Muscle targeting complexes and their use

Abstract

Aspects of the present disclosure relate to conjugates comprising a muscle targeting agent covalently linked to a molecular payload. In some embodiments, the muscle targeting agent specifically binds to an internalized cell surface receptor on muscle cells. In some embodiments, the molecular payload inhibits the activity of a disease allele associated with a muscle disease. In some embodiments, the molecular payload is an oligonucleotide, such as an antisense oligonucleotide or an RNAi oligonucleotide.

Description

Technical Field

[0001] Related Applications This application claims the benefit under 35 U.S.C. § 119(e) of the filing dates of 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 / 069,067, filed August 23, 2020, entitled "MUSCLE-TARGETING COMPLEXES AND USES THEREOF"; U.S. Provisional Application No. 63 / 061,836, filed August 6, 2020, entitled "MUSCLE-TARGETING COMPLEXES AND USES THEREOF"; U.S. Provisional Application No. 63 / 055,521, filed July 23, 2020, entitled "MUSCLE-TARGETING COMPLEXES AND USES THEREOF"; U.S. Provisional Application No. 62 / 980,925, filed February 24, 2020, entitled "MUSCLE-TARGETING COMPLEXES AND USES THEREOF"; U.S. Provisional Application No. 62 / 968,411, filed January 31, 2020, entitled "MUSCLE-TARGETING COMPLEXES AND USES THEREOF"; U.S. Provisional Application No. 62 / 965,754, filed January 24, 2020, entitled "MUSCLE-TARGETING COMPLEXES AND USES THEREOF"; and U.S. Provisional Application No. 62 / 959,804, filed January 10, 2020, entitled "MUSCLE-TARGETING COMPLEXES AND USES THEREOF"; the contents of each of which are hereby incorporated herein by reference in their entirety.

[0002] Field of the Invention This application relates to targeted complexes for delivering molecular payloads (e.g., oligonucleotides) to cells, and their use, particularly for the treatment of diseases.

[0003] References to sequence listings submitted as text files via EFS-WEB This application contains a sequence listing, which was submitted via EFS-Web in ASCII format and is incorporated herein by reference in its entirety. The ASCII copy, created on 8 January 2021, is named D082470032WO00-SEQ-ZJG and is 1930 kilobytes in size. [Background technology]

[0004] background Muscle diseases are often associated with muscle weakness and / or (e.g., and) muscle dysfunction, leading to life-threatening complications. Many examples of such diseases have been characterized and include muscular dystrophy (e.g., Duchenne, facioscapulohumeral, myotonic, and oculopharyngeal), Pompe disease, central nucleus myopathy, familial hypertrophic cardiomyopathy, distal Rein myopathy, fibrodysplasia ossificans progressive, Friedreich's ataxia, myofibril myopathy, and various other forms. These diseases are generally hereditary but can occur spontaneously. These diseases are often congenital but can also occur later in life. Many rare muscle diseases are single gene disorders associated with gain-of-function or loss-of-function mutations, which may have dominant or recessive phenotypes. For example, activating mutations have been identified in genes encoding ion channels, structural proteins, metabolites, and signaling proteins that contribute to muscle disease. Despite advances in our understanding of the genetic etiology of muscle diseases, effective treatment options remain limited. [Overview of the project]

[0005] overview In some aspects, this disclosure provides complexes that target muscle cells for the purpose of delivering molecular payloads to those cells. In some embodiments, the complexes of this disclosure facilitate muscle-specific delivery of molecular payloads targeting muscle disease alleles. For example, in some embodiments, the complexes provided herein are particularly useful for delivering molecular payloads that modulate gene expression or activity in subjects having or suspected of having a muscle disease associated with that gene (e.g., genes / diseases in Table 1). In some embodiments, the complexes provided herein include a muscle targeting agent (e.g., a muscle-targeting antibody) that specifically binds to a receptor on the surface of a muscle cell for the purpose of delivering a molecular payload to the muscle cell. In some embodiments, the complex may be taken up into the cell via receptor-mediated internalization (e.g., a transferrin receptor), and the molecular payload may be released into the cell to perform its function. For example, a complex modified to deliver an oligonucleotide may release an oligonucleotide so that the oligonucleotide can modulate the expression or activity of a muscle disease allele. In some embodiments, the oligonucleotides are released by endosomal cleavage of a covalent linker that connects the oligonucleotides of the complex to the muscle targeting agent.

[0006] In some embodiments, methods are provided for treating subjects diagnosed with a muscle disease associated with a disease allele (e.g., a gain-of-function disease allele). In some embodiments, the method involves administering to a subject a complex comprising a muscle targeting agent covalently linked to a molecular payload configured to inhibit the expression or activity of the disease allele. In some embodiments, the muscle targeting agent specifically binds to internalized cell surface receptors on the muscle cells of the subject. In some embodiments, the muscle disease may be hereditary and present with increased severity across generations of the subject's family. In some embodiments, the subject has been diagnosed with a muscle disease based on genetic analysis of the disease allele. In some embodiments, the subject presents with progressive muscle weakness and / or (e.g., and) muscle loss prior to administration. In some embodiments, the subject presents with myotonia prior to administration.

[0007] Several aspects of this disclosure provide a complex comprising an anti-transferrin receptor antibody covalently linked to a molecular payload configured to modulate the expression or activity of a muscle disease gene. 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 of the anti-TfR antibodies listed in Tables 2, 4, and 7.

[0008] In some embodiments, the antibody comprises CDR-H1, CDR-H2, and CDR-H3 of the heavy chain variable region (VH) containing the amino acid sequence of SEQ ID NO: 15, and CDR-L1, CDR-L2, and CDR-L3 of the light chain variable region (VL) containing the amino acid sequence of SEQ ID NO: 16. In some embodiments, the antibody comprises CDR-H1, CDR-H2, and CDR-H3 of the VH containing the amino acid sequence of SEQ ID NO: 204, and CDR-L1, CDR-L2, and CDR-L3 of the VL containing the amino acid sequence of SEQ ID NO: 205. In some embodiments, the antibody comprises CDR-H1, CDR-H2, and CDR-H3 of the VH containing the amino acid sequence of SEQ ID NO: 7, and CDR-L1, CDR-L2, and CDR-L3 of the VL containing the amino acid sequence of SEQ ID NO: 8. In some aspects, the antibody comprises VH CDR-H1, CDR-H2, and CDR-H3 containing the amino acid sequence of SEQ ID NO: 23, and VL CDR-L1, CDR-L2, and CDR-L3 containing the amino acid sequence of SEQ ID NO: 24.

[0009] 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, CDR-H2 of SEQ ID NO: 263, or CDR-H2 of SEQ ID NO: 265, 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: 267, or SEQ ID NO: 269, 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.

[0010] In some embodiments, the antibody comprises a human or humanized framework region and has VH CDR-H1, CDR-H2, CDR-H3 as represented by SEQ ID NO: 15, and VL CDR-L1, CDR-L2, CDR-L3 as represented by SEQ ID NO: 16. In some embodiments, the antibody comprises a human or humanized framework region and has VH CDR-H1, CDR-H2, CDR-H3 as represented by SEQ ID NO: 204, and VL CDR-L1, CDR-L2, CDR-L3 as represented by SEQ ID NO: 205. In some embodiments, the antibody comprises a human or humanized framework region and has VH CDR-H1, CDR-H2, CDR-H3 as represented by SEQ ID NO: 7, and VL CDR-L1, CDR-L2, CDR-L3 as represented by SEQ ID NO: 8. In some embodiments, the antibody comprises a human or humanized framework region and has VH CDR-H1, CDR-H2, CDR-H3 as represented by SEQ ID NO: 23, and VL CDR-L1, CDR-L2, CDR-L3 as represented by SEQ ID NO: 24.

[0011] In some embodiments, the antibody comprises a VH having an amino acid sequence at least 80% identical to SEQ ID NO: 15 and a VL having an amino acid sequence at least 80% identical to SEQ ID NO: 16. In some embodiments, the antibody comprises a VH having an amino acid sequence at least 80% identical to SEQ ID NO: 204 and a VL having an amino acid sequence at least 80% identical to SEQ ID NO: 205. In some embodiments, the antibody comprises a VH having an amino acid sequence at least 80% identical to SEQ ID NO: 7 and a VL having an amino acid sequence at least 80% identical to SEQ ID NO: 8. In some embodiments, the antibody comprises a VH having an amino acid sequence at least 80% identical to SEQ ID NO: 23 and a VL having an amino acid sequence at least 80% identical to SEQ ID NO: 24. In some embodiments, the antibody comprises a VH having an amino acid sequence of SEQ ID NO: 204 and a VL having an amino acid sequence of SEQ ID NO: 205.

[0012] In some embodiments, the equilibrium dissociation constant (KD) for antibody binding to the transferrin receptor is 10 -11 M to 10 -6 It falls within the range up to M.

[0013] In some embodiments, the antibody is selected from the group consisting of full-length IgG, Fab fragment, F(ab') fragment, F(ab')2 fragment, scFv, and Fv. In some embodiments, the antibody is a Fab' fragment.

[0014] In some embodiments, the molecular payload is an oligonucleotide. In some embodiments, the oligonucleotide includes at least one modified nucleoside linkage. In some embodiments, at least one modified nucleoside linkage is a phosphorothioate linkage.

[0015] In some embodiments, the oligonucleotide comprises one or more modified nucleotides. In some embodiments, one or more modified nucleotides are 2'-modified nucleotides. In some embodiments, the 2'-modified nucleotide is selected from the group consisting of 2'-O-methyl (2'-O-Me), 2'-fluoro (2'-F), 2'-O-methoxyethyl (2'-MOE), and 2',4'-bicyclic nucleosides. In some embodiments, the 2',4'-bicyclic nucleosides are selected from the group consisting of locked nucleic acids (LNA), ethylene-bridged nucleic acids (ENA), and (S)-restricted ethyl-bridged nucleic acids (cEt).

[0016] In some embodiments, the oligonucleotides are gapmer oligonucleotides that are directed towards RNAse H-mediated cleavage of mRNA transcripts encoded by muscle disease genes in cells. In some embodiments, the oligonucleotide is a mixmer oligonucleotide.

[0017] In some embodiments, the oligonucleotide is an RNAi oligonucleotide that facilitates RNAi-mediated cleavage of mRNA transcripts encoded by muscle disease genes. In some embodiments, the oligonucleotide is a phosphorodiamidate morpholino oligomer.

[0018] In some embodiments, the antibody is covalently linked to the molecular payload via a cleavable linker. In some embodiments, the cleavable linker comprises a valine-citrulline dipeptide sequence.

[0019] Other aspects of this disclosure provide a method for delivering a molecular payload to cells expressing a transferrin receptor. In some embodiments, the method includes bringing the cells into contact with the complex described herein.

[0020] Other aspects of this disclosure provide methods for inhibiting the expression or activity of muscle disease genes in cells. In some embodiments, the methods involve contacting cells with the complex described herein in an amount effective in promoting the internalization of the molecular payload into the cells.

[0021] Furthermore, this specification provides a method for treating subjects with muscle diseases. In some embodiments, the method comprises administering an effective amount of the complex described herein to the subject. In some embodiments, the muscle disease is one of the diseases listed in Table 1. [Brief explanation of the drawing]

[0022] Simple description of the drawing [Figure 1] Figure 1 shows a non-limiting schematic diagram illustrating the effect of transfecting Hepa1-6 cells with antisense oligonucleotides targeting DMPK (control DMPK-ASO) on DMPK expression levels compared to vehicle transfection;

[0023] [Figure 2A]Figure 2A shows a non-limiting schematic diagram of the HIL-HPLC trace obtained during purification of a muscle-targeting complex containing an anti-transferrin receptor antibody covalently linked to a DMPK antisense oligonucleotide.

[0024] [Figure 2B] Figure 2B shows an unrestricted image of the SDS-PAGE analysis of the muscle targeting complex.

[0025] [Figure 3] Figure 3 shows a non-limiting schematic diagram illustrating the ability of the control DMPK-ASO-containing muscle targeting complex (DTX-C-008) to reduce DMPK expression levels.

[0026] [Figure 4A-B] Figures 4A-4E illustrate a non-limiting schematic diagram showing the ability of the control DMPK-ASO-containing muscle targeting complex (DTX-C-008) to reduce DMPK expression levels in mouse muscle tissue in vivo, compared to vehicle experiments. (N=3 C57Bl / 6 WT mice) [Figure 4C-D] Figures 4A-4E illustrate a non-limiting schematic diagram showing the ability of the control DMPK-ASO-containing muscle targeting complex (DTX-C-008) to reduce DMPK expression levels in mouse muscle tissue in vivo, compared to vehicle experiments. (N=3 C57Bl / 6 WT mice) [Figure 4E] Figures 4A-4E illustrate a non-limiting schematic diagram showing the ability of the control DMPK-ASO-containing muscle targeting complex (DTX-C-008) to reduce DMPK expression levels in mouse muscle tissue in vivo, compared to vehicle experiments. (N=3 C57Bl / 6 WT mice)

[0027] [Figure 5A]Figures 5A-5B illustrate a non-restrictive schematic diagram showing the tissue selectivity of the muscle-targeting complex (DTX-C-008) containing the control DMPK-ASO. The muscle-targeting complex (DTX-C-008) containing the control DMPK-ASO did not reduce DMPK expression levels in mouse brain or spleen tissue in vivo compared to vehicle experiments. (N=3 C57Bl / 6 WT mice) [Figure 5B] Figures 5A-5B illustrate a non-restrictive schematic diagram showing the tissue selectivity of the muscle-targeting complex (DTX-C-008) containing the control DMPK-ASO. The muscle-targeting complex (DTX-C-008) containing the control DMPK-ASO did not reduce DMPK expression levels in mouse brain or spleen tissue in vivo compared to vehicle experiments. (N=3 C57Bl / 6 WT mice)

[0028] [Figure 6A] Figures 6A-6F illustrate a non-limiting schematic diagram showing the ability of the control DMPK-ASO-containing muscle targeting complex (DTX-C-008) to reduce DMPK expression levels in mouse muscle tissue in vivo, compared to vehicle experiments. (N=5 C57Bl / 6 WT mice) [Figure 6B-C] Figures 6A-6F illustrate a non-limiting schematic diagram showing the ability of the control DMPK-ASO-containing muscle targeting complex (DTX-C-008) to reduce DMPK expression levels in mouse muscle tissue in vivo, compared to vehicle experiments. (N=5 C57Bl / 6 WT mice) [Figure 6D-E] Figures 6A-6F illustrate a non-limiting schematic diagram showing the ability of the control DMPK-ASO-containing muscle targeting complex (DTX-C-008) to reduce DMPK expression levels in mouse muscle tissue in vivo, compared to vehicle experiments. (N=5 C57Bl / 6 WT mice) [Figure 6F] Figures 6A-6F illustrate a non-limiting schematic diagram showing the ability of the control DMPK-ASO-containing muscle targeting complex (DTX-C-008) to reduce DMPK expression levels in mouse muscle tissue in vivo, compared to vehicle experiments. (N=5 C57Bl / 6 WT mice)

[0029] [Figure 7A] Figures 7A-7L illustrate a non-limiting schematic diagram showing the ability of a muscle-targeting complex (DTX-C-012) containing an anti-transferrin receptor antibody (15G11 antibody) and control DMPK-ASO to reduce DMPK expression levels in cynomolgus monkey muscle tissue in vivo, compared to vehicle experiments and naked DMPK ASO (control DMPK-ASO). (N=3 male cynomolgus monkeys) [Figure 7B-C] Figures 7A-7L illustrate a non-limiting schematic diagram showing the ability of a muscle-targeting complex (DTX-C-012) containing an anti-transferrin receptor antibody (15G11 antibody) and control DMPK-ASO to reduce DMPK expression levels in cynomolgus monkey muscle tissue in vivo, compared to vehicle experiments and naked DMPK ASO (control DMPK-ASO). (N=3 male cynomolgus monkeys) [Figure 7D-E] Figures 7A-7L illustrate a non-limiting schematic diagram showing the ability of a muscle-targeting complex (DTX-C-012) containing an anti-transferrin receptor antibody (15G11 antibody) and control DMPK-ASO to reduce DMPK expression levels in cynomolgus monkey muscle tissue in vivo, compared to vehicle experiments and naked DMPK ASO (control DMPK-ASO). (N=3 male cynomolgus monkeys) [Figure 7F-G] Figures 7A-7L illustrate a non-limiting schematic diagram showing the ability of a muscle-targeting complex (DTX-C-012) containing an anti-transferrin receptor antibody (15G11 antibody) and control DMPK-ASO to reduce DMPK expression levels in cynomolgus monkey muscle tissue in vivo, compared to vehicle experiments and naked DMPK ASO (control DMPK-ASO). (N=3 male cynomolgus monkeys) [Figure 7H-I]Figures 7A-7L illustrate a non-limiting schematic diagram showing the ability of a muscle-targeting complex (DTX-C-012) containing an anti-transferrin receptor antibody (15G11 antibody) and control DMPK-ASO to reduce DMPK expression levels in cynomolgus monkey muscle tissue in vivo, compared to vehicle experiments and naked DMPK ASO (control DMPK-ASO). (N=3 male cynomolgus monkeys) [Figure 7J-K] Figures 7A-7L illustrate a non-limiting schematic diagram showing the ability of a muscle-targeting complex (DTX-C-012) containing an anti-transferrin receptor antibody (15G11 antibody) and control DMPK-ASO to reduce DMPK expression levels in cynomolgus monkey muscle tissue in vivo, compared to vehicle experiments and naked DMPK ASO (control DMPK-ASO). (N=3 male cynomolgus monkeys) [Figure 7L] Figures 7A-7L illustrate a non-limiting schematic diagram showing the ability of a muscle-targeting complex (DTX-C-012) containing an anti-transferrin receptor antibody (15G11 antibody) and control DMPK-ASO to reduce DMPK expression levels in cynomolgus monkey muscle tissue in vivo, compared to vehicle experiments and naked DMPK ASO (control DMPK-ASO). (N=3 male cynomolgus monkeys)

[0030] [Figure 8A] Figures 8A-8B illustrate a non-limiting schematic diagram showing the ability of a muscle-targeting complex (DTX-C-012) containing an anti-transferrin receptor antibody (15G11 antibody) and control DMPK-ASO to reduce DMPK expression levels in cynomolgus monkey smooth muscle tissue in vivo, compared to vehicle experiments and naked DMPK ASO (control DMPK-ASO). (N=3 male cynomolgus monkeys) [Figure 8B]Figures 8A-8B illustrate a non-limiting schematic diagram showing the ability of a muscle-targeting complex (DTX-C-012) containing an anti-transferrin receptor antibody (15G11 antibody) and control DMPK-ASO to reduce DMPK expression levels in cynomolgus monkey smooth muscle tissue in vivo, compared to vehicle experiments and naked DMPK ASO (control DMPK-ASO). (N=3 male cynomolgus monkeys)

[0031] [Figure 9A] Figures 9A–9D illustrate a non-limiting schematic diagram showing the tissue selectivity of the anti-transferrin receptor antibody (15G11 antibody) and the control DMPK-ASO-containing muscle targeting complex (DTX-C-012). The DMPK-ASO-containing muscle targeting complex did not reduce DMPK expression levels in the liver, kidney, brain, or spleen tissue of cynomolgus monkeys in vivo compared to vehicle experiments. (N=3 male cynomolgus monkeys) [Figure 9B-C] Figures 9A–9D illustrate a non-limiting schematic diagram showing the tissue selectivity of the anti-transferrin receptor antibody (15G11 antibody) and the control DMPK-ASO-containing muscle targeting complex (DTX-C-012). The DMPK-ASO-containing muscle targeting complex did not reduce DMPK expression levels in the liver, kidney, brain, or spleen tissue of cynomolgus monkeys in vivo compared to vehicle experiments. (N=3 male cynomolgus monkeys) [Figure 9D] Figures 9A–9D illustrate a non-limiting schematic diagram showing the tissue selectivity of the anti-transferrin receptor antibody (15G11 antibody) and the control DMPK-ASO-containing muscle targeting complex (DTX-C-012). The DMPK-ASO-containing muscle targeting complex did not reduce DMPK expression levels in the liver, kidney, brain, or spleen tissue of cynomolgus monkeys in vivo compared to vehicle experiments. (N=3 male cynomolgus monkeys)

[0032] [Figure 10] Figure 10 shows normalized DMPK mRNA tissue expression levels across several tissue types in cynomolgus monkeys. (N=3 male cynomolgus monkeys)

[0033] [Figure 11] Figures 11A-11B illustrate a non-limiting schematic diagram showing the ability of the muscle-targeting complex (DTX-C-008) containing control DMPK-ASO to reduce DMPK expression levels in mouse muscle tissue for up to 28 days after DTX-C-008 administration, compared to vehicle experiments and naked DMPK-ASO (control DMPK-ASO).

[0034] [Figure 12] Figure 12 shows that a single dose of a muscle-targeting conjugate (DTX-C-012) containing an anti-transferrin receptor antibody (15G11 antibody) and a control DMPK-ASO was safe and tolerable in cynomolgus monkeys. (N=3 male cynomolgus monkeys)

[0035] [Figure 13A] Figures 13A-13B illustrate a non-limiting schematic diagram showing the ability of a muscle-targeting complex (DTX-C-008) containing a control DMPK-ASO to reduce DMPK expression levels in mouse muscle tissue up to 12 weeks after DTX-C008 administration, compared to vehicle treatment and to a control complex (DTX-C-007) and naked DMPK ASO (control DMPK-ASO) (N=5 C57B1 / 6 WT mice). [Figure 13B] Figures 13A-13B illustrate a non-limiting schematic diagram showing the ability of a muscle-targeting complex (DTX-C-008) containing a control DMPK-ASO to reduce DMPK expression levels in mouse muscle tissue up to 12 weeks after DTX-C008 administration, compared to vehicle treatment and to a control complex (DTX-C-007) and naked DMPK ASO (control DMPK-ASO) (N=5 C57B1 / 6 WT mice).

