Muscle-targeting complex and its use in the treatment of facioscapulohumeral muscular dystrophy

Abstract

Muscle-targeting complexes and their use in the treatment of facioscapulohumeral muscular dystrophy. Some aspects of this disclosure relate to complexes comprising a muscle-targeting agent covalently linked to a molecular load. In some embodiments, the muscle-targeting agent specifically binds to an internalized cell surface receptor on muscle cells. In some embodiments, the molecular load inhibits the expression or activity of DUX4. In some embodiments, the molecular load is an oligonucleotide, such as an antisense oligonucleotide or an RNAi oligonucleotide.

Description

[0001] This application is a divisional application of Chinese patent application No. 202180019466.4 entitled "Muscle-targeting complex and its use in treating facioscapulohumeral muscular dystrophy". The parent application is the application that entered the Chinese national phase of PCT international patent application PCT / US2021 / 012719 filed on January 8, 2021.

[0002] Related applications

[0003] This application claims the following filing-date interests under 35 USC § 119(e): U.S. Provisional Application No. 63 / 132,929, filed December 31, 2020, entitled “MUSCLE TARGETING COMPLEXES AND USES THEREOF”; U.S. Provisional Application No. 63 / 061,833, filed August 6, 2020, entitled “MUSCLE TARGETING COMPLEXES AND USES THEREOF FORTREATING FACIOSCAPULOHUMERAL MUSCULAR DYSTROPHY”; U.S. Provisional Application No. 63 / 055,513, filed July 23, 2020, entitled “MUSCLE TARGETING COMPLEXES AND USES THEREOF FORTREATING FACIOSCAPULOHUMERAL MUSCULAR DYSTROPHY”; and U.S. Provisional Application No. 63 / 055,513, filed January 31, 2020, entitled “MUSCLE…”. U.S. Provisional Application No. 62 / 968,761, entitled “MUSCLE TARGETING COMPLEXES AND USES THEREOF FORTREATING FACIOSCAPULOHUMERAL MUSCULAR DYSTROPHY”, filed January 24, 2020; and U.S. Provisional Application No. 62 / 965,740, entitled “MUSCLE TARGETING COMPLEXES AND USES THEREOF FORTREATING FACIOSCAPULOHUMERAL MUSCULAR DYSTROPHY”, filed January 10, 2020; the contents of each of these applications are incorporated herein by reference in their entirety. Technical Field

[0004] This application relates to targeted complexes for delivering molecular payloads (e.g., oligonucleotides) to cells and their uses, particularly for the treatment of diseases.

[0005] The reference is the sequence list submitted as a text file via EFS-Web.

[0006] This application contains a sequence list that has been submitted via EFS-Web in ASCII format and is incorporated herein by reference in its entirety. The ASCII copy created on January 8, 2021, is named D082470030WO00-SEQ-ZJG and has a size of 239 kilobytes. Background Technology

[0007] Muscular dystrophy (MD) is a group of diseases characterized by progressive weakness and loss of muscle mass. These diseases are caused by mutations in genes encoding proteins required to form healthy muscle tissue. Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant type of MD that primarily affects the muscles of the face, shoulder, and upper arm. Other symptoms of FSHD include abdominal weakness, retinal abnormalities, hearing loss, and joint pain and inflammation. FSHD is the most common of the nine types of MD that affect both adults and children, with a worldwide incidence of approximately 1 in 8,300. FSHD is caused by abnormal production of double homeobox 4 (DUX4), a protein of unknown function. The DUX4 gene, which encodes the DUX4 protein, is located in the D4Z4 repeat region on chromosome 4 and is normally expressed only during fetal development, after which it is repressed by hypermethylation of the D4Z4 repeat surrounding and compacting the DUX4 gene. Two types of FSHD, type 1 and type 2, have been described. Type 1 (accounting for approximately 95% of cases) is associated with the deletion of the D4Z4 repeat on chromosome 4. Unaffected individuals typically have more than 10 repeats arranged in the subtelomere region of chromosome 4, while the most common form of FSHD (FSHD1) is caused by array contraction of at least 10 repeats, associated with diversified expression of DUX4 in skeletal muscle and reduced epigenetic repression. Type 2 FSHD (accounting for approximately 5% of cases) is associated with mutations in the SMCHD1 gene on chromosome 18. There is currently no effective treatment for FSHD other than supportive care and treatment targeting the symptoms of the disease. Summary of the Invention

[0008] According to some aspects, this disclosure provides complexes that target muscle cells for delivering molecular payloads to those cells. In some embodiments, the complexes provided herein are particularly useful for delivering molecular payloads that inhibit the expression or activity of DUX4, for example, in subjects with or suspected of having facioscapulohumeral muscular dystrophy (FSHD). Thus, in some embodiments, the complexes provided herein comprise a muscle-targeting agent (e.g., a muscle-targeting antibody) that specifically binds to a receptor on the surface of muscle cells for delivering the molecular payload to the muscle cells. In some embodiments, the complex is taken up into the cell via receptor-mediated internalization, and the molecular payload can then be released to perform its function within the cell. For example, a complex engineered to deliver an oligonucleotide can release the oligonucleotide such that it inhibits DUX4 gene expression in muscle cells. In some embodiments, the oligonucleotide is released via endosomal cleavage of a covalent linker connecting the oligonucleotide of the complex and the muscle-targeting agent.

[0009] Some aspects of this disclosure provide complexes comprising an anti-transferrin receptor antibody covalently linked to a molecular payload configured to inhibit the expression or activity of dual homeobox 4 (DUX4). In some embodiments, the anti-TfR antibody comprises heavy chain complementarity-determining region 1 (CDR-H1), heavy chain complementarity-determining region 2 (CDR-H2), heavy chain complementarity-determining region 3 (CDR-H3), light chain complementarity-determining region 1 (CDR-L1), light chain complementarity-determining region 2 (CDR-L2), and light chain complementarity-determining region 3 (CDR-L3) of any anti-TfR antibody listed in Tables 2, 4, and 7.

[0010] In some embodiments, the antibody comprises: CDR-H1, CDR-H2, and CDR-H3 containing the heavy chain variable region (VH) of the amino acid sequence of SEQ ID NO: 15, and CDR-L1, CDR-L2, and CDR-L3 containing the light chain variable region (VL) of the amino acid sequence of SEQ ID NO: 16. In some embodiments, the antibody comprises: CDR-H1, CDR-H2, and CDR-H3 containing the VH of the amino acid sequence of SEQ ID NO: 204, and CDR-L1, CDR-L2, and CDR-L3 containing the VL of the amino acid sequence of SEQ ID NO: 205. In some embodiments, the antibody comprises: CDR-H1, CDR-H2, and CDR-H3 containing the VH of the amino acid sequence of SEQ ID NO: 7, and CDR-L1, CDR-L2, and CDR-L3 containing the VL of the amino acid sequence of SEQ ID NO: 8. In some embodiments, the antibody comprises: CDR-H1, CDR-H2 and CDR-H3 of VH containing the amino acid sequence of SEQ ID NO: 23, and CDR-L1, CDR-L2 and CDR-L3 of VL containing the amino acid sequence of SEQ ID NO: 24.

[0011] In some embodiments, the antibody comprises: CDR-H1 of SEQ ID NO: 155, CDR-H2 of SEQ ID NO: 156, CDR-H3 of SEQ ID NO: 157, CDR-L1 of SEQ ID NO: 158, CDR-L2 of SEQ ID NO: 159, and CDR-L3 of SEQ ID NO: 14. In some embodiments, the antibody comprises: CDR-H1 of SEQ ID NO: 194, CDR-H2 of SEQ ID NO: 195, CDR-H3 of SEQ ID NO: 196, CDR-L1 of SEQ ID NO: 197, CDR-L2 of SEQ ID NO: 198, and CDR-L3 of SEQ ID NO: 193. In some embodiments, the antibody comprises: CDR-H1 of SEQ ID NO: 145, CDR-H2 of SEQ ID NO: 146, SEQ ID NO: 267 or SEQ ID NO: 269, CDR-H3 of SEQ ID NO: 147, CDR-L1 of SEQ ID NO: 148, CDR-L2 of SEQ ID NO: 149 and CDR-L3 of SEQ ID NO: 6. In some embodiments, the antibody comprises: CDR-H1 of SEQ ID NO: 165, SEQ ID NO: 271 or SEQ ID NO: 273, CDR-H2 of SEQ ID NO: 166, CDR-H3 of SEQ ID NO: 167, CDR-L1 of SEQ ID NO: 168, CDR-L2 of SEQ ID NO: 169 and CDR-L3 of SEQ ID NO: 22.

[0012] In some embodiments, the antibody comprises having human or humanized frame regions of the following: CDR-H1, CDR-H2, CDR-H3 of VH shown in SEQ ID NO: 15 and CDR-L1, CDR-L2, CDR-L3 of VL shown in SEQ ID NO: 16. In some embodiments, the antibody comprises having human or humanized frame regions of the following: CDR-H1, CDR-H2, CDR-H3 of VH shown in SEQ ID NO: 204 and CDR-L1, CDR-L2, CDR-L3 of VL shown in SEQ ID NO: 205. In some embodiments, the antibody comprises having human or humanized frame regions of the following: CDR-H1, CDR-H2, CDR-H3 of VH shown in SEQ ID NO: 7 and CDR-L1, CDR-L2, CDR-L3 of VL shown in SEQ ID NO: 8. In some embodiments, the antibody comprises human or humanized frame regions having the following human frame regions: CDR-H1, CDR-H2, CDR-H3 of VH shown in SEQ ID NO: 23 and CDR-L1, CDR-L2, CDR-L3 of VL shown in SEQ ID NO: 24.

[0013] In some embodiments, the antibody comprises a VH containing an amino acid sequence having at least 80% identity with SEQ ID NO: 15, and a VL containing an amino acid sequence having at least 80% identity with SEQ ID NO: 16. In some embodiments, the antibody comprises a VH containing an amino acid sequence having at least 80% identity with SEQ ID NO: 204, and a VL containing an amino acid sequence having at least 80% identity with SEQ ID NO: 205. In some embodiments, the antibody comprises a VH containing the amino acid sequence of SEQ ID NO: 204 and a VL containing the amino acid sequence of SEQ ID NO: 205. In some embodiments, the antibody comprises a VH containing an amino acid sequence having at least 80% identity with SEQ ID NO: 7, and a VL containing an amino acid sequence having at least 80% identity with SEQ ID NO: 8. In some embodiments, the antibody comprises VH containing an amino acid sequence having at least 80% identity with SEQ ID NO: 23, and VL containing an amino acid sequence having at least 80% identity with SEQ ID NO: 24.

[0014] In some implementations, the equilibrium dissociation constant (K0) of the antibody binding to the transferrin receptor is... D ) is 10-11 M to 10 -6 M.

[0015] In some embodiments, the antibody is selected from full-length IgG, Fab fragment, F(ab') fragment, F(ab')2 fragment, scFv, and Fv. In some embodiments, the antibody is a Fab' fragment.

[0016] In some implementations, the molecular payload is an oligonucleotide.

[0017] In some embodiments, the oligonucleotide comprises an antisense strand of 18 to 30 nucleotides in length and includes a region complementary to at least 15 consecutive nucleotides of SEQ ID NO: 258 or 339, optionally wherein the antisense strand includes a region complementary to at least 15 consecutive nucleotides of SEQ ID NO: 261.

[0018] In some implementations, the oligonucleotide contains At least 15 consecutive nucleotides, wherein each T is optionally and independently U, wherein said oligonucleotides optionally contain The nucleotide sequence, wherein each T is optionally and independently U.

[0019] In some embodiments, the oligonucleotide comprises one or more phosphorodiamidate morpholinoligomers. In some embodiments, the oligonucleotide is a phosphorodiamidate morpholinoligomer (PMO).

[0020] In some implementations, the oligonucleotide also includes a sense strand that hybridizes with the antisense strand to form a double-stranded siRNA.

[0021] In some embodiments, the oligonucleotide comprises at least one modified nucleoside link. In some embodiments, the at least one modified nucleoside link is a phosphate thioester link.

[0022] In some implementations, the oligonucleotide comprises one or more modified nucleosides.

[0023] In some implementations, one or more modified nucleosides are 2' modified nucleosides.

[0024] In some embodiments, the 2' modified nucleotide is selected from: 2'-O-methyl (2'-O-Me), 2'-fluoro (2'-F), 2'-O-methoxyethyl (2'-MOE), and 2',4'-bicyclic nucleotide.

[0025] In some implementations, the 2',4'-bicyclic nucleotide is selected from locked nucleic acid (LNA), ethylene-bridged nucleic acid (ENA), and (S)-restricted ethyl-bridged nucleic acid (cEt).

[0026] In some embodiments, the muscle target is covalently linked to the molecular load via a cleavable linker. In some embodiments, the cleavable linker comprises a valine-citrulline dipeptide sequence.

[0027] In some embodiments, the muscle target is covalently linked to the molecular load via an inseverable connector. In some embodiments, the inseverable connector is an alkane connector.

[0028] In some implementations, the molecular payload is linked to the antibody by conjugation to lysine or cysteine ​​residues of the antibody.

[0029] This document also provides methods for inhibiting the expression or activity of DUX4 in cells. In some embodiments, the method includes contacting cells with a complex described herein that is effective in promoting the internalization of molecular loads into the cells.

[0030] Other aspects of this disclosure provide methods for treating subjects who have one or more deletions of the D4Z4 repeat associated with facioscapulohumeral muscular dystrophy (FSHD) on chromosome 4. In some embodiments, the method includes administering an effective amount of the complex described herein to the subject. Attached Figure Description

[0031] Figure 1 A non-restrictive schematic diagram is shown, illustrating the effect of transfecting cells with siRNA.

[0032] Figure 2 A non-limiting schematic diagram is depicted, illustrating the activity of a muscle-targeting complex containing siRNA.

[0033] Figures 3A to 3B A non-limiting schematic diagram is depicted, illustrating the activity of the muscle-targeting complex containing siRNA in mouse muscle tissue (gastrocnemius and heart) in vivo, relative to a control experiment. (N = 4 C57BL / 6 WT mice).

[0034] Figures 4A to 4E A non-limiting schematic diagram is depicted, illustrating the tissue selectivity of a muscle-targeting complex containing siRNA.

[0035] Figure 5A non-limiting schematic diagram is provided, illustrating the expression levels of DUX4 in three cell lines expressing DUX4 (A549, U-2 OS, and HepG2) and immortalized skeletal myoblasts (SkMC).

[0036] Figure 6 A non-restrictive schematic diagram is depicted, illustrating the ability of the phosphodiamidomorpholino oligomer (PMO) form (FM10 PMO) of the antisense oligonucleotide targeting DUX4 to reduce the expression levels of downstream DUX4 genes (ZSCAN1, MBD3L2, TRIM43).

[0037] Figure 7 A non-limiting schematic diagram is depicted, illustrating the ability of a muscle-targeting complex (anti-TfR-FM10) containing an anti-transferrin receptor antibody (15G11 antibody) and an FM10 antisense oligonucleotide to reduce the expression levels of downstream DUX4 genes (ZSCAN4, MBD3L2, TRIM43) in human U-2 OS cells relative to naked FM10 antisense oligonucleotides.

[0038] Figure 8 This is a graph showing the DMPK knockdown efficiency of conjugates in non-human primate (NHP) cells or cells from human DM1 patients (DM1), the conjugates comprising an anti-TfR1 antibody covalently conjugated to an antisense oligonucleotide targeting DMPK.

[0039] Figures 9A to 9B Different forms of anti-TfR1 antibodies were shown compared with human ( Figure 9A ) or cyno (crab-eating macaque) Figure 9B ( ) binding to transferrin receptor 1.

[0040] Figure 10 The binding of different anti-TfR1 antibody forms to human transferrin receptor 2 is shown. An anti-TfR2 monoclonal antibody (OTI1B1) was used as a control. None of the tested antibodies bound to TfR2.

[0041] Figure 11 This is a graph showing the DMPK knockdown efficiency of the conjugate in non-human primate (NHP) cells or cells derived from human DM1 patients (DM1), the conjugate comprising an anti-TfR1 antibody covalently conjugated herein to an antisense oligonucleotide targeting DMPK.

[0042] Figures 12A to 12B The binding of conjugated or unconjugated oligonucleotides to human TfR1 (hTfR1) and cynomolgus monkey TfR1 (cTfR1), as measured by ELISA, is shown. Anti-TfR is one of those listed in Table 7. Figure 12A The binding of anti-TfR alone (EC50 26.6 nM) or anti-TfR conjugated with an oligonucleotide targeting DMPK (EC50 8.2 nM) to hTfR1 was shown. Figure 12B The binding of cTfR1 to anti-TfR alone (EC50 33.6 nM) or anti-TfR conjugated with an oligonucleotide targeting DMPK (EC50 5.3 nM) is shown.

[0043] Figure 13 Quantitative cellular uptake of the anti-TfR Fab conjugate into rhabdomyosarcoma (RD) cells is shown. The molecular load in the test conjugate is an oligonucleotide targeting DMPK. Uptake of the conjugate is facilitated by the specified anti-TfR Fab. The assay also includes conjugates with either a negative control Fab (anti-mouse TfR) or a positive control Fab (anti-human TfR1). Cells were incubated with the specified conjugate at a concentration of 100 nM for 4 hours. Cellular uptake was measured by mean Cypher5e fluorescence. One of the anti-TfR antibodies is listed in Table 7.

[0044] Figure 14 The expression of DMPK in RD cells treated with different concentrations of conjugates containing an anti-TfR antibody (anti-TfR1 in Table 7) conjugated to an oligonucleotide targeting DMPK (control DMPK-ASO). Treatment lasted for 3 days. Control DMPK-ASO delivered using a transfection agent was used as a control.

[0045] Figure 15 The serum stability of the linker for connecting anti-TfR antibodies to molecular payloads (e.g., oligonucleotides) over time after intravenous administration in multiple species is shown.

[0046] Figures 16A to 16B This demonstrates the use of bare FM-10 ( ) within a certain concentration range. Figure 16A ) or FM-10 conjugated with anti-TfR1 ( Figure 16B Expression of MBD3L2, TRIM43 and ZSCAN4 transcripts in myotubes from FSHD patients treated with [the study].

[0047] Figures 17A to 17L A non-limiting schematic diagram is depicted, illustrating the ability of the muscle-targeting complex (DTX-C-012) containing an anti-transferrin receptor antibody (15G11 antibody) to reduce gene expression levels in muscle tissue of cynomolgus monkeys relative to the load assay and compared to naked ASO (control DMPK-ASO). (N=3 male cynomolgus monkeys). Figures 18A to 18BA non-limiting schematic diagram is depicted, illustrating the ability of the muscle-targeting complex (DTX-C-012) containing an anti-transferrin receptor antibody (15G11 antibody) to reduce gene expression levels in smooth muscle tissue of cynomolgus monkeys relative to the load assay and compared to naked ASO (control DMPK-ASO). (N=3 male cynomolgus monkeys).

[0048] Figures 19A to 19D A non-restrictive schematic diagram is provided, illustrating the tissue selectivity of the muscle-targeting complex (DTX-C-012) containing an anti-transferrin receptor antibody (15G11 antibody). The muscle-targeting complex did not reduce gene expression levels in liver, kidney, brain, or spleen tissues of cynomolgus monkeys compared to load assays (N=3 male cynomolgus monkeys).

[0049] Figure 20 Normalized mRNA tissue expression levels were shown across several tissue types in cynomolgus monkeys (N=3 male cynomolgus monkeys).

[0050] Figure 21 A single dose of the muscle-targeting complex (DTX-C-012) containing an anti-transferrin receptor antibody (15G11 antibody) was shown to be safe and well-tolerated in cynomolgus monkeys (N=3 male cynomolgus monkeys). Detailed Implementation

[0051] Some aspects of this disclosure relate to the understanding that while certain molecular payloads (e.g., oligonucleotides, peptides, small molecules) may have beneficial effects in muscle cells, effectively targeting such cells has proven challenging. As described herein, this disclosure provides complexes comprising a muscle target covalently linked to a molecular payload to overcome this challenge. In some embodiments, the complexes are particularly useful for delivering molecular payloads that inhibit the expression or activity of target genes in muscle cells, for example, in subjects who have or are suspected of having a rare muscle disease. For example, in some embodiments, a complex is provided for targeting DUX4 to treat subjects with FSHD. In some embodiments, the complexes provided herein contain oligonucleotides that inhibit DUX4 expression in subjects who have one or more D4Z4 duplicate deletions on chromosome 4. In some embodiments, the complexes provided herein comprise molecular payloads, such as guide molecules (e.g., guide RNA), capable of targeting a nucleic acid-programmable nuclease (e.g., Cas9) to the DUX4 gene to inactivate the gene in muscle cells, for example, by removing a portion of the DUX4 gene, or by introducing an inactivating mutation or a stop codon into the DUX4 gene. In some implementations, such a programmable nucleic acid nuclease can be used to inactivate DUX4, which is abnormally expressed in muscle cells.

[0052] Other aspects of this disclosure are provided below, including a description of the qualified terminology.

[0053] I. Definition

[0054] Application: As used herein, the term “application” means to deliver a complex to a subject in a physiologically and / or (e.g., and) pharmacologically available manner (e.g., to treat a condition in the subject).

[0055] Approximately: As used herein, the term “approximately” or “about”, when applied to one or more target values, refers to a value similar to the stated reference value. In some embodiments, the term “approximately” or “about” refers to a range of values ​​falling within (greater than or less than) 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, or less in any direction of the stated reference value, unless otherwise stated or otherwise apparent from the context (unless such a number exceeds 100% of the possible value).

