has changed or left its original state, or both. For example, a polynucleotide or polypeptide naturally occurring in a living animal is not isolated, but if the polynucleotide or polypeptide is sufficiently separated from the substances that coexist in its natural state and exists in a sufficiently pure state, Can be considered "separated." In certain embodiments, the purity of the antibodies and antigen-binding fragments is at least 90%, 93%, 95%, 96%, 97%, 98%, 99%, which are determined by electrophoresis methods (such as SDS-PAGE, isoelectric focusing) , Capillary electrophoresis), or chromatography (such as ion exchange chromatography or reversed-phase HPLC). The "vector" in the present invention refers to a vehicle that can be operatively inserted into a polynucleotide encoding a protein, and the protein can be expressed. Vectors can be used to transform, transduce, or transfect host cells so that the genetic material elements they carry are expressed within the host cells. For example, vectors include: plasmids, phagemids, cosmids, artificial chromosomes such as yeast artificial chromosomes (YAC), bacterial artificial chromosomes (BAC) or P1-derived artificial chromosomes (PAC), phages such as lambda phage or M13 phage , And animal viruses. Animal viruses used as vectors include retroviruses (including lentiviruses), adenoviruses, adeno-associated viruses, herpes viruses (such as herpes simplex virus), poxviruses, baculoviruses, papillomaviruses, and papillomaviruses (Such as SV40). Vectors can contain a variety of performance-controlling elements, including promoter sequences, transcription initiation sequences, enhancer sequences, selection elements, and reporter genes. Alternatively, the vector may contain a replication initiation site. A vector can also include components that assist it in entering cells, including, but not limited to, viral particles, liposomes, or protein shells. A "host cell" in the present invention refers to a cell that is introduced into an exogenous polynucleotide and / or vector. In the present invention, "a disease or symptom mediated by PSCK9" refers to a disease or symptom caused or characterized by a change in PCSK9, such as a change in performance level, activity, and / or the presence of a variant or mutation of PCSK9. Examples of diseases or conditions mediated by PCSK9 include, but are not limited to, dyslipidemia, hyperlipoproteinemia, hyperlipidemia; dyslipidemia; hypercholesterolemia, heart disease, stroke, coronary heart disease, atherosclerosis , Peripheral vascular disease, claudication, type II diabetes, hypertension, cardiovascular disease or condition, inflammation or autoimmune disease. Methods for identifying / diagnosing the above-mentioned diseases or symptoms are known in the art. For the use of the antibody or antigen-binding fragment thereof in the treatment of CVD (such as acute myocardial infarction (AMI), acute coronary syndrome (ACS), stroke and cardiovascular death), the "therapeutically effective amount" or "Effective dose" means the antibody or antigen binding thereof that is capable of reducing lipids (such as cholesterol) in plasma or serum, alleviating symptoms or markers associated with a CVD condition, preventing or delaying the development of a CVD condition, or a combination thereof. The dose or concentration of the fragment. "Pharmaceutically acceptable" means the carrier, solvent, diluent, excipient, and / or salt referred to, generally chemically and / or physically compatible with other ingredients in the formulation, and physiologically compatible with Recipient compatible.anti- -PCSK9 antibody In certain embodiments, the application provides exemplary humanized monoclonal antibodies 2.6.6, 2.12.12.4, 2.6.6-z4-uIgG1k, 2.12.12.4-z1-IgG4k, 2.12.12.4-z2-IgG4k , 2.12.12.4-z4-uIgG4k and 2.12.12.4-v2-z4-uIgG4k, the CDR sequences of which are shown in Table 1, and the heavy or light chain variable regions of their mouse parental antibodies and humanized antibodies The sequences are also listed below.table 1 2.6.6-VH ( Mouse antibody ) Amino acid sequence (SEQ ID NO: 36): Nucleic acid sequence (SEQ ID NO: 37) 2.6.6 - VL ( Mouse antibody ) Amino acid sequence (SEQ ID NO: 38): Nucleic acid sequence (SEQ ID NO: 39) 2.12.12.4-VH ( Mouse antibody ) Amino acid sequence (SEQ ID NO: 40): Nucleic acid sequence (SEQ ID NO: 41) 2.12.12.4-VL ( Mouse antibody ) Amino acid sequence (SEQ ID NO: 42) Nucleic acid sequence (SEQ ID NO: 43) 2.12.12.4-v2-z4-uIgG4k-VH ( Engineered humanized antibodies, D30E and N85D) Amino acid sequence (SEQ ID NO: 44): Nucleic acid sequence (SEQ ID NO: 45) 2.12.12.4-v2-z4-uIgG4k-VL ( Engineered humanized antibodies, D30E and N85D) Amino acid sequence (SEQ ID NO: 46): Nucleic acid sequence (SEQ ID NO: 47) 2.6.6-v2-z4-uIgG1k-VH Amino acid sequence (SEQ ID NO: 48): Nucleic acid sequence (SEQ ID NO: 49) 2.6.6-v2-z4-uIgG1k-VL Amino acid sequence (SEQ ID NO: 50): Nucleic acid sequence (SEQ ID NO: 51) In some embodiments, one or more of the CDR sequences described herein can be modified or altered so that the obtained antibody is improved in one or more properties relative to the original antibody (e.g., improved antigen binding, improved Glycosylation pattern, reduced risk of glycosylation on CDR residues, increased pharmacokinetic half-life, pH sensitivity, and compatibility with conjugation), or equivalent to the original antibody (i.e., except for the modifications and Change the antibody with the same CDR sequence outside), or at least substantially retain the antigen-binding properties of the original antibody. Those skilled in the art will understand that the CDR sequences provided in Table 1 can be modified to include substitutions of one or more amino acids, thereby resulting in improved biological activity such as improved binding affinity to human PCSK9. For example, phage display technology can be used to produce and express a library of antibody variants (such as Fab or FcFv variants), followed by screening for antibodies that have an affinity for human PCSK9. In another example, computer software can be used to simulate the binding of the antibody to human PCSK9 and identify the amino acid residues on the antibody that form the binding interface. Substitution of these residues can be avoided to prevent a decrease in binding affinity, or these residues can be targeted for substitution to form stronger binding. In certain embodiments, at least one (or all) of the CDR sequences are substituted by conservative substitutions. In certain embodiments, the antibodies and antigen-binding fragments include one or more CDR sequences having at least 80% (e.g., at least 85%, 88%, 90%, 91%) of the sequences listed in Table 1. %, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%), while retaining similarity to or even higher than its parental antibody to human PCSK9 Binding affinity, the parent antibodies have substantially the same sequence, but their corresponding CDR sequences have 100% sequence identity with the sequences listed in Table 1. In certain embodiments, the anti-PCSK9 antibodies and antigen-binding fragments thereof are humanized. These humanized antibodies retain the binding affinity to human PCSK9, preferably with exemplary antibodies: 2.6.6, 2.12.12.4, 2.6.6-z4-uIgG1k, 2.12.12.4-z1-IgG4k, 2.12. The levels of 12.4-z2-IgG4k, 2.12.12.4-z4-uIgG4k and 2.12.12.4-v2-z4-uIgG4k are similar. This application also includes antibodies and antigen-binding fragments thereof that compete with the anti-PCSK9 antibody and its antigen-binding fragments of the application for the same epitope. In certain embodiments, the antibody is less than 10^-6 M, below 10^-7 M, below 10^-7.5 M, below 10^-8 M, below 10^-8.5 M or below 10^-9 M or below 10^-10 M's IC₅₀ Value (i.e. half inhibitory concentration) blocks 2.6.6, 2.12.12.4, 2.6.6-z4-uIgG1k, 2.12.12.4-z1-IgG4k, 2.12.12.4-z2-IgG4k, 2.12.12.4-z4-uIgG4k or 2.12.12.4 Binding of v2-z4-uIgG4k to human or monkey PCSK9. IC₅₀ Values are determined by competitive tests such as ELISA and radioligand competition binding assays. In some embodiments, the anti-PCSK9 antibodies and antigen-binding fragments thereof described herein can be^-8 M, not more than 10^-9 M or not more than 10^-10 M (e.g. ≤1.1 × 10^-9 M, ≤2 × 10^-9 M, ≤10^-9 M, ≤5.5 × 10^-10 M, ≤4.5 × 10^-11 M, ≤5.5 × 10^-11 M) The binding affinity (Kd) specifically binds to human PCSK9, which is measured by surface plasmon resonance binding method or ELISA. Binding affinity available K_D The value indicates that it was calculated from the ratio of the dissociation rate to the binding rate (koff / kon) when the binding of the antigen and the antigen-binding molecule reached equilibrium. The antigen-binding affinity (e.g., K_D ) Can be suitably determined by suitable methods known in the art, which include the use of instruments such as surface plasmon resonance binding methods such as Biacore (see, for example, Murphy, M. et al., Current protocols in protein science, Chapter Chapter 19, Unit 19.14, 2006). In certain embodiments, the antibodies and antigen-binding fragments thereof described herein and human PCSK9 are 0.05nM-1nM (e.g., 0.1nM-0.9nM, 0.1nM-0.8nM, 0.1nM-0.7nM, 0.1nM-0.6). nM, 0.1nM-0.5nM, 0.1nM-0.4nM, 0.1nM-0.3nM, or 0.1nM-0.2nM) EC50 (ie, half binding concentration). The binding of the antibody to human PCSK9 can be determined by methods known in the art, such as the sandwich method, such as ELISA, Western blot, or other binding tests. In an illustrative example, the test antibody (that is, the primary antibody) is bound to the immobilized human PCSK9, and then the unbound antibody is washed away, and a labeled secondary antibody is introduced, which can bind to the primary antibody and therefore can detect the bound primary antibody. anti. The detection can be performed on a microplate reader when using immobilized PCSK9. In certain embodiments, the antibodies and antigen-binding fragments thereof described herein have an IC of 3nM-10nM (e.g., 3.5nM-9.5nM, 3.5nM-8.5nM, or 5nM-8.5nM).