Antibody or antigen-binding fragment thereof, in vitro method for reducing myostatin receptor activation in cells, pharmaceutical composition, syringe and nucleic acid.

Abstract

 

Description

Antibody or antigen-binding fragment thereof, in vitro method for reducing myostatin receptor activation in cells, pharmaceutical composition, syringe and nucleic acid. CROSS-REFERENCE WITH RELATED REQUEST

[001] This application claims priority under 35 USC § 119(e) of U.S. Provisional Patent Application No. 62 / 219,094, filed September 15, 2015, and entitled “ANTIPRO / LATENTMYOSTATIN ANTIBODIES AND USES THEREOF”, the contents of which are incorporated herein by reference for all purposes. FIELD OF REVELATION

[002] Embodiments of the present disclosure may include growth factor activity modulators. In some embodiments, these modulators may include antibodies and may modulate the activity and / or biology of a member of the TGF-β family. FOUNDATIONS OF REVELATION

[003] Myostatin is a secreted growth factor that negatively regulates muscle mass. Loss-of-function mutations in the myostatin gene, leading to a hypermuscular phenotype, have been described in cattle, sheep, fish, dogs, and humans. Myostatin expression is generally limited to skeletal muscle, with low expression levels reported in adipose and cardiac tissues. Inhibition of myostatin signaling leads to an increase in muscle size. SUMMARY OF REVELATION

[004] Aspects of the revelation are related, in some modalities, to antibodies that bind specifically to forms of myostatin (e.g., promyostatin and / or latent myostatin). For example, the Petition 870260028601, dated 03 / 26 / 2026, page 11 / 18 2 / 190 antibodies provided in this descriptive report specifically bind to one or more pro-forms and / or latent forms of myostatin, for example, promyostatin and / or latent myostatin. In certain aspects, the discovery is based on the surprising finding of antibodies provided in this descriptive report that specifically bind to pure or substantially pure pro-GDF8 (also referred to as promyostatin). In some embodiments, the antibodies provided in this descriptive report inhibit myostatin signaling. In some embodiments, the inhibition of myostatin signaling is useful for increasing muscle mass or preventing muscle atrophy. In some embodiments, the antibodies provided in this descriptive report bind to and prevent the cleavage of myostatin by a proprotein convertase and / or a toloid protease. The prevention of the cleavage of promyostatin or latent myostatin, in some embodiments, prevents the activation of myostatin.Additional aspects of the disclosure relate to antibodies that have an affinity for an antigen that is pH-sensitive. In some embodiments, these pH-sensitive antibodies are effective for clearing antigens from serum. Furthermore, in some embodiments, the antibodies provided in this descriptive report are sweeping antibodies that can efficiently clear antigens (e.g., promyostatin and / or latent myostatin) from serum.

[005] Aspects of the present disclosure include an antibody comprising a variable heavy chain domain and a variable light chain domain, wherein the variable heavy chain domain comprises a complementarity-determining region 3 (CDRH3) comprising a sequence as presented in either of the IDS. DE SEQ. Nos: 10-11. Petition 870210013044, dated 08 / 02 / 2021, page 12 / 205 2 / 190 antibodies provided in this descriptive report specifically bind to one or more pro-forms and / or latent forms of myostatin, for example, promyostatin and / or latent myostatin. In certain aspects, the discovery is based on the surprising finding of antibodies provided in this descriptive report that specifically bind to pure or substantially pure pro-GDF8 (also referred to as promyostatin). In some embodiments, the antibodies provided in this descriptive report inhibit myostatin signaling. In some embodiments, the inhibition of myostatin signaling is useful for increasing muscle mass or preventing muscle atrophy. In some embodiments, the antibodies provided in this descriptive report bind to and prevent the cleavage of myostatin by a proprotein convertase and / or a toloid protease. The prevention of the cleavage of promyostatin or latent myostatin, in some embodiments, prevents the activation of myostatin.Additional aspects of the disclosure relate to antibodies that have an affinity for an antigen that is pH-sensitive. In some embodiments, these pH-sensitive antibodies are effective for clearing antigens from serum. Furthermore, in some embodiments, the antibodies provided in this descriptive report are sweeping antibodies that can efficiently clear antigens (e.g., promyostatin and / or latent myostatin) from serum.

[005] Aspects of the present disclosure include an antibody comprising a variable heavy chain domain and a variable light chain domain, wherein the variable heavy chain domain comprises a complementarity-determining region 3 (CDRH3) comprising a sequence as presented in either of the IDS. DE SEQ. Nos: 10-11. Petition 870210013044, dated 08 / 02 / 2021, page 12 / 205 3 / 190 In some embodiments, an antibody binds specifically to promyostatin / latent myostatin. In some embodiments, the variable domain of the light chain comprises a complementarity-determining region 3 (CDRL3) comprising a sequence as shown in any of the IDS. SEQ. Nos: 22-23. In another embodiment, said antibody comprises six complementarity-determining regions (CDRs): CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3, wherein CDRH1 comprises a sequence as shown in any of the IDS. SEQ. Nos: 1-3, CDRH2 comprises a sequence as shown in any of the IDS. SEQ. Nos: 4-9, CDRH3 comprises a sequence as shown in any of the IDS. SEQ. Nos: 10-11, CDRL1 comprises a sequence as shown in any of the IDS. Nos: 12-17, CDRL2 comprises a sequence as shown in any of the IDS. DE SEQ. Nos: 18-21, and CDRL3 comprises a sequence as shown in any of the IDS.DE SEQ. Nos: 22-23.

[006] In some embodiments, said CDRH1 comprises a sequence as shown in ID. DE SEQ. N°: 1 or 2, CDRH2 comprises a sequence as shown in ID. DE SEQ. N°: 4 or 5, CDRH3 comprises a sequence as shown in ID. DE SEQ. N°: 10, CDRL1 comprises a sequence as shown in ID. DE SEQ. N°: 12 or 13, CDRL2 comprises a sequence as shown in ID. DE SEQ. N°: 18 or 19, and CDRL3 comprises a sequence as shown in ID. DE SEQ. N°: 22.

[007] In another embodiment, the aforementioned CDRH1 comprises a sequence as presented in ID. DE SEQ. N°: 1 or 3, CDRH2 comprises a sequence as shown in ID. DE Petition 870210013044, dated 08 / 02 / 2021, p. 13 / 205 3 / 190 In some embodiments, an antibody binds specifically to promyostatin / latent myostatin. In some embodiments, the variable domain of the light chain comprises a complementarity-determining region 3 (CDRL3) comprising a sequence as shown in any of the IDS. SEQ. Nos: 22-23. In another embodiment, said antibody comprises six complementarity-determining regions (CDRs): CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3, wherein CDRH1 comprises a sequence as shown in any of the IDS. SEQ. Nos: 1-3, CDRH2 comprises a sequence as shown in any of the IDS. SEQ. Nos: 4-9, CDRH3 comprises a sequence as shown in any of the IDS. SEQ. Nos: 10-11, CDRL1 comprises a sequence as shown in any of the IDS. Nos: 12-17, CDRL2 comprises a sequence as shown in any of the IDS. DE SEQ. Nos: 18-21, and CDRL3 comprises a sequence as shown in any of the IDS.DE SEQ. Nos: 22-23.

[006] In some embodiments, said CDRH1 comprises a sequence as shown in ID. DE SEQ. N°: 1 or 2, CDRH2 comprises a sequence as shown in ID. DE SEQ. N°: 4 or 5, CDRH3 comprises a sequence as shown in ID. DE SEQ. N°: 10, CDRL1 comprises a sequence as shown in ID. DE SEQ. N°: 12 or 13, CDRL2 comprises a sequence as shown in ID. DE SEQ. N°: 18 or 19, and CDRL3 comprises a sequence as shown in ID. DE SEQ. N°: 22.

[007] In another embodiment, the aforementioned CDRH1 comprises a sequence as presented in ID. DE SEQ. N°: 1 or 3, CDRH2 comprises a sequence as shown in ID. DE Petition 870210013044, dated 08 / 02 / 2021, p. 13 / 205 4 / 190 SEQ. N°: 6 or 7, CDRH3 comprises a sequence as presented in ID. DE SEQ. N°: 11, CDRL1 comprises a sequence as presented in ID. DE SEQ. N°: 14 or 15, CDRL2 comprises a sequence as presented in ID. DE SEQ. N°: 20 or 21, and CDRL3 comprises a sequence as presented in ID. DE SEQ. N°: 23.

[008] In other embodiments, CDRH1 comprises a sequence as presented in ID. DE SEQ. N°: 1 or 3, CDRH2 comprises a sequence as presented in ID. DE SEQ. N°: 8 or 9, CDRH3 comprises a sequence as presented in ID. DE SEQ. N°: 11, CDRL1 comprises a sequence as presented in ID. DE SEQ. N°: 16 or 17, CDRL2 comprises a sequence as presented in ID. DE SEQ. N°: 20 or 21, and CDRL3 comprises a sequence as presented in ID. DE SEQ. N°: 23.

[009] In another embodiment, said antibody comprises a variable domain sequence of the heavy chain as presented in any of the IDS. DE SEQ. Nos: 25-29. In some embodiments, said antibody comprises a variable domain sequence of the light chain as presented in any of the IDS. DE SEQ. Nos: 30-35.

[0010] Other aspects of the disclosure include an antibody that specifically binds to promyostatin / latent myostatin and that comprises a variable heavy chain domain and a variable light chain domain, wherein the variable light chain domain comprises a complementarity-determining region 3 (CDRL3) comprising a sequence as presented in either of the IDs. DE SEQ. Nos: 22-23. In some embodiments, said antibody comprises a sequence of the variable light chain domain of the ID. DE SEQ. Petition 870210013044, dated 08 / 02 / 2021, page 14 / 205 4 / 190 SEQ. N°: 6 or 7, CDRH3 comprises a sequence as presented in ID. DE SEQ. N°: 11, CDRL1 comprises a sequence as presented in ID. DE SEQ. N°: 14 or 15, CDRL2 comprises a sequence as presented in ID. DE SEQ. N°: 20 or 21, and CDRL3 comprises a sequence as presented in ID. DE SEQ. N°: 23.

[008] In other embodiments, CDRH1 comprises a sequence as presented in ID. DE SEQ. N°: 1 or 3, CDRH2 comprises a sequence as presented in ID. DE SEQ. N°: 8 or 9, CDRH3 comprises a sequence as presented in ID. DE SEQ. N°: 11, CDRL1 comprises a sequence as presented in ID. DE SEQ. N°: 16 or 17, CDRL2 comprises a sequence as presented in ID. DE SEQ. N°: 20 or 21, and CDRL3 comprises a sequence as presented in ID. DE SEQ. N°: 23.

[009] In another embodiment, said antibody comprises a variable domain sequence of the heavy chain as presented in any of the IDS. DE SEQ. Nos: 25-29. In some embodiments, said antibody comprises a variable domain sequence of the light chain as presented in any of the IDS. DE SEQ. Nos: 30-35.

[0010] Other aspects of the disclosure include an antibody that specifically binds to promyostatin / latent myostatin and that comprises a variable heavy chain domain and a variable light chain domain, wherein the variable light chain domain comprises a complementarity-determining region 3 (CDRL3) comprising a sequence as presented in either of the IDs. DE SEQ. Nos: 22-23. In some embodiments, said antibody comprises a sequence of the variable light chain domain of the ID. DE SEQ. Petition 870210013044, dated 08 / 02 / 2021, page 14 / 205 5 / 190 No. 30.

[0011] Some aspects of the disclosure relate to a polypeptide having a sequence selected from the group consisting of SEQ. ID. NO.: 24, SEQ. ID. NO.: 25, SEQ. ID. NO.: 26, SEQ. ID. NO.: 27, SEQ. ID. NO.: 28, and SEQ. ID. NO.: 29. In some embodiments, the polypeptide is a variable heavy chain domain. In some embodiments, the polypeptide is at least 75% (e.g., 80%, 85%, 90%, 95%, 98%, or 99%) identical to any of the amino acid sequences shown in SEQ. ID. NO.: 24, SEQ. ID. NO.: 25, SEQ. ID. NO.: 26, SEQ. ID. NO.: 27, SEQ. ID. NO.: 28, or SEQ. ID. FROM SEQ. NO. 29.

[0012] Some aspects of the disclosure relate to a polypeptide having a sequence selected from the group consisting of SEQ. ID. NO.: 30, SEQ. ID. NO.: 31, SEQ. ID. NO.: 32, SEQ. ID. NO.: 33, SEQ. ID. NO.: 34, and SEQ. ID. NO.: 35. In some embodiments, the polypeptide is a variable light chain domain. In some embodiments, the polypeptide is at least 75% (e.g., 80%, 85%, 90%, 95%, 98%, or 99%) identical to any of the amino acid sequences shown in SEQ. ID. NO.: 30, SEQ. ID. NO.: 31, SEQ. ID. NO.: 32, SEQ. ID. NO.: 33, SEQ. ID. NO.: 34, or SEQ. ID. FROM SEQ. NO. 35.

[0013] Another aspect of the revelation involves an antibody that competes for binding to promyostatin / latent myostatin with an antibody described above. In some embodiments, said antibody binds to promyostatin / latent myostatin at the same epitope as an antibody described above. In another embodiment, an antibody competes for binding to promyostatin / latent myostatin with a constant of Petition 870210013044, dated 08 / 02 / 2021, p. 15 / 205 5 / 190 No. 30.

[0011] Some aspects of the disclosure relate to a polypeptide having a sequence selected from the group consisting of SEQ. ID. NO.: 24, SEQ. ID. NO.: 25, SEQ. ID. NO.: 26, SEQ. ID. NO.: 27, SEQ. ID. NO.: 28, and SEQ. ID. NO.: 29. In some embodiments, the polypeptide is a variable heavy chain domain. In some embodiments, the polypeptide is at least 75% (e.g., 80%, 85%, 90%, 95%, 98%, or 99%) identical to any of the amino acid sequences shown in SEQ. ID. NO.: 24, SEQ. ID. NO.: 25, SEQ. ID. NO.: 26, SEQ. ID. NO.: 27, SEQ. ID. NO.: 28, or SEQ. ID. FROM SEQ. NO. 29.

[0012] Some aspects of the disclosure relate to a polypeptide having a sequence selected from the group consisting of SEQ. ID. NO.: 30, SEQ. ID. NO.: 31, SEQ. ID. NO.: 32, SEQ. ID. NO.: 33, SEQ. ID. NO.: 34, and SEQ. ID. NO.: 35. In some embodiments, the polypeptide is a variable light chain domain. In some embodiments, the polypeptide is at least 75% (e.g., 80%, 85%, 90%, 95%, 98%, or 99%) identical to any of the amino acid sequences shown in SEQ. ID. NO.: 30, SEQ. ID. NO.: 31, SEQ. ID. NO.: 32, SEQ. ID. NO.: 33, SEQ. ID. NO.: 34, or SEQ. ID. FROM SEQ. NO. 35.

[0013] Another aspect of the revelation involves an antibody that competes for binding to promyostatin / latent myostatin with an antibody described above. In some embodiments, said antibody binds to promyostatin / latent myostatin at the same epitope as an antibody described above. In another embodiment, an antibody competes for binding to promyostatin / latent myostatin with a constant of Petition 870210013044, dated 08 / 02 / 2021, p. 15 / 205 6 / 190 equilibrium dissociation, Kd, ​​between the antibody and promyostatin / latent myostatin that is less than 10⁻⁶ M. In other embodiments, the aforementioned Kd of the antibody is in a range of 10⁻¹¹ M to 10⁻⁶ M.

[0014] In some embodiments, an antibody is a humanized antibody, a diabody, a chimeric antibody, a Fab fragment, an F(ab')2 fragment, or an Fv fragment. In another embodiment, an antibody is a humanized antibody. In another embodiment, an antibody is a human antibody. In some embodiments, an antibody comprises a scaffold that has a human germline sequence. In another embodiment, an antibody comprises a heavy chain constant domain selected from the group consisting of IgG, IgG1, IgG2, IgG2A, IgG2B, IgG2C, IgG3, IgG4, IgA1, IgA2, IgD, IgM, and IgE constant domains. In some embodiments, an antibody comprises an IgG4 constant domain. In other embodiments, an antibody comprises an IgG4 constant domain that has a Ser-to-Pro scaffold substitution that produces an IgG1-like hinge and allows the formation of interchain disulfide bonds.In another embodiment, an antibody is conjugated to an agent selected from a group consisting of a fluorescent agent, a luminescent agent, an enzymatic agent, and a radioactive agent.

[0015] In another embodiment, an antibody binds specifically to promyostatin / latent myostatin compared to mature myostatin. In some embodiments, an antibody binds specifically to promyostatin / latent myostatin compared to another member of the transforming growth factor beta family. In Petition 870210013044, dated 08 / 02 / 2021, p. 16 / 205 6 / 190 equilibrium dissociation, Kd, ​​between the antibody and promyostatin / latent myostatin that is less than 10⁻⁶ M. In other embodiments, the aforementioned Kd of the antibody is in a range of 10⁻¹¹ M to 10⁻⁶ M.

[0014] In some embodiments, an antibody is a humanized antibody, a diabody, a chimeric antibody, a Fab fragment, an F(ab')2 fragment, or an Fv fragment. In another embodiment, an antibody is a humanized antibody. In another embodiment, an antibody is a human antibody. In some embodiments, an antibody comprises a scaffold that has a human germline sequence. In another embodiment, an antibody comprises a heavy chain constant domain selected from the group consisting of IgG, IgG1, IgG2, IgG2A, IgG2B, IgG2C, IgG3, IgG4, IgA1, IgA2, IgD, IgM, and IgE constant domains. In some embodiments, an antibody comprises an IgG4 constant domain. In other embodiments, an antibody comprises an IgG4 constant domain that has a Ser-to-Pro scaffold substitution that produces an IgG1-like hinge and allows the formation of interchain disulfide bonds.In another embodiment, an antibody is conjugated to an agent selected from a group consisting of a fluorescent agent, a luminescent agent, an enzymatic agent, and a radioactive agent.

[0015] In another embodiment, an antibody binds specifically to promyostatin / latent myostatin compared to mature myostatin. In some embodiments, an antibody binds specifically to promyostatin / latent myostatin compared to another member of the transforming growth factor beta family. In Petition 870210013044, dated 08 / 02 / 2021, p. 16 / 205 7 / 190 another modality, the aforementioned member is GDF11 or Activina.

[0016] An additional aspect of the disclosure includes an antibody that specifically binds to promyostatin / latent myostatin and inhibits the proteolytic formation of mature myostatin by a toloid protease. In some embodiments, said antibody inhibits the proteolytic formation of mature myostatin by a toloid protease with an IC50 of less than 1 μM. In some embodiments, an antibody cross-reacts with human and murine promyostatin / latent myostatin. In other embodiments, the antibody specifically binds to promyostatin / latent myostatin compared to GDF11 or Activin. In another embodiment, an antibody specifically binds to promyostatin / latent myostatin compared to mature myostatin.

[0017] Another aspect of the disclosure involves a method for reducing myostatin receptor activation in cells present in a medium comprising promyostatin / latent myostatin, the method comprising releasing into the medium an antibody described above in an amount effective for inhibiting the proteolytic activation of promyostatin / latent myostatin. In some embodiments, the medium further comprises a proprotein convertase. In other embodiments, the medium further comprises a toloid protease. In another embodiment, an antibody is released into the medium in an amount effective for inhibiting the proteolytic activation of promyostatin / latent myostatin by the toloid protease. In some embodiments, the cell is in vitro. In other embodiments, the cell is in vivo.

[0018] Another aspect of revelation includes a method of Petition 870210013044, dated 08 / 02 / 2021, page 17 / 205 7 / 190 another modality, the aforementioned member is GDF11 or Activina.

[0016] An additional aspect of the disclosure includes an antibody that specifically binds to promyostatin / latent myostatin and inhibits the proteolytic formation of mature myostatin by a toloid protease. In some embodiments, said antibody inhibits the proteolytic formation of mature myostatin by a toloid protease with an IC50 of less than 1 μM. In some embodiments, an antibody cross-reacts with human and murine promyostatin / latent myostatin. In other embodiments, the antibody specifically binds to promyostatin / latent myostatin compared to GDF11 or Activin. In another embodiment, an antibody specifically binds to promyostatin / latent myostatin compared to mature myostatin.

[0017] Another aspect of the disclosure involves a method for reducing myostatin receptor activation in cells present in a medium comprising promyostatin / latent myostatin, the method comprising releasing into the medium an antibody described above in an amount effective for inhibiting the proteolytic activation of promyostatin / latent myostatin. In some embodiments, the medium further comprises a proprotein convertase. In other embodiments, the medium further comprises a toloid protease. In another embodiment, an antibody is released into the medium in an amount effective for inhibiting the proteolytic activation of promyostatin / latent myostatin by the toloid protease. In some embodiments, the cell is in vitro. In other embodiments, the cell is in vivo.

[0018] Another aspect of revelation includes a method of Petition 870210013044, dated 08 / 02 / 2021, page 17 / 205 8 / 190 treatment of an individual who has a myopathy, the method comprising administering to the individual an effective amount of an antibody described above. In some modalities, the myopathy is a primary myopathy. In another modality, the primary myopathy comprises disuse atrophy. In other modalities, disuse atrophy is associated with hip fracture, elective joint replacement, intensive care myopathy, spinal cord injury, or stroke. In some modalities, the myopathy is a secondary myopathy, in which muscle loss is secondary to a disease pathology. In other modalities, the secondary myopathy comprises denervation, genetic muscle weakness, or cachexia. In another modality, the secondary myopathy is denervation associated with amyotrophic lateral sclerosis or spinal muscular atrophy. In some modalities, the secondary myopathy is genetic muscle weakness associated with muscular dystrophy.In other forms, secondary myopathy is cachexia associated with kidney failure, AIDS, a heart condition, cancer, or aging.

[0019] Another aspect of the revelation includes a method of treating an individual who has an age-related disease or condition. Exemplary age-related diseases and conditions include, but are not limited to, sarcopenia (age-related muscle loss), frailty, and androgen deficiency.

[0020] Another aspect of the revelation includes a method of treating an individual who has a disease or condition related to disuse / trauma atrophy. Exemplary diseases and conditions related to disuse / trauma atrophy include, Petition 870210013044, dated 08 / 02 / 2021, page 18 / 205 8 / 190 treatment of an individual who has a myopathy, the method comprising administering to the individual an effective amount of an antibody described above. In some modalities, the myopathy is a primary myopathy. In another modality, the primary myopathy comprises disuse atrophy. In other modalities, disuse atrophy is associated with hip fracture, elective joint replacement, intensive care myopathy, spinal cord injury, or stroke. In some modalities, the myopathy is a secondary myopathy, in which muscle loss is secondary to a disease pathology. In other modalities, the secondary myopathy comprises denervation, genetic muscle weakness, or cachexia. In another modality, the secondary myopathy is denervation associated with amyotrophic lateral sclerosis or spinal muscular atrophy. In some modalities, the secondary myopathy is genetic muscle weakness associated with muscular dystrophy.In other forms, secondary myopathy is cachexia associated with kidney failure, AIDS, a heart condition, cancer, or aging.

[0019] Another aspect of the revelation includes a method of treating an individual who has an age-related disease or condition. Exemplary age-related diseases and conditions include, but are not limited to, sarcopenia (age-related muscle loss), frailty, and androgen deficiency.

[0020] Another aspect of the revelation includes a method of treating an individual who has a disease or condition related to disuse / trauma atrophy. Exemplary diseases and conditions related to disuse / trauma atrophy include, Petition 870210013044, dated 08 / 02 / 2021, page 18 / 205 9 / 190 without limitation, muscle weakness related to time spent in an intensive care unit (ICU), hip / joint replacement, hip fracture, stroke, bed rest, SCI, rotator cuff injury, knee joint replacement, bone fracture, and burns.

[0021] Another aspect of the disclosure includes a method of treating an individual who has a neurodegenerative disease or condition. Exemplary neurodegenerative diseases or conditions include, without limitation, spinal muscular atrophy and amyotrophic lateral sclerosis (ALS).

[0022] Another aspect of the revelation includes a method of treating an individual who has a disease or condition related to cachexia. Exemplary diseases and conditions related to cachexia include, but are not limited to, cancer, chronic heart failure, acquired immunodeficiency syndrome (AIDS), chronic obstructive pulmonary disease (COPD), and chronic kidney disease (CKD).

[0023] Another aspect of the disclosure includes a method of treating an individual who has a disease or condition related to rare diseases. Exemplary rare diseases and conditions include, without limitation, osteogenesis imperfecta, sporadic inclusion body myositis, and acute lymphoblastic leukemia.

[0024] Another aspect of the disclosure includes a method of treating an individual who has a disease or condition related to a metabolic disorder and / or body composition. In some modalities, the disease or condition is obesity (e.g., severe obesity), Prader-Willi syndrome, type II diabetes, or anorexia. However, additional diseases or conditions related to metabolic disorders Petition 870210013044, dated 08 / 02 / 2021, page 19 / 205 9 / 190 without limitation, muscle weakness related to time spent in an intensive care unit (ICU), hip / joint replacement, hip fracture, stroke, bed rest, SCI, rotator cuff injury, knee joint replacement, bone fracture, and burns.

[0021] Another aspect of the disclosure includes a method of treating an individual who has a neurodegenerative disease or condition. Exemplary neurodegenerative diseases or conditions include, without limitation, spinal muscular atrophy and amyotrophic lateral sclerosis (ALS).

[0022] Another aspect of the revelation includes a method of treating an individual who has a disease or condition related to cachexia. Exemplary diseases and conditions related to cachexia include, but are not limited to, cancer, chronic heart failure, acquired immunodeficiency syndrome (AIDS), chronic obstructive pulmonary disease (COPD), and chronic kidney disease (CKD).