[0056] Antibody: As used herein, the term "antibody" refers to a polypeptide comprising at least one immunoglobulin variable domain or at least one antigenic determinant (e.g., a paratope that specifically binds to an antigen). In some embodiments, the antibody is a full-length antibody. In some embodiments, the antibody is a chimeric antibody. In some embodiments, the antibody is a humanized antibody. However, in some embodiments, the antibody is a Fab fragment, an F(ab') fragment, an F(ab')2 fragment, an Fv fragment, or a scFv fragment. In some embodiments, the antibody is a nanobody derived from a camel antibody or a nanobody derived from a shark antibody. In some embodiments, the antibody is a biantibody. In some embodiments, the antibody comprises a framework having a human germline sequence. In another embodiment, the antibody comprises a heavy chain constant domain selected from IgG, IgG1, IgG2, IgG2A, IgG2B, IgG2C, IgG3, IgG4, IgA1, IgA2, IgD, IgM, and IgE constant domains. In some embodiments, the antibody comprises a heavy (H) chain variable region (hereinafter referred to as VH) and / or (e.g., and) a light (L) chain variable region (hereinafter referred to as VL). In some embodiments, the antibody comprises a constant domain, such as an Fc region. An immunoglobulin constant domain refers to a heavy chain or light chain constant domain. The amino acid sequences and functional variations of the human IgG heavy and light chain constant domains are known. Regarding the heavy chain, in some embodiments, the heavy chain of the antibody described herein may be an alpha (α), delta (Δ), epsilon (ε), gamma (γ), or mu (µ) heavy chain. In some embodiments, the heavy chain of the antibody described herein may comprise a human alpha (α), delta (Δ), epsilon (ε), gamma (γ), or mu (µ) heavy chain. In one specific embodiment, the antibody described herein comprises human γ1 CH1, CH2, and / or (e.g., and) CH3 domains. In some embodiments, the amino acid sequence of the VH domain comprises the amino acid sequence of the human gamma (γ) heavy chain constant region, such as any known in the art. Non-limiting examples of human constant region sequences have been described in the art, for example, see U.S. Patent No. 5,693,780 and Kabat EA et al., (1991), ibid. In some embodiments, the VH domain comprises an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, or at least 99% identity with any variable chain constant region provided herein. In some embodiments, the antibody is modified, for example, by glycosylation, phosphorylation, SUMOylation, and / or (e.g., and) methylation. In some embodiments, the antibody is a glycosylated antibody conjugated to one or more sugar or carbohydrate molecules.In some embodiments, one or more sugar or carbohydrate molecules are conjugated to the antibody via N-glycosylation, O-glycosylation, C-glycosylation, glycosylphosphatidylinositylation (GPI anchoring attachment), and / or (e.g., and) phosphoglycosylation. In some embodiments, one or more sugar or carbohydrate molecules are monosaccharides, disaccharides, oligosaccharides, or polysaccharides. In some embodiments, one or more sugar or carbohydrate molecules are branched oligosaccharides or branched polysaccharides. In some embodiments, one or more sugar or carbohydrate molecules comprise mannose units, glucose units, N-acetylglucosamine units, N-acetylglucosamine units, galactose units, fucose units, or phospholipid units. In some embodiments, the antibody is a construct comprising a polypeptide containing one or more antigen-binding fragments of this disclosure linked to a linker polypeptide or an immunoglobulin constant domain. The linker polypeptide comprises two or more amino acid residues linked by peptide bonds and is used to link one or more antigen-binding moieties. Examples of adaptor peptides have been reported (see, for example, Holliger, P., et al. (1993) Proc. Natl. Acad. Sci. USA 90:6444-6448; Poljak, RJ, et al. (1994) Structure 2:1121-1123). Additionally, antibodies can be part of larger immunoadhesion molecules, which are formed through covalent or non-covalent association of antibodies or antibody portions with one or more other proteins or peptides. Some examples of such immunoadhesion molecules include the use of the streptavidin core region to prepare tetrameric scFv molecules (Kipriyanov, SM, et al. (1995) Human Antibodies and Hybridomas 6:93-101), and the use of cysteine ​​residues, labeled peptides, and C-terminal multihistidine tags to prepare divalent and biotinylated scFv molecules (Kipriyanov, SM, et al. (1994) Mol. Immunol. 31:1047-1058).

[0057] CDR: As used in this paper, the term "CDR" refers to the complementarity-determining region within the antibody variable sequence. There are three CDRs in each variable region of the heavy and light chains, referred to as CDR1, CDR2, and CDR3 for each variable region. The term "CDR group" as used in this paper refers to a group of three CDRs capable of binding the antigen that appear within a single variable region. The exact boundaries of these CDRs have been defined differently depending on the system. The system described by Kabat (Kabat et al., Sequences of Proteins of Immunological Interest (National Institutes of Health, Bethesda, Md. (1987) and (1991)) not only provides a definitive residue numbering system applicable to any variable region of an antibody, but also provides precise residue boundaries defining three CDRs. These CDRs may be referred to as Kabat CDRs. Sub-regions of a CDR may be designated as L1, L2, and L3 or H1, H2, and H3, where “L” and “H” designate the light and heavy chain regions, respectively. These regions may be referred to as Chothia CDRs, which have boundaries that overlap with Kabat CDRs. Padlan (FASEB J. 9:133-139 (1995)) and MacCallum (J Mol Biol 262(5):732-45 (1996)) have described other boundaries defining CDRs that overlap with Kabat CDRs. Other CDR boundary definitions may not strictly follow one of the systems described above, but still overlap with Kabat. CDR overlap, although it can be shortened or lengthened based on predictions or experimental findings that a particular residue or group of residues or even the entire CDR does not significantly affect antigen binding. Although the preferred embodiment uses CDRs defined by Kabat or Chothia, the methods used herein may utilize CDRs defined according to any of these systems.

[0058] CDR-grafted antibody: The term "CDR-grafted antibody" refers to an antibody that contains heavy and light chain variable region sequences from one species, but in which one or more CDR regions of VH and / or (e.g., and) VL are replaced by CDR sequences from another species, such as an antibody having mouse heavy and light chain variable regions and in which one or more mouse CDRs (e.g., CDR3) have been replaced by human CDR sequences.

[0059] Chimeric antibody: The term "chimeric antibody" refers to an antibody that contains heavy and light chain variable region sequences from one species and constant region sequences from another species, such as a mouse heavy and light chain variable region linked to a human constant region.

[0060] Complementarity: As used herein, the term “complementarity” refers to the ability to precisely pair between two nucleotides or groups of nucleotides. Specifically, complementarity is a term characterizing the degree to which hydrogen-bonded pairing results in binding between two nucleotides or groups of nucleotides. For example, if a base at a position of an oligonucleotide is able to hydrogen bond with a base at a corresponding position of a target nucleic acid (e.g., mRNA), the bases at that position are considered complementary to each other. Base pairing can include both canonical Watson-Crick base pairing and non-Watson-Crick base pairing (e.g., Wobble base pairing and Hoogsteen base pairing). For example, in some embodiments, for complementary base pairing, an adenosine base (A) is complementary to a thymidine base (T) or a uracil base (U), a cytosine base (C) is complementary to a guanosine base (G), and universal bases such as 3-nitropyrrole or 5-nitroindole can hybridize with any A, C, U, or T and are considered complementary. Inosine (I) is also considered a universal base in the art and is believed to be complementary to any A, C, U or T.

[0061] Conservative amino acid substitution: As used herein, “conservative amino acid substitution” refers to an amino acid substitution that does not alter the relative charge or size characteristics of the protein to which the substitution is made. Variants can be prepared according to methods known to those skilled in the art for altering polypeptide sequences, methods which can be found, for example, in compilations of such methods: Molecular Cloning: A Laboratory Manual, J. Sambrook, et al., eds., Fourth Edition, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York, 2012, or Current Protocols in Molecular Biology, FM Ausubel, et al., eds., John Wiley & Sons, Inc., New York. Conservative amino acid substitutions include substitutions between amino acids within the following groups: (a) M, I, L, V; (b) F, Y, W; (c) K, R, H; (d) A, G; (e) S, T; (f) Q, N; and (g) E, D.

[0062] Covalent Linkage: As used herein, the term "covalent linkage" refers to the feature of two or more molecules being linked together by at least one covalent bond. In some embodiments, two molecules may be covalently linked together by a single bond, such as a disulfide bond or disulfide bridge, acting as a joint between the molecules. However, in some embodiments, two or more molecules may be covalently linked together by a molecule acting as a joint, which links the two or more molecules together by multiple covalent bonds. In some embodiments, the joint may be a cutterable joint. However, in some embodiments, the joint may be an incutterable joint.

[0063] Cross-reactivity: As used herein and in the case of a target agent (e.g., an antibody), the term "cross-reactivity" refers to the property of a substance to specifically bind with more than one antigen of similar type or class (e.g., multiple homologs, paralogs, or orthologs) with similar affinity or coercivity. For example, in some embodiments, antibodies that are cross-reactive to similar types or classes of human and non-human primate antigens (e.g., human transferrin receptor and non-human primate transferrin receptor) are capable of binding to human and non-human primate antigens with similar affinity or coercivity. In some embodiments, antibodies are cross-reactive to similar types or classes of human and rodent antigens. In some embodiments, antibodies are cross-reactive to similar types or classes of rodent and non-human primate antigens. In some embodiments, antibodies are cross-reactive to similar types or classes of human, non-human primate, and rodent antigens.

[0064] DUX4: As used herein, the term "DUX4" refers to the gene encoding a double homeobox 4 (DHS4), a protein typically expressed during fetal development and in the testes of adult males. In some embodiments, DUX4 may be a human gene (gene ID: 100288687), a non-human primate gene (e.g., gene ID: 750891, gene ID: 100405864), or a rodent gene (e.g., gene ID: 306226). In humans, DUX4 gene expression outside of fetal development and the testes is associated with facioscapulohumeral muscular dystrophy. Additionally, several human transcript variants encoding different protein isotypes have been characterized (e.g., as annotated with the following GenBank RefSeq accession numbers: NM_001293798.2, NM_001306068.2, NM_001363820.1).

[0065] Facial-scapular muscular dystrophy (FSHD): As used in this article, “facial-scapular muscular dystrophy (FSHD)” refers to a hereditary disorder caused by mutations in the DUX4 or SMCHD1 genes, characterized by reduced muscle mass and atrophy primarily in the muscles of the face, shoulder, and upper arm. Two types of this disease, type 1 and type 2, have been described. Type 1 is associated with a deletion in the D4Z4 repeat region containing the DUX4 gene on chromosome 4. Type 2 is associated with mutations in the SMCHD1 gene. Both type 1 and type 2 FSHD are characterized by abnormal production of the DUX4 protein outside the testes during fetal development. Facioscapulohumeral dystrophy, its genetic basis, and associated symptoms have been described in this field (see, for example, Campbell, AE, et al., “Facioscapulohumeral dystrophy: Activating an early embryonic transcriptional program in human skeletal muscle” Human Mol Genet. (2018); and Tawil, R. “Facioscapulohumeral muscular dystrophy” Handbook Clin. Neurol. (2018), 148: 541-548). Type 1 FSHD is associated with Online Mendelian Inheritance in Man (OMIM) Entry # 158900. Type 2 FSHD is associated with OMIM Entry # 158901.

[0066] Frame: As used herein, the term “frame” or “frame sequence” refers to the sequence remaining after subtracting the CDR from the variable region. Because the exact definition of a CDR sequence can be determined by different systems, the meaning of a frame sequence can be interpreted accordingly. The six CDRs (CDR-L1, CDR-L2, and CDR-L3 for the light chain and CDR-H1, CDR-H2, and CDR-H3 for the heavy chain) also distinguish frames on both the light and heavy chains into four sub-regions (FR1, FR2, FR3, and FR4) on each chain, where CDR1 lies between FR1 and FR2, CDR2 lies between FR2 and FR3, and CDR3 lies between FR3 and FR4. Where no specific sub-region is designated as FR1, FR2, FR3, or FR4, other references to frame regions refer to combinations of FRs within the variable region of a single naturally occurring immunoglobulin chain. As used herein, FR represents one of the four sub-regions, and FRs represent two or more of the four sub-regions constituting a frame region. Human heavy and light chain receptor sequences are known in the art. In one embodiment, a receptor sequence known in the art may be used in the antibody disclosed herein.

[0067] Human Antibody: As used herein, the term "human antibody" is intended to include antibodies having variable and constant regions derived from human germline immunoglobulin sequences. Human antibodies of this disclosure may contain amino acid residues not encoded by human germline immunoglobulin sequences (e.g., mutations introduced through random or site-specific mutagenesis in vitro or through somatic mutations in vivo), such as in CDRs, particularly CDR3. However, the term "human antibody" as used herein is not intended to include antibodies in which a CDR sequence derived from another mammalian species (e.g., mouse) has been grafted onto a human frame sequence.

[0068] Humanized Antibody: The term "humanized antibody" refers to an antibody containing heavy and light chain variable region sequences from a non-human species (e.g., mouse), but in which at least a portion of the VH and / or (e.g., and) VL sequences has been altered to be more "human-like" (i.e., more similar to human germline variable sequences). One type of humanized antibody is a CDR-grafted antibody, in which a human CDR sequence is introduced into non-human VH and VL sequences to replace the corresponding non-human CDR sequences. In one embodiment, a humanized anti-transferrin receptor antibody and an antigen-binding moiety are provided. Such antibodies can be produced by obtaining mouse anti-transferrin receptor monoclonal antibodies using conventional hybridoma techniques and then humanizing them using in vitro genetic engineering, such as those disclosed in Kasaian et al., PCT Publication No. WO 2005 / 123126 A2.

[0069] Internalized cell surface receptors: As used herein, the term "internalized cell surface receptor" refers to a cell surface receptor that is internalized by a cell in response to an external stimulus (e.g., ligand binding to a receptor). In some embodiments, the internalized cell surface receptor is internalized via endocytosis. In some embodiments, the internalized cell surface receptor is internalized via clathrin-mediated endocytosis. However, in some embodiments, the internalized cell surface receptor is internalized via a clathrin-independent pathway, such as phagocytosis, macropinocytosis, pit and raft-mediated uptake, or constitutive clathrin-independent endocytosis. In some embodiments, the internalized cell surface receptor comprises an intracellular domain, a transmembrane domain, and / or (e.g., and) an extracellular domain, which optionally also comprises a ligand-binding domain. In some embodiments, the cell surface receptor is internalized by a cell upon ligand binding. In some embodiments, the ligand may be a muscle-targeting agent or a muscle-targeting antibody. In some embodiments, the internalized cell surface receptor is a transferrin receptor.

[0070] Isolated Antibodies: As used herein, “isolated antibodies” are intended to refer to antibodies that are substantially free of other antibodies with different antigen specificities (e.g., isolated antibodies that specifically bind to the transferrin receptor are substantially free of antibodies that specifically bind to antigens other than the transferrin receptor). However, isolated antibodies that specifically bind to the transferrin receptor complex may be cross-reactive with other antigens, such as transferrin receptor molecules from other species. Furthermore, isolated antibodies may be substantially free of other cellular material and / or (e.g., and) chemicals.

[0071] Kabat Numbering: The terms “Kabat numbering,” “Kabat definition,” and “Kabat labeling” are used interchangeably herein. These terms, as accepted in the art, refer to a system for numbering amino acid residues in the variable regions of the heavy and light chains of antibodies or their antigen-binding moieties that are more variable (i.e., hypervariable) than other amino acid residues (Kabat et al. (1971) Ann. NY Acad, Sci. 190:382-391 and Kabat, EA, et al. (1991) Sequences of Proteins of Immunological Interest, Fifth Edition, US Department of Health and Human Services, NIH Publication No.). (91-3242). For the heavy chain variable region, the hypervariable region of CDR1 is amino acids 31 to 35, the hypervariable region of CDR2 is amino acids 50 to 65, and the hypervariable region of CDR3 is amino acids 95 to 102. For the light chain variable region, the hypervariable region of CDR1 is amino acids 24 to 34, the hypervariable region of CDR2 is amino acids 50 to 56, and the hypervariable region of CDR3 is amino acids 89 to 97.

[0072] Molecular payload: As used herein, the term "molecular payload" refers to a molecule or substance that plays a role in regulating biological outcomes. In some embodiments, the molecular payload is linked to or otherwise associated with a muscle target. In some embodiments, the molecular payload is a small molecule, protein, peptide, nucleic acid, or oligonucleotide. In some embodiments, the molecular payload plays a role in regulating the transcription of a DNA sequence, regulating protein expression, or regulating protein activity. In some embodiments, the molecular payload is an oligonucleotide containing a strand with a complementary region of a target gene.

[0073] Muscle Target: As used herein, the term "muscle target" refers to a molecule that specifically binds to an antigen expressed on a muscle cell. The antigen, whether intracellular or on a muscle cell, can be a membrane protein, such as an integrated membrane protein or a peripheral membrane protein. Typically, the specific binding of a muscle target to an antigen on a muscle cell facilitates the internalization of the muscle target (and any associated molecular payload) into the muscle cell. In some embodiments, the muscle target specifically binds to an internalized cell surface receptor on muscle and is internalized into the muscle cell via receptor-mediated internalization. In some embodiments, the muscle target is a small molecule, protein, peptide, nucleic acid (e.g., an aptamer), or antibody. In some embodiments, the muscle target is linked to a molecular payload.

[0074] Muscle-targeting antibody: As used herein, the term "muscle-targeting antibody" refers to a muscle-targeting agent that specifically binds to an antigen present within or on muscle cells. In some embodiments, the muscle-targeting antibody specifically binds to an antigen on muscle cells, which facilitates the internalization of the muscle-targeting antibody (and any associated molecular payload) into the muscle cells. In some embodiments, the muscle-targeting antibody specifically binds to an internalized cell surface receptor present on muscle cells. In some embodiments, the muscle-targeting antibody is an antibody that specifically binds to the transferrin receptor.

[0075] Oligonucleotides: As used herein, the term "oligonucleotide" refers to oligonucleotide compounds up to 200 nucleotides in length. Examples of oligonucleotides include, but are not limited to, RNAi oligonucleotides (e.g., siRNA, shRNA), microRNAs, spacer polymers, hybrid polymers, phosphodiesteramide morpholino, peptide nucleic acids, aptamers, and guide nucleic acids (e.g., Cas9 guide RNA). Oligonucleotides can be single-stranded or double-stranded. In some embodiments, an oligonucleotide may contain one or more modified nucleotides (e.g., 2'-O-methyl sugar modification, purine or pyrimidine modification). In some embodiments, an oligonucleotide may contain one or more modified nucleotide links. In some embodiments, an oligonucleotide may contain one or more phosphate thioester links, which may be in the Rp or Sp stereochemical conformation.

[0076] Recombinant Antibody: As used herein, the term “recombinant human antibody” is intended to include all human antibodies prepared, expressed, generated, or isolated in a recombinant manner, such as antibodies expressed using a recombinant expression vector transfected into host cells (described in more detail in this disclosure), antibodies isolated from recombinant, combinatorial human antibody libraries (Hoogenboom HR, (1997) TIB Tech. 15:62-70; Azzazy H., and Highsmith WE, (2002) Clin. Biochem. 35:425-445; Gavilondo JV, and Larrick JW (2002) BioTechniques29:128-145; Hoogenboom H., and Chames P. (2000) Immunology Today 21:371-378), and antibodies isolated from animals transgenic with human immunoglobulin genes (e.g., mice) (see, for example, Taylor, LD, et al. (1992) Nucl. Acids Res.). 20:6287-6295; Kellermann SA., and Green LL (2002) Current Opinion in Biotechnology 13:593-597; Little M. et al (2000) Immunology Today 21:364-370), or antibodies prepared, expressed, generated, or isolated by any other means involving splicing human immunoglobulin gene sequences into other DNA sequences. Such recombinant human antibodies have variable and constant regions derived from human germline immunoglobulin sequences. However, in some embodiments, such recombinant human antibodies are mutagenized in vitro (or in vivo somatic cell mutagenized when using animals transgenic with human Ig sequences), and therefore the amino acid sequences of the VH and VL regions of the recombinant antibody are sequences that, although derived from and associated with human germline VH and VL sequences, may not be naturally present in an in vivo human antibody germline library. One embodiment of this disclosure provides a fully human antibody capable of binding to the human transferrin receptor, which can be generated using techniques known in the art, such as, but not limited to, using human Ig phage libraries, such as those disclosed in Jermutus et al. PCT Publication No. WO 2005 / 007699 A2.

[0077] Complementary region: As used herein, the term "complementary region" refers to a nucleotide sequence, such as an oligonucleotide, that is fully complementary to a homologous nucleotide sequence of, for example, a target nucleic acid, such that the two nucleotide sequences can anneal to each other under physiological conditions (e.g., in a cell). In some embodiments, the complementary region is completely complementary to the homologous nucleotide sequence of the target nucleic acid. However, in some embodiments, the complementary region is partially complementary to the homologous nucleotide sequence of the target nucleic acid (e.g., at least 80%, 90%, 95%, or 99% complementary). In some embodiments, the complementary region contains 1, 2, 3, or 4 mismatches compared to the homologous nucleotide sequence of the target nucleic acid.

[0078] Specific binding: As used herein, the term "specific binding" refers to the ability of a molecule to bind to a binding partner with a degree of affinity or affinity that allows the molecule to be used to distinguish the binding partner from a suitable control in a binding assay or other binding setting. Regarding antibodies, the term "specific binding" refers to the ability of an antibody to bind to a specific antigen with a degree of affinity or affinity compared to one or more suitable reference antigens that allows the antibody to be used to distinguish the specific antigen from other antigens, for example, to the extent that it allows preferential targeting of certain cells (e.g., muscle cells) by binding to antigens as described herein. In some embodiments, if the antibody binds to the target K... D For at least about 10 -4 M, 10 -5 M, 10 -6 M, 10 -7 M, 10 -8 M, 10 -9 M, 10 -10 M, 10 -11 M, 10 -12 M, 10 -13 If M is smaller, the antibody binds specifically to the target. In some embodiments, the antibody binds specifically to the transferrin receptor (e.g., an epitope of the apical domain of the transferrin receptor).

[0079] Object: As used herein, the term "object" refers to a mammal. In some embodiments, the object is a non-human primate or rodent. In some embodiments, the object is a human. In some embodiments, the object is a patient, such as a person who has or is suspected of having a disease. In some embodiments, the object is a person who has or is suspected of having FSHD.

[0080] Transferrin receptor: As used herein, the term "transferrin receptor" (also known as TFRC, CD71, p90, TFR, or TFR1) refers to an internalized cell surface receptor that binds to transferrin to facilitate iron uptake via endocytosis. In some embodiments, the transferrin receptor may be of human origin (NCBI gene ID 7037), non-human primate origin (e.g., NCBI gene ID 711568 or NCBI gene ID 102136007), or rodent origin (e.g., NCBI gene ID 22042). Additionally, several human transcript variants encoding different isotypes of the receptor have been characterized (e.g., as annotated with the following GenBankRefSeq accession numbers: NP_001121620.1, NP_003225.2, NP_001300894.1, and NP_001300895.1).