[0036] [Figure 14A] Figures 14A-14B illustrate a non-restrictive schematic diagram showing the targeting ability of the muscle targeting complex (DTX-C-008) containing the control DMPK-ASO against nuclear mutant DMPK RNA in a mouse model (N=6 mice). [Figure 14B] Figures 14A-14B illustrate a non-restrictive schematic diagram showing the targeting ability of the muscle targeting complex (DTX-C-008) containing the control DMPK-ASO against nuclear mutant DMPK RNA in a mouse model (N=6 mice).

[0037] [Figure 15] Figures 15A-15B illustrate a non-limiting schematic diagram showing the dose-dependent reduction ability of a muscle targeting complex (DTX-actin) containing actin-targeting oligonucleotides to the level of actin expression in muscle tissue and the functional grade of myotonia (N=2 HSALR mice).

[0038] [Figure 16A-B] Figures 16A–16C illustrate an unrestricted schematic diagram (N=10 mice) showing that the muscle-targeting complex (DTX-C-008) can significantly reduce the prolonged QTc interval in a mouse model for verifying the functional modification of arrhythmias in a DM1 cardiac model. Figure 16A shows a schematic diagram of the human DMPK construct driving the mouse model of DM1. Figure 16B shows the measured QRS interval, and Figure 16C shows the measured QTc interval. [Figure 16C] Figures 16A–16C illustrate an unrestricted schematic diagram (N=10 mice) showing that the muscle-targeting complex (DTX-C-008) can significantly reduce the prolonged QTc interval in a mouse model for verifying the functional modification of arrhythmias in a DM1 cardiac model. Figure 16A shows a schematic diagram of the human DMPK construct driving the mouse model of DM1. Figure 16B shows the measured QRS interval, and Figure 16C shows the measured QTc interval.

[0039] [Figure 17A]Figures 17A-17B illustrate a non-limiting schematic diagram (N=3) showing that a muscle-targeting complex (DTX-C-012) containing an anti-transferrin receptor antibody (15G11 antibody) and a control DMPK-ASO antisense oligonucleotide can reduce DMPK expression levels and modify the splicing of the DMPK-specific target gene (Bin1) in human cells from DM1 patients. [Figure 17B] Figures 17A-17B illustrate a non-limiting schematic diagram (N=3) showing that a muscle-targeting complex (DTX-C-012) containing an anti-transferrin receptor antibody (15G11 antibody) and a control DMPK-ASO antisense oligonucleotide can reduce DMPK expression levels and modify the splicing of the DMPK-specific target gene (Bin1) in human cells from DM1 patients.

[0040] [Figure 18] Figure 18 shows a non-limiting schematic diagram illustrating the ability of an anti-transferrin receptor antibody (15G11 antibody) muscle-targeting complex (anti-TfR-FM10) conjugated to an FM10 antisense oligonucleotide to reduce the expression levels of downstream DUX4 genes (ZSCAN4, MBD3L2, TRIM43) in human U-2 OS cells, compared to a naked FM10 antisense oligonucleotide.

[0041] [Figure 19] Figure 19 shows a non-limiting schematic diagram illustrating the dose-dependent enhancement of exon skipping in mdx mouse model muscle tissue by an anti-transferrin receptor muscle targeting complex containing a phosphorodiamidate morpholino oligomer (PMO) for exon 23 skipping.

[0042] [Figure 20A] Figures 20A-20B illustrate a non-limiting schematic diagram showing the dose-dependent increase in dystrophin in the skeletal muscle of the mdx mouse model by the anti-transferrin receptor muscle targeting complex containing the exon 23 skipping PMO. [Figure 20B]Figures 20A-20B illustrate a non-limiting schematic diagram showing the dose-dependent increase in dystrophin in the skeletal muscle of the mdx mouse model by the anti-transferrin receptor muscle targeting complex containing the exon 23 skipping PMO.

[0043] [Figure 21A] Figures 21A-21C illustrate a non-limiting schematic diagram showing the ability of an anti-transferrin receptor muscle targeting complex containing exon 23 skipping PMO to improve functional performance (Figures 21A-21B) and reduce creatine kinase levels (Figure 21C) in the mdx mouse model. [Figure 21B] Figures 21A-21C illustrate a non-limiting schematic diagram showing the ability of an anti-transferrin receptor muscle targeting complex containing exon 23 skipping PMO to improve functional performance (Figures 21A-21B) and reduce creatine kinase levels (Figure 21C) in the mdx mouse model. [Figure 21C] Figures 21A-21C illustrate a non-limiting schematic diagram showing the ability of an anti-transferrin receptor muscle targeting complex containing exon 23 skipping PMO to improve functional performance (Figures 21A-21B) and reduce creatine kinase levels (Figure 21C) in the mdx mouse model.

[0044] [Figure 22A-B] Figures 22A–22C depict non-limiting schematic diagrams showing the dose-response of selected antisense oligonucleotides in DMPK knockdown of human DM1 myotubes. A control DMPK-ASO was used as a control. All tested oligonucleotides showed DMPK knockdown activity. Statistical analysis: One-way ANOVA vs. control DMPK-ASO treatment by Tukey's HSD post-hoc test; *p<0.05, **p<0.01, ***p<0.001, ****p<0.0001. [Figure 22C]Figures 22A–22C depict non-limiting schematic diagrams showing the dose-response of selected antisense oligonucleotides in DMPK knockdown of human DM1 myotubes. A control DMPK-ASO was used as a control. All tested oligonucleotides showed DMPK knockdown activity. Statistical analysis: One-way ANOVA vs. control DMPK-ASO treatment by Tukey's HSD post-hoc test; *p<0.05, **p<0.01, ***p<0.001, ****p<0.0001.

[0045] [Figure 23] Figures 23A–23B show a non-limiting schematic diagram illustrating the dose-response of selected antisense oligonucleotides in DMPK knockdown of DM1 myotubes in non-human primate animals (NHP). A control DMPK-ASO was used as a control. All tested oligonucleotides demonstrated DMPK knockdown activity.

[0046] [Figure 24] Figure 24 is a graph showing the DMPK knockdown efficiency of conjugates containing selected anti-TfR1 antibodies covalently conjugated to antisense oligonucleotides targeting DMPK, in primate non-human animal (NHP) cells or cells from human DM1 patients (DM1).

[0047] [Figure 25] Figures 25A-25B show the binding of various anti-TfR1 antibody formats to human (Figure 25A) or crab meat (Figure 25B) transferrin receptor 1.

[0048] [Figure 26] Figure 26 shows the binding of various anti-TfR1 antibody formats to human transferrin receptor 2. An anti-TfR2 monoclonal antibody (OTI1B1) was used as a control. None of the tested antibodies bound to TfR2.

[0049] [Figure 27]Figure 27 is a graph showing the DMPK knockdown efficiency of conjugates containing the anti-TfR1 antibody described herein, covalently conjugated to an antisense oligonucleotide targeting DMPK, in primate non-human animal (NHP) cells or cells from human DM1 patients (DM1).

[0050] [Figure 28] Figures 28A and 28B show the binding of oligonucleotide-conjugated or unconjugated anti-TfR to human TfR1 (hTfR1) and cynomolgus monkey TfR1 (cTfR1), as measured by ELISA. The anti-TfR is one of those listed in Table 7. Figure 28A shows the binding of anti-TfR alone (EC50 26.6 nM) or conjugation with a DMPK-targeted oligo (EC50 8.2 nM) to hTfR1. Figure 28B shows the binding of anti-TfR alone (EC50 33.6 nM) or conjugation with a DMPK-targeted oligo (EC50 5.3 nM) to cTfR1.

[0051] [Figure 29] Figure 29 shows the quantified cellular uptake of anti-TfR Fab conjugates into rhabdomyosarcoma (RD) cells. The molecular payload of the tested conjugates was a DMPK-targeted oligonucleotide. Conjugate uptake was readily achieved by the indicated anti-TfR Fab. Conjugates with negative control Fab (anti-mouse TfR) or positive control Fab (anti-human TfR1) are also included in this assay. Cells were incubated with the indicated conjugates at a concentration of 100 nM for 4 hours. Cell uptake was measured by mean Cypher5e fluorescence. Anti-TfR is one of the conjugates listed in Table 7.

[0052] [Figure 30] Figure 30 shows DMPK expression in RD cells treated with conjugates of various concentrations containing anti-TfR antibodies (anti-TfR in Table 7) conjugated to DMPK-targeted oligonucleotides (control DMPK-ASO). The treatment duration was 3 days. Control DMPK-ASO delivered using a transfection agent was used as the control.

[0053] [Figure 31] Figure 31 shows the time-dependent serum stability of the linker used to ligate anti-TfR antibodies and molecular payloads (e.g., oligonucleotides) in various organisms after intravenous administration.

[0054] [Figure 32] Figure 32 shows DMPK expression in RD cells treated with DMPK-targeted oligonucleotides compared to cells treated with PBS. The treatment duration was 3 days. DMPK-targeted oligonucleotides were delivered to cells as free oligonucleotides (gymnotic incorporation, "free") or via transfection reagents ("trans").

[0055] [Figure 33] Figure 33 shows the results of Atp2a1 splicing correction by anti-TfR1 antibody-oligonucleotide conjugate (Ab-ASO) in a DM1 HSA-LR mouse model, measured in the gastrocnemius muscle. The anti-TfR used was RI7 217, and the oligonucleotide targets skeletal muscle actin.

[0056] [Figure 34A] Figures 34A–34C show splicing modifications of more than 30 different RNAs with respect to DM1, measured in the gastrocnemius muscle of HSA-LR mice treated with anti-TfR1 antibody-oligonucleotide (Ab-ASO) conjugates or saline. The anti-TfR used was RI7 217, and the oligonucleotide targets skeletal muscle actin. [Figure 34B] Figures 34A–34C show splicing modifications of more than 30 different RNAs with respect to DM1, measured in the gastrocnemius muscle of HSA-LR mice treated with anti-TfR1 antibody-oligonucleotide (Ab-ASO) conjugates or saline. The anti-TfR used was RI7 217, and the oligonucleotide targets skeletal muscle actin. [Figure 34C] Figures 34A–34C show splicing modifications of more than 30 different RNAs with respect to DM1, measured in the gastrocnemius muscle of HSA-LR mice treated with anti-TfR1 antibody-oligonucleotide (Ab-ASO) conjugates or saline. The anti-TfR used was RI7 217, and the oligonucleotide targets skeletal muscle actin.

[0057] [Figure 35] Figure 35 shows splicing abnormalities in the quadriceps, gastrocnemius, or tibialis anterior muscles of HSA-LR mice treated with anti-TfR1 antibody-oligonucleotide conjugates (Ab-ASO) or saline. The data represent complex splicing abnormalities measured in more than 30 RNAs, as shown in Figures 34A–34C.

[0058] [Figure 36] Figure 36 shows the myotonicity grades measured in the quadriceps, gastrocnemius, and tibialis anterior muscles of HSA-LR mice treated with saline, unconjugated oligonucleotides (ASOs), or anti-TfR1 antibody-oligonucleotide conjugates (Ab-ASOs). Myotonicity was measured by electromyography (EMG) and graded 0, 1, 2, or 3 based on the frequency of myotonic discharges.

[0059] [Figure 37] Figure 37 shows exon 51 skipping in human DMD myotubes facilitated by oligonucleotide (PMO) skipping. Cells were treated with naked PMO or PMO conjugated to anti-TfR1 Fab (Ab-PMO).

[0060] [Figure 38]Figure 38 shows the dose-dependent increase in dystrophin expression in mdx mouse quadriceps muscle after treatment with anti-mouse TfR1 (RI7 217) conjugated to an exon 23-targeted oligonucleotide (PMO), as measured by Western blotting of dystrophin with alpha-actin as a loading control. Standards were generated using pooled wild-type and pooled mdx proteins. Percentages indicate the amount of WT protein spiked into the sample.

[0061] [Figure 39] Figure 39 shows the quantification of dystrophin protein levels in the quadriceps muscle of mdx mice after treatment with various doses of anti-mouse TfR (RI7 217) conjugated to an oligonucleotide (PMO) targeting exon 23.

[0062] [Figure 40] Figure 40 shows immunofluorescence staining images of quadriceps muscles from wild-type (WT) mice treated with saline, or from mdx mice treated with saline, naked oligonucleotides, or oligonucleotides conjugated to anti-mouse TfR1 (RI7 217).

[0063] [Figure 41] Figures 41A–41B show the expression of MBD3L2, TRIM43, and ZSCAN4 transcripts in myotubes from FSHD patients treated at a wide range of concentrations with naked FM-10 (Figure 41A) or FM-10 conjugated to anti-TfR1 (Figure 41B).

[0064] [Figure 42] Figure 42 shows data illustrating that conjugates containing anti-TfR Fab' (HC of SEQ ID NO: 308 and LC of SEQ ID NO: 212) conjugated to DMD exon-skipping oligonucleotides resulted in enhanced exon skipping in DMD patient myotubes compared to naked DMD exon-skipping oligonucleotides.

[0065] [Figure 43A-B] Figures 43A–43D show the in vivo activity of conjugates containing anti-TfR Fab' (control anti-TfR Fab', or anti-TfR Fab' with HC of SEQ ID NO: 308 and LC of SEQ ID NO: 212) conjugated to a DMPK-targeted oligonucleotide, which reduces DMPK mRNA expression in mice expressing human TfR1 (hTfR1 knock-in mice). Remaining DMPK mRNA levels were measured 14 days after the first dose in the tibialis anterior muscle (Figure 43A), gastrocnemius muscle (Figure 43B), heart (Figure 43C), and diaphragm (Figure 43D) of mice. In Figures 43A–43D, p<0.05(*); p<0.01(**); p<0.001(***); p<0.0001(****). [Figure 43C-D] Figures 43A–43D show the in vivo activity of conjugates containing anti-TfR Fab' (control anti-TfR Fab', or anti-TfR Fab' with HC of SEQ ID NO: 308 and LC of SEQ ID NO: 212) conjugated to a DMPK-targeted oligonucleotide, which reduces DMPK mRNA expression in mice expressing human TfR1 (hTfR1 knock-in mice). Remaining DMPK mRNA levels were measured 14 days after the first dose in the tibialis anterior muscle (Figure 43A), gastrocnemius muscle (Figure 43B), heart (Figure 43C), and diaphragm (Figure 43D) of mice. In Figures 43A–43D, p<0.05(*); p<0.01(**); p<0.001(***); p<0.0001(****).

[0066] [Figure 44A-B] Figures 44A-44C show that conjugates containing anti-TfR, conjugated to DMPK-targeted oligonucleotides, modified splicing and reduced foci in CM-DM1-32F primary cells expressing DMPK mutant mRNA containing 380 GTG repeats. Figure 44A shows that the conjugate reduced mutant DMPK mRNA expression. Figure 44B shows that the conjugate modified BIN1 exon 11 splicing. [Figure 44C]Figure 44C shows images and quantifications of fluorescence in situ hybridization (FISH) analysis demonstrating that conjugation reduced the nuclear focus formed by mutant DMPK mRNA. [Modes for carrying out the invention]

[0067] Detailed description Aspect of this disclosure concerns the recognition that while certain molecular payloads (e.g., oligonucleotides, peptides, small molecules) may have beneficial effects on muscle cells, effectively targeting such cells is extremely difficult. As described herein, this disclosure provides a complex comprising a muscle targeting agent covalently linked to a molecular payload to overcome this challenge. In some embodiments, the complex is particularly useful for delivering a molecular payload that modulates the expression or activity of a target gene in muscle cells, for example, in subjects with or suspected of having a muscle disease. For example, in some embodiments, the complex is useful for treating subjects with rare muscle diseases, including Pompe disease, central nuclear myopathy, fibrodysplasia ossificans progressive, ataxia Friedreich, or Duchenne muscular dystrophy. In some embodiments, different molecular payloads may be used in such a complex depending on the disease being treated. For example, if the causative mutation results in a splicing defect, an oligonucleotide or other payload may be used to correct the splicing defect (e.g., an oligonucleotide that inhibits exon skipping or promotes alternative splicing). If the causative mutation results in a gain-of-function allele, oligonucleotides (e.g., RNAi, PMO, ASO-gapmer) may be used to inhibit the expression or activity of the allele. In some embodiments, for example, if the mutation results in a loss-of-function allele, the payload may include, for example, an expression construct to express the wild-type version of the allele. In some embodiments, the payload may include machinery (e.g., a guide nucleic acid, an expression construct encoding a gene-editing enzyme) to correct the causative defect, for example, by gene editing.

[0068] Further aspects of this disclosure, including the definition of terms, are provided below.

[0069] I. Definition To administer (give): As used herein, the term “administer” or “give” means to provide a complex to a subject in a physiologically and / or pharmacologically useful manner (for example, to treat a disease in the subject).

[0070] about: When used herein, the terms “approximately” or “about” refer to a value similar to the given reference value when applied to one or more values ​​of interest. In some embodiments, unless otherwise stated or evident from the context (except where such a figure exceeds 100% of a feasible value), the terms “approximately” or “about” refer to a broad range of values ​​that fall within plus or minus (greater than or less than) 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, or less than these values.

[0071] 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 an scFv fragment. In some embodiments, the antibody is a nanobody derived from an antibody of a camelid animal or a nanobody derived from a shark antibody. In some embodiments, the antibody is a bispecific antibody. In some embodiments, the antibody comprises a framework having a human germline sequence. In another embodiment, the antibody comprises a heavy chain constant region selected from the group consisting of constant regions of IgG, IgG1, IgG2, IgG2A, IgG2B, IgG2C, IgG3, IgG4, IgA1, IgA2, IgD, IgM, and IgE. In some embodiments, the antibody comprises a heavy (H) chain variable region (abbreviated herein as VH) and / or (for example, and), a light (L) chain variable region (abbreviated herein as VL). In some embodiments, the antibody comprises a constant region, for example, an Fc region. The immunoglobulin constant region refers to the heavy chain or light chain constant region. The amino acid sequences of the human IgG heavy chain and light chain constant region and their functional variations are known. With respect to 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 specific embodiments, the antibody described herein comprises a human gamma-1 CH1 domain, a CH2 domain, and / or (for example, and), a CH3 domain. In some embodiments, the amino acid sequence of the VH domain includes the amino acid sequence of the human gamma (γ) heavy chain constant region, for example, any sequence known in the art.Non-limiting examples of human constant region sequences are described in the art; see, for example, U.S. Patent No. 5,693,780 and Kabat EA et al. (1991) above. In some embodiments, the VH domain comprises an amino acid sequence that is at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, or at least 99% identical to any of the variable chain constant regions provided herein. In some embodiments, the antibody is modified, for example, via glycosylation, phosphorylation, SUMOylation, and / or (for example, 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, glypiation (GPI anchor attachment), and / or (for example, and), phosphoglycosylation. 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, the antibody is a construct comprising a polypeptide containing one or more antigen-binding fragments of the present disclosure linked to a linker polypeptide or an immunoglobulin constant region. The linker polypeptide comprises two or more amino acid residues linked by a peptide bond and is used to link one or more antigen-binding sites. Examples of linker polypeptides 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).Furthermore, antibodies may also be part of larger immunoadhesion molecules formed by covalent or noncovalent bonds between the antibody or antibody moiety and one or more other proteins or peptides. Examples of such immunoadhesion molecules include the use of streptavidin core regions to construct tetrameric scFv molecules (Kipriyanov, SM, et al. (1995) Human Antibodies and Hybridomas 6:93-101), and the use of cysteine ​​residues, marker peptides, and C-terminal polyhistidine tags to construct divalent and biotinylated scFv molecules (Kipriyanov, SM, et al. (1994) Mol.Immunol. 31:1047-1058).

[0072] CDR: As used herein, the term "CDR" refers to the complementarity-determining region within an antibody variable sequence. There are three CDRs in each of the heavy and light chain variable regions, designated as CDR1, CDR2, and CDR3 for each variable region. As used herein, the term "CDR set" refers to a group of three CDRs occurring in a single antigen-binding variable region. The precise boundaries of these CDRs are defined differently depending on the system. The system described by Kabat et al., Sequence of Proteins of Immunological Interest (National Institutes of Health, Bethesda, Md. (1987 and (1991)) not only provides a unique residue numbering system applicable to any variable region of an antibody, but also provides precise residue boundaries that define three CDRs. These CDRs are sometimes referred to as Kabat CDRs. Subportions of the CDRs may be designated as L1, L2, and L3, or H1, H2, and H3, where "L" and "H" designate the light chain and heavy chain regions, respectively. These regions are sometimes referred to as Chothia CDRs, which have boundaries that overlap with Kabat CDRs. Other boundaries that define CDRs that overlap with Kabat CDRs are described by Padlan (FASEB J.9:133-139 (1995)) and MacCallum (J Mol Biol This is described in 262(5):732-45(1996). Further CDR boundary definitions do not have to strictly adhere to one of the systems above, but may still overlap with Kabat CDRs, and may be shortened or lengthened based on predictions or experimental findings that specific residues, groups of residues, or even the entire CDR do not significantly affect antigen binding. The methods used herein may utilize CDRs defined according to any of these systems, but preferred embodiments use CDRs defined in Kabat or Chothia.

[0073] CDR-grafted antibodies: The term "CDR-conjugated antibody" refers to an antibody that contains heavy chain and light chain variable region sequences from one species, but in which one or more sequences of the VH and / or VL CDR regions are replaced with CDR sequences from another species. This includes antibodies that have mouse heavy chain and light chain variable regions, but in which one or more of the mouse CDR (e.g., CDR3) are replaced with human CDR sequences.