[0023] Another aspect of the disclosure includes a method of treating an individual who has a disease or condition related to rare diseases. Exemplary rare diseases and conditions include, without limitation, osteogenesis imperfecta, sporadic inclusion body myositis, and acute lymphoblastic leukemia.

[0024] Another aspect of the disclosure includes a method of treating an individual who has a disease or condition related to a metabolic disorder and / or body composition. In some modalities, the disease or condition is obesity (e.g., severe obesity), Prader-Willi syndrome, type II diabetes, or anorexia. However, additional diseases or conditions related to metabolic disorders Petition 870210013044, dated 08 / 02 / 2021, page 19 / 205 10 / 190 and / or body composition are within the scope of this disclosure.

[0025] Another aspect of the disclosure includes a method of treating an individual who has a disease or condition related to congenital myopathies. Exemplary congenital myopathies include, without limitation, X-linked myotubular myopathy, autosomal dominant centronuclear myopathy, autosomal recessive centronuclear myopathy, nemaline myopathy, and congenital fiber-type disproportion myopathy.

[0026] Another aspect of the disclosure includes a method of treating an individual who has a disease or condition related to muscular dystrophies. Exemplary muscular dystrophies include, without limitation, Duchenne muscular dystrophies, Becker muscular dystrophies, facioscapulohumeral (FSH) muscular dystrophies, and pelvic and scapular girdle muscular dystrophies.

[0027] Another aspect of the disclosure includes a method of treating an individual who has a disease or condition related to the urogynecological tract, glottic disorders (stenosis), extraocular myopathy, carpal tunnel syndrome, Guillain-Barré syndrome, or osteosarcoma.

[0028] In some modalities, the treatment results in increased muscle strength in the individual. In other modalities, the treatment results in an improved metabolic state in the individual.

[0029] In some embodiments, an antibody is administered at a dose in a range of 0.1 mg / kg to 100 mg / kg. In another embodiment, an antibody is administered at a dose in a range of 0.3 mg / kg to 30 mg / kg.

[0030] In some forms, an antibody is Petition 870210013044, dated 08 / 02 / 2021, page 20 / 205 10 / 190 and / or body composition are within the scope of this disclosure.

[0025] Another aspect of the disclosure includes a method of treating an individual who has a disease or condition related to congenital myopathies. Exemplary congenital myopathies include, without limitation, X-linked myotubular myopathy, autosomal dominant centronuclear myopathy, autosomal recessive centronuclear myopathy, nemaline myopathy, and congenital fiber-type disproportion myopathy.

[0026] Another aspect of the disclosure includes a method of treating an individual who has a disease or condition related to muscular dystrophies. Exemplary muscular dystrophies include, without limitation, Duchenne muscular dystrophies, Becker muscular dystrophies, facioscapulohumeral (FSH) muscular dystrophies, and pelvic and scapular girdle muscular dystrophies.

[0027] Another aspect of the disclosure includes a method of treating an individual who has a disease or condition related to the urogynecological tract, glottic disorders (stenosis), extraocular myopathy, carpal tunnel syndrome, Guillain-Barré syndrome, or osteosarcoma.

[0028] In some modalities, the treatment results in increased muscle strength in the individual. In other modalities, the treatment results in an improved metabolic state in the individual.

[0029] In some embodiments, an antibody is administered at a dose in a range of 0.1 mg / kg to 100 mg / kg. In another embodiment, an antibody is administered at a dose in a range of 0.3 mg / kg to 30 mg / kg.

[0030] In some forms, an antibody is Petition 870210013044, dated 08 / 02 / 2021, page 20 / 205 11 / 190 administered to the individual intravenously. In other embodiments, an antibody is administered to the individual subcutaneously. In another embodiment, an antibody is administered to the individual on several occasions. In some embodiments, these multiple administrations are performed at least monthly. In another embodiment, these multiple administrations are performed at least weekly.

[0031] A further aspect of the disclosure includes a composition comprising any antibody described above and a carrier. In some embodiments, said carrier is a pharmaceutically acceptable carrier. In other embodiments, an antibody and carrier are in a lyophilized form. In another embodiment, an antibody and carrier are in solution. In some embodiments, an antibody and carrier are frozen. In other embodiments, an antibody and carrier are frozen at a temperature less than or equal to -65°C.

[0032] Other aspects of the revelation include an isolated nucleic acid encoding a protein comprising three complementarity-determining regions (CDRs): CDRH1, CDRH2, and CDRH3, wherein CDRH3 comprises a sequence as presented in ID. DE SEQ. No.: 10 or 11. In some embodiments, said CDRH1 comprises a sequence as shown in ID. DE SEQ. No.: 1, 2, or 3. In other embodiments, CDRH2 comprises a sequence as presented in any of ID. DE SEQ. Nos.: 4-9.

[0033] Another aspect of the present disclosure includes an isolated nucleic acid encoding a protein comprising three complementarity-determining regions. Petition 870210013044, dated 08 / 02 / 2021, p. 21 / 205 11 / 190 administered to the individual intravenously. In other embodiments, an antibody is administered to the individual subcutaneously. In another embodiment, an antibody is administered to the individual on several occasions. In some embodiments, these multiple administrations are performed at least monthly. In another embodiment, these multiple administrations are performed at least weekly.

[0031] A further aspect of the disclosure includes a composition comprising any antibody described above and a carrier. In some embodiments, said carrier is a pharmaceutically acceptable carrier. In other embodiments, an antibody and carrier are in a lyophilized form. In another embodiment, an antibody and carrier are in solution. In some embodiments, an antibody and carrier are frozen. In other embodiments, an antibody and carrier are frozen at a temperature less than or equal to -65°C.

[0032] Other aspects of the revelation include an isolated nucleic acid encoding a protein comprising three complementarity-determining regions (CDRs): CDRH1, CDRH2, and CDRH3, wherein CDRH3 comprises a sequence as presented in ID. DE SEQ. No.: 10 or 11. In some embodiments, said CDRH1 comprises a sequence as shown in ID. DE SEQ. No.: 1, 2, or 3. In other embodiments, CDRH2 comprises a sequence as presented in any of ID. DE SEQ. Nos.: 4-9.

[0033] Another aspect of the present disclosure includes an isolated nucleic acid encoding a protein comprising three complementarity-determining regions. Petition 870210013044, dated 08 / 02 / 2021, p. 21 / 205 12 / 190 (CDRs): CDRL1, CDRL2 and CDRL3, where CDRL3 comprises a sequence as shown in ID. DE SEQ. No.: 22. In some embodiments, said CDRL1 comprises a sequence as presented in any of the ID. DE SEQ. Nos: 12-17. In other embodiments, CDRL2 comprises a sequence as presented in any of the ID. DE SEQ. Nos: 18-21.

[0034] Additional aspects of the present disclosure include an isolated nucleic acid comprising a sequence as presented in any of the IDS. DE SEQ. Nos: 38-49.

[0035] Another aspect of the revelation includes an isolated cell comprising an isolated nucleic acid described above.

[0036] The present disclosure, in some respects, includes methods for evaluating a biological sample obtained from an individual who has a myopathy. In some embodiments, the method comprises: preparing an immune reaction mixture comprising protein from a biological sample obtained from the individual and an antibody that binds specifically to promyostatin / latent myostatin; maintaining the immune reaction mixture under conditions that allow binding complexes to form between the antibody and a promyostatin / latent myostatin; and determining the extent of binding complex formation.In some embodiments, the method comprises: the preparation of an immune reaction mixture comprising protein from a biological sample obtained from the individual and an antibody that binds specifically to promyostatin; maintenance of the immune reaction mixture under conditions that allow binding complexes between the antibody and a promyostatin to form; and determination of the extent of formation of these complexes. Petition 870210013044, dated 08 / 02 / 2021, p. 22 / 205 12 / 190 (CDRs): CDRL1, CDRL2 and CDRL3, where CDRL3 comprises a sequence as shown in ID. DE SEQ. No.: 22. In some embodiments, said CDRL1 comprises a sequence as presented in any of the ID. DE SEQ. Nos: 12-17. In other embodiments, CDRL2 comprises a sequence as presented in any of the ID. DE SEQ. Nos: 18-21.

[0034] Additional aspects of the present disclosure include an isolated nucleic acid comprising a sequence as presented in any of the IDS. DE SEQ. Nos: 38-49.

[0035] Another aspect of the revelation includes an isolated cell comprising an isolated nucleic acid described above.

[0036] The present disclosure, in some respects, includes methods for evaluating a biological sample obtained from an individual who has a myopathy. In some embodiments, the method comprises: preparing an immune reaction mixture comprising protein from a biological sample obtained from the individual and an antibody that binds specifically to promyostatin / latent myostatin; maintaining the immune reaction mixture under conditions that allow binding complexes to form between the antibody and a promyostatin / latent myostatin; and determining the extent of binding complex formation.In some embodiments, the method comprises: the preparation of an immune reaction mixture comprising protein from a biological sample obtained from the individual and an antibody that binds specifically to promyostatin; maintenance of the immune reaction mixture under conditions that allow binding complexes to form between the antibody and a promyostatin; and determination of the extent of formation of... Petition 870210013044, dated 08 / 02 / 2021, page 22 / 205 13 / 190 binding complex. In some embodiments, the method comprises: preparing an immune reaction mixture comprising protein from a biological sample obtained from the individual and an antibody that binds specifically to latent myostatin; maintaining the immune reaction mixture under conditions that allow binding complexes to form between the antibody and a latent myostatin; and determining the extent of binding complex formation. In some embodiments, the method comprises: preparing an immune reaction mixture comprising protein from a biological sample obtained from the individual and an antibody that binds specifically to mature myostatin; maintaining the immune reaction mixture under conditions that allow binding complexes to form between the antibody and a mature myostatin; and determining the extent of binding complex formation.

[0037] In one aspect, this descriptive report discloses an isolated antibody comprising a variable heavy chain region comprising an amino acid sequence of ID. DE SEQ. N°: 25 and a variable light chain region comprising an amino acid sequence of ID. DE SEQ. N°: 31. In one embodiment, the antibody comprises a heavy chain comprising an amino acid sequence of ID. DE SEQ. N°: 50. In another embodiment, the antibody comprises a light chain comprising an amino acid sequence of ID. DE SEQ. N°: 51.

[0038] In another aspect, this descriptive report reveals an isolated antibody comprising a variable region of the heavy chain comprising a sequence of Petition 870210013044, dated 08 / 02 / 2021, page 23 / 205 13 / 190 binding complex. In some embodiments, the method comprises: preparing an immune reaction mixture comprising protein from a biological sample obtained from the individual and an antibody that binds specifically to latent myostatin; maintaining the immune reaction mixture under conditions that allow binding complexes to form between the antibody and a latent myostatin; and determining the extent of binding complex formation. In some embodiments, the method comprises: preparing an immune reaction mixture comprising protein from a biological sample obtained from the individual and an antibody that binds specifically to mature myostatin; maintaining the immune reaction mixture under conditions that allow binding complexes to form between the antibody and a mature myostatin; and determining the extent of binding complex formation.

[0037] In one aspect, this descriptive report discloses an isolated antibody comprising a variable heavy chain region comprising an amino acid sequence of ID. DE SEQ. N°: 25 and a variable light chain region comprising an amino acid sequence of ID. DE SEQ. N°: 31. In one embodiment, the antibody comprises a heavy chain comprising an amino acid sequence of ID. DE SEQ. N°: 50. In another embodiment, the antibody comprises a light chain comprising an amino acid sequence of ID. DE SEQ. N°: 51.

[0038] In another aspect, this descriptive report reveals an isolated antibody comprising a variable region of the heavy chain comprising a sequence of Petition 870210013044, dated 08 / 02 / 2021, page 23 / 205 14 / 190 CDRH1 comprising sequence ID No. 1, a sequence of CDRH2 comprising sequence ID No. 6 and a sequence of CDRH3 comprising sequence ID No. 11; and a variable region of the light chain comprising a sequence of CDRL1 comprising sequence ID No. 14, a sequence of CDRL2 comprising sequence ID No. 20 and a sequence of CDRL3 comprising sequence ID No. 23.

[0039] In one embodiment, the variable region of the heavy chain comprises a sequence of ID. DE SEQ. N°: 26. In another embodiment, the variable region of the light chain comprises a sequence of ID. DE SEQ. N°: 32.

[0040] In one embodiment, the variable region of the heavy chain comprises a sequence of ID. DE SEQ. N°: 27. In another embodiment, the variable region of the light chain comprises a sequence of ID. DE SEQ. N°: 33.

[0041] In another aspect, this descriptive report discloses an isolated antibody comprising a variable region of the heavy chain comprising a CDRH1 sequence comprising ID. DE SEQ. N°: 1, a CDRH2 sequence comprising ID. DE SEQ. N°: 8 and a CDRH3 sequence comprising ID. DE SEQ. N°: 11; and a variable region of the light chain comprising a CDRL1 sequence comprising ID. DE SEQ. N°: 16, a CDRL2 sequence comprising ID. DE SEQ. N°: 20 and a CDRL3 sequence comprising ID. DE SEQ. N°: 23.

[0042] In one embodiment, the variable region of the heavy chain comprises a sequence of ID. DE SEQ. N°: 28. In another embodiment, the variable region of the light chain comprises a sequence of ID. DE SEQ. N°: 34.

[0043] In one embodiment, the variable region of the chain Petition 870210013044, dated 08 / 02 / 2021, page 24 / 205 14 / 190 CDRH1 comprising sequence ID No. 1, a sequence of CDRH2 comprising sequence ID No. 6 and a sequence of CDRH3 comprising sequence ID No. 11; and a variable region of the light chain comprising a sequence of CDRL1 comprising sequence ID No. 14, a sequence of CDRL2 comprising sequence ID No. 20 and a sequence of CDRL3 comprising sequence ID No. 23.

[0039] In one embodiment, the variable region of the heavy chain comprises a sequence of ID. DE SEQ. N°: 26. In another embodiment, the variable region of the light chain comprises a sequence of ID. DE SEQ. N°: 32.

[0040] In one embodiment, the variable region of the heavy chain comprises a sequence of ID. DE SEQ. N°: 27. In another embodiment, the variable region of the light chain comprises a sequence of ID. DE SEQ. N°: 33.

[0041] In another aspect, this descriptive report discloses an isolated antibody comprising a variable region of the heavy chain comprising a CDRH1 sequence comprising ID. DE SEQ. N°: 1, a CDRH2 sequence comprising ID. DE SEQ. N°: 8 and a CDRH3 sequence comprising ID. DE SEQ. N°: 11; and a variable region of the light chain comprising a CDRL1 sequence comprising ID. DE SEQ. N°: 16, a CDRL2 sequence comprising ID. DE SEQ. N°: 20 and a CDRL3 sequence comprising ID. DE SEQ. N°: 23.

[0042] In one embodiment, the variable region of the heavy chain comprises a sequence of ID. DE SEQ. N°: 28. In another embodiment, the variable region of the light chain comprises a sequence of ID. DE SEQ. N°: 34.

[0043] In one embodiment, the variable region of the chain Petition 870210013044, dated 08 / 02 / 2021, page 24 / 205 15 / 190 heavy comprises a sequence of ID. DE SEQ. N°: 29. In one embodiment, the variable region of the light chain comprises a sequence of ID. DE SEQ. N°: 35.

[0044] In one embodiment, the antibody is a human antibody. In one embodiment, the antibody comprises an IgG4 constant domain. In one embodiment, the antibody comprises an IgG4 constant domain that has a Ser-to-Pro backbone substitution that produces an IgG1-like hinge and allows the formation of interchain disulfide bonds.

[0045] In one embodiment, the antibody binds specifically to promyostatin / latent myostatin. In one embodiment, the antibody binds specifically to promyostatin. In another embodiment, the antibody binds specifically to latent myostatin. In one embodiment, the antibody does not bind to mature myostatin.

[0046] In one embodiment, the antibody inhibits the proteolytic formation of mature myostatin by toloid protease. In one embodiment, the antibody inhibits the proteolytic formation of mature myostatin by toloid protease with an IC50 of less than 1 μM.

[0047] In one embodiment, the antibody cross-reacts with human and murine promyostatin / latent myostatin. In another embodiment, the antibody binds to promyostatin / latent myostatin but does not bind to GDF11 or activin.

[0048] In one aspect, this descriptive report discloses a method for reducing myostatin receptor activation in cells present in a medium comprising promyostatin / latent myostatin, the method comprising releasing into the medium an antibody described in this report. Petition 870210013044, dated 08 / 02 / 2021, p. 25 / 205 15 / 190 heavy comprises a sequence of ID. DE SEQ. N°: 29. In one embodiment, the variable region of the light chain comprises a sequence of ID. DE SEQ. N°: 35.

[0044] In one embodiment, the antibody is a human antibody. In one embodiment, the antibody comprises an IgG4 constant domain. In one embodiment, the antibody comprises an IgG4 constant domain that has a Ser-to-Pro backbone substitution that produces an IgG1-like hinge and allows the formation of interchain disulfide bonds.

[0045] In one embodiment, the antibody binds specifically to promyostatin / latent myostatin. In one embodiment, the antibody binds specifically to promyostatin. In another embodiment, the antibody binds specifically to latent myostatin. In one embodiment, the antibody does not bind to mature myostatin.

[0046] In one embodiment, the antibody inhibits the proteolytic formation of mature myostatin by toloid protease. In one embodiment, the antibody inhibits the proteolytic formation of mature myostatin by toloid protease with an IC50 of less than 1 μM.

[0047] In one embodiment, the antibody cross-reacts with human and murine promyostatin / latent myostatin. In another embodiment, the antibody binds to promyostatin / latent myostatin but does not bind to GDF11 or activin.

[0048] In one aspect, this descriptive report discloses a method for reducing myostatin receptor activation in cells present in a medium comprising promyostatin / latent myostatin, the method comprising releasing into the medium an antibody described in this report. Petition 870210013044, dated 08 / 02 / 2021, p. 25 / 205 16 / 190 descriptive in an effective amount for inhibition of proteolytic activation of promyostatin / latent myostatin. In one embodiment, the medium comprises a proprotein convertase. In another embodiment, the medium comprises a toloid protease. In one embodiment, the cell is in vitro. In another embodiment, the cell is in vivo.

[0049] In another aspect, this descriptive report discloses a method of treating an individual who has a myopathy, the method comprising administering to the individual an effective amount of an antibody disclosed in this descriptive report.

[0050] In one modality, the myopathy is a primary myopathy. In another modality, the primary myopathy is disuse atrophy. In one modality, disuse atrophy is associated with hip fracture, elective joint replacement, intensive care myopathy, spinal cord injury, and / or stroke.

[0051] In another modality, myopathy is a secondary myopathy in which muscle loss is secondary to a disease pathology. In one modality, secondary myopathy comprises denervation, genetic muscle weakness, or cachexia. In another modality, secondary myopathy is denervation associated with amyotrophic lateral sclerosis or spinal muscular atrophy. In yet another modality, secondary myopathy is genetic muscle weakness associated with muscular dystrophy. In one modality, secondary myopathy is cachexia associated with renal failure, AIDS, a heart condition, cancer, or aging.

[0052] In one modality, the administration results in Petition 870210013044, dated 08 / 02 / 2021, page 26 / 205 16 / 190 descriptive in an effective amount for inhibition of proteolytic activation of promyostatin / latent myostatin. In one embodiment, the medium comprises a proprotein convertase. In another embodiment, the medium comprises a toloid protease. In one embodiment, the cell is in vitro. In another embodiment, the cell is in vivo.

[0049] In another aspect, this descriptive report discloses a method of treating an individual who has a myopathy, the method comprising administering to the individual an effective amount of an antibody disclosed in this descriptive report.

[0050] In one modality, the myopathy is a primary myopathy. In another modality, the primary myopathy is disuse atrophy. In one modality, disuse atrophy is associated with hip fracture, elective joint replacement, intensive care myopathy, spinal cord injury, and / or stroke.

[0051] In another modality, myopathy is a secondary myopathy in which muscle loss is secondary to a disease pathology. In one modality, secondary myopathy comprises denervation, genetic muscle weakness, or cachexia. In another modality, secondary myopathy is denervation associated with amyotrophic lateral sclerosis or spinal muscular atrophy. In yet another modality, secondary myopathy is genetic muscle weakness associated with muscular dystrophy. In one modality, secondary myopathy is cachexia associated with renal failure, AIDS, a heart condition, cancer, or aging.

[0052] In one modality, the administration results in Petition 870210013044, dated 08 / 02 / 2021, page 26 / 205 17 / 190 increased muscle strength in the individual. In one modality, administration results in an enhanced metabolic state in the individual.

[0053] In one embodiment, the antibody is administered at a dose in a range of 0.1 mg / kg to 100 mg / kg. In another embodiment, the antibody is administered at a dose in a range of 0.3 mg / kg to 30 mg / kg.

[0054] In one embodiment, the antibody is administered to the individual intravenously. In another embodiment, the antibody is administered to the individual subcutaneously.

[0055] In one embodiment, the antibody is administered to the individual on multiple occasions. In one embodiment, the multiple administrations are performed at least monthly. In another embodiment, the multiple administrations are performed at least weekly.

[0056] In another aspect, a pharmaceutical composition comprising an antibody disclosed in this descriptive report and a pharmaceutically acceptable carrier is disclosed in this descriptive report. In one embodiment, the composition is a lyophilized composition. In another embodiment, the composition is a liquid composition. In one embodiment, the composition is frozen. In one embodiment, the composition is frozen at a temperature less than or equal to -65°C.

[0057] In another aspect, a syringe comprising a pharmaceutical composition described in this descriptive report is disclosed in this descriptive report.

[0058] In another aspect, this descriptive report reveals an isolated nucleic acid encoding an antibody comprising a variable heavy chain region comprising a nucleic acid sequence of ID. DE Petition 870210013044, dated 08 / 02 / 2021, page 27 / 205 17 / 190 increased muscle strength in the individual. In one modality, administration results in an enhanced metabolic state in the individual.

[0053] In one embodiment, the antibody is administered at a dose in a range of 0.1 mg / kg to 100 mg / kg. In another embodiment, the antibody is administered at a dose in a range of 0.3 mg / kg to 30 mg / kg.

[0054] In one embodiment, the antibody is administered to the individual intravenously. In another embodiment, the antibody is administered to the individual subcutaneously.

[0055] In one embodiment, the antibody is administered to the individual on multiple occasions. In one embodiment, the multiple administrations are performed at least monthly. In another embodiment, the multiple administrations are performed at least weekly.

[0056] In another aspect, a pharmaceutical composition comprising an antibody disclosed in this descriptive report and a pharmaceutically acceptable carrier is disclosed in this descriptive report. In one embodiment, the composition is a lyophilized composition. In another embodiment, the composition is a liquid composition. In one embodiment, the composition is frozen. In one embodiment, the composition is frozen at a temperature less than or equal to -65°C.

[0057] In another aspect, a syringe comprising a pharmaceutical composition described in this descriptive report is disclosed in this descriptive report.

[0058] In another aspect, this descriptive report reveals an isolated nucleic acid encoding an antibody comprising a variable heavy chain region comprising a nucleic acid sequence of ID. DE Petition 870210013044, dated 08 / 02 / 2021, page 27 / 205 18 / 190 SEQ. N°: 39 and a variable region of the light chain comprising a nucleic acid sequence of ID. DE SEQ. N°: 45.

[0059] In another aspect, this descriptive report discloses an isolated nucleic acid encoding an antibody comprising a variable region of the heavy chain comprising a CDRH1 sequence comprising ID. DE SEQ. N°: 1, a CDRH2 sequence comprising ID. DE SEQ. N°: 6 and a CDRH3 sequence comprising ID. DE SEQ. N°: 11; and a variable region of the light chain comprising a CDRL1 sequence comprising ID. DE SEQ. N°: 14, a CDRL2 sequence comprising ID. DE SEQ. N°: 20 and a CDRL3 sequence comprising ID. DE SEQ. N°: 23.

[0060] In one embodiment, the variable region of the heavy chain comprises a sequence of ID. DE SEQ. N°: 40. In one embodiment, the variable region of the light chain comprises a sequence of ID. DE SEQ. N°: 46.

[0061] In one embodiment, the variable region of the heavy chain comprises a sequence of ID. DE SEQ. N°: 41. In another embodiment, the variable region of the light chain comprises a sequence of ID. DE SEQ. N°: 47.

[0062] In another aspect, this descriptive report discloses an isolated nucleic acid encoding an antibody comprising a variable heavy chain region comprising a CDRH1 sequence comprising ID. DE SEQ. N°: 1, a CDRH2 sequence comprising ID. DE SEQ. N°: 8 and a CDRH3 sequence comprising ID. DE SEQ. N°: 11; and a variable light chain region comprising a CDRL1 sequence comprising ID. DE Petition 870210013044, dated 08 / 02 / 2021, page 28 / 205 18 / 190 SEQ. N°: 39 and a variable region of the light chain comprising a nucleic acid sequence of ID. DE SEQ. N°: 45.

[0059] In another aspect, this descriptive report discloses an isolated nucleic acid encoding an antibody comprising a variable region of the heavy chain comprising a CDRH1 sequence comprising ID. DE SEQ. N°: 1, a CDRH2 sequence comprising ID. DE SEQ. N°: 6 and a CDRH3 sequence comprising ID. DE SEQ. N°: 11; and a variable region of the light chain comprising a CDRL1 sequence comprising ID. DE SEQ. N°: 14, a CDRL2 sequence comprising ID. DE SEQ. N°: 20 and a CDRL3 sequence comprising ID. DE SEQ. N°: 23.

[0060] In one embodiment, the variable region of the heavy chain comprises a sequence of ID. DE SEQ. N°: 40. In one embodiment, the variable region of the light chain comprises a sequence of ID. DE SEQ. N°: 46.