[0081] 2'-Modified Nucleosides: The terms "2'-modified nucleosides" and "2'-modified ribonucleosides" are used interchangeably herein and refer to nucleosides having a modified sugar moiety at the 2' position. In some embodiments, the 2'-modified nucleoside is a 2'-4' bicyclic nucleoside, wherein the 2' and 4' positions of the sugar are bridged (e.g., by methylene, ethylene, or (S)-restricted ethyl bridging). In some embodiments, the 2'-modified nucleoside is a non-bicyclic 2'-modified nucleoside, for example, wherein the 2' position of the sugar moiety is substituted. Some non-limiting examples of 2'-modified nucleosides include: 2'-deoxy, 2'-fluorine (2'-F), 2'-O-methyl (2'-O-Me), 2'-O-methoxyethyl (2'-MOE), 2'-O-aminopropyl (2'-O-AP), 2'-O-dimethylaminoethyl (2'-O-DMAOE), 2'-O-dimethylaminopropyl (2'-O-DMAP), 2'-O-dimethylaminoethyloxyethyl (2'-O-DMAEOE), 2'-ON-methylacetamido (2'-O-NMA), locked nucleic acids (LNA, methylene-bridged nucleic acids), ethylene-bridged nucleic acids (ENA), and (S)-bound ethyl-bridged nucleic acids (cEt). In some embodiments, the 2'-modified nucleosides described herein are high-affinity modified nucleotides and oligonucleotides comprising 2'-modified nucleotides that have increased affinity for target sequences relative to unmodified oligonucleotides. Below are some examples of the structures of 2'-modified nucleosides:

[0082]

[0083] II. Complex

[0084] This document provides for complexes comprising a target agent (e.g., an antibody) covalently linked to a molecular payload. In some embodiments, the complex comprises a muscle-targeting antibody covalently linked to an oligonucleotide. The complex may comprise an antibody that specifically binds to a single antigenic site or binds to at least two antigenic sites that may be present on the same or different antigens.

[0085] The complex can be used to modulate the activity or function of at least one gene, protein, and / or (e.g., and) nucleic acid. In some embodiments, the molecular payload present with the complex is responsible for the regulation of the gene, protein, and / or (e.g., and) nucleic acid. The molecular payload can be a small molecule, protein, nucleic acid, oligonucleotide, or any molecular entity capable of modulating the activity or function of a gene, protein, and / or (e.g., and) nucleic acid in a cell. In some embodiments, the molecular payload is an oligonucleotide targeting DUX4 in muscle cells.

[0086] In some implementations, the complex comprises a muscle target, such as an anti-transferrin receptor antibody, covalently linked to a molecular payload (e.g., an antisense oligonucleotide targeting DUX4).

[0087] A. Muscle-targeting agents

[0088] Some aspects of this disclosure provide muscle targeting agents, for example, for delivering molecular payloads to muscle cells. In some embodiments, such muscle targeting agents are capable of binding to muscle cells, for example, by specifically binding to an antigen on the muscle cell, and delivering the associated molecular payload to the muscle cell. In some embodiments, the molecular payload binds to the muscle targeting agent (e.g., covalently) and is internalized into the muscle cell after the muscle targeting agent binds to the antigen on the muscle cell, for example, through endocytosis. It should be understood that various types of muscle targeting agents can be used according to this disclosure. For example, muscle targeting agents may comprise, or consist of, nucleic acids (e.g., DNA or RNA), peptides (e.g., antibodies), lipids (e.g., microvesicles), or glycosides (e.g., polysaccharides). Exemplary muscle targeting agents are described in further detail herein; however, it should be understood that the exemplary muscle targeting agents provided herein are not intended to be limiting.

[0089] Some aspects of this disclosure provide muscle-targeting agents that specifically bind to antigens on muscles (e.g., skeletal muscle, smooth muscle, or cardiac muscle). In some embodiments, any muscle-targeting agent provided herein binds to (e.g., specifically binds to) antigens on skeletal muscle cells, smooth muscle cells, and / or (e.g., and) cardiac muscle cells.

[0090] By interacting with muscle-specific cell surface recognition elements (e.g., cell membrane proteins), both tissue localization and selective uptake into muscle cells can be achieved. In some embodiments, molecules that serve as substrates for muscle uptake transporters can be used to deliver molecular payloads into muscle tissue. Binding to muscle surface recognition elements is followed by endocytosis, which can allow even large molecules (e.g., antibodies) to enter muscle cells. As another example, molecular payloads conjugated to transferrin or anti-transferrin receptor antibodies can be taken up by muscle cells by binding to transferrin receptors and then endocytosed, for example, via clathrin-mediated endocytosis.

[0091] The use of muscle-targeting agents can be used to concentrate molecular payloads (e.g., oligonucleotides) in muscle while reducing toxicity associated with effects in other tissues. In some embodiments, the muscle-targeting agent concentrates the bound molecular payload in muscle cells compared to another cell type within the subject. In some embodiments, the muscle-targeting agent concentrates the bound molecular payload in muscle cells (e.g., skeletal muscle, smooth muscle, or cardiomyocytes) in an amount at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 30, 40, 50, 60, 70, 80, 90, or 100 times higher than the amount found in non-muscle cells (e.g., liver, neurons, blood, or fat cells). In some embodiments, when the molecular payload is delivered to the subject while bound to the muscle-targeting agent, its toxicity in the subject is reduced by at least 1%, 2%, 3%, 4%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 90%, or 95%.

[0092] In some implementations, muscle recognition elements (e.g., myocyte antigens) may be required to achieve muscle selectivity. As an example, a muscle target may be a small molecule that serves as a substrate for a transporter that specifically takes over the muscle. As another example, a muscle target may be an antibody that enters muscle cells via transporter-mediated endocytosis. As yet another example, a muscle target may be a ligand that binds to cell surface receptors on muscle cells. It should be understood that while transporter-based approaches provide a direct pathway for cell entry, receptor-based targeting may involve stimulating endocytosis to reach the desired site of action.

[0093] i. Muscle-targeting antibodies

[0094] In some embodiments, the muscle target is an antibody. Generally, the high specificity of antibodies to their target antigens offers the potential for selectively targeting muscle cells (e.g., skeletal muscle, smooth muscle, and / or, for example, cardiomyocytes). This specificity can also limit off-target toxicity. Several examples of antibodies capable of targeting muscle cell surface antigens have been reported and are within the scope of this disclosure. For example, antibodies targeting the surface of muscle cells are described in the following: Arahata K., et al. “Immunostaining of skeletal and cardiac muscle surface membrane with antibody against Duchenne muscular dystrophy peptide” Nature 1988; 333: 861-3; Song K.S., et al. “Expression of caveolin-3 in skeletal, cardiac, and smoothmuscle cells. Caveolin-3 is a component of the sarcolemma and co-fractionates with dystrophin and dystrophin-associated glycoproteins” J Biol Chem 1996;271: 15160-5; and Weisbart RH et al., “Cell type specific targeted intracellular delivery into muscle of a monoclonal antibody that binds myosinIIb” Mol Immunol. 2003 Mar, 39(13):78309; All of their contents are incorporated into this paper by reference.

[0095] a. Anti-transferrin receptor antibody

[0096] Some aspects of this disclosure are based on the understanding that substances that bind to the transferrin receptor (e.g., anti-transferrin receptor antibodies) can target muscle cells. The transferrin receptor is an internalized cell surface receptor that transports transferrin across the cell membrane and participates in the regulation and homeostasis of intracellular iron levels. Some aspects of this disclosure provide transferrin receptor-binding proteins capable of binding to the transferrin receptor. Therefore, some aspects of this disclosure provide binding proteins (e.g., antibodies) that bind to the transferrin receptor. In some embodiments, the binding protein that binds to the transferrin receptor is internalized into muscle cells along with any bound molecular payload. Antibodies that bind to the transferrin receptor as used herein may be interchangeably referred to as transferrin receptor antibodies, anti-transferrin receptor antibodies, or anti-TfR antibodies. Antibodies that bind to the transferrin receptor (e.g., specifically) can be internalized into cells after binding to the transferrin receptor, for example, through receptor-mediated endocytosis.

[0097] It should be understood that several known methods (e.g., library design using phage display) can be used to generate, synthesize, and / or (e.g., and) derive anti-transferrin receptor antibodies. Exemplary methods have been characterized in the art and are incorporated by reference (Díez, P. et al. “High-throughput phage-display screening in arrayformat”, Enzyme and microbial technology, 2015, 79, 34-41.; Christoph MHand Stanley, JR “Antibody Phage Display: Technique and Applications” JInvest Dermatol. 2014, 134:2.; Engleman, Edgar (Ed.) “Human Hybridomas and Monoclonal Antibodies.” 1985, Springer). In other embodiments, anti-transferrin antibodies have previously been characterized or disclosed.Antibodies that specifically bind to the transferrin receptor are known in the art (see, for example, U.S. Patent No. 4,364,934, filed December 4, 1979, “Monoclonal antibody to a human earlythymocyte antigen and methods for preparing same”; U.S. Patent No. 8,409,573, filed June 14, 2006, “Anti-CD71 monoclonal antibodies and uses thereof for treating malignant tumor cells”; U.S. Patent No. 9,708,406, filed May 20, 2014, “Anti-transferrin receptor antibodies and methods of use”; U.S. Patent No. 9,611,323, filed December 19, 2014, “Low affinity blood brain barrier receptor antibodies and uses therefor”; WO 2015 / 098989, filed December 24, 2014, “Novel anti-Transferrin receptor antibody that passes through blood-brain barrier”; Schneider C. et al. al. "Structural features of the cell surface receptor for transferrin that is recognized by the monoclonal antibody OKT9." J Biol Chem. 1982, 257:14, 8516-8522.; Lee et al. "Targeting Rat Anti-Mouse Transferrin Receptor Monoclonal Antibodies through Blood-Brain Barrier in Mouse" 2000, J Pharmacol. Exp. Ther., 292: 1048-1052).

[0098] In some aspects, novel anti-TfR antibodies are provided herein for use as muscle targeting agents (e.g., in muscle targeting complexes). In some embodiments, the anti-TfR antibodies described herein bind to transferrin receptors with high specificity and affinity. In some embodiments, the anti-TfR antibodies described herein specifically bind to any extracellular site of the transferrin receptor or an epitope exposed to the antibody. In some embodiments, the anti-TfR antibodies provided herein specifically bind to transferrin receptors derived from humans, non-human primates, mice, rats, etc. In some embodiments, the anti-TfR antibodies provided herein bind to human transferrin receptors. In some embodiments, the anti-TfR antibodies described herein bind to amino acid segments of human or non-human primate transferrin receptors (as provided in SEQ ID NO: 242 to 245). In some embodiments, the anti-TfR antibodies described herein bind to amino acid segments corresponding to amino acids 90 to 96 of the human transferrin receptor (as shown in SEQ ID NO: 242) that are not located in the apical domain of the transferrin receptor.

[0099] In some implementations, the anti-TFR antibody is at least about 10 -4 M, 10 -5 M, 10 -6 M, 10 -7 M, 10 -8 M, 10 -9 M, 10 -10 M, 10 -11 M, 10 -12 M, 10 -13 M or smaller binding affinity (e.g., as indicated by Kd) specifically binds to TfR1 (e.g., human or non-human primate TfR1). In some embodiments, the anti-TfR antibodies described herein bind to TfR1 with a KD in the range of anamo. In some embodiments, the anti-TfR antibodies described herein selectively bind to transferrin receptor 1 (TfR1) but not to transferrin receptor 2 (TfR2). In some embodiments, the anti-TfR antibodies described herein bind to human TfR1 and cynomolgus monkey TfR1 (e.g., Kd is 10). -7 M, 10 -8 M, 10 -9 M, 10 -10 M, 10 -11 M, 10 -12 M, 10 -13(M or smaller), but does not bind to mouse TfR1. The affinity and binding kinetics of anti-TfR antibodies can be tested using any suitable method, including but not limited to biosensor technologies (e.g., OCTET or BIACORE). In some embodiments, the binding of any of the anti-TfR antibodies described herein does not compete with or inhibit the binding of transferrin to TfR1. In some embodiments, the binding of any of the anti-TfR antibodies described herein does not compete with or inhibit the binding of HFE-β-2-microglobulin to TfR1.

[0100] The exemplary human transferrin receptor amino acid sequence corresponding to NCBI sequence NP_003225.2 (transferrin receptor protein 1 isotype 1, Homo sapiens) is as follows:

[0101] .

[0102] The exemplary non-human primate transferrin receptor amino acid sequence corresponding to the NCBI sequence NP_001244232.1 (transferrin receptor protein 1, rhesus monkey (Macacamulatta)) is as follows:

[0103] .

[0104] The exemplary non-human primate transferrin receptor amino acid sequence corresponding to the NCBI sequence XP_005545315.1 (transferrin receptor protein 1, cynomolgus monkey) is as follows:

[0105] .

[0106] The exemplary mouse transferrin receptor amino acid sequence corresponding to NCBI sequence NP_001344227.1 (transferrin receptor protein 1, mus musculus) is as follows:

[0107] .

[0108] In some implementations, the anti-transferrin receptor antibody binds to the following receptor amino acid segment:

[0109] ,

[0110] Furthermore, it does not inhibit the binding interaction between the transferrin receptor and transferrin and / or (e.g., and) human hemochromatosis protein (also known as HFE). In some embodiments, the anti-transferrin receptor antibody described herein does not bind to the epitope in SEQ ID NO: 246.

[0111] Suitable methods can be used to obtain and / or (e.g., and) generate antibodies, antibody fragments, or antigen-binding agents, for example, by using recombinant DNA protocols. In some embodiments, antibodies can also be generated by the production of hybridomas (see, for example, Kohler, G and Milstein, C. “Continuous cultures of fused cells secreting antibody of predefined specificity” Nature, 1975, 256: 495-497). The target antigen can be used as an immunogen in any form or entity (e.g., recombinant or naturally occurring forms or entities). Hybridomas are screened using standard methods (e.g., ELISA screening) to identify at least one hybridoma that produces an antibody targeting a specific antigen. Antibodies can also be generated by screening for protein expression libraries expressing antibodies (e.g., phage display libraries). In some embodiments, phage display library designs may also be used (see, for example, U.S. Patent No. 5,223,409, filed March 1, 1991, “Directed evolution of novel binding proteins”; WO 1992 / 18619, filed April 10, 1992, “Heterodimeric receptor libraries using phagemids”; WO1991 / 17271, filed May 1, 1991, “Recombinant library screening methods”; WO1992 / 20791, filed May 15, 1992, “Methods for producing members of specific binding pairs”; WO 1992 / 15679, filed February 28, 1992, “Improved epitope displaying phage”). In some embodiments, the target antigen may be used for immunization of non-human animals, such as rodents or goats. In some implementations, antibodies are then obtained from non-human animals and optionally modified using various methods (e.g., using recombinant DNA technology). Other examples of antibody production and methods are known in the art (see, for example, Harlow et al., “Antibodies: A Laboratory Manual”, Cold Spring Harbor Laboratory, 1988.).

[0112] In some embodiments, the antibody is modified, for example, by glycosylation, phosphorylation, SUMOylation, and / or (e.g., and) methylation. In some embodiments, the antibody is a glycosylated antibody conjugated to one or more sugar or carbohydrate molecules. In some embodiments, one or more sugar or carbohydrate molecules are conjugated to the antibody by N-glycosylation, O-glycosylation, C-glycosylation, glycosylphosphatidylinositol (GPI-anchored attachment), and / or (e.g., and) phosphorylated glycosylation. In some embodiments, one or more sugar or carbohydrate molecules are monosaccharides, disaccharides, oligosaccharides, or glycans. In some embodiments, one or more sugar or carbohydrate molecules are branched oligosaccharides or branched glycans. In some embodiments, one or more sugar or carbohydrate molecules comprise mannose units, glucose units, N-acetylglucosamine units, N-acetylgalactosamine units, galactose units, fucose units, or phospholipid units. In some embodiments, about 1 to 10, about 1 to 5, about 5 to 10, about 1 to 4, about 1 to 3, or about 2 sugar molecules are present. In some embodiments, the glycosylated antibody is fully or partially glycosylated. In some embodiments, the antibody is glycosylated by a chemical reaction or by an enzymatic means. In some embodiments, the antibody is glycosylated in vitro or intracellularly, optionally lacking enzymes in the N- or O-glycosylation pathway, such as glycosyltransferases. In some embodiments, the antibody is functionalized with sugar or carbohydrate molecules, as described in International Patent Application Publication WO2014065661, published May 1, 2014, entitled "Modified antibody, antibody-conjugate and process for the preparation thereof".

[0113] In some embodiments, the anti-TfR antibody of this disclosure comprises a VL domain and / or (e.g., and) a VH domain selected from any of the anti-TfR antibodies in Table 2, and comprises a constant region comprising the amino acid sequence of the constant region of an IgG, IgE, IgM, IgD, IgA, or IgY immunoglobulin molecule, any class of immunoglobulin molecules (e.g., IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2), or any subclass (e.g., IgG2a and IgG2b). Some non-limiting examples of human constant regions are described in the art, for example, see above, Kabat EA et al., (1991).

[0114] Table 2 provides some non-restrictive examples of heavy chain variable domains and light chain variable domains, as well as CDR sequences, for anti-TfR antibodies.

[0115] Table 2. Some examples of anti-TfR1 antibodies (based on IMGT)® (Defined CDR)

[0116]

[0117]

[0118]

[0119]

[0120]

[0121]

[0122] In some embodiments, the anti-TfR antibody of this disclosure comprises one or more CDR-H (e.g., CDR-H1, CDR-H2, and CDR-H3) amino acid sequences selected from any of the anti-TfR antibodies in Table 2. In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3 as provided for any of the antibodies selected from Table 2. In some embodiments, the anti-TfR antibody of this disclosure comprises one or more CDR-L (e.g., CDR-L1, CDR-L2, and CDR-L3) amino acid sequences selected from any of the anti-TfR antibodies in Table 2. In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3 as provided for any of the anti-TfR antibodies selected from Table 2.

[0123] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2, and CDR-L3 as provided for any of the anti-TfR antibodies selected from Table 2. In some embodiments, the CDR3 domains of both the antibody heavy and light chains may play a particularly important role in the antibody's binding specificity / affinity to the antigen. Therefore, the anti-TfR antibody of this disclosure may at least comprise the CDR3 of the heavy chain and / or (e.g., and) light chain of any of the anti-TfR antibodies selected from Table 2.

[0124] In some instances, any anti-TfR antibody of this disclosure has one or more CDR (e.g., CDR-H or CDR-L) sequences substantially similar to any CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2 and / or (e.g., and) CDR-L3 sequences of an anti-TfR antibody selected from Table 2. In some embodiments, the position of one or more CDRs of the antibody described herein along the VH (e.g., CDR-H1, CDR-H2 or CDR-H3) and / or (e.g., and) VL (e.g., CDR-L1, CDR-L2 or CDR-L3) regions may vary by one, two, three, four, five or six amino acid positions, provided that immune-specific binding to the transferrin receptor (e.g., human transferrin receptor) is maintained (e.g., substantially maintaining binding to the original antibody from which it is derived, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%). For example, in some embodiments, the location of the CDR of any antibody described herein can be defined by shifting the N-terminal and / or (e.g., and) C-terminal boundary of the CDR relative to the CDR location of any antibody described herein by one, two, three, four, five, or six amino acids, as long as immune-specific binding to the transferrin receptor (e.g., human transferrin receptor) is maintained (e.g., substantially maintaining binding to the original antibody from which it is derived, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%). In another embodiment, the length of one or more CDRs of the antibody described herein along the VH (e.g., CDR-H1, CDR-H2, or CDR-H3) and / or (e.g., and) VL (e.g., CDR-L1, CDR-L2, or CDR-L3) regions may be altered (e.g., become shorter or longer) by one, two, three, four, five, or more amino acids, as long as immune-specific binding to the transferrin receptor (e.g., human transferrin receptor) is maintained (e.g., substantially maintaining binding to the original antibody from which it is derived, e.g., at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%).

[0125] Therefore, in some embodiments, the CDR-L1, CDR-L2, CDR-L3, CDR-H1, CDR-H2 and / or (e.g., and) CDR-H3 described herein may be one, two, three, four, five or more amino acids shorter than one or more CDRs described herein (e.g., CDRs of any anti-TfR antibody selected from Table 2), as long as immune-specific binding to the transferrin receptor (e.g., human transferrin receptor) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%) relative to the binding of the original antibody from which it is derived. In some embodiments, the CDR-L1, CDR-L2, CDR-L3, CDR-H1, CDR-H2 and / or (e.g., and) CDR-H3 described herein may be one, two, three, four, five or more amino acids longer than one or more CDRs described herein (e.g., CDRs selected from any anti-TfR antibody in Table 2), as long as immune-specific binding to the transferrin receptor (e.g., human transferrin receptor) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%) relative to the binding of the original antibody from which it is derived. In some embodiments, the amino moiety of CDR-L1, CDR-L2, CDR-L3, CDR-H1, CDR-H2 and / or (e.g., and) CDR-H3 described herein may be extended by one, two, three, four, five or more amino acids compared to one or more CDRs described herein (e.g., CDRs selected from any anti-TfR antibody in Table 2), as long as the immune-specific binding to the transferrin receptor (e.g., human transferrin receptor) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%) relative to the binding of the original antibody from which it is derived. In some embodiments, the carboxyl moiety of CDR-L1, CDR-L2, CDR-L3, CDR-H1, CDR-H2 and / or (e.g., and) CDR-H3 described herein may be extended by one, two, three, four, five or more amino acids compared to one or more CDRs described herein (e.g., CDRs selected from any anti-TfR antibody in Table 2), as long as the immune-specific binding to the transferrin receptor (e.g., human transferrin receptor) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%) relative to the binding of the original antibody from which it is derived.In some embodiments, the amino moiety of CDR-L1, CDR-L2, CDR-L3, CDR-H1, CDR-H2 and / or (e.g., and) CDR-H3 described herein may be shortened by one, two, three, four, five or more amino acids compared to one or more CDRs described herein (e.g., CDRs selected from any anti-TfR antibody in Table 2), as long as immune-specific binding to the transferrin receptor (e.g., human transferrin receptor) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%) relative to the binding of the original antibody from which it is derived. In some embodiments, the carboxyl moiety of CDR-L1, CDR-L2, CDR-L3, CDR-H1, CDR-H2 and / or (e.g., and) CDR-H3 described herein may be shortened by one, two, three, four, five or more amino acids compared to one or more CDRs described herein (e.g., CDRs selected from any anti-TfR antibody in Table 2), as long as immune-specific binding to the transferrin receptor (e.g., human transferrin receptor) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%) relative to the binding of the original antibody from which it is derived. Any method may be used to determine whether immune-specific binding to the transferrin receptor (e.g., human transferrin receptor) is maintained, for example using binding assays and conditions described in the art.