[0074] Chimeric antibodies: The term "chimeric antibody" refers to an antibody that contains heavy chain and light chain variable region sequences from one species and a constant region sequence from another species, such as an antibody that has mouse heavy chain and light chain variable regions linked to a human constant region.

[0075] Complementary: As used herein, the term “complementary” refers to the capacity for accurate pairing between two nucleotides or two sets of nucleotides. In particular, complementarity is a term that characterizes the degree of hydrogen bond pairing that results in a bond between two nucleotides or two sets of nucleotides. For example, if a base of an oligonucleotide at a certain position can hydrogen bond with a base of a target nucleic acid (e.g., mRNA) at a corresponding position, then the bases are considered complementary at that position. Base pairing may encompass both standard Watson-Crick base pairings and non-Watson-Crick base pairings (e.g., Wobble base pairings and Hoogsteen base pairings). For example, in some embodiments, as complementary base pairings, an adenosine-type base (A) is complementary to a thymidine-type base (T) or a uracil-type base (U), a cytosine-type base (C) is complementary to a guanosine-type base (G), and universal bases such as 3-nitropyrrole or 5-nitroindole can hybridize with any of A, C, U, or T and are considered complementary to them. Inosine (I) is also considered a universal base in the art and is considered complementary to any of A, C, U, or T.

[0076] Conserved amino acid substitutions: 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 amino acid substitution is made. Variants may be prepared according to methods for modifying polypeptide sequences known to those skilled in the art, for example, references summarizing such methods, such as 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, FMAusubel, et al., eds., John Wiley & Sons, Inc., New York. Conservative amino acid substitutions include substitutions made to amino acids in 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.

[0077] Covalently linked: As used herein, the term “covalently linked” refers to the characteristic of two or more molecules linked together by at least one covalent bond. In some embodiments, two molecules may be covalently linked together by a single bond (e.g., a disulfide bond or disulfide bridge) acting as an intermolecular linker. However, in some embodiments, two or more molecules may be covalently linked together by a molecule acting as a linker, which binds two or more molecules together through multiple covalent bonds. In some embodiments, the linker may be a cleavable linker. However, in some embodiments, the linker may be an incleavable linker.

[0078] Cross-reaction: As used herein, and in the context of targeting agents (e.g., antibodies), the term “cross-reacting” refers to the property of an agent to be able to specifically bind to one or more antigens of a similar type or class (e.g., multiple homologous, paralogous, or orthologous antigens) with similar affinity or binding activity. For example, in some embodiments, an antibody that cross-reacts to antigens of a similar type or class between humans and non-human primates (e.g., human transferrin receptors and non-human primate transferrin receptors) is capable of binding to human antigens and non-human primate antigens with similar affinity or binding activity. In some embodiments, an antibody cross-reacts to human antigens and rodent antigens of a similar type or class. In some embodiments, an antibody cross-reacts to rodent antigens of a similar type or class and non-human primate antigens. In some embodiments, an antibody cross-reacts to human antigens, non-human primate antigens, and rodent antigens of a similar type or class.

[0079] Disease alleles: As used herein, the term “disease allele” refers to any alternative form of a gene (e.g., a mutant) in which the allele is associated with a disease and / or (e.g., and) directly or indirectly contributes to or causes it. A disease allele may include, but is not limited to, insertions (e.g., disease-associated repeats described below), deletions, missense mutations, nonsense mutations, and splice site mutations, compared to a wild-type (non-disease) allele. In some embodiments, a disease allele has a loss-of-function mutation. In some embodiments, a disease allele has a gain-of-function mutation. In some embodiments, a disease allele encodes an activating mutation (e.g., encoding a constitutively active protein). In some embodiments, a disease allele is a recessive allele having a recessive phenotype. In some embodiments, a disease allele is a dominant allele having a dominant phenotype.

[0080] Disease-related recurrence: As used herein, the term “disease-associated repeat” refers to a repeating nucleotide sequence at a location in the genome in which several units of a repeating nucleotide sequence correlate with and / or (for example, and) directly or indirectly contribute to or cause a genetic disease. Each repeating unit of a disease-associated repeat may be 2, 3, 4, 5 or more nucleotides in length. For example, in some embodiments, a disease-associated repeat is a dinucleotide repeat. In some embodiments, a disease-associated repeat is a trinucleotide repeat. In some embodiments, a disease-associated repeat is a tetranucleotide repeat. In some embodiments, a disease-associated repeat is a pentanucleotide repeat. In some embodiments, a disease-associated repeat includes a CAG repeat, CTG repeat, CUG repeat, CGG repeat, CCTG repeat, or a nucleotide complement of any of these. In some embodiments, a disease-associated repeat is located in the non-coding region of a gene. However, in some embodiments, a disease-associated repeat is located in the coding region of a gene. In some embodiments, a disease-associated repeat is extended from a normal state to a length that directly or indirectly contributes to or causes a genetic disease. In some embodiments, disease-associated repeats are located in RNA (e.g., RNA transcripts). In some embodiments, disease-associated repeats are located in DNA (e.g., chromosomes, plasmids). In some embodiments, disease-associated repeats are extended to the chromosomes of germline cells. In some embodiments, disease-associated repeats are extended to the chromosomes of somatic cells. In some embodiments, disease-associated repeats are extended to numerous repeat units associated with congenital onset. In some embodiments, disease-associated repeats are extended to numerous repeat units associated with childhood onset of the disease. In some embodiments, disease-associated repeats are extended to numerous repeat units associated with adult onset of the disease.

[0081] Framework: As used herein, the term “framework” or “framework sequence” refers to the sequence remaining in the variable region after subtracting the CDRs. Since the precise definition of a CDR sequence can be determined by various systems, the meaning of a framework sequence depends on correspondingly different interpretations. The six CDRs (CDR-L1, CDR-L2, and CDR-L3 on the light chain, and CDR-H1, CDR-H2, and CDR-H3 on the heavy chain) also divide the framework regions on the light and heavy chains into four sub-regions (FR1, FR2, FR3, and FR4) on each chain, where CDR1 is located between FR1 and FR2, CDR2 between FR2 and FR3, and CDR3 between FR3 and FR4. When referred to elsewhere, framework regions that do not specify a particular sub-region as FR1, FR2, FR3, or FR4 represent the combined FRs within the variable region of a naturally occurring single immunoglobulin chain. When used herein, FR represents one of four subregions, and FR(plural) represents two or more of the four subregions containing the framework region. Human heavy and light chain acceptor sequences are known in the art. In one embodiment, acceptor sequences known in the art may be used in the antibodies disclosed herein.

[0082] Human antibodies: When used herein, the term “human antibody” is intended to encompass antibodies having variable and constant regions derived from human germline immunoglobulin sequences. The human antibodies of this disclosure may include, for example, amino acid residues not encoded by human germline immunoglobulin sequences (mutations introduced, for example, by random mutagenesis or site-directed mutagenesis in vitro, or by somatic mutation in vivo), particularly in CDRs, especially CDR3. However, when used herein, the term “human antibody” is not intended to encompass antibodies in which CDR sequences derived from the germline of another mammalian species, such as mouse, are conjugated onto a human framework sequence.

[0083] Humanized antibodies: The term “humanized antibody” refers to an antibody that contains 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 sequence and / or (e.g., and) VL sequence has been modified to be more “human-like,” i.e., more similar to human germline variable sequences. One type of humanized antibody is a CDR-conjugated antibody in which a human CDR sequence is introduced onto non-human VH and VL sequences and replaced with the corresponding non-human CDR sequence. In one embodiment, a humanized anti-transferrin receptor antibody and antigen-binding moiety are provided. Such an antibody may be produced by obtaining a mouse anti-transferrin receptor monoclonal antibody using existing hybridoma technology followed by in vitro genetic engineering for humanization (e.g., disclosed in PCT publication WO 2005 / 123126 A2 by Kasaian et al.).

[0084] Internalized cell surface receptors: As used herein, the term “internalizing cell surface receptor” refers, for example, to a cell surface receptor that is internalized by a cell in response to an external stimulus (e.g., a ligand that binds to the receptor). In some embodiments, the internalizing cell surface receptor is internalized by endocytosis. In some embodiments, the internalizing cell surface receptor is internalized by clathrin-mediated endocytosis. However, in some embodiments, the internalizing cell surface receptor is internalized by clathrin-independent pathways, such as phagocytosis, macropinocytosis, caveolae- and raft-mediated uptake, or clathrin-independent constitutive endocytosis. In some embodiments, the internalizing cell surface receptor comprises an intracellular domain, a transmembrane domain, and / or (e.g., and), an extracellular domain, which optionally further comprises a ligand-binding domain. In some embodiments, the cell surface receptor becomes internalized by the cell after ligand binding. In some embodiments, the ligand may be a muscle targeting agent or a muscle targeting antibody. In some embodiments, the internalizing cell surface receptor is a transferrin receptor.

[0085] Isolated antibodies: When used herein, "isolated antibody" is intended to refer to an antibody for which there are substantially no other antibodies with different antigen specificities (for example, an isolated antibody that specifically binds to the transferrin receptor has substantially no other antibodies that specifically bind to antigens other than the transferrin receptor). However, an isolated antibody that specifically binds to the transferrin receptor complex may have cross-reactivity to other antigens, such as transferrin receptor molecules from other species. Furthermore, an isolated antibody may be substantially free of other cellular material and / or (for example, and) chemicals.

[0086] Kabat numbering: The terms “Kabat numbering,” “Kabat definition,” and “Kabat labeling” are used interchangeably herein. These terms refer to a system of numbering amino acid residues that are recognized in the art but are more variable (i.e., highly variable) than other amino acid residues in the heavy and light chain variable regions of an antibody or its antigen-binding moiety (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, USD Department of Health and Human Services, NIH Publication No. 91-3242). In the heavy chain variable region, the hypervariable region extends from amino acid positions 31-35 for CDR1, from amino acid positions 50-65 for CDR2, and from amino acid positions 95-102 for CDR3. In the light chain variable region, the hypervariable region extends to amino acid positions 24-34 for CDR1, amino acid positions 50-56 for CDR2, and amino acid positions 89-97 for CDR3.

[0087] Molecular payload: As used herein, the term “molecular payload” refers to a molecule or species that functions to modulate a biological outcome. In some embodiments, the molecular payload is ligated to or otherwise linked to a muscle targeting agent. In some embodiments, the molecular payload is a small molecule, protein, peptide, nucleic acid, or oligonucleotide. In some embodiments, the molecular payload functions to modulate the transcription of a DNA sequence, to modulate the expression of a protein, or to modulate the activity of a protein. In some embodiments, the molecular payload is an oligonucleotide containing a chain having a region complementary to a target gene.

[0088] Muscle disease genes: As used herein, the term “muscle disease gene” refers to a gene having at least one disease allele that correlates with and / or directly or indirectly contributes to or causes muscle disease. In some embodiments, muscle disease is a rare disease, as defined, for example, by the Genetic and Rare Diseases Information Center (GARD), a program of the National Center for Advancing Translational Sciences (NCATS). In some embodiments, muscle disease is a rare disease characterized by affecting fewer than 200,000 people. In some embodiments, muscle disease is a monogenic disease. In some embodiments, muscle disease genes are the genes listed in Table 1.

[0089] Muscle targeting agents: As used herein, the term “muscle targeting agent” refers to a molecule that specifically binds to an antigen expressed on a muscle cell. The antigen in or on the muscle cell may be a membrane protein, e.g., an endogenous membrane protein or a superficial membrane protein. Typically, a muscle targeting agent specifically binds to an antigen on the muscle cell that facilitates the internalization of the muscle targeting agent (and any associated molecular payload) into the muscle cell. In some embodiments, the muscle targeting agent can specifically bind to an internalizing cell surface receptor on the muscle and be internalized into the muscle cell through receptor-mediated internalization. In some embodiments, the muscle targeting agent is a small molecule, protein, peptide, nucleic acid (e.g., an aptamer), or antibody. In some embodiments, the muscle targeting agent is linked to a molecular payload.

[0090] Muscle targeting antibodies: As used herein, the term “muscle-targeting antibody” refers to a muscle-targeting agent that is an antibody that specifically binds to an antigen found in or on muscle cells. In some embodiments, a muscle-targeting antibody specifically binds to an antigen on a muscle cell that facilitates the internalization of the muscle-targeting antibody (and any associated molecular payload) into the muscle cell. In some embodiments, a muscle-targeting antibody specifically binds to an internalized cell surface receptor present on the muscle cell. In some embodiments, a muscle-targeting antibody is an antibody that specifically binds to a transferrin receptor.

[0091] Oligonucleotides: As used herein, the term “oligonucleotide” refers to an oligomeric nucleic acid compound with a length of up to 200 nucleotides. Examples of oligonucleotides include, but are not limited to, RNAi oligonucleotides (e.g., siRNA, shRNA), microRNAs, gapmers, mixmers, phosphorodiamidite morpholinos, peptide nucleic acids, aptamers, guide nucleic acids (e.g., Cas9 guide RNA), etc. Oligonucleotides may be single-stranded or double-stranded. In some embodiments, oligonucleotides may contain one or more modified nucleotides (e.g., 2'-O-methylglycosulfate, purine, or pyrimidine modification). In some embodiments, oligonucleotides may contain one or more modified nucleotide linkages. In some embodiments, oligonucleotides may contain one or more phosphorothioate linkages, which may be in the stereochemical configuration of Rp or Sp.

[0092] Recombinant antibodies: When used herein, the term “recombinant human antibody” refers to all human antibodies prepared, expressed, created, or isolated by recombinant means, such as antibodies expressed using recombinant expression vectors transfected into host cells (as described in detail herein), 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) BioTechniques 29:128-145; Hoogenboom H., and Chames P. (2000) Immunology Today 21:371-378), antibodies isolated from human immunoglobulin gene transgenic animals (e.g., mice) (e.g., Taylor, LD, et al.) It is intended to include antibodies prepared, expressed, created, or isolated by any other means involving splicing of human immunoglobulin gene sequences with other DNA sequences, as described by 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). Such recombinant human antibodies have variable and constant regions derived from human germline immunoglobulin sequences. However, in some embodiments, such recombinant human antibodies are subjected to in vitro mutagenesis (or, when human Ig sequence transgenic animals are used, in vivo somatic mutagenesis), and therefore, although the amino acid sequences of the VH and VL regions of the recombinant antibody are derived from and related to the VH and VL sequences of the human germline, they may not be naturally present in the germline repertoire of human antibodies in vivo.One aspect of the present disclosure provides fully human antibodies capable of binding to human transferrin receptors, which may be produced using techniques well known in the art, for example, but not limited to, techniques using a human Ig phage library (e.g., disclosed in PCT publication WO 2005 / 007699 A2 by Jermutus et al.).

[0093] Complementary areas: As used herein, the term “complementary region” refers to a nucleotide sequence (e.g., a nucleotide sequence of an oligonucleotide) that is sufficiently complementary to a cognate nucleotide sequence (e.g., a nucleotide sequence of 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 fully complementary to the cognate nucleotide sequence of the target nucleic acid. However, in some embodiments, the complementary region is partially complementary to the cognate nucleotide sequence of the target nucleic acid (e.g., at least 80%, 90%, 95%, or 99% complementary). In some embodiments, the complementary region contains one, two, three, or four mismatches compared to the cognate nucleotide sequence of the target nucleic acid.

[0094] Binds specifically: As used herein, the term “specifically binds” refers to the ability of a molecule to bind to a binding partner to a degree of affinity or binding activity that the molecule can be used to distinguish the binding partner from a suitable control in a binding assay or other binding context. With respect to antibodies, the term “specifically binds” refers to the ability of an antibody to bind to a specific antigen to a degree of affinity or binding activity (for example, to the extent that it allows preferential targeting to a cell (e.g., muscle cells) through binding to the antigen, as described herein,) compared to a suitable reference antigen, or an antigen that the antibody can be used to distinguish a particular antigen from other antigens. In some embodiments, when the antibody binds to the target, 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 K less than this D When having, the antibody specifically binds to the target. In some embodiments, the antibody specifically binds to an epitope of the tip domain of the transferrin receptor, for example, the transferrin receptor.

[0095] Subject: As used herein, the term "subject" refers to a mammal. In some embodiments, the subject is a non-human primate or a rodent. In some embodiments, the subject is a human. In some embodiments, the subject is a patient / animal suspected of having or having a disease, for example, a human patient. In some embodiments, the subject is a human patient having or suspected of having a muscle disease (for example, any of the diseases provided in Table 1).

[0096] 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 by endocytosis. In some embodiments, the transferrin receptor may originate from humans (NCBI Gene ID 7037), non-human primates (e.g., NCBI Gene ID 711568 or NCBI Gene ID 102136007), or rodents (e.g., NCBI Gene ID 22042). In addition, several human transcript variants encoding various isoforms of the receptor have been characterized (e.g., those annotated with GenBank RefSeq accessions: NP_001121620.1, NP_003225.2, NP_001300894.1, and NP_001300895.1).

[0097] 2' Modified nucleoside: As used herein, the terms “2'-modified nucleoside” and “2'-modified ribonucleoside” are used interchangeably and refer to nucleosides having a sugar moiety modified at the 2' position. In some embodiments, a 2'-modified nucleoside is a 2'-4' bicyclic nucleoside, where the 2' and 4' positions of the sugar are cross-linked (e.g., by methylene, ethylene, or (S)-restricted ethyl cross-linking). In some embodiments, a 2'-modified nucleoside is a non-bicyclic 2'-modified nucleoside, where, for example, the 2' position of the sugar moiety is substituted. Non-limiting examples of 2'-modified nucleosides include: 2'-deoxy, 2'-fluoro (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-methylacetamide (2'-O-NMA), locked nucleic acids (LNA, methylene-bridged nucleic acids), ethylene-bridged nucleic acids (ENA), and (S)-restricted ethyl-bridged nucleic acids (cEt). In some embodiments, the 2'-modified nucleosides described herein are high-affinity modified nucleotides, and oligonucleotides containing 2'-modified nucleotides have increased affinity for target sequences compared to unmodified oligonucleotides. An example of the structure of a 2'-modified nucleoside is provided below: [ka]

[0098] II. Complex Provided herein are complexes comprising a targeting agent, for example, 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 antigen site, or an antibody that binds to at least two antigen sites, which may be present on the same antigen or on different antigens. The complex may be used to modulate the activity or function of at least one gene, protein, and / or (for example, and) nucleic acid. In some embodiments, the molecular payload present with the complex is responsible for the modulation of the gene, protein, and / or (for example, and) nucleic acid. The molecular payload may 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 (for example, and) nucleic acid in a cell. In some embodiments, the molecular payload is an oligonucleotide targeting a muscle disease allele in muscle cells.

[0099] In some embodiments, the complex comprises a muscle targeting agent (e.g., an anti-transferrin receptor antibody) covalently linked to a molecular payload (e.g., an antisense oligonucleotide targeting a muscle disease allele).

[0100] In some embodiments, the complex is useful for treating muscle diseases in which the molecular payload affects the activity of the corresponding gene provided in Table 1. For example, depending on the disease, the molecular payload may modulate (e.g., decrease, increase) the transcription or expression of the gene, modulate the expression of the protein encoded by the gene, or modulate the activity of the encoded protein. In some embodiments, the molecular payload is an oligonucleotide comprising a chain having a region complementary to the target gene provided in Table 1.