₅₀ Inhibits the binding of human PCSK9 to its ligand, which is measured by a competitive test. In certain embodiments, the antibodies and antigen-binding fragments thereof bind to monkey PCSK9 with similar binding affinity to human PCSK9. For example, exemplary antibodies 2.6.6, 2.12.12.4, 2.6.6-z4-uIgG1k, 2.12.12.4-z1-IgG4k, 2.12.12.4-z2-IgG4k, 2.12.12.4-z4-uIgG4k, and 2.12.12.4-v2 -z4-uIgG4k with monkey PCSK9 with similar affinity or EC to human PCSK9₅₀ Value combination. In some embodiments, the anti-PCSK9 antibody and its antigen-binding fragment also include an immunoglobulin constant region. In some embodiments, the immunoglobulin constant regions include heavy and / or light chain constant regions. The heavy chain constant region includes a CH1, CH1-CH2, or CH1-CH3 region. In some embodiments, the constant region may also include one or more modifications to obtain the desired properties. For example, the constant region can be modified to reduce or deplete one or more effector functions, to enhance FcRn receptor binding, or to introduce one or more cysteine residues. In some embodiments, the anti-PCSK9 antibodies and antigen-binding fragments thereof have a constant region of the IgG4 isotype, which has a reduced or depleted effector function. Many tests are known to evaluate ADCC or CDC activity, such as Fc receptor binding assay, complement C1q binding assay, and cell lysis method, and those skilled in the art can easily choose. In some embodiments, the antibodies and antigen-binding fragments thereof can be used as a base molecule for antibody-drug conjugates, bispecific or multivalent antibodies. The anti-PCSK9 antibody and the antigen-binding fragment thereof described in the present application may be a monoclonal antibody, a polyclonal antibody, a fully human antibody, a humanized antibody, a chimeric antibody, a recombinant antibody, a bispecific antibody, a labeled antibody, a secondary antibody Valent antibody or anti-idiotypic antibody. Recombinant antibodies are antibodies made in vitro using recombinant methods rather than animals. Bispecific antibodies or bivalent antibodies are artificial antibodies with fragments of two different monoclonal antibodies, which are capable of binding two different antigens. "Bivalent" antibodies and their antigen-binding fragments include two antigen-binding sites. The two antigen-binding sites may bind the same antigen, or may each bind to a different antigen, in which case the antibody or antigen-binding fragment is "bispecific". In some embodiments, the anti-PCSK9 antibodies and antigen-binding fragments thereof described herein are camelized single chain domain antibody, diabody, scFv, scFv dimer, BsFv, dsFv, (dsFv) 2, dsFv-dsFv ', Fv fragment, Fab, Fab', F (ab ') 2, ds diabody, nanobody, domain antibody or bivalent domain antibody. In certain embodiments, the anti-PCSK9 antibodies and antigen-binding fragments thereof further comprise a conjugate. It is envisaged that the antibodies or antigen-binding fragments thereof of the present invention may be linked to a variety of conjugates (see, for example, "Conjugate Vaccines", Contributions to Microbiology and Immunology, JM Cruse and RE Lewis, Jr. (eds.), Carger Press, New York, (1989)). These conjugates can be linked to the antibody or antigen conjugate by other means such as covalent binding, affinity binding, intercalation, coordinate binding, mismatch, binding, mixing, or addition. In certain embodiments, the antibodies and antigen-binding fragments disclosed herein can be engineered to contain specific sites other than the epitope-binding portion, and these sites can be used to bind one or more conjugates. For example, such sites may contain one or more reactive amino acid residues, such as cysteine residues and histidine residues, to assist in covalent attachment to the conjugate. In certain embodiments, the antibody may be attached to the conjugate indirectly, or through another conjugate. For example, the antibody or antigen-binding fragment thereof can bind biotin and then indirectly bind a second conjugate, which is linked to avidin. The conjugate can be a detectable label, a pharmacokinetic modification moiety, a purification moiety, or a cytotoxic moiety. Examples of detectable labels may include fluorescent labels (e.g., luciferin, rhodamine, salamander, phycoerythrin, or Texas red), enzyme-substance labels (e.g., horseradish peroxidase, Alkaline phosphatase, luciferase, glucoamylase, lysozyme, sugar oxidase or β-D-galactosidase), radioisotopes (e.g.,¹²³ I,¹²⁴ I,¹²⁵ I,¹³¹ I,³⁵ S,³ H,¹¹¹ In,¹¹² In,¹⁴ C,⁶⁴ Cu,⁶⁷ Cu,⁸⁶ Y,⁸⁸ Y,⁹⁰ Y,¹⁷⁷ Lu,²¹¹ At,¹⁸⁶ Re,¹⁸⁸ Re,¹⁵³ Sm,²¹² Bi, and³² P, other lanthanides, luminescent labels), chromophore moieties, digoxin, biotin / avidin, DNA molecules or gold for detection. In certain embodiments, the conjugate may be a pharmacokinetic modification moiety such as PEG, which helps extend the half-life of the antibody. Other suitable polymers include, for example, carboxymethyl cellulose, dextran, polyvinyl alcohol, polyvinyl pyrrolidone, ethylene glycol / propylene glycol copolymers, and the like. In certain embodiments, the conjugate can be a purified moiety, such as a magnetic bead. A "cytotoxic moiety" may be any agent that is harmful to the cell or that may damage or kill the cell. Examples of cytotoxic moieties include, but are not limited to, paclitaxel, cytochalasin B, gramicidin D, ethidium bromide, tuematine, mitomycin, etoposide, teniposide, vincristine, Vinblastine, colchicine, doxorubicin, daunorubicin, dihydroxy anthracin dione, mitoxantrone, mithromycin, actinomycin D, 1-dehydrotestosterone, glucocorticoids, general Lucaine, tetracaine, lidocaine, propranolol, puromycin and its analogs, antimetabolites (e.g., methotrexate, 6-mercaptopurine, 6-thioguanine, arabinocytosine Glycosides, 5-fluorouracil dacarbaba), alkylating agents (e.g., nitrogen mustard, cetipine phenylbutyrate, melphalan, carmustine (BSNU) and lomustine (CCNU), cyclophosphamide , Busulfan, dibromomannitol, streptozotocin, mitomycin C, and cis-dichlorodiamine platinum (II) (DDP) cisplatin), anthracycline antibiotics (e.g. daunorubicin (previously Daunomycin) and doxorubicin), antibiotics (such as dactinomycin (formerly known as actinomycin), bleomycin, mithromycin, and anthromycin (AMC)), and antimitotic agents ( Vincristine and vinblastine Pristine).Multi-core Glycylic acid and recombination method The application provides isolated polynucleotides encoding anti-PCSK9 antibodies and antigen-binding fragments thereof. In certain embodiments, the isolated polynucleotide includes one or more nucleotide sequences as in Table 1, which encode the CDR sequences as in Table 1. In some embodiments, the isolated polynucleotide encodes a heavy chain variable region and includes a sequence selected from the group consisting of SEQ ID NO: 26, SEQ ID NO: 30, SEQ ID NO: 34, and having Homologous sequences with at least 80% (e.g., at least 85%, 88%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%) of sequence identity . In some embodiments, the isolated polynucleotide encodes a light chain variable region and includes a sequence selected from the group consisting of SEQ ID NO: 28, SEQ ID NO: 32, SEQ ID NO: 36, and having Homologous sequences with at least 80% (e.g., at least 85%, 88%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%) of sequence identity . In certain embodiments, the percentage of identity is derived from the degeneracy of the genetic code, while the encoded protein sequence remains unchanged. Using recombinant techniques known in the art, a vector including a polynucleotide encoding the anti-PCSK9 antibody and its antigen-binding fragment (for example, including the sequence shown in Table 1) can be introduced into a host cell for selection (amplification) DNA) or gene expression. In another embodiment, the antibody can be produced by homologous recombination methods known in the art. The DNA encoding the monoclonal antibody can be isolated and sequenced by conventional methods (for example, an oligonucleotide probe can be used, which can specifically bind to genes encoding the heavy and light chains of the antibody). A variety of vectors are available. Vector components typically include, but are not limited to, one or more of the following: a signal sequence, an origin of replication, one or more marker genes, an enhancement sequence, a promoter (e.g., SV40, CMV, EF-1α), and a transcription termination sequence . In some embodiments, the vector system includes mammals, bacteria, yeast systems, etc., and will include plasmids such as, but not limited to, pALTER, pBAD, pcDNA, pCal, pL, pET, pGEMEX, pGEX, pCI, pCMV, pEGFP, pEGFT, pSV2, pFUSE, pVITRO, pVIVO, pMAL, pMONO, pSELECT, pUNO, pDUO, Psg5L, pBABE, pWPXL, pBI, p15TV-L, pPro18, pTD, pRS420, pLexA, pACT2 and others are available from the laboratory Or a commercially available carrier. Suitable vectors may include plasmid or viral vectors (eg, replication defective retroviruses, adenoviruses and adeno-associated viruses). Vectors including polynucleotides encoding the antibodies and antigen-binding fragments thereof can be introduced into host cells for selection or gene expression. The host cells suitable for colonizing or expressing the DNA in the vector in the present invention are prokaryotic cells, yeast, or the above-mentioned higher eukaryotic cells. Prokaryotic cells suitable for use in the present invention include Eubacteria such as Gram-negative or Gram-positive bacteria, for example, Enterobacteriaceae, such as E. coli, Enterobacter, Erwinia, Klebsiella Genus, Proteus, Salmonella, such as Salmonella typhimurium, Serratia, such as Serratia marcescens, and Shigella, and Bacillus, such as Bacillus subtilis and lichen Bacillus, Pseudomonas such as Pseudomonas aeruginosa and Streptomyces. In addition to prokaryotic cells, eukaryotic microorganisms such as filamentous fungi or yeasts can also be used as host cells to colonize or express vectors encoding anti-PCSK9 antibodies. Saccharomyces cerevisiae, or baker's yeast, are the most commonly used lower eukaryotic host microorganisms. However, many other genera, species, and strains are commonly used and applicable in the present invention, such as Schizosaccharomyces pombe; Kluyveromyces hosts, such as Kluyveromyces lactis, Kluyveromyces fragilis (ATCC 12,424) Kluyveromyces bulgaricus (ATCC 16,045), Kluyveromyces welchii (ATCC 24,178), Kluyveromyces kluyveri (ATCC 56,500), Kluyveromyces drosophila (ATCC 36,906), Kluyveromyces thermotolerance and Markske Ruwiomyces; Yarrowia lipolytica (EP 402,226); Pichia pastoris (EP 183,070); Candida; Trichoderma reesei (EP 244,234); Streptomyces; Western Schwann yeast, such as: Western Schwann yeast; and filamentous fungi, such as: Neurospora, Penicillium, Curvularia and Aspergillus, such as Aspergillus nidulans and Aspergillus niger. The host cells provided in the present invention and suitable for expressing glycosylated antibodies or antigen-binding fragments thereof are derived from multicellular organisms. Examples of invertebrate cells include plant and insect cells. A variety of baculoviral strains and their variants and corresponding permissive insect host cells have been discovered from hosts such as Spodoptera frugiperda (caterpillar), Aedes aegypti (mosquito) , Aedes albopictus (mosquito), Drosophila melanogaster (Drosophila) and silkworm. A number of virus strains for transfection are publicly available, such as the Bm-5 variants of Spodoptera litura nuclear polyhedrosis virus and Bombyx mori nuclear polyhedrosis virus. These viruses can be used in the present invention, especially For transfection of Spodoptera frugiperda cells. Plant cell cultures of cotton, corn, potatoes, soybeans, petunias, tomatoes and tobacco can also be used as hosts. However, spinal cells are of most interest, and the culture (tissue culture) of spinal cells has become a well-known operation. Examples of mammalian host cells that can be used are: SV40 transformed monkey kidney cell CV1 line (COS-7, ATCC CRL 1651); human embryonic kidney cell line (293 or subculture 293 cell suspension line, Graham et al., J. Gen. Virol. 