[0126] In some instances, any anti-TfR antibody of this disclosure has one or more CDR (e.g., CDR-H or CDR-L) sequences substantially similar to any of the anti-TfR antibodies selected from Table 2. For example, an antibody may comprise one or more CDR sequences selected from Table 2 of any anti-TfR antibody, containing up to 5, 4, 3, 2, or 1 amino acid residue variations compared to the corresponding CDR region of any CDR provided herein (e.g., CDRs of any anti-TfR antibody selected from Table 2), provided that immune-specific binding to the transferrin receptor (e.g., human transferrin receptor) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%) relative to the binding of the original antibody from which it is derived. In some embodiments, any amino acid variation in any CDR provided herein may be a conserved variation. Conserved variations may be introduced into the CDR at locations where residues are unlikely to participate in interaction with the transferrin receptor protein (e.g., human transferrin receptor protein) (e.g., as determined based on crystal structure). Some aspects of this disclosure provide anti-TfR antibodies comprising one or more heavy chain variable (VH) domains and / or (e.g., and) light chain variable (VL) domains as provided herein. In some embodiments, any VH domain provided herein comprises one or more CDR-H sequences (e.g., CDR-H1, CDR-H2, and CDR-H3) as provided herein, such as any CDR-H sequences provided in any of the anti-TfRs listed in Table 2. In some embodiments, any VL domain provided herein comprises one or more CDR-L sequences (e.g., CDR-L1, CDR-L2, and CDR-L3) as provided herein, such as any CDR-L sequences provided in any of the anti-TfR antibodies listed in Table 2.

[0127] In some embodiments, the anti-TfR antibody of this disclosure includes any antibody comprising a heavy chain variable domain and / or (e.g., and) a light chain variable domain selected from any anti-TfR antibody in Table 2, and variants thereof. In some embodiments, the anti-TfR antibody of this disclosure includes any antibody comprising a heavy chain variable and a light chain variable pair selected from any anti-TfR antibody in Table 2.

[0128] Some aspects of this disclosure provide anti-TfR antibodies having a heavy chain variable (VH) and / or (e.g., and) light chain variable (VL) amino acid sequence homologous to any of those described herein. In some embodiments, the anti-TfR antibody comprises a heavy chain variable sequence or light chain variable sequence having at least 75% (e.g., 80%, 85%, 90%, 95%, 98%, or 99%) identity with a heavy chain variable sequence or light chain variable sequence selected from any of the anti-TfR antibodies in Table 2. In some embodiments, the homologous heavy chain variable and / or (e.g., and) light chain variable amino acid sequences remain unchanged within any CDR sequences provided herein. For example, in some embodiments, the degree of sequence variation (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) may occur in the heavy chain variable and / or (e.g., and) light chain variable sequences excluding any CDR sequences provided herein. In some implementations, any anti-TfR antibody provided herein comprises a heavy chain variable sequence and a light chain variable sequence, which comprises a frame sequence having at least 75%, 80%, 85%, 90%, 95%, 98%, or 99% identity with a frame sequence selected from any anti-TfR antibody in Table 2.

[0129] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3 having a heavy chain variable domain having the amino acid sequence of SEQ ID NO: 7. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3 having a light chain variable domain having the amino acid sequence of SEQ ID NO: 8.

[0130] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 1, CDR-H2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 2, CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 3, CDR-L1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 4, CDR-L2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 5, and CDR-L3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 6.

[0131] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having the amino acid sequence of SEQ ID NO: 1; CDR-H2 having the amino acid sequence of SEQ ID NO: 2, wherein an amino acid substitution is made at position 5 (e.g., the asparagine at position 5 is replaced by any of the following: Arg(R), Lys(K), Asp(D), Glu(E), Gln(Q), His(H), Ser(S), Thr(T), Tyr(Y), Cys(C), Trp(W), Met(M), Ala(A), Ile(I), Leu(L), Phe(F), Val(V), Pro(P), Gly(G)); and CDR-H3 having the amino acid sequence of SEQ ID NO: 3. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: CDR-L1 having the amino acid sequence of SEQ ID NO: 4; CDR-L2 having the amino acid sequence of SEQ ID NO: 5; and CDR-L3 having the amino acid sequence of SEQ ID NO: 6. In some embodiments, the amino acid substitution at position 5 of CDR-H2 shown in SEQ ID NO: 2 is N5T or N5S.

[0132] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having the amino acid sequence of SEQ ID NO: 1; CDR-H2 having the amino acid sequence of SEQ ID NO: 266 or SEQ ID NO: 80; and CDR-H3 having the amino acid sequence of SEQ ID NO: 3. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises: CDR-L1 having the amino acid sequence of SEQ ID NO: 4; CDR-L2 having the amino acid sequence of SEQ ID NO: 5; and CDR-L3 having the amino acid sequence of SEQ ID NO: 6.

[0133] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which, compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 1, CDR-H2 having the amino acid sequence of SEQ ID NO: 2, SEQ ID NO: 266, or SEQ ID NO: 80, and CDR-H3 having the amino acid sequence of SEQ ID NO: 3, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation). As used anywhere in this disclosure, “common” means that the total number of amino acid variations in all three heavy chain CDRs is within the defined range. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 4, CDR-L2 having the amino acid sequence of SEQ ID NO: 5, and CDR-L3 having the amino acid sequence of SEQ ID NO: 6.

[0134] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which together share at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-H1 having the amino acid sequence of SEQ ID NO: 1, CDR-H2 having the amino acid sequence of SEQ ID NO: 2, SEQ ID NO: 266, or SEQ ID NO: 80, and CDR-H3 having the amino acid sequence of SEQ ID NO: 3. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-L1 having the amino acid sequence of SEQ ID NO: 4, CDR-L2 having the amino acid sequence of SEQ ID NO: 5, and CDR-L3 having the amino acid sequence of SEQ ID NO: 6.

[0135] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 1; CDR-H2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 2, SEQ ID NO: 266, or SEQ ID NO: 80; and / or (e.g., and) CDR-H3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 3. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: CDR-L1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 4; CDR-L2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 5; and / or (e.g., and) CDR-L3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 6.

[0136] In some embodiments, the anti-TfR antibody of this disclosure comprises VH containing the amino acid sequence of SEQ ID NO: 7. Alternatively or as an alternative (e.g., supplement), the anti-TfR antibody of this disclosure comprises VL containing the amino acid sequence of SEQ ID NO: 8.

[0137] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, which contains no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation) compared to the VH shown in SEQ ID NO: 7. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a VL containing no more than 25 amino acid variations compared to the VL shown in SEQ ID NO: 8 (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation).

[0138] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, said VH containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VH shown in SEQ ID NO: 7. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises VL, said VL containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in SEQ ID NO: 8.

[0139] In some embodiments, the anti-TfR antibody of this disclosure comprises VH as shown in SEQ ID NO: 7, which has an amino acid substitution at position 55 (e.g., the asparagine at position 55 is replaced by any of the following: Arg(R), Lys(K), Asp(D), Glu(E), Gln(Q), His(H), Ser(S), Thr(T), Tyr(Y), Cys(C), Trp(W), Met(M), Ala(A), Ile(I), Leu(L), Phe(F), Val(V), Pro(P), Gly(G)). Alternatively or supplementally (e.g., additionally), the anti-TfR antibody of this disclosure comprises VL as shown in SEQ ID NO: 8. In some embodiments, the amino acid substitution at position 55 of VH shown in SEQ ID NO: 7 is N55T or N55S. When VH shown in SEQ ID NO: 7 is annotated using the Kabat numbering system, amino acid position 55 in SEQ ID NO: 7 is designated as number 54. When N54T or N54S is mentioned herein, it refers to a mutation using the Kabat numbering system.

[0140] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, which contains an amino acid substitution at position 64 relative to SEQ ID NO: 7. In some embodiments, the anti-TfR antibody of this disclosure comprises VH, which contains Met at position 64 corresponding to SEQ ID NO: 7. As an alternative or supplement (e.g., a supplement), the anti-TfR antibody of this disclosure comprises VL, which contains an amino acid sequence having at least 80% (e.g., 80%, 85%, 90%, 95%, 98%, 99%, or 100%) identity with the VL shown in SEQ ID NO: 8.

[0141] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which are heavy chain variable domains having the amino acid sequence of SEQ ID NO: 15. Alternatively or supplementally (e.g., additionally), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which are light chain variable domains having the amino acid sequence of SEQ ID NO: 16.

[0142] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 9, CDR-H2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 10, CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 11, CDR-L1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 12, CDR-L2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 13, and CDR-L3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 14.

[0143] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which, compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 9, CDR-H2 having the amino acid sequence of SEQ ID NO: 10, and CDR-H3 having the amino acid sequence of SEQ ID NO: 11, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation). Alternatively or supplementally (e.g., as a supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which, compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 12, CDR-L2 having the amino acid sequence of SEQ ID NO: 13, and CDR-L3 having the amino acid sequence of SEQ ID NO: 14, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation).

[0144] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-H1 having the amino acid sequence of SEQ ID NO: 9, CDR-H2 having the amino acid sequence of SEQ ID NO: 10, and CDR-H3 having the amino acid sequence of SEQ ID NO: 11. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-L1 having the amino acid sequence of SEQ ID NO: 12, CDR-L2 having the amino acid sequence of SEQ ID NO: 13, and CDR-L3 having the amino acid sequence of SEQ ID NO: 14.

[0145] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 9; CDR-H2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 10; and / or (e.g., and) CDR-H3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 11. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: CDR-L1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 12; CDR-L2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 13; and / or (e.g., and) CDR-L3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 14.

[0146] In some embodiments, the anti-TfR antibody of this disclosure comprises VH containing the amino acid sequence of SEQ ID NO: 15. Alternatively or as an alternative (e.g., supplement), the anti-TfR antibody of this disclosure comprises VL containing the amino acid sequence of SEQ ID NO: 16.

[0147] In some embodiments, the anti-TfR antibody of this disclosure comprises a VH containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH shown in SEQ ID NO: 15. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises a VL containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VL shown in SEQ ID NO: 16.

[0148] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, said VH containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VH shown in SEQ ID NO:15. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises VL, said VL containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in SEQ ID NO:16.

[0149] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which are heavy chain variable domains having the amino acid sequence of SEQ ID NO: 23. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which are light chain variable domains having the amino acid sequence of SEQ ID NO: 24.

[0150] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 17, CDR-H2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 18, CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 19, CDR-L1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 20, CDR-L2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 21, and CDR-L3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 22.

[0151] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having the amino acid sequence of SEQ ID NO: 17, wherein an amino acid substitution is made at position 8 (e.g., the cysteine ​​at position 8 is replaced by any of the following: Arg(R), Lys(K), Asp(D), Glu(E), Gln(Q), His(H), Ser(S), Thr(T), Tyr(Y), Asn(N), Trp(W), Met(M), Ala(A), Ile(I), Leu(L), Phe(F), Val(V), Pro(P), Gly(G); CDR-H2 having the amino acid sequence of SEQ ID NO: 18; and CDR-H3 having the amino acid sequence of SEQ ID NO: 19. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: CDR-L1 having the amino acid sequence of SEQ ID NO: 20; having the amino acid sequence of SEQ ID NO: 19; CDR-L2 having the amino acid sequence of SEQ ID NO: 21; and CDR-L3 having the amino acid sequence of SEQ ID NO: 22. In some embodiments, the amino acid substitution at position 8 of CDR-H1 shown in SEQ ID NO: 17 is C8D or C8Y.

[0152] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having the amino acid sequence of SEQ ID NO: 270 or SEQ ID NO: 272; CDR-H2 having the amino acid sequence of SEQ ID NO: 18; and CDR-H3 having the amino acid sequence of SEQ ID NO: 19. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises: CDR-L1 having the amino acid sequence of SEQ ID NO: 20; CDR-L2 having the amino acid sequence of SEQ ID NO: 21; and CDR-L3 having the amino acid sequence of SEQ ID NO: 22.

[0153] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which, together with CDR-H1 having the amino acid sequence of SEQ ID NO: 17, SEQ ID NO: 270, or SEQ ID NO: 272, CDR-H2 having the amino acid sequence of SEQ ID NO: 18, and CDR-H3 having the amino acid sequence of SEQ ID NO: 19, comprise no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation). As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 20, CDR-L2 having the amino acid sequence of SEQ ID NO: 21, and CDR-L3 having the amino acid sequence of SEQ ID NO: 22.

[0154] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-H1 having the amino acid sequence of SEQ ID NO: 17, SEQ ID NO: 270, or SEQ ID NO: 272, CDR-H2 having the amino acid sequence of SEQ ID NO: 18, and CDR-H3 having the amino acid sequence of SEQ ID NO: 19. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-L1 having the amino acid sequence of SEQ ID NO: 20, CDR-L2 having the amino acid sequence of SEQ ID NO: 21, and CDR-L3 having the amino acid sequence of SEQ ID NO: 22.

[0155] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 17, SEQ ID NO: 270, or SEQ ID NO: 272; CDR-H2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 18; and / or (e.g., and) CDR-H3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 19. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: CDR-L1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 20; CDR-L2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 21; and / or (e.g., and) CDR-L3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 22.

[0156] In some embodiments, the anti-TfR antibody of this disclosure comprises VH containing the amino acid sequence of SEQ ID NO: 23. Alternatively or as an alternative (e.g., supplement), the anti-TfR antibody of this disclosure comprises VL containing the amino acid sequence of SEQ ID NO: 24.

[0157] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, which contains no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation) compared to the VH shown in SEQ ID NO: 23. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a VL containing no more than 25 amino acid variations compared to the VL shown in SEQ ID NO: 24 (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation).

[0158] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, said VH containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VH shown in SEQ ID NO:23. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises VL, said VL containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in SEQ ID NO:24.

[0159] In some embodiments, the anti-TfR antibody of this disclosure comprises VH as shown in SEQ ID NO: 23, having an amino acid substitution at position 33 (e.g., the cysteine ​​at position 33 is replaced by any of the following: Arg(R), Lys(K), Asp(D), Glu(E), Gln(Q), His(H), Ser(S), Thr(T), Tyr(Y), Asn(N), Trp(W), Met(M), Ala(A), Ile(I), Leu(L), Phe(F), Val(V), Pro(P), Gly(G)). Alternatively or supplementally (e.g., additionally), the anti-TfR antibody of this disclosure comprises VL as shown in SEQ ID NO: 24. In some embodiments, the amino acid substitution at position 33 of VH as shown in SEQ ID NO: 23 is C33D or C33Y. When VH shown in SEQ ID NO: 23 is annotated using the Kabat numbering system, the 33rd amino acid in SEQ ID NO: 23 is designated as number 33.

[0160] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which are heavy chain variable domains having the amino acid sequence of SEQ ID NO: 31. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which are light chain variable domains having the amino acid sequence of SEQ ID NO: 32.

[0161] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 25, CDR-H2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 26, CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 27, CDR-L1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 28, CDR-L2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 29, and CDR-L3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 30.

[0162] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which, compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 25, CDR-H2 having the amino acid sequence of SEQ ID NO: 26, and CDR-H3 having the amino acid sequence of SEQ ID NO: 27, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation). Alternatively or supplementally (e.g., as a supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which, compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 28, CDR-L2 having the amino acid sequence of SEQ ID NO: 29, and CDR-L3 having the amino acid sequence of SEQ ID NO: 30, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation).

[0163] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-H1 having the amino acid sequence of SEQ ID NO: 25, CDR-H2 having the amino acid sequence of SEQ ID NO: 26, and CDR-H3 having the amino acid sequence of SEQ ID NO: 27. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-L1 having the amino acid sequence of SEQ ID NO: 28, CDR-L2 having the amino acid sequence of SEQ ID NO: 29, and CDR-L3 having the amino acid sequence of SEQ ID NO: 30.

[0164] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 25; CDR-H2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 26; and / or (e.g., and) CDR-H3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 27. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: CDR-L1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 28; CDR-L2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 29; and / or (e.g., and) CDR-L3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 30.

[0165] In some embodiments, the anti-TfR antibody of this disclosure comprises VH containing the amino acid sequence of SEQ ID NO: 31. Alternatively or as an alternative (e.g., supplement), the anti-TfR antibody of this disclosure comprises VL containing the amino acid sequence of SEQ ID NO: 32.

[0166] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, which contains no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation) compared to the VH shown in SEQ ID NO: 31. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a VL containing no more than 25 amino acid variations compared to the VL shown in SEQ ID NO: 32 (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation).

[0167] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, said VH containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VH shown in SEQ ID NO:31. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises VL, said VL containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in SEQ ID NO:32.

[0168] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which are heavy chain variable domains having the amino acid sequence of SEQ ID NO: 39. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which are light chain variable domains having the amino acid sequence of SEQ ID NO: 40.

[0169] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 33, CDR-H2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 34, CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 35, CDR-L1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 36, CDR-L2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 37, and CDR-L3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 38.

[0170] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which, compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 33, CDR-H2 having the amino acid sequence of SEQ ID NO: 34, and CDR-H3 having the amino acid sequence of SEQ ID NO: 35, collectively comprise no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation). Alternatively or supplementally (e.g., as a supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which, compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 36, CDR-L2 having the amino acid sequence of SEQ ID NO: 37, and CDR-L3 having the amino acid sequence of SEQ ID NO: 38, collectively comprise no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation).

[0171] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-H1 having the amino acid sequence of SEQ ID NO: 33, CDR-H2 having the amino acid sequence of SEQ ID NO: 34, and CDR-H3 having the amino acid sequence of SEQ ID NO: 35. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-L1 having the amino acid sequence of SEQ ID NO: 36, CDR-L2 having the amino acid sequence of SEQ ID NO: 37, and CDR-L3 having the amino acid sequence of SEQ ID NO: 38.

[0172] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 33; CDR-H2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 34; and / or (e.g., and) CDR-H3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 35. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: CDR-L1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 36; CDR-L2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 37; and / or (e.g., and) CDR-L3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 38.

[0173] In some embodiments, the anti-TfR antibody of this disclosure comprises a VH containing the amino acid sequence of SEQ ID NO: 39. Alternatively or as an alternative (e.g., supplement), the anti-TfR antibody of this disclosure comprises a VL containing the amino acid sequence of SEQ ID NO: 40.

[0174] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, which contains no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation) compared to the VH shown in SEQ ID NO: 39. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a VL containing no more than 25 amino acid variations compared to the VL shown in SEQ ID NO: 40 (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation).

[0175] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, said VH containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VH shown in SEQ ID NO:39. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises VL, said VL containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in SEQ ID NO:40.

[0176] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which are heavy chain variable domains having the amino acid sequence of SEQ ID NO: 47. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which are light chain variable domains having the amino acid sequence of SEQ ID NO: 48.

[0177] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 41, CDR-H2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 42, CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 43, CDR-L1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 44, CDR-L2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 45, and CDR-L3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 46.

[0178] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which, compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 41, CDR-H2 having the amino acid sequence of SEQ ID NO: 42, and CDR-H3 having the amino acid sequence of SEQ ID NO: 43, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation). Alternatively or supplementally (e.g., as a supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which, compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 44, CDR-L2 having the amino acid sequence of SEQ ID NO: 45, and CDR-L3 having the amino acid sequence of SEQ ID NO: 46, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation).

[0179] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-H1 having the amino acid sequence of SEQ ID NO: 41, CDR-H2 having the amino acid sequence of SEQ ID NO: 42, and CDR-H3 having the amino acid sequence of SEQ ID NO: 43. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-L1 having the amino acid sequence of SEQ ID NO: 44, CDR-L2 having the amino acid sequence of SEQ ID NO: 45, and CDR-L3 having the amino acid sequence of SEQ ID NO: 46.

[0180] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 41; CDR-H2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 42; and / or (e.g., and) CDR-H3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 43. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: CDR-L1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 44; CDR-L2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 45; and / or (e.g., and) CDR-L3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 46.

[0181] In some embodiments, the anti-TfR antibody of this disclosure comprises a VH containing the amino acid sequence of SEQ ID NO: 47. Alternatively or as an alternative (e.g., supplement), the anti-TfR antibody of this disclosure comprises a VL containing the amino acid sequence of SEQ ID NO: 48.

[0182] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, which contains no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation) compared to the VH shown in SEQ ID NO: 47. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a VL containing no more than 25 amino acid variations compared to the VL shown in SEQ ID NO: 48 (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation).

[0183] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, said VH containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VH shown in SEQ ID NO:47. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises VL, said VL containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in SEQ ID NO:48.

[0184] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which are heavy chain variable domains having the amino acid sequence of SEQ ID NO: 54. Alternatively or supplementally (e.g., additionally), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which are light chain variable domains having the amino acid sequence of SEQ ID NO: 55.

[0185] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 49, CDR-H2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 50, CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 51, CDR-L1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 52, CDR-L2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 29, and CDR-L3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 53.

[0186] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which, compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 49, CDR-H2 having the amino acid sequence of SEQ ID NO: 50, and CDR-H3 having the amino acid sequence of SEQ ID NO: 51, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation). Alternatively or supplementally (e.g., as a supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which, compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 52, CDR-L2 having the amino acid sequence of SEQ ID NO: 29, and CDR-L3 having the amino acid sequence of SEQ ID NO: 53, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation).

[0187] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-H1 having the amino acid sequence of SEQ ID NO: 49, CDR-H2 having the amino acid sequence of SEQ ID NO: 50, and CDR-H3 having the amino acid sequence of SEQ ID NO: 51. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-L1 having the amino acid sequence of SEQ ID NO: 52, CDR-L2 having the amino acid sequence of SEQ ID NO: 29, and CDR-L3 having the amino acid sequence of SEQ ID NO: 53.

[0188] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 49; CDR-H2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 50; and / or (e.g., and) CDR-H3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 51. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: CDR-L1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 52; CDR-L2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 29; and / or (e.g., and) CDR-L3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 53.

[0189] In some embodiments, the anti-TfR antibody of this disclosure comprises a VH containing the amino acid sequence of SEQ ID NO: 54. Alternatively or as an alternative (e.g., supplement), the anti-TfR antibody of this disclosure comprises a VL containing the amino acid sequence of SEQ ID NO: 55.

[0190] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, which contains no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation) compared to the VH shown in SEQ ID NO: 54. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a VL containing no more than 25 amino acid variations compared to the VL shown in SEQ ID NO: 55 (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation).

[0191] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, said VH containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VH shown in SEQ ID NO:54. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises VL, said VL containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in SEQ ID NO:55.

[0192] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which are heavy chain variable domains having the amino acid sequence of SEQ ID NO: 62. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which are light chain variable domains having the amino acid sequence of SEQ ID NO: 63.

[0193] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 56, CDR-H2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 57, CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 58, CDR-L1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 59, CDR-L2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 60, and CDR-L3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 61.

[0194] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which, compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 56, CDR-H2 having the amino acid sequence of SEQ ID NO: 57, and CDR-H3 having the amino acid sequence of SEQ ID NO: 58, collectively comprise no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation). Alternatively or supplementally (e.g., as a supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which, compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 59, CDR-L2 having the amino acid sequence of SEQ ID NO: 60, and CDR-L3 having the amino acid sequence of SEQ ID NO: 61, collectively comprise no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation).