[0101] Table 1 - List of muscle diseases and corresponding genes Table 1-1 Table 1-2 Table 1-3

[0102] Further examples of muscle-related genes (the expression or activity of these genes may be targeted using molecular payloads provided herein) include: ACTA1, ACTN1, ADAM10, ADCY5, ADGRL2, ADGRV1, ADRA1A, AKAP6, AKT1, ALDH1A3, ALPK3, AMPH, ANK3, ANKRD17, ANKS1B, APBA1, ARRB1, ASPH, ATF2, ATF3, ATP7A, ATP8A2, BBS2, BCHE, BCL9L, BDNF, BIN1, BIN3, BMP5, BMPR1A, BORCS8 -MEF2B, BSN, BTBD9, CAB39, CACNA1A, CACNA1D, CACNA1E, CACNA2D3, CACNA2D4, CACNB2, CACNG7, CADM1, CADM2, CAPZB, CBLN2, CCN3, CDH11, CDH13, CDK5R 1, CDKN1A, CDON, CHAT, CHD2, CHN2, CHRM1, CHRNA6, CKM, CLASP1, COL11A1, COL5A1, CRP, CTNNA2, CTNNA3, CTNND2, CYFIP1, DBN1, DGKB, DGKI, DLG1, DLG2, DLGAP1, DLL4, DMD, DMPK, DNAJC5, DNM2, DNM3, DOCK4, DSCAM, DST, DTNBP1, DTYMK, EPAS1, EPHB1, ERBB4, ERC2, EYS, EZH2, FAM107A, FGF10, FOXL2, FOXO1, FOXP1, GABBR2, GABRE, GABRG3, GAD2, GAS7, GLRA2, GNA11, GNAQ, GPC6, GPM6A, GRID2, GRIK2, GRIK3, GRM1, GRM7, GSK3A, H3-3B, HDAC2, HDAC4, HDAC9, HIF 1A, HIVEP3, HLF, HOXB3, HPN, HTR3C, HTR4, IGF1, IKZF1, IRAG1, ITGA11, ITGA5, ITPR1, ITPR3, JAG1, JUP, KCNAB1, KCND3, KCNIP1, KCNIP2, KCNJ12, KCNJ5 , KCNMA1, KCNMB4, KCNN1, KDM1A, KEL, LAMA2, LGMN, LHX4, LIN7C, LRFN2, LRP1, LRRC4C, LTB4R, MAC01, MAGI2, MALAT1, MAP1B, MAP1S, MAP2, MAP2K3, MAPK8,MDGA2, MESD, MMP9, MX1, MYCBP2, MYH13, MYLK, MYLK2, MYLK3, MYO1B, MYO1D, MYO5A, MY07A, MY07B, MY09B, MY0M1, MY0Z3, MYRI P, NBN, NEB, NECTIN1, NF1, NLGN1, NLGN2, NOS1AP, NOS3, NOTCH1, NOTCH2, NRG1, NRG3, NRP2, NRXN2, P2RY6, PABPN1, PAK3, PAL LD, PAX7, PCDH15, PCDH9, PCLO, PDE1A, PDE4D, PDGFRA, PDLIM5, PDPK1, PER1, PFKM, PHACTR1, PICALM, PIK3CA, PKP4, PLCB1, P LCB4, PLEKHM3, PMP22, PPFIA2, PRKG1, PRKN, PTEN, PTN, PTPRD, PTPRT, QKI, RAPGEF2, RHOC, R1MS2, RIMS3, RIPOR2, RIT2, RNF1 65, RORA, RYR2, RYR3, SCN1A, SCN2A, SDK1, SEPTIN11, SERPINE1, SHANK2, SHISA9, SHROOM1, SIX5, SLC12A7, SLC17A8, SLC18A 2, SLC1A2, SLC1A4, SLC1A6, SLC22A3, SLC6A3, SLIT2, SMAD1, SMAD5, SMPD4, SNPH, SNTG2, SOD1, SORBS2, SOX6, SPTBN1, SQSTM This includes 1, STRA6, STXBP5, STXBP5L, SV2B, SVIL, SYNE1, SYNE2, SYT1, TACR1, TBX20, TCF4, TCTN1, TENM2, TENM4, TGFB3, TIAM1, TIAM2, TIGAR, TNF, TNNT3, TPM4, TRDN, TTN, UNC13A, UNC13B, UNC13C, UNC5C, UTRN, VCL, VWC2, VWC2L, WHRN, ZFHX3, and ZFPM2. The disease associations of these genes are:This is outlined in The DisGeNET knowledge platform for disease genomics: 2019 update, Nucleic Acids Research, 2020, Vol. 48, Database issue D845-D855, published online on November 4, 2019. Relevant content is incorporated herein by reference. DiGeNET provides a knowledge management platform that integrates and standardizes data on disease-related genes and variants from multiple sources, including scientific literature. DisGeNET covers all types of human diseases, including muscle diseases, as well as normal and abnormal traits. Therefore, complexes and molecular payloads may be configured to modulate the expression or activity of any of these genes, as described herein, for example, to treat a disease. For example, oligonucleotide payloads are provided that target the RNA (pre-mRNA or mRNA) encoded by these genes to modulate expression. In some embodiments, the oligonucleotide targets the encoded RNA for degradation, for example, via the RNAse H or RNAi pathway. In other embodiments, oligonucleotides may be configured to modulate splicing, for example, to produce exon skipping or splice switching, as in the case of DMDs.

[0103] A. Muscle targeting agents Several aspects of this disclosure provide muscle targeting agents, for example, muscle targeting agents for delivering molecular payloads to muscle cells. In some embodiments, such muscle targeting agents can bind to muscle cells, for example, via specific binding to antigens on muscle cells, and deliver the bound molecular payload to the muscle cells. In some embodiments, the molecular payload is bound to the muscle targeting agent (for example, covalently), and when the muscle targeting agent binds to an antigen on a muscle cell, it is internalized into the muscle cell, for example, via endocytosis. It should be understood that various types of muscle targeting agents may be used in accordance with this disclosure. For example, muscle targeting agents may contain, or consist of, nucleic acids (e.g., DNA or RNA), peptides (e.g., antibodies), lipids (e.g., microvesicles), or sugar moieties (e.g., polysaccharides). Exemplary muscle targeting agents are described in more detail herein, but it should be understood that the exemplary muscle targeting agents provided herein are not intended to be limiting.

[0104] Several aspects of this disclosure provide muscle targeting agents that specifically bind to antigens on muscles, such as skeletal muscle, smooth muscle, or cardiac muscle. In some embodiments, any of the muscle targeting agents provided herein bind (specifically, for example) to antigens on skeletal muscle cells, smooth muscle cells, and / or (for example, and) cardiac muscle cells.

[0105] Interaction with muscle-specific cell surface recognition elements (e.g., cell membrane proteins) can achieve both tissue localization and selective uptake into muscle cells. In some embodiments, molecules that are substrates of muscle uptake transporters are useful for delivering molecular payloads into muscle tissue. Binding to muscle surface recognition elements, followed by endocytosis, can allow even macromolecules such as antibodies to enter muscle cells. As another example, a molecular payload conjugated to transferrin or an anti-transferrin receptor antibody may be taken up by muscle cells via binding to the transferrin receptor and then endocytosed, for example, via clathrin-mediated endocytosis.

[0106] The use of muscle-targeting agents can also be useful for enriching molecular payloads (e.g., oligonucleotides) in muscle while reducing toxicity associated with the effect in other tissues. In some embodiments, muscle-targeting agents enrich bound molecular payloads in muscle cells compared to other cell types within the subject. In some embodiments, muscle-targeting agents enrich bound molecular payloads in muscle cells (e.g., skeletal muscle cells, smooth muscle cells, or cardiomyocytes) to at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 30, 40, 50, 60, 70, 80, 90, or 100 times more than in non-muscle cells (e.g., liver cells, nerve cells, blood cells, or adipocytes). In some embodiments, the toxicity of the molecular payload in a target when conjugated to a muscle targeting agent 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% when it is delivered to the target.

[0107] In some embodiments, muscle recognition elements (e.g., muscle cell antigens) may be required to achieve muscle selectivity. For example, the muscle targeter may be a small molecule that is a substrate of a muscle-specific uptake transporter. Another example is that the muscle targeter may be an antibody that enters muscle cells via transporter-mediated endocytosis. Yet another example is that the muscle targeter 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 to cell entry, receptor-based targeting may involve stimulated endocytosis to reach the desired site of action.

[0108] Myocytes included in this disclosure include, but are not limited to, skeletal muscle cells, smooth muscle cells, cardiomyocytes, myoblasts, and myocytes.

[0109] i. Muscle targeting antibodies In some embodiments, muscle targeting agents are antibodies. Generally, the high specificity of antibodies against their target antigens provides the potential to selectively target muscle cells (e.g., skeletal muscle cells, smooth muscle cells, and / or cardiomyocytes). This specificity may also limit off-target toxicity. Examples of antibodies capable of targeting surface antigens of muscle cells have been reported and are within the scope of this disclosure. For example, antibodies that target the surface of muscle cells are described in 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 KS, et al. “Expression of caveolin-3 in skeletal, cardiac, and smooth muscle 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 myosin IIb” Mol Immunol. 2003 Mar,39(13):78309; the entire contents of each of these are incorporated herein by reference.

[0110] a. Anti-transferrin receptor antibody Several aspects of this disclosure are based on the recognition that agents that bind to transferrin receptors, such as anti-transferrin receptor antibodies, can target muscle cells. Transferrin receptors are internalized cell surface receptors that transport transferrin across the cell membrane and contribute to the regulation of intracellular iron levels and homeostasis. Several aspects of this disclosure provide transferrin receptor-binding proteins capable of binding to transferrin receptors. Consequently, aspects of this disclosure provide binding proteins (e.g., antibodies) that bind to transferrin receptors. In some embodiments, binding proteins that bind to transferrin receptors are internalized into muscle cells along with any bound molecular payload. As used herein, antibodies that bind to transferrin receptors may also be interchangeably referred to as transferrin receptor antibodies, anti-transferrin receptor antibodies, or anti-TfR antibodies. Antibodies that bind to transferrin receptors, such as specifically binding antibodies, may be internalized into cells upon binding to the transferrin receptor, for example, through receptor-mediated endocytosis.

[0111] It should be understood that anti-transferrin receptor antibodies may be produced, synthesized, and / or (for example, and) derivatized using several known methodologies, e.g., library design using phage display. Exemplary methodologies are characterized in the art and incorporated by reference (Diez, P. et al. “High-throughput phage-display screening in array format”, Enzyme and microbial technology, 2015, 79, 34-41.; Christoph MH and Stanley, JR “Antibody Phage Display: Technique and Applications”, J Invest Dermatol. 2014, 134:2.; Engleman, Edgar (Ed.) “Human Hybridomas and Monoclonal Antibodies.” 1985, Springer). In other embodiments, anti-transferrin antibodies have been characterized or disclosed to date.Antibodies that specifically bind to transferrin receptors are known in the art (for example, U.S. Patent No. 4,364,934, filed 12 / 4 / 1979, “Monoclonal antibody to a human early thymocyte antigen and methods for preparing same”; U.S. Patent No. 8,409,573, filed 6 / 14 / 2006, “Anti-CD71 monoclonal antibodies and uses thereof for treating malignant tumor cells”; U.S. Patent No. 9,708,406, filed 5 / 20 / 2014, “Anti-transferrin receptor antibodies and methods of use”; U.S. Patent No. 9,611,323, filed 12 / 19 / 2014, “Low affinity blood brain barrier receptor antibodies and uses therefor”; WO 2015 / 098989, filed 12 / 24 / 2014, “Novel anti-Transferrin receptor antibody that passes through blood-brain barrier”; Schneider C. et 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 See Pharmacol. Exp. Ther., 292:1048-1052).

[0112] Provided herein are novel anti-TfR antibodies for use as muscle targeting agents (e.g., on muscle targeting complexes) in several aspects. In some aspects, the anti-TfR antibodies described herein bind to transferrin receptors with high specificity and affinity. In some aspects, the anti-TfR antibodies described herein bind specifically to any extracellular epitope of the transferrin receptor or to an epitope that will be exposed to the antibody. In some aspects, the anti-TfR antibodies provided herein bind specifically to transferrin receptors from humans, non-human primate animals, mice, rats, etc. In some aspects, the anti-TfR antibodies provided herein bind to human transferrin receptors. In some aspects, the anti-TfR antibodies described herein bind to amino acid segments of human or non-human primate animal transferrin receptors provided in SEQ ID NOs. 242-245. In some aspects, the anti-TfR antibodies described herein bind to amino acid segments corresponding to amino acids 90-96 of the human transferrin receptor as represented by SEQ ID NOs. 242, which are not in the apex domain of the transferrin receptor.

[0113] In some embodiments, 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 -13The antibodies specifically bind to TfR1 (e.g., human or non-human primate TfR1) by a binding affinity of M, or a smaller binding affinity (e.g., indicated by Kd). In some embodiments, the anti-TfR antibodies described herein bind to TfR1 by a KD in the sub-nanomole range. 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 cynoporin TfR1 (e.g., 10 -7 M, 10 -8 M, 10 -9 M, 10 -10 M, 10 -11 M, 10 -12 M, 10 -13 The antibodies do not bind to mouse TfR1 (by M or a smaller Kd). The affinity and binding kinetics of anti-TfR antibodies can be tested using any preferred method, including but not limited to biosensor technologies (e.g., OCTET or BIACORE). In some embodiments, the binding of any one of the anti-TfR antibodies described herein does not compete with or inhibit transferrin binding to TfR1. In some embodiments, the binding of any one of the anti-TfR antibodies described herein does not compete with or inhibit HFE-beta-2-microglobulin binding to TfR1.

[0114] An example of a human transferrin receptor amino acid sequence corresponding to the NCBI sequence NP_003225.2 (transferrin receptor protein 1 isoform 1, homo sapiens) is as follows: (Sequence ID 242).

[0115] Examples of non-human primate transferrin receptor amino acid sequences corresponding to the NCBI sequence NP_001244232.1 (transferrin receptor protein 1, Macaca mulatta) are as follows: (Sequence ID 243)

[0116] Examples of non-human primate transferrin receptor amino acid sequences corresponding to the NCBI sequence XP_005545315.1 (transferrin receptor protein 1, Macaca fascicularis) are as follows: (Sequence ID 244).

[0117] An example of a mouse transferrin receptor amino acid sequence corresponding to the NCBI sequence NP_001344227.1 (transferrin receptor protein 1, mus musculus) is as follows: MMDQARSAFSNLFGGEPLSYTRFSLARQVDGDNHVEMKLAADEEENADNNMKASVRKPKRFNGRLCFAAIALVIFFLIGFMSGYLGYCKRVEQKEECVKLAETEETDKSETMETEDVPTSSRLYWADLKTLLSEKLNSIEFADTIKQLSQNTYTPREAGSQKDESLAYYIENQFHEFKFSKVWRDEHYV KIQVKSSIGQNMVTIVQSNGNLDPVESPEGYVAFSKPTEVSGKLVHANFGTKKDFEELSYSVNGSLVIVRAGEITFAEKVANAQSFNAIGVLIYMDKNKFPVVEADLALFGHAHLGTGDPYTPGFPSFNHTQFPPSQSSGLPNIPVQTISRAAAEKLFGKMEGSCPARWNIDSSCKLELSQNQNVKLIVKN VLKERRILNIFGVIKGYEEPDRYVVVGAQRDALGAGVAAKSSVGTGLLLKLAQVFSDMISKDGFRPSRSIIFASWTAGDFGAVGATEWLEGYLSSLHLKAFTYINLDKVVLGTSNFKVSASPLLYTLMGKIMQDVKHPVDGKSLYRDSNWISKVEKLSFDNAAYPFLAYSGIPAVSFCFCEDADYPYLGTR LDTYEALTQKVPQLNQMVRTAAEVAGQLIIKLTHDVELNLDYEMYNSKLLSFMKDLNQFKTDIRDMGLSLQWLYSARGDYFRATSRLTTDFHNAEKTNRFVMREINDRIMKVEYHFLSPYVSPRESPFRHIFWGSGSHTLSALVENLKLRQKNITAFNETLFRNQLALATWTIQGVANALSGDIWNIDNEF (Sequence ID 245)

[0118] In some embodiments, the anti-transferrin receptor antibody comprises the following amino acid segments of the receptor: It binds to FVKIQVKDSAQNSVIIVDKNGRLVYLVENPGGYVAYSKAATVTGKLVHANFGTKKDFEDLYTPVNGSIVIVRAGKITFAEKVANAESLNAIGVLIYMDQTKFPIVNAELSFFGHAHLGTGDPYTPGFPSFNHTQFPPSRSSGLPNIPVQTISRAAAEKLFGNMEGDCPSDWKTDSTCRMVTSESKNVKLTVSNVLKE (SEQ ID NO: 246) and does not inhibit the binding interaction between the transferrin receptor and transferrin and / or (for example, and) human hemochromatosis protein (also known as HFE). In some embodiments, the anti-transferrin receptor antibodies described herein do not bind to the epitope of SEQ ID NO: 246.

[0119] Appropriate methodologies may be used, for example, through the use of recombinant DNA protocols to obtain and / or (for example, and) produce antibodies, antibody fragments, or antigen conjugates. In some embodiments, antibodies may also be produced through the generation 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 antigen of interest may be used as an immunogen of any type or entity, for example, recombinant or naturally occurring type or entity. Hybridomas are screened using standard methods, for example, ELISA screening, to find at least one hybridoma that produces an antibody targeting a specific antigen. Antibodies may also be produced through screening of protein expression libraries expressing the antibody (for example, phage display libraries). Phage display library designs may also be used in several embodiments (see, for example, U.S. Patent No. 5,223,409, 3 / 1 / 1991, “Directed evolution of novel binding proteins”; WO 1992 / 18619, 4 / 10 / 1992, “Heterodimeric receptor libraries using phagemids”; WO 1991 / 17271, 5 / 1 / 1991, “Recombinant library screening methods”; WO 1992 / 20791, 5 / 15 / 1992, “Methods for producing members of specific binding pairs”; and WO 1992 / 15679, 2 / 28 / 1992, “Improved epitope displaying phage”). In some embodiments, antigens of interest may be used to immunize non-human animals, for example, rodents or goats.In some embodiments, once antibodies have been obtained from non-human animals, they may be modified using a number of methodologies, including recombinant DNA techniques, as an option. Examples of antibody production and methodological additions are also known in the art (see, for example, Harlow et al. "Antibodies: A Laboratory Manual", Cold Spring Harbor Laboratory, 1988).

[0120] In some embodiments, the antibody is modified (e.g., modified via 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, glyciation (GPI anchor attachment), and / or (e.g., and) phosphoglycosylation. 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, the sugar molecules are present in quantities of approximately 1–10, 1–5, 5–10, 1–4, 1–3, or 2. In some embodiments, the glycosylated antibody is glycosylated whole or partially. In some embodiments, the antibody is glycosylated by chemical reaction or by enzymatic means. In some embodiments, the antibody is glycosylated in vitro or in cells (which may optionally be deficient in enzymes in the N- or O-glycosylation pathway, e.g., glycosyltransferase). In some embodiments, the antibody is functionalized with sugar or carbohydrate molecules as described in the international patent application publication WO2014065661, published on May 1, 2014, entitled “Modified antibody, antibody-conjugate and process for the preparation thereof”.

[0121] In some embodiments, the anti-TfR antibodies of this disclosure comprise the VL domain and / or (for example, and) the VH domain of any one of the anti-TfR antibodies selected from Table 2, and comprise 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 (for example, IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2), or any subclass (for example, IgG2a and IgG2b) of an immunoglobulin molecule. Non-limiting examples of human constant regions are described in the art. For example, see Kabat EA et al., (1991) above.

[0122] Table 2 provides heavy and light chain variable domains and CDR sequences of non-restricted examples of anti-TfR antibodies. Table 2. Examples of anti-TfR1 antibodies (CDR follows the IMGT® definition) [Table 2-1] [Table 2-2] [Table 2-3] [Table 2-4] [Table 2-5] [Table 2-6]

[0123] In some aspects, the anti-TfR antibodies of this disclosure comprise one or more CDR-H (e.g., CDR-H1, CDR-H2, and CDR-H3) amino acid sequences from any one of the anti-TfR antibodies selected from Table 2. In some aspects, the anti-TfR antibodies of this disclosure comprise CDR-H1, CDR-H2, and CDR-H3 provided for any one of the (elected) antibodies selected from Table 2. In some aspects, the anti-TfR antibodies of this disclosure comprise one or more CDR-L (e.g., CDR-L1, CDR-L2, and CDR-L3) amino acid sequences from any one of the anti-TfR antibodies selected from Table 2. In some aspects, the anti-TfR antibodies of this disclosure comprise CDR-L1, CDR-L2, and CDR-L3 provided for any one of the anti-TfR antibodies selected from Table 2.

[0124] In some embodiments, the anti-TfR antibodies of this disclosure include CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2, and CDR-L3, as provided for any one of the anti-TfR antibodies selected from Table 2. In some embodiments, the antibody heavy chain and light chain CDR3 domains may also play a specificly important role in the antibody's binding specificity / affinity to the antigen. Consequently, the anti-TfR antibodies of this disclosure may include at least the heavy chain and / or (for example, and) the light chain CDR3 of any one of the anti-TfR antibodies selected from Table 2.

[0125] In some examples, any of the anti-TfR antibodies of this disclosure has one or more CDR (e.g., CDR-H or CDR-L) sequences substantially similar to any of the CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2, and / or (e.g., and) CDR-L3 sequences from one of the anti-TfR antibodies selected from Table 2. In some embodiments, the positions of one or more CDRs along the VH (e.g., CDR-H1, CDR-H2, or CDR-H3) region and / or VL (e.g., CDR-L1, CDR-L2, or CDR-L3) region of the antibodies described herein may vary by one, two, three, four, five, or six amino acid positions, insofar as immunospecific binding to the transferrin receptor (e.g., human transferrin receptor) is maintained (e.g., substantially maintained, e.g., maintained by at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% compared to the binding of the original antibody from which it originates). For example, in some embodiments, the position defining the CDR of any antibody described herein may vary by one, two, three, four, five, or six amino acid positions compared to any one CDR position of any antibody described herein by shifting the N-terminal and / or C-terminal boundaries of the CDR, as long as immunospecific binding to the transferrin receptor (e.g., human transferrin receptor) is maintained (e.g., substantially maintained, e.g., maintained by at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95% compared to the binding of the original antibody from which it originates).In another embodiment, the length of one or more CDRs along the VH (e.g., CDR-H1, CDR-H2, or CDR-H3) region and / or (e.g., and) the VL (e.g., CDR-L1, CDR-L2, or CDR-L3) region of the antibody described herein may vary by 1, 2, 3, 4, 5 amino acids, or more (e.g., shorter or longer), insofar as immunospecific binding to the transferrin receptor (e.g., human transferrin receptor) is maintained (e.g., substantially maintained, e.g., at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95% compared to the binding of the original antibody from which it originates).