36:59 (1977)); young hamster kidney cells (BHK, ATCC CCL 10); Chinese hamster ovary cells / -DHFR (CHO, Urlaub et al., Proc. Natl. Acad. Sci. USA 77: 4216 ( 1980)); mouse testis support cells (TM4, Mather, Biol. Reprod. 23: 243-251 (1980)); monkey kidney cells (CV1 ATCC CCL 70); African green monkey kidney cells (VERO-76, ATCC CRL -1587); human cervical cancer cells (HELA, ATCC CCL 2); canine kidney cells (MDCK, ATCC CCL 34); Buffalo rat liver cells (BRL 3A, ATCC CRL 1442); human lung cells (W138, ATCC CCL 75); human hepatocytes (Hep G2, HB 8065); mouse breast tumors (MMT 060562, ATCC CCL51); TRI cells (Mather et al., Annals NY Acad. Sci. 383: 44-68 (1982)); MRC 5 cells; FS4 cells; and human liver cancer cell lines (Hep G2). In certain preferred embodiments, the host cell is a 293F cell. The host cell is transformed with the expression or selection vector capable of producing anti-PCSK9 antibody as described above, and cultured in a conventional nutrient medium, which is modified to be suitable for inducing a promoter, selecting transformed cells, or for encoding purposes Sequence of genes. The host cells used to produce the antibodies or antigen-binding fragments thereof in the present invention can be cultured in a variety of media. Commercially available media such as Ham's F10 (Sigma), minimum basic culture medium (MEM, (Sigma)), RPMI-1640 (Sigma), and Dulbecco's Modified Eagle's Medium (DMEM) (Sigma) can be used to culture the host cells. In addition, any of Ham et al., Meth. Enz. 58:44 (1979), Barnes et al., Anal. Biochem. 102: 255 (1980), U.S. Patent Nos. 4,767,704; 4,657,866; 4,927,762; 4,560,655; or 5,122,469; WO 90 / 03430; WO 87/00195; or the medium described in US Patent Application Re. 30,985 can be used as a medium for the host cell. These media can be supplemented with necessary hormones and / or other growth factors (such as insulin, transferrin or epidermal growth factor), salts (such as sodium chloride, calcium chloride, magnesium chloride, and phosphate), and buffers (such as HEPES), nucleotides (such as adenylate and thymine), antibiotics (such as gentamicin), trace elements (defined as inorganic compounds whose final concentration is usually in the micromolar range), and glucose or equivalent energy source. The medium may also contain any other necessary additives at appropriate concentrations known in the art. The conditions of the medium, such as temperature, pH, and the like, are the conditions previously used to select host cells for expression, and are well known to those skilled in the art. When using recombinant technology, the antibodies can be produced intracellularly, in the parietal space, or secreted directly into the culture medium. If the antibody is produced intracellularly, the host cell or particle debris of the lysed fragment is first removed, for example, by centrifugation or ultrasound. Carter et al., Bio / Technology 10: 163-167 (1992) describe a method for isolating antibodies secreted into the membrane space of E. coli. In short, the cell paste was opened in the presence of sodium acetate (pH 3.5), EDTA, and benzylsulfonium fluoride (PMSF) for about 30 minutes or more. Centrifuge to remove cell debris. If the antibody is secreted into the culture medium, a commercially available protein concentration filter, such as Amicon or Millipore Pellicon ultrafiltration unit, is usually first used to concentrate the supernatant of the performance system. Protease inhibitors such as PMSF can be added in any of the foregoing steps to inhibit protein degradation and antibiotics to prevent the growth of accidental contaminants. Antibodies produced from the cells can be purified using purification methods such as hydroxyapatite chromatography, gel electrophoresis, dialysis, DEAE-cellulose ion exchange chromatography columns, ammonium sulfate precipitation, salting out, and affinity chromatography Among them, affinity chromatography is the preferred purification technique. The type of antibody and the presence of any immunoglobulin Fc domain in the antibody determine whether protein A is suitable as an affinity ligand. Protein A can be used for purification of antibodies based on human γ1, γ2 or γ4 heavy chains (Lindmark et al., J. Immunol. Meth. 62: 1-13 (1983)). Protein G is suitable for all murine isomers and human gamma 3 (Guss et al., EMBO J. 5: 1567 1575 (1986)). Agarose is the most commonly used affinity ligand attachment matrix, but other matrices are also available. Mechanically stable matrices such as controlled-porosity glass or poly (styrene) benzene can achieve faster flow rates and shorter processing times than with agarose. If the antibody contains a CH3 domain, it can be purified using Bakerbond ABX.TM resin (J. T. Baker, Phillipsburg, N.J.). Other protein purification techniques such as fractionation in ion exchange columns, reversed-phase HPLC, silica gel chromatography, anion or cation exchange resin-based heparin agarose gel chromatography (such as Polyaspartic acid column), chromatography focus, SDS-PAGE, and ammonium sulfate precipitation. After any preliminary purification steps, low pH hydrophobic interaction chromatography can be used to treat mixtures containing antibodies and impurities of interest, using a wash buffer pH of about 2.5-4.5, preferably at low salt concentrations (e.g., (0 to 0.25 M salt concentration).Set The application provides a kit comprising the anti-PCSK9 antibody and its antigen-binding fragment. In some embodiments, the kit is used to detect the presence or level of PCSK9 in a biological sample. The biological sample may include serum. In some embodiments, the kit includes an anti-PCSK9 antibody conjugated to a detectable label and an antigen-binding fragment thereof. In some embodiments, the set includes unlabeled anti-PCSK9 antibodies and antigen-binding fragments thereof, and further includes a secondary antibody capable of binding a labeled anti-PCSK9 antibody and antigen-binding fragments thereof. The kit may further include instructions for use and packaging that separates the components in the kit. In some embodiments, the kit is used to treat, prevent, or delay a disease or condition mediated by PCSK9. In some embodiments, the anti-PCSK9 antibodies and antigen-binding fragments thereof are linked to a substrate or instrument for a sandwich assay such as an ELISA or immunochromatographic assay. Suitable substrates or instruments can be, for example, microplates and test strips. In some embodiments, the kit also includes one or more agents known to be beneficial for lowering cholesterol. Exemplary agents include statins, HMG-CoA reductase inhibitors other than statins, nicotinic acid (nicotinic acid), cholesterol absorption inhibitors, cholesterol ester transfer protein (CETP), bile acid sequestrants, fibrates, Phytosterols; or regulators selected from small molecule lipid / lipid concentration ratios, peptidomimetics, antisense RNA, small interfering RNA (siRNA), and natural or modified lipids. In some embodiments, the cholesterol absorption inhibitor is ezetimibe or SCH-48461; the CETP is evacetrapib, anacetrapib or dalcetrapib; the bile acid sequestrant is preferably colesevelam, cholestyramine or fibrate Ning is preferably fenofibrate, gemfibrozil, antrum, or benzabate; or a combination of the above agents.Pharmaceutical composition and treatment method The application further provides a pharmaceutical composition including the anti-PCSK9 antibody and antigen-binding fragment thereof and one or more pharmaceutically acceptable carriers. Pharmaceutically acceptable carriers for use in the pharmaceutical compositions disclosed herein may include, for example, pharmaceutically acceptable liquid, gel or solid carriers, aqueous media, non-aqueous media, antimicrobial substances, etc. Osmotic substances, buffers, antioxidants, anesthetics, suspending agents / dispersants, chelating agents, diluents, adjuvants, excipients or non-toxic auxiliary substances, other components known in the art or a combination of the above. Suitable components may include, for example, antioxidants, fillers, binders, disintegrants, buffers, preservatives, lubricants, flavoring agents, thickeners, colorants, emulsifiers or stabilizers such as sugars and Cyclodextrin. Suitable antioxidants may include, for example, methionine, ascorbic acid, EDTA, sodium thiosulfate, platinum, catalase, citric acid, cysteine, mercaptoglycerol, mercaptoacetic acid, mercaptosorbitol, butyl methyl anise Ether, butylated hydroxytoluene and / or propyl gallate. As disclosed in the present invention, including one or more antioxidants such as methionine in a composition containing the antibody or antigen-binding fragment thereof disclosed in the present invention can reduce the oxidation of the antibody or antigen-binding fragment thereof. A reduction in oxidation prevents or reduces a decrease in binding affinity, thereby increasing antibody stability and extending shelf life. Therefore, in certain embodiments, the composition provided by the present invention contains one or more of said