[0195] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-H1 having the amino acid sequence of SEQ ID NO: 56, CDR-H2 having the amino acid sequence of SEQ ID NO: 57, and CDR-H3 having the amino acid sequence of SEQ ID NO: 58. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-L1 having the amino acid sequence of SEQ ID NO: 59, CDR-L2 having the amino acid sequence of SEQ ID NO: 60, and CDR-L3 having the amino acid sequence of SEQ ID NO: 61.

[0196] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 56; CDR-H2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 57; and / or (e.g., and) CDR-H3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 58. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: CDR-L1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 59; CDR-L2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 60; and / or (e.g., and) CDR-L3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 61.

[0197] In some embodiments, the anti-TfR antibody of this disclosure comprises a VH containing the amino acid sequence of SEQ ID NO: 62. Alternatively or as an alternative (e.g., supplement), the anti-TfR antibody of this disclosure comprises a VL containing the amino acid sequence of SEQ ID NO: 63.

[0198] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, which contains no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation) compared to the VH shown in SEQ ID NO: 62. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a VL containing no more than 25 amino acid variations compared to the VL shown in SEQ ID NO: 63 (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation).

[0199] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, said VH containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VH shown in SEQ ID NO:62. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises VL, said VL containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in SEQ ID NO:63.

[0200] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which are heavy chain variable domains having the amino acid sequence of SEQ ID NO: 70. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which are light chain variable domains having the amino acid sequence of SEQ ID NO: 71.

[0201] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 64, CDR-H2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 65, CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 66, CDR-L1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 67, CDR-L2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 68, and CDR-L3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 69.

[0202] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which, together with CDR-H1 having the amino acid sequence of SEQ ID NO: 64, CDR-H2 having the amino acid sequence of SEQ ID NO: 65, and CDR-H3 having the amino acid sequence of SEQ ID NO: 66, collectively comprise no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation). Alternatively or supplementally (e.g., as a supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which, together with CDR-L1 having the amino acid sequence of SEQ ID NO: 67, CDR-L2 having the amino acid sequence of SEQ ID NO: 68, and CDR-L3 having the amino acid sequence of SEQ ID NO: 69, collectively comprise no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation).

[0203] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-H1 having the amino acid sequence of SEQ ID NO: 64, CDR-H2 having the amino acid sequence of SEQ ID NO: 65, and CDR-H3 having the amino acid sequence of SEQ ID NO: 66. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-L1 having the amino acid sequence of SEQ ID NO: 67, CDR-L2 having the amino acid sequence of SEQ ID NO: 68, and CDR-L3 having the amino acid sequence of SEQ ID NO: 69.

[0204] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 64; CDR-H2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 65; and / or (e.g., and) CDR-H3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 66. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: CDR-L1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 67; CDR-L2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 68; and / or (e.g., and) CDR-L3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 69.

[0205] In some embodiments, the anti-TfR antibody of this disclosure comprises a VH containing the amino acid sequence of SEQ ID NO: 70. Alternatively or as an alternative (e.g., supplement), the anti-TfR antibody of this disclosure comprises a VL containing the amino acid sequence of SEQ ID NO: 71.

[0206] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, which contains no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation) compared to the VH shown in SEQ ID NO: 70. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a VL containing no more than 25 amino acid variations compared to the VL shown in SEQ ID NO: 71 (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation).

[0207] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, said VH containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VH shown in SEQ ID NO:70. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises VL, said VL containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in SEQ ID NO:71.

[0208] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which are heavy chain variable domains having the amino acid sequence of SEQ ID NO: 77. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which are light chain variable domains having the amino acid sequence of SEQ ID NO: 78.

[0209] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 72, CDR-H2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 73, CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 74, CDR-L1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 75, CDR-L2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 45, and CDR-L3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 76.

[0210] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which, compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 72, CDR-H2 having the amino acid sequence of SEQ ID NO: 73, and CDR-H3 having the amino acid sequence of SEQ ID NO: 74, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation). Alternatively or supplementally (e.g., as a supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which, compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 75, CDR-L2 having the amino acid sequence of SEQ ID NO: 45, and CDR-L3 having the amino acid sequence of SEQ ID NO: 76, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation).

[0211] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-H1 having the amino acid sequence of SEQ ID NO: 72, CDR-H2 having the amino acid sequence of SEQ ID NO: 73, and CDR-H3 having the amino acid sequence of SEQ ID NO: 74. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-L1 having the amino acid sequence of SEQ ID NO: 75, CDR-L2 having the amino acid sequence of SEQ ID NO: 45, and CDR-L3 having the amino acid sequence of SEQ ID NO: 76.

[0212] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 72; CDR-H2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 73; and / or (e.g., and) CDR-H3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 74. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: CDR-L1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 75; CDR-L2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 45; and / or (e.g., and) CDR-L3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 76.

[0213] In some embodiments, the anti-TfR antibody of this disclosure comprises a VH containing the amino acid sequence of SEQ ID NO: 77. Alternatively or as an alternative (e.g., supplement), the anti-TfR antibody of this disclosure comprises a VL containing the amino acid sequence of SEQ ID NO: 78.

[0214] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, which contains no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation) compared to the VH shown in SEQ ID NO: 77. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a VL containing no more than 25 amino acid variations compared to the VL shown in SEQ ID NO: 78 (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation).

[0215] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, said VH containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VH shown in SEQ ID NO:77. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises VL, said VL containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in SEQ ID NO:78.

[0216] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which are heavy chain variable domains having the amino acid sequence of SEQ ID NO: 85. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which are light chain variable domains having the amino acid sequence of SEQ ID NO: 86.

[0217] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 79, CDR-H2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 80, CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 81, CDR-L1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 82, CDR-L2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 83, and CDR-L3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 84.

[0218] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which, compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 79, CDR-H2 having the amino acid sequence of SEQ ID NO: 80, and CDR-H3 having the amino acid sequence of SEQ ID NO: 81, collectively comprise no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation). Alternatively or supplementally (e.g., as a supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which, compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 82, CDR-L2 having the amino acid sequence of SEQ ID NO: 83, and CDR-L3 having the amino acid sequence of SEQ ID NO: 84, collectively comprise no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation).

[0219] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-H1 having the amino acid sequence of SEQ ID NO: 79, CDR-H2 having the amino acid sequence of SEQ ID NO: 80, and CDR-H3 having the amino acid sequence of SEQ ID NO: 81. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-L1 having the amino acid sequence of SEQ ID NO: 82, CDR-L2 having the amino acid sequence of SEQ ID NO: 83, and CDR-L3 having the amino acid sequence of SEQ ID NO: 84.

[0220] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 79; CDR-H2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 80; and / or (e.g., and) CDR-H3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 81. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: CDR-L1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 82; CDR-L2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 83; and / or (e.g., and) CDR-L3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 84.

[0221] In some embodiments, the anti-TfR antibody of this disclosure comprises a VH containing the amino acid sequence of SEQ ID NO: 85. Alternatively or as an alternative (e.g., supplement), the anti-TfR antibody of this disclosure comprises a VL containing the amino acid sequence of SEQ ID NO: 86.

[0222] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, which contains no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation) compared to the VH shown in SEQ ID NO: 85. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a VL containing no more than 25 amino acid variations compared to the VL shown in SEQ ID NO: 86 (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation).

[0223] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, said VH containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VH shown in SEQ ID NO:85. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises VL, said VL containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in SEQ ID NO:86.

[0224] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which are heavy chain variable domains having the amino acid sequence of SEQ ID NO: 89. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which are light chain variable domains having the amino acid sequence of SEQ ID NO: 90.

[0225] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 72, CDR-H2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 87, CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 74, CDR-L1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 75, CDR-L2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 45, and CDR-L3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 88.

[0226] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which, compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 72, CDR-H2 having the amino acid sequence of SEQ ID NO: 87, and CDR-H3 having the amino acid sequence of SEQ ID NO: 74, collectively comprise no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation). Alternatively or supplementally (e.g., as a supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which, compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 75, CDR-L2 having the amino acid sequence of SEQ ID NO: 45, and CDR-L3 having the amino acid sequence of SEQ ID NO: 88, collectively comprise no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation).

[0227] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-H1 having the amino acid sequence of SEQ ID NO: 72, CDR-H2 having the amino acid sequence of SEQ ID NO: 87, and CDR-H3 having the amino acid sequence of SEQ ID NO: 74. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-L1 having the amino acid sequence of SEQ ID NO: 75, CDR-L2 having the amino acid sequence of SEQ ID NO: 45, and CDR-L3 having the amino acid sequence of SEQ ID NO: 88.

[0228] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 72; CDR-H2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 87; and / or (e.g., and) CDR-H3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 74. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: CDR-L1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 75; CDR-L2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 45; and / or (e.g., and) CDR-L3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 88.

[0229] In some embodiments, the anti-TfR antibody of this disclosure comprises a VH containing the amino acid sequence of SEQ ID NO: 89. Alternatively or as an alternative (e.g., supplement), the anti-TfR antibody of this disclosure comprises a VL containing the amino acid sequence of SEQ ID NO: 90.

[0230] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, which contains no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation) compared to the VH shown in SEQ ID NO: 89. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a VL containing no more than 25 amino acid variations compared to the VL shown in SEQ ID NO: 90 (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation).

[0231] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, said VH containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VH shown in SEQ ID NO:89. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises VL, said VL containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in SEQ ID NO:90.

[0232] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which are heavy chain variable domains having the amino acid sequence of SEQ ID NO: 97. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which are light chain variable domains having the amino acid sequence of SEQ ID NO: 98.

[0233] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 91, CDR-H2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 92, CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 93, CDR-L1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 94, CDR-L2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 95, and CDR-L3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 96.

[0234] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which, compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 91, CDR-H2 having the amino acid sequence of SEQ ID NO: 92, and CDR-H3 having the amino acid sequence of SEQ ID NO: 93, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation). Alternatively or supplementally (e.g., as a supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which, compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 94, CDR-L2 having the amino acid sequence of SEQ ID NO: 95, and CDR-L3 having the amino acid sequence of SEQ ID NO: 96, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation).

[0235] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-H1 having the amino acid sequence of SEQ ID NO: 91, CDR-H2 having the amino acid sequence of SEQ ID NO: 92, and CDR-H3 having the amino acid sequence of SEQ ID NO: 93. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-L1 having the amino acid sequence of SEQ ID NO: 94, CDR-L2 having the amino acid sequence of SEQ ID NO: 95, and CDR-L3 having the amino acid sequence of SEQ ID NO: 96.

[0236] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 91; CDR-H2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 92; and / or (e.g., and) CDR-H3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 93. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: CDR-L1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 94; CDR-L2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 95; and / or (e.g., and) CDR-L3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 96.

[0237] In some embodiments, the anti-TfR antibody of this disclosure comprises a VH containing the amino acid sequence of SEQ ID NO: 97. Alternatively or as an alternative (e.g., supplement), the anti-TfR antibody of this disclosure comprises a VL containing the amino acid sequence of SEQ ID NO: 98.

[0238] In some embodiments, the anti-TfR antibody of this disclosure comprises a VH containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH shown in SEQ ID NO: 98. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises a VL containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VL shown in SEQ ID NO: 98.

[0239] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, said VH containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VH shown in SEQ ID NO:97. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises VL, said VL containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in SEQ ID NO:98.

[0240] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which are heavy chain variable domains having the amino acid sequence of SEQ ID NO: 104. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which are light chain variable domains having the amino acid sequence of SEQ ID NO: 105.

[0241] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which, compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 99, CDR-H2 having the amino acid sequence of SEQ ID NO: 100, and CDR-H3 having the amino acid sequence of SEQ ID NO: 101, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation). Alternatively or supplementally (e.g., as a supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which, compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 102, CDR-L2 having the amino acid sequence of SEQ ID NO: 60, and CDR-L3 having the amino acid sequence of SEQ ID NO: 103, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation).

[0242] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-H1 having the amino acid sequence of SEQ ID NO: 99, CDR-H2 having the amino acid sequence of SEQ ID NO: 100, and CDR-H3 having the amino acid sequence of SEQ ID NO: 101. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-L1 having the amino acid sequence of SEQ ID NO: 102, CDR-L2 having the amino acid sequence of SEQ ID NO: 60, and CDR-L3 having the amino acid sequence of SEQ ID NO: 103.

[0243] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 99; CDR-H2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 100; and / or (e.g., and) CDR-H3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 101. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: CDR-L1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 102; CDR-L2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 60; and / or (e.g., and) CDR-L3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 103.

[0244] In some embodiments, the anti-TfR antibody of this disclosure comprises a VH containing the amino acid sequence of SEQ ID NO: 104. Alternatively or as an alternative (e.g., supplement), the anti-TfR antibody of this disclosure comprises a VL containing the amino acid sequence of SEQ ID NO: 105.

[0245] In some embodiments, the anti-TfR antibody of this disclosure comprises a VH containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH shown in SEQ ID NO: 105. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises a VL containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VL shown in SEQ ID NO: 105.

[0246] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, said VH containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VH shown in SEQ ID NO: 104. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises VL, said VL containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in SEQ ID NO: 105.

[0247] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which are heavy chain variable domains having the amino acid sequence of SEQ ID NO: 112. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which are light chain variable domains having the amino acid sequence of SEQ ID NO: 113.

[0248] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 106, CDR-H2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 107, CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 108, CDR-L1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 109, CDR-L2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 110, and CDR-L3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 111.

[0249] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which, compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 106, CDR-H2 having the amino acid sequence of SEQ ID NO: 107, and CDR-H3 having the amino acid sequence of SEQ ID NO: 108, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation). Alternatively or supplementally (e.g., as a supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which, compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 109, CDR-L2 having the amino acid sequence of SEQ ID NO: 110, and CDR-L3 having the amino acid sequence of SEQ ID NO: 111, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation).

[0250] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-H1 having the amino acid sequence of SEQ ID NO: 106, CDR-H2 having the amino acid sequence of SEQ ID NO: 107, and CDR-H3 having the amino acid sequence of SEQ ID NO: 108. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-L1 having the amino acid sequence of SEQ ID NO: 109, CDR-L2 having the amino acid sequence of SEQ ID NO: 110, and CDR-L3 having the amino acid sequence of SEQ ID NO: 111.

[0251] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 106; CDR-H2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 107; and / or (e.g., and) CDR-H3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 108. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: CDR-L1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 109; CDR-L2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 110; and / or (e.g., and) CDR-L3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 111.

[0252] In some embodiments, the anti-TfR antibody of this disclosure comprises a VH containing the amino acid sequence of SEQ ID NO: 112. Alternatively or as an alternative (e.g., supplement), the anti-TfR antibody of this disclosure comprises a VL containing the amino acid sequence of SEQ ID NO: 113.

[0253] In some embodiments, the anti-TfR antibody of this disclosure comprises a VH containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH shown in SEQ ID NO: 113. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises a VL containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VL shown in SEQ ID NO: 113.

[0254] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, said VH containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VH shown in SEQ ID NO: 112. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises VL, said VL containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in SEQ ID NO: 113.

[0255] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which are heavy chain variable domains having the amino acid sequence of SEQ ID NO: 117. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which are light chain variable domains having the amino acid sequence of SEQ ID NO: 118.

[0256] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 79, CDR-H2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 114, CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 115, CDR-L1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 82, CDR-L2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 83, and CDR-L3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 116.

[0257] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which, compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 79, CDR-H2 having the amino acid sequence of SEQ ID NO: 114, and CDR-H3 having the amino acid sequence of SEQ ID NO: 115, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation). Alternatively or supplementally (e.g., as a supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which, compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 82, CDR-L2 having the amino acid sequence of SEQ ID NO: 83, and CDR-L3 having the amino acid sequence of SEQ ID NO: 116, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation).

[0258] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-H1 having the amino acid sequence of SEQ ID NO: 79, CDR-H2 having the amino acid sequence of SEQ ID NO: 114, and CDR-H3 having the amino acid sequence of SEQ ID NO: 115. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-L1 having the amino acid sequence of SEQ ID NO: 82, CDR-L2 having the amino acid sequence of SEQ ID NO: 83, and CDR-L3 having the amino acid sequence of SEQ ID NO: 116.

[0259] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 79; CDR-H2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 114; and / or (e.g., and) CDR-H3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 115. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: CDR-L1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 82; CDR-L2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 83; and / or (e.g., and) CDR-L3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 116.

[0260] In some embodiments, the anti-TfR antibody of this disclosure comprises a VH containing the amino acid sequence of SEQ ID NO: 117. Alternatively or as an alternative (e.g., supplement), the anti-TfR antibody of this disclosure comprises a VL containing the amino acid sequence of SEQ ID NO: 118.

[0261] In some embodiments, the anti-TfR antibody of this disclosure comprises a VH containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH shown in SEQ ID NO: 118. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises a VL containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VL shown in SEQ ID NO: 118.

[0262] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, said VH containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VH shown in SEQ ID NO: 117. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises VL, said VL containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in SEQ ID NO: 118.

[0263] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which are heavy chain variable domains having the amino acid sequence of SEQ ID NO: 124. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which are light chain variable domains having the amino acid sequence of SEQ ID NO: 125.

[0264] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 119, CDR-H2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 120, CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 121, CDR-L1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 122, CDR-L2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 45, and CDR-L3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 123.

[0265] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which, compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 119, CDR-H2 having the amino acid sequence of SEQ ID NO: 120, and CDR-H3 having the amino acid sequence of SEQ ID NO: 121, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation). Alternatively or supplementally (e.g., as a supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which, compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 122, CDR-L2 having the amino acid sequence of SEQ ID NO: 45, and CDR-L3 having the amino acid sequence of SEQ ID NO: 123, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation).

[0266] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-H1 having the amino acid sequence of SEQ ID NO: 119, CDR-H2 having the amino acid sequence of SEQ ID NO: 120, and CDR-H3 having the amino acid sequence of SEQ ID NO: 121. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-L1 having the amino acid sequence of SEQ ID NO: 122, CDR-L2 having the amino acid sequence of SEQ ID NO: 45, and CDR-L3 having the amino acid sequence of SEQ ID NO: 123.

[0267] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 119; CDR-H2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 120; and / or (e.g., and) CDR-H3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 121. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: CDR-L1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 122; CDR-L2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 45; and / or (e.g., and) CDR-L3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 123.

[0268] In some embodiments, the anti-TfR antibody of this disclosure comprises a VH containing the amino acid sequence of SEQ ID NO: 124. Alternatively or as a supplement (e.g., an alternative), the anti-TfR antibody of this disclosure comprises a VL containing the amino acid sequence of SEQ ID NO: 125.

[0269] In some embodiments, the anti-TfR antibody of this disclosure comprises a VH containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH shown in SEQ ID NO: 125. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises a VL containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VL shown in SEQ ID NO: 125.

[0270] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, said VH containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VH shown in SEQ ID NO: 124. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises VL, said VL containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in SEQ ID NO: 125.

[0271] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which are heavy chain variable domains having the amino acid sequence of SEQ ID NO: 132. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which are light chain variable domains having the amino acid sequence of SEQ ID NO: 133.

[0272] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 126, CDR-H2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 127, CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 128, CDR-L1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 129, CDR-L2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 130, and CDR-L3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 131.

[0273] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which, compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 126, CDR-H2 having the amino acid sequence of SEQ ID NO: 127, and CDR-H3 having the amino acid sequence of SEQ ID NO: 128, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation). Alternatively or supplementally (e.g., as a supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which, compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 129, CDR-L2 having the amino acid sequence of SEQ ID NO: 130, and CDR-L3 having the amino acid sequence of SEQ ID NO: 131, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation).

[0274] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-H1 having the amino acid sequence of SEQ ID NO: 126, CDR-H2 having the amino acid sequence of SEQ ID NO: 127, and CDR-H3 having the amino acid sequence of SEQ ID NO: 128. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-L1 having the amino acid sequence of SEQ ID NO: 129, CDR-L2 having the amino acid sequence of SEQ ID NO: 130, and CDR-L3 having the amino acid sequence of SEQ ID NO: 131.

[0275] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 126; CDR-H2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 127; and / or (e.g., and) CDR-H3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 128. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: CDR-L1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 129; CDR-L2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 130; and / or (e.g., and) CDR-L3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 131.

[0276] In some embodiments, the anti-TfR antibody of this disclosure comprises a VH containing the amino acid sequence of SEQ ID NO: 132. Alternatively or as an alternative (e.g., supplement), the anti-TfR antibody of this disclosure comprises a VL containing the amino acid sequence of SEQ ID NO: 133.

[0277] In some embodiments, the anti-TfR antibody of this disclosure comprises a VH containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH shown in SEQ ID NO: 133. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises a VL containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VL shown in SEQ ID NO: 133.

[0278] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, said VH containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VH shown in SEQ ID NO: 132. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises VL, said VL containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in SEQ ID NO: 133.

[0279] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which are heavy chain variable domains having the amino acid sequence of SEQ ID NO: 136. Alternatively or supplementally (e.g., additionally), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which are light chain variable domains having the amino acid sequence of SEQ ID NO: 137.

[0280] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 79, CDR-H2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 2, CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 134, CDR-L1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 75, CDR-L2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 45, and CDR-L3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 135.

[0281] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which, compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 79, CDR-H2 having the amino acid sequence of SEQ ID NO: 2, and CDR-H3 having the amino acid sequence of SEQ ID NO: 134, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation). Alternatively or supplementally (e.g., as a supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which, compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 75, CDR-L2 having the amino acid sequence of SEQ ID NO: 45, and CDR-L3 having the amino acid sequence of SEQ ID NO: 135, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation).

[0282] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-H1 having the amino acid sequence of SEQ ID NO: 79, CDR-H2 having the amino acid sequence of SEQ ID NO: 2, and CDR-H3 having the amino acid sequence of SEQ ID NO: 134. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-L1 having the amino acid sequence of SEQ ID NO: 75, CDR-L2 having the amino acid sequence of SEQ ID NO: 45, and CDR-L3 having the amino acid sequence of SEQ ID NO: 135.

[0283] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 79; CDR-H2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 2; and / or (e.g., and) CDR-H3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 134. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: CDR-L1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 75; CDR-L2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 45; and / or (e.g., and) CDR-L3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 135.

[0284] In some embodiments, the anti-TfR antibody of this disclosure comprises a VH containing the amino acid sequence of SEQ ID NO: 136. Alternatively or as an alternative (e.g., supplement), the anti-TfR antibody of this disclosure comprises a VL containing the amino acid sequence of SEQ ID NO: 137.

[0285] In some embodiments, the anti-TfR antibody of this disclosure comprises a VH containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH shown in SEQ ID NO: 137. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises a VL containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VL shown in SEQ ID NO: 137.