[0126] Consequently, in some embodiments, the CDR-L1, CDR-L2, CDR-L3, CDR-H1, CDR-H2, and / or (for example, and), CDR-H3 described herein may be shorter by a difference of 1, 2, 3, 4, 5, or more amino acids than one or more of the CDRs described herein (for example, CDRs from any of the anti-TfR antibodies selected from Table 2), as long as immunospecific binding to the transferrin receptor (for example, human transferrin receptor) is maintained (for example, substantially maintained, e.g., at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95% compared to the binding of the original antibody from which it originates). In some embodiments, the CDR-L1, CDR-L2, CDR-L3, CDR-H1, CDR-H2, and / or (for example, and), CDR-H3 described herein may be shorter by a difference of 1, 2, 3, 4, 5, or more amino acids than one or more of the CDRs described herein (for example, CDRs from any of the anti-TfR antibodies selected from Table 2), insofar as immunospecific binding to the transferrin receptor (for example, human transferrin receptor) is maintained (for example, substantially maintained, e.g., at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95% compared to the binding of the original antibody from which it is derived). In some embodiments, the amino portion of CDR-L1, CDR-L2, CDR-L3, CDR-H1, CDR-H2, and / or (for example, and), CDR-H3 described herein may be elongated by a difference of 1, 2, 3, 4, 5 amino acids, or more compared to one or more of the CDRs described herein (for example, CDRs from any of the anti-TfR antibodies selected from Table 2), insofar as immunospecific binding to the transferrin receptor (for example, human transferrin receptor) is maintained (for example, substantially maintained, e.g., at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95% compared to the binding of the original antibody from which it originates).The carboxyl portions of CDR-H2 and / or CDR-H3 may be elongated by a difference of 1, 2, 3, 4, 5 amino acids, or more, compared to one or more of the CDRs described herein (for example, CDRs from any of the anti-TfR antibodies selected from Table 2), insofar as immunospecific binding to the transferrin receptor (e.g., human transferrin receptor) is maintained (e.g., substantially maintained, e.g., at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95% compared to the binding of the original antibody from which it originates). In some embodiments, the amino portion of CDR-L1, CDR-L2, CDR-L3, CDR-H1, CDR-H2, and / or (for example, and), CDR-H3 described herein may be shortened by a difference of 1, 2, 3, 4, 5 amino acids, or more, compared to one or more of the CDRs described herein (for example, CDRs from any of the anti-TfR antibodies selected from Table 2), insofar as immunospecific binding to the transferrin receptor (for example, human transferrin receptor) is maintained (for example, substantially maintained, e.g., at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95% compared to the binding of the original antibody from which it originates). In some embodiments, the carboxyl portion of CDR-L1, CDR-L2, CDR-L3, CDR-H1, CDR-H2, and / or (for example, and), CDR-H3 described herein may be shortened by a difference of 1, 2, 3, 4, 5 amino acids, or more, compared to one or more of the CDRs described herein (for example, CDRs from any of the anti-TfR antibodies selected from Table 2), insofar as immunospecific binding to the transferrin receptor (for example, human transferrin receptor) is maintained (for example, substantially maintained, e.g., at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95% compared to the binding of the original antibody from which it originates).Either method can be used to determine whether immunospecific binding to the transferrin receptor (e.g., human transferrin receptor) is maintained, for example, using binding assays and conditions described in the art.

[0127] In some examples, any of the anti-TfR antibodies of this disclosure has one or more CDR (e.g., CDR-H or CDR-L) sequences substantially similar to any one of the anti-TfR antibodies selected from Table 2. For example, an antibody may contain one or more CDR sequences from any of the anti-TfR antibodies selected from Table 2 that 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 any of the anti-TfR antibodies selected from Table 2), insofar as immunospecific binding to the transferrin receptor (e.g., human transferrin receptor) is maintained (e.g., substantially maintained, e.g., at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% compared to the binding of the original antibody from which it originates). In some embodiments, any of the amino acid variations in any of the CDRs provided herein may be conservative variations. Conservative variations can be introduced into the CDR at positions where the residue is unlikely to be involved in interaction with the transferrin receptor protein (e.g., human transferrin receptor protein), as determined, for example, based on the crystal structure. Several 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 provided herein. In some embodiments, any of the VH domains provided herein encompasses one or more CDR-H sequences provided herein (e.g., CDR-H1, CDR-H2, and CDR-H3) (e.g., any of the CDR-H sequences provided in any one of the anti-TfR antibodies selected from Table 2). In some embodiments, any of the VL domains provided herein encompass one or more CDR-L sequences provided herein (e.g., CDR-L1, CDR-L2, and CDR-L3) (e.g., any of the CDR-L sequences provided in any one of the anti-TfR antibodies selected from Table 2).

[0128] In some embodiments, the anti-TfR antibodies of this disclosure encompass any antibody that also includes the heavy chain variable domain and / or (for example, and) the light chain variable domain of any one of the anti-TfR antibodies selected from Table 2, as well as their variants. In some embodiments, the anti-TfR antibodies of this disclosure also encompass any antibody that also includes the heavy chain variable and light chain variable pair of any one of the anti-TfR antibodies selected from Table 2.

[0129] Aspects of this disclosure provide anti-TfR antibodies having a heavy chain variable (VH) domain amino acid sequence and / or (for example, and) a light chain variable (VL) domain amino acid sequence homologous to any of the anti-TfR antibodies described herein. In some embodiments, an anti-TfR antibody contains a heavy chain variable sequence or a light chain variable sequence that is at least 75% (for example, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the heavy chain variable sequence and / or (for example, and) any light chain variable sequence of any anti-TfR antibody, such as any one of the anti-TfR antibodies selected from Table 2. In some embodiments, the homologous heavy chain variable and / or light chain variable amino acid sequences are within the range of any of the 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 within a range of heavy chain variable sequences and / or (e.g., and) light chain variable sequences that exclude any of the CDR sequences provided herein. In some embodiments, any of the anti-TfR antibodies provided herein includes a heavy chain variable sequence and a light chain variable sequence that are at least 75%, 80%, 85%, 90%, 95%, 98%, or 99% identical to the framework sequence of any of the anti-TfR antibodies selected from Table 2.

[0130] In some embodiments, the anti-TfR antibody of the present disclosure comprises heavy chain variable domains CDR-H1, CDR-H2, and CDR-H3 having the amino acid sequence of SEQ ID NO: 7. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises light chain variable domains CDR-L1, CDR-L2, and CDR-L3 having the amino acid sequence of SEQ ID NO: 8.

[0131] In some embodiments, the anti-TfR antibody of the present disclosure includes 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.

[0132] In some embodiments, the anti-TfR antibodies of the present disclosure include: CDR-H1 having the amino acid sequence of SEQ ID NO: 1; CDR-H2 having the amino acid sequence of SEQ ID NO: 2 with an amino acid substitution at position 5 (for example, asparagine at position 5 is substituted with one of the following, for example, 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. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of this disclosure include: 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-L2 as represented by SEQ ID NO: 2 is N5T or N5S.

[0133] In some embodiments, the anti-TfR antibodies of the present disclosure include: CDR-H1 having the amino acid sequence of SEQ ID NO: 1; CDR-H2 having the amino acid sequence of SEQ ID NO: 262 or SEQ ID NO: 80; and CDR-H3 having the amino acid sequence of SEQ ID NO: 3. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure include: 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 aspects, the anti-TfR antibodies of the present disclosure include CDR-H1, CDR-H2, and CDR-H3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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: 262, or SEQ ID NO: 80, and CDR-H3 having the amino acid sequence of SEQ ID NO: 3. When "together" is used anywhere in the present disclosure, it means that the total number of amino acid variations in all three heavy chain CDRs is within the defined range. Alternatively or in addition (e.g., in addition), the anti-TfR receptor antibodies of the present disclosure include CDR-L1, CDR-L2, and CDR-L3, which together contain only 5 amino acid variations (e.g., only 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.

[0135] In some embodiments, the anti-TfR antibody of the present disclosure comprises CDR-H1, CDR-H2, and CDR-H3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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: 262, or SEQ ID NO: 80, and CDR-H3 having the amino acid sequence of SEQ ID NO: 3. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises CDR-L1, CDR-L2, and CDR-L3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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.

[0136] In some aspects, the anti-TfR antibodies of the present disclosure include: CDR-H1 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 1; CDR-H2 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 2, SEQ ID NO: 262, or SEQ ID NO: 80; and / or (e.g., and) CDR-H3 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 3. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure include: CDR-L1 having only three amino acid variations (for example, only three, two, or one amino acid variation) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 4; CDR-L2 having only three amino acid variations (for example, only three, two, or one amino acid variation) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 5; and / or (for example, and) CDR-L3 having only three amino acid variations (for example, only three, two, or one amino acid variation) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 6.

[0137] In some embodiments, the anti-TfR antibody of the present disclosure comprises VH having the amino acid sequence of SEQ ID NO: 7. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises VL having the amino acid sequence of SEQ ID NO: 8.

[0138] In some embodiments, the anti-TfR antibody of the present disclosure contains VH with only 25 amino acid variations (for example, only 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 VH as represented by SEQ ID NO: 7. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure includes a VL containing only 25 amino acid variations (for example, only 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid variation) when compared to a VL as represented by SEQ ID NO: 8.

[0139] In some embodiments, the anti-TfR antibody of the present disclosure comprises a VH having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) the same amino acid sequence as VH as represented by SEQ ID NO: 7. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises a VL having at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) the same amino acid sequence as VL as represented by SEQ ID NO: 8.

[0140] In some embodiments, the anti-TfR antibody of the present disclosure comprises VH as represented by SEQ ID NO: 7 and has an amino acid substitution at position 55 (for example, asparagine at position 55 is substituted with one of the following, for example, 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 in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises VL as represented by SEQ ID NO: 8. In some embodiments, the amino acid substitution at position 55 of VH as represented by SEQ ID NO: 7 is N55T or N55S. When VH as represented by SEQ ID NO: 7 is annotated using the Kabat numbering system, amino acid position 55 of SEQ ID NO: 7 is assigned the number 54. When N54T or N54S is referred to herein, it refers to a mutation using the Kabat numbering system.

[0141] In some embodiments, the anti-TfR antibody of the present disclosure comprises a VH having an amino acid substitution at position 64 compared to SEQ ID NO: 7. In some embodiments, the anti-TfR antibody of the present disclosure comprises a VH having Met at the position corresponding to position 64 in SEQ ID NO: 7. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises a VL having an amino acid sequence that is at least 80% (for example, 80%, 85%, 90%, 95%, 98%, 99%, or 100%) identical to the VL as represented by SEQ ID NO: 8.

[0142] In some embodiments, the anti-TfR antibody of the present disclosure comprises heavy chain variable domains CDR-H1, CDR-H2, and CDR-H3 having the amino acid sequence of SEQ ID NO: 15. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises light chain variable domains CDR-L1, CDR-L2, and CDR-L3 having the amino acid sequence of SEQ ID NO: 16.

[0143] In some embodiments, the anti-TfR antibodies of the present disclosure include 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.

[0144] In some aspects, the anti-TfR antibodies of the Disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the Disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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.

[0145] In some embodiments, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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.

[0146] In some aspects, the anti-TfR antibodies of the present disclosure include: CDR-H1 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 9; CDR-H2 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 10; and / or CDR-H3 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 11. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure include: CDR-L1 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 12; CDR-L2 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 13; and / or (for example, and) CDR-L3 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 14.

[0147] In some embodiments, the anti-TfR antibody of the present disclosure comprises VH, which contains the amino acid sequence of SEQ ID NO: 15. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises VL, which contains the amino acid sequence of SEQ ID NO: 16.

[0148] In some embodiments, the anti-TfR antibody of the present disclosure comprises VH containing only 25 amino acid variations (e.g., only 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 VH as represented by SEQ ID NO: 15. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises VL containing only 25 amino acid variations (e.g., only 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 VL as represented by SEQ ID NO: 16.

[0149] In some embodiments, the anti-TfR antibody of the present disclosure comprises a VH having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VH as represented by SEQ ID NO: 15. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises a VL having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL as represented by SEQ ID NO: 16.

[0150] In some embodiments, the anti-TfR antibody of the present disclosure comprises heavy chain variable domains CDR-H1, CDR-H2, and CDR-H3 having the amino acid sequence of SEQ ID NO: 23. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises light chain variable domains CDR-L1, CDR-L2, and CDR-L3 having the amino acid sequence of SEQ ID NO: 24.

[0151] In some embodiments, the anti-TfR antibody of the present disclosure includes 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.

[0152] In some embodiments, the anti-TfR antibodies of the present disclosure include: CDR-H1 having the amino acid sequence of SEQ ID NO: 17 with an amino acid substitution at position 8 (for example, the cysteine ​​at position 8 is substituted with one 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. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of this disclosure include: 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. In some embodiments, the amino acid substitution at position 8 of CDR-H1 as represented by SEQ ID NO: 17 is C8D or C8Y.

[0153] In some embodiments, the anti-TfR antibodies of the present disclosure include: CDR-H1 having the amino acid sequence of SEQ ID NO: 266 or SEQ ID NO: 268; 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 in addition (for example, in addition), the anti-TfR antibodies of the present disclosure include: 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 aspects, the anti-TfR antibodies of the Disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 17, SEQ ID NO: 266, or SEQ ID NO: 268, 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 in addition (e.g., in addition), the anti-TfR antibodies of the Disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together contain only 5 amino acid variations (e.g., only 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.

[0155] In some embodiments, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together are at least 75% (for example, 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to CDR-H1 having the amino acid sequence of SEQ ID NO: 17, SEQ ID NO: 266, or SEQ ID NO: 268, 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 in addition (for example, in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together are at least 75% (for example, 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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.

[0156] In some embodiments, the anti-TfR antibodies of the present disclosure include: CDR-H1 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 17, SEQ ID NO: 266, or SEQ ID NO: 268; CDR-H2 having only three amino acid variations (e.g., only three, two, or one 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 only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 19. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure include: CDR-L1 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 20; CDR-L2 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 21; and / or (for example, and) CDR-L3 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 22.

[0157] In some embodiments, the anti-TfR antibody of the present disclosure comprises VH having the amino acid sequence of SEQ ID NO: 23. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises VL having the amino acid sequence of SEQ ID NO: 24.

[0158] In some embodiments, the anti-TfR antibody of the present disclosure contains VH with only 25 amino acid variations (e.g., only 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 VH as represented by SEQ ID NO: 23. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure includes a VL containing only 25 amino acid variations (for example, only 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 as represented in SEQ ID NO: 24.

[0159] In some embodiments, the anti-TfR antibody of the present disclosure comprises a VH having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VH as represented by SEQ ID NO: 23. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises a VL having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL as represented by SEQ ID NO: 24.

[0160] In some embodiments, the anti-TfR antibody of the present disclosure comprises VH as represented by SEQ ID NO: 23, having an amino acid substitution at position 33 (for example, the cysteine ​​at position 33 is substituted with any one 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 in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises VL as represented by SEQ ID NO: 24. In some embodiments, the amino acid substitution at position 33 of VH as represented by SEQ ID NO: 23 is C33D or C33Y. When VH is annotated by the Kabat numbering system as represented by SEQ ID NO: 23, amino acid 33 of SEQ ID NO: 23 is assigned the number 33.

[0161] In some embodiments, the anti-TfR antibody of the present disclosure comprises heavy chain variable domains CDR-H1, CDR-H2, and CDR-H3 having the amino acid sequence of SEQ ID NO: 31. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises light chain variable domains CDR-L1, CDR-L2, and CDR-L3 having the amino acid sequence of SEQ ID NO: 32.

[0162] In some embodiments, the anti-TfR antibodies of the present disclosure include 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.

[0163] In some aspects, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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.

[0164] In some embodiments, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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.

[0165] In some aspects, the anti-TfR antibodies of the present disclosure include: CDR-H1 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 25; CDR-H2 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 26; and / or CDR-H3 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 27. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure include: CDR-L1 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 28; CDR-L2 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 29; and / or (for example, and) CDR-L3 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 30.

[0166] In some embodiments, the anti-TfR antibody of the present disclosure comprises VH having the amino acid sequence of SEQ ID NO: 31. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises VL having the amino acid sequence of SEQ ID NO: 32.

[0167] In some embodiments, the anti-TfR antibody of the present disclosure contains VH with only 25 amino acid variations (e.g., only 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 VH as represented by SEQ ID NO: 31. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure includes a VL containing only 25 amino acid variations (for example, only 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 as represented in SEQ ID NO: 32.

[0168] In some embodiments, the anti-TfR antibody of the present disclosure comprises a VH having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VH as represented by SEQ ID NO: 31. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises a VL having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL as represented by SEQ ID NO: 32.

[0169] In some embodiments, the anti-TfR antibody of the present disclosure comprises heavy chain variable domains CDR-H1, CDR-H2, and CDR-H3 having the amino acid sequence of SEQ ID NO: 39. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises light chain variable domains CDR-L1, CDR-L2, and CDR-L3 having the amino acid sequence of SEQ ID NO: 40.

[0170] In some embodiments, the anti-TfR antibodies of the present disclosure include 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.

[0171] In some aspects, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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.

[0172] In some embodiments, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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.

[0173] In some aspects, the anti-TfR antibodies of the present disclosure include: CDR-H1 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 33; CDR-H2 having only three amino acid variations (e.g., only three, two, or one 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 only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 35. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure include: CDR-L1 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 36; CDR-L2 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 37; and / or (for example, and) CDR-L3 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 38.

[0174] In some embodiments, the anti-TfR antibody of the present disclosure comprises VH, which comprises the amino acid sequence of SEQ ID NO: 39. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises VL, which comprises the amino acid sequence of SEQ ID NO: 40.

[0175] In some embodiments, the anti-TfR antibody of the present disclosure contains VH with only 25 amino acid variations (e.g., only 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 VH as represented by SEQ ID NO: 39. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure includes a VL containing only 25 amino acid variations (for example, only 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 as represented by SEQ ID NO: 40.

[0176] In some embodiments, the anti-TfR antibody of the present disclosure comprises a VH having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VH as represented by SEQ ID NO: 39. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises a VL having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL as represented by SEQ ID NO: 40.

[0177] In some embodiments, the anti-TfR antibody of the present disclosure comprises heavy chain variable domains CDR-H1, CDR-H2, and CDR-H3 having the amino acid sequence of SEQ ID NO: 47. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises light chain variable domains CDR-L1, CDR-L2, and CDR-L3 having the amino acid sequence of SEQ ID NO: 48.

[0178] In some embodiments, the anti-TfR antibody of the present disclosure includes 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.

[0179] In some aspects, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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.

[0180] In some embodiments, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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.

[0181] In some aspects, the anti-TfR antibodies of the present disclosure include: CDR-H1 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 41; CDR-H2 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 42; and / or CDR-H3 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 43. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure include: CDR-L1 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 44; CDR-L2 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 45; and / or (for example, and) CDR-L3 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 46.

[0182] In some embodiments, the anti-TfR antibody of the present disclosure comprises VH, which contains the amino acid sequence of SEQ ID NO: 47. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises VL, which contains the amino acid sequence of SEQ ID NO: 48.

[0183] In some embodiments, the anti-TfR antibody of the present disclosure contains VH with only 25 amino acid variations (e.g., only 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 VH as represented by SEQ ID NO: 47. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure includes a VL containing only 25 amino acid variations (for example, only 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 as represented by SEQ ID NO: 48.

[0184] In some embodiments, the anti-TfR antibody of the present disclosure comprises a VH having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VH as represented by SEQ ID NO: 47. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises a VL having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL as represented by SEQ ID NO: 48.

[0185] In some embodiments, the anti-TfR antibody of the present disclosure comprises heavy chain variable domains CDR-H1, CDR-H2, and CDR-H3 having the amino acid sequence of SEQ ID NO: 54. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises light chain variable domains CDR-L1, CDR-L2, and CDR-L3 having the amino acid sequence of SEQ ID NO: 55.

[0186] In some embodiments, the anti-TfR antibodies of the present disclosure comprise a CDR-H1 having the amino acid sequence of SEQ ID NO: 49 (according to the IMGT definition system), a CDR-H2 having the amino acid sequence of SEQ ID NO: 50 (according to the IMGT definition system), a CDR-H3 having the amino acid sequence of SEQ ID NO: 51 (according to the IMGT definition system), a CDR-L1 having the amino acid sequence of SEQ ID NO: 52 (according to the IMGT definition system), a CDR-L2 having the amino acid sequence of SEQ ID NO: 29 (according to the IMGT definition system), and a CDR-L3 having the amino acid sequence of SEQ ID NO: 53 (according to the IMGT definition system).

[0187] In some embodiments, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together contain a total of only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variations) 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together contain a total of only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variations) 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.

[0188] In some embodiments, the anti-TfR antibodies of the present disclosure include CDR-H1, CDR-H2, and CDR-H3, which are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical, in combination, 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure include CDR-L1, CDR-L2, and CDR-L3, which are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical, in combination, 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.

[0189] In some aspects, the anti-TfR antibodies of the present disclosure include: CDR-H1 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 49; CDR-H2 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 50; and / or CDR-H3 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 51. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure include: CDR-L1 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 52; CDR-L2 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 29; and / or (for example, and) CDR-L3 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 53.

[0190] In some embodiments, the anti-TfR antibody of the present disclosure comprises VH, which comprises the amino acid sequence of SEQ ID NO: 54. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises VL, which comprises the amino acid sequence of SEQ ID NO: 55.

[0191] In some embodiments, the anti-TfR antibody of the present disclosure contains VH with only 25 amino acid variations (e.g., only 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 VH as represented by SEQ ID NO: 54. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure includes a VL containing only 25 amino acid variations (for example, only 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 a VL as represented by SEQ ID NO: 55.

[0192] In some embodiments, the anti-TfR antibody of the present disclosure comprises a VH having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VH as represented by SEQ ID NO: 54. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises a VL having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL as represented by SEQ ID NO: 55.

[0193] In some embodiments, the anti-TfR antibody of the present disclosure comprises heavy chain variable domains CDR-H1, CDR-H2, and CDR-H3 having the amino acid sequence of SEQ ID NO: 62. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises light chain variable domains CDR-L1, CDR-L2, and CDR-L3 having the amino acid sequence of SEQ ID NO: 63.

[0194] In some embodiments, the anti-TfR antibody of the present disclosure includes 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.

[0195] In some aspects, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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.

[0196] In some embodiments, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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.

[0197] In some aspects, the anti-TfR antibodies of the present disclosure include: CDR-H1 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 56; CDR-H2 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 57; and / or CDR-H3 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 58. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure include: CDR-L1 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 59; CDR-L2 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 60; and / or (for example, and) CDR-L3 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 61.

[0198] In some embodiments, the anti-TfR antibody of the present disclosure comprises VH, which comprises the amino acid sequence of SEQ ID NO: 62. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises VL, which comprises the amino acid sequence of SEQ ID NO: 63.