antibodies or antigen-binding fragments thereof and one or more antioxidants such as methionine. The present invention further provides methods for preventing the antibody or the antigen-binding fragment thereof from being oxidized and prolonged by mixing the antibody or the antigen-binding fragment thereof provided in the present invention with one or more antioxidants, such as methionine. Shelf life and / or increase its activity. Further, a pharmaceutically acceptable carrier may include, for example, an aqueous medium such as sodium chloride injection, Ringer's solution injection, isotonic glucose injection solution, sterile water injection solution, or glucose and lactate Ringer Injections, non-aqueous media such as: non-volatile oils of plant origin, cottonseed oil, corn oil, sesame oil, or peanut oil, antibacterial substances at bacterial or fungal inhibitory concentrations, isotonic agents such as sodium chloride or glucose, Buffers such as phosphate or citrate buffers, antioxidants such as sodium bisulfate, local anesthetics such as procaine hydrochloride, suspending and dispersing agents such as sodium carboxymethyl cellulose, hydroxypropyl Methylcellulose or polyvinylpyrrolidone, emulsifiers such as polysorbate 80 (Tween-80), chelating agents such as EDTA (ethylenediaminetetraacetic acid) or EGTA (ethylene glycol bis (2- (2- Amine ethyl ether) tetraacetic acid), ethanol, polyethylene glycol, propylene glycol, sodium hydroxide, hydrochloric acid, citric acid or lactic acid. The antibacterial agent as a carrier can be added to the pharmaceutical composition in a multiple dose container, which includes phenols or cresols, mercury preparations, benzyl alcohol, chlorobutanol, methyl and propyl parabens, Thimerosa, ammonium chlorobenzyl and chlorophenethyl ammonium. Suitable excipients may include, for example, water, salt, glucose, glycerol or ethanol. Suitable non-toxic auxiliary substances may include, for example, emulsifiers, pH buffers, stabilizers, solubilizers, or substances such as sodium acetate, sorbitan laurate, triethanolamine oleate, or cyclodextrin . The pharmaceutical composition may be a liquid solution, a suspension, an emulsion, a pill, a capsule, a lozenge, a sustained release preparation, or a powder. Oral formulations can include standard carriers such as pharmaceutical grades of mannitol, lactose, starch, magnesium stearate, polyvinylpyrrolidone, sodium saccharin, cellulose, magnesium carbonate, and the like. In certain embodiments, the pharmaceutical composition is prepared as an injectable composition. Injectable pharmaceutical compositions can be prepared in any conventional form, for example, liquid solvents, suspending agents, emulsifiers or solid forms suitable for producing liquid solvents, suspending agents or emulsifiers. Injectable preparations may include current sterile and / or pyrogen-free solutions, sterile dry solubles that are combined with the solvent prior to use, such as lyophilized powder, including subcutaneous tablets, sterile suspensions ready for injection, and Vehicle-bound sterile dry insoluble products, and sterile and / or pyrogen-free emulsions. The solvent can be an aqueous or non-aqueous phase. In certain embodiments, the unit-dose injectable preparation is packaged in an ampoule, a tube, or a syringe with a needle. It is known in the art that all preparations for injection should be sterile and pyrogen-free. In certain embodiments, a sterile lyophilized powder can be prepared by dissolving the antibody or antigen-binding fragment thereof disclosed in this application in a suitable solvent. The solvent may contain a powder or a reconstituted solution prepared from the powder, or other pharmacological components to improve the stability. Suitable excipients include, but are not limited to, water, glucose, sorbitol, fructose, corn syrup, xylitol, glycerol, glucose, sucrose, or other suitable substances. The solvent may contain a buffer, such as a citrate buffer, a sodium or potassium phosphate buffer, or other buffers known to those skilled in the art. In one embodiment, the pH of the buffer is neutral. The dissolution is followed by sterilization by filtration under standard conditions well known in the art, and then lyophilization to obtain the desired formulation. In one embodiment, the resulting solvent is aliquoted into a vial and lyophilized. Each vial can contain a single dose or multiple doses of the anti-PCSK9 antibody or antigen-binding fragment thereof or a combination thereof. The amount of filling in each vial can be slightly higher than that required for each dose or multiple doses (for example, a 10% overdose) to ensure accurate sampling and accurate administration. The lyophilized powder can be stored under appropriate conditions, such as in the range of about 4 ° C to room temperature. The lyophilized powder was reconstituted with water for injection to obtain a preparation for injection administration. In one embodiment, the lyophilized powder can be reconstituted in sterile pyrogen-free water or other suitable liquid carriers. The exact amount is determined by the chosen therapy and can be determined based on experience. Methods of treatment are also provided that include administering a therapeutically effective amount of an antibody or antigen-binding fragment thereof described herein to an individual in need thereof, thereby treating or preventing a condition or disorder associated with PCSK9. In another aspect, a method of treating a condition in an individual who would benefit from an up-regulated immune response is also provided, comprising administering to the individual in need thereof a therapeutically effective amount of an antibody or antigen-binding fragment thereof as described herein. The therapeutically effective dose of the antibody or antigen-binding fragment thereof provided in this application depends on a variety of factors known in the art, such as weight, age, past medical history, current treatment, subject's health condition and potential for cross-infection, allergy, hypersensitivity And side effects, as well as the route of administration and the extent of tumor development. Those skilled in the art (eg, a doctor or veterinarian) can reduce or increase the dose proportionally according to these or other conditions or requirements. In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein can be administered at a therapeutically effective dose of about 0.01 mg / kg to about 100 mg / kg (e.g., about 0.01 mg / kg, about 0.5 mg / kg kg, about 1 mg / kg, about 2 mg / kg, about 3 mg / kg, about 5 mg / kg, about 10 mg / kg, about 15 mg / kg, about 20 mg / kg, about 25 mg / kg, about 30 mg / kg, about 35 mg / kg, about 40 mg / kg, about 45 mg / kg, about 50 mg / kg, about 55 mg / kg, about 60 mg / kg, about 65 mg / kg, about 70 mg / kg, about 75 mg / kg, about 80 mg / kg, about 85 mg / kg, about 90 mg / kg, about 95 mg / kg, or about 100 mg / kg). In certain embodiments, the antibody or antigen-binding fragment thereof is administered at a dose of about 50 mg / kg or less, and in certain embodiments, the dose is administered at 10 mg / kg or less, 5 mg / kg or less, 3 mg / kg or less, 1 mg / kg or less, 0.5 mg / kg or less or 0.1 mg / kg or less. A particular dose can be administered at multiple intervals, such as once a day, twice a day or more, twice a month or more, once a week, once every two weeks, once every three weeks, once a month, or every two Once a month or more. In certain embodiments, the dosage administered may vary with the course of treatment. For example, in certain embodiments, the initial dose may be higher than the subsequent dose. In certain embodiments, the administered dose is adjusted during the course of treatment based on the response of the subject to be administered. The dosing schedule can be adjusted to achieve an optimal response (such as a therapeutic response). For example, a single dose may be administered or divided into multiple divided doses over a period of time. The antibodies and antigen-binding fragments disclosed in the present invention can be administered by known administration methods such as injection (e.g., subcutaneous injection, intraperitoneal injection, intravenous injection, including intravenous drip, intramuscular injection or intradermal injection). Injection) or non-injection (eg, oral, nasal, sublingual, rectal or topical). Method of Use This application further provides a method of using the anti-PCSK9 antibody or antigen-binding fragment thereof. In some embodiments, the application provides a method of treating a PCSK9-mediated condition or disorder in an individual, comprising administering a therapeutically effective amount of a PCSK9 antibody or antigen-binding fragment thereof described herein. In some embodiments, the individual is identified as having a disorder or condition that is likely to respond to a PCSK9 inhibitor. In certain embodiments, the individual is at risk of having or developing a disease or condition mediated by PCSK9 that exhibits one or more symptoms of the disease or condition, such as being overweight, Have elevated cholesterol levels, have a genetic mutation in a gene encoding LDL-R or APOB, or have a family history of such diseases or conditions. In certain embodiments, the individual is resistant or intolerant to another cholesterol-lowering agent (e.g., a statin) during treatment, and therefore the cholesterol level cannot be effectively reduced to an acceptable level during the treatment Level. In certain embodiments, the PCSK9-mediated diseases or conditions include infectious diseases such as severe cellulitis, gastroenteritis, sepsis, pneumonia, skin and soft tissue infections, pyelonephritis, viral infections, for example, type B Hepatitis, hepatitis C, herpes virus infection, Epstein-Barr virus, HIV, cytomegalovirus, herpes simplex virus type I, herpes simplex virus type 2, human papilloma virus, adenovirus, Kaposi's sarcoma-related Herpes virus epidemics, Torquetenovirus, JC virus or BK virus, or include inflammatory diseases such as Alzheimer's disease, ankylosing spondylitis, arthritis (osteoarthritis, rheumatoid arthritis (RA ), Psoriasis arthritis), asthma, atherosclerosis, Crohn's disease, colitis, dermatitis, diverticulitis, fibromyalgia, hepatitis, irritable bowel syndrome (IBS), systemic lupus erythematosus (SLE), Nephritis, Parkinson's disease, and ulcerative