[0061] In one embodiment, the variable region of the heavy chain comprises a sequence of ID. DE SEQ. N°: 41. In another embodiment, the variable region of the light chain comprises a sequence of ID. DE SEQ. N°: 47.

[0062] In another aspect, this descriptive report discloses an isolated nucleic acid encoding an antibody comprising a variable heavy chain region comprising a CDRH1 sequence comprising ID. DE SEQ. N°: 1, a CDRH2 sequence comprising ID. DE SEQ. N°: 8 and a CDRH3 sequence comprising ID. DE SEQ. N°: 11; and a variable light chain region comprising a CDRL1 sequence comprising ID. DE Petition 870210013044, dated 08 / 02 / 2021, page 28 / 205 19 / 190 SEQ. N°: 16, a CDRL2 sequence comprising ID.DE SEQ. N°: 20 and a CDRL3 sequence comprising ID.DE SEQ. N°:23.

[0063] In one embodiment, the variable region of the heavy chain comprises a sequence of ID. DE SEQ. N°: 42. In another embodiment, the variable region of the light chain comprises a sequence of ID. DE SEQ. N°: 48.

[0064] In one embodiment, the variable region of the heavy chain comprises a sequence of ID. DE SEQ. N°: 43. In another embodiment, the variable region of the light chain comprises a sequence of ID. DE SEQ. N°: 49.

[0065] In another aspect, an isolated cell comprising an isolated nucleic acid described in this descriptive report is disclosed in this descriptive report. BRIEF DESCRIPTION OF THE FIGURES

[0066] FIGURES 1A-1B show the structure of the myostatin domain and pro-myostatin assembly. FIGURE 1A shows secreted myostatin as a proprotein, with an inhibitory prodomain, followed by a C-terminal growth factor domain, which exists as a disulfide-linked dimer. FIGURE 1B shows the precursor protein assembled in an inactive conformation in which the prodomain (dark gray) surrounds the growth factor (light gray) with a straitjacket assembly. This figure is an adaptation of the latent TGFpl structure (Shi et al., Nature). 2011).

[0067] FIGURE 2 shows that myostatin activation involves two distinct protease events, generating three main myostatin species. The precursor biosynthetic protein, promyostatin, is processed by two proteases. Petition 870210013044, dated 08 / 02 / 2021, page 29 / 205 19 / 190 SEQ. N°: 16, a CDRL2 sequence comprising ID.DE SEQ. N°: 20 and a CDRL3 sequence comprising ID.DE SEQ. N°:23.

[0063] In one embodiment, the variable region of the heavy chain comprises a sequence of ID. DE SEQ. N°: 42. In another embodiment, the variable region of the light chain comprises a sequence of ID. DE SEQ. N°: 48.

[0064] In one embodiment, the variable region of the heavy chain comprises a sequence of ID. DE SEQ. N°: 43. In another embodiment, the variable region of the light chain comprises a sequence of ID. DE SEQ. N°: 49.

[0065] In another aspect, an isolated cell comprising an isolated nucleic acid described in this descriptive report is disclosed in this descriptive report. BRIEF DESCRIPTION OF THE FIGURES

[0066] FIGURES 1A-1B show the structure of the myostatin domain and pro-myostatin assembly. FIGURE 1A shows secreted myostatin as a proprotein, with an inhibitory prodomain, followed by a C-terminal growth factor domain, which exists as a disulfide-linked dimer. FIGURE 1B shows the precursor protein assembled in an inactive conformation in which the prodomain (dark gray) surrounds the growth factor (light gray) with a straitjacket assembly. This figure is an adaptation of the latent TGFpl structure (Shi et al., Nature). 2011).

[0067] FIGURE 2 shows that myostatin activation involves two distinct protease events, generating three main myostatin species. The precursor biosynthetic protein, promyostatin, is processed by two proteases. Petition 870210013044, dated 08 / 02 / 2021, page 29 / 205 20 / 190 separated. The cleavage of promyostatin (and pro-GDF11) is performed by a proprotein convertase, for example, Furin / PACE3 (Paired Basic Amino Acid Cleavage Enzyme 3) or PCSK5 (Proprotein Convertase). Subtilisin / Kexin type 5), which cleaves at a conserved RXXR site between the prodomain and mature growth factor. This cleavage produces a latent complex, in which the mature growth factor is shielded from binding to its receptors by the prodomain. Activation and release of the active growth factor are achieved after cleavage by an additional BMP / toloid family protease, for example, TLL-2 (toloid-like protein 2) or BMP1 (bone morphogenetic protein 1). These cleavage events generate a mature form of myostatin, which can be called active myostatin or mature myostatin.

[0068] FIGURES 3A-3C show that Ab1 blocks the cleavage of promyostatin by members of the toloid family of proteases. Samples of latent myostatin, pre-incubated with increasing amounts of Ab1, were analyzed in a myostatin activation assay. After analysis of myostatin release by reporter assay (FIGURE 3A), the samples were then processed under reducing conditions and probed by Western blot with an evoked antibody against the myostatin prodomain (FIGURE 3B). A band of approximately 18 kDa (box), corresponding to the ARM portion of the prodomain generated after toloid cleavage, decreased proportionally with increasing doses of Ab1. The patterns of latent myostatin and promyostatin (45 ng loaded) show migration of promyostatin at approximately 50 kDa, and the prodomain at approximately 37 kDa. FIGURE 3C Petition 870210013044, dated 08 / 02 / 2021, page 30 / 205 20 / 190 separated. The cleavage of promyostatin (and pro-GDF11) is performed by a proprotein convertase, for example, Furin / PACE3 (Paired Basic Amino Acid Cleavage Enzyme 3) or PCSK5 (Proprotein Convertase). Subtilisin / Kexin type 5), which cleaves at a conserved RXXR site between the prodomain and mature growth factor. This cleavage produces a latent complex, in which the mature growth factor is shielded from binding to its receptors by the prodomain. Activation and release of the active growth factor are achieved after cleavage by an additional BMP / toloid family protease, for example, TLL-2 (toloid-like protein 2) or BMP1 (bone morphogenetic protein 1). These cleavage events generate a mature form of myostatin, which can be called active myostatin or mature myostatin.

[0068] FIGURES 3A-3C show that Ab1 blocks the cleavage of promyostatin by members of the toloid family of proteases. Samples of latent myostatin, pre-incubated with increasing amounts of Ab1, were analyzed in a myostatin activation assay. After analysis of myostatin release by reporter assay (FIGURE 3A), the samples were then processed under reducing conditions and probed by Western blot with an evoked antibody against the myostatin prodomain (FIGURE 3B). A band of approximately 18 kDa (box), corresponding to the ARM portion of the prodomain generated after toloid cleavage, decreased proportionally with increasing doses of Ab1. The patterns of latent myostatin and promyostatin (45 ng loaded) show migration of promyostatin at approximately 50 kDa, and the prodomain at approximately 37 kDa. FIGURE 3C Petition 870210013044, dated 08 / 02 / 2021, page 30 / 205 Figure 21 / 190 shows that myostatin activation involves two distinct protease events, generating three main myostatin species. The precursor biosynthetic protein, promyostatin, is processed by two separate proteases. Cleavage of promyostatin (and pro-GDF11) is performed by a proprotein convertase, for example, Furin / PACE3 (Basic Paired Amino Acid Cleavage Enzyme 3) or PCSK5 (Proprotein Convertase Subtilisin / Kexin type 5), which cleaves at a conserved RXXR site between the prodomain and mature growth factor. This cleavage produces a latent complex, in which mature growth factor is shielded from binding to its receptors by the prodomain. See FIGURE 3B, which illustrates the potential inhibition of a toloid protease, further blocking promyostatin cleavage.The activation and release of the active growth factor are achieved after cleavage by an additional BMP / toloid family protease, for example, TLL-2 (toloid-like protein 2) or BMP1 (bone morphogenetic protein 1).

[0069] FIGURE 4 shows the performance of the parental Ab1 antibody and other candidates in the cell-based reporter assay. After an overnight proteolysis reaction with enzymes from both the proprotein-convertase and toloid protease families, mature growth factor release was measured using a CAGA-based reporter assay in 293T cells. The results were compared with control reactions to calculate the fraction of promyostatin or proGDF11 that was released in the assay. The standard deviation for a mean of 3 replicates is shown, but not visible in the graph for most data points due to its low magnitude. Petition 870210013044, dated 08 / 02 / 2021, page 31 / 205 Figure 21 / 190 shows that myostatin activation involves two distinct protease events, generating three main myostatin species. The precursor biosynthetic protein, promyostatin, is processed by two separate proteases. Cleavage of promyostatin (and pro-GDF11) is performed by a proprotein convertase, for example, Furin / PACE3 (Basic Paired Amino Acid Cleavage Enzyme 3) or PCSK5 (Proprotein Convertase Subtilisin / Kexin type 5), which cleaves at a conserved RXXR site between the prodomain and mature growth factor. This cleavage produces a latent complex, in which mature growth factor is shielded from binding to its receptors by the prodomain. See FIGURE 3B, which illustrates the potential inhibition of a toloid protease, further blocking promyostatin cleavage.The activation and release of the active growth factor are achieved after cleavage by an additional BMP / toloid family protease, for example, TLL-2 (toloid-like protein 2) or BMP1 (bone morphogenetic protein 1).

[0069] FIGURE 4 shows the performance of the parental Ab1 antibody and other candidates in the cell-based reporter assay. After an overnight proteolysis reaction with enzymes from both the proprotein-convertase and toloid protease families, mature growth factor release was measured using a CAGA-based reporter assay in 293T cells. The results were compared with control reactions to calculate the fraction of promyostatin or proGDF11 that was released in the assay. The standard deviation for a mean of 3 replicates is shown, but not visible in the graph for most data points due to its low magnitude. Petition 870210013044, dated 08 / 02 / 2021, page 31 / 205 22 / 190

[0070] FIGURE 5 graphically shows that antibodies Ab1, Ab2, Ab4 and Ab6 do not inhibit the activation of pro-GDF11.

[0071] FIGURE 6 shows the results of a trial evaluating the mean percent change in body weight. Animals were weighed daily and the percent change in weight from Day 0 was calculated. Data represent group means ± SEM. The mean percent change data for each group on day 42 of the study were analyzed using a one-way ANOVA followed by a Holm-Sidak post-hoc test compared to the PBS control group, **p<0.01.

[0072] FIGURES 7A-7D show the results of a trial evaluating tissue weights. FIGURE 7A shows the average weight of the gastrocnemius. FIGURE 7B shows the average weight of the pectoralis major. FIGURE 7C shows the average weight of the soleus. FIGURE 7D shows the average weight of the triceps. Statistical evaluation was performed using a one-way ANOVA, followed by Holm-Sidak post-hoc test in comparison with the vehicle control group (Group 1). Data represent group means ± SEM. **p<0.01. Bars indicate Groups 1-5 from left to right.

[0073] FIGURES 8A-8C show the results of a trial evaluating tissue weights. FIGURE 8A shows the mean weight of the tibialis anterior. FIGURE 8B shows the mean weight of the diaphragm. FIGURE 8C shows the mean weight of the quadriceps. Statistical evaluation was performed using a one-way ANOVA followed by Holm-Sidak post-hoc test in comparison with the vehicle control group (Group 1). Data represent group means ± SEM. *p<0.05. Bars indicate Groups 1-5 from left to right.

[0074] FIGURES 9A-9B show the results of a Petition 870210013044, dated 08 / 02 / 2021, page 32 / 205 22 / 190

[0070] FIGURE 5 graphically shows that antibodies Ab1, Ab2, Ab4 and Ab6 do not inhibit the activation of pro-GDF11.

[0071] FIGURE 6 shows the results of a trial evaluating the mean percent change in body weight. Animals were weighed daily and the percent change in weight from Day 0 was calculated. Data represent group means ± SEM. The mean percent change data for each group on day 42 of the study were analyzed using a one-way ANOVA followed by a Holm-Sidak post-hoc test compared to the PBS control group, **p<0.01.

[0072] FIGURES 7A-7D show the results of a trial evaluating tissue weights. FIGURE 7A shows the average weight of the gastrocnemius. FIGURE 7B shows the average weight of the pectoralis major. FIGURE 7C shows the average weight of the soleus. FIGURE 7D shows the average weight of the triceps. Statistical evaluation was performed using a one-way ANOVA, followed by Holm-Sidak post-hoc test in comparison with the vehicle control group (Group 1). Data represent group means ± SEM. **p<0.01. Bars indicate Groups 1-5 from left to right.

[0073] FIGURES 8A-8C show the results of a trial evaluating tissue weights. FIGURE 8A shows the mean weight of the tibialis anterior. FIGURE 8B shows the mean weight of the diaphragm. FIGURE 8C shows the mean weight of the quadriceps. Statistical evaluation was performed using a one-way ANOVA followed by Holm-Sidak post-hoc test in comparison with the vehicle control group (Group 1). Data represent group means ± SEM. *p<0.05. Bars indicate Groups 1-5 from left to right.

[0074] FIGURES 9A-9B show the results of a Petition 870210013044, dated 08 / 02 / 2021, page 32 / 205 Figure 9A is a graph showing the calculated percent change in weight from Day 0 in animals weighed twice weekly throughout the study. In Figure 9B, animals underwent EchoMRI (QMRN) to measure body composition on days -4, 7, 14, 21, and 28, and the percent change in lean mass from Day 0 was calculated. Data represent group means ± SEM. For both body weight and lean mass, the mean percent change data for each group on day 28 of the study were analyzed using a one-way ANOVA followed by a Holm-Sidak post-hoc test compared to the IgG control group (Group 2). ***p<0.0005, **p<0.005, *p<0.05, ns (not significant).

[0075] FIGURES 10A-10D are graphs showing the results of a trial evaluating muscle weights. FIGURE 10A shows the average weight of the quadriceps, FIGURE 10B shows the average weight of the gastrocnemius, FIGURE 10C shows the average weight of the tibialis anterior, and FIGURE 10D shows the average weight of the diaphragm. The percentage difference in average muscle weights of the Ab1-treated groups compared to the IgG control group is shown above each bar. Statistical analysis was performed using a one-way ANOVA followed by a Holm-Sidak post-hoc test compared to the IgG control group (Group 2). Data represent group means ± SEM. ****p<0.0001, ***p<0.0005, **p<0.005, *p<0.05, ns (not significant).

[0076] FIGURES 11A-11B show the results of a trial evaluating average percent body weight and change in lean mass. FIGURE 11A shows the change Petition 870210013044, dated 08 / 02 / 2021, page 33 / 205 Figure 9A is a graph showing the calculated percent change in weight from Day 0 in animals weighed twice weekly throughout the study. In Figure 9B, animals underwent EchoMRI (QMRN) to measure body composition on days -4, 7, 14, 21, and 28, and the percent change in lean mass from Day 0 was calculated. Data represent group means ± SEM. For both body weight and lean mass, the mean percent change data for each group on day 28 of the study were analyzed using a one-way ANOVA followed by a Holm-Sidak post-hoc test compared to the IgG control group (Group 2). ***p<0.0005, **p<0.005, *p<0.05, ns (not significant).

[0075] FIGURES 10A-10D are graphs showing the results of a trial evaluating muscle weights. FIGURE 10A shows the average weight of the quadriceps, FIGURE 10B shows the average weight of the gastrocnemius, FIGURE 10C shows the average weight of the tibialis anterior, and FIGURE 10D shows the average weight of the diaphragm. The percentage difference in average muscle weights of the Ab1-treated groups compared to the IgG control group is shown above each bar. Statistical analysis was performed using a one-way ANOVA followed by a Holm-Sidak post-hoc test compared to the IgG control group (Group 2). Data represent group means ± SEM. ****p<0.0001, ***p<0.0005, **p<0.005, *p<0.05, ns (not significant).

[0076] FIGURES 11A-11B show the results of a trial evaluating average percent body weight and change in lean mass. FIGURE 11A shows the change Petition 870210013044, dated 08 / 02 / 2021, page 33 / 205 24 / 190 percent change in weight from Day 0 calculated from animals weighed twice weekly throughout the study. (FIGURE 11B) Animals underwent EchoMRI (QMRN) to measure body composition on days -1, 6, and 13, and the percent change in lean mass from Day -1 was calculated. PBS = phosphate-buffered saline, Dex = dexamethasone, IgG (20) = control IgG antibody dosed at 20 mg / kg / week, Ab1 (20) = Ab1 antibody dosed at 20 mg / kg / week, and Ab1 (2) = Ab1 antibody dosed at 2 mg / kg / week. Data represent group means ± SEM. Mean percent change data for each group on day 14 (for body weight) and day 13 (for lean mass) were analyzed using a one-way ANOVA, followed by a Dunnett vs. multiple comparisons test. Group 1 (****p<0.0001, ***p<0.0005, **p<0.005, *p<0.05) and vs. Group 5 (++++p<0.0001, +++p<0.0005, ++p<0.005, +p<0.05). ns (not significant).

[0077] FIGURES 12A-12D are graphs showing the results of a trial evaluating the weights of different muscles. FIGURE 12A shows the average weight of the gastrocnemius (grams), FIGURE 12B shows the average weight of the quadriceps (grams), FIGURE 12C shows the average percent change in gastrocnemius weight versus control animals treated with PBS (IP) and normal drinking water (Group 1), and FIGURE 12D shows the average percent change in quadriceps weight versus control animals treated with PBS (IP) and normal drinking water (Group 1). PBS = phosphate-buffered saline solution, Dex = dexamethasone, IgG (20) = control IgG antibody dosed at 20 mg / kg / week, Ab1 (20) = Ab1 antibody dosed at 20 mg / kg / week, and Ab1 (2) = Ab1 antibody dosed at 2 mg / kg / week. For FIGURES 12A Petition 870210013044, dated 08 / 02 / 2021, page 34 / 205 24 / 190 percent change in weight from Day 0 calculated from animals weighed twice weekly throughout the study. (FIGURE 11B) Animals underwent EchoMRI (QMRN) to measure body composition on days -1, 6, and 13, and the percent change in lean mass from Day -1 was calculated. PBS = phosphate-buffered saline, Dex = dexamethasone, IgG (20) = control IgG antibody dosed at 20 mg / kg / week, Ab1 (20) = Ab1 antibody dosed at 20 mg / kg / week, and Ab1 (2) = Ab1 antibody dosed at 2 mg / kg / week. Data represent group means ± SEM. Mean percent change data for each group on day 14 (for body weight) and day 13 (for lean mass) were analyzed using a one-way ANOVA, followed by a Dunnett vs. multiple comparisons test. Group 1 (****p<0.0001, ***p<0.0005, **p<0.005, *p<0.05) and vs. Group 5 (++++p<0.0001, +++p<0.0005, ++p<0.005, +p<0.05). ns (not significant).

[0077] FIGURES 12A-12D are graphs showing the results of a trial evaluating the weights of different muscles. FIGURE 12A shows the average weight of the gastrocnemius (grams), FIGURE 12B shows the average weight of the quadriceps (grams), FIGURE 12C shows the average percent change in gastrocnemius weight versus control animals treated with PBS (IP) and normal drinking water (Group 1), and FIGURE 12D shows the average percent change in quadriceps weight versus control animals treated with PBS (IP) and normal drinking water (Group 1). PBS = phosphate-buffered saline solution, Dex = dexamethasone, IgG (20) = control IgG antibody dosed at 20 mg / kg / week, Ab1 (20) = Ab1 antibody dosed at 20 mg / kg / week, and Ab1 (2) = Ab1 antibody dosed at 2 mg / kg / week. For FIGURES 12APetition 870210013044, dated 08 / 02 / 2021, page 34 / 205 25 / 190 In Figure 12B, error bars represent standard deviation (SD). For Figures 12C-12D, error bars represent standard error of the mean (SEM). Statistical evaluation was performed using a one-way ANOVA, followed by a Dunnett multiple comparisons test vs. group 1 (****p<0.0001, ***p<0.0005, **p<0.005, *p<0.05) and vs. group 5 (++++p<0.0001, +++p<0.0005, ++p<0.005, +p<0.05). ns (not significant). Bars indicate, from left to right, PBS, water; PBS, dex; IgG control; Ab1 (20); and Ab1 (2).

[0078] FIGURES 13A-13B show the results of a trial evaluating mean percent body weight and change in lean mass. FIGURE 13A shows the percent change in weight from Day 0 calculated for animals that were weighed twice weekly throughout the study. A FIGURE 13B shows the percentage change in lean mass of Day -1 calculated from animals that underwent EchoMRI (QRMN) to measure body composition on days -1, 7, and 14. PBS = phosphate-buffered saline, IgG (20) = antibody IgG control measured at 20 mg / kg / week, Ab1 (20) = antibody Ab1 measured at 20 mg / kg / week and Ab1 (2) = antibody Ab1 dosed at 2 mg / kg / week. Data represent group means ± SEM.

[0079] FIGURES 14A-14D show the results of a trial evaluating muscle weights. FIGURE 14A shows the average weight of the gastrocnemius muscle in the casted leg (grams), FIGURE 14B shows the average weight of the quadriceps muscle in the casted leg (grams), FIGURE 14C shows the average percentage change in gastrocnemius weight versus control animals treated with PBS (IP) and not casted (Group 1), and FIGURE 14D shows the average percentage change in Petition 870210013044, dated 08 / 02 / 2021, page 35 / 205 25 / 190 In Figure 12B, error bars represent standard deviation (SD). For Figures 12C-12D, error bars represent standard error of the mean (SEM). Statistical evaluation was performed using a one-way ANOVA, followed by a Dunnett multiple comparisons test vs. group 1 (****p<0.0001, ***p<0.0005, **p<0.005, *p<0.05) and vs. group 5 (++++p<0.0001, +++p<0.0005, ++p<0.005, +p<0.05). ns (not significant). Bars indicate, from left to right, PBS, water; PBS, dex; IgG control; Ab1 (20); and Ab1 (2).

[0078] FIGURES 13A-13B show the results of a trial evaluating mean percent body weight and change in lean mass. FIGURE 13A shows the percent change in weight from Day 0 calculated for animals that were weighed twice weekly throughout the study. A FIGURE 13B shows the percentage change in lean mass of Day -1 calculated from animals that underwent EchoMRI (QRMN) to measure body composition on days -1, 7, and 14. PBS = phosphate-buffered saline, IgG (20) = antibody IgG control measured at 20 mg / kg / week, Ab1 (20) = antibody Ab1 measured at 20 mg / kg / week and Ab1 (2) = antibody Ab1 dosed at 2 mg / kg / week. Data represent group means ± SEM.

[0079] FIGURES 14A-14D show the results of a trial evaluating muscle weights. FIGURE 14A shows the average weight of the gastrocnemius muscle in the casted leg (grams), FIGURE 14B shows the average weight of the quadriceps muscle in the casted leg (grams), FIGURE 14C shows the average percentage change in gastrocnemius weight versus control animals treated with PBS (IP) and not casted (Group 1), and FIGURE 14D shows the average percentage change in Petition 870210013044, dated 08 / 02 / 2021, page 35 / 205 26 / 190 quadriceps weight versus control animals treated with PBS (IP) and not immobilized (Group 1). PBS = phosphate-buffered saline solution, IgG (20) = control IgG antibody dosed at 20 mg / kg / week, Ab1 (20) = Ab1 antibody dosed at 20 mg / kg / week, and Ab1 (2) = Ab1 antibody dosed at 2 mg / kg / week. For FIGURES 14A-14B, error bars represent standard deviation (SD). For FIGURES 14C-14D, error bars represent standard error of the mean (SEM). Statistical evaluation was performed using a one-way ANOVA, followed by a Dunnett multiple comparisons test vs. group 1 (****p<0.0001, ***p<0.0005, **p<0.005, *p<0.05) and vs. group 5 (++++p<0.0001, +++p<0.0005, ++p<0.005, +p<0.05). ns (not significant). Bars indicate, from left to right, PBS, without plaster; PBS, plastered; IgG Control (2), plastered; Ab1 (20), plastered; and Ab1 (2), plastered.

[0080] FIGURE 15 shows the results of a trial evaluating the change in lean mass on Day 21 (upper right) and Day 28 (upper left). It also depicts the percentage change in lean mass at three different doses, 20 mg / kg / week (lower left), 2 mg / kg / week (lower middle), and 0.5 mg / kg / week (lower right) of the tested antibodies, PBS control, and IgG control. Statistical analysis was performed using a one-way ANOVA, followed by a Dunnett multiple comparisons test vs. group 1 (****p<0.0001, ***p<0.005, **p<0.01, *p<0.05) and vs. the IgG control. For the two upper panels, the bars from left to right are: PBS; IgG control 20 mg / kg / week; Ab1 20 mg / kg / week; Ab1 2 mg / kg / week; Ab1 0.5 mg / kg / week; Ab2 20 mg / kg / week; Ab2 Petition 870210013044, dated 08 / 02 / 2021, page 36 / 205 26 / 190 quadriceps weight versus control animals treated with PBS (IP) and not immobilized (Group 1). PBS = phosphate-buffered saline solution, IgG (20) = control IgG antibody dosed at 20 mg / kg / week, Ab1 (20) = Ab1 antibody dosed at 20 mg / kg / week, and Ab1 (2) = Ab1 antibody dosed at 2 mg / kg / week. For FIGURES 14A-14B, error bars represent standard deviation (SD). For FIGURES 14C-14D, error bars represent standard error of the mean (SEM). Statistical evaluation was performed using a one-way ANOVA, followed by a Dunnett multiple comparisons test vs. group 1 (****p<0.0001, ***p<0.0005, **p<0.005, *p<0.05) and vs. group 5 (++++p<0.0001, +++p<0.0005, ++p<0.005, +p<0.05). ns (not significant). Bars indicate, from left to right, PBS, without plaster; PBS, plastered; IgG Control (2), plastered; Ab1 (20), plastered; and Ab1 (2), plastered.