[0199] In some embodiments, the anti-TfR antibody of the present disclosure contains VH with only 25 amino acid variations (e.g., only 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 VH as represented by SEQ ID NO: 62. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure includes a VL containing only 25 amino acid variations (for example, only 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 as represented by SEQ ID NO: 63.

[0200] In some embodiments, the anti-TfR antibody of the present disclosure comprises a VH having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VH as represented by SEQ ID NO: 62. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises a VL having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL as represented by SEQ ID NO: 63.

[0201] In some embodiments, the anti-TfR antibody of the present disclosure comprises heavy chain variable domains CDR-H1, CDR-H2, and CDR-H3 having the amino acid sequence of SEQ ID NO: 70. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises light chain variable domains CDR-L1, CDR-L2, and CDR-L3 having the amino acid sequence of SEQ ID NO: 71.

[0202] In some embodiments, the anti-TfR antibody of the present disclosure includes 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.

[0203] In some aspects, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) compared to 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) compared to 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 antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to 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.

[0205] In some embodiments, the anti-TfR antibodies of the present disclosure include: CDR-H1 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 64; CDR-H2 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 65; and / or CDR-H3 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 66. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure include: CDR-L1 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 67; CDR-L2 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 68; and / or (for example, and) CDR-L3 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 69.

[0206] In some embodiments, the anti-TfR antibody of the present disclosure comprises VH containing the amino acid sequence of SEQ ID NO: 70. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises VL containing the amino acid sequence of SEQ ID NO: 71.

[0207] In some embodiments, the anti-TfR antibodies of the present disclosure include a VH containing a variation of only 25 amino acids (e.g., a variation of only 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) compared to the VH as set forth in SEQ ID NO: 70. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure include a VL containing a variation of only 25 amino acids (e.g., a variation of only 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) compared to the VL as set forth in SEQ ID NO: 71.

[0208] In some embodiments, the anti-TfR antibodies of the present disclosure include a VH containing an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VH as set forth in SEQ ID NO: 70. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure include a VL containing an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL as set forth in SEQ ID NO: 71.

[0209] In some embodiments, the anti-TfR antibodies of the present disclosure include CDR-H1, CDR-H2, and CDR-H3 of the heavy chain variable domain having the amino acid sequence of SEQ ID NO: 77. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure include CDR-L1, CDR-L2, and CDR-L3 of the light chain variable domain having the amino acid sequence of SEQ ID NO: 78.

[0210] In some embodiments, the anti-TfR antibody of the present disclosure includes 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.

[0211] In some aspects, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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.

[0212] In some embodiments, the anti-TfR antibodies of the Disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the Disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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.

[0213] In some aspects, the anti-TfR antibodies of the present disclosure include: CDR-H1 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 72; CDR-H2 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 73; and / or CDR-H3 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 74. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure include: CDR-L1 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 75; CDR-L2 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 45; and / or (for example, and) CDR-L3 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 76.

[0214] In some embodiments, the anti-TfR antibody of the present disclosure comprises VH, which comprises the amino acid sequence of SEQ ID NO: 77. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises VL, which comprises the amino acid sequence of SEQ ID NO: 78.

[0215] In some embodiments, the anti-TfR antibody of the present disclosure contains VH with only 25 amino acid variations (e.g., only 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 VH as represented by SEQ ID NO: 77. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure includes a VL containing only 25 amino acid variations (for example, only 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 as represented by SEQ ID NO: 78.

[0216] In some embodiments, the anti-TfR antibody of the present disclosure comprises a VH having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VH as represented by SEQ ID NO: 77. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises a VL having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL as represented by SEQ ID NO: 78.

[0217] In some embodiments, the anti-TfR antibody of the present disclosure comprises heavy chain variable domains CDR-H1, CDR-H2, and CDR-H3 having the amino acid sequence of SEQ ID NO: 85. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises light chain variable domains CDR-L1, CDR-L2, and CDR-L3 having the amino acid sequence of SEQ ID NO: 86.

[0218] In some embodiments, the anti-TfR antibody of the present disclosure includes 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.

[0219] In some aspects, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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.

[0220] In some embodiments, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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.

[0221] In some aspects, the anti-TfR antibodies of the present disclosure include: CDR-H1 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 79; CDR-H2 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 80; and / or CDR-H3 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 81. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure include: CDR-L1 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 82; CDR-L2 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 83; and / or (for example, and) CDR-L3 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 84.

[0222] In some embodiments, the anti-TfR antibody of the present disclosure comprises VH, which comprises the amino acid sequence of SEQ ID NO: 85. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises VL, which comprises the amino acid sequence of SEQ ID NO: 86.

[0223] In some embodiments, the anti-TfR antibody of the present disclosure contains VH with only 25 amino acid variations (e.g., only 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 VH as represented by SEQ ID NO: 85. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure includes a VL containing only 25 amino acid variations (for example, only 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 as represented by SEQ ID NO: 86.

[0224] In some embodiments, the anti-TfR antibody of the present disclosure comprises a VH having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VH as represented by SEQ ID NO: 85. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises a VL having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL as represented by SEQ ID NO: 86.

[0225] In some embodiments, the anti-TfR antibody of the present disclosure comprises heavy chain variable domains CDR-H1, CDR-H2, and CDR-H3 having the amino acid sequence of SEQ ID NO: 89. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises light chain variable domains CDR-L1, CDR-L2, and CDR-L3 having the amino acid sequence of SEQ ID NO: 90.

[0226] In some embodiments, the anti-TfR antibodies of the present disclosure include 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.

[0227] In some aspects, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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.

[0228] In some embodiments, the anti-TfR antibodies of the Disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the Disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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.

[0229] In some aspects, the anti-TfR antibodies of the present disclosure include: CDR-H1 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 72; CDR-H2 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 87; and / or CDR-H3 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 74. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure include: CDR-L1 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 75; CDR-L2 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 45; and / or (for example, and) CDR-L3 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 88.

[0230] In some embodiments, the anti-TfR antibody of the present disclosure comprises VH, which comprises the amino acid sequence of SEQ ID NO: 89. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises VL, which comprises the amino acid sequence of SEQ ID NO: 90.

[0231] In some embodiments, the anti-TfR antibody of the present disclosure contains VH with only 25 amino acid variations (e.g., only 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 VH as represented by SEQ ID NO: 89. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure includes a VL containing only 25 amino acid variations (for example, only 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 as represented by SEQ ID NO: 90.

[0232] In some embodiments, the anti-TfR antibody of the present disclosure comprises a VH having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VH as represented by SEQ ID NO: 89. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises a VL having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL as represented by SEQ ID NO: 90.

[0233] In some embodiments, the anti-TfR antibody of the present disclosure comprises heavy chain variable domains CDR-H1, CDR-H2, and CDR-H3 having the amino acid sequence of SEQ ID NO: 97. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises light chain variable domains CDR-L1, CDR-L2, and CDR-L3 having the amino acid sequence of SEQ ID NO: 98.

[0234] In some embodiments, the anti-TfR antibody of the present disclosure includes 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.

[0235] In some aspects, the anti-TfR antibodies of the Disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the Disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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.

[0236] In some embodiments, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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.

[0237] In some aspects, the anti-TfR antibodies of the present disclosure include: CDR-H1 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 91; CDR-H2 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 92; and / or CDR-H3 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 93. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure include: CDR-L1 having only three amino acid variations (for example, only three, two, or one amino acid variations) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 94; CDR-L2 having only three amino acid variations (for example, only three, two, or one amino acid variations) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 95; and / or (for example, and) CDR-L3 having only three amino acid variations (for example, only three, two, or one amino acid variations) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 96.

[0238] In some embodiments, the anti-TfR antibody of the present disclosure comprises VH having the amino acid sequence of SEQ ID NO: 97. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises VL having the amino acid sequence of SEQ ID NO: 98.

[0239] In some embodiments, the anti-TfR antibody of the present disclosure comprises VH containing only 25 amino acid variations (e.g., only 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 VH as represented by SEQ ID NO: 97. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises VL containing only 25 amino acid variations (e.g., only 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 VL as represented by SEQ ID NO: 98.

[0240] In some embodiments, the anti-TfR antibody of the present disclosure comprises a VH having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VH as represented by SEQ ID NO: 97. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises a VL having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL as represented by SEQ ID NO: 98.

[0241] In some embodiments, the anti-TfR antibody of the present disclosure comprises heavy chain variable domains CDR-H1, CDR-H2, and CDR-H3 having the amino acid sequence of SEQ ID NO: 104. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises light chain variable domains CDR-L1, CDR-L2, and CDR-L3 having the amino acid sequence of SEQ ID NO: 105.

[0242] In some aspects, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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.

[0243] In some embodiments, the anti-TfR antibodies of the Disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the Disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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.

[0244] In some aspects, the anti-TfR antibodies of the present disclosure include: CDR-H1 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 99; CDR-H2 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 100; and / or CDR-H3 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 101. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure include: CDR-L1 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 102; CDR-L2 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 60; and / or (for example, and) CDR-L3 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 103.

[0245] In some embodiments, the anti-TfR antibody of the present disclosure comprises VH, which contains the amino acid sequence of SEQ ID NO: 104. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises VL, which contains the amino acid sequence of SEQ ID NO: 105.

[0246] In some embodiments, the anti-TfR antibody of the present disclosure comprises a VH containing only 25 amino acid variations (e.g., only 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 VH as represented by SEQ ID NO: 104. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises a VL containing only 25 amino acid variations (e.g., only 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 VL as represented by SEQ ID NO: 105.

[0247] In some embodiments, the anti-TfR antibody of the present disclosure comprises a VH having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VH as represented by SEQ ID NO: 104. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises a VL having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL as represented by SEQ ID NO: 105.

[0248] In some embodiments, the anti-TfR antibody of the present disclosure comprises heavy chain variable domains CDR-H1, CDR-H2, and CDR-H3 having the amino acid sequence of SEQ ID NO: 112. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises light chain variable domains CDR-L1, CDR-L2, and CDR-L3 having the amino acid sequence of SEQ ID NO: 113.

[0249] In some embodiments, the anti-TfR antibodies of the present disclosure include 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.

[0250] In some aspects, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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.

[0251] In some embodiments, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together are at least 75% (for example, 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together are at least 75% (for example, 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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.

[0252] In some aspects, the anti-TfR antibodies of the present disclosure include: CDR-H1 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 106; CDR-H2 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 107; and / or CDR-H3 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 108. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure include: CDR-L1 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 109; CDR-L2 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 110; and / or (for example, and) CDR-L3 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 111.

[0253] In some embodiments, the anti-TfR antibody of the present disclosure comprises VH, which comprises the amino acid sequence of SEQ ID NO: 112. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises VL, which comprises the amino acid sequence of SEQ ID NO: 113.

[0254] In some embodiments, the anti-TfR antibody of the present disclosure comprises a VH containing only 25 amino acid variations (e.g., only 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 VH as represented by SEQ ID NO: 112. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises a VL containing only 25 amino acid variations (e.g., only 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 VL as represented by SEQ ID NO: 113.

[0255] In some embodiments, the anti-TfR antibody of the present disclosure comprises a VH having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VH as represented by SEQ ID NO: 112. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises a VL having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL as represented by SEQ ID NO: 113.

[0256] In some embodiments, the anti-TfR antibody of the present disclosure comprises heavy chain variable domains CDR-H1, CDR-H2, and CDR-H3 having the amino acid sequence of SEQ ID NO: 117. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises light chain variable domains CDR-L1, CDR-L2, and CDR-L3 having the amino acid sequence of SEQ ID NO: 118.

[0257] In some embodiments, the anti-TfR antibodies of the present disclosure include 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.

[0258] In some aspects, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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.

[0259] In some embodiments, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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.

[0260] In some aspects, the anti-TfR antibodies of the present disclosure include: CDR-H1 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 79; CDR-H2 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 114; and / or CDR-H3 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 115. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure include: CDR-L1 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 82; CDR-L2 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 83; and / or (for example, and) CDR-L3 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 116.

[0261] In some embodiments, the anti-TfR antibody of the present disclosure comprises VH, which contains the amino acid sequence of SEQ ID NO: 117. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises VL, which contains the amino acid sequence of SEQ ID NO: 118.

[0262] In some embodiments, the anti-TfR antibody of the present disclosure comprises VH containing only 25 amino acid variations (e.g., only 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 VH as represented by SEQ ID NO: 117. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises VL containing only 25 amino acid variations (e.g., only 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 VL as represented by SEQ ID NO: 118.

[0263] In some embodiments, the anti-TfR antibody of the present disclosure comprises a VH having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VH as represented by SEQ ID NO: 117. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises a VL having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL as represented by SEQ ID NO: 118.

[0264] In some embodiments, the anti-TfR antibody of the present disclosure comprises heavy chain variable domains CDR-H1, CDR-H2, and CDR-H3 having the amino acid sequence of SEQ ID NO: 124. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises light chain variable domains CDR-L1, CDR-L2, and CDR-L3 having the amino acid sequence of SEQ ID NO: 125.

[0265] In some embodiments, the anti-TfR antibodies of the present disclosure include 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.

[0266] In some aspects, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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.

[0267] In some embodiments, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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.

[0268] In some aspects, the anti-TfR antibodies of the present disclosure include: CDR-H1 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 119; CDR-H2 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 120; and / or CDR-H3 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 121. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure include: CDR-L1 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 122; CDR-L2 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 45; and / or (for example, and) CDR-L3 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 123.

[0269] In some embodiments, the anti-TfR antibody of the present disclosure comprises VH, which contains the amino acid sequence of SEQ ID NO: 124. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises VL, which contains the amino acid sequence of SEQ ID NO: 125.

[0270] In some embodiments, the anti-TfR antibody of the present disclosure comprises a VH containing only 25 amino acid variations (e.g., only 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 VH as represented by SEQ ID NO: 124. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises a VL containing only 25 amino acid variations (e.g., only 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 VL as represented by SEQ ID NO: 125.

[0271] In some embodiments, the anti-TfR antibody of the present disclosure comprises a VH having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VH as represented by SEQ ID NO: 124. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises a VL having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL as represented by SEQ ID NO: 125.

[0272] In some embodiments, the anti-TfR antibody of the present disclosure comprises heavy chain variable domains CDR-H1, CDR-H2, and CDR-H3 having the amino acid sequence of SEQ ID NO: 132. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises light chain variable domains CDR-L1, CDR-L2, and CDR-L3 having the amino acid sequence of SEQ ID NO: 133.

[0273] In some embodiments, the anti-TfR antibodies of the present disclosure include 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.

[0274] In some aspects, the anti-TfR antibodies of the Disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the Disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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.

[0275] In some embodiments, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together are at least 75% (for example, 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together are at least 75% (for example, 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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.

[0276] In some aspects, the anti-TfR antibodies of the present disclosure include: CDR-H1 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 126; CDR-H2 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 127; and / or CDR-H3 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 128. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure include: CDR-L1 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 129; CDR-L2 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 130; and / or (for example, and) CDR-L3 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 131.

[0277] In some embodiments, the anti-TfR antibody of the present disclosure comprises VH, which contains the amino acid sequence of SEQ ID NO: 132. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises VL, which contains the amino acid sequence of SEQ ID NO: 133.

[0278] In some embodiments, the anti-TfR antibody of the present disclosure comprises VH containing only 25 amino acid variations (e.g., only 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 VH as represented by SEQ ID NO: 132. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises VL containing only 25 amino acid variations (e.g., only 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 VL as represented by SEQ ID NO: 133.

[0279] In some embodiments, the anti-TfR antibody of the present disclosure comprises a VH having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VH as represented by SEQ ID NO: 132. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises a VL having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL as represented by SEQ ID NO: 133.

[0280] In some embodiments, the anti-TfR antibody of the present disclosure comprises heavy chain variable domains CDR-H1, CDR-H2, and CDR-H3 having the amino acid sequence of SEQ ID NO: 136. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises light chain variable domains CDR-L1, CDR-L2, and CDR-L3 having the amino acid sequence of SEQ ID NO: 137.

[0281] In some embodiments, the anti-TfR antibodies of the present disclosure include 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.

[0282] In some aspects, the anti-TfR antibodies of the Disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the Disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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.

[0283] In some embodiments, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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.

[0284] In some aspects, the anti-TfR antibodies of the present disclosure include: CDR-H1 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 79; CDR-H2 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 2; and / or CDR-H3 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 134. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure include: CDR-L1 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 75; CDR-L2 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 45; and / or (for example, and) CDR-L3 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 135.

[0285] In some embodiments, the anti-TfR antibody of the present disclosure comprises VH, which comprises the amino acid sequence of SEQ ID NO: 136. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises VL, which comprises the amino acid sequence of SEQ ID NO: 137.

[0286] In some embodiments, the anti-TfR antibody of the present disclosure comprises a VH containing only 25 amino acid variations (e.g., only 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 VH as represented by SEQ ID NO: 136. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises a VL containing only 25 amino acid variations (e.g., only 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 VL as represented by SEQ ID NO: 137.

[0287] In some embodiments, the anti-TfR antibody of the present disclosure comprises a VH having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VH as represented by SEQ ID NO: 136. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises a VL having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL as represented by SEQ ID NO: 137.

[0288] In some embodiments, the anti-TfR antibody of the present disclosure comprises heavy chain variable domains CDR-H1, CDR-H2, and CDR-H3 having the amino acid sequence of SEQ ID NO: 143. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises light chain variable domains CDR-L1, CDR-L2, and CDR-L3 having the amino acid sequence of SEQ ID NO: 144.

[0289] In some embodiments, the anti-TfR antibodies of the present disclosure include 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.

[0290] In some aspects, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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.

[0291] In some embodiments, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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.

[0292] In some aspects, the anti-TfR antibodies of the present disclosure include: CDR-H1 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 138; CDR-H2 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 139; and / or CDR-H3 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 140. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure include: CDR-L1 having only three amino acid variations (for example, only three, two, or one amino acid variations) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 141; CDR-L2 having only three amino acid variations (for example, only three, two, or one amino acid variations) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 29; and / or (for example, and) CDR-L3 having only three amino acid variations (for example, only three, two, or one amino acid variations) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 142.

[0293] In some embodiments, the anti-TfR antibody of the present disclosure comprises VH, which contains the amino acid sequence of SEQ ID NO: 143. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises VL, which contains the amino acid sequence of SEQ ID NO: 144.

[0294] In some embodiments, the anti-TfR antibody of the present disclosure comprises a VH containing only 25 amino acid variations (e.g., only 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 VH as represented by SEQ ID NO: 143. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises a VL containing only 25 amino acid variations (e.g., only 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 VL as represented by SEQ ID NO: 144.

[0295] In some embodiments, the anti-TfR antibody of the present disclosure comprises a VH having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VH as represented by SEQ ID NO: 143. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises a VL having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL as represented by SEQ ID NO: 144.

[0296] The CDR of an antibody may have different amino acid sequences when different definition systems are used (e.g., IMGT definition, Kabat definition, or Chothia definition). A definition system annotates each amino acid in a given antibody sequence (e.g., a VH or VL sequence) with a number, and the numbers corresponding to the heavy and light chain CDRs are provided in Table 3. The CDRs listed in Table 2 are defined according to the IMGT definition. CDR sequences of example anti-TfR antibodies following various definition systems are provided in Table 4. Those skilled in the art can derive the CDR sequences of the anti-TfR antibodies provided in Table 2 using various numbering systems. Table 3. CDR definition [Table 3] 1 IMGT®, the international ImMunoGeneTics information system®, imgt.org, Lefranc, M.-P. et al., Nucleic Acids Res., 27:209-212 (1999) 2 Kabat et al. (1991) Sequences of Proteins of Immunological Interest, Fifth Edition, US Department of Health and Human Services, NIH Publication No. 91-3242 3 Chothia et al., J. Mol. Biol. 196:901-917 (1987)) Table 4. CDR sequences of examples of anti-TfR1 antibodies according to various definition systems. [Table 4-1] [Table 4-2]

[0297] In some embodiments, the anti-TfR antibodies of the present disclosure include 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: 263, or SEQ ID NO: 265, 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.

[0298] In some aspects, the anti-TfR antibodies of the Disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together contain only 5 amino acid variations (for example, only 5, 4, 3, 2, or 1 amino acid variation) compared to 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: 263, or SEQ ID NO: 265, and CDR-H3 having the amino acid sequence of SEQ ID NO: 147. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the Disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together contain only 5 amino acid variations (for example, only 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.

[0299] In some embodiments, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together are at least 75% (for example, 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to 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: 263, or SEQ ID NO: 265, and CDR-H3 having the amino acid sequence of SEQ ID NO: 147. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together are at least 75% (for example, 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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.

[0300] In some embodiments, the anti-TfR antibodies of the present disclosure include: CDR-H1 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 145; CDR-H2 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 146, SEQ ID NO: 263, or SEQ ID NO: 265; and / or CDR-H3 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 147 (e.g., and). Alternatively or in addition (for example, in addition), the anti-TfR antibodies of this disclosure include: CDR-L1 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 148; CDR-L2 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 149; and / or (for example, and) CDR-L3 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 6.

[0301] In some embodiments, the anti-TfR antibodies of the present disclosure include 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: 270, or SEQ ID NO: 271, 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.

[0302] In some aspects, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) compared to 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: 270, or SEQ ID NO: 271, and CDR-H3 having the amino acid sequence of SEQ ID NO: 152. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together contain only 5 amino acid variations (e.g., only 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.

[0303] In some embodiments, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together are at least 75% (for example, 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to 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: 270, or SEQ ID NO: 271, and CDR-H3 having the amino acid sequence of SEQ ID NO: 152. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together are at least 75% (for example, 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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.