colitis. The presence and level of LDL-C in the target biological tissue may indicate whether the individual from which the biological sample is derived is likely to respond to a PCSK9 inhibitor. Various methods can be used to determine the presence or level of LDL-C in a biological sample to be tested from the individual. Cholesterol levels are measured in the United States using milligrams (mg) per deciliter (dL) of blood, while millimoles (mmol) per liter (L) of blood are used in Canada and many European countries. In some embodiments, the presence or level of LDL-C, total cholesterol or non-HDL-C in the biological sample to be tested indicates the likelihood of a response. The term "up-regulation" as used herein refers to the total cholesterol level detected in a test sample using the antibody or antigen-binding fragment thereof described in the application compared to the cholesterol level in a reference sample detected with the same antibody Increase not less than 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80% or more many. The reference sample may be a control sample obtained from a healthy or disease-free individual, or a healthy or disease-free sample obtained from an individual from which the sample to be tested is derived. The antibodies and antigen-binding fragments disclosed herein can be administered alone or in combination with one or more other treatments or substances. For example, the antibodies and antigen-binding fragments disclosed in the present invention can interact with statins, HMG-CoA reductase inhibitors other than statins, nicotinic acid (nicotinic acid), cholesterol absorption inhibitors, cholesterol ester transfer protein (CETP), bile Acid chelators, fibrates, phytosterols; or regulators selected from small molecule lipid / lipid concentration ratios, peptidomimetics, antisense RNA, small interfering RNA (siRNA), and natural or modified lipids. In some embodiments, the cholesterol absorption inhibitor is ezetimibe or SCH-48461; the CETP is evacetrapib, anacetrapib or dalcetrapib; the bile acid sequestrant is preferably colesevelam, cholestyramine or fibrate Ning is preferably fenofibrate, gemfibrozil, antrum, or benzabate; or a combination of the above agents. In certain such embodiments, when the antibodies and antigen-binding fragments disclosed herein are used in combination with one or more of the above-mentioned therapeutic substances, they may be administered simultaneously with the one or more of the therapeutic substances. In some such embodiments, The antibody and the antigen-binding fragment can be administered simultaneously as part of the same pharmaceutical composition. However, antibodies and antigen conjugates that are "combined" with other therapeutic substances need not be administered simultaneously or in the same composition as the therapeutic substance. The meaning of "combined use" in the present invention also includes that an antibody and an antigen conjugate administered before or after another therapeutic substance are also considered to be "combined with" the therapeutic substance, even if the antibody or antigen-binding fragment thereof and the first The two substances are administered by different modes of administration. Where possible, other therapeutic substances used in combination with the antibodies or antigen-binding fragments thereof disclosed in the present invention can be used in accordance with the methods of the product description of the other therapeutic substances, or refer to the surgeon's desk reference book 2003 , 57th Edition; Medical Economics Company; ISBN: 1563634457; 57th Edition (November 2002)), or refer to other methods known in this technology. The following examples are intended to better illustrate the invention and should not be construed as limiting the scope of the invention. All the specific compositions, materials and methods described below, in whole or in part, are within the scope of the present invention. These specific compositions, materials, and methods are not intended to limit the invention, but merely to illustrate that specific embodiments are within the scope of the invention. Those skilled in the art can develop equivalent compositions, materials, and methods without adding creativity and without departing from the scope of the invention. It should be understood that various modifications made to the method of the present invention may still be included within the scope of the present invention. The inventor intends to include such variations within the scope of the present invention.Examples Examples 1 : Production of antigens and other proteins 1.1 Human and mouse PCSK9 The human and mouse PCSK9 genes were assembled into the pcDNA3.3 vector, respectively, and the 6-His tag or mouse Fc tag was fused to the C-terminus. These plasmids were transfected into HEK293 cells with transfection reagent PlasFect (Bioline USA, BIO-46026), respectively. The cell supernatant was collected after transfection. His tag protein was purified by Ni column (Qiagen Inc), and mouse Fc fusion protein was purified by Protein A column (MabSelect SuRe, GE). 1.2 Human LDL-R The LDL-R extracellular domain gene was assembled into the pcDNA3.3 vector, and the 6-His tag was fused to the C-terminus. These plasmids were transfected into HEK293 cells with a transfection reagent PlasFect (Bioline USA, BIO-46026). After transfection, the cell supernatant was collected. The LDL-R protein was purified in the first step using a Ni column (Qiagen Inc) and in the second step using an ion exchange column. 1.3 Reference antibody The sequence of the reference antibody BMK.115 is based on the 21B12 sequence in U.S. Patent No. 8,888,834B2. HEK293 cells were co-transfected with plasmids containing heavy and light chains. Cell supernatants were collected after transfection, and antibodies were purified by Protein A columns (MabSelect SuRe, GE).Examples 2 : Production of antibodies 2.1 Immunization Balb / c mice were injected with human-derived PCSK9 protein at the sole of the foot once every three days. After the 6 immunizations, the first titer test was performed, and then the immunization was performed once a week. 2.2 Serum titer detection The mouse serum titer was detected using an enzyme-linked immunosorbent assay (ELISA). First, the human PCSK9 protein was diluted to 1 μg / ml with a coating solution of pH 9.2, added to a microplate (Nunc), and incubated overnight at 4 ° C. After the plate was washed and closed, 200 μl of blocking solution 1 × PBS / 2% BSA was added to each well, and incubated at room temperature for 1 hour. A 100-fold dilution of mouse serum was added to the starting well, and then a serial gradient dilution of 3 times with the blocking solution was performed, followed by incubation at room temperature for 1 hour. After washing the plate, a goat anti-mouse IgG Fc HRP enzyme-labeled secondary antibody mixture (Bethyl) was added, and incubated at room temperature for 1 hour. After washing the plate, the TMB receptor color developing solution was added, and then the color development was stopped with 2M hydrochloric acid. The absorbance at 450 nM was read using a microplate reader (Molecular Device). 2.2.1 Animal immunity and hybridoma generation The titers of antigen-specific antibodies in the serum of immunized mice were detected by ELISA (Table 2). Mice with a titer of 656,100 were selected for fusion to produce hybridoma cells.table 2. Antibody titer in serum 2.3 Hybridoma cell fusion Select mice with titers that meet the requirements, remove the lymph nodes and spleen, and transfer them to a tissue mill for grinding. B cells were counted after filtering through a 100-mesh sieve. Myeloma SP2 / 0 cells were counted after adjusting the medium to an appropriate volume. Resuspend and mix the two cells according to the number of B cells: P3 = 1: 1. Cell suspensions were added to the fusion tank for electrofusion (BTX ECM2001). After fusion, transfer the cells to a medium containing 1/2 HA, 5 × 10 per plate⁵ Cell density plated. 2.4 Hybridoma screening ELISA to detect binding: first dilute streptavidin to 1 μg / ml with a coating solution of pH 9.2, add it to a 96-well microtiter plate (Nunc), and incubate overnight at 4 ° C . After blocking and washing the plate, biotin-labeled human-derived PCSK9 protein was added at a concentration of 250 ng / ml, and incubated at room temperature for 1 hour. After washing the plate, the hybridoma cell supernatant was added, and the cells were incubated at room temperature for 1 hour. After washing the plate, a goat anti-mouse IgG Fc HRP enzyme-labeled secondary antibody (Bethyl) mixture was added and incubated for 1 hour at room temperature. After washing the plate, the TMB substrate was added, and the color development was stopped with 2M hydrochloric acid, and then the absorbance at 450 nm was read using a microplate reader (Molecular Device). Competitive ELISA: LDL-R was added to the microtiter plate (Nunc) and incubated overnight at 4 ° C. At the same time, the supernatant of hybridoma cells was mixed with biotin-labeled human PCSK9 protein. The final concentration of PCSK9 protein was 250 ng / ml, and the cells were incubated overnight at 4 ° C. After the plate was washed and blocked, the mixture of the hybridoma cell supernatant and the PCSK9 protein was added, and the mixture was incubated at room temperature for 1 hour. After washing the plate, HRP-labeled streptavidin was added. Finally, the TMB receptor color development solution was added, and the color development was stopped with 2 M hydrochloric acid, and then the absorbance at 450 nm was read using a microplate reader (Molecular Device). Antibody screening In the first round of screening, the hybridoma culture supernatant was used to detect antigen binding, and 1090 hybridomas that specifically bound to the antigen were obtained. These hybridoma cell lines were screened for further competitive experiments. 54 hybridoma cells were screened by competitive ELISA, and the secreted antibodies could block the binding of human-derived PCSK9 to human-derived LDL-R. Seventeen hybridoma cell lines were selected for sub-selection. The selected subpure lines were detected by binding and competition ELISA, and their subtypes were identified. The purified antibody was further confirmed for its binding and blocking activity by ELISA (Figures 1 and 2). The IC50 results of the combined EC50 and blocking experiments are shown in Table 3. Table 3. Binding and blocking activities of antibodies 2.5 Sub-colonization of hybridoma cells The selected hybridoma cell lines were plated into 96-well plates at a density of 0.5, 1 and 5 cells per well. Individual wells were selected for detection by ELISA. Each hybridoma cell line was retained and cryopreserved 3 times. 