[0080] FIGURE 15 shows the results of a trial evaluating the change in lean mass on Day 21 (upper right) and Day 28 (upper left). It also depicts the percentage change in lean mass at three different doses, 20 mg / kg / week (lower left), 2 mg / kg / week (lower middle), and 0.5 mg / kg / week (lower right) of the tested antibodies, PBS control, and IgG control. Statistical analysis was performed using a one-way ANOVA, followed by a Dunnett multiple comparisons test vs. group 1 (****p<0.0001, ***p<0.005, **p<0.01, *p<0.05) and vs. the IgG control. For the two upper panels, the bars from left to right are: PBS; IgG control 20 mg / kg / week; Ab1 20 mg / kg / week; Ab1 2 mg / kg / week; Ab1 0.5 mg / kg / week; Ab2 20 mg / kg / week; Ab2 Petition 870210013044, dated 08 / 02 / 2021, page 36 / 205 27 / 190 mg / kg / week; Ab2 0.5 mg / kg / week; Ab4 20 mg / kg / week; Ab4 2 mg / kg / week; Ab4 0.5 mg / kg / week; Ab6 20 mg / kg / week; Ab6 2 mg / kg / week; and Ab6 0.5 mg / kg / week. For the lower left panel (20 mg / kg / week), the data points corresponding to day 28 post-dose, from top to bottom, correspond to Ab1, Ab4, Ab2, Ab6, IgG control, and PBS. For the lower center panel (2 mg / kg / week), the data points corresponding to day 28 post-dose, from top to bottom, correspond to Ab2, Ab1, Ab6, Ab4, IgG control, and PBS. For the lower right panel (0.5 mg / kg / week), the data points, corresponding to day 28 post-dosing, from top to bottom, correspond to the IgG Ab1, Ab2, PBS, Ab4, and Ab6 controls.

[0081] FIGURES 16A-16B show the domain structure and evaluation of myostatin precursor forms. FIGURE 16A shows the domain structure of promyostatin and latent myostatin, with protease cleavage sites indicated. FIGURE 16B shows promyostatin partially cleaved by proprotein convertase processed on an SDS PAGE gel. Under reducing conditions, the protein bands consisted of promyostatin monomer (approximately 50 kD), prodomain (approximately 37 kD), and growth factor (12.5 kD).

[0082] FIGURES 17A-17B show that Ab1 is specific for myostatin. FIGURE 17A shows that Ab1 binds specifically to promyostatin and latent myostatin, with no binding observed to other members of the TGFB superfamily, most notably to the corresponding GDF11 forms. Ab1 was administered at a high concentration (50 μg / ml) to Forte-Bio BLI tips coated with the indicated antigen. Petition 870210013044, dated 08 / 02 / 2021, page 37 / 205 27 / 190 mg / kg / week; Ab2 0.5 mg / kg / week; Ab4 20 mg / kg / week; Ab4 2 mg / kg / week; Ab4 0.5 mg / kg / week; Ab6 20 mg / kg / week; Ab6 2 mg / kg / week; and Ab6 0.5 mg / kg / week. For the lower left panel (20 mg / kg / week), the data points corresponding to day 28 post-dose, from top to bottom, correspond to Ab1, Ab4, Ab2, Ab6, IgG control, and PBS. For the lower center panel (2 mg / kg / week), the data points corresponding to day 28 post-dose, from top to bottom, correspond to Ab2, Ab1, Ab6, Ab4, IgG control, and PBS. For the lower right panel (0.5 mg / kg / week), the data points, corresponding to day 28 post-dosing, from top to bottom, correspond to the IgG Ab1, Ab2, PBS, Ab4, and Ab6 controls.

[0081] FIGURES 16A-16B show the domain structure and evaluation of myostatin precursor forms. FIGURE 16A shows the domain structure of promyostatin and latent myostatin, with protease cleavage sites indicated. FIGURE 16B shows promyostatin partially cleaved by proprotein convertase processed on an SDS PAGE gel. Under reducing conditions, the protein bands consisted of promyostatin monomer (approximately 50 kD), prodomain (approximately 37 kD), and growth factor (12.5 kD).

[0082] FIGURES 17A-17B show that Ab1 is specific for myostatin. FIGURE 17A shows that Ab1 binds specifically to promyostatin and latent myostatin, with no binding observed to other members of the TGFB superfamily, most notably to the corresponding GDF11 forms. Ab1 was administered at a high concentration (50 μg / ml) to Forte-Bio BLI tips coated with the indicated antigen. Petition 870210013044, dated 08 / 02 / 2021, page 37 / 205 28 / 190 and the on and off rates were measured to obtain an approximate Kd value. The magnitude of the biosensor response, indicating a binding event, is graphically represented by black bars, and the calculated Kd is indicated in orange. FIGURE 17B shows that Ab1 blocks promyostatin activation but not pro-GDF11. After an overnight proteolysis reaction with enzymes from both the proprotein convertase and toloid protease families, mature growth factor release was measured using a CAGA-based reporter assay in 293T cells. The results were compared with control reactions to calculate the fraction of promyostatin or pro-GDF11 that was released in the assay.

[0083] FIGURES 18A-18C show the dose-response of SCID with the candidate antibodies. FIGURE 18A shows the muscle weight of the gastrocnemius and FIGURE 18B shows the muscle weight of the quadriceps. FIGURE 18C shows the percentage changes in mean muscle weight compared to the PBS control. The bars in FIGURES 18A-18B, from left to right, are: PBS; IgG control 20 mg / kg / week; Ab1 20 mg / kg / week; Ab1 2 mg / kg / week; Ab1 0.5 mg / kg / week; Ab2 20 mg / kg / week; Ab2 2 mg / kg / week; Ab2 0.5 mg / kg / week; Ab4 20 mg / kg / week; Ab4 2 mg / kg / week; Ab4 0.5 mg / kg / week; Ab6 20 mg / kg / week; Ab6 2 mg / kg / week; and Ab6 0.5 mg / kg / week.

[0084] FIGURE 19 shows the results of a duration-of-action study comparing Ab1 with an existing myostatin antibody (AbMyo). PBS was used as a negative control; IgG was used as a positive control. The change in lean mass was examined under different dosing protocols after 21 days. Petition 870210013044, dated 08 / 02 / 2021, page 38 / 205 28 / 190 and the on and off rates were measured to obtain an approximate Kd value. The magnitude of the biosensor response, indicating a binding event, is graphically represented by black bars, and the calculated Kd is indicated in orange. FIGURE 17B shows that Ab1 blocks promyostatin activation but not pro-GDF11. After an overnight proteolysis reaction with enzymes from both the proprotein convertase and toloid protease families, mature growth factor release was measured using a CAGA-based reporter assay in 293T cells. The results were compared with control reactions to calculate the fraction of promyostatin or pro-GDF11 that was released in the assay.

[0083] FIGURES 18A-18C show the dose-response of SCID with the candidate antibodies. FIGURE 18A shows the muscle weight of the gastrocnemius and FIGURE 18B shows the muscle weight of the quadriceps. FIGURE 18C shows the percentage changes in mean muscle weight compared to the PBS control. The bars in FIGURES 18A-18B, from left to right, are: PBS; IgG control 20 mg / kg / week; Ab1 20 mg / kg / week; Ab1 2 mg / kg / week; Ab1 0.5 mg / kg / week; Ab2 20 mg / kg / week; Ab2 2 mg / kg / week; Ab2 0.5 mg / kg / week; Ab4 20 mg / kg / week; Ab4 2 mg / kg / week; Ab4 0.5 mg / kg / week; Ab6 20 mg / kg / week; Ab6 2 mg / kg / week; and Ab6 0.5 mg / kg / week.

[0084] FIGURE 19 shows the results of a duration-of-action study comparing Ab1 with an existing myostatin antibody (AbMyo). PBS was used as a negative control; IgG was used as a positive control. The change in lean mass was examined under different dosing protocols after 21 days. Petition 870210013044, dated 08 / 02 / 2021, p. 38 / 205 29 / 190

[0085] FIGURE 20 is a schematic representation illustrating an assay that reconstructs myostatin activation in vitro.

[0086] FIGURES 21A-21B show the heavy chain (FIGURE 21A; SEQ. ID. NO: 50) and light chain (FIGURE 21B; SEQ. ID. NO: 51) of a humanized monoclonal antibody (Ab2) of the IgG4 subtype with Proline replacing Serine. This generates a hinge sequence similar to IgG1 and minimizes the incomplete formation of interchain disulfide bridges that are characteristic of IgG4. Complementarity-determining regions (CDRs) are underlined. NST sequence in bold: N-linked glycosylation consensus sequence site; DP sequences in bold are potential cleavage sites; NX sequences in bold, where X can be S, T, or G, are potential deamidation sites; DX sequences in bold, where X can be G, S, T, or SDG, are potential isomerization sites; Methionines in bold are potential methionine oxidation sites; Q in bold is the expected N-terminal pyroglutamic acid.

[0087] FIGURE 22 is a schematic representation showing the reduced immunogenicity risk by germline definition. 24H4 (WT) contains 5 non-germline amino acids within scaffold regions, as indicated in the schematic representation.

[0088] FIGURES 23A-23C show the optimization of Ab1. Optimized candidates that specifically bind to promiostatin were selected, resulting in dozens of clones with increased affinity. FACS was performed to show the increased binding of the yeast clones (FIGURE 23B) compared to Ab1 (FIGURE 23A). FIGURE 23C shows that the Petition 870210013044, dated 08 / 02 / 2021, page 39 / 205 29 / 190

[0085] FIGURE 20 is a schematic representation illustrating an assay that reconstructs myostatin activation in vitro.

[0086] FIGURES 21A-21B show the heavy chain (FIGURE 21A; SEQ. ID. NO: 50) and light chain (FIGURE 21B; SEQ. ID. NO: 51) of a humanized monoclonal antibody (Ab2) of the IgG4 subtype with Proline replacing Serine. This generates a hinge sequence similar to IgG1 and minimizes the incomplete formation of interchain disulfide bridges that are characteristic of IgG4. Complementarity-determining regions (CDRs) are underlined. NST sequence in bold: N-linked glycosylation consensus sequence site; DP sequences in bold are potential cleavage sites; NX sequences in bold, where X can be S, T, or G, are potential deamidation sites; DX sequences in bold, where X can be G, S, T, or SDG, are potential isomerization sites; Methionines in bold are potential methionine oxidation sites; Q in bold is the expected N-terminal pyroglutamic acid.

[0087] FIGURE 22 is a schematic representation showing the reduced immunogenicity risk by germline definition. 24H4 (WT) contains 5 non-germline amino acids within scaffold regions, as indicated in the schematic representation.

[0088] FIGURES 23A-23C show the optimization of Ab1. Optimized candidates that specifically bind to promiostatin were selected, resulting in dozens of clones with increased affinity. FACS was performed to show the increased binding of the yeast clones (FIGURE 23B) compared to Ab1 (FIGURE 23A). FIGURE 23C shows that the Petition 870210013044, dated 08 / 02 / 2021, page 39 / 205 30 / 190 variants with matured affinity also have a slower offrate per octet.

[0089] FIGURES 24A-24B show sequence alignments of the variable heavy regions (FIGURE 24A) and variable light regions (FIGURE 24B) of parental Ab1 with affinity-optimized variants, Ab3 and Ab5. The sequence identifiers, from top to bottom, correspond to the SEQ. IDs Nos.: 24, 26, 28 (FIGURE 24A). The sequence identifiers, from top to bottom, correspond to the sequence IDs: 30, 32, 34 (FIGURE 24B). Complementary determining regions (CDRs) are defined using Kabat nomenclature (underlined) and IMGT nomenclature (in bold). Parental Ab1 replacements are shown in light gray.

[0090] FIGURE 25 shows the expression of promyostatin and latent myostatin in the muscle and plasma of normal and atrophic mice.

[0091] FIGURE 26 shows the quantification of changes in promyostatin and latent myostatin in muscle and plasma. The bars from left to right show promyostatin, latent myostatin, promyostatin, latent myostatin, and latent myostatin.

[0092] FIGURE 27 shows that Ab2 uniquely recognizes promyostatin and latent myostatin, binding to major myostatin forms in both serum and muscle. Non-reducing Western blot for prodomain (darker gray) and mature growth factor (lighter gray). Recombinant promyostatin (rPromyostatin) shows the migration of promyostatin and myostatin prodomain (latent myostatin) in the gel, highlighted by arrows. In serum, Petition 870210013044, dated 08 / 02 / 2021, page 40 / 205 30 / 190 variants with matured affinity also have a slower offrate per octet.

[0089] FIGURES 24A-24B show sequence alignments of the variable heavy regions (FIGURE 24A) and variable light regions (FIGURE 24B) of parental Ab1 with affinity-optimized variants, Ab3 and Ab5. The sequence identifiers, from top to bottom, correspond to the SEQ. IDs Nos.: 24, 26, 28 (FIGURE 24A). The sequence identifiers, from top to bottom, correspond to the sequence IDs: 30, 32, 34 (FIGURE 24B). Complementary determining regions (CDRs) are defined using Kabat nomenclature (underlined) and IMGT nomenclature (in bold). Parental Ab1 replacements are shown in light gray.

[0090] FIGURE 25 shows the expression of promyostatin and latent myostatin in the muscle and plasma of normal and atrophic mice.

[0091] FIGURE 26 shows the quantification of changes in promyostatin and latent myostatin in muscle and plasma. The bars from left to right show promyostatin, latent myostatin, promyostatin, latent myostatin, and latent myostatin.

[0092] FIGURE 27 shows that Ab2 uniquely recognizes promyostatin and latent myostatin, binding to major myostatin forms in both serum and muscle. Non-reducing Western blot for prodomain (darker gray) and mature growth factor (lighter gray). Recombinant promyostatin (rPromyostatin) shows the migration of promyostatin and myostatin prodomain (latent myostatin) in the gel, highlighted by arrows. In serum, Petition 870210013044, dated 08 / 02 / 2021, page 40 / 205 31 / 190 Both Ab2 and AbMyo bind to latent myostatin (pro-domain band) and several partially processed precursors; however, only Ab2 recognized promyostatin (upper band). In muscle, Ab2 precipitated promyostatin, with no interaction of AbMyo with promyostatin in muscle tissue.

[0093] FIGURES 28A-28B provide a model for myostatin flux in normal and atrophic muscle. In normal muscle (FIGURE 28A), promyostatin is produced in the muscle and converted to latent myostatin via furin protease cleavage, which can occur inside or outside the cell. Some fraction of the latent myostatin in the muscle is then released into the circulation, forming a circulating pool of latent myostatin. In muscle atrophy (FIGURE 28B), an increase in active myostatin growth factor is caused by upregulation of promyostatin levels in the muscle and increased conversion of latent myostatin to active growth factor. As a consequence, circulating latent myostatin is decreased as the muscle pool of latent myostatin is redirected toward the formation of mature myostatin by mTLL2 cleavage.

[0094] FIGURE 29 shows the detection of Ab2 antibody (top line) and IgG control (bottom line) in the serum of dosed rats. Ab2 exhibits elevated levels in circulation, compared to the IgG control, with an average of 17.1 pg / ml of Ab2 in serum at the end of the study. Ab2 levels were determined by human IgG-specific ELISA with known quantities of each antibody used as a reference standard.

[0095] FIGURES 30A-30B show effects Petition 870210013044, dated 08 / 02 / 2021, page 41 / 205 31 / 190 Both Ab2 and AbMyo bind to latent myostatin (pro-domain band) and several partially processed precursors; however, only Ab2 recognized promyostatin (upper band). In muscle, Ab2 precipitated promyostatin, with no interaction of AbMyo with promyostatin in muscle tissue.

[0093] FIGURES 28A-28B provide a model for myostatin flux in normal and atrophic muscle. In normal muscle (FIGURE 28A), promyostatin is produced in the muscle and converted to latent myostatin via furin protease cleavage, which can occur inside or outside the cell. Some fraction of the latent myostatin in the muscle is then released into the circulation, forming a circulating pool of latent myostatin. In muscle atrophy (FIGURE 28B), an increase in active myostatin growth factor is caused by upregulation of promyostatin levels in the muscle and increased conversion of latent myostatin to active growth factor. As a consequence, circulating latent myostatin is decreased as the muscle pool of latent myostatin is redirected toward the formation of mature myostatin by mTLL2 cleavage.

[0094] FIGURE 29 shows the detection of Ab2 antibody (top line) and IgG control (bottom line) in the serum of dosed rats. Ab2 exhibits elevated levels in circulation, compared to the IgG control, with an average of 17.1 pg / ml of Ab2 in serum at the end of the study. Ab2 levels were determined by human IgG-specific ELISA with known quantities of each antibody used as a reference standard.

[0095] FIGURES 30A-30B show effects Petition 870210013044, dated 08 / 02 / 2021, page 41 / 205 32 / 190 pharmacodynamic effects of Ab2 in treated rats. FIGURE 30A shows that rats treated with Ab2 exhibit increased lean mass compared to animals treated with PBS or treated with IgG control. Ab2 and IgG were administered intravenously at doses of 10 mg / kg on day 0. Lean mass was measured by qNMR (N = 8 per group) at 7, 14, 21, and 28 days post-dosing. FIGURE 30B shows that rectus femoris and tibialis anterior muscles were harvested from all groups at the end of the study (N = 8 per group) and weighed to determine muscle mass. Rats treated with Ab2 exhibited a 14% and 11% increase in rectus femoris and tibialis anterior muscle masses, respectively.

[0096] FIGURES 31A-31B show the levels of promyostatin / latent myostatin in rats treated with Ab2. FIGURE 31A shows that treatment with Ab2 (top row) increases latent myostatin levels in rat serum by approximately 20 times. FIGURE 31B shows that, in rat muscle (rectus femoris), treatment with Ab2 leads to a 1.9x increase in the latent form of myostatin. The bars, from left to right, correspond to promyostatin, latent myostatin, promyostatin, and latent myostatin. No statistically significant change in promyostatin is observed in rat muscle. These data are from quantitative western analyses with n=3 samples per group.

[0097] FIGURE 32 shows that treatment with Ab2 (Ab2) or with the comparator antibody (AbMyo) leads to increased lean mass as early as 7 days after antibody dosing. Increases in lean mass are equivalent for Ab2 and AbMyo up to 21 days after dosing. By approximately 28 days after dosing, however, the increases in lean mass are lost. Petition 870210013044, dated 08 / 02 / 2021, page 42 / 205 32 / 190 pharmacodynamic effects of Ab2 in treated rats. FIGURE 30A shows that rats treated with Ab2 exhibit increased lean mass compared to animals treated with PBS or treated with IgG control. Ab2 and IgG were administered intravenously at doses of 10 mg / kg on day 0. Lean mass was measured by qNMR (N = 8 per group) at 7, 14, 21, and 28 days post-dosing. FIGURE 30B shows that rectus femoris and tibialis anterior muscles were harvested from all groups at the end of the study (N = 8 per group) and weighed to determine muscle mass. Rats treated with Ab2 exhibited a 14% and 11% increase in rectus femoris and tibialis anterior muscle masses, respectively.

[0096] FIGURES 31A-31B show the levels of promyostatin / latent myostatin in rats treated with Ab2. FIGURE 31A shows that treatment with Ab2 (top row) increases latent myostatin levels in rat serum by approximately 20 times. FIGURE 31B shows that, in rat muscle (rectus femoris), treatment with Ab2 leads to a 1.9x increase in the latent form of myostatin. The bars, from left to right, correspond to promyostatin, latent myostatin, promyostatin, and latent myostatin. No statistically significant change in promyostatin is observed in rat muscle. These data are from quantitative western analyses with n=3 samples per group.

[0097] FIGURE 32 shows that treatment with Ab2 (Ab2) or with the comparator antibody (AbMyo) leads to increased lean mass as early as 7 days after antibody dosing. Increases in lean mass are equivalent for Ab2 and AbMyo up to 21 days after dosing. By approximately 28 days after dosing, however, the increases in lean mass are lost. Petition 870210013044, dated 08 / 02 / 2021, page 42 / 205 33 / 190 in the AbMyo-treated group, while increases in the Ab2-treated group are maintained throughout the study. The top line corresponds to Ab2, the middle line corresponds to AbMyo, and the bottom line corresponds to the IgG Control (5 mg / kg).

[0098] FIGURE 33 shows that after a single dose of 5 mg / kg of Ab2 (top line) or comparator antibody (AbMyo; bottom line), serum drug levels were measured using an anti-human IgG ELISA. Drug is detected in serum as early as 1 hour after dosing, and levels > 1 pg / ml of both antibodies can be detected throughout the study. However, Ab2 exhibits a significantly longer half-life and inferred area under the curve (AUCINF) than AbMyo, suggesting that, at similar doses, Ab2 exhibits significantly greater exposure than AbMyo.

[0099] FIGURE 34 shows that serum myostatin was measured in drug-treated mice and controls using fluorescent Western blotting. Despite increased serum exposure to Ab2, serum levels of latent myostatin in mice treated with both Ab2 and AbMyo were similar. These data suggest that circulating levels of free drug are sufficiently in excess of the target level that increased serum exposure to Ab2 does not lead to a greater increase in circulating latent myostatin than is observed in the AbMyo group. Data groups, from left to right, correspond to IgG, Ab2, AbMyo, IgG, Ab2, and AbMyo.

[00100] FIGURES 35A-35B show that the relative levels of latent myostatin and promyostatin were measured in mouse muscle lysates by Western blot. Petition 870210013044, dated 08 / 02 / 2021, p. 43 / 205 33 / 190 in the AbMyo-treated group, while increases in the Ab2-treated group are maintained throughout the study. The top line corresponds to Ab2, the middle line corresponds to AbMyo, and the bottom line corresponds to the IgG Control (5 mg / kg).

[0098] FIGURE 33 shows that after a single dose of 5 mg / kg of Ab2 (top line) or comparator antibody (AbMyo; bottom line), serum drug levels were measured using an anti-human IgG ELISA. Drug is detected in serum as early as 1 hour after dosing, and levels > 1 pg / ml of both antibodies can be detected throughout the study. However, Ab2 exhibits a significantly longer half-life and inferred area under the curve (AUCINF) than AbMyo, suggesting that, at similar doses, Ab2 exhibits significantly greater exposure than AbMyo.

[0099] FIGURE 34 shows that serum myostatin was measured in drug-treated mice and controls using fluorescent Western blotting. Despite increased serum exposure to Ab2, serum levels of latent myostatin in mice treated with both Ab2 and AbMyo were similar. These data suggest that circulating levels of free drug are sufficiently in excess of the target level that increased serum exposure to Ab2 does not lead to a greater increase in circulating latent myostatin than is observed in the AbMyo group. Data groups, from left to right, correspond to IgG, Ab2, AbMyo, IgG, Ab2, and AbMyo.

[00100] FIGURES 35A-35B show that the relative levels of latent myostatin and promyostatin were measured in mouse muscle lysates by Western blot. Petition 870210013044, dated 08 / 02 / 2021, p. 43 / 205 34 / 190 fluorescent. FIGURE 35A shows that latent myostatin is elevated in muscles treated with both Ab2 and AbMyo. However, the elevation of latent myostatin in muscles treated with AbMyo returns to baseline levels around day 28, while those in muscles treated with Ab2 remain elevated until at least that time (P<0.003 vs. AbMyo treatment). FIGURE 35B shows that a similar trend is observed with promyostatin, although the difference between the Ab2 and AbMyo treated groups on day 28 is not statistically significant (P=0.068).

[00101] FIGURE 36A shows the effects of Ab2 treatment on muscle mass and function in mice.

[00102] FIGURE 36B shows the effects of Ab2 treatment on maximum force generation in mice. DETAILED DESCRIPTION

[00103] Myostatin is a member of the TGFP superfamily, and belongs to a subfamily that includes two members: myostatin (also known as GDF8) and GDF11. Like other members of the TGFp superfamily, myostatin and GDF11 are both initially expressed as inactive precursor polypeptides (called promyostatin and proGDF11, respectively). The domain structure and nomenclature are shown in FIGURE 1A. FIGURE 1B illustrates a drawn model of the overall structure of promyostatin, in which the mature growth factor is held trapped in a cage composed of two alpha helices connected by a loop called the “lag loop.”

[00104] The activation and release of mature growth factor are achieved by several distinct protease cleavage events, described in FIGURE 2. The first step of Petition 870210013044, dated 08 / 02 / 2021, page 44 / 205 34 / 190 fluorescent. FIGURE 35A shows that latent myostatin is elevated in muscles treated with both Ab2 and AbMyo. However, the elevation of latent myostatin in muscles treated with AbMyo returns to baseline levels around day 28, while those in muscles treated with Ab2 remain elevated until at least that time (P<0.003 vs. AbMyo treatment). FIGURE 35B shows that a similar trend is observed with promyostatin, although the difference between the Ab2 and AbMyo treated groups on day 28 is not statistically significant (P=0.068).

[00101] FIGURE 36A shows the effects of Ab2 treatment on muscle mass and function in mice.

[00102] FIGURE 36B shows the effects of Ab2 treatment on maximum force generation in mice. DETAILED DESCRIPTION

[00103] Myostatin is a member of the TGFP superfamily, and belongs to a subfamily that includes two members: myostatin (also known as GDF8) and GDF11. Like other members of the TGFp superfamily, myostatin and GDF11 are both initially expressed as inactive precursor polypeptides (referred to as pro-myostatin and pro-GDF11, respectively). The domain structure and nomenclature are shown in FIGURE 1A. FIGURE 1B illustrates a drawn model of the overall structure of pro-myostatin, in which the mature growth factor is held within a cage composed of two alpha helices connected by a loop called the “lag loop.”