[0286] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, said VH containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VH shown in SEQ ID NO: 136. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises VL, said VL containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in SEQ ID NO: 137.

[0287] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which are heavy chain variable domains having the amino acid sequence of SEQ ID NO: 143. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which are light chain variable domains having the amino acid sequence of SEQ ID NO: 144.

[0288] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 138, CDR-H2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 139, CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 140, CDR-L1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 141, CDR-L2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 29, and CDR-L3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 142.

[0289] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which, compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 138, CDR-H2 having the amino acid sequence of SEQ ID NO: 139, and CDR-H3 having the amino acid sequence of SEQ ID NO: 140, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation). Alternatively or supplementally (e.g., as a supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which, compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 141, CDR-L2 having the amino acid sequence of SEQ ID NO: 29, and CDR-L3 having the amino acid sequence of SEQ ID NO: 142, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation).

[0290] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-H1 having the amino acid sequence of SEQ ID NO: 138, CDR-H2 having the amino acid sequence of SEQ ID NO: 139, and CDR-H3 having the amino acid sequence of SEQ ID NO: 140. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-L1 having the amino acid sequence of SEQ ID NO: 141, CDR-L2 having the amino acid sequence of SEQ ID NO: 29, and CDR-L3 having the amino acid sequence of SEQ ID NO: 142.

[0291] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 138; CDR-H2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 139; and / or (e.g., and) CDR-H3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 140. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: CDR-L1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 141; CDR-L2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 29; and / or (e.g., and) CDR-L3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 142.

[0292] In some embodiments, the anti-TfR antibody of this disclosure comprises a VH containing the amino acid sequence of SEQ ID NO: 143. Alternatively or as an alternative (e.g., supplement), the anti-TfR antibody of this disclosure comprises a VL containing the amino acid sequence of SEQ ID NO: 144.

[0293] In some embodiments, the anti-TfR antibody of this disclosure comprises a VH containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH shown in SEQ ID NO: 144. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises a VL containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VL shown in SEQ ID NO: 144.

[0294] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, said VH containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VH shown in SEQ ID NO: 143. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises VL, said VL containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in SEQ ID NO: 144.

[0295] When different definition systems (e.g., IMGT definition, Kabat definition, or Chothia definition) are used, the CDR of an antibody may have different amino acid sequences. Definition systems annotate each amino acid in a given antibody sequence (e.g., VH or VL sequence) with numbers, and Table 3 provides the numbers corresponding to the heavy chain CDR and light chain CDR. The CDRs listed in Table 2 are defined according to the IMGT definition. Table 4 provides CDR sequences for some examples of anti-TfR antibodies according to different definition systems. Those skilled in the art can deduce the CDR sequences of the anti-TfR antibodies provided in Table 2 using different numbering systems.

[0296] Table 3. CDR Limitations

[0297]

[0298] 1 IMGT ® , the international ImMunoGeneTics information system ® ,imgt.org, Lefranc, M.-P. et al., Nucleic Acids Res., 27:209-212 (1999)

[0299] 2 Kabat et al. (1991) Sequences of Proteins of ImmunologicalInterest, Fifth Edition, US Department of Health and Human Services, NIHPublication No. 91-3242

[0300] 3Chothia et al., J. Mol. Biol. 196:901-917 (1987))

[0301] Table 4. CDR sequences of some examples of anti-TfR antibodies according to different definition systems.

[0302]

[0303]

[0304]

[0305] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 145, CDR-H2 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 146, SEQ ID NO: 267 or SEQ ID NO: 269, CDR-H3 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 147, CDR-L1 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 148, CDR-L2 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 149, and CDR-L3 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 6.

[0306] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which, together with CDR-H1 having the amino acid sequence of SEQ ID NO: 145, CDR-H2 having the amino acid sequence of SEQ ID NO: 146, SEQ ID NO: 267, or SEQ ID NO: 269, and CDR-H3 having the amino acid sequence of SEQ ID NO: 147, comprise no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation). As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 148, CDR-L2 having the amino acid sequence of SEQ ID NO: 149, and CDR-L3 having the amino acid sequence of SEQ ID NO: 6.

[0307] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which together share at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-H1 having the amino acid sequence of SEQ ID NO: 145, CDR-H2 having the amino acid sequence of SEQ ID NO: 146, SEQ ID NO: 267, or SEQ ID NO: 269, and CDR-H3 having the amino acid sequence of SEQ ID NO: 147. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-L1 having the amino acid sequence of SEQ ID NO: 148, CDR-L2 having the amino acid sequence of SEQ ID NO: 149, and CDR-L3 having the amino acid sequence of SEQ ID NO: 6.

[0308] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 145; CDR-H2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 146, SEQ ID NO: 267, or SEQ ID NO: 269; and / or (e.g., and) CDR-H3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 147. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: CDR-L1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 148; CDR-L2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 149; and / or (e.g., and) CDR-L3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 6.

[0309] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 150, CDR-H2 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 151, SEQ ID NO: 274 or SEQ ID NO: 275, CDR-H3 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 152, CDR-L1 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 153, CDR-L2 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 5, and CDR-L3 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 154.

[0310] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which, together with CDR-H1 having the amino acid sequence of SEQ ID NO: 150, CDR-H2 having the amino acid sequence of SEQ ID NO: 151, SEQ ID NO: 274, or SEQ ID NO: 275, and CDR-H3 having the amino acid sequence of SEQ ID NO: 152, comprise no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation). As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 153, CDR-L2 having the amino acid sequence of SEQ ID NO: 5, and CDR-L3 having the amino acid sequence of SEQ ID NO: 154.

[0311] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which together share at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-H1 having the amino acid sequence of SEQ ID NO: 150, CDR-H2 having the amino acid sequence of SEQ ID NO: 151, SEQ ID NO: 274, or SEQ ID NO: 275, and CDR-H3 having the amino acid sequence of SEQ ID NO: 152. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-L1 having the amino acid sequence of SEQ ID NO: 153, CDR-L2 having the amino acid sequence of SEQ ID NO: 5, and CDR-L3 having the amino acid sequence of SEQ ID NO: 154.

[0312] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 150; CDR-H2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 151, SEQ ID NO: 274, or SEQ ID NO: 275; and / or (e.g., and) CDR-H3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 152. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: a CDR-L1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to a CDR-L1 having the amino acid sequence of SEQ ID NO: 153; a CDR-L2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to a CDR-L2 having the amino acid sequence of SEQ ID NO: 5; and / or (e.g., and) a CDR-L3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to a CDR-L3 having the amino acid sequence of SEQ ID NO: 154.

[0313] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 155, CDR-H2 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 156, CDR-H3 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 157, CDR-L1 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 158, CDR-L2 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 159, and CDR-L3 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 14.

[0314] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which, compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 155, CDR-H2 having the amino acid sequence of SEQ ID NO: 156, and CDR-H3 having the amino acid sequence of SEQ ID NO: 157, collectively comprise no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation). Alternatively or supplementally (e.g., as a supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which, compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 158, CDR-L2 having the amino acid sequence of SEQ ID NO: 159, and CDR-L3 having the amino acid sequence of SEQ ID NO: 14, collectively comprise no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation).

[0315] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-H1 having the amino acid sequence of SEQ ID NO: 155, CDR-H2 having the amino acid sequence of SEQ ID NO: 156, and CDR-H3 having the amino acid sequence of SEQ ID NO: 157. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-L1 having the amino acid sequence of SEQ ID NO: 158, CDR-L2 having the amino acid sequence of SEQ ID NO: 159, and CDR-L3 having the amino acid sequence of SEQ ID NO: 14.

[0316] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 155; CDR-H2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 156; and / or (e.g., and) CDR-H3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 157. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: CDR-L1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 158; CDR-L2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 159; and / or (e.g., and) CDR-L3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 14.

[0317] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 160, CDR-H2 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 161, CDR-H3 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 162, CDR-L1 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 163, CDR-L2 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 13, and CDR-L3 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 164.

[0318] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which, compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 160, CDR-H2 having the amino acid sequence of SEQ ID NO: 161, and CDR-H3 having the amino acid sequence of SEQ ID NO: 162, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation). Alternatively or supplementally (e.g., as a supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which, compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 163, CDR-L2 having the amino acid sequence of SEQ ID NO: 13, and CDR-L3 having the amino acid sequence of SEQ ID NO: 164, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation).

[0319] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-H1 having the amino acid sequence of SEQ ID NO: 160, CDR-H2 having the amino acid sequence of SEQ ID NO: 161, and CDR-H3 having the amino acid sequence of SEQ ID NO: 162. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-L1 having the amino acid sequence of SEQ ID NO: 163, CDR-L2 having the amino acid sequence of SEQ ID NO: 13, and CDR-L3 having the amino acid sequence of SEQ ID NO: 164.

[0320] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 160; CDR-H2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 161; and / or (e.g., and) CDR-H3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 162. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: CDR-L1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 163; CDR-L2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 13; and / or (e.g., and) CDR-L3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 164.

[0321] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 165, SEQ ID NO: 271 or SEQ ID NO: 273, CDR-H2 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 166, CDR-H3 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 167, CDR-L1 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 168, CDR-L2 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 169 and CDR-L3 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 22.

[0322] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which, together with CDR-H1 having the amino acid sequence of SEQ ID NO: 165, SEQ ID NO: 271, or SEQ ID NO: 273, CDR-H2 having the amino acid sequence of SEQ ID NO: 166, and CDR-H3 having the amino acid sequence of SEQ ID NO: 167, comprise no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation). As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 168, CDR-L2 having the amino acid sequence of SEQ ID NO: 169, and CDR-L3 having the amino acid sequence of SEQ ID NO: 22.

[0323] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-H1 having the amino acid sequence of SEQ ID NO: 165, SEQ ID NO: 271, or SEQ ID NO: 273, CDR-H2 having the amino acid sequence of SEQ ID NO: 166, and CDR-H3 having the amino acid sequence of SEQ ID NO: 167. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-L1 having the amino acid sequence of SEQ ID NO: 168, CDR-L2 having the amino acid sequence of SEQ ID NO: 169, and CDR-L3 having the amino acid sequence of SEQ ID NO: 22.

[0324] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 165, SEQ ID NO: 271, or SEQ ID NO: 273; CDR-H2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 166; and / or (e.g., and) CDR-H3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 167. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: CDR-L1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 168; CDR-L2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 169; and / or (e.g., and) CDR-L3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 22.

[0325] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 170, CDR-H2 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 171, CDR-H3 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 172, CDR-L1 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 173, CDR-L2 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 21, and CDR-L3 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 174.

[0326] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which, compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 170, CDR-H2 having the amino acid sequence of SEQ ID NO: 171, and CDR-H3 having the amino acid sequence of SEQ ID NO: 172, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation). Alternatively or supplementally (e.g., as a supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which, compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 173, CDR-L2 having the amino acid sequence of SEQ ID NO: 21, and CDR-L3 having the amino acid sequence of SEQ ID NO: 174, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation).

[0327] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-H1 having the amino acid sequence of SEQ ID NO: 170, CDR-H2 having the amino acid sequence of SEQ ID NO: 171, and CDR-H3 having the amino acid sequence of SEQ ID NO: 172. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-L1 having the amino acid sequence of SEQ ID NO: 173, CDR-L2 having the amino acid sequence of SEQ ID NO: 21, and CDR-L3 having the amino acid sequence of SEQ ID NO: 174.

[0328] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 170; CDR-H2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 171; and / or (e.g., and) CDR-H3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 172. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: CDR-L1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 173; CDR-L2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 21; and / or (e.g., and) CDR-L3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 174.

[0329] In some embodiments, the anti-TfR antibody of this disclosure is a humanized antibody (e.g., containing a humanized variant of one or more CDRs from Table 2 or Table 4). In some embodiments, the anti-TfR antibody of this disclosure contains the same CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2, and CDR-L3 as CDR-H1, CDR-H2, and CDR-H3 shown in Table 2 or Table 4, and contains a humanized heavy chain variable region and / or (e.g., and) a humanized light chain variable region.

[0330] Humanized antibodies are human immunoglobulins (receptor antibodies) in which residues from the complementary determining region (CDR) of the receptor are replaced by residues from the CDR of a non-human species (donor antibody) with the desired specificity, affinity, and capacity, such as mouse, rat, or rabbit. In some embodiments, Fv framework region (FR) residues of the human immunoglobulin are replaced by corresponding non-human residues. Furthermore, humanized antibodies may include residues not found in either the receptor antibody or the introduced CDR or framework sequence but included to further refine and optimize antibody performance. Generally, humanized antibodies will contain substantially all of at least one, and typically two, variable domains, wherein all or substantially all of the CDR regions correspond to those of non-human immunoglobulins, and all or substantially all of the FR regions are those of human immunoglobulin common sequences. Humanized antibodies will also preferably also contain at least a portion of the immunoglobulin constant region or Fc domain (typically those of human immunoglobulins). Antibodies may have an Fc region modified as described in WO 99 / 58572. Other forms of humanized antibodies have one or more CDRs (one, two, three, four, five, or six) altered relative to the original antibody, also referred to as one or more CDRs derived from one or more CDRs of the original antibody. Humanized antibodies may also involve affinity maturation.

[0331] Humanized antibodies and their preparation methods are known, for example, as described in the following: Almagro et al., Front. Biosci. 13:1619-1633 (2008); Riechmann et al., Nature 332:323-329 (1988); Queen et al., Proc. Nat'l Acad. Sci. USA 86:10029-10033 (1989); U.S. Patent Nos. 5,821,337, 7,527,791, 6,982,321, and 7,087,409; Kashmiri et al., Methods 36:25-34 (2005); Padlan et al., Mol. Immunol. 28:489-498 (1991); Dall'Acqua et al., Methods 36:43-60 (2005); Osbourn et al., Methods 36:61-68 (2005); and Klimka et al., Br. J. Cancer, 83:252-260 (2000), all of which are incorporated herein by reference. Human framework regions available for humanization are described, for example, in: Sims et al. J. Immunol. 151:2296 (1993); Carter et al. Proc. Natl. Acad. Sci. USA, 89:4285 (1992); Presta et al. J. Immunol., 151:2623 (1993); Almagro et al., Front. Biosci. 13:1619-1633 (2008); Baca et al., J. Biol. Chem. 272:10678-10684 (1997); and Rosok et al., JBiol. Chem. 271:22611-22618 (1996), all of which are incorporated herein by reference. In some implementations, humanization is achieved by grafting CDRs (e.g., as shown in Table 2 or Table 4) into the human variable structural domains of IGKV1-NL1*01 and IGHV1-3*01.

[0332] In some implementations, the humanized VH framework or the humanized VL framework is a common human framework. In some implementations, the common humanized framework may represent the most common amino acid residues when selecting the human immunoglobulin VL or VH framework sequence.

[0333] In some implementations, the shared human VH framework region suitable for use with the heavy chain CDR in the humanized anti-TfR antibody described herein includes (subgroup III shared):

[0334] a) VH FR1: ;

[0335] b) VH FR2: ;

[0336] c) VH FR3: ;and

[0337] d) VH FR4: .

[0338] In some implementations, the shared human VH framework region suitable for use with the heavy chain CDR in the humanized anti-TfR antibody described herein includes (subgroup I shared):

[0339] a) VH FR1: ;

[0340] b) VH FR2: ;

[0341] c) VH FR3: ;and

[0342] d) VH FR4: .

[0343] In some implementations, the shared human VH framework region suitable for use with the heavy chain CDR in the humanized anti-TfR antibody described herein includes (subgroup II shared):

[0344] a) VH FR1: ;

[0345] b) VH FR2: ;

[0346] c) VH FR3: ;and

[0347] d) VH FR4: .

[0348] In some implementations, the shared human VL framework region suitable for use with the light chain CDR in the humanized anti-TfR antibody described herein includes (subgroup I shared):

[0349] a) VL FR1: ;

[0350] b) VL FR2: ;

[0351] c) VL FR3: ;and

[0352] d) VL FR4: .

[0353] In some implementations, the shared human VL framework region suitable for use with the light chain CDR in the humanized anti-TfR antibody described herein includes (subgroup II shared):

[0354] a) VL FR1: ;

[0355] b) VL FR2: ;

[0356] c) VL FR3: ;and

[0357] d) VL FR4: .

[0358] In some implementations, the shared human VL framework region suitable for use with the light chain CDR in the humanized anti-TfR antibody described herein includes (subgroup III shared):

[0359] a) VL FR1: ;

[0360] b) VL FR2: ;

[0361] c) VL FR3: ;and

[0362] d) VL FR4: .

[0363] In some implementations, the shared human VL framework region suitable for use with the light chain CDR in the humanized anti-TfR antibody described herein includes (subgroup IV shared):

[0364] a) VL FR1: ;

[0365] b) VL FR2: ;

[0366] c) VL FR3: ;and

[0367] d) VL FR4: .

[0368] In some embodiments, the humanized anti-TfR antibody of this disclosure comprises a humanized VH framework region that, compared with any common human VH framework region subgroup described herein, contains no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation). As an alternative or supplement (e.g., supplement), the humanized anti-TfR antibody of this disclosure comprises a humanized VL frame region that, compared with any common human VL frame region subgroup described herein, contains no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation).

[0369] In some embodiments, the humanized anti-TfR antibody of this disclosure comprises a humanized VH frame region that shares at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with any of the common human VH frame region subgroups described herein. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises a humanized VL frame region that shares at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with any of the common human VL frame region subgroups described herein.

[0370] In some embodiments, the anti-TfR antibody of this disclosure is a humanized variant that contains one or more amino acid variations (e.g., in the VH frame region) compared to any of the VHs listed in Table 2 or Table 4; and / or (e.g., and) contains one or more amino acid variations (e.g., in the VL frame region) compared to any of the VLs listed in Table 2 or Table 4.

[0371] In some embodiments, the anti-TfR antibody of this disclosure is a humanized antibody containing a VH, which, compared to the VH of any of the anti-TfR antibodies listed in Table 2, contains no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation). As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure is a humanized antibody containing a VL, which, compared to the VL of any anti-TfR antibody listed in Table 2, contains no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation).

[0372] In some embodiments, the anti-TfR antibody of this disclosure is a humanized antibody comprising a VH, said VH comprising an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VH shown in any one of SEQ ID NOs: 7, 15, and 23. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure is a humanized antibody comprising a VL, said VL comprising an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in any one of SEQ ID NOs: 8, 16, and 24.

[0373] In some embodiments, the anti-TfR antibody of this disclosure is a humanized antibody containing a VH, wherein the VH contains no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation) compared to the VH shown in any of SEQ ID NO: 7, 15 and 23. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure is a humanized antibody containing a VL, which, compared to the VL shown in any one of SEQ ID NO: 8, 16 and 24, contains no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation).

[0374] In some embodiments, the anti-TfR antibody of this disclosure is a humanized antibody comprising a VH, said VH comprising an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VH shown in any one of SEQ ID NOs: 7, 15, and 23. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure is a humanized antibody comprising a VL, said VL comprising an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in any one of SEQ ID NOs: 8, 16, and 24.

[0375] In some embodiments, the anti-TfR antibody of this disclosure is a humanized antibody containing VH, said VH having one or more (e.g., 10 to 25) amino acid variations at positions 1, 2, 5, 9, 11, 12, 13, 17, 20, 23, 33, 38, 40, 41, 42, 43, 44, 45, 48, 49, 55, 67, 68, 70, 71, 72, 76, 77, 80, 81, 82, 84, 87, 88, 91, 95, 112, or 115 relative to the VH shown in any of SEQ ID NO: 7, 15, and 23. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure is a humanized antibody comprising a VL having one or more (e.g., 10 to 20) amino acid variations at positions 4, 7, 8, 9, 11, 15, 17, 18, 19, 22, 39, 41, 42, 43, 50, 62, 64, 72, 75, 77, 79, 80, 81, 82, 83, 85, 87, 89, 100, 104, or 109 relative to the VL shown in any of SEQ ID NO: 8, 16, and 24.

[0376] In some embodiments, the anti-TfR antibody of this disclosure comprises a humanized VH, said humanized VH comprising CDR-H1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 1, CDR-H2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 2, SEQ ID NO: 266 or SEQ ID NO: 80, CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 3, and containing no more than 25 amino acid variations in the frame region compared to the VH shown in SEQ ID NO: 7 (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation). As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a humanized VL, which comprises CDR-L1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 4, CDR-L2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 5, and CDR-L3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 6, and contains no more than 25 amino acid variations in the frame region compared to the VL shown in SEQ ID NO: 8 (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation).

[0377] In some embodiments, the anti-TfR antibody of this disclosure comprises a humanized VH, said humanized VH comprising CDR-H1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 1, CDR-H2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 2, SEQ ID NO: 266 or SEQ ID NO: 80, CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 3, and having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98% or 99%) identity with the VH shown in SEQ ID NO: 7 in the frame region. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a humanized VL comprising CDR-L1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 4, CDR-L2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 5, and CDR-L3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 6, and having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in SEQ ID NO: 8 in the frame region.

[0378] In some embodiments, the anti-TfR antibody of this disclosure comprises a humanized VH, said humanized VH comprising CDR-H1 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 145, CDR-H2 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 146, SEQ ID NO: 267 or SEQ ID NO: 269, CDR-H3 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 147, and containing no more than 25 amino acid variations in the frame region compared to the VH shown in SEQ ID NO: 7 (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation). As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a humanized VL, which comprises CDR-L1 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 148, CDR-L2 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 149, and CDR-L3 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 6, and contains no more than 25 amino acid variations in the frame region compared to the VL shown in SEQ ID NO: 8 (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation).

[0379] In some embodiments, the anti-TfR antibody of this disclosure comprises a humanized VH comprising CDR-H1 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 145, CDR-H2 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 146, SEQ ID NO: 267 or SEQ ID NO: 269, and CDR-H3 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 147, and having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98% or 99%) identity with the VH shown in SEQ ID NO: 7 in the frame region. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a humanized VL comprising CDR-L1 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 148, CDR-L2 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 149, and CDR-L3 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 6, and having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in SEQ ID NO: 8 in the frame region.

[0380] In some embodiments, the anti-TfR antibody of this disclosure comprises a humanized VH, said humanized VH comprising CDR-H1 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 150, CDR-H2 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 151, SEQ ID NO: 274 or SEQ ID NO: 275, CDR-H3 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 152, and containing no more than 25 amino acid variations in the frame region compared to the VH shown in SEQ ID NO: 7 (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation). As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a humanized VL comprising CDR-L1 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 153, CDR-L2 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 5, and CDR-L3 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 154, and comprising no more than 25 amino acid variations in the frame region (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VL shown in SEQ ID NO: 8.