2.6 Detection of antibody subtypes Antibody subtypes were detected by ELISA. Goat anti-mouse mouse IgG1, IgG2a, IgG2b, IgG3, and IgM antibodies (Bethyl) were diluted to 1 μg / ml with coating solution, added to 96-well microtiter plates (Nunc), and incubated overnight at 4 ° C. After the plate was blocked, the hybridoma cell culture supernatant was added, and the plate was allowed to stand at room temperature for 1 hour. After washing the plate, add goat anti-mouse Kappa chain enzyme-labeled secondary antibody (Southern Biotech) or goat anti-mouse Lambda chain enzyme-labeled secondary antibody (Southern Biotech), and incubate at room temperature for 45 minutes. After washing the plate, a TMB receptor color developing solution was added, and the color development was stopped with 2M hydrochloric acid, and then the absorbance at 450 nm was read using a microplate reader (Molecular Device). 2.7 Antibody purification After the collected hybridoma supernatant was adjusted to pH 7.0, it was loaded onto a Protein A column (MabSelect SuRe, GE). The antibodies were eluted with Glycine and immediately neutralized with 1M Tris. The purified protein concentration was detected by Nano Drop (Thermal-Fisher). The purity of the protein was detected by SDS-PAGE (Invitrogen, NuPAGE 4% -12% Bis-Tris Gel) and HPLC-SEC (Agilent).Examples 3 : Candidate Antibody Characterization 3.1 LDL absorption experiment: HepG2 or Huh-7 cells were treated with 10% FBS in DMEM at 1 × 10 per well.⁵ The density was inoculated into a 96-well plate and placed in a 37 ° C incubator. The next day, the DMEM medium containing 10% FBS was replaced with a serum-free medium, and wild-type PCSK9 or variant PCSK9 (D374Y) was mixed with a series of concentration-diluted antibodies and added to the corresponding wells, and incubated at 37 ° C. 1 hour. The final concentration of wild-type PCSK9 was 20 μg / ml. Bodipy fluorescently labeled LDL (Invitrogen L-3483) was added to a 96-well plate to a final concentration of 1.5 μg / ml. After incubating in a 37 ° C incubator for 3 hours, the 96-well plate was taken out, the culture medium containing LDL was discarded, and the cells were collected by trypsinization and washed twice. The intracellular fluorescence was detected by FACS, and the intensity of the fluorescence was indicative of the amount of LDL absorbed. The recovery rate of LDL absorption is calculated by the following formula: LDL absorption recovery rate (%) = (MFI_sample -MFI_{LDL + WBP301.Ag1H} ) / (MFI_{LDL-MFILDL + WBP301.Ag1H} ) × 100%. Candidate antibody characterization experiments Perform further characterization experiments on selected subpure lines, including cell LDL absorption experiments, kinetic affinity, species cross-reaction experiments, and antigen-binding epitope grouping experiments. The final candidate pure line was selected based on affinity, ability to block PCSK9 from binding to LDL-R, and ability to restore cellular LDL absorption. LDL absorption experiment: Detection of the antibody to restore the LDL absorption capacity of cells on HepG2 cells (see Figure 3), IC50 values are shown in Table 4. Some antibodies have IC50 values of tens of picomoles. The experimental results show that the detected candidate antibodies can effectively restore the absorption of LDL by cells.table 4. LDL Absorption experiment IC50 3.2 Detection of binding kinetic constants using SPR technology Biacore T200 (GE) was used to detect the binding affinity constants of antibodies to human PCSK9 and rhesus PCSK9. Replenish the antibody to be tested using Protein A or anti-IgG Fc antibody-conjugated chips. Then, different concentrations of human-derived PCSK9 or rhesus PCSK9 were injected into the sensor chip, and the injection speed was 30 ul / min. The sample binding time was 180 s and the dissociation time was 1200 s. After each antigen binding, use 2 M MgCl₂ Regeneration chip. The final binding dissociation curve is the result of subtracting the reference channel Fc1 and the buffer channel signals. The experimental data were fitted using a 1: 1 Langmiur model. The molecular weight used in the calculation of PCSK9 Molar was 85 KDa. Kinetic Affinity: The kinetic constant of antibody binding to human PCSK9 was detected by SPR experiment. Binding rate, dissociation rate and affinity constant (k_on , k_off And K_D ) See Table 5. Some candidate antibodies have an affinity for PCSK9 reaching nanomoles or tens of picomoles. Table 5. Kinetic constants of antibody binding to human PCSK9 3.3 Cross-reactivity with rhesus PCSK9 protein The mouse anti-His tag antibody (Genscript) was diluted to 1 μg / ml with a coating solution of pH 9.2, added to a 96-well microtiter plate, and incubated overnight at 4 ° C. After the plate was blocked, the Rhesus PCSK9-His (Sino Biological) protein was added at a concentration of 1 μg / ml and incubated for 1 hour at room temperature. After washing the plate, add the test antibody and incubate for 1 hour at room temperature. After washing the plate, add goat anti-mouse IgG Fc HRP enzyme-labeled secondary antibody (Bethyl) and incubate at room temperature for 45 minutes. Finally, the TMB receptor color development solution was added, and the color development was stopped with 2M hydrochloric acid after the reaction, and then the absorbance at 450 nm was read using a microplate reader (Molecular Device). Binding of monkey-derived PCSK9: The affinity of the candidate antibody for binding to rhesus PCSK9 was detected by ELISA (Figure 4). The results are shown in Table 6. Table 6. Affinity of antibodies binding to rhesus PCSK9 Examples 4 : Humanization of antibodies and antibody engineering 4.1 Sequencing of hybridomas. Trizol kit (Invitrogen-15596018) was used to extract RNA from hybridoma cells, and the 5'-RACE kit (Takara-28001488) was used to amplify cDNA. Then 3'-degenerate primers and 3 The '-linker primer (ExTaq: Takara-RR001B) amplified cDNA. The amplified fragment was inserted into a pMD18-T vector (Takara-D101C) and sent for sequencing (Shanghai Boshang). The selected antibodies 2.6.6 and 2.12.12.4 and their humanized antibody variable region sequences (amino acid sequences and nucleic acid sequences) are shown in SEQ ID NOs: 36-51. 4.2 Production of recombinant chimeric antibodies The gene sequence of each mouse antibody variable region was cloned into a pcDNA3.3 vector pcDNA3 containing human constant region genes. The heavy and light chain plasmids were transfected into HEK293 cells for antibody expression. The cell supernatant was collected by centrifugation. The antibodies were purified using Protein A (MabSelect SuRe, GE), and the purified antibodies were dialyzed into PBS. Antibody concentration was by Nanodrop. The purity of the protein was detected by SDS-PAGE (Invitrogen, NuPAGE 4% -12% Bis-Tris Gel) and HPLC-SEC (Agilent). 4.3 Humanization The heavy and light chains of the antibody were humanized by the "best match method". By comparing the light chain amino acid sequence of the corresponding V gene with the human V gene database. The sequence of the humanized light chain variable region gene is to replace the human CDR sequence with a mouse CDR sequence using the Kabat CDR definition. The same method was used to obtain 4 humanized heavy chain sequences. The first is the original light chain, and the remaining three are compared in the human V gene database using the mouse FR region. The FR region is defined by an extended CDR. Kabat CDR1 is a five amino acid extension at its nitrogen terminus. The top three scored sequences were used as the sequences of the humanized heavy chain genes. Humanized genes were synthesized by GeneArt Costum Gene Synthesis (Life Technologies), back-translated, and codon optimized for eukaryotic cell performance. The optimized gene sequence was synthesized and cloned into an antibody expression vector for expression purification. Humanized antibodies were re-characterized, including binding and blocking experiments, cell LDL absorption experiments, and kinetic affinity detection. 4.3.1 Binding activity and blocking activity of humanized antibodies ELISA method to verify the binding activity of humanized antibodies to PCSK9 and the activity of blocking the binding of PCSK9 to LDLR are shown in Figures 5 and 6. The experimental results showed that the binding activity and blocking activity of the humanized antibody 2.12.12.4-z4-uIgG4k was comparable to that of the original mouse antibody. The IC50 results of the combined EC50 and blocking experiments are shown in Table 7. And the humanized antibody 2.12.12.4-z4-uIgG4k showed comparable binding and blocking activity to the reference antibody Repatha (evolocumab). Table 7 • Humanized antibody binding and blocking activities 4.3.2 Kinetic affinity of humanized antibodies The kinetic binding constants of humanized antibodies 2.12.12.4-z4-uIgG4k and 2.6.6-z4-uIgG1k were detected by SPR experiments. The affinity of antibody binding to human PCSK9 and monkey PCSK9 is shown in Table 8. Table 8. Kinetic constants of antibody binding to human PCSK9 and monkey PCSK9 4.3.3 Humanized antibody LDL absorption experiment In the presence of wild-type PCSK9, the humanized 2.12.12.4 antibody was tested for LDL absorption activity on HepG2 and Huh-7 cells (Figure 7). IC50 values are shown in the table. 