[00104] The activation and release of mature growth factor are achieved by several distinct protease cleavage events, described in FIGURE 2. The first step of Petition 870210013044, dated 08 / 02 / 2021, page 44 / 205 35 / 190 Cleavage of promyostatin and proGDF11 is performed by a proprotein convertase, which cleaves at a conserved RXXR site between the prodomain and mature growth factor. This cleavage produces a latent complex, in which the mature growth factor is shielded from binding to its receptors by the prodomain. Activation and release of the active mature myostatin growth factor are achieved after cleavage by an additional BMP / toloid family protease, for example, mTLL-2 (FIGURE 2).

[00105] Exemplary pro-GDF8 sequences in humans, rats, mice, and Cynomolgus are provided below. In these pro-GDF8 sequences, a proprotein convertase cleavage site is indicated in bold and a toloid protease site is indicated by underlining. In some embodiments, the proprotein convertase cleavage site comprises amino acid residues 240 to 243 of IDS. SEQ. Nos: 52-55. In some embodiments, the toloid protease site comprises amino acid residues 74-75 of IDS. SEQ. Nos: 52-55. It should be noted that the exemplary pro-GDF8 sequences provided in this descriptive report are not intended to be limiting, and additional pro-GDF8 sequences from other species, including any isoforms thereof, are within the scope of this disclosure.

[00106] pro-GDF8 (human): NENSEQKENVEKEGLCNACTWRQNTKSSRIEAIKIQILSKLRLETAPNISKDVIRQLLP KAPPLRELIDQYDVQRDDSSDGSLEDDDYHATTETIITMPTESDFLMQVDGKPKCCFFK FSSKIQYNKVVKAQLWIYLRPVETPTTVFVQIRLLIKPMKDGTRYTGIRSLKLDMNPGT GIWQSIDVKTVLQNWLKQPESNLGIEIKALDENGHDLAVTFPGPGEDGLNPFLEVKVTD TPKRSRRDFGLDCDEHSTESRCCRYPLTVDFEAFGWDWIIAPKRYKANYCSGECEFVFL QKYPHTHLVHQANPRGSAGPCCTPTKMSPINMLYFNGKEQIIYGKIPAMVVDRCGCS Petition 870210013044, dated 08 / 02 / 2021, page 45 / 205 35 / 190 Cleavage of promyostatin and proGDF11 is performed by a proprotein convertase, which cleaves at a conserved RXXR site between the prodomain and mature growth factor. This cleavage produces a latent complex, in which the mature growth factor is shielded from binding to its receptors by the prodomain. Activation and release of the active mature myostatin growth factor are achieved after cleavage by an additional BMP / toloid family protease, for example, mTLL-2 (FIGURE 2).

[00105] Exemplary pro-GDF8 sequences in humans, rats, mice, and Cynomolgus are provided below. In these pro-GDF8 sequences, a proprotein convertase cleavage site is indicated in bold and a toloid protease site is indicated by underlining. In some embodiments, the proprotein convertase cleavage site comprises amino acid residues 240 to 243 of IDS. SEQ. Nos: 52-55. In some embodiments, the toloid protease site comprises amino acid residues 74-75 of IDS. SEQ. Nos: 52-55. It should be noted that the exemplary pro-GDF8 sequences provided in this descriptive report are not intended to be limiting, and additional pro-GDF8 sequences from other species, including any isoforms thereof, are within the scope of this disclosure.

[00106] pro-GDF8 (human): NENSEQKENVEKEGLCNACTWRQNTKSSRIEAIKIQILSKLRLETAPNISKDVIRQLLP KAPPLRELIDQYDVQRDDSSDGSLEDDDYHATTETITITEMPTESDFLMQVDGKPKCCFFK FSSKIQYNKVVKAQLWIYLRPVETTVFVQILRLIKPMKDGTRYTGIRSLCLDMNPGT GIWQSIDVKTVLQNWLKQPESNLGIEICALDENGHDLAVTFPGGEDGLNPFLEVKVTD TPKRSRRDFGLDCDEHSTESRCYPLTVDFECDFECGFYFGCYVGC QKYPHTHLVHQANPRGSAGPCCTPTKMSPINMLYFNGKEQIIYGKIPAMVVDRCGCS Petition 870210013044, of 08 / 02 / 2021, p. 45 / 205 36 / 190 (ID. DE SEQ. N°: 52).

[00107] pro-GDF8 (mouse) : NEDSEREANVEKEGLCNACAWRQNTRYSRIEAIKIQILSKLRLETAPNISKDAIRQLLP RAPPLRELIDQYDVQRDDSSDGSLEDDDYHATTETITIMPTESDFLMQADGKPKCCFFK FSSKIQYNKVVKAQLWIYLRAVKTPTTVFVQILRLIKTTRYKLDGGLTGTTGTT GIWQSIDVKTVLQNWLKQPESNLGIEICALDENGHDLAVTFPGPGEDGLNPFLEVKVTD TPKRSRRDFGLDCDEHSTESRCCRYPLTVDFEAFGWDWIIAPKRYKANYCSGECEFVFL QKYPHTHLVHQANPRGSAGPCCTPTKMSPINGYFCGYVCG SEQ No: 53).

[00108] pro-GDF8 (camundongo): NEGSEREENVEKEGLCNACAWRQNTRYSRIEAIKIQILSKLRLETAPNISKDAIRQLLP RAPPLRELIDQYDVQRDDSSDGSLEDDDYHATTETIITMPTESDFLMQADGKPKCCFFK FSSKIQYNKVVKAQLWIYLRPVKTPTTVFVQILRLIKPMKDGTRYTGIRSLKLDMSPGT GIWQSIDVKTVLQNWLKQPESNLGIEIKALDENGHDLAVTFPGPGEDGLNPFLEVKVTD TPKRSRRDFGLDCDEHSTESRCCRYPLTVDFEAFGWDWIIAPKRYKANYCSGECEFVFL QKYPHTHLVHQANPRGSAGPCCTPTKMSPINMLYFNGKEQIIYGKIPAMVVDRCGCS (ID. DE SEQ. N°: 54). [0010 9] pró-GDF8 (Cynomolgus): NENSEQKENVEKEGLCNACTWRQNTKSSRIEAIKIQILSKLRLETAPNISKDAIRQLLP KAPPLRELIDQYDVQRDDSSDGSLEDDDYHATTETIITMPTESDFLMQVDGKPKCCFFK FSSKIQYNKVVKAQLWIYLRPVETPTTVFVQILRLIKPMKDGTRYTGIRSLKLDMNPGT GIWQSIDVKTVLQNWLKQPESNLGIEIKALDENGHDLAVTFPGPGEDGLNPFLEVKVTD TPKRSRRDFGLDCDEHSTESRCCRYPLTVDFEAFGWDWIIA (ID. DE SEQ. N°: 55).

[00110] Myostatin and GDF11 share a relatively high degree of conservation between their mature growth factor domains, with ninety percent identity, but are much less conserved in their prodomain regions, with less than fifty percent amino acid identity between the two. Myostatin and GDF11 Petition 870210013044, dated 08 / 02 / 2021, page 46 / 205 36 / 190 (SEQUENCE ID NO.: 52).

[00107] pro-GDF8 (rat) : NEDSEREANVEKEGLCNACAWRQNTRYSRIEAIKIQILSKLRLETAPNISKDAIRQLLP RAPPLRELIDQYDVQRDDSSDGSLEDDDYHATTETIITMPTESDFLMQADGKPKCCFFK FSSKIQYNKVVKAQLWIYLRAVKTPTTVFVQIRLLIKPMKDGTRYTGIRSLKLDMSPGT GIWQSIDVKTVLQNWLKQPESNLGIEIKALDENGHDLAVTFPGPGEDGLNPFLEVKVTD TPKRSRRDFGLDCDEHSTESRCCRYPLTVDFEAFGWDWIIAPKRYKANYCSGECEFVFL QKYPHTHLVHQANPRGSAGPCCTPTKMSPINMLYFNGKEQIIYGKIPAMVVDRCGCS (SEQ ID NO.: 53).

[00108] pro-GDF8 (mouse): NEGSEREENVEKEGLCNACAWRQNTRYSRIEAIKIQILSKLRLETAPNISKDAIRQLLP RAPPLRELIDQYDVQRDDSSDGSLEDDDYHATTETIITMPTESDFLMQADGKPKCCFFK FSSKIQYNKVVKAQLWIYLRPVKTPTTVFVQILRLIKPMKDGTRYTGIRSLKLDMSPGT GIWQSIDVKTVLQNWLKQPESNLGIEIKALDENGHDLAVTFPGPGEDGLNPFLEVKVTD TPKRSRRDFGLDCDEHSTESRCCRYPLTVDFEAFGWDWIIAPKRYKANYCSGECEFVFL QKYPHTHLVHQANPRGSAGPCCTPTKMSPINMLYFNGKEQIIYGKIPAMVVDRCGCS (ID. DE SEQ. N°: 54). [0010 9] pró-GDF8 (Cynomolgus): NENSEQKENVEKEGLCNACTWRQNTKSSRIEAIKIQILSKLRLETAPNISKDAIRQLLP KAPPLRELIDQYDVQRDDSSDGSLEDDDYHATTETIITMPTESDFLMQVDGKPKCCFFK FSSKIQYNKVVKAQLWIYLRPVETPTTVFVQILRLIKPMKDGTRYTGIRSLKLDMNPGT GIWQSIDVKTVLQNWLKQPESNLGIEIKALDENGHDLAVTFPGPGEDGLNPFLEVKVTD TPKRSRRDFGLDCDEHSTESRCCRYPLTVDFEAFGWDWIIA (ID. DE SEQ. N°: 55).

[00110] Myostatin and GDF11 share a relatively high degree of conservation between their mature growth factor domains, with ninety percent identity, but are much less conserved in their prodomain regions, with less than fifty percent amino acid identity between the two. Myostatin and GDF11 Petition 870210013044, dated 08 / 02 / 2021, p. 46 / 205 37 / 190 bind and signal through the same receptors, which consist of a Type I receptor (ALK4 / 5) in association with a Type II receptor (ACTRIIA / B). The engagement of myostatin with Type I and Type II receptors initiates a signaling cascade that leads to SMAD phosphorylation and transcriptional activation of muscle atrophy genes. The relatively high degree of conservation in mature growth factors has made it challenging to identify reagents, for example, monoclonal antibodies, that can differentiate between mature myostatin and GDF11.

[00111] In some embodiments, antibodies to promiostatin / latent myostatin are provided in this descriptive report that bind specifically to a chimeric construct containing the growth factor domain and N-terminal propeptide portion of GDF11 and the C-terminal propeptide portion of GDF8. This chimeric construct, as described below, is termed GDF11Arm8.

[00112] > GDF11Arm8 (SEQ ID. NO: 65) MDMRVPAQLLGLLLLWFSGVLGDYKDDDDKHHHHHHLEVLFQGPAEGPAAAAAAAAAAA AAGVGGERSSRPAPSVAPEPDGCPVCVWRQHSRELRLESIKSQILSKLRLKEAPNISRE VVKQLLPKAPPLRELIDQYDVQRDDSSDGSLEDDDYHATTETIITMPTESDFLMQVDGK PKCCFFKFSSKIQYNKVVKAQLWIYLRPVETPTTVFVQIRLLIKPMKDGTRYTGIRSLK LDMNPGTGIWQSIDVKTVLQNWLKQPESNLGIEIKALDENGHDLAVTFPGPGEDGLNPF LEVKVTDTPKRSRRNLGLDCDEHSSESRCCRYPLTVDFEAFGWDWIIAPKRYKANYCSG QCEYMFMQKYPHTHLVQQANPRGSAGPCCTPTKMSPINMLYFNDKQQIIYGKIPGMVVD RCGCS Role of myostatin in myopathies

[00113] Skeletal muscle accounts for approximately 40% of body mass and is a dynamic organ, Petition 870210013044, dated 08 / 02 / 2021, p. 47 / 205 37 / 190 bind and signal through the same receptors, which consist of a Type I receptor (ALK4 / 5) in association with a Type II receptor (ACTRIIA / B). The engagement of myostatin with Type I and Type II receptors initiates a signaling cascade that leads to SMAD phosphorylation and transcriptional activation of muscle atrophy genes. The relatively high degree of conservation in mature growth factors has made it challenging to identify reagents, for example, monoclonal antibodies, that can differentiate between mature myostatin and GDF11.

[00111] In some embodiments, antibodies to promiostatin / latent myostatin are provided in this descriptive report that bind specifically to a chimeric construct containing the growth factor domain and N-terminal propeptide portion of GDF11 and the C-terminal propeptide portion of GDF8. This chimeric construct, as described below, is termed GDF11Arm8.

[00112] > GDF11Arm8 (SEQ ID. NO: 65) MDMRVPAQLLGLLLLWFSGVLGDYKDDDDKHHHHHHLEVLFQGPAEGPAAAAAAAAAAA AAGVGGERSSRPAPSVAPEPDGCPVCVWRQHSRELRLESIKSQILSKLRLKEAPNISRE VVKQLLPKAPPLRELIDQYDVQRDDSSDGSLEDDDYHATTETIITMPTESDFLMQVDGK PKCCFFKFSSKIQYNKVVKAQLWIYLRPVETPTTVFVQIRLLIKPMKDGTRYTGIRSLK LDMNPGTGIWQSIDVKTVLQNWLKQPESNLGIEIKALDENGHDLAVTFPGPGEDGLNPF LEVKVTDTPKRSRRNLGLDCDEHSSESRCCRYPLTVDFEAFGWDWIIAPKRYKANYCSG QCEYMFMQKYPHTHLVQQANPRGSAGPCCTPTKMSPINMLYFNDKQQIIYGKIPGMVVD RCGCS Role of myostatin in myopathies

[00113] Skeletal muscle accounts for approximately 40% of body mass and is a dynamic organ, Petition 870210013044, dated 08 / 02 / 2021, page 47 / 205 38 / 190, renewing at a rate of 1-2% per day. Muscle atrophy is a highly regulated catabolic process that occurs during periods of disuse (e.g., disuse atrophy) and / or in response to marked systemic inflammation (cachexia). In disuse atrophy, which can occur during prolonged periods of immobilization, such as during bed rest, muscle loss occurs rapidly. For example, during a one-week hospital stay, an average patient loses approximately 1.3 kg of muscle mass.

[00114] Muscle atrophy causes significant morbidity in a wide range of clinical conditions. In denervation diseases such as amyotrophic lateral sclerosis (ALS) or spinal muscular atrophy (SMA), and genetic diseases including muscular dystrophies, the loss of muscle strength and function are highly disabling clinical manifestations for which there are no adequate treatments. In cachexia syndromes resulting from renal failure, AIDS, cardiac conditions, or cancer, muscle loss often compromises the successful treatment of the primary condition. Muscle loss also results from a natural aging process and, in its most severe form, is categorized as sarcopenia, a condition common among the elderly that is increasingly recognized as a pathology requiring intervention. Finally, a major driver of muscle atrophy is disuse.Immobilization causes rapid and significant muscle loss in a wide range of conditions, for example, hip fracture, elective joint replacement, spinal cord injury, intensive care myopathy, and accident. Petition 870210013044, dated 08 / 02 / 2021, page 48 / 205 38 / 190, renewing at a rate of 1-2% per day. Muscle atrophy is a highly regulated catabolic process that occurs during periods of disuse (e.g., disuse atrophy) and / or in response to marked systemic inflammation (cachexia). In disuse atrophy, which can occur during prolonged periods of immobilization, such as during bed rest, muscle loss occurs rapidly. For example, during a one-week hospital stay, an average patient loses approximately 1.3 kg of muscle mass.

[00114] Muscle atrophy causes significant morbidity in a wide range of clinical conditions. In denervation diseases such as amyotrophic lateral sclerosis (ALS) or spinal muscular atrophy (SMA), and genetic diseases including muscular dystrophies, the loss of muscle strength and function are highly disabling clinical manifestations for which there are no adequate treatments. In cachexia syndromes resulting from renal failure, AIDS, cardiac conditions, or cancer, muscle loss often compromises the successful treatment of the primary condition. Muscle loss also results from a natural aging process and, in its most severe form, is categorized as sarcopenia, a condition common among the elderly that is increasingly recognized as a pathology requiring intervention. Finally, a major driver of muscle atrophy is disuse.Immobilization causes rapid and significant muscle loss in a wide range of conditions, for example, hip fracture, elective joint replacement, spinal cord injury, intensive care myopathy, and accident. Petition 870210013044, dated 08 / 02 / 2021, page 48 / 205 39 / 190 cerebrovascular accident. Although varied in their causes, these indications share a characteristic of muscle weakness, which leads to significant disability, lengthy physical rehabilitation and recovery times, and impaired quality of life.

[00115] There is an unmet medical need in conditions of muscle atrophy. Consequently, in some modalities, methods for the treatment of muscle atrophy are provided in this descriptive report. In some modalities, the methods provided in this descriptive report relate to the treatment of a primary myopathy. In some modalities, the methods provided in this descriptive report relate to the treatment of secondary myopathy such as, for example, denervation diseases, genetic muscle weakness, and cachexia, conditions in which muscle loss is secondary to the pathology of the disease. In some modalities, the methods provided in this descriptive report for the treatment of primary myopathies such as, for example, disuse atrophy (e.g., associated with hip fracture or spinal cord injury (SCI)), result in increased muscle mass, strength, and function in an individual. Inhibition of the myostatin pathway

[00116] There are several myostatin pathway antagonists in various stages of clinical development toward the treatment of muscle-related conditions. These pathway antagonists target mature growth factor or its type II receptor, and most antagonize signaling from multiple members of the TGFβ family. For example, several current clinical candidates block factors of Petition 870210013044, dated 08 / 02 / 2021, page 49 / 205 39 / 190 cerebrovascular accident. Although varied in their causes, these indications share a characteristic of muscle weakness, which leads to significant disability, lengthy physical rehabilitation and recovery times, and impaired quality of life.

[00115] There is an unmet medical need in conditions of muscle atrophy. Consequently, in some modalities, methods for the treatment of muscle atrophy are provided in this descriptive report. In some modalities, the methods provided in this descriptive report relate to the treatment of a primary myopathy. In some modalities, the methods provided in this descriptive report relate to the treatment of secondary myopathy such as, for example, denervation diseases, genetic muscle weakness, and cachexia, conditions in which muscle loss is secondary to the pathology of the disease. In some modalities, the methods provided in this descriptive report for the treatment of primary myopathies such as, for example, disuse atrophy (e.g., associated with hip fracture or spinal cord injury (SCI)), result in increased muscle mass, strength, and function in an individual. Inhibition of the myostatin pathway

[00116] There are several myostatin pathway antagonists in various stages of clinical development toward the treatment of muscle-related conditions. These pathway antagonists target mature growth factor or its type II receptor, and most antagonize signaling from multiple members of the TGFβ family. For example, several current clinical candidates block factors of Petition 870210013044, dated 08 / 02 / 2021, page 49 / 205 40 / 190 additional growth factors such as, for example, Activin A, GDF11, and BMPs 9 and 10, which are regulators of reproductive biology, wound healing, erythropoiesis, and blood vessel formation, respectively. Aspects of this revelation are related to the recognition that blocking these factors in addition to myostatin will potentially limit the population of patients who can safely undergo therapy due to unacceptable side effects.

[00117] Consequently, this descriptive report provides antibodies capable of binding to promyostatin and / or latent myostatin, thereby inhibiting myostatin activity, and their uses for the treatment of diseases and disorders associated with myopathy. In some modalities, considering the prevalence of the circulating latent complex, this descriptive report provides treatments that specifically target more abundant and longer-lived myostatin precursors, for example, promyostatin and latent myostatin, instead of mature growth factor. Without adhering to any particular theory, the antibodies provided in this descriptive report may prevent the proteolytic activation of promyostatin and / or latent myostatin into mature myostatin, which is considered the “active” form of myostatin, capable of activating the myostatin pathway, for example, by binding to Type I (ALK4 / 5) and Type II (ACTRIIA / B) receptors.

[00118] As used in this descriptive report, the term “promyostatin / latent myostatin” refers to promyostatin, latent myostatin, or both. In some embodiments, an anti-promyostatin / latent myostatin antibody binds specifically to promyostatin. In some Petition 870210013044, dated 08 / 02 / 2021, page 50 / 205 40 / 190 additional growth factors such as, for example, Activin A, GDF11, and BMPs 9 and 10, which are regulators of reproductive biology, wound healing, erythropoiesis, and blood vessel formation, respectively. Aspects of this revelation are related to the recognition that blocking these factors in addition to myostatin will potentially limit the population of patients who can safely undergo therapy due to unacceptable side effects.

[00117] Consequently, this descriptive report provides antibodies capable of binding to promyostatin and / or latent myostatin, thereby inhibiting myostatin activity, and their uses for the treatment of diseases and disorders associated with myopathy. In some modalities, considering the prevalence of the circulating latent complex, this descriptive report provides treatments that specifically target more abundant and longer-lived myostatin precursors, for example, promyostatin and latent myostatin, instead of mature growth factor. Without adhering to any particular theory, the antibodies provided in this descriptive report may prevent the proteolytic activation of promyostatin and / or latent myostatin into mature myostatin, which is considered the “active” form of myostatin, capable of activating the myostatin pathway, for example, by binding to Type I (ALK4 / 5) and Type II (ACTRIIA / B) receptors.

[00118] As used in this descriptive report, the term “promyostatin / latent myostatin” refers to promyostatin, latent myostatin, or both. In some embodiments, an anti-promyostatin / latent myostatin antibody binds specifically to promyostatin. In some Petition 870210013044, dated 08 / 02 / 2021, page 50 / 205 In 41 / 190 embodiments, an anti-promyostatin / latent myostatin antibody binds specifically to latent myostatin. In some embodiments, an anti-promyostatin / latent myostatin antibody binds specifically to both latent myostatin and promyostatin. It should be noted that “latent myostatin” and “promyostatin” may also be referred to in this descriptive report as “latent GDF8” and “pro-GDF8”, respectively.

[00119] As used in this descriptive report, the term “mature myostatin” refers to a mature, biologically active form of myostatin. In some embodiments, mature myostatin is capable of binding and / or activation of the myostatin receptor. The activation and release of mature myostatin in vivo from its promyostatin form are achieved by several distinct protease cleavage events. To begin, “promyostatin” is cleaved by a proprotein convertase, resulting in “latent myostatin,” in which mature myostatin is shielded from binding to its receptors by a portion of the prodomain. The activation and release of mature myostatin are achieved after cleavage of latent myostatin by an additional BMP / toloid family protease, for example, mTLL-2. See, for example, Figures 1A, 1B, and 2.As used in this descriptive report, the term "mature myostatin" can refer to both full-length mature myostatin and fragments of full-length mature myostatin that retain biological activity. Exemplary mature myostatin sequences, variants thereof, and methods for generating mature myostatin are well known in the art and described in more detail in this descriptive report. Petition 870210013044, dated 08 / 02 / 2021, page 51 / 205 In 41 / 190 embodiments, an anti-promyostatin / latent myostatin antibody binds specifically to latent myostatin. In some embodiments, an anti-promyostatin / latent myostatin antibody binds specifically to both latent myostatin and promyostatin. It should be noted that “latent myostatin” and “promyostatin” may also be referred to in this descriptive report as “latent GDF8” and “pro-GDF8”, respectively.

[00119] As used in this descriptive report, the term “mature myostatin” refers to a mature, biologically active form of myostatin. In some embodiments, mature myostatin is capable of binding and / or activation of the myostatin receptor. The activation and release of mature myostatin in vivo from its promyostatin form are achieved by several distinct protease cleavage events. To begin, “promyostatin” is cleaved by a proprotein convertase, resulting in “latent myostatin,” in which mature myostatin is shielded from binding to its receptors by a portion of the prodomain. The activation and release of mature myostatin are achieved after cleavage of latent myostatin by an additional BMP / toloid family protease, for example, mTLL-2. See, for example, Figures 1A, 1B, and 2.As used in this descriptive report, the term "mature myostatin" can refer to both full-length mature myostatin and fragments of full-length mature myostatin that retain biological activity. Exemplary mature myostatin sequences, variants thereof, and methods for generating mature myostatin are well known in the art and described in more detail in this descriptive report. Petition 870210013044, dated 08 / 02 / 2021, page 51 / 205 42 / 190

[00120] The term promyostatin, also known as pro-GDF8, refers to an inactive precursor of mature myostatin, comprising a disulfide-linked homodimer, each molecule of the homodimer comprising the amino-terminal prodomain covalently linked to the carboxyl-terminal domain of mature myostatin. In one embodiment, promyostatin has not been cleaved by a proprotein convertase, or a protease of the BMP / toloid family. Exemplary promyostatin sequences, variants thereof, and methods of promyostatin generation are well known in the art and described in more detail in this descriptive report.

[00121] As used in this descriptive report, the term latent myostatin refers to an inactive precursor of mature myostatin, comprising a disulfide-linked homodimer, each molecule of the homodimer comprising the amino-terminal prodomain non-covalently linked to the carboxyl-terminal domain of mature myostatin. In one embodiment, latent myostatin is generated from a promyostatin that has been cleaved by a proprotein convertase but not cleaved by a BMP / toloid family protease. In another embodiment, latent myostatin can be generated by combining the prodomain and the carboxyl-terminal domain of mature myostatin in vitro and allowing them to fold appropriately. See, for example, Sengle et al., J. Biol. Chem. , 286 (7) : 5.0875.099, 2011. Exemplary latent myostatin sequences, variants thereof, and methods of latent myostatin generation are well known in the art and described in more detail in this descriptive report.