[0381] In some embodiments, the anti-TfR antibody of this disclosure comprises a humanized VH comprising CDR-H1 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 150, CDR-H2 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 151, SEQ ID NO: 274 or SEQ ID NO: 275, CDR-H3 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 152, and having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98% or 99%) identity with the VH shown in SEQ ID NO: 7 in the frame region. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a humanized VL comprising CDR-L1 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 153, CDR-L2 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 5, and CDR-L3 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 154, and having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in SEQ ID NO: 8 in the frame region.

[0382] In some embodiments, the anti-TfR antibody of this disclosure comprises a humanized VH, said humanized VH comprising CDR-H1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 9, CDR-H2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 10, CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 11, and containing no more than 25 amino acid variations in the frame region compared to the VH shown in SEQ ID NO: 15 (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation). As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a humanized VL comprising CDR-L1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 12, CDR-L2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 13, and CDR-L3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 14, and comprising no more than 25 amino acid variations in the frame region compared to the VL shown in SEQ ID NO: 16 (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation).

[0383] In some embodiments, the anti-TfR antibody of this disclosure comprises a humanized VH, said humanized VH comprising CDR-H1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 9, CDR-H2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 10, and CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 11, and having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VH shown in SEQ ID NO: 15 in the frame region. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a humanized VL comprising CDR-L1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 12, CDR-L2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 13, and CDR-L3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 14, and having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in SEQ ID NO: 16 in the frame region.

[0384] In some embodiments, the anti-TfR antibody of this disclosure comprises a humanized VH, said humanized VH comprising CDR-H1 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 155, CDR-H2 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 156, CDR-H3 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 157, and containing no more than 25 amino acid variations in the frame region compared to the VH shown in SEQ ID NO: 15 (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation). As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a humanized VL comprising CDR-L1 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 158, CDR-L2 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 159, and CDR-L3 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 14, and containing no more than 25 amino acid variations in the frame region compared to the VL shown in SEQ ID NO: 16 (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation).

[0385] In some embodiments, the anti-TfR antibody of this disclosure comprises a humanized VH, said humanized VH comprising CDR-H1 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 155, CDR-H2 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 156, and CDR-H3 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 157, and having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VH shown in SEQ ID NO: 15 in the frame region. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a humanized VL comprising CDR-L1 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 158, CDR-L2 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 159, and CDR-L3 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 14, and having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in SEQ ID NO: 16 in the frame region.

[0386] In some embodiments, the anti-TfR antibody of this disclosure comprises a humanized VH, said humanized VH comprising CDR-H1 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 160, CDR-H2 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 161, CDR-H3 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 162, and containing no more than 25 amino acid variations in the frame region compared to the VH shown in SEQ ID NO: 15 (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation). As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a humanized VL comprising CDR-L1 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 163, CDR-L2 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 13, and CDR-L3 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 164, and comprising no more than 25 amino acid variations in the frame region compared to the VL shown in SEQ ID NO: 16 (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation).

[0387] In some embodiments, the anti-TfR antibody of this disclosure comprises a humanized VH, said humanized VH comprising CDR-H1 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 160, CDR-H2 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 161, and CDR-H3 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 162, and having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VH shown in SEQ ID NO: 15 in the frame region. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a humanized VL comprising CDR-L1 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 163, CDR-L2 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 13, and CDR-L3 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 164, and having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in SEQ ID NO: 16 in the frame region.

[0388] In some embodiments, the anti-TfR antibody of this disclosure comprises a humanized VH, said humanized VH comprising CDR-H1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 17, SEQ ID NO: 270 or SEQ ID NO: 272, CDR-H2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 18, CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 19, and containing no more than 25 amino acid variations in the frame region compared to the VH shown in SEQ ID NO: 23 (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation). As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a humanized VL, which comprises CDR-L1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 20, CDR-L2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 21, and CDR-L3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 22, and contains no more than 25 amino acid variations in the frame region compared to the VL shown in SEQ ID NO: 24 (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation).

[0389] In some embodiments, the anti-TfR antibody of this disclosure comprises a humanized VH, said humanized VH comprising CDR-H1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 17, SEQ ID NO: 270 or SEQ ID NO: 272, CDR-H2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 18, CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 19, and having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98% or 99%) identity with the VH shown in SEQ ID NO: 23 in the frame region. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a humanized VL comprising CDR-L1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 20, CDR-L2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 21, and CDR-L3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 22, and having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in SEQ ID NO: 24 in the frame region.

[0390] In some embodiments, the anti-TfR antibody of this disclosure comprises a humanized VH, said humanized VH comprising CDR-H1 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 165, SEQ ID NO: 271 or SEQ ID NO: 273, CDR-H2 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 166, CDR-H3 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 167, and containing no more than 25 amino acid variations in the frame region compared to the VH shown in SEQ ID NO: 23 (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation). As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a humanized VL comprising CDR-L1 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 168, CDR-L2 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 169, and CDR-L3 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 22, and containing no more than 25 amino acid variations in the frame region compared to the VL shown in SEQ ID NO: 24 (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation).

[0391] In some embodiments, the anti-TfR antibody of this disclosure comprises a humanized VH, said humanized VH comprising CDR-H1 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 165, SEQ ID NO: 271 or SEQ ID NO: 273, CDR-H2 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 166, CDR-H3 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 167, and having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98% or 99%) identity with the VH shown in SEQ ID NO: 23 in the frame region. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a humanized VL comprising CDR-L1 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 168, CDR-L2 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 169, and CDR-L3 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 22, and having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in SEQ ID NO: 24 in the frame region.

[0392] In some embodiments, the anti-TfR antibody of this disclosure comprises a humanized VH, said humanized VH comprising CDR-H1 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 170, CDR-H2 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 171, CDR-H3 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 172, and containing no more than 25 amino acid variations in the frame region compared to the VH shown in SEQ ID NO: 23 (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation). As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a humanized VL comprising CDR-L1 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 173, CDR-L2 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 21, and CDR-L3 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 174, and comprising no more than 25 amino acid variations in the frame region compared to the VL shown in SEQ ID NO: 24 (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation).

[0393] In some embodiments, the anti-TfR antibody of this disclosure comprises a humanized VH comprising CDR-H1 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 170, CDR-H2 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 171, and CDR-H3 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 172, and having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VH shown in SEQ ID NO: 23 in the frame region. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a humanized VL comprising CDR-L1 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 173, CDR-L2 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 21, and CDR-L3 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 174, and having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in SEQ ID NO: 24 in the frame region.

[0394] In some embodiments, the anti-TfR antibody of this disclosure is a chimeric antibody, which may comprise a heavy constant region and a light constant region derived from a human antibody. A chimeric antibody is an antibody having a variable region or a portion thereof derived from a first species and a constant region derived from a second species. Typically, in these chimeric antibodies, the variable regions of both the light and heavy chains mimic the variable regions derived from an antibody of one mammal (e.g., a non-human mammal, such as a mouse, rabbit, or rat), while the constant portion is sequence homologous to an antibody derived from another mammal (e.g., a human). In some embodiments, amino acid modifications may be made in the variable region and / or (e.g., and) the constant region.

[0395] In some embodiments, the anti-TfR antibodies described herein are chimeric antibodies, which may comprise a heavy constant region and a light constant region derived from a human antibody. A chimeric antibody is an antibody having a variable region or a portion thereof derived from a first species and a constant region derived from a second species. Typically, in these chimeric antibodies, the variable regions of both the light and heavy chains mimic the variable regions derived from antibodies of one mammal (e.g., non-human mammals such as mice, rabbits, and rats), while the constant portions are sequence homologous to those of antibodies derived from another mammal (e.g., humans). In some embodiments, amino acid modifications may be made in the variable regions and / or (e.g., and) the constant regions.

[0396] In some embodiments, the heavy chain of any anti-TfR antibody described herein may include a heavy chain constant region (CH) or a portion thereof (e.g., CH1, CH2, CH3, or combinations thereof). The heavy chain constant region may have any suitable source, such as human, mouse, rat, or rabbit. In one specific example, the heavy chain constant region is derived from human IgG, such as IgG1, IgG2, or IgG4 (γ heavy chain). An example of the human IgG1 constant region is given below:

[0397] .

[0398] In some embodiments, the heavy chain of any anti-TfR antibody described herein contains a mutant human IgG1 constant region. For example, it is known that introducing the LALA mutation (a mutant derived from mAb b12, which has been mutated to replace the lower hinge residues Leu234 and Leu235 with Ala234 and Ala235) into the CH2 domain of human IgG1 reduces Fcg receptor binding (Bruhns, P., et al. (2009) and Xu, D. et al. (2000)). The mutant human IgG1 constant region is shown below (mutations are bolded and underlined):

[0399] .

[0400] In some embodiments, the light chain of any anti-TfR antibody described herein may further comprise a light chain constant region (CL), which may be any CL known in the art. In some instances, the CL is a κ light chain. In other instances, the CL is a λ light chain. In some embodiments, the CL is a κ light chain, the sequence of which is provided below:

[0401] .

[0402] Other antibody heavy and light chain constant regions are well known in the art, such as those available in the IMGT database (www.imgt.org) or www.vbase2.org / vbstat.php, both of which are incorporated herein by reference.

[0403] In some embodiments, the anti-TfR antibody described herein comprises a heavy chain containing any VH or any variant thereof listed in Table 2, and a heavy chain constant region having at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identity with SEQ ID NO: 175 or SEQ ID NO: 176. In some embodiments, the anti-TfR antibody described herein comprises a heavy chain containing any VH or any variant thereof listed in Table 2, and a heavy chain constant region containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to SEQ ID NO: 175 or SEQ ID NO: 176. In some embodiments, the anti-TfR antibody described herein comprises a heavy chain, which includes any VH or any variant thereof listed in Table 2 and the heavy chain constant region shown in SEQ ID NO: 175. In some embodiments, the anti-TfR antibody described herein comprises a heavy chain, which includes any VH or any variant thereof listed in Table 2 and the heavy chain constant region shown in SEQ ID NO: 176.

[0404] In some embodiments, the anti-TfR antibody described herein comprises a light chain comprising any VL or any variant thereof listed in Table 2 and a light chain constant region having at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identity with SEQ ID NO: 177. In some embodiments, the anti-TfR antibody described herein comprises a light chain comprising any VL or any variant thereof listed in Table 2 and a light chain constant region comprising no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to SEQ ID NO: 177. In some embodiments, the anti-TfR antibody described herein comprises a light chain comprising any VL or any variant thereof listed in Table 2 and the light chain constant region shown in SEQ ID NO: 177.

[0405] Table 5 below provides some examples of the IgG heavy chain amino acid sequences and light chain amino acid sequences of the anti-TfR antibody.

[0406] Table 5. Heavy chain and light chain sequences of some examples of anti-TfR IgG

[0407]

[0408]

[0409]

[0410] *VH / VL sequences are underlined.

[0411] In some embodiments, the anti-TfR antibody of this disclosure comprises a heavy chain that contains no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation) compared to the heavy chains shown in SEQ ID NO:178, SEQ ID NO:180, SEQ ID NO:182, SEQ ID NO:303, SEQ ID NO:304, SEQ ID NO:305 or SEQ ID NO:306). As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a light chain containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation) compared to the light chains shown in SEQ ID NO: 179, SEQ ID NO: 181 or SEQ ID NO: 183. In some embodiments, the anti-TfR antibody described herein comprises a heavy chain containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with SEQ ID NO: 178, SEQ ID NO: 180, SEQ ID NO: 182, SEQ ID NO: 303, SEQ ID NO: 304, SEQ ID NO: 305, or SEQ ID NO: 306. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody described herein comprises a light chain containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with SEQ ID NO: 179, SEQ ID NO: 181, or SEQ ID NO: 183. In some embodiments, the anti-TfR antibody described herein comprises a heavy chain containing the amino acid sequence of SEQ ID NO: 178, SEQ ID NO: 180, SEQ ID NO: 182, SEQ ID NO: 303, SEQ ID NO: 304, SEQ ID NO: 305, or SEQ ID NO: 306. Alternatively or supplementally (e.g., additionally), the anti-TfR antibody described herein comprises a light chain containing the amino acid sequence of SEQ ID NO: 179, SEQ ID NO: 181, or SEQ ID NO: 183.

[0412] In some embodiments, the anti-TfR antibody of this disclosure comprises a heavy chain that contains no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation) compared to the heavy chain shown in SEQ ID NO: 178, SEQ ID NO: 303 or SEQ ID NO: 304. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a light chain containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 10, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the light chain shown in SEQ ID NO: 179. In some embodiments, the anti-TfR antibody described herein comprises a heavy chain containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with SEQ ID NO: 178, SEQ ID NO: 303, or SEQ ID NO: 304. As an alternative or supplement (e.g., supplement), the anti-TfR antibody described herein comprises a light chain containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with SEQ ID NO: 179. In some embodiments, the anti-TfR antibody described herein comprises a heavy chain containing the amino acid sequence of SEQ ID NO: 178, SEQ ID NO: 303, or SEQ ID NO: 304. As an alternative or supplement (e.g., supplement), the anti-TfR antibody described herein comprises a light chain containing the amino acid sequence of SEQ ID NO: 179.

[0413] In some embodiments, the anti-TfR antibody of this disclosure comprises a heavy chain containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the heavy chain shown in SEQ ID NO: 181. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises a light chain containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the light chain shown in SEQ ID NO: 181. In some embodiments, the anti-TfR antibody described herein comprises a heavy chain containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with SEQ ID NO: 180. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody described herein comprises a light chain containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with SEQ ID NO: 181. In some embodiments, the anti-TfR antibody described herein comprises a heavy chain containing the amino acid sequence of SEQ ID NO: 180. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody described herein comprises a light chain containing the amino acid sequence of SEQ ID NO: 181.

[0414] In some embodiments, the anti-TfR antibody of this disclosure comprises a heavy chain that contains no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation) compared to the heavy chain shown in SEQ ID NO: 182, SEQ ID NO: 305 or SEQ ID NO: 306. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a light chain containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the light chain shown in SEQ ID NO: 183. In some embodiments, the anti-TfR antibody described herein comprises a heavy chain containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with SEQ ID NO: 182, SEQ ID NO: 305, or SEQ ID NO: 306. As an alternative or supplement (e.g., supplement), the anti-TfR antibody described herein comprises a light chain containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with SEQ ID NO: 183. In some embodiments, the anti-TfR antibody described herein comprises a heavy chain containing the amino acid sequence of SEQ ID NO: 182, SEQ ID NO: 305, or SEQ ID NO: 306. As an alternative or supplement (e.g., supplement), the anti-TfR antibody described herein comprises a light chain containing the amino acid sequence of SEQ ID NO: 183.

[0415] In some embodiments, the anti-TfR antibody is a FAB fragment, F(ab') fragment, or F(ab')2 fragment of a complete antibody (full-length antibody). The antigen-binding fragment of the complete antibody (full-length antibody) can be prepared by conventional methods (e.g., recombinant methods or by digesting the heavy chain constant region of full-length IgG with an enzyme such as papain). For example, the F(ab')2 fragment can be generated by digesting the antibody molecule with pepsin or papain, and the Fab fragment can be generated by reducing the disulfide bridge of the F(ab')2 fragment. In some embodiments, the heavy chain constant region of the F(ab') fragment of the anti-TfR1 antibody described herein contains the following amino acid sequence:

[0416] .

[0417] In some embodiments, the anti-TfR antibody described herein comprises a heavy chain containing any VH or any variant thereof listed in Table 2 and a heavy chain constant region having at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identity with SEQ ID NO: 184. In some embodiments, the anti-TfR antibody described herein comprises a heavy chain containing any VH or any variant thereof listed in Table 2 and a heavy chain constant region containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to SEQ ID NO: 184. In some embodiments, the anti-TfR antibody described herein comprises a heavy chain comprising any VH or any variant thereof listed in Table 2 and the heavy chain constant region shown in SEQ ID NO: 184.

[0418] Table 6 provides some examples of the F(ab') amino acid sequences of the anti-TfR antibodies described in this paper.

[0419] Table 6. Heavy chain and light chain sequences of some instances of anti-TfR F(ab')

[0420]

[0421]

[0422]

[0423] VH / VL sequences are underlined.

[0424] In some embodiments, the anti-TfR antibody of this disclosure comprises a heavy chain that contains no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation) compared to the heavy chains shown in SEQ ID NO:185, SEQ ID NO:186, SEQ ID NO:187, SEQ ID NO:307, SEQ ID NO:308, SEQ ID NO:309 or SEQ ID NO:310). As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a light chain containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation) compared to the light chains shown in SEQ ID NO: 179, SEQ ID NO: 181 or SEQ ID NO: 183. In some embodiments, the anti-TfR antibody described herein comprises a heavy chain containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with SEQ ID NO: 185, SEQ ID NO: 186, SEQ ID NO: 187, SEQ ID NO: 307, SEQ ID NO: 308, SEQ ID NO: 309, or SEQ ID NO: 310. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody described herein comprises a light chain containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with SEQ ID NO: 179, SEQ ID NO: 181, or SEQ ID NO: 183. In some embodiments, the anti-TfR antibody described herein comprises a heavy chain containing the amino acid sequence of SEQ ID NO: 185, SEQ ID NO: 186, SEQ ID NO: 187, SEQ ID NO: 307, SEQ ID NO: 308, SEQ ID NO: 309, or SEQ ID NO: 310. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody described herein comprises a light chain containing the amino acid sequence of SEQ ID NO: 179, SEQ ID NO: 181, or SEQ ID NO: 183.

[0425] In some embodiments, the anti-TfR antibody of this disclosure comprises a heavy chain that contains no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation) compared to the heavy chain shown in SEQ ID NO: 185, SEQ ID NO: 307 or SEQ ID NO: 308. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a light chain containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the light chain shown in SEQ ID NO: 179. In some embodiments, the anti-TfR antibody described herein comprises a heavy chain containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with SEQ ID NO: 185, SEQ ID NO: 307, or SEQ ID NO: 308. As an alternative or supplement (e.g., supplement), the anti-TfR antibody described herein comprises a light chain containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with SEQ ID NO: 179. In some embodiments, the anti-TfR antibody described herein comprises a heavy chain containing the amino acid sequence of SEQ ID NO: 185, SEQ ID NO: 307, or SEQ ID NO: 308. As an alternative or supplement (e.g., supplement), the anti-TfR antibody described herein comprises a light chain containing the amino acid sequence of SEQ ID NO: 179.

[0426] In some embodiments, the anti-TfR antibody of this disclosure comprises a heavy chain containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the heavy chain shown in SEQ ID NO: 181. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises a light chain containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 10, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the light chain shown in SEQ ID NO: 181. In some embodiments, the anti-TfR antibody described herein comprises a heavy chain containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with SEQ ID NO: 186. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody described herein comprises a light chain containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with SEQ ID NO: 181. In some embodiments, the anti-TfR antibody described herein comprises a heavy chain containing the amino acid sequence of SEQ ID NO: 186. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody described herein comprises a light chain containing the amino acid sequence of SEQ ID NO: 181.

[0427] In some embodiments, the anti-TfR antibody of this disclosure comprises a heavy chain that contains no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation) compared to the heavy chain shown in SEQ ID NO: 187, SEQ ID NO: 309 or SEQ ID NO: 310. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises a light chain containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the light chain shown in SEQ ID NO: 183. In some embodiments, the anti-TfR antibody described herein comprises a heavy chain containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with SEQ ID NO: 187, SEQ ID NO: 309, or SEQ ID NO: 310. As an alternative or supplement (e.g., supplement), the anti-TfR antibody described herein comprises a light chain containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with SEQ ID NO: 183. In some embodiments, the anti-TfR antibody described herein comprises a heavy chain containing the amino acid sequence of SEQ ID NO: 187, SEQ ID NO: 309, or SEQ ID NO: 310. As an alternative or supplement (e.g., supplement), the anti-TfR antibody described herein comprises a light chain containing the amino acid sequence of SEQ ID NO: 183.

[0428] The anti-TfR receptor antibody described herein can be any antibody form, including but not limited to full-length antibodies, their antigen-binding fragments (e.g., Fab, F(ab'), F(ab')2, Fv), single-chain antibodies, bispecific antibodies, or nanobodies. In some embodiments, the anti-TfR antibody described herein is an scFv. In some embodiments, the anti-TfR antibody described herein is an scFv-Fab (e.g., an scFv fused to a portion of a constant region). In some embodiments, the anti-TfR receptor antibody described herein is an scFv fused to a constant region (e.g., the human IgG1 constant region shown in SEQ ID NO: 175 or SEQ ID NO: 176, or a portion thereof, such as the Fc portion) at the C-terminus or N-terminus.

[0429] In some embodiments, any of the anti-TfR1 antibodies described herein may include a signal peptide (e.g., an N-terminal signal peptide) in the heavy chain sequence and / or (e.g., and) the light chain sequence. In some embodiments, the anti-TfR1 antibody described herein comprises any of the VH and VL sequences, any of the IgG heavy chain and light chain sequences, or any of the F(ab') heavy chain and light chain sequences described herein, and further comprises a signal peptide (e.g., an N-terminal signal peptide). In some embodiments, the signal peptide comprises an amino acid sequence. .

[0430] In some aspects, this disclosure provides another novel anti-TfR antibody that can be used as a muscle target agent (e.g., in a muscle-targeting complex). The CDR sequence and variable domain sequence of the said antibody are provided in Table 7.

[0431] Table 7. CDR sequences and variable domain sequences of anti-TfR antibodies according to different definition systems

[0432]

[0433] In some embodiments, the anti-TfR antibody of this disclosure comprises one or more CDR-H (e.g., CDR-H1, CDR-H2, and CDR-H3) amino acid sequences selected from any of the anti-TfR antibodies in Table 7. In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3 as provided for each numbering system provided in Table 7. In some embodiments, the TfR antibody of this disclosure comprises one or more CDR-L (e.g., CDR-L1, CDR-L2, and CDR-L3) amino acid sequences selected from any of the anti-TfR antibodies in Table 7. In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3 as provided for the teaching numbering system provided in Table 7.

[0434] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2, and CDR-L3 as provided for each numbering system provided in Table 7. In some embodiments, the CDR3 domains of both the antibody heavy and light chains may play a particularly important role in the antibody's binding specificity / affinity to the antigen. Therefore, the anti-TfR antibody of this disclosure may comprise at least the heavy chain and / or (e.g., and) light chain CDR3 of any of the anti-TfR antibodies provided in Table 7.