9. The results showed that humanized 2.12.12.4 was comparable to Repatha's ability to restore cellular LDL uptake. Table 9. Cellular LDL uptake experiments with humanized antibodies 4.3.4 Stability of humanized antibody in serum The test antibody was diluted with freshly separated human serum (serum content> 95%), and then incubated in a 37 ° C incubator for 0, 1, 3, 7, and 14 respectively. day. At the end of each time, after removing the sample from the 37 ° C incubator, it was quickly frozen in an ethanol-dry ice bath and the sample was stored in a -80 ° C refrigerator. Remove the sample and dissolve it quickly before the stability test. 96-well microtiter plate with Na₂ CO₃ / NaHCO₃ (pH 9.2) coated with streptavidin diluted in buffer, and placed in a refrigerator at 4 ° C. The next day, 96-well plates were washed with 0.1% PBST and blocked with 2% BSA / PBS for 1 hour before adding biotin-labeled PCSK9. After 1 hour incubation at room temperature, the samples were washed and a series of concentration-diluted samples were added. After 1 hour incubation at room temperature, washing was performed, and HRP-labeled goat anti-human IgG antibody was added. Incubate at room temperature for 1 hour, wash, add TMB substrate, and stop with 2M HCl after color development. The absorbance at a wavelength of 450 nm was read with a microplate reader (Molecular Device). After the antibodies were incubated in 37 ° C human serum, the activity of binding to PCSK9 was detected by ELISA (see Figure 8). After the humanized antibody 2.12.12.4-z4-uIgG4k was incubated in serum for 3 days, the binding activity was the same as that of the unincubated antibody. This indicates that the antibody can be stably present in the serum for at least 3 days. 4.3.5 Antibody modification In order to enhance antibody stability, the sequence of humanized antibody 2.12.12.4-z4-uIgG4k was further improved (). Two amino acids in the variable region were mutated (as shown in 2.12.12.4-v2-z4-uIgG4k), and the mutated antibody sequence is shown in SED ID NO: 44-47. SPR experiments were used to detect the affinity of the modified antibody for binding to PCSK9. The kinetic data (Table 10) shows that the modified antibody 2.12.12.4-v2-z4-ulgG4k (D30E, N85D) has comparable affinity to the original antibody. Table 10. SPR data of mutant antibodies 4.3.6 Transient expression of humanized antibodies Humanized antibodies 2.12.12.4-z4-uIgG4k are characterized by SDS-PAGE under reducing conditions with molecular weights of 25 kDa and 55 kDa, corresponding to the light and heavy chains of the antibody ( (See Figure 9). The main band on non-reducing SDS-PAGE corresponds to a complete IgG molecule with a molecular weight of approximately 150 KD. HPLC-SEC results showed 100% antibody purity (see Figure 10). Endotoxin content is less than 0.5 EU / mg.Examples 5 :Animal experiment Four female cynomolgus monkeys aged 3-4, weighing between 2.5 and 3.5 kg, were randomly divided into 4 groups (1 in each group). Four groups of monkeys received a single intravenous injection of either 3 mg / kg or 10 mg / kg of Repatha or 2.12.12.4-z4-uIgG4K (unengineered) antibody. The day of dosing was defined as the first day. The monkeys in each group were observed for 36 days after administration. 5.1 Effect of a single injection in cynomolgus monkeys Using LDLC and HDLC3 kits (Roche) to detect low density lipoprotein cholesterol LDL-C and high density lipoprotein cholesterol HDL-C in monkey serum on the Roche / Hitachi cobas c system concentration. Total cholesterol TCHO was detected with cholesterol FS kit (DiaSys). The effect of antibody 2.12.12.4-z4-uIgG4k in reducing low-density cholesterol in cynomolgus monkeys. After cynomolgus monkeys were dosed at 3 mg / kg and 10 mg / kg, respectively, the antibodies Repetha and 2.12.12.4-z4-uIgG4k could quickly and persistently lower the levels of low-density lipoprotein cholesterol and total cholesterol (see Figure 11). . In monkeys administered with Repetha and 2.12.12.4-z4-uIgG4k antibodies, the HDL cholesterol level did not change significantly during the experiment, regardless of the 10 mg / kg or 30 mg / kg dose group (see Figure 12). In the 3 mg / kg and 10 mg / kg dose groups, Repatha reduced low-density cholesterol to 80% and 75%, respectively, compared to before administration; 2.12.12.4-z4-uIgG4k decreased in both dose groups. LDL cholesterol is reduced to 65%. The maximum reduction is reached on days 8-16. Therefore, compared with Repatha, 2.12.12.4-z4-uIgG4k can maintain low-density lipoprotein at a lower level in both the 3 mg / kg and 10 mg / kg dose groups for a longer time. 5.2 Pharmacokinetics The level of drug exposure in the body was obtained by measuring Repatha and 2.12.12.4 concentrations in animal serum. Blood samples were collected from all surviving cynomolgus monkeys for 0 hours (before dosing), and 0.5, 1, 2, 4, 24, 48, 96, 168, 336, 504, 672, 744, and 840 hours after dosing. Approximately 2 mL of whole blood was collected from the cephalic or femoral veins of the animal and placed in an anticoagulant-free blood collection tube. Allow blood samples to stand at room temperature for at least 30 minutes after collection. Centrifuge at 2000 g for 10 minutes at approximately 4 ° C to obtain serum (completed within 2 hours after blood sample collection). The serum was transferred to a labeled polypropylene sample tube. Immediately put it into dry ice and freeze it vertically, then store it in an ultra-low temperature refrigerator ≤-60 °. Thaw serum samples quickly before pharmacokinetic detection. With Na₂ CO₃ / NaHCO₃ After the goat anti-human polyclonal antibodies were diluted with the buffer solution, the enzyme-labeled detection plate was coated and incubated overnight at 4 ° C. After washing the plate with 0.1% Tween-PBS, block with 2% BSA / PBS. The diluted cynomolgus monkey serum samples were added to the microtiter plate and incubated for one hour at room temperature. After washing the plates, biotin-labeled goat anti-human IgG antibody and streptavidin-HRP were added to the enzyme-labeled plates, and incubated at room temperature for one hour. TMB was added to the substrate and it was stopped with 2M HCl after color development. The absorbance of each well was read at a wavelength of 450 nm. The antibody concentration in the serum was calculated from the standard curve. Pharmacokinetic parameters include, but are not limited to, initial serum concentrations (C₀ ) And the area under the blood concentration-time curve (AUC) from 0 hours to 840 hours after administration_0-840h ), Use the verified WinNonlin program (PharsightVersion 6.2.1) for calculation. Calculate AUC using the non-atrial method's linear ascending / logarithmic descending trapezoidal rule_0-840h , Limited to the animals treated. When calculating the average value, BLQ (below the quantitative value) is calculated as 0. The antibody concentration in the serum was detected by ELISA (Figure 13). Repatha and C of 2.12.12.4-z4-uIgG4k calculated from antibody concentration in serum from 0 to 840 hours₀ Value and AUC_{0 - 840h} See Table 11 for antibody half-life. The results showed that the half-life of antibody 2.12.12.4-z4-uIgG4k was longer than that of Repatha in both dose groups. When the dose was increased from 3 mg / kg to 10 mg / kg, the drug exposure levels of Repatha and 2.12.12.4-z4-uIgG4k (AUC_{0 - 840h} And / or C₀ ) Increase proportionally. Table 11. Pharmacokinetic data 5.3 Immunogenicity Blood samples were collected from the cephalic or femoral veins of animals at 0 hours (before administration) and 336, 672, and 840 hours after administration. With Na₂ CO₃ / NaHCO₃ The buffer was diluted with antibody Repatha or 2.12.12.4-z4-uIgG4K and plated (Nunc) and incubated overnight at 4 ° C. Plates were washed with 0.1% Tween-PBS and blocked with 2% BSA / PBS. PBS-diluted monkey serum was added to the microtiter plate and incubated for 1 hour at room temperature. After washing the plates, goat anti-cynomolgus IgG-HRP (without cross-reaction with human IgG) was added and incubated. After washing the plate, TMB was added to the substrate, and it was stopped with 2M HCl after color development. The absorbance of each well was read at a wavelength of 450 nm. The results of immunogenicity detection of antibody 2.12.12.4-z4-uIgG4k are shown in Figure 14. Antibodies (ADA) titers against 2.12.12.4-z4-uIgG4k in monkey sera at 336, 672, and 840 hours after administration were increased compared to before administration. 5.4 Toxicity Death / Near death: The health status of each animal is reported twice a day during the experiment, once in the morning and once in the afternoon, except when the animal arrives at the facility and the animal is checked on the day of dissection. Animals died unexpectedly throughout the experiment. Detailed clinical observation: All animals (including replacement animals) will be subjected to a detailed clinical observation before the experiment, and all experimental animals will be observed once on the administration day (about 2 ± 0.5 hours after administration). A detailed clinical observation was performed once a week. No drug-related clinical symptoms were observed throughout the experiment. Cage observation: In the early stage of the experiment, all animals (including replacement animals) were observed once a day from the cage 2 days before administration. It was performed once on the first day of the experiment, twice a day by the cage on the day of administration (within 30 minutes after administration and about 6 ± 0.5 hours after the administration), and once every day during the recovery period. Detailed clinical observations were scheduled at the same time period, and no cage observation was performed. Weight: Each animal was weighed once before the experiment. For experimental animals, the body was weighed once before administration on the first day of the experiment, and then weighed once a week during the experiment. No drug-related weight changes were observed, and all weight changes were within normal biological differences. Food intake: For all animals, the animal food intake was evaluated 2 days before the experimental administration and throughout the experimental administration and observation process. Daily food intake was assessed by monitoring the appetite of all animals (whether or not the animals constituted an assessment file). There were no drug-related changes in food intake. Although the present disclosure has been specifically shown and described with reference to specific embodiments (some of which are preferred embodiments), those skilled in the art should understand that, as shown in this application, the present invention may be implemented without departing from the spirit and scope of the present invention Inside, various changes in form and detail can be made.