[00122] As used in this descriptive report, the term Petition 870210013044, dated 08 / 02 / 2021, page 52 / 205 42 / 190

[00120] The term promyostatin, also known as pro-GDF8, refers to an inactive precursor of mature myostatin, comprising a disulfide-linked homodimer, each molecule of the homodimer comprising the amino-terminal prodomain covalently linked to the carboxyl-terminal domain of mature myostatin. In one embodiment, promyostatin has not been cleaved by a proprotein convertase, or a protease of the BMP / toloid family. Exemplary promyostatin sequences, variants thereof, and methods of promyostatin generation are well known in the art and described in more detail in this descriptive report.

[00121] As used in this descriptive report, the term latent myostatin refers to an inactive precursor of mature myostatin, comprising a disulfide-linked homodimer, each molecule of the homodimer comprising the amino-terminal prodomain non-covalently linked to the carboxyl-terminal domain of mature myostatin. In one embodiment, latent myostatin is generated from a promyostatin that has been cleaved by a proprotein convertase but not cleaved by a BMP / toloid family protease. In another embodiment, latent myostatin can be generated by combining the prodomain and the carboxyl-terminal domain of mature myostatin in vitro and allowing them to fold appropriately. See, for example, Sengle et al., J. Biol. Chem. , 286 (7) : 5.0875.099, 2011. Exemplary latent myostatin sequences, variants thereof, and methods of latent myostatin generation are well known in the art and described in more detail in this descriptive report.

[00122] As used in this descriptive report, the term Petition 870210013044, dated 08 / 02 / 2021, page 52 / 205 "43 / 190 promyostatin / latent myostatin" refers to promyostatin, latent myostatin, or both promyostatin and latent myostatin. In one embodiment, an antibody disclosed in this descriptive report binds to promyostatin. In another embodiment, an antibody disclosed in this descriptive report binds to latent myostatin. In yet another embodiment, an antibody disclosed in this descriptive report binds to both promyostatin and latent myostatin.

[00123] As used in this descriptive report, the term “pure promyostatin” or “pure proGDF8” refers to a composition comprising promyostatin that is free, or substantially free, of other forms of myostatin, for example, latent myostatin and mature myostatin. In one embodiment, an antibody disclosed in this descriptive report binds specifically to pure promyostatin. In other words, such an antibody binds to promyostatin in a composition devoid of the other forms of myostatin, latent myostatin and mature myostatin.

[00124] As used in this descriptive report, the term “proprotein convertase cleavage site” refers to a site where promyostatin is cleaved by a proprotein convertase. In one embodiment, a proprotein convertase cleavage site is a conserved RXXR site between the prodomain and the biologically active domain, or mature myostatin. See, for example, Figures 1A, 1B, and 2.

[00125] As used in this descriptive report, the term “BMP / toloid family protease cleavage site” refers to a site where latent myostatin is cleaved by a member of the BMP / toloid protease family. In one embodiment, a member of the BMP / toloid protease family is mTLL-2. See, Petition 870210013044, dated 08 / 02 / 2021, p. 53 / 205 "43 / 190 promyostatin / latent myostatin" refers to promyostatin, latent myostatin, or both promyostatin and latent myostatin. In one embodiment, an antibody disclosed in this descriptive report binds to promyostatin. In another embodiment, an antibody disclosed in this descriptive report binds to latent myostatin. In yet another embodiment, an antibody disclosed in this descriptive report binds to both promyostatin and latent myostatin.

[00123] As used in this descriptive report, the term “pure promyostatin” or “pure proGDF8” refers to a composition comprising promyostatin that is free, or substantially free, of other forms of myostatin, for example, latent myostatin and mature myostatin. In one embodiment, an antibody disclosed in this descriptive report binds specifically to pure promyostatin. In other words, such an antibody binds to promyostatin in a composition devoid of the other forms of myostatin, latent myostatin and mature myostatin.

[00124] As used in this descriptive report, the term “proprotein convertase cleavage site” refers to a site where promyostatin is cleaved by a proprotein convertase. In one embodiment, a proprotein convertase cleavage site is a conserved RXXR site between the prodomain and the biologically active domain, or mature myostatin. See, for example, Figures 1A, 1B, and 2.

[00125] As used in this descriptive report, the term “BMP / toloid family protease cleavage site” refers to a site where latent myostatin is cleaved by a member of the BMP / toloid protease family. In one embodiment, a member of the BMP / toloid protease family is mTLL-2. See, Petition 870210013044, dated 08 / 02 / 2021, p. 53 / 205 44 / 190 for example, Figures 1A, 1B and 2. Antibodies that bind to promyostatin / latent myostatin

[00126] The present disclosure is based, at least in part, on the surprising discovery that certain promyostatin / latent myostatin-specific antibodies (e.g., an antibody referred to in this descriptive report as Ab1) prevented the proteolytic activation of promyostatin / latent myostatin into mature myostatin. Furthermore, inhibition of myostatin activation using these antibodies was effective in increasing muscle mass in mouse models of muscle atrophy induced by both dexamethasone and castration. Aspects of the disclosure provide antibodies (e.g., antibodies and antigen-binding fragments) that bind to promyostatin / latent myostatin and inhibit the proteolytic activation of promyostatin / latent myostatin into mature myostatin.

[00127] An antibody (used interchangeably with the plural form) is an immunoglobulin molecule capable of specific binding to a target, for example, a carbohydrate, polynucleotide, lipid, polypeptide, etc., through at least one antigen recognition site located in the variable region of the immunoglobulin molecule. As used in this descriptive report, the term antibody encompasses not only intact (e.g., full-length) polyclonal or monoclonal antibodies, but also antigen-binding fragments thereof (e.g., Fab, Fab', F(ab')2, Fv), single-strand (scFv), mutants thereof, fusion proteins comprising an antibody portion, humanized antibodies, chimeric antibodies, diabodies, antibodies Petition 870210013044, dated 08 / 02 / 2021, p. 54 / 205 44 / 190 for example, Figures 1A, 1B and 2. Antibodies that bind to promyostatin / latent myostatin

[00126] The present disclosure is based, at least in part, on the surprising discovery that certain promyostatin / latent myostatin-specific antibodies (e.g., an antibody referred to in this descriptive report as Ab1) prevented the proteolytic activation of promyostatin / latent myostatin into mature myostatin. Furthermore, inhibition of myostatin activation using these antibodies was effective in increasing muscle mass in mouse models of muscle atrophy induced by both dexamethasone and castration. Aspects of the disclosure provide antibodies (e.g., antibodies and antigen-binding fragments) that bind to promyostatin / latent myostatin and inhibit the proteolytic activation of promyostatin / latent myostatin into mature myostatin.

[00127] An antibody (used interchangeably with the plural form) is an immunoglobulin molecule capable of specific binding to a target, for example, a carbohydrate, polynucleotide, lipid, polypeptide, etc., through at least one antigen recognition site located in the variable region of the immunoglobulin molecule. As used in this descriptive report, the term antibody encompasses not only intact (e.g., full-length) polyclonal or monoclonal antibodies, but also antigen-binding fragments thereof (e.g., Fab, Fab', F(ab')2, Fv), single-strand (scFv), mutants thereof, fusion proteins comprising an antibody portion, humanized antibodies, chimeric antibodies, diabodies, antibodies Petition 870210013044, dated 08 / 02 / 2021, page 54 / 205 45 / 190 linear, single-chain antibodies, multispecific antibodies (e.g., bispecific antibodies), and any other modified configuration of the immunoglobulin molecule comprising an antigen recognition site of the required specificity, including antibody glycosylation variants, antibody amino acid sequence variants, and covalently modified antibodies. An antibody includes an antibody of any class, for example, IgD, IgE, IgG, IgA, or IgM (or a subclass thereof), and the antibody need not be of any particular class. Depending on the amino acid sequence of the antibody's constant domain of its heavy chains, immunoglobulins can be classified into different classes. There are five main classes of immunoglobulins: IgA, IgD, IgE, IgG, and IgM, and several of these can be further divided into subclasses (isotypes), for example, IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2.The constant domains of the heavy chain that correspond to the different classes of immunoglobulins are designated alpha, delta, epsilon, gamma, and mu, respectively. The subunit structures and three-dimensional configurations of different classes of immunoglobulins are well known.

[00128] An “isolated antibody,” as used in this report, is intended to refer to an antibody that is substantially free of other antibodies that have different antigenic specificities (for example, an isolated antibody that specifically binds to promyostatin / latent myostatin is substantially free of antibodies that specifically bind to antigens other than promyostatin / latent myostatin). A Petition 870210013044, dated 08 / 02 / 2021, page 55 / 205 45 / 190 linear, single-chain antibodies, multispecific antibodies (e.g., bispecific antibodies), and any other modified configuration of the immunoglobulin molecule comprising an antigen recognition site of the required specificity, including antibody glycosylation variants, antibody amino acid sequence variants, and covalently modified antibodies. An antibody includes an antibody of any class, for example, IgD, IgE, IgG, IgA, or IgM (or a subclass thereof), and the antibody need not be of any particular class. Depending on the amino acid sequence of the antibody's constant domain of its heavy chains, immunoglobulins can be classified into different classes. There are five main classes of immunoglobulins: IgA, IgD, IgE, IgG, and IgM, and several of these can be further divided into subclasses (isotypes), for example, IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2.The constant domains of the heavy chain that correspond to the different classes of immunoglobulins are designated alpha, delta, epsilon, gamma, and mu, respectively. The subunit structures and three-dimensional configurations of different classes of immunoglobulins are well known.

[00128] An “isolated antibody,” as used in this report, is intended to refer to an antibody that is substantially free of other antibodies that have different antigenic specificities (for example, an isolated antibody that specifically binds to promyostatin / latent myostatin is substantially free of antibodies that specifically bind to antigens other than promyostatin / latent myostatin). A Petition 870210013044, dated 08 / 02 / 2021, page 55 / 205 46 / 190 isolated antibody that binds specifically to promyostatin / latent myostatin may, however, have cross-reactivity to other antigens, for example, promyostatin / latent myostatin molecules from other species. Furthermore, an isolated antibody may be substantially free of cellular material and / or chemicals.

[00129] The term “human antibody,” as used in this report, is intended to include antibodies that possess variable and constant regions derived from human germline immunoglobulin sequences, and fragments thereof. Human antibodies of discovery may include amino acid residues not encoded by human germline immunoglobulin sequences (e.g., mutations introduced by random or site-specific mutagenesis in vitro or by somatic mutation in vivo), for example, in CDRs and, in particular, CDR3. However, the term “human antibody,” as used in this report, is not intended to include antibodies in which germline-derived CDR sequences from another mammalian species, e.g., a mouse, have been grafted onto human scaffold sequences.

[00130] The term “epitope” includes any polypeptide determinant capable of specific binding to an immunoglobulin or T-cell receptor. In certain embodiments, epitope determinants include chemically active surface clusters of molecules such as, for example, amino acids, sugar side chains, phosphoryl or sulfonyl groups, and in certain embodiments, they may have specific three-dimensional structural features. Petition 870210013044, dated 08 / 02 / 2021, p. 56 / 205 46 / 190 isolated antibody that binds specifically to promyostatin / latent myostatin may, however, cross-react to other antigens, for example, promyostatin / latent myostatin molecules from other species. Furthermore, an isolated antibody may be substantially free of cellular material and / or chemicals.

[00129] The term “human antibody,” as used in this report, is intended to include antibodies that possess variable and constant regions derived from human germline immunoglobulin sequences, and fragments thereof. Human antibodies of discovery may include amino acid residues not encoded by human germline immunoglobulin sequences (e.g., mutations introduced by random or site-specific mutagenesis in vitro or by somatic mutation in vivo), for example, in CDRs and, in particular, CDR3. However, the term “human antibody,” as used in this report, is not intended to include antibodies in which germline-derived CDR sequences from another mammalian species, e.g., a mouse, have been grafted onto human scaffold sequences.

[00130] The term “epitope” includes any polypeptide determinant capable of specific binding to an immunoglobulin or T-cell receptor. In certain embodiments, epitope determinants include chemically active surface clusters of molecules such as, for example, amino acids, sugar side chains, phosphoryl or sulfonyl groups, and in certain embodiments, they may have specific three-dimensional structural features. Petition 870210013044, dated 08 / 02 / 2021, p. 56 / 205 47 / 190 and / or specific charge characteristics. An epitope is a region of an antigen that is bound by an antibody. In certain embodiments, an antibody is said to bind specifically to an antigen when it preferentially recognizes its target antigen in a complex mixture of proteins and / or macromolecules.

[00131] The antibodies described in this descriptive report are capable of binding to latent promyostatin / myostatin, thereby inhibiting the proteolytic activation of latent promyostatin / myostatin into mature myostatin. In some cases, the antibodies described in this descriptive report can inhibit the proteolytic activation of latent promyostatin / myostatin by at least 20%, for example, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95% or greater. In some cases, the antibodies described in this descriptive report may inhibit the proteolytic cleavage of promyostatin by a proprotein convertase (e.g., furin) by at least 20%, for example, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, or higher. In some cases, the antibodies described in this descriptive report may inhibit the proteolytic cleavage of promyostatin or latent myostatin by a toloid protease (e.g., mTLL2) by at least 20%, for example, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, or higher. The inhibitory activity of an anti-promyostatin / latent myostatin antibody can be measured by routine methods, for example, by Western blot analysis, as described in Example 1 and FIGURE 3. However, it should be noted that additional methods may be used to measure the inhibitory activity of an anti-promyostatin / latent myostatin antibody on proteolytic cleavage. Petition 870210013044, dated 08 / 02 / 2021, page 57 / 205 47 / 190 and / or specific charge characteristics. An epitope is a region of an antigen that is bound by an antibody. In certain embodiments, an antibody is said to bind specifically to an antigen when it preferentially recognizes its target antigen in a complex mixture of proteins and / or macromolecules.

[00131] The antibodies described in this descriptive report are capable of binding to latent promyostatin / myostatin, thereby inhibiting the proteolytic activation of latent promyostatin / myostatin into mature myostatin. In some cases, the antibodies described in this descriptive report can inhibit the proteolytic activation of latent promyostatin / myostatin by at least 20%, for example, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95% or greater. In some cases, the antibodies described in this descriptive report may inhibit the proteolytic cleavage of promyostatin by a proprotein convertase (e.g., furin) by at least 20%, for example, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, or higher. In some cases, the antibodies described in this descriptive report may inhibit the proteolytic cleavage of promyostatin or latent myostatin by a toloid protease (e.g., mTLL2) by at least 20%, for example, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, or higher. The inhibitory activity of an anti-promyostatin / latent myostatin antibody can be measured by routine methods, for example, by Western blot analysis, as described in Example 1 and FIGURE 3. However, it should be noted that additional methods may be used to measure the inhibitory activity of an anti-promyostatin / latent myostatin antibody on proteolytic cleavage. Petition 870210013044, dated 08 / 02 / 2021, page 57 / 205 48 / 190 of promyostatin / latent myostatin. In some embodiments, the inhibition of promyostatin / latent myostatin cleavage (e.g., by a proprotein convertase and / or toloid protease) can be reflected as an inhibition constant (Ki), which provides a measure of inhibitory potency, and which is the concentration of inhibitor (e.g., an anti-promyostatin / latent myostatin antibody) required to reduce protease activity (e.g., of a proprotein convertase or toloid protease) by half and is not dependent on enzyme or substrate concentrations.

[00132] In some embodiments, a proprotein convertase comprises (i) a catalytic domain that hydrolyzes a peptide bond of a protein containing a proprotein convertase cleavage site, and (ii) a binding cavity that binds to an rTGF with a proprotein convertase cleavage site. Examples of proprotein convertases for use according to the present disclosure include, without limitation, PCSK5 / 6, PACE4, PACE7, and PACE3 (e.g., furin). A proprotein convertase, in some embodiments, is obtained from any mammal including, without limitation, humans, monkeys, or rodents (e.g., mice, rats, hamsters).

[00133] In some embodiments, a proprotein convertase is homologous to a proprotein convertase selected from the group consisting of: PCSK5 / 6, PACE4, PACE7 and PACE3 (e.g., furin). For example, a proprotein convertase may be at least 70% identical, at least 80% identical, at least 90% identical, at least 95% identical, at least 96% identical, at least 97% identical, at least Petition 870210013044, dated 08 / 02 / 2021, p. 58 / 205 48 / 190 of promyostatin / latent myostatin. In some embodiments, the inhibition of promyostatin / latent myostatin cleavage (e.g., by a proprotein convertase and / or toloid protease) can be reflected as an inhibition constant (Ki), which provides a measure of inhibitory potency, and which is the concentration of inhibitor (e.g., an anti-promyostatin / latent myostatin antibody) required to reduce protease activity (e.g., of a proprotein convertase or toloid protease) by half and is not dependent on enzyme or substrate concentrations.

[00132] In some embodiments, a proprotein convertase comprises (i) a catalytic domain that hydrolyzes a peptide bond of a protein containing a proprotein convertase cleavage site, and (ii) a binding cavity that binds to an rTGF with a proprotein convertase cleavage site. Examples of proprotein convertases for use according to the present disclosure include, without limitation, PCSK5 / 6, PACE4, PACE7, and PACE3 (e.g., furin). A proprotein convertase, in some embodiments, is obtained from any mammal including, without limitation, humans, monkeys, or rodents (e.g., mice, rats, hamsters).

[00133] In some embodiments, a proprotein convertase is homologous to a proprotein convertase selected from the group consisting of: PCSK5 / 6, PACE4, PACE7 and PACE3 (e.g., furin). For example, a proprotein convertase may be at least 70% identical, at least 80% identical, at least 90% identical, at least 95% identical, at least 96% identical, at least 97% identical, at least Petition 870210013044, dated 08 / 02 / 2021, p. 58 / 205 49 / 190 98% identical, at least 99% identical, at least 99.5% identical, or at least approximately 99.9% identical to PCSK5 / 6, PACE4, PACE7, or PACE3 (e.g., furin).

[00134] A proprotein convertase cleavage site, in some embodiments, is an amino sequence that can be cleaved by a proprotein convertase (e.g., PCSK5 / 6, PACE4, PACE7, and PACE3). In some embodiments, the proprotein convertase cleavage site comprises the amino acid sequence RXXR, where R is arginine and X is any amino acid. In some embodiments, the proprotein convertase cleavage site comprises the amino acid sequence RX-(K / R)-R, where R is arginine, K is lysine, and X is any amino acid. In some embodiments, the proprotein convertase cleavage site comprises the amino acid sequence RVRR (SEQ ID No.: 57), where R is arginine and V is valine. Exemplary proprotein convertase cleavage sites for human, rat, mouse, and Cynomolgus myostatin are shown in bold in IDS. DE SEQ. Nos: 52-55.In some embodiments, the proprotein convertase cleavage site comprises the amino acid sequence RSRR (SEQ ID No.: 56).

[00135] In some embodiments, toloid proteases for use according to the present disclosure include, without limitation, BMP-1, mTLL-1, and mTLL-2. A toloid protease may be obtained from any mammal including, without limitation, humans, monkeys, or rodents (e.g., mice, rats, hamsters). In some embodiments, a toloid protease is homologous to a toloid protease selected from the group consisting of: BMP-1, mTLL-1, and mTLL-2. For example, a toloid protease may be at least 70% identical, at least Petition 870210013044, dated 08 / 02 / 2021, p. 59 / 205 49 / 190 98% identical, at least 99% identical, at least 99.5% identical, or at least approximately 99.9% identical to PCSK5 / 6, PACE4, PACE7, or PACE3 (e.g., furin).

[00134] A proprotein convertase cleavage site, in some embodiments, is an amino sequence that can be cleaved by a proprotein convertase (e.g., PCSK5 / 6, PACE4, PACE7, and PACE3). In some embodiments, the proprotein convertase cleavage site comprises the amino acid sequence RXXR, where R is arginine and X is any amino acid. In some embodiments, the proprotein convertase cleavage site comprises the amino acid sequence RX-(K / R)-R, where R is arginine, K is lysine, and X is any amino acid. In some embodiments, the proprotein convertase cleavage site comprises the amino acid sequence RVRR (SEQ ID No.: 57), where R is arginine and V is valine. Exemplary proprotein convertase cleavage sites for human, rat, mouse, and Cynomolgus myostatin are shown in bold in IDS. DE SEQ. Nos: 52-55.In some embodiments, the proprotein convertase cleavage site comprises the amino acid sequence RSRR (SEQ ID No.: 56).

[00135] In some embodiments, toloid proteases for use according to the present disclosure include, without limitation, BMP-1, mTLL-1, and mTLL-2. A toloid protease may be obtained from any mammal including, without limitation, humans, monkeys, or rodents (e.g., mice, rats, hamsters). In some embodiments, a toloid protease is homologous to a toloid protease selected from the group consisting of: BMP-1, mTLL-1, and mTLL-2. For example, a toloid protease may be at least 70% identical, at least Petition 870210013044, dated 08 / 02 / 2021, p. 59 / 205 50 / 190 minus 80% identical, at least 90% identical, at least 95% identical, at least 96% identical, at least 97% identical, at least 98% identical, at least 99% identical, at least 99.5% identical, or at least approximately 99.9% identical to BMP1, mTLL-1, and mTLL-2.

[00136] A toloid protease cleavage site, in some embodiments, is an amino sequence that can be cleaved by a toloid (e.g., BMP-1, mTLL-1, and mTLL2). Exemplary toloid protease cleavage sites for human, rat, mouse, and Cynomolgus myostatin are shown, in underline, in IDS. DE SEQ. Nos: 52-55. In some embodiments, the toloid cleavage site comprises the amino acid sequence QR, where Q is glutamine and R is arginine.

[00137] In some embodiments, the antibodies described in this descriptive report are capable of binding to a latent promyostatin / myostatin, thereby inhibiting myostatin activity. In some cases, the antibodies described in this descriptive report can inhibit myostatin signaling by at least 20%, for example, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, or more. In some embodiments, the inhibition of myostatin signaling can be measured by routine methods, for example, using a myostatin activation assay, as described in Example 1. However, it should be noted that additional methods can be used to measure myostatin signaling activity.

[00138] It should be noted that the extent of proteolytic cleavage of myostatin, for example by a proprotein convertase and / or a toloid protease, may be Petition 870210013044, dated 08 / 02 / 2021, page 60 / 205 50 / 190 minus 80% identical, at least 90% identical, at least 95% identical, at least 96% identical, at least 97% identical, at least 98% identical, at least 99% identical, at least 99.5% identical, or at least approximately 99.9% identical to BMP1, mTLL-1, and mTLL-2.

[00136] A toloid protease cleavage site, in some embodiments, is an amino sequence that can be cleaved by a toloid (e.g., BMP-1, mTLL-1, and mTLL2). Exemplary toloid protease cleavage sites for human, rat, mouse, and Cynomolgus myostatin are shown, in underline, in IDS. DE SEQ. Nos: 52-55. In some embodiments, the toloid cleavage site comprises the amino acid sequence QR, where Q is glutamine and R is arginine.

[00137] In some embodiments, the antibodies described in this descriptive report are capable of binding to a latent promyostatin / myostatin, thereby inhibiting myostatin activity. In some cases, the antibodies described in this descriptive report can inhibit myostatin signaling by at least 20%, for example, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, or more. In some embodiments, the inhibition of myostatin signaling can be measured by routine methods, for example, using a myostatin activation assay, as described in Example 1. However, it should be noted that additional methods can be used to measure myostatin signaling activity.

[00138] It should be noted that the extent of proteolytic cleavage of myostatin, for example by a proprotein convertase and / or a toloid protease, may be Petition 870210013044, dated 08 / 02 / 2021, page 60 / 205 51 / 190 measured and / or quantified using any suitable method. In some embodiments, the extent of myostatin proteolytic cleavage is measured and / or quantified using an enzyme-linked immunosorbent assay (ELISA). For example, an ELISA can be used to measure the level of released growth factor (e.g., mature myostatin). As another example, an antibody that binds specifically to promyostatin, latent myostatin, and / or mature myostatin can be used in an ELISA to measure the level of a specific form of myostatin (e.g., promyostatin / latent myostatin / mature myostatin) to quantify the extent of myostatin proteolytic cleavage.In some modalities, the extent of myostatin proteolytic cleavage is measured and / or quantified using immunoprecipitation, followed by SDS-PAGE or tryptic peptide mass spectrometry, fluorescence anisotropy-based techniques, FRET assays, hydrogen-deuterium exchange mass spectrometry, and / or NMR spectroscopy.

[00139] In some forms, antibodies, also known as immunoglobulins, are tetrameric glycosylated proteins composed of two light chains (L) of approximately 25 kDa each and two heavy chains (H) of approximately 50 kDa each. Two types of light chain, called lambda and kappa, can be found in antibodies. Depending on the amino acid sequence of the constant domain of heavy chains, immunoglobulins can be distributed into five main classes: A, D, E, G, and M, and several of these can be further divided into subclasses (isotypes), for example, IgG1, IgG2, IgG3, IgG4, Petition 870210013044, dated 08 / 02 / 2021, p. 61 / 205 51 / 190 measured and / or quantified using any suitable method. In some embodiments, the extent of myostatin proteolytic cleavage is measured and / or quantified using an enzyme-linked immunosorbent assay (ELISA). For example, an ELISA can be used to measure the level of released growth factor (e.g., mature myostatin). As another example, an antibody that binds specifically to promyostatin, latent myostatin, and / or mature myostatin can be used in an ELISA to measure the level of a specific form of myostatin (e.g., promyostatin / latent myostatin / mature myostatin) to quantify the extent of myostatin proteolytic cleavage.In some modalities, the extent of myostatin proteolytic cleavage is measured and / or quantified using immunoprecipitation, followed by SDS-PAGE or tryptic peptide mass spectrometry, fluorescence anisotropy-based techniques, FRET assays, hydrogen-deuterium exchange mass spectrometry, and / or NMR spectroscopy.