[0304] In some aspects, the anti-TfR antibodies of the present disclosure include: CDR-H1 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 150; CDR-H2 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 151, SEQ ID NO: 270, or SEQ ID NO: 271; and / or (e.g., and) CDR-H3 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 152. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure include: CDR-L1 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 153; CDR-L2 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 5; and / or (for example, and) CDR-L3 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 154.

[0305] In some embodiments, the anti-TfR antibodies of the present disclosure include 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.

[0306] In some aspects, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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.

[0307] In some embodiments, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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.

[0308] In some aspects, the anti-TfR antibodies of the present disclosure include: CDR-H1 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 155; CDR-H2 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 156; and / or CDR-H3 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 157. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure include: CDR-L1 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 158; CDR-L2 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 159; and / or (for example, and) CDR-L3 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 14.

[0309] In some embodiments, the anti-TfR antibodies of the present disclosure include 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.

[0310] In some aspects, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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.

[0311] In some embodiments, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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.

[0312] In some aspects, the anti-TfR antibodies of the present disclosure include: CDR-H1 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 160; CDR-H2 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 161; and / or CDR-H3 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 162. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure include: CDR-L1 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 163; CDR-L2 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 13; and / or (for example, and) CDR-L3 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 164.

[0313] In some embodiments, the anti-TfR antibodies of the present disclosure include CDR-H1 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 165, SEQ ID NO: 267, or SEQ ID NO: 269; 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.

[0314] In some embodiments, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 165, SEQ ID NO: 267, or SEQ ID NO: 269, 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together contain only 5 amino acid variations (e.g., only 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.

[0315] In some embodiments, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together are at least 75% (for example, 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to CDR-H1 having the amino acid sequence of SEQ ID NO: 165, SEQ ID NO: 267, or SEQ ID NO: 269, 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. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together are at least 75% (for example, 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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.

[0316] In some embodiments, the anti-TfR antibodies of the present disclosure include: CDR-H1 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 165, SEQ ID NO: 267, or SEQ ID NO: 269; CDR-H2 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 166; and / or CDR-H3 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 167. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure include: CDR-L1 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 168; CDR-L2 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 169; and / or (for example, and) CDR-L3 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 22.

[0317] In some embodiments, the anti-TfR antibodies of the present disclosure include 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.

[0318] In some aspects, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together contain only 5 amino acid variations (e.g., only 5, 4, 3, 2, or 1 amino acid variation) 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.

[0319] In some embodiments, the anti-TfR antibodies of the present disclosure comprise CDR-H1, CDR-H2, and CDR-H3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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. Alternatively or in addition (e.g., in addition), the anti-TfR antibodies of the present disclosure comprise CDR-L1, CDR-L2, and CDR-L3, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical 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.

[0320] In some aspects, the anti-TfR antibodies of the present disclosure include: CDR-H1 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H1 having the amino acid sequence of SEQ ID NO: 170; CDR-H2 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H2 having the amino acid sequence of SEQ ID NO: 171; and / or CDR-H3 having only three amino acid variations (e.g., only three, two, or one amino acid variation) compared to CDR-H3 having the amino acid sequence of SEQ ID NO: 172. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of the present disclosure include: CDR-L1 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L1 having the amino acid sequence of SEQ ID NO: 173; CDR-L2 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L2 having the amino acid sequence of SEQ ID NO: 21; and / or (for example, and) CDR-L3 having only 3 amino acid variations (for example, only 3, 2, or 1 amino acid variations) compared to CDR-L3 having the amino acid sequence of SEQ ID NO: 174.

[0321] In some embodiments, the anti-TfR antibodies of the Disclosure are humanized antibodies (e.g., humanized variants containing one or more CDRs from Table 2 or Table 4). In some embodiments, the anti-TfR antibodies of the Disclosure include the same CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2, and CDR-L3 as shown in Table 2 or Table 4, and include a humanized heavy chain variable region and / or (e.g., and) a humanized light chain variable region.

[0322] A humanized antibody is a human immunoglobulin (recipient antibody) in which residues from the recipient's complementarity-determining region (CDR) are replaced with residues from the CDR of a non-human species (donor antibody), such as mouse, rat, or rabbit, having the desired specificity, affinity, and volume. In some embodiments, Fv framework region (ER) residues of the human immunoglobulin are replaced with corresponding non-human residues. Furthermore, the humanized antibody may also include residues that are not found on the recipient antibody or on the transferred CDR or framework sequence, but are included to further improve and optimize antibody performance. Generally, a humanized antibody will contain substantially all of at least one, typically two, variable domains, where all or substantially all of the CDR region corresponds to that of a non-human immunoglobulin, and all or substantially all of the FR region corresponds to that of the human immunoglobulin consensus sequence. Optimally, the humanized antibody will also contain at least some portion (Fc) of the immunoglobulin constant region or domain, typically that of the human immunoglobulin. Antibodies may have modified Fc regions as described in WO99 / 58572. Other forms of humanized antibodies have one or more CDRs (one, two, three, four, five, or six) that are modified from the original antibody. These are also referred to as one or more CDRs derived from one or more CDRs from the original antibody. Affinity maturation may also be involved in humanized antibodies.

[0323] Humanized antibodies and methods for producing them are known, for example, 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. Patents 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 As described in 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 these contents are incorporated herein by reference. Human framework regions that can be used 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., J Biol.Chem.271:22611-22618(1996). All of these contents are incorporated herein by reference. In some embodiments, humanization is achieved by grafting CDRs (as shown, for example, in Table 2 or Table 4) onto the IGKV1-NL1*01 and IGHV1-3*01 human variable domains.

[0324] In some embodiments, the humanized VH framework or VL framework is a consensus human framework. In some embodiments, the consensus humanized framework may represent the most commonly occurring amino acid residues in a selection of human immunoglobulin VL or VH framework sequences.

[0325] In some embodiments, the consensus human VH framework region suitable for use in heavy chain CDRs of the humanized anti-TfR antibodies described herein (subgroup III consensus) is as follows:

[0326] a) VH FR1:EVQLVESGGGLVQPGGSLRLSCAAS(Sequence ID 272);

[0327] b) VH FR2:WVRQAPGKGLEWV(Sequence ID 273);

[0328] c) VH FR3:RFTISRDNSKNTLYLQMNSLRAEDTAVYYC(sequence number 274); and

[0329] d) VH FR4:WGQGTLVTVSS (Sequence ID 275) It includes.

[0330] In some embodiments, the consensus human VH framework region suitable for use in heavy chain CDRs of the humanized anti-TfR antibodies described herein (subgroup I consensus) is as follows:

[0331] a) VH FR1:QVQLVQSGAEVKKPGASVKVSCKAS(Sequence ID 276);

[0332] b) VH FR2:WVRQAPGQGLEWM(Sequence ID 277);

[0333] c) VH FR3:RVTITADTSTSTAYMELSSLRSEDTAVYYC(Sequence ID 278); and

[0334] d) VH FR4:WGQGTLVTVSS (Sequence ID 275) It includes.

[0335] In some embodiments, the consensus human VH framework region suitable for use in heavy chain CDRs of the humanized anti-TfR antibodies described herein (subgroup II consensus) is as follows:

[0336] a) VH FR1:QVQLQESGPGLVKPSQTLSLTCTVS(Sequence ID 280);

[0337] b) VH FR2:WIRQPPGKGLEWI(Sequence ID 281);

[0338] c) VH FR3:RVTISVDTSKNQFSLKLSSVTAADTAVYYC(sequence code 282); and

[0339] d) VH FR4:WGQGTLVTVSS (Sequence ID 275) It includes.

[0340] In some embodiments, the consensus human VL framework region suitable for use in light chain CDRs of the humanized anti-TfR antibodies described herein (subgroup I consensus) is as follows:

[0341] a) VL FR1:DIQMTQSPSSLSASVGDRVTITC(Sequence ID 284);

[0342] b) VL FR2:WYQQKPGKAPKLLIY(Sequence ID 285);

[0343] c) VL FR3:GVPSRFSGSGSGTDFTLTISSLQPEDFATYYC(Sequence ID 286); and

[0344] d) VL FR4:FGQGTKVEIK (Sequence ID 279) It includes.

[0345] In some embodiments, the consensus human VL framework region suitable for use in light chain CDRs of the humanized anti-TfR antibodies described herein (subgroup II consensus) is as follows:

[0346] a) VL FR1:DIVMTQSPLSLPVTPGEPASISC(Sequence ID 288);

[0347] b) VL FR2:WYLQKPGQSPQLLIY(Sequence ID 289);

[0348] c) VL FR3:GVPDRFSGSGSGTDFTLKISRVEAEDVGVYYC(Sequence ID 290); and

[0349] d) VL FR4:FGQGTKVEIK (Sequence ID 279) It includes.

[0350] In some embodiments, the consensus human VL framework region suitable for use in light chain CDRs of the humanized anti-TfR antibodies described herein (subgroup III consensus) is as follows:

[0351] a) VL FR1:DIVMTQSPDSLAVSLGERATINC(Sequence ID 283);

[0352] b) VL FR2:WYQQKPGQPPKLLIY(Sequence ID 287);

[0353] c) VL FR3:GVPDRFSGSGSGTDFTLTISSLQAEDFAVYYC(Sequence ID 291); and

[0354] d) VL FR4:FGQGTKVEIK (Sequence ID 279) It includes.

[0355] In some embodiments, the consensus human VL framework region suitable for use in light chain CDRs of the humanized anti-TfR antibodies described herein (subgroup IV consensus) is as follows:

[0356] a) VL FR1:DIVMTQSPDSLAVSLGERATINC(Sequence ID 283);

[0357] b) VL FR2:WYQQKPGQPPKLLIY(Sequence ID 287);

[0358] c)VL FR3:GVPDRFSGSGSGTDFTLTISSLQAEDFAVYYC(Sequence ID 291); and

[0359] d) VL FR4:FGQGTKVEIK (Sequence ID 279) It includes.

[0360] In some embodiments, the humanized anti-TfR antibodies of this disclosure comprise humanized VH framework regions, which together contain as few as 25 amino acid variations (for example, as few as 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 any one of the consensus human VH framework region subgroups described herein. Alternatively or in addition (for example, in addition), the humanized anti-TfR antibodies of this disclosure include humanized VL framework regions, which together contain as few as 25 amino acid variations (for example, as few as 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 any one of the consensus human VL framework region subgroups described herein.

[0361] In some embodiments, the humanized anti-TfR antibodies of this disclosure include humanized VH framework regions, which together are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to any one of the consensus human VH framework region subgroups described herein. Alternatively or in addition (e.g., in addition), the humanized anti-TfR antibodies of this disclosure include humanized VL framework regions, which are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to any one of the consensus human VL framework region subgroups described herein.

[0362] In some embodiments, the anti-TfR antibody of the present disclosure is a humanized variant comprising one or more amino acid variations (e.g., of the VH framework region) compared to any one of the VHs listed in Table 2 or Table 4 and / or (e.g., and) one or more amino acid variations (e.g., of the VL framework region) compared to any one of the VLs listed in Table 2 or Table 4.

[0363] In some embodiments, the anti-TfR antibody of the Disclosure is a humanized antibody comprising a VH containing only 25 amino acid variations (e.g., only 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 any VH of any of the anti-TfR antibodies listed in Table 2. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the Disclosure is a humanized antibody comprising a VL containing only 25 amino acid variations (e.g., only 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 any VL of any of the anti-TfR antibodies listed in Table 2.

[0364] In some embodiments, the anti-TfR antibody of the Disclosure is a humanized antibody comprising a VH having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VH as represented by any one of SEQ ID NOs: 7, 15, and 23. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the Disclosure is a humanized antibody comprising a VL having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL as represented by any one of SEQ ID NOs: 8, 16, and 24.

[0365] In some embodiments, the anti-TfR antibody of the present disclosure is a humanized antibody and includes a VH having only 25 amino acid variations (for example, only 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 VH as represented by any one of SEQ ID NOs: 7, 15, and 23. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure is a humanized antibody and includes a VL containing only 25 amino acid variations (for example, only 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 a VL as represented by any one of SEQ ID NOs.

[0366] In some embodiments, the anti-TfR antibody of the Disclosure is a humanized antibody comprising a VH having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VH as represented by any one of SEQ ID NOs: 7, 15, and 23. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the Disclosure is a humanized antibody comprising a VL having an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL as represented by any one of SEQ ID NOs: 8, 16, and 24.

[0367] In some embodiments, the anti-TfR antibody of the present disclosure is a humanized antibody and comprises a 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, compared to VH as represented by any one of SEQ ID NOs: 7, 15, and 23. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure is a humanized antibody and comprises a VL having one or more (for example, 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, compared to a VL as represented by any one of SEQ ID NOs: 8, 16, and 24.

[0368] In some embodiments, the anti-TfR antibody of the present disclosure comprises humanized VH, and includes 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: 262, or SEQ ID NO: 80, and CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 3, and contains only 25 amino acid variations in the framework region (for example, only 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 VH as represented by SEQ ID NO: 7. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present 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 only 25 amino acid variations in the framework region (for example, only 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 as represented by SEQ ID NO: 8.

[0369] In some embodiments, the anti-TfR antibody of the present disclosure comprises humanized VH including 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: 262, or SEQ ID NO: 80, and CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 3, which is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to VH as represented by SEQ ID NO: 7 in the framework region. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises a humanized VL having the amino acid sequence of SEQ ID NO: 4 (according to the IMGT definition system), CDR-L2 having the amino acid sequence of SEQ ID NO: 5 (according to the IMGT definition system), and CDR-L3 having the amino acid sequence of SEQ ID NO: 6 (according to the IMGT definition system), which is at least 75% (for example, 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL as represented by SEQ ID NO: 8 in the framework region.

[0370] In some embodiments, the anti-TfR antibody of the present disclosure comprises humanized VH, and includes 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: 263, or SEQ ID NO: 265, and CDR-H3 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 147, and contains only 25 amino acid variations in the framework region (for example, only 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 VH as represented by SEQ ID NO: 7. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present 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 containing only 25 amino acid variations in the framework region (for example, only 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 as represented by SEQ ID NO: 8.

[0371] In some embodiments, the anti-TfR antibody of the present disclosure comprises humanized VH including 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: 263, or SEQ ID NO: 265, and CDR-H3 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 147, which is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to VH as represented by SEQ ID NO: 7 in the framework region. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises a humanized VL having the amino acid sequence of SEQ ID NO: 148 (according to the Kabat definition system), CDR-L2 having the amino acid sequence of SEQ ID NO: 149 (according to the Kabat definition system), and CDR-L3 having the amino acid sequence of SEQ ID NO: 6 (according to the Kabat definition system), which is at least 75% (for example, 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL as represented by SEQ ID NO: 8 in the framework region.

[0372] In some embodiments, the anti-TfR antibody of the present disclosure comprises humanized VH, and includes 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: 270, or SEQ ID NO: 271, and CDR-H3 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 152, and contains only 25 amino acid variations in the framework region (for example, only 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 VH as represented by SEQ ID NO: 7. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises a humanized VL and includes 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 contains only 25 amino acid variations in the framework region (for example, only 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 as represented by SEQ ID NO: 8.

[0373] In some embodiments, the anti-TfR antibody of the present disclosure comprises humanized VH including 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: 270, or SEQ ID NO: 271, and CDR-H3 (according to the Chothia definition system) having the amino acid sequence of SEQ ID NO: 152, which is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to VH as represented by SEQ ID NO: 7 in the framework region. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises a humanized VL having the amino acid sequence of SEQ ID NO: 153 (according to the Chothia definition system), CDR-L2 having the amino acid sequence of SEQ ID NO: 5 (according to the Chothia definition system), and CDR-L3 having the amino acid sequence of SEQ ID NO: 154 (according to the Chothia definition system), which is at least 75% (for example, 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL as represented by SEQ ID NO: 8 in the framework region.

[0374] In some embodiments, the anti-TfR antibody of the present disclosure comprises humanized VH, and includes 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 contains only 25 amino acid variations in the framework region (for example, only 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 VH as represented by SEQ ID NO: 15. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present 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 containing only 25 amino acid variations in the framework region (for example, only 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 as represented by SEQ ID NO: 16.

[0375] In some embodiments, the anti-TfR antibody of the present disclosure comprises humanized VH including 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, which are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to VH as represented by SEQ ID NO: 15 in the framework region. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises a humanized VL having the amino acid sequence of SEQ ID NO: 12 (according to the IMGT definition system), CDR-L2 having the amino acid sequence of SEQ ID NO: 13 (according to the IMGT definition system), and CDR-L3 having the amino acid sequence of SEQ ID NO: 14 (according to the IMGT definition system), which is at least 75% (for example, 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL as represented by SEQ ID NO: 16 in the framework region.

[0376] In some embodiments, the anti-TfR antibody of the present disclosure comprises humanized VH, and includes 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 contains only 25 amino acid variations in the framework region (for example, only 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 VH as represented by SEQ ID NO: 15. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises a humanized VL and includes 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 contains only 25 amino acid variations in the framework region (for example, only 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 as represented by SEQ ID NO: 16.

[0377] In some embodiments, the anti-TfR antibody of the present disclosure comprises humanized VH including 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, which are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to VH as represented by SEQ ID NO: 15 in the framework region. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises a humanized VL having the amino acid sequence of SEQ ID NO: 158 (according to the Kabat definition system), CDR-L2 having the amino acid sequence of SEQ ID NO: 159 (according to the Kabat definition system), and CDR-L3 having the amino acid sequence of SEQ ID NO: 14 (according to the Kabat definition system), which is at least 75% (for example, 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL as represented by SEQ ID NO: 16 in the framework region.

[0378] In some embodiments, the anti-TfR antibody of the present disclosure comprises humanized VH, and includes 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 contains only 25 amino acid variations in the framework region (for example, only 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 VH as represented by SEQ ID NO: 15. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises a humanized VL and includes 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 contains only 25 amino acid variations in the framework region (for example, only 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 as represented by SEQ ID NO: 16.

[0379] In some embodiments, the anti-TfR antibody of the present disclosure comprises humanized VH including 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, which are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to VH as represented by SEQ ID NO: 15 in the framework region. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises a humanized VL having the amino acid sequence of SEQ ID NO: 163 (according to the Chothia definition system), CDR-L2 having the amino acid sequence of SEQ ID NO: 13 (according to the Chothia definition system), and CDR-L3 having the amino acid sequence of SEQ ID NO: 164 (according to the Chothia definition system), which is at least 75% (for example, 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL as represented by SEQ ID NO: 16 in the framework region.

[0380] In some embodiments, the anti-TfR antibody of the present disclosure comprises humanized VH and includes CDR-H1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 17, SEQ ID NO: 266, or SEQ ID NO: 268, CDR-H2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 18, and CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 19, and contains only 25 amino acid variations in the framework region (for example, only 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 VH as represented by SEQ ID NO: 23. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises a humanized VL and includes 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 only 25 amino acid variations in the framework region (for example, only 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 as represented by SEQ ID NO: 24.

[0381] In some embodiments, the anti-TfR antibody of the present disclosure comprises humanized VH including CDR-H1 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 17, SEQ ID NO: 266, or SEQ ID NO: 268, CDR-H2 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 18, and CDR-H3 (according to the IMGT definition system) having the amino acid sequence of SEQ ID NO: 19, which are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to VH as represented by SEQ ID NO: 23 in the framework region. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises a humanized VL having the amino acid sequence of SEQ ID NO: 20 (according to the IMGT definition system), CDR-L2 having the amino acid sequence of SEQ ID NO: 21 (according to the IMGT definition system), and CDR-L3 having the amino acid sequence of SEQ ID NO: 22 (according to the IMGT definition system), which is at least 75% (for example, 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL as represented by SEQ ID NO: 24 in the framework region.

[0382] In some embodiments, the anti-TfR antibody of the present disclosure comprises humanized VH and includes CDR-H1 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 165, SEQ ID NO: 267, or SEQ ID NO: 269, CDR-H2 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 166, and CDR-H3 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 167, and contains only 25 amino acid variations in the framework region (for example, only 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 VH as represented by SEQ ID NO: 23. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises a humanized VL and includes 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 contains only 25 amino acid variations in the framework region (for example, only 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 as represented by SEQ ID NO: 24.

[0383] In some embodiments, the anti-TfR antibody of the present disclosure comprises humanized VH including CDR-H1 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 165, SEQ ID NO: 267, or SEQ ID NO: 269, CDR-H2 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 166, and CDR-H3 (according to the Kabat definition system) having the amino acid sequence of SEQ ID NO: 167, which are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to VH as represented by SEQ ID NO: 23 in the framework region. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises a humanized VL having the amino acid sequence of SEQ ID NO: 168 (according to the Kabat definition system), CDR-L2 having the amino acid sequence of SEQ ID NO: 169 (according to the Kabat definition system), and CDR-L3 having the amino acid sequence of SEQ ID NO: 22 (according to the Kabat definition system), which is at least 75% (for example, 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL as represented by SEQ ID NO: 24 in the framework region.

[0384] In some embodiments, the anti-TfR antibody of the present disclosure comprises humanized VH, and includes 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 contains only 25 amino acid variations in the framework region (for example, only 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 VH as represented by SEQ ID NO: 23. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present 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 containing only 25 amino acid variations in the framework region (for example, only 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 as represented by SEQ ID NO: 24.

[0385] In some embodiments, the anti-TfR antibody of the present disclosure comprises humanized VH including 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, which are at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to VH as represented by SEQ ID NO: 23 in the framework region. Alternatively or in addition (for example, in addition), the anti-TfR antibody of the present disclosure comprises a humanized VL having the amino acid sequence of SEQ ID NO: 173 (according to the Chothia definition system), CDR-L2 having the amino acid sequence of SEQ ID NO: 21 (according to the Chothia definition system), and CDR-L3 having the amino acid sequence of SEQ ID NO: 174 (according to the Chothia definition system), which is at least 75% (for example, 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to the VL as represented by SEQ ID NO: 24 in the framework region.