[0435] In some instances, any anti-TfR antibody of this disclosure has one or more CDR (e.g., CDR-H or CDR-L) sequences substantially similar to any CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2 and / or (e.g., and) CDR-L3 sequences provided in Table 7. In some embodiments, the position of one or more CDRs along the VH (e.g., CDR-H1, CDR-H2 or CDR-H3) and / or (e.g., and) VL (e.g., CDR-L1, CDR-L2 or CDR-L3) regions of the antibody described herein may vary by one, two, three, four, five or six amino acid positions, provided that immune-specific binding to the transferrin receptor (e.g., human transferrin receptor) is maintained (e.g., substantially maintaining binding to the original antibody from which it is derived, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%). For example, in some embodiments, the location of the CDR of any antibody described herein can be defined by shifting the N-terminal and / or (e.g., and) C-terminal boundary of the CDR relative to the CDR location of any antibody described herein by one, two, three, four, five, or six amino acids, as long as immune-specific binding to the transferrin receptor (e.g., human transferrin receptor) is maintained (e.g., substantially maintaining binding to the original antibody from which it is derived, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%). In another embodiment, the length of one or more CDRs along the VH (e.g., CDR-H1, CDR-H2, or CDR-H3) and / or (e.g., and) VL (e.g., CDR-L1, CDR-L2, or CDR-L3) regions of the antibody described herein may be altered (e.g., become shorter or longer) by one, two, three, four, five, or more amino acids, as long as immune-specific binding to the transferrin receptor (e.g., human transferrin receptor) is maintained (e.g., substantially maintaining binding to the original antibody from which it originates, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%).

[0436] Therefore, in some embodiments, the CDR-L1, CDR-L2, CDR-L3, CDR-H1, CDR-H2 and / or (e.g., and) CDR-H3 described herein may be one, two, three, four, five or more amino acids shorter than one or more CDRs described herein (e.g., those provided in Table 7), as long as immune-specific binding to the transferrin receptor (e.g., human transferrin receptor) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%) relative to the binding of the original antibody from which it is derived. In some embodiments, the CDR-L1, CDR-L2, CDR-L3, CDR-H1, CDR-H2 and / or (e.g., and) CDR-H3 described herein may be one, two, three, four, five or more amino acids longer than one or more CDRs described herein (e.g., CDRs from anti-TfR antibodies provided in Table 7), as long as immune-specific binding to the transferrin receptor (e.g., human transferrin receptor) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%) relative to the binding of the original antibody from which it is derived. In some embodiments, the amino moiety of CDR-L1, CDR-L2, CDR-L3, CDR-H1, CDR-H2 and / or (e.g., and) CDR-H3 described herein may be extended by one, two, three, four, five or more amino acids compared to one or more CDRs described herein (e.g., CDRs from anti-TfR antibodies provided in Table 7), as long as the immune-specific binding to the transferrin receptor (e.g., human transferrin receptor) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%) relative to the binding of the original antibody from which it is derived. In some embodiments, the carboxyl moiety of CDR-L1, CDR-L2, CDR-L3, CDR-H1, CDR-H2 and / or (e.g., and) CDR-H3 described herein may be extended by one, two, three, four, five or more amino acids compared to one or more CDRs described herein (e.g., CDRs from anti-TfR antibodies provided in Table 7), as long as the immune-specific binding to the transferrin receptor (e.g., human transferrin receptor) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%) relative to the binding to the original antibody from which it is derived.In some embodiments, the amino moiety of CDR-L1, CDR-L2, CDR-L3, CDR-H1, CDR-H2 and / or (e.g., and) CDR-H3 described herein may be shortened by one, two, three, four, five or more amino acids compared to one or more CDRs described herein (e.g., CDRs from anti-TfR antibodies provided in Table 7), as long as immune-specific binding to the transferrin receptor (e.g., human transferrin receptor) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, relative to the binding of the original antibody from which it is derived). In some embodiments, the carboxyl moiety of CDR-L1, CDR-L2, CDR-L3, CDR-H1, CDR-H2 and / or (e.g., and) CDR-H3 described herein may be shortened by one, two, three, four, five or more amino acids compared to one or more CDRs described herein (e.g., CDRs from anti-TfR antibodies provided in Table 7), as long as immune-specific binding to the transferrin receptor (e.g., human transferrin receptor) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%) relative to the binding of the original antibody from which it is derived. Any method may be used to determine whether immune-specific binding to the transferrin receptor (e.g., human transferrin receptor) is maintained, for example using binding assays and conditions described in the art.

[0437] In some instances, any anti-TfR antibody of this disclosure has one or more CDR (e.g., CDR-H or CDR-L) sequences substantially similar to any of the anti-TfR antibodies provided in Table 7. For example, the antibody may comprise one or more CDR sequences from the anti-TfR antibodies provided in Table 7, and may contain up to 5, 4, 3, 2, or 1 amino acid residue variations compared to the corresponding CDR region in any of the CDRs provided herein (e.g., CDRs from the anti-TfR antibodies provided in Table 7), provided that immune-specific binding to the transferrin receptor (e.g., human transferrin receptor) is maintained (e.g., substantially maintained, for example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%) relative to the binding of the original antibody from which it originates. In some embodiments, any amino acid variation in any CDR provided herein may be a conserved variation. Conserved variations may be introduced into the CDR at locations where residues are unlikely to interact with the transferrin receptor protein (e.g., human transferrin receptor protein) (e.g., as determined based on crystal structure).

[0438] Some aspects of this disclosure provide anti-TfR antibodies comprising one or more heavy chain variable (VH) and / or (e.g., and) light chain variable (VL) domains as provided herein. In some embodiments, the anti-TfR antibodies of this disclosure comprise any antibody containing the heavy chain variable domain and / or (e.g., and) light chain variable domain of the anti-TfR1 antibodies provided in Table 7.

[0439] Some aspects of this disclosure provide anti-TfR antibodies having a heavy chain variable (VH) and / or (e.g., and) light chain variable (VL) amino acid sequence homologous to any of those described herein. In some embodiments, the anti-TfR antibody comprises a heavy chain variable sequence or light chain variable sequence having at least 75% (e.g., 80%, 85%, 90%, 95%, 98%, or 99%) identity with the heavy chain variable sequences and / or any light chain variable sequences provided in Table 7. In some embodiments, the homologous heavy chain variable and / or (e.g., and) light chain variable amino acid sequences remain unchanged within any CDR sequences provided herein. For example, in some embodiments, the degree of sequence variation (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) may occur in the heavy chain variable and / or (e.g., and) light chain variable sequences excluding any CDR sequences provided herein. In some implementations, any anti-TfR antibody provided herein contains a heavy chain variable sequence and a light chain variable sequence, which contains a frame sequence having at least 75%, 80%, 85%, 90%, 95%, 98%, or 99% identity with the frame sequence of any anti-TfR antibody provided in Table 7.

[0440] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which are heavy chain variable domains having the amino acid sequence of SEQ ID NO: 204. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which are light chain variable domains having the amino acid sequence of SEQ ID NO: 205.

[0441] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 188, CDR-H2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 189, CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 190, CDR-L1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 191, CDR-L2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 192, and CDR-L3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 193.

[0442] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which, compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 188, CDR-H2 having the amino acid sequence of SEQ ID NO: 189, and CDR-H3 having the amino acid sequence of SEQ ID NO: 190, collectively comprise no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation). Alternatively or supplementally (e.g., as a supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which, compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 191, CDR-L2 having the amino acid sequence of SEQ ID NO: 192, and CDR-L3 having the amino acid sequence of SEQ ID NO: 193, collectively comprise no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation).

[0443] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-H1 having the amino acid sequence of SEQ ID NO: 188, CDR-H2 having the amino acid sequence of SEQ ID NO: 189, and CDR-H3 having the amino acid sequence of SEQ ID NO: 190. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-L1 having the amino acid sequence of SEQ ID NO: 191, CDR-L2 having the amino acid sequence of SEQ ID NO: 192, and CDR-L3 having the amino acid sequence of SEQ ID NO: 193.

[0444] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 188; CDR-H2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 189; and / or (e.g., and) CDR-H3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 190. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: CDR-L1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 191; CDR-L2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 192; and / or (e.g., and) CDR-L3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 193.

[0445] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 194, CDR-H2 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 195, CDR-H3 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 196, CDR-L1 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 197, CDR-L2 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 198, and CDR-L3 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 193.

[0446] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which, compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 194, CDR-H2 having the amino acid sequence of SEQ ID NO: 195, and CDR-H3 having the amino acid sequence of SEQ ID NO: 196, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation). "Commonly" means that the total number of amino acid variations in all three heavy chain CDRs is within the defined range. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 197, CDR-L2 having the amino acid sequence of SEQ ID NO: 198, and CDR-L3 having the amino acid sequence of SEQ ID NO: 193.

[0447] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-H1 having the amino acid sequence of SEQ ID NO: 194, CDR-H2 having the amino acid sequence of SEQ ID NO: 195, and CDR-H3 having the amino acid sequence of SEQ ID NO: 196. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-L1 having the amino acid sequence of SEQ ID NO: 197, CDR-L2 having the amino acid sequence of SEQ ID NO: 198, and CDR-L3 having the amino acid sequence of SEQ ID NO: 193.

[0448] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 194; CDR-H2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 195; and / or (e.g., and) CDR-H3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 196. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: CDR-L1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 197; CDR-L2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 198; and / or (e.g., and) CDR-L3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 193.

[0449] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 199, CDR-H2 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 200, CDR-H3 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 201, CDR-L1 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 202, CDR-L2 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 192, and CDR-L3 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 203.

[0450] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which, compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 199, CDR-H2 having the amino acid sequence of SEQ ID NO: 200, and CDR-H3 having the amino acid sequence of SEQ ID NO: 201, collectively contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation). "Commonly" means that the total number of amino acid variations in all three heavy chain CDRs is within the defined range. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together contain no more than 5 amino acid variations (e.g., no more than 5, 4, 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 202, CDR-L2 having the amino acid sequence of SEQ ID NO: 192, and CDR-L3 having the amino acid sequence of SEQ ID NO: 203.

[0451] In some embodiments, the anti-TfR antibody of this disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-H1 having the amino acid sequence of SEQ ID NO: 199, CDR-H2 having the amino acid sequence of SEQ ID NO: 200, and CDR-H3 having the amino acid sequence of SEQ ID NO: 201. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together have at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with CDR-L1 having the amino acid sequence of SEQ ID NO: 202, CDR-L2 having the amino acid sequence of SEQ ID NO: 192, and CDR-L3 having the amino acid sequence of SEQ ID NO: 203.

[0452] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 199; CDR-H2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 200; and / or (e.g., and) CDR-H3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 201. As an alternative or supplement (e.g., supplement), the anti-TfR antibody of this disclosure comprises: CDR-L1 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 202; CDR-L2 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 192; and / or (e.g., and) CDR-L3 having no more than 3 amino acid variations (e.g., no more than 3, 2, or 1 amino acid variation) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 203.

[0453] In some embodiments, the anti-TfR antibody of this disclosure comprises: CDR-H1 containing the amino acid sequence of SEQ ID NO: 194, CDR-H2 containing the amino acid sequence of SEQ ID NO: 189, CDR-H3 containing the amino acid sequence of SEQ ID NO: 196, CDR-L1 containing the amino acid sequence of SEQ ID NO: 197, CDR-L2 containing the amino acid sequence of SEQ ID NO: 198, and CDR-L3 containing the amino acid sequence of SEQ ID NO: 193.

[0454] In some embodiments, the anti-TfR antibody of this disclosure is a human antibody comprising a VH containing the amino acid sequence of SEQ ID NO: 204. Alternatively or supplementally (e.g., as an alternative), the anti-TfR antibody of this disclosure is a human antibody comprising a VL containing the amino acid sequence of SEQ ID NO: 205. In some embodiments, this disclosure contemplates other humanized antibodies / human antibodies comprising CDR-H1, CDR-H1, CDR-H3 of VH containing SEQ ID NO: 204 and CDR-L1, CDR-L1, and CDR-L3 of VL containing SEQ ID NO: 205, and a human frame region.

[0455] In some embodiments, the anti-TfR antibody of this disclosure comprises a VH containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VH shown in SEQ ID NO: 205. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises a VL containing no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) compared to the VL shown in SEQ ID NO: 205.

[0456] In some embodiments, the anti-TfR antibody of this disclosure comprises VH, said VH containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VH shown in SEQ ID NO: 204. Alternatively or supplementally (e.g., as an adjunct), the anti-TfR antibody of this disclosure comprises VL, said VL containing an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VL shown in SEQ ID NO: 205.

[0457] In some embodiments, the anti-TfR antibody of this disclosure is a humanized antibody. In some embodiments, the humanized anti-TfR antibody comprises a humanized VH and a humanized VL, wherein the humanized VH comprises CDR-H1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 188, CDR-H2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 189, and CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 190; the humanized VL comprises CDR-L1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 191, CDR-L2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 192, and CDR-L3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 193, wherein the humanized VH comprises amino acids with the amino acid sequence of SEQ ID NO: 191. The VH shown in SEQ ID NO: 204 has an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical, and the humanized VL contains an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL shown in SEQ ID NO: 205.

[0458] In some embodiments, the humanized anti-TfR antibody comprises a humanized VH and a humanized VL, wherein the humanized VH comprises CDR-H1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 188, CDR-H2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 189, and CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 190; the humanized VL comprises CDR-L1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 191, CDR-L2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 192, and CDR-L3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 193, wherein the amino acid sequence of SEQ ID NO: 193 is the same as that of SEQ ID NO: 194. Compared to the VH shown in SEQ ID NO: 204, the humanized VH contains no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation), and compared to the VL shown in SEQ ID NO: 205, the humanized VL contains no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation).

[0459] In some embodiments, the humanized anti-TfR antibody comprises a humanized VH having the amino acid sequence of SEQ ID NO: 194, CDR-H1 (according to the Kabat definition system), CDR-H2 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 195, and CDR-H3 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 196; CDR-L1 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 197; CDR-L2 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 198; and CDR-L3 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 193, wherein the humanized VH comprises an amino acid sequence having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity with the VH shown in SEQ ID NO: 204; and the humanized VL ... The VL shown in 205 has an amino acid sequence with at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identity.

[0460] In some embodiments, the humanized anti-TfR antibody comprises CDR-H1 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 194, CDR-H2 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 195, CDR-H3 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 196, CDR-L1 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 197, CDR-L2 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 198, and CDR-L3 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 193, wherein the amino acid sequence of SEQ ID NO: 194 is... Compared to the VH shown in SEQ ID NO: 204, the humanized VH contains no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation) and compared to the VL shown in SEQ ID NO: 205, the humanized VL contains no more than 25 amino acid variations (e.g., no more than 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 amino acid variation).

[0461] In some embodiments, the humanized anti-TfR antibody comprises a humanized VH having the amino acid sequence of SEQ ID NO: 199, CDR-H1 (according to the Chothia definition system), CDR-H2 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 200, CDR-H3 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 201, CDR-L1 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 202, CDR-L2 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 192, and CDR-L3 (according to the Chothia definition sy...

Claims

1. A complex comprising an anti-transferrin receptor antibody covalently linked to a molecular payload, said molecular payload being configured to inhibit the expression or activity of dual homeobox 4 (DUX4), wherein: (i) The antibody comprises heavy chain complementarity-determining region 1 (CDR-H1), heavy chain complementarity-determining region 2 (CDR-H2), and heavy chain complementarity-determining region 3 (CDR-H3) containing the heavy chain variable region (VH) of the amino acid sequence of SEQ ID NO: 15, and light chain complementarity-determining region 1 (CDR-L1), light chain complementarity-determining region 2 (CDR-L2), and light chain complementarity-determining region 3 (CDR-L3) containing the light chain variable region (VL) of the amino acid sequence of SEQ ID NO:

16. (ii) The antibody comprises CDR-H1, CDR-H2 and CDR-H3 of VH containing the amino acid sequence of SEQ ID NO: 204, and CDR-L1, CDR-L2 and CDR-L3 of VL containing the amino acid sequence of SEQ ID NO: 205; (iii) The antibody comprises CDR-H1, CDR-H2, and CDR-H3 of VH containing the amino acid sequence of SEQ ID NO: 7, and CDR-L1, CDR-L2, and CDR-L3 of VL containing the amino acid sequence of SEQ ID NO: 8; or (iv) The antibody comprises CDR-H1, CDR-H2 and CDR-H3 of VH containing the amino acid sequence of SEQ ID NO: 23, and CDR-L1, CDR-L2 and CDR-L3 of VL containing the amino acid sequence of SEQ ID NO:

24.

2. The complex of claim 1, wherein the antibody comprises: (i) CDR-H1 of SEQ ID NO: 155, CDR-H2 of SEQ ID NO: 156, CDR-H3 of SEQ ID NO: 157, CDR-L1 of SEQ ID NO: 158, CDR-L2 of SEQ ID NO: 159 and CDR-L3 of SEQ ID NO: 14; (ii) CDR-H1 of SEQ ID NO: 194, CDR-H2 of SEQ ID NO: 195, CDR-H3 of SEQ ID NO: 196, CDR-L1 of SEQ ID NO: 197, CDR-L2 of SEQ ID NO: 198 and CDR-L3 of SEQ ID NO: 193; (iii) CDR-H1 of SEQ ID NO: 145, CDR-H2 of SEQ ID NO: 146, SEQ ID NO: 267 or SEQ ID NO: 269, CDR-H3 of SEQ ID NO: 147, CDR-L1 of SEQ ID NO: 148, CDR-L2 of SEQ ID NO: 149 and CDR-L3 of SEQ ID NO: 6; or (iv) CDR-H1 of SEQ ID NO: 165, SEQ ID NO: 271 or SEQ ID NO: 273, CDR-H2 of SEQ ID NO: 166, CDR-H3 of SEQ ID NO: 167, CDR-L1 of SEQ ID NO: 168, CDR-L2 of SEQ ID NO: 169 and CDR-L3 of SEQ ID NO:

22.

3. The complex of claim 1 or claim 2, wherein the antibody comprises a human or humanized frame region having the following: (i) CDR-H1, CDR-H2, and CDR-H3 of VH shown in SEQ ID NO: 15, and CDR-L1, CDR-L2, and CDR-L3 of VL shown in SEQ ID NO: 16; (ii) CDR-H1, CDR-H2, and CDR-H3 of VH shown in SEQ ID NO: 204, and CDR-L1, CDR-L2, and CDR-L3 of VL shown in SEQ ID NO: 205; (iii) CDR-H1, CDR-H2, and CDR-H3 of VH shown in SEQ ID NO: 7, and CDR-L1, CDR-L2, and CDR-L3 of VL shown in SEQ ID NO: 8; or (iv) CDR-H1, CDR-H2, and CDR-H3 of VH shown in SEQ ID NO: 23, and CDR-L1, CDR-L2, and CDR-L3 of VL shown in SEQ ID NO:

24.

4. The complex of any one of claims 1 to 3, wherein the antibody is selected from: (i) An antibody comprising a VH containing an amino acid sequence having at least 80% identity with SEQ ID NO: 15 and a VL containing an amino acid sequence having at least 80% identity with SEQ ID NO: 16; (ii) An antibody comprising a VH containing an amino acid sequence having at least 80% identity with SEQ ID NO: 204 and a VL containing an amino acid sequence having at least 80% identity with SEQ ID NO: 205, wherein optionally the antibody comprises a VH containing an amino acid sequence of SEQ ID NO: 204 and a VL containing an amino acid sequence of SEQ ID NO: 205; (iii) An antibody comprising VH containing an amino acid sequence having at least 80% identity with SEQ ID NO: 7 and VL containing an amino acid sequence having at least 80% identity with SEQ ID NO: 8; and (iv) An antibody comprising VH containing an amino acid sequence having at least 80% identity with SEQ ID NO: 23 and VL containing an amino acid sequence having at least 80% identity with SEQ ID NO:

24.

5. The complex of any one of claims 1 to 4, wherein the equilibrium dissociation constant (K0) of the antibody binding to the transferrin receptor is... D ) is 10 -11 M to 10 -6 M.

6. The complex of any one of claims 1 to 5, wherein the antibody is selected from full-length IgG, Fab fragment, F(ab') fragment, F(ab')2 fragment, scFv and Fv, optionally wherein the antibody is a Fab' fragment.

7. The complex of any one of claims 1 to 6, wherein the molecular load is an oligonucleotide.

8. The complex of claim 7, wherein the oligonucleotide comprises an antisense strand of 18 to 30 nucleotides in length and includes a region complementary to at least 15 consecutive nucleotides of SEQ ID NO: 258 or 339, optionally wherein the antisense strand includes a region complementary to at least 15 consecutive nucleotides of SEQ ID NO:

261.

9. The complex of claim 8, wherein the oligonucleotide comprises At least 15 consecutive nucleotides, wherein each T is optionally and independently U, wherein said oligonucleotides optionally contain The nucleotide sequence, wherein each T is optionally and independently U.

10. The complex of any one of claims 6 to 9, wherein the oligonucleotide comprises one or more phosphodiamidomorpholino groups, optionally wherein the oligonucleotide is a phosphodiamidomorpholino oligomer (PMO).

11. The complex of any one of claims 8 to 10, wherein the oligonucleotide further comprises a sense strand that hybridizes with the antisense strand to form a double-stranded siRNA.

12. The complex of claim 11, wherein the oligonucleotide comprises at least one modified nucleoside link, optionally wherein the at least one modified nucleoside link is a phosphate thioester link.

13. The complex of claim 11 or claim 12, wherein the oligonucleotide comprises one or more modified nucleosides.

14. The complex of claim 13, wherein one or more of the modified nucleosides are 2' modified nucleosides.

15. The complex of claim 14, wherein the 2' modified nucleotide is selected from: 2'-O-methyl (2'-O-Me), 2'-fluoro (2'-F), 2'-O-methoxyethyl (2'-MOE), and 2',4'-bicyclic nucleotide.

16. The complex of claim 15, wherein the 2',4'-bicyclic nucleotide is selected from: locked nucleic acid (LNA), ethylidene bridging nucleic acid (ENA), and (S)-restricted ethyl bridging nucleic acid (cEt).

17. The complex of any one of claims 1 to 16, wherein the muscle-targeting agent is covalently linked to the molecular load via the following: (i) a cuttable connector, optionally wherein the cuttable connector comprises a valine-citrulline dipeptide sequence; or (ii) an uncuttable joint, optionally wherein the uncuttable joint is an alkane joint.

18. The complex of any one of claims 1 to 17, wherein the molecular load is linked to the antibody by conjugation to a lysine residue or a cysteine ​​residue of the antibody.

19. A method for inhibiting the expression or activity of DUX4 in cells, the method comprising contacting the cells with a complex effective for promoting the internalization of molecular load into the cells in an amount according to any one of claims 1 to 18.

20. A method for treating a subject having one or more deletions of the D4Z4 repeat associated with facioscapulohumeral muscular dystrophy (FSHD) on chromosome 4, the method comprising administering to the subject an effective amount of the complex of any one of claims 1 to 18.

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