[00139] In some forms, antibodies, also known as immunoglobulins, are tetrameric glycosylated proteins composed of two light chains (L) of approximately 25 kDa each and two heavy chains (H) of approximately 50 kDa each. Two types of light chain, called lambda and kappa, can be found in antibodies. Depending on the amino acid sequence of the constant domain of heavy chains, immunoglobulins can be distributed into five main classes: A, D, E, G, and M, and several of these can be further divided into subclasses (isotypes), for example, IgG1, IgG2, IgG3, IgG4, Petition 870210013044, dated 08 / 02 / 2021, p. 61 / 205 52 / 190 IgA1 and IgA2. Each light chain typically includes an N-terminal variable (V) domain (Vl) and a constant (C) domain (CL). Each heavy chain typically includes an N-terminal V domain (Vh), three or four C domains (Ch1-3), and a hinge region. The CH domain most proximal to Vh is designated Ch1. The Vh and Vl domains consist of four relatively conserved sequence regions called scaffold regions (FR1, FR2, FR3, and FR4), which form a scaffold for three hypervariable sequence regions (complementarity-determining regions, CDRs). The CDRs contain most of the residues responsible for specific antibody-antigen interactions. The CDRs are designated CDR1, CDR2, and CDR3. Consequently, the constituents of CDR in the heavy chain are designated CDRH1, CDRH2, and CDRH3, while the constituents of CDR in the light chain are designated CDRL1, CDRL2, and CDRL3.CDRs typically refer to Kabat CDRs, as described in "Sequences of Proteins of Immunological Interest," "US. Department of Health and Human Services” (1991), eds. Kabat et al. Another standard for characterizing the antigen-binding site is the reference to hypervariable loops, as described by Chothia. See, for example, Chothia, D. et al., (1992) J. Mol. Biol. 227: 799-817; and Tomlinson et al., (1995) EMBO J. 14: 4628-4638. Yet another standard is the definition of AbM used by “Oxford Molecular's AbM Antibody Modeling Software”. See, generally, for example, “Protein Sequence and Structure Analysis of Antibody Variable Domains”. In: “Antibody Engineering Lab Manual” (Ed.: (Duebel, S. and Kontermann, R., Springer-Verlag, Heidelberg). Modalities described in relation to Kabat's CDRs may Petition 870210013044, dated 08 / 02 / 2021, page 62 / 205 52 / 190 IgA1 and IgA2. Each light chain typically includes an N-terminal variable (V) domain (Vl) and a constant (C) domain (CL). Each heavy chain typically includes an N-terminal V domain (Vh), three or four C domains (Ch1-3), and a hinge region. The CH domain most proximal to Vh is designated Ch1. The Vh and Vl domains consist of four relatively conserved sequence regions called scaffold regions (FR1, FR2, FR3, and FR4), which form a scaffold for three hypervariable sequence regions (complementarity-determining regions, CDRs). The CDRs contain most of the residues responsible for specific antibody-antigen interactions. The CDRs are designated CDR1, CDR2, and CDR3. Consequently, the constituents of CDR in the heavy chain are designated CDRH1, CDRH2, and CDRH3, while the constituents of CDR in the light chain are designated CDRL1, CDRL2, and CDRL3.CDRs typically refer to Kabat CDRs, as described in "Sequences of Proteins of Immunological Interest," "US. Department of Health and Human Services” (1991), eds. Kabat et al. Another standard for characterizing the antigen-binding site is the reference to hypervariable loops, as described by Chothia. See, for example, Chothia, D. et al., (1992) J. Mol. Biol. 227: 799-817; and Tomlinson et al., (1995) EMBO J. 14: 4628-4638. Yet another standard is the definition of AbM used by “Oxford Molecular's AbM Antibody Modeling Software”. See, generally, for example, “Protein Sequence and Structure Analysis of Antibody Variable Domains”. In: “Antibody Engineering Lab Manual” (Ed.: (Duebel, S. and Kontermann, R., Springer-Verlag, Heidelberg). Modalities described in relation to Kabat's CDRs may Petition 870210013044, dated 08 / 02 / 2021, page 62 / 205 53 / 190 can alternatively be implemented using similarly described relationships with respect to Chothia's hypervariable handles or the handles defined by AbM, or combinations of either of these methods.

[00140] In some embodiments, the anti-promyostatin / latent myostatin antibodies of the present disclosure and the nucleic acid molecules of the present disclosure encoding the antibodies include the CDR amino acid sequences shown in Table 1. Table 1. Anticorpo CDRH1 CDRH2 CDRH3 CDRL1 CDRL2 CDRL3 (IDS. DE (IDS. DE (IDS. DE (IDS. DE) SEQ. Nos: SEQ. Nos: SEQ. Nos: SEQ. Nos: 12- SEQ. Nos: SEQ. Nos: 1-3) 4-9) 10-11) 17) 18-21) 22-23) Ab1 Kabat: SSYGMH (ID. VISYDGSNKYYA DLLVRFLEWS SGSSSNIGSNTV SDNQRPS AAWDDSLNGV DE SEQ. N°: DSVKG (ID. HH (ID. DE (ID. DE (ID. DE 1) DE SEQ. N°: YYGMDV SEQ. N°: 12) SEQ. N°: SEQ. N°: 4) (ID. DE 18) 22) IMGT: GFTFSSYGMH ISYDGSN (ID. SEQ. DLLVRFLEWS SGSTSNIGSNTV SDDQRPS AAWDESLNGV DE SEQ. GFAFSSYGMH ISYDGSI (ID. 11) TSNIGSNT SDD (ID. DE (ID. DE SEQ. DE SEQ. N°: (ID. DE SEQ. SEQ. N°: N°: 3) 7) N°: 15) 21) Petition: 870210013044, on 02 / 08 / 2021, page. 63 / 205 53 / 190 can alternatively be implemented using similarly described relationships with respect to Chothia's hypervariable handles or the handles defined by AbM, or combinations of either of these methods.

[00140] In some embodiments, the anti-promyostatin / latent myostatin antibodies of the present disclosure and the nucleic acid molecules of the present disclosure encoding the antibodies include the CDR amino acid sequences shown in Table 1. Table 1. Anticorpo CDRH1 CDRH2 CDRH3 CDRL1 CDRL2 CDRL3 (IDS. DE (IDS. DE (IDS. DE (IDS. DE) SEQ. Nos: SEQ. Nos: SEQ. Nos: SEQ. Nos: 12- SEQ. Nos: SEQ. Nos: 1-3) 4-9) 10-11) 17) 18-21) 22-23) Ab1 Kabat: SSYGMH (ID. VISYDGSNKYYA DLLVRFLEWS SGSSSNIGSNTV SDNQRPS AAWDDSLNGV DE SEQ. N°: DSVKG (ID. HH (ID. DE (ID. DE (ID. DE 1) DE SEQ. N°: YYGMDV SEQ. N°: 12) SEQ. N°: SEQ. N°: 4) (ID. DE 18) 22) IMGT: GFTFSSYGMH ISYDGSN (ID. SEQ. DLLVRFLEWS SGSTSNIGSNTV SDDQRPS AAWDESLNGV DE SEQ. GFAFSSYGMH ISYDGSI (ID. 11) TSNIGSNT SDD (ID. DE (ID. DE SEQ. DE SEQ. N°: (ID. DE SEQ. SEQ. N°: N°: 3) 7) N°: 15) 21) Petition: 870210013044, on 02 / 08 / 2021, page. 63 / 205 54 / 190 Ab5 Kabat: SYGMH (ID. 16) 20) N°: 23) 8) IMGT: GFAFSSYGMH ISYDGNN (ID. SSNIGGNT (ID. SDD (ID. DE (ID. DE SEQ. DE SEQ. N°: DE SEQ. N°: SEQ. N°: 21) N°: 3) 9) 17) Na Tabela 1, as sequências únicas de CDRH3 e CDRL3 refletem Kabat e IMGT.

[00141] In some embodiments, antipromyostatin / latent myostatin binding agents (e.g., antibodies) of the development include any antibody (including antigen-binding fragments) that includes a CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, or CDRL3, or combinations thereof, as provided for any of the antibodies shown in Table 1. In some embodiments, antipromyostatin / latent myostatin binding agents include the CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 of any of the antibodies shown in Table 1. The development also includes any nucleic acid sequence encoding a molecule comprising a CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, or CDRL3 as provided for any of the antibodies shown in Table 1. The CDR3 heavy and light chain domains of the antibody may have a particularly important role in the specificity / affinity of binding. an antibody for an antigen.Consequently, latent antipromyostatin / myostatin-releasing binding agents, or their nucleic acid molecules, may include at least the heavy and / or light chain CDR3s of antibodies, such as... Petition 870210013044, dated 08 / 02 / 2021, p. 64 / 205 54 / 190 Ab5 Kabat: SYGMH (ID. OF VISYDGNNKYYA DLLVRFLEWSHKY SGSSSNIGGNTVH SDDQRPS (ID. AAWDESLNGV SEQ. NO.: 1) DSVKG (ID. GMDV (ID. OF (ID. OF SEQ. OF SEQ. NO.: (ID. OF SEQ. OF SEQ. NO.: SEQ. NO.: 11) NO.: 16) 20) No.: 23) 8) IMGT: GFAFSSYGMH ISYDGNN (ID. SSNIGGNT (ID. SDD (ID. OF (SEQ. ID. OF SEQ. NO.: OF SEQ. NO.: SEQ. NO.: 21) NO.: 3) 9) 17) In Table 1, the unique sequences of CDRH3 and CDRL3 reflect Kabat and IMGT.

[00141] In some embodiments, antipromyostatin / latent myostatin binding agents (e.g., antibodies) of the development include any antibody (including antigen-binding fragments) that includes a CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, or CDRL3, or combinations thereof, as provided for any of the antibodies shown in Table 1. In some embodiments, antipromyostatin / latent myostatin binding agents include the CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 of any of the antibodies shown in Table 1. The development also includes any nucleic acid sequence encoding a molecule comprising a CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, or CDRL3 as provided for any of the antibodies shown in Table 1. The CDR3 heavy and light chain domains of the antibody may have a particularly important role in the specificity / affinity of binding. an antibody for an antigen.Consequently, latent antipromyostatin / myostatin-releasing binding agents, or their nucleic acid molecules, may include at least the heavy and / or light chain CDR3s of antibodies, such as... Petition 870210013044, dated 08 / 02 / 2021, p. 64 / 205 55 / 190 shown in Table 1.

[00142] Aspects of the revelation are related to a monoclonal antibody or antigen-binding fragment that binds to the promyostatin / myostatin latent protein and comprises six complementarity-determining regions (CDRs): CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3.

[00143] In some embodiments, CDRH1 comprises a sequence as shown in any of the IDS. DE SEQ. Nos: 1-3. In some embodiments, CDRH2 comprises a sequence as shown in any of the IDS. DE SEQ. Nos: 4-9. In some embodiments, CDRH3 comprises a sequence as shown in any of the IDS. DE SEQ. Nos: 10-11. CDRL1 comprises a sequence as shown in any of the IDS. DE SEQ. Nos: 12-17. In some embodiments, CDRL2 comprises a sequence as shown in any of the IDS. DE SEQ. Nos: 18-21. In some embodiments, CDRL3 comprises a sequence as shown in any of the IDS. DE SEQ. Nos: 22-23.

[00144] In some embodiments (for example, as for the anti-promyostatin / latent myostatin antibody Ab1, shown in Table 1), CDRH1 comprises a sequence as shown in SEQ. ID No.: 1 or 2, CDRH2 comprises a sequence as shown in SEQ. ID No.: 4 or 5, CDRH3 comprises a sequence as shown in SEQ. ID No.: 10, CDRL1 comprises a sequence as shown in SEQ. ID No.: 12 or 13, CDRL2 comprises a sequence as shown in SEQ. ID No.: 18 or 19, and CDRL3 comprises a sequence as shown in SEQ. ID No.: 22, and the antibody binds to promyostatin / latent myostatin. Petition 870210013044, dated 08 / 02 / 2021, p. 65 / 205 55 / 190 shown in Table 1.

[00142] Aspects of the revelation are related to a monoclonal antibody or antigen-binding fragment that binds to the promyostatin / myostatin latent protein and comprises six complementarity-determining regions (CDRs): CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3.

[00143] In some embodiments, CDRH1 comprises a sequence as shown in any of the IDS. DE SEQ. Nos: 1-3. In some embodiments, CDRH2 comprises a sequence as shown in any of the IDS. DE SEQ. Nos: 4-9. In some embodiments, CDRH3 comprises a sequence as shown in any of the IDS. DE SEQ. Nos: 10-11. CDRL1 comprises a sequence as shown in any of the IDS. DE SEQ. Nos: 12-17. In some embodiments, CDRL2 comprises a sequence as shown in any of the IDS. DE SEQ. Nos: 18-21. In some embodiments, CDRL3 comprises a sequence as shown in any of the IDS. DE SEQ. Nos: 22-23.

[00144] In some embodiments (for example, as for the anti-promyostatin / latent myostatin antibody Ab1, shown in Table 1), CDRH1 comprises a sequence as shown in SEQ. ID No.: 1 or 2, CDRH2 comprises a sequence as shown in SEQ. ID No.: 4 or 5, CDRH3 comprises a sequence as shown in SEQ. ID No.: 10, CDRL1 comprises a sequence as shown in SEQ. ID No.: 12 or 13, CDRL2 comprises a sequence as shown in SEQ. ID No.: 18 or 19, and CDRL3 comprises a sequence as shown in SEQ. ID No.: 22, and the antibody binds to promyostatin / latent myostatin. Petition 870210013044, dated 08 / 02 / 2021, p. 65 / 205 56 / 190

[00145] In some embodiments (for example, as for the anti-promyostatin / latent myostatin antibody Ab3, shown in Table 1), CDRH1 comprises a sequence as shown in SEQ. ID No.: 1 or 3, CDRH2 comprises a sequence as shown in SEQ. ID No.: 6 or 7, CDRH3 comprises a sequence as shown in SEQ. ID No.: 11, CDRL1 comprises a sequence as shown in SEQ. ID No.: 14 or 15, CDRL2 comprises a sequence as shown in SEQ. ID No.: 20 or 21, and CDRL3 comprises a sequence as shown in SEQ. ID No.: 23, and the antibody binds to promyostatin / latent myostatin.

[00146] In some embodiments (for example, as for the anti-promyostatin / latent myostatin antibody Ab5, shown in Table 1), CDRH1 comprises a sequence as shown in SEQ. ID No.: 1 or 3, CDRH2 comprises a sequence as shown in SEQ. ID No.: 8 or 9, CDRH3 comprises a sequence as shown in SEQ. ID No.: 11, CDRL1 comprises a sequence as shown in SEQ ID No.: 16 or 17, CDRL2 comprises a sequence as shown in SEQ ID No.: 20 or 21, and CDRL3 comprises a sequence as shown in SEQ ID No.: 23, and the antibody binds to promyostatin / latent myostatin. In some examples, any of the antipromyostatin / latent myostatin binding agents (e.g., antibodies) of the development includes any antibody (including antigen-binding fragments) that possesses one or more CDR sequences (e.g., CDRH or CDRL) substantially similar to CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and / or CDRL3. For example, antibodies may include one or more CDR sequences as shown in Table 1 (SEQ IDs Nos.: 1-23) that contain Petition 870210013044, dated 08 / 02 / 2021, p. 66 / 205 56 / 190

[00145] In some embodiments (for example, as for the anti-promyostatin / latent myostatin antibody Ab3, shown in Table 1), CDRH1 comprises a sequence as shown in SEQ. ID No.: 1 or 3, CDRH2 comprises a sequence as shown in SEQ. ID No.: 6 or 7, CDRH3 comprises a sequence as shown in SEQ. ID No.: 11, CDRL1 comprises a sequence as shown in SEQ. ID No.: 14 or 15, CDRL2 comprises a sequence as shown in SEQ. ID No.: 20 or 21, and CDRL3 comprises a sequence as shown in SEQ. ID No.: 23, and the antibody binds to promyostatin / latent myostatin.

[00146] In some embodiments (for example, as for the anti-promyostatin / latent myostatin antibody Ab5, shown in Table 1), CDRH1 comprises a sequence as shown in SEQ. ID No.: 1 or 3, CDRH2 comprises a sequence as shown in SEQ. ID No.: 8 or 9, CDRH3 comprises a sequence as shown in SEQ. ID No.: 11, CDRL1 comprises a sequence as shown in SEQ ID No.: 16 or 17, CDRL2 comprises a sequence as shown in SEQ ID No.: 20 or 21, and CDRL3 comprises a sequence as shown in SEQ ID No.: 23, and the antibody binds to promyostatin / latent myostatin. In some examples, any of the antipromyostatin / latent myostatin binding agents (e.g., antibodies) of the development includes any antibody (including antigen-binding fragments) that possesses one or more CDR sequences (e.g., CDRH or CDRL) substantially similar to CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and / or CDRL3. For example, antibodies may include one or more CDR sequences as shown in Table 1 (SEQ IDs Nos.: 1-23) that contain Petition 870210013044, dated 08 / 02 / 2021, p. 66 / 205 57 / 190 up to 5, 4, 3, 2, or 1 amino acid residue variations, when compared with the corresponding CDR region in any of the IDS. SEQ. Nos: 1-23. The complete amino acid and nucleic acid sequences for the variable heavy chain region and variable light chain region of the antibodies listed in Table 1 are provided below.

[00147] Variable region of the heavy chain - Parental Ab1 QIQLVQSGGGVVQPGRSLRLSCAASGFTFSSYGMHWVRQAPGKGLEWVAVISYDGSNKY YADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARDLLVRFLEWSHYYGMDVWGQ GTTVTVSS (Seq. ID No.: 24) CAGATCCAGCTGGTGCAGTCTGGGGGAGGCGTGGTCCAGCCTGGGAGGTCCCTGAGACT CTCCTGTGCAGCGTCTGGATTCACCTTCAGTAGCTATGGCATGCACTGGGTCCGCCAGG CTCCAGGCAAGGGGCTGGAGTGGGTGGCAGTTATATCATATGATGGAAGTAATAAATAC TATGCAGACTCCGTGAAGGGCCGATTCACCATCTCCAGAGACAATTCCAAGAACACGCT GTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCTGTGTATTACTGTGCGAGAG ATCTCCTGGTGCGATTTTTGGAGTGGTCGCACTACTACGGTATGGACGTCTGGGGCCAA GGGACCACGGTCACCGTCTCCTCA (SEQ ID NO: 38)

[00148] Variable region of the heavy chain - germline of Ab2 QVQLVESGGGVVQPGRSLRLSCAASGFTFSSYGMHWVRQAPGKGLEWVAVISYDGSNKY YADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARDLLVRFLEWSHYYGMDVWGQ GTTVTVSS (ID. DE SEQ. N°: 25) CAGGTGCAGCTGGTGGAGTCTGGGGGAGGCGTGGTCCAGCCTGGGAGGTCCCTGAGACT CTCCTGTGCAGCGTCTGGATTCACCTTCAGTAGCTATGGCATGCACTGGGTCCGCCAGG CTCCAGGCAAGGGGCTGGAGTGGGTGGCAGTTATATCATATGATGGAAGTAATAAATAC TATGCAGACTCCGTGAAGGGCCGATTCACCATCTCCAGAGACAATTCCAAGAACACGCT GTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCTGTGTATTACTGTGCGAGAG ATCTCCTGGTGCGATTTTTGGAGTGGTCGCACTACTACGGTATGGACGTCTGGGGCCAA GGGACCACGGTCACCGTCTCCTCA (SEQ ID NO: 39)

[00149] Variable region of the heavy chain - Parental Ab3 Petition 870210013044, dated 08 / 02 / 2021, page 67 / 205 57 / 190 up to 5, 4, 3, 2, or 1 amino acid residue variations, when compared with the corresponding CDR region in any of the IDS. SEQ. Nos: 1-23. The complete amino acid and nucleic acid sequences for the variable heavy chain region and variable light chain region of the antibodies listed in Table 1 are provided below.

[00147] Variable region of the heavy chain - Parental Ab1 QIQLVQSGGGVVQPGRSLRLSCAASGFTFSSYGMHWVRQAPGKGLEWVAVISYDGSNKY YADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARDLLVRFLEWSHYYGMDVWGQ GTTVTVSS (Seq. ID No.: 24) CAGATCCAGCTGGTGCAGTCTGGGGGAGGCGTGGTCCAGCCTGGGAGGTCCCTGAGACT CTCCTGTGCAGCGTCTGGATTCACCTTCAGTAGCTATGGCATGCACTGGGTCCGCCAGG CTCCAGGCAAGGGGCTGGAGTGGGTGGCAGTTATATCATATGATGGAAGTAATAAATAC TATGCAGACTCCGTGAAGGGCCGATTCACCATCTCCAGAGACAATTCCAAGAACACGCT GTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCTGTGTATTACTGTGCGAGAG ATCTCCTGGTGCGATTTTTGGAGTGGTCGCACTACTACGGTATGGACGTCTGGGGCCAA GGGACCACGGTCACCGTCTCCTCA (SEQ ID NO: 38)

[00148] Heavy chain variable region - germ lineage of Ab2 QVQLVESGGGVVQPGRSLRLSCAASGFTFSSYGMHWVRQAPGKGLEWVAVISYDGSNKY YADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYCARDSHLLVYGWSSTVQY (ID. DE SEQ. N°: 25) CAGGTGCAGCTGGTGGAGTCTGGGGGAGGCGTGGTCCAGCCCTGGGAGGTCCCTGAGACT CTCCTGTGCAGCGTCTGGATTCACCTTCAGTAGCTATGGCATGCACTGGGTCCGCCAGG CTCCAGGCAAGGGGCTGGAGTGGGTGGCAGTTATATCATATTAGGGATTAGTAG TATGCAGACTCCGTGAAGGGCCGATTCACCATCTCCAGAGAGACAATTCCAAGAACACGCT GTATCTGCAAATGAACAGCCCTGAGAGCCGAGGACACGGCTGTGTATTACTGTGCGAGAG ATCTCCTGGTGCGATTTTTGGAGTGGTCGCACTACTACGGTATGGACGCTGGGGCCGACCGAGCCGAGCACTACGGTATGGACGCTGGGGCCGACCGAGCCGAGGCCGAGGTCGAGCTGAGCTGAGGCTGCTGGAGGGAGGTCGAGGAGGTCGAGGAGGTCGAGCTGAGCTGAGGAGCTGAGAGACACGCT SEQ No: 39)

[00149] Heavy chain variable region - parental Ab3 Petition 870210013044, of 08 / 02 / 2021, p. 67 / 205 58 / 190 QIQLVQSGGGVVQPGRSLRLSCAASGFAFSSYGMHWVRQAPGKGLEWVAVISYDGSIKY YADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARDLLVRFLEWSHKYGMDVWGQ GTTVTVSS (ID. DE SEQ. N°: 26) CAGATCCAGCTGGTGCAGTCTGGGGGAGGCGTGGTCCAGCCTGGGAGGTCCCTGAGACT CTCCTGTGCAGCGTCTGGATTCGCCTTCAGTAGCTATGGCATGCACTGGGTCCGCCAGG CTCCAGGCAAGGGGCTGGAGTGGGTGGCAGTTATATCATATGATGGAAGTATCAAATAC TATGCAGACTCCGTGAAGGGCCGATTCACCATCTCCAGAGACAATTCCAAGAACACGCT GTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCTGTGTATTACTGTGCGAGAG ATCTCCTGGTGCGATTTTTGGAGTGGTCGCACAAGTACGGTATGGACGTCTGGGGCCAA GGGACCACGGTCACCGTCTCCTCA (ID. DE SEQ. N°: 40)

[00150] Região variável da cadeia pesada - linhagem germinativa de Ab4 QVQLVESGGGVVQPGRSLRLSCAASGFAFSSYGMHWVRQAPGKGLEWVAVISYDGSIKY YADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARDLLVRFLEWSHKYGMDVWGQ GTTVTVSS (ID. DE SEQ. N°: 27) CAGGTGCAGCTGGTGGAGTCTGGGGGAGGCGTGGTCCAGCCCTGGGAGGTCCCTGAGACT CTCCTGTGCAGCGTCTGGATTCGCCTTCAGTAGCTATGGCATGCACTGGGTCCGCCAGG CTCCAGGCAAGGGGCTGGAGTGGGTGGCAGTTATATC TATGCAGACTCCGTGAAGGGCCGATTCACCATCTCCAGAGAGACAATTCCAAGAACACGCT GTATCTGCAAATGAACAGCCCTGAGAGCCGAGGACACGGCTGTGTATTACTGTGCGAGAG ATCTCCTGGTGCGATTTTTGGAGTGGTCGCAAGTACGGTATGGACGCTGGGGCCAAGAGGCCCAAGTACGGTATGGACGTCTGGGGCCAAGAGGCCGAGTCCAAGTACGGAGAG SEQ No: 41)