[0386] In some embodiments, the anti-TfR antibodies of this disclosure are chimeric antibodies, which may encompass heavy chain constant regions and light chain constant regions from a human antibody. A chimeric antibody refers to an antibody having a variable region or a portion of a variable region from a first species and a constant region from a second species. Typically, in these chimeric antibodies, both the light and heavy chain variable regions mimic the variable region of an antibody derived from one mammalian species (e.g., non-human mammals, e.g., mouse, rabbit, and rat), while the constant portion is homologous to the sequence of an antibody derived from another mammal, e.g., human. In some embodiments, amino acid modifications may be made to the variable region and / or (e.g., and) the constant region.

[0387] In some embodiments, the anti-TfR antibodies described herein are chimeric antibodies, which may encompass the heavy chain constant region and light chain constant region from a human antibody. A chimeric antibody refers to an antibody having a variable region or a portion of a variable region from a first species and a constant region from a second species. Typically, in these chimeric antibodies, both the light and heavy chain variable regions mimic the variable region of an antibody derived from one mammalian species (e.g., non-human mammals, such as mice, rabbits, and rats), while the constant portion is homologous to the sequence of an antibody derived from another mammal, such as humans. In some embodiments, amino acid modifications may be made to the variable region and / or (e.g., and) the constant region.

[0388] In some embodiments, the heavy chain of any of the anti-TfR antibodies described herein may include a heavy chain constant region (CH) or a portion thereof (e.g., CH1, CH2, CH3, or a combination thereof). The heavy chain constant region may be of any preferred origin, e.g., human, mouse, rat, or rabbit. In one specific example, the heavy chain constant region is from human IgG (gamma heavy chain), e.g., IgG1, IgG2, or IgG4. An example of the human IgG1 constant region is given below: ASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK(Sequence ID 175)

[0389] In some embodiments, the heavy chain of any of the anti-TfR antibodies described herein comprises a mutant human IgG1 constant region. For example, the introduction of an LALA mutation on the CH2 domain of human IgG1 (a mutant derived from mAb b12 mutated to replace the lower hinge residues Leu234 Leu235 with Ala234 and Ala235) is known to reduce Fcg receptor binding (Bruhns, P., et al. (2009) and Xu, D. et al. (2000)). Mutant human IgG1 constant regions are provided below (mutations are in bold and underlined):

[0390] [ka] (Sequence ID 176)

[0391] In some embodiments, any light chain of any of the anti-TfR antibodies described herein may further comprise a light chain constant region (CL), which may be any CL known in the art. In some examples, the CL is a kappa light chain. In other examples, the CL is a lambda light chain. In some embodiments, the CL is a kappa light chain, and this sequence is provided below: RTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC (Sequence ID 177)

[0392] The heavy and light chain constant regions of other antibodies are well known in the art and are provided, for example, in the IMGT database (www.imgt.org) or at www.vbase2.org / vbstat.php, both of which are incorporated herein by reference.

[0393] In some embodiments, the anti-TfR antibodies described herein include a heavy chain comprising a VH or any of its variants listed in Table 2, and a heavy chain comprising a heavy chain constant region that is at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical to SEQ ID NO: 175 or SEQ ID NO: 176. In some embodiments, the anti-TfR antibodies described herein include a heavy chain comprising a VH or any of its variants listed in Table 2, and a heavy chain comprising a heavy chain constant region containing only 25 amino acid variations (for example, only 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 antibodies described herein comprise a heavy chain comprising one of the VH variants listed in Table 2 and a heavy chain constant region as represented by SEQ ID NO: 175. In some embodiments, the anti-TfR antibodies described herein comprise a heavy chain comprising one of the VH variants listed in Table 2 and a heavy chain constant region as represented by SEQ ID NO: 176.

[0394] In some embodiments, the anti-TfR antibodies described herein include a light chain comprising one of the VLs listed in Table 2 or any of their variants, and a light chain comprising a light chain constant region that is at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical to SEQ ID NO: 177. In some embodiments, the anti-TfR antibodies described herein include a light chain comprising one of the VLs listed in Table 2 or any of their variants, and a light chain comprising a light chain constant region containing only 25 amino acid variations (for example, only 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 antibodies described herein include a light chain comprising one of the VLs listed in Table 2 or any of their variants, and a light chain comprising a light chain constant region as represented by SEQ ID NO: 177.

[0395] Examples of IgG heavy and light chain amino acid sequences of the described anti-TfR antibodies are provided in Table 5 below. Table 5. Heavy and light chain sequences of examples of anti-TfR IgG. [Table 5-1] [Table 5-2] [Table 5-3] *VH / VL sequences are underlined.

[0396] In some embodiments, the anti-TfR antibodies of the present disclosure include a heavy chain containing only 25 amino acid variations (for example, only 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 as represented by SEQ ID NO: 178, SEQ ID NO: 180, SEQ ID NO: 182, SEQ ID NO: 300, SEQ ID NO: 301, SEQ ID NO: 302, or SEQ ID NO: 303. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of this disclosure include a light chain containing only 25 amino acid variations (for example, only 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 represented by SEQ ID NO: 179, SEQ ID NO: 181, or SEQ ID NO: 183. In some embodiments, the anti-TfR antibodies described herein include a heavy chain containing an amino acid sequence that is at least 75% (for example, 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to SEQ ID NO: 178, SEQ ID NO: 180, SEQ ID NO: 182, SEQ ID NO: 300, SEQ ID NO: 301, SEQ ID NO: 302, or SEQ ID NO: 303. Alternatively or in addition (for example, in addition), the anti-TfR antibodies described herein include a light chain containing an amino acid sequence that is at least 75% (for example, 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to SEQ ID NO: 179, SEQ ID NO: 181, or SEQ ID NO: 183. In some embodiments, the anti-TfR antibodies described herein include a heavy chain containing the amino acid sequence of SEQ ID NO: 178, SEQ ID NO: 180, SEQ ID NO: 182, SEQ ID NO: 300, SEQ ID NO: 301, SEQ ID NO: 302, or SEQ ID NO: 303. Alternatively or in addition (for example, in addition), the anti-TfR antibodies described herein include a light chain containing the amino acid sequence of SEQ ID NO: 179, SEQ ID NO: 181, or SEQ ID NO: 183.

[0397] In some embodiments, the anti-TfR antibody of the present disclosure comprises a heavy chain containing only 25 amino acid variations (e.g., only 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 as represented by SEQ ID NO: 178, SEQ ID NO: 300, or SEQ ID NO: 301. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises a light chain containing only 25 amino acid variations (e.g., 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 10, 11, 9, 8, 7, 6, only 5, 4, 3, 2, or 1 amino acid variation) compared to the light chain as represented by SEQ ID NO: 179. In some embodiments, the anti-TfR antibody described herein comprises a heavy chain containing an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to SEQ ID NO: 178, SEQ ID NO: 300, or SEQ ID NO: 301. Alternatively or in addition (e.g., in addition), the anti-TfR antibody described herein comprises a light chain containing an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to 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: 300, or SEQ ID NO: 301. Alternatively or in addition (e.g., in addition), the anti-TfR antibody described herein comprises a light chain containing the amino acid sequence of SEQ ID NO: 179.

[0398] In some embodiments, the anti-TfR antibody of the present disclosure comprises a heavy chain containing only 25 amino acid variations (e.g., only 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 as represented by SEQ ID NO: 180. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises a light chain containing only 25 amino acid variations (e.g., only 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 as represented by SEQ ID NO: 181. In some embodiments, the anti-TfR antibody described herein comprises a heavy chain containing an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to SEQ ID NO: 180. Alternatively or in addition (e.g., in addition), the anti-TfR antibody described herein comprises a light chain containing an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to 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 in addition (e.g., in addition), the anti-TfR antibody described herein comprises a light chain containing the amino acid sequence of SEQ ID NO: 181.

[0399] In some embodiments, the anti-TfR antibody of the present disclosure comprises a heavy chain containing only 25 amino acid variations (e.g., only 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 as represented by SEQ ID NO: 182, SEQ ID NO: 302, or SEQ ID NO: 303. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises a light chain containing only 25 amino acid variations (e.g., only 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 as represented by SEQ ID NO: 183. In some embodiments, the anti-TfR antibody described herein comprises a heavy chain containing an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to SEQ ID NO: 182, SEQ ID NO: 302, or SEQ ID NO: 303. Alternatively or in addition (e.g., in addition), the anti-TfR antibody described herein comprises a light chain containing an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to 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: 302, or SEQ ID NO: 303. Alternatively or in addition (e.g., in addition), the anti-TfR antibody described herein comprises a light chain containing the amino acid sequence of SEQ ID NO: 183.

[0400] In some embodiments, the anti-TfR antibody is a FAB fragment, F(ab') fragment, or F(ab')2 fragment of an intact antibody (full-length antibody). Antigen-binding fragments of intact antibodies (full-length antibodies) can be prepared by standard methods (e.g., recombinantly, or by digesting the heavy chain constant region of full-length IgG using an enzyme such as papain). For example, the F(ab')2 fragment may be produced by pepsin or papain digestion of the antibody molecule, and the Fab fragment may be produced by reducing the disulfide crosslinks of the F(ab')2 fragment. In some embodiments, the heavy chain constant region on the F(ab') fragment of the anti-TfR1 antibody described herein is as follows: Contains the amino acid sequence ASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHT (Sequence ID 184).

[0401] In some embodiments, the anti-TfR antibodies described herein include one of the VH variants listed in Table 2 and a heavy chain comprising a heavy chain constant region that is at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical to SEQ ID NO: 184. In some embodiments, the anti-TfR antibodies described herein include one of the VH variants listed in Table 2 and a heavy chain comprising a heavy chain constant region containing only 25 amino acid variations compared to SEQ ID NO: 184 (for example, only 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). In some embodiments, the anti-TfR antibodies described herein include one of the VH variants listed in Table 2 and a heavy chain comprising a heavy chain constant region as represented by SEQ ID NO: 184.

[0402] Examples of F(ab') amino acid sequences of anti-TfR antibodies described herein are provided in Table 6. Table 6. Examples of heavy chains and anti-TfR F(ab') Light chain arrangement [Table 6-1] [Table 6-2] [Table 6-3]

[0403] In some embodiments, the anti-TfR antibodies of the present disclosure include a heavy chain containing only 25 amino acid variations (for example, only 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 as represented by SEQ ID NO: 185, SEQ ID NO: 186, SEQ ID NO: 187, SEQ ID NO: 304, SEQ ID NO: 305, SEQ ID NO: 306, or SEQ ID NO: 307. Alternatively or in addition (for example, in addition), the anti-TfR antibodies of this disclosure include a light chain containing only 25 amino acid variations (for example, only 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 represented by SEQ ID NO: 179, SEQ ID NO: 181, or SEQ ID NO: 183. In some embodiments, the anti-TfR antibodies described herein include a heavy chain containing an amino acid sequence that is at least 75% (for example, 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to SEQ ID NO: 185, SEQ ID NO: 186, SEQ ID NO: 187, SEQ ID NO: 304, SEQ ID NO: 305, SEQ ID NO: 306, or SEQ ID NO: 307. Alternatively or in addition (for example, in addition), the anti-TfR antibodies described herein include a light chain containing an amino acid sequence that is at least 75% (for example, 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to SEQ ID NO: 179, SEQ ID NO: 181, or SEQ ID NO: 183. In some embodiments, the anti-TfR antibodies described herein include a heavy chain containing the amino acid sequence of SEQ ID NO: 185, SEQ ID NO: 186, SEQ ID NO: 187, SEQ ID NO: 304, SEQ ID NO: 305, SEQ ID NO: 306, or SEQ ID NO: 307. Alternatively or in addition (for example, in addition), the anti-TfR antibodies described herein include a light chain containing the amino acid sequence of SEQ ID NO: 179, SEQ ID NO: 181, or SEQ ID NO: 183.

[0404] In some embodiments, the anti-TfR antibody of the present disclosure comprises a heavy chain containing only 25 amino acid variations (e.g., only 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 as represented by SEQ ID NO: 185, SEQ ID NO: 304, or SEQ ID NO: 305. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises a light chain containing only 25 amino acid variations (e.g., only 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 as represented by SEQ ID NO: 179. In some embodiments, the anti-TfR antibody described herein comprises a heavy chain containing an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to SEQ ID NO: 185, SEQ ID NO: 304, or SEQ ID NO: 305. Alternatively or in addition (e.g., in addition), the anti-TfR antibody described herein comprises a light chain containing an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to 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: 304, or SEQ ID NO: 305. Alternatively or in addition (e.g., in addition), the anti-TfR antibody described herein comprises a light chain containing the amino acid sequence of SEQ ID NO: 179.

[0405] In some embodiments, the anti-TfR antibody of the present disclosure comprises a heavy chain containing only 25 amino acid variations (e.g., only 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 as represented by SEQ ID NO: 186. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises a light chain containing only 25 amino acid variations (e.g., 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 10, 11, 9, 8, 7, 6, only 5, 4, 3, 2, or 1 amino acid variation) compared to the light chain as represented by SEQ ID NO: 181. In some embodiments, the anti-TfR antibody described herein comprises a heavy chain containing an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to SEQ ID NO: 186. Alternatively or in addition (e.g., in addition), the anti-TfR antibody described herein comprises a light chain containing an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to 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 in addition (e.g., in addition), the anti-TfR antibody described herein comprises a light chain containing the amino acid sequence of SEQ ID NO: 181.

[0406] In some embodiments, the anti-TfR antibody of the present disclosure comprises a heavy chain containing only 25 amino acid variations (e.g., only 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 as represented by SEQ ID NO: 187, SEQ ID NO: 306, or SEQ ID NO: 307. Alternatively or in addition (e.g., in addition), the anti-TfR antibody of the present disclosure comprises a light chain containing only 25 amino acid variations (e.g., only 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 as represented by SEQ ID NO: 183. In some embodiments, the anti-TfR antibody described herein comprises a heavy chain containing an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to SEQ ID NO: 187, SEQ ID NO: 306, or SEQ ID NO: 307. Alternatively or in addition (e.g., in addition), the anti-TfR antibody described herein comprises a light chain containing an amino acid sequence that is at least 75% (e.g., 75%, 80%, 85%, 90%, 95%, 98%, or 99%) identical to 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: 306, or SEQ ID NO: 307. Alternatively or in addition (e.g., in addition), the anti-TfR antibody described herein comprises a light chain containing the amino acid sequence of SEQ ID NO: 183.

[0407] The anti-TfR receptor antibodies described herein may be in any antibody form, including, but not limited to, intact (i.e., 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 antibodies described herein are scFv. In some embodiments, the anti-TfR antibodies described herein are scFv-Fab (e.g., scFv fused to a portion of the constant region). In some embodiments, the anti-TfR receptor antibodies described herein are scFv fused to a constant region (e.g., the human IgG1 constant region, or a portion thereof, e.g., the Fc portion, as represented by SEQ ID NO: 175 or SEQ ID NO: 176) at either the N-terminus or the C-terminus.

[0408] In some embodiments, any one of the anti-TfR1 antibodies described herein may comprise a signal peptide (e.g., an N-terminal signal peptide) on the heavy chain and / or (e.g., and) light chain sequences. In some embodiments, the anti-TfR1 antibodies described herein comprise either one of the VH and VL sequences, either one of the IgG heavy chain and light chain sequences, or either one of the F(ab') heavy chain and light chain sequences described herein, and further comprise a signal peptide (e.g., an N-terminal signal peptide). In some embodiments, the signal peptide comprises the amino acid s...

Claims

1. A complex comprising an anti-transferrin receptor antibody covalently linked to a molecular payload configured to modulate the expression or activity of a muscle disease gene, Here, the anti-transferrin receptor antibody is as follows: (i) Heavy chain complementarity determination region 1 (CDR-H1) of SEQ ID NO: 155, heavy chain complementarity determination region 2 (CDR-H2) of SEQ ID NO: 156, heavy chain complementarity determination region 3 (CDR-H3) of SEQ ID NO: 157, light chain complementarity determination region 1 (CDR-L1) of SEQ ID NO: 158, light chain complementarity determination region 2 (CDR-L2) of SEQ ID NO: 159, and light chain complementarity determination region 3 (CDR-L3) of SEQ ID NO: 14; (ii) CDR-H1 of SEQ ID NO: 9, CDR-H2 of SEQ ID NO: 10, CDR-H3 of SEQ ID NO: 11, CDR-L1 of SEQ ID NO: 12, CDR-L2 of SEQ ID NO: 13, and CDR-L3 of SEQ ID NO: 14; or (iii) CDR-H1 of sequence number 160, CDR-H2 of sequence number 161, CDR-H3 of sequence number 162, CDR-L1 of sequence number 163, CDR-L2 of sequence number 13, and CDR-L3 of sequence number 164 The composite, including the above.

2. The complex according to claim 1, wherein the anti-transferrin receptor antibody comprises a human or humanized framework region.

3. The complex according to claim 1 or 2, wherein the anti-transferrin receptor antibody comprises VH having an amino acid sequence at least 80% identical to SEQ ID NO: 15, and VL having an amino acid sequence at least 80% identical to SEQ ID NO:

16.

4. The complex according to any one of claims 1 to 3, wherein the anti-transferrin receptor antibody is selected from the group consisting of full-length IgG, Fab fragment, F(ab') fragment, F(ab')2 fragment, scFv, and Fv.

5. The complex according to any one of claims 1 to 4, wherein the anti-transferrin receptor antibody is a Fab fragment.

6. The complex according to any one of claims 1 to 5, wherein the anti-transferrin receptor antibody comprises a heavy chain containing an N-terminal pyroglutamic acid.

7. The complex according to any one of claims 1 to 6, wherein the molecular payload comprises an oligonucleotide.

8. The complex according to claim 7, wherein the oligonucleotide comprises at least one modified nucleoside linkage, and optionally, at least one modified nucleoside linkage is a phosphorothioate linkage.

9. The complex according to claim 8, wherein the linkages between each nucleoside of the oligonucleotide are phosphorothioate links.

10. The complex according to any one of claims 7 to 9, wherein the oligonucleotide comprises one or more modified nucleosides.

11. The complex according to claim 10, wherein one or more modified nucleosides are 2'-modified nucleosides.

12. The complex according to claim 11, wherein the 2'-modified nucleoside is selected from the group consisting of: 2'-O-methyl (2'-O-Me), 2'-fluoro (2'-F), 2'-O-methoxyethyl (2'-MOE), and 2',4'-bicyclic nucleosides.

13. The complex according to claim 12, wherein the 2',4'-bicyclic nucleoside is selected from: locked nucleic acid (LNA), ethylene-bridged nucleic acid (ENA), and (S)-restricted ethyl-bridged nucleic acid (cEt).

14. The complex according to any one of claims 7 to 13, wherein the oligonucleotide is a gapmer oligonucleotide that leads to RNAse H-mediated cleavage of mRNA transcripts encoded by muscle disease genes in cells, or an RNAi oligonucleotide that promotes RNAi-mediated cleavage of mRNA transcripts encoded by muscle disease genes.

15. The complex according to any one of claims 7 to 13, wherein the oligonucleotide is a mixmer oligonucleotide or a phosphorodiamidate morpholino oligomer.

16. The complex according to any one of claims 1 to 15, wherein the muscle disease gene is selected from GAA, GYS1, DNM2, DMD, DUX4, MYBPC3, MYH6, MYH7, TNNI3, TNNT2, ACVR1, FXN, GNE, MYH7, BAG3, CRYAB, DES, DNAJB6, FHL1, FLNC, LDB3, MYOT, PLEC, TTN, CLCN1, DMPK, CNBP, MTM1, PABPN1, and SCN4A.

17. The complex according to any one of claims 1 to 16, wherein the muscle disease gene is selected from DMD, DUX4, and DMPK.

18. The complex according to any one of claims 1 to 17, wherein an anti-transferrin receptor antibody is covalently linked to a molecular payload via a cleavable linker.

19. The complex according to claim 18, wherein the cleavable linker comprises a valine-citrulline sequence.

20. The complex according to any one of claims 1 to 17, wherein an anti-transferrin receptor antibody is covalently linked to a molecular payload via an inclementable linker.

21. The composite according to claim 20, wherein the inseparable linker is an alkane linker.

22. The complex according to any one of claims 1 to 21, wherein the molecular payload is linked to an anti-transferrin receptor antibody via a lysine residue of the antibody.

23. The complex according to any one of claims 1 to 21, wherein the molecular payload is linked to an anti-transferrin receptor antibody via a cysteine ​​residue of the antibody.

24. A composite according to any one of claims 1 to 23, for use in treatment.

25. A complex according to any one of claims 1 to 23, for use in a method of treating a disease or condition that can be improved or prevented by inhibiting the expression or activity of muscle disease genes in cells, wherein the method comprises bringing cells into contact with the complex.

26. A complex according to any one of claims 1 to 23 for use in a method of treating a subject having a muscle disease, wherein the method comprises administering the complex to the subject.

27. The complex according to claim 25, wherein the muscle disease is Pompe disease, central nucleus myopathy (CNM), Duchenne muscular dystrophy, familial scapular-brachial muscular dystrophy (FSHD), familial hypertrophic cardiomyopathy, fibrodysplasia ossificans progressive (FOP), ataxia Friedreich (FRDA), type II inclusion body myopathy, distal Rein myopathy, myofibril myopathy, congenital myotonia (autosomal dominant type), Thomsen's disease, myotonic dystrophy type I, myotonic dystrophy type II, myotyl myopathy, oculopharyngeal muscular dystrophy, or congenital anomalous myotonia.

28. The complex according to any one of claims 26 or 27, wherein the muscle disease is Pompe disease, DM1, DMD, or FSHD.

29. The composite according to any one of claims 26 to 28, wherein the subject is a human.

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