Figures 1A-1C show the detection of candidate anti-PCSK9 hybridoma secondary colony antibodies by human ELISA with PCSK9. 2A-2C show an ELISA experiment in which a candidate anti-PCSK9 hybridoma secondary colony antibody blocks the binding of PCSK9 to the LDL receptor (LDL-R). Figures 3A-3B show the results of experiments on the recovery of LDL uptake by candidate pure line PCSK9 antibodies in hepatocellular carcinoma (HepG2) cells. FIG. 4 shows the results of binding assays of candidate antibodies to rhesus PCSK9 binding ELISA. Figure 5 shows an ELISA experiment in which the humanized antibody 2.12.12.4-z4-uIgG4k and Repatha (also known as evolocumab) bind to human PCSK9. Figure 6 shows that the humanized antibody 2.12.12.4-z4-uIgG4k and Repatha blocked PCSK9 and LDL-R binding ELISA experiments. Figures 7A-7B show experiments to restore LDL uptake by humanized antibodies 2.12.12.4-z1-IgG4K, 2.12.12.4-z2-IgG4K, and Repatha in cells HepG2 and Huh-7. Figure 8 shows the stability in serum of humanized antibodies 2.12.12.4-z4-uIgG4k and BMK.115 indicated by concentration as determined by ELISA method binding. Figure 9 shows the staining results of humanized antibody 2.12.12.4-z4-uIgG4k in SDS-PAGE gel. M: protein molecular weight marker; Lane1: 2.12.12.4-z4-uIgG4k, reducing conditions; Lane2: 2.12.12.4-z4-uIgG4k, non-reducing conditions. Figure 10 shows the HPLC-SEC spectrum of 2.12.12.4-z4-uIgG4k as 100% pure. Figure 11 shows the percentage change of cynomolgus monkey low density lipoprotein (LDL-C) after administration of antibody (2.12.12.4-z4-uIgG4k or Repatha). FIG. 11A shows the result of a single injection of 3 mg / kg, and FIG. 11B shows the result of a single injection of 10 mg / kg. Figure 12 shows the percentage change of cynomolgus monkey high density lipoprotein (HDL-C) after administration of antibody (2.12.12.4-z4-uIgG4k or Repatha). FIG. 12A shows the result of a single injection of 3 mg / kg, and FIG. 12B shows the result of a single injection of 10 mg / kg. Figure 13 shows the concentrations of antibodies 2.12.12.4-z4-uIgG4k or Repatha before and after administration in cynomolgus monkey serum measured by ELISA method. FIG. 13A shows the result of a single injection of 3 mg / kg, and FIG. 13B shows the result of a single injection of 10 mg / kg. Figure 14 shows titers of anti-antibody (ADA) against 2.12.12.4-z4-uIgG4k in cynomolgus monkey sera before and after administration. FIG. 14A shows the result of a single injection of 3 mg / kg, and FIG. 14B shows the result of a single injection of 10 mg / kg.

Claims (37)

An isolated antibody or antigen-binding fragment thereof comprising a heavy chain CDR sequence selected from the group consisting of SEQ ID NOs: 1, 3, 5, 13, 15, and 17. The antibody or antigen-binding fragment of claim 1, comprising a light chain CDR sequence selected from the group consisting of: SEQ ID NOs: 7, 9, 11, 19, 21, 23, and 25. The antibody or antigen-binding fragment thereof according to any one of the preceding claims, comprising a heavy chain variable region selected from the group consisting of: a) a heavy chain variable region comprising SEQ ID NO: 1, SEQ ID NO: 3 And / or SEQ ID NO: 5; and b) a heavy chain variable region comprising SEQ ID NO: 13, SEQ ID NO: 15 and / or SEQ ID NO: 17. The antibody or antigen-binding fragment thereof according to any one of the preceding claims, comprising a light chain variable region selected from: a) a light chain variable region comprising SEQ ID NO: 7, SEQ ID NO: 9 and / or SEQ ID NO: 11; b) a light chain variable region comprising SEQ ID NO: 19, SEQ ID NO: 21 and / or SEQ ID NO: 23; c) a variable light chain Region comprising SEQ ID NO: 25, SEQ ID NO: 21 and / or SEQ ID NO: 23. The antibody or antigen-binding fragment thereof according to any one of the preceding claims, comprising: a) a heavy chain variable region comprising SEQ ID NO: 1, SEQ ID NO: 3, and / or SEQ ID NO: 5; and A light chain variable region comprising SEQ ID NO: 7, SEQ ID NO: 9 and / or SEQ ID NO: 11; or b) a heavy chain variable region comprising SEQ ID NO: 13, SEQ ID NO: 15 And / or SEQ ID NO: 17; and a light chain variable region comprising SEQ ID NO: 19, SEQ ID NO: 21 and / or SEQ ID NO: 23; or c) a heavy chain variable region comprising SEQ ID NO: 13, SEQ ID NO: 15 and / or SEQ ID NO: 17; and a light chain variable region comprising SEQ ID NO: 25, SEQ ID NO: 21, and / or SEQ ID NO: 23. The antibody or antigen-binding fragment thereof according to any one of the preceding claims, comprising a heavy chain variable region selected from the group consisting of SEQ ID NO: 36, SEQ ID NO: 40, SEQ ID NO: 44, SEQ ID NO : 48 and homologous sequences with at least 80% sequence identity. The antibody or antigen-binding fragment thereof according to any one of the preceding claims, comprising a light chain variable region selected from the group consisting of SEQ ID NO: 38, SEQ ID NO: 42, SEQ ID NO: 46, SEQ ID NO : 50 and homologous sequences with at least 80% sequence identity. The antibody or antigen-binding fragment thereof according to any one of the preceding claims, comprising: a) a heavy chain variable region comprising SEQ ID NO: 36; and a light chain variable region comprising SEQ ID NO: 38; b) a heavy chain variable region including SEQ ID NO: 40; and a light chain variable region including SEQ ID NO: 42; c) a heavy chain variable region including SEQ ID NO: 44; and a light chain A variable region comprising SEQ ID NO: 46; d) a heavy chain variable region comprising SEQ ID NO: 48; and a light chain variable region comprising SEQ ID NO: 50; or e) and a), b), c) or d) a heavy chain variable region and a light chain variable region having at least 80% sequence identity. The antibody or antigen-binding fragment thereof according to any one of the preceding claims, which is capable of specifically binding to human PCSK9 with a KD value of no more than 10 ^-8 M, no more than 10 ^-9 M, or no more than 10 ^-10 M, The Kd value is measured by a surface plasmon resonance binding method or an ELISA method. The antibody or antigen-binding fragment thereof according to any one of the preceding claims, which binds to monkey PCSK9 with a KD value of not more than 10 ^-8 M or not more than 10 ^-9 M. The antibody or antigen-binding fragment thereof according to any one of the preceding claims, which is capable of blocking the binding of human PCSK9 to its ligand with an IC50 value of not more than 10 nM, not more than 5 nM, or not more than 3 nM. The antibody or antigen-binding fragment thereof according to any one of the preceding claims, which is capable of binding to human PCSK9 with an EC50 value of not more than 0.15 nM. The antibody or antigen-binding fragment thereof according to any one of the preceding claims, which is capable of restoring cellular LDL absorption with an IC50 value of not more than 140 nM, not more than 92 nM, or not more than 80 nM. The antibody or antigen-binding fragment thereof according to any one of the preceding claims, which is stable in serum for at least 3 days. The antibody or antigen-binding fragment thereof according to any one of the preceding claims, which does not mediate ADCC or CDC or neither. The antibody or antigen-binding fragment thereof according to any one of the preceding claims, which is a humanized monoclonal antibody. The antibody or antigen-binding fragment thereof of claim 16, wherein the humanized monoclonal antibody is produced by a host cell. The antibody or antigen-binding fragment thereof according to any one of the preceding claims, which is capable of reducing LDL cholesterol to 65% in animals. The antibody or antigen-binding fragment thereof according to any one of the preceding claims, which has a serum half-life of at least 110 hours or at least 195 hours. An antibody or antigen-binding fragment thereof that competes with the antibody or antigen-binding fragment of any one of the preceding claims for the same epitope. The antibody or antigen-binding fragment thereof according to any one of the preceding claims, which is a camelized single chain domain antibody, a diabody, scFv, scFv dimer, BsFv, dsFv, ( dsFv) 2, dsFv-dsFv ', Fv fragment, Fab, Fab', F (ab ') 2, ds diabody, nanobody, domain antibody or bivalent domain antibody. The antibody or antigen-binding fragment thereof according to any one of the preceding claims, further comprising an immunoglobulin constant region. The antibody or antigen-binding fragment thereof according to any one of the preceding claims, further comprising a conjugate. An isolated polynucleotide encoding the antibody or antigen-binding fragment thereof according to any one of claims 1 to 22. A vector comprising an isolated polynucleotide as claimed in claim 24. A host cell comprising a vector as claimed in claim 25. A method of expressing an antibody or an antigen-binding fragment thereof according to any one of claims 1 to 22, comprising culturing a host cell according to claim 27 under conditions expressing an isolated polynucleotide as described in claim 24. A kit comprising an antibody or antigen-binding fragment thereof according to any one of claims 1 to 22. A method of treating a condition associated with PD-1 in an individual, comprising administering to the individual a therapeutically effective amount of an antibody or antigen-binding fragment thereof according to any one of claims 1 to 22. The method of claim 29, wherein said individual is identified as having a disorder or condition that is likely to respond to a PCSK9 inhibitor. The method of claim 30, wherein said individual is identified as having an increased level of serum LDL cholesterol, total cholesterol, and / or non-HDL cholesterol in a test biological sample from said individual. A pharmaceutical composition comprising the antibody or antigen-binding fragment thereof according to any one of claims 1 to 23 and one or more pharmaceutically acceptable carriers. A method of treating a condition in an individual who would benefit from an up-regulated immune response, comprising administering to said individual a therapeutically effective amount of an antibody or antigen-binding fragment thereof according to any one of claims 1 to 23. The method of claim 29, wherein said individual has an elevated serum LDL cholesterol, total cholesterol, and / or non-HDL cholesterol levels. Use of an antibody or antigen-binding fragment thereof according to any one of claims 1 to 23 for the manufacture of a medicament for the treatment of a condition that would benefit from an up-regulated immune response. The use according to claim 35, wherein the conditions are cardiovascular disease, inflammatory disease and infectious disease. The use according to claim 36, wherein the infectious disease is sepsis.