[00151] Heavy Chain Variable Region - Ab5 Parental QIQLVQSGGGVVQPGRSLRLSCAASGFAFSSYGMHWVRQAPGKGLEWVAVISYDGNNKY YADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYCARDLLVRFLESHGWSSQYGWGTVTV. SEQ No: 28) CAGATCCAGCTGGTGCAGTCTGGGGGAGGCGTGGTCCAGCCCTGGGAGGTCCCTGAGACT CTCCTGTGCAGCGTCTGGATTCGCCTTCAGTAGCTATGGCATGCACTGGGTCCGCCAGG CTCCAGGCAAGGGGCTGGAGTGGGTGGCAGTTATATCATATATAGGGATA TATGCAGACTCCGTGAAGGGCCGATTCACCATCTCCAGAGACAATTCCAAGAACACGCT Petition 870210013044, of 08 / 02 / 2021, p. 68 / 205 58 / 190 QIQLVQSGGGVVQPGRSLRLSCAASGFAFSSYGMHWVRQAPGKGLEWVAVISYDGSIKY YADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARDLLVRFLEWSHKYGMDVWGQ GTTVTVSS (ID. DE SEQ. N°: 26) CAGATCCAGCTGGTGCAGTCTGGGGGAGGCGTGGTCCAGCCTGGGAGGTCCCTGAGACT CTCCTGTGCAGCGTCTGGATTCGCCTTCAGTAGCTATGGCATGCACTGGGTCCGCCAGG CTCCAGGCAAGGGGCTGGAGTGGGTGGCAGTTATATCATATGATGGAAGTATCAAATAC TATGCAGACTCCGTGAAGGGCCGATTCACCATCTCCAGAGACAATTCCAAGAACACGCT GTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCTGTGTATTACTGTGCGAGAG ATCTCCTGGTGCGATTTTTGGAGTGGTCGCACAAGTACGGTATGGACGTCTGGGGCCAA GGGACCACGGTCACCGTCTCCTCA (ID. DE SEQ. N°: 40)

[00150] Região variável da cadeia pesada - linhagem germinativa de Ab4 QVQLVESGGGVVQPGRSLRLSCAASGFAFSSYGMHWVRQAPGKGLEWVAVISYDGSIKY YADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARDLLVRFLEWSHKYGMDVWGQ GTTVTVSS (ID. DE SEQ. N°: 27) CAGGTGCAGCTGGTGGAGTCTGGGGGAGGCGTGGTCCAGCCCTGGGAGGTCCCTGAGACT CTCCTGTGCAGCGTCTGGATTCGCCTTCAGTAGCTATGGCATGCACTGGGTCCGCCAGG CTCCAGGCAAGGGGCTGGAGTGGGTGGCAGTTATATC TATGCAGACTCCGTGAAGGGCCGATTCACCATCTCCAGAGAGACAATTCCAAGAACACGCT GTATCTGCAAATGAACAGCCCTGAGAGCCGAGGACACGGCTGTGTATTACTGTGCGAGAG ATCTCCTGGTGCGATTTTTGGAGTGGTCGCAAGTACGGTATGGACGCTGGGGCCAAGAGGCCCAAGTACGGTATGGACGTCTGGGGCCAAGAGGCCGAGTCCAAGTACGGAGAG SEQ No: 41)

[00151] Heavy Chain Variable Region - Ab5 Parental QIQLVQSGGGVVQPGRSLRLSCAASGFAFSSYGMHWVRQAPGKGLEWVAVISYDGNNKY YADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYCARDLLVRFLESHGWSSQYGWGTVTV. SEQ No: 28) CAGATCCAGCTGGTGCAGTCTGGGGGAGGCGTGGTCCAGCCCTGGGAGGTCCCTGAGACT CTCCTGTGCAGCGTCTGGATTCGCCTTCAGTAGCTATGGCATGCACTGGGTCCGCCAGG CTCCAGGCAAGGGGCTGGAGTGGGTGGCAGTTATATCATATATAGGGATA TATGCAGACTCCGTGAAGGGCCGATTCACCATCTCCAGAGACAATTCCAAGAACACGCT Petition 870210013044, of 08 / 02 / 2021, p. 68 / 205 59 / 190 GTATCTGCAAATGAACAGCCCTGAGAGCCGAGGACACGGCTGTGTATTACTGTGCGAGAG ATCTCCTGGTGCGATTTTTGGAGTGGTCGCACAAGTACGGTATGGACGTCTGGGGCCAA GGGACCACGGTCACCGTCTCCTCCA (ID. DE SEQ. N°: 42)

[00152] Heavy chain variable region - germ lineage of Ab6 QVQLVESGGGVVQPGRSLRLSCAASGFAFSSYGMHWVRQAPGKGLEWVAVISYDGNNKY YADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYCARDSHRFKVGWSSTVGWGTVLLV (ID. DE SEQ. N°: 29) CAGGTGCAGCTGGTGGAGTCTGGGGGAGGCGTGGTCCAGCCCTGGGAGGTCCCTGAGACT CTCCTGTGCAGCGTCTGGATTCGCCTTCAGTAGCTATGGCATGGCACTGGGTCCGCCAGG CTCCAGGCAAGGGGCTGGAGTGGGTGGCAGTTATATCATATAGGGGATT TATGCAGACTCCGTGAAGGGCCGATTCACCATCTCCAGAGAGACAATTCCAAGAACACGCT GTATCTGCAAATGAACAGCCCTGAGAGCCGAGGACACGGCTGTGTATTACTGTGCGAGAG ATCTCCTGGTGCGATTTTTGGAGTGGTCGCAAGTACGGTATGGACGCTGGGGCCAAGAGGCCCAAGTACGGTATGGACGTCTGGGGCCAAGAGGCCGAGTCCAAGTACGGAGAG SEQ No: 43)

[00153] Light Chain Variable Region - Ab1 Parental QPVLTQPPSASGTPGQRVTISCSGSSSNIGSNTVHYQQLPGTAPKLLIYSDNQRPSGV PDRFSGSKSGTSASLVISGLQSDDEADYYCAAWDDSLNGVFGGGTKLTVL (ID. DE: N°Q. 30) CAGCCTGTGCTGACTCAGCCACCCTCAGCGTCTGGGACCCCCGGGCAGAGGGTCACCAT CTCTTGTTCTGGAAGCAGCTCCAACATCGGAAGTAATACTGTCCACTGGTACCAGCAAC TCCCAGGAACGGCCCCCAAACTCCTCATCTATAGTGATAATCAGCGCCCCTCAGGGGTCAT CCTGACCGATTCTCTGGCTCCAAGTCTGGCACCTCAGCCTCCCTGGTCATCAGTGGGCT CCAGTCTGACGATGAGGCTGATTATTACTGTGCAGCATGGGATGACAGCCTGAATGGGG TGTTCCGGCGGAGGGACCAAGCTGACCGTCCTA (ID. DE SEQ. N°: 44)

[00154] Ab2 Light Chain - Germline Variable Region QSVLTQPPSASGTPGQRVTISCSGSSSNIGSNTVHWYQLPGTAPKLLIYSDNQRPSGV PDRFSGSKSGTSLAISGLQSEDEADYCAAWDDSLNGVGGGTKLTVQL DEADYYCAAWDDSLNGVGGGTKLTVQL (ID: N. SE: N°31) Petition 870210013044, of 08 / 02 / 2021, p. 69 / 205 59 / 190 GTATCTGCAAATGAACAGCCCTGAGAGCCGAGGACACGGCTGTGTATTACTGTGCGAGAG ATCTCCTGGTGCGATTTTTGGAGTGGTCGCACAAGTACGGTATGGACGTCTGGGGCCAA GGGACCACGGTCACCGTCTCCTCCA (ID. DE SEQ. N°: 42)

[00152] Heavy chain variable region - germ lineage of Ab6 QVQLVESGGGVVQPGRSLRLSCAASGFAFSSYGMHWVRQAPGKGLEWVAVISYDGNNKY YADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYCARDSHRFKVGWSSTVGWGTVLLV (ID. DE SEQ. N°: 29) CAGGTGCAGCTGGTGGAGTCTGGGGGAGGCGTGGTCCAGCCCTGGGAGGTCCCTGAGACT CTCCTGTGCAGCGTCTGGATTCGCCTTCAGTAGCTATGGCATGGCACTGGGTCCGCCAGG CTCCAGGCAAGGGGCTGGAGTGGGTGGCAGTTATATCATATAGGGGATT TATGCAGACTCCGTGAAGGGCCGATTCACCATCTCCAGAGAGACAATTCCAAGAACACGCT GTATCTGCAAATGAACAGCCCTGAGAGCCGAGGACACGGCTGTGTATTACTGTGCGAGAG ATCTCCTGGTGCGATTTTTGGAGTGGTCGCAAGTACGGTATGGACGCTGGGGCCAAGAGGCCCAAGTACGGTATGGACGTCTGGGGCCAAGAGGCCGAGTCCAAGTACGGAGAG SEQ No: 43)

[00153] Light Chain Variable Region - Ab1 Parental QPVLTQPPSASGTPGQRVTISCSGSSSNIGSNTVHYQQLPGTAPKLLIYSDNQRPSGV PDRFSGSKSGTSASLVISGLQSDDEADYYCAAWDDSLNGVFGGGTKLTVL (ID. DE: N°Q. 30) CAGCCTGTGCTGACTCAGCCACCCTCAGCGTCTGGGACCCCCGGGCAGAGGGTCACCAT CTCTTGTTCTGGAAGCAGCTCCAACATCGGAAGTAATACTGTCCACTGGTACCAGCAAC TCCCAGGAACGGCCCCCAAACTCCTCATCTATAGTGATAATCAGCGCCCCTCAGGGGTCAT CCTGACCGATTCTCTGGCTCCAAGTCTGGCACCTCAGCCTCCCTGGTCATCAGTGGGCT CCAGTCTGACGATGAGGCTGATTATTACTGTGCAGCATGGGATGACAGCCTGAATGGGG TGTTCCGGCGGAGGGACCAAGCTGACCGTCCTA (ID. DE SEQ. N°: 44)

[00154] Ab2 Light Chain - Germline Variable Region QSVLTQPPSASGTPGQRVTISCSGSSSNIGSNTVHWYQLPGTAPKLLIYSDNQRPSGV PDRFSGSKSGTSLAISGLQSEDEADYCAAWDDSLNGVGGGTKLTVQL DEADYYCAAWDDSLNGVGGGTKLTVQL (ID: N. SE: N°31) Petition 870210013044, of 08 / 02 / 2021, p. 69 / 205 60 / 190 CAGTCTGTGCTGACTCAGCCACCCTCAGCGTCTGGGACCCCCGGGCAGAGGGTCACCAT CTCTTGTTCTGGAAGCAGCTCCAACATCGGAAGTAATACTGTCCACTGGTACCAGCAAC TCCCAGGAACGGCCCCCAAACTCCTCATCTATAGTGATAATCAGCGCCCCTCAGGGGTC CCTGACCGATTCTCTGGCTCCAAGTCTGGCACCTCAGCCTCCCTGGCCATCAGTGGGCT CCAGTCTGAGGATGAGGCTGATTATTACTGTGCAGCATGGGATGACAGCCTGAATGGGG TGTTCGGCGGAGGGACCAAGCTGACCGTCCTA (ID. DE SEQ. N°: 45)

[00155] Região variável da cadeia leve - Ab3 parental QPVLTQPPSASGTPGQRVTISCSGSTSNIGSNTVHWYQQLPGTAPKLLIYSDDQRPSGV PDRFSGSKSGTSASLVISGLQSDDEADYYCAAWDESLNGVFGGGTKLTVL (ID. DE SEQ. N°: 32) CAGCCTGTGCTGACTCAGCCACCCTCAGCGTCTGGGACCCCCGGGCAGAGGGTCACCAT CTCTTGTTCTGGAAGCACCTCCAACATCGGAAGTAATACTGTCCACTGGTACCAGCAAC TCCCAGGAACGGCCCCCAAACTCCTCATCTATAGTGATGATCAGCGCCCCTCAGGGGTC CCTGACCGATTCTCTGGCTCCAAGTCTGGCACCTCAGCCTCCCTGGTCATCAGTGGGCT CCAGTCTGACGATGAGGCTGATTATTACTGTGCAGCATGGGATGAGAGCCTGAATGGGG TGTTCGGCGGAGGGACCAAGCTGACCGTCCTA (ID. DE SEQ. N°: 46)

[00156] Light chain variable region - germ lineage of Ab4 QSVLTQPPSASGTPGQRVTISCSGSTSNIGSNTVHWYQLPGTAPKLLIYSDDQRPSGV PDRFSGSKSGTSASLAISGLQSEDEADYCAAWDESLNGVGGGTKLTVL DEADYYCAAWDESLNGVGGGTKLTVQL (ID: NO. SEQ33) CAGTCTGTGCTGACTCAGCCACCCTCAGCGTCTGGGACCCCCGGGCAGAGGGTCACCAT CTCTTGTTCTGGAAGCACCTCCAACATCGGAAGTAATACTGTCCACTGGTACCAGCAAC TCCCAGGAACGGCCCCCAAACTCCTCATCTATAGTGATCAGCGCCCCTCAGGGGTCAT CCTGACCGATTCTCTGGCTCCAAGTCTGGCACCTCAGCCTCCCTGGCCATCAGTGGGCT CCAGTCTGAGGATGAGGCTGATTATTACTGCAGCATGGGATGAGAGCCTGAATGGGG TGTTCCGGCGGAGGGACCAAGCTGACCGTCCTA (DE SEQ. ID: N° 47)

[00157] Light chain variable region - Ab5 parental QPVLTQPPSASGTPGQRVTISCSGSSSNIGGNTWHWYQQLPGTAPKLLIYSDDQRPSGV PDRFSGSKSGTSASLVISGLQSDDEADYYCAAWDESLNGVFGGGTKLTVL (ID. Petition 870210013044, of 08 / 02 / 2021, p. 70 / 205 60 / 190 CAGTCTGTGCTGACTCAGCCACCCTCAGCGTCTGGGACCCCCGGGCAGAGGGTCACCAT CTCTTGTTCTGGAAGCAGCTCCAACATCGGAAGTAATACTGTCCACTGGTACCAGCAAC TCCCAGGAACGGCCCCCAAACTCCTCATCTATAGTGATAATCAGCGCCCCTCAGGGGTC CCTGACCGATTCTCTGGCTCCAAGTCTGGCACCTCAGCCTCCCTGGCCATCAGTGGGCT CCAGTCTGAGGATGAGGCTGATTATTACTGTGCAGCATGGGATGACAGCCTGAATGGGG TGTTCGGCGGAGGGACCAAGCTGACCGTCCTA (ID. DE SEQ. N°: 45)

[00155] Região variável da cadeia leve - Ab3 parental QPVLTQPPSASGTPGQRVTISCSGSTSNIGSNTVHWYQQLPGTAPKLLIYSDDQRPSGV PDRFSGSKSGTSASLVISGLQSDDEADYYCAAWDESLNGVFGGGTKLTVL (ID. DE SEQ. N°: 32) CAGCCTGTGCTGACTCAGCCACCCTCAGCGTCTGGGACCCCCGGGCAGAGGGTCACCAT CTCTTGTTCTGGAAGCACCTCCAACATCGGAAGTAATACTGTCCACTGGTACCAGCAAC TCCCAGGAACGGCCCCCAAACTCCTCATCTATAGTGATGATCAGCGCCCCTCAGGGGTC CCTGACCGATTCTCTGGCTCCAAGTCTGGCACCTCAGCCTCCCTGGTCATCAGTGGGCT CCAGTCTGACGATGAGGCTGATTATTACTGTGCAGCATGGGATGAGAGCCTGAATGGGG TGTTCGGCGGAGGGACCAAGCTGACCGTCCTA (ID. DE SEQ. N°: 46)

[00156] Light chain variable region - germ lineage of Ab4 QSVLTQPPSASGTPGQRVTISCSGSTSNIGSNTVHWYQLPGTAPKLLIYSDDQRPSGV PDRFSGSKSGTSASLAISGLQSEDEADYCAAWDESLNGVGGGTKLTVL DEADYYCAAWDESLNGVGGGTKLTVQL (ID: NO. SEQ33) CAGTCTGTGCTGACTCAGCCACCCTCAGCGTCTGGGACCCCCGGGCAGAGGGTCACCAT CTCTTGTTCTGGAAGCACCTCCAACATCGGAAGTAATACTGTCCACTGGTACCAGCAAC TCCCAGGAACGGCCCCCAAACTCCTCATCTATAGTGATCAGCGCCCCTCAGGGGTCAT CCTGACCGATTCTCTGGCTCCAAGTCTGGCACCTCAGCCTCCCTGGCCATCAGTGGGCT CCAGTCTGAGGATGAGGCTGATTATTACTGCAGCATGGGATGAGAGCCTGAATGGGG TGTTCCGGCGGAGGGACCAAGCTGACCGTCCTA (DE SEQ. ID: N° 47)

[00157] Light chain variable region - Ab5 parental QPVLTQPPSASGTPGQRVTISCSGSSSNIGGNTWHWYQQLPGTAPKLLIYSDDQRPSGV PDRFSGSKSGTSASLVISGLQSDDEADYYCAAWDESLNGVFGGGTKLTVL (ID. Petition 870210013044, of 08 / 02 / 2021, p. 70 / 205 61 / 190 SEQ. No: 34) CAGCCTGTGCTGACTCAGCCACCCTCAGCGTCTGGGACCCCCGGGCAGAGGGTCACCAT CTCTTGTTCTGGAAGCAGCTCCAACATCGGAGGAAATACTGTCCACTGGTACCAGCAAC TCCCAGGAACGGCCCCCAAACTCCTCATCTATAGTGATGATCAGCGCCCCTCAGGGGTC CCTGACCGATTCTCTGGCTCCAAGTCTGGCACCTCAGCCTCCCTGGTCATCAGTGGGCT CCAGTCTGACGATGAGGCTGATTATTACTGTGCAGCATGGGATGAGAGCCTGAATGGGG TGTTCGGCGGAGGGACCAAGCTGACCGTCCTA (ID. DE SEQ. N°: 48)

[00158] Região variável da cadeia leve - linhagem germinativa de Ab6 QSVLTQPPSASGTPGQRVTISCSGSSSNIGGNTVHWYQQLPGTAPKLLIYSDDQRPSGV PDRFSGSKSGTSASLAISGLQSEDEADYYCAAWDESLNGVFGGGTKLTVL (ID. DE SEQ. N°: 35) CAGTCTGTGCTGACTCAGCCACCCTCAGCGTCTGGGACCCCCGGGCAGAGGGTCACCAT CTCTTGTTCTGGAAGCAGCTCCAACATCGGAGGAAATACTGTCCACTGGTACCAGCAAC TCCCAGGAACGGCCCCCAAACTCCTCATCTATAGTGATGATCAGCGCCCCTCAGGGGTC CCTGACCGATTCTCTGGCTCCAAGTCTGGCACCTCAGCCTCCCTGGCCATCAGTGGGCT CCAGTCTGAGGATGAGGCTGATTATTACTGTGCAGCATGGGATGAGAGCCTGAATGGGG TGTTCGGCGGAGGGACCAAGCTGACCGTCCTA (ID. DE SEQ. N°: 49)

[00159] Ab2-Cadeia Pesada QVQLVESGGGVVQPGRSLRLSCAASGFTFSSYGMHWVRQAPGKGLEWVAVISYDGSNKY YADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARDLLVRFLEWSHYYGMDVWGQ GTTVTVSSASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVH TFPAVLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCP APEFLGGPSVFLFPPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKT KPREEQFNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQV YTLPPSQEEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLY SRLTVDKSRWQEGNVFSCSVMHEALHNHYTQKSLSLSLG (ID. DE SEQ. N°: 50)

[00160] Ab2-Cadeia live QSVLTQPPSASGTPGQRVTISCSGSSSNIGSNTVHWYQQLPGTAPKLLIYSDNQRPSGV PDRFSGSKSGTSASLAISGLQSEDEADYYCAAWDDSLNGVFGGGTKLTVLGQPKAAPSV Petition 870210013044, de 08 / 02 / 2021, pág. 71 / 205 61 / 190 SEQ. N°: 34) CAGCCTGTGCTGACTCAGCCACCCTCAGCGTCTGGGACCCCCGGGCAGAGGGTCACCAT CTCTTGTTCTGGAAGCAGCTCCAACATCGGAGGAAATACTGTCCACTGGTACCAGCAAC TCCCAGGAACGGCCCCCAAACTCCTCATCTATAGTGATGATCAGCGCCCCTCAGGGGTC CCTGACCGATTCTCTGGCTCCAAGTCTGGCACCTCAGCCTCCCTGGTCATCAGTGGGCT CCAGTCTGACGATGAGGCTGATTATTACTGTGCAGCATGGGATGAGAGCCTGAATGGGG TGTTCGGCGGAGGGACCAAGCTGACCGTCCTA (ID. DE SEQ. N°: 48)

[00158] Região variável da cadeia leve - linhagem germinativa de Ab6 QSVLTQPPSASGTPGQRVTISCSGSSSNIGGNTVHWYQQLPGTAPKLLIYSDDQRPSGV PDRFSGSKSGTSASLAISGLQSEDEADYYCAAWDESLNGVFGGGTKLTVL (ID. DE SEQ. N°: 35) CAGTCTGTGCTGACTCAGCCACCCTCAGCGTCTGGGACCCCCGGGCAGAGGGTCACCAT CTCTTGTTCTGGAAGCAGCTCCAACATCGGAGGAAATACTGTCCACTGGTACCAGCAAC TCCCAGGAACGGCCCCCAAACTCCTCATCTATAGTGATGATCAGCGCCCCTCAGGGGTC CCTGACCGATTCTCTGGCTCCAAGTCTGGCACCTCAGCCTCCCTGGCCATCAGTGGGCT CCAGTCTGAGGATGAGGCTGATTATTACTGTGCAGCATGGGATGAGAGCCTGAATGGGG TGTTCGGCGGAGGGACCAAGCTGACCGTCCTA (ID. DE SEQ. N°: 49)

[00159] Ab2-Cadeia Pesada QVQLVESGGGVVQPGRSLRLSCAASGFTFSSYGMHWVRQAPGKGLEWVAVISYDGSNKY YADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARDLLVRFLEWSHYYGMDVWGQ GTTVTVSSASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVH TFPAVLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCP APEFLGGPSVFLFPPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKT KPREEQFNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQV YTLPPSQEEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLY SRLTVDKSRWQEGNVFSCSVMHEALHNHYTQKSLSLSLG (ID. DE SEQ. N°: 50)

[00160] Ab2-Cadeia live QSVLTQPPSASGTPGQRVTISCSGSSSNIGSNTVHWYQQLPGTAPKLLIYSDNQRPSGV PDRFSGSKSGTSASLAISGLQSEDEADYYCAAWDDSLNGVFGGGTKLTVLGQPKAAPSV Petition 870210013044, de 08 / 02 / 2021, pág. 71 / 205 62 / 190 TLFPPSSEELQANKATLVCLISDFYPGAVTVAWKADSSPVKAGVETTTPSKQSNNKYAA SSYLSLTPEQWKSHRSYSCQVTHEGSTVEKTVAPTECS (ID. DE SEQ. N°: 51)

[00161] In some embodiments, anti-promyostatin / latent myostatin development antibodies include any antibody that includes a variable heavy chain domain of any of the IDS. SEQ. Nos: 24-29 or a variable light chain domain of any of the IDS. SEQ. Nos: 30-35. In some embodiments, anti-promyostatin / latent myostatin development antibodies include any antibody that includes both variable heavy chain and variable light chain pairs of the IDS. SEQ. Nos: 24 and 30; 25 and 31; 26 and 32; 27 and 33; 28 and 34; or 29 and 35).

[00162] Aspects of the disclosure provide anti-promyostatin / latent myostatin antibodies that possess a variable heavy chain amino acid sequence and / or a variable light chain amino acid sequence homologous to any of those described in this descriptive report. In some embodiments, the anti-promyostatin / latent myostatin antibody comprises a variable heavy chain sequence or a variable light chain sequence that is at least 75% (e.g., 80%, 85%, 90%, 95%, 98%, or 99%) identical to the variable heavy chain sequence of any of the IDS. DE SEQ. Nos: 24-29 or a variable light chain sequence of any of the IDS. DE SEQ. Nos: 30-35. In some embodiments, the homologous variable heavy chain and / or variable light chain amino acid sequences do not vary within any of the CDR sequences provided in this descriptive report.For example, in some modalities, the degree of sequence variation (e.g., 75%, 80%, 85%, 90%, 95%, 98% or 99%). Petition 870210013044, dated 08 / 02 / 2021, p. 72 / 205 62 / 190 TLFPPSSEELQANKATLVCLISDFYPGAVTVAWKADSSPVKAGVETTTPSKQSNNKYAA SSYLSLTPEQWKSHRSYSCQVTHEGSTVEKTVAPTECS (SEQ ID NO: 51)

[00161] In some embodiments, anti-promyostatin / latent myostatin development antibodies include any antibody that includes a variable heavy chain domain of any of the IDS. SEQ. Nos: 24-29 or a variable light chain domain of any of the IDS. SEQ. Nos: 30-35. In some embodiments, anti-promyostatin / latent myostatin development antibodies include any antibody that includes both variable heavy chain and variable light chain pairs of the IDS. SEQ. Nos: 24 and 30; 25 and 31; 26 and 32; 27 and 33; 28 and 34; or 29 and 35).

[00162] Aspects of the disclosure provide anti-promyostatin / latent myostatin antibodies that possess a variable heavy chain amino acid sequence and / or a variable light chain amino acid sequence homologous to any of those described in this descriptive report. In some embodiments, the anti-promyostatin / latent myostatin antibody comprises a variable heavy chain sequence or a variable light chain sequence that is at least 75% (e.g., 80%, 85%, 90%, 95%, 98%, or 99%) identical to the variable heavy chain sequence of any of the IDS. DE SEQ. Nos: 24-29 or a variable light chain sequence of any of the IDS. DE SEQ. Nos: 30-35. In some embodiments, the homologous variable heavy chain and / or variable light chain amino acid sequences do not vary within any of the CDR sequences provided in this descriptive report.For example, in some modalities, the degree of sequence variation (e.g., 75%, 80%, 85%, 90%, 95%, 98% or 99%). Petition 870210013044, dated 08 / 02 / 2021, page 72 / 205 63 / 190 may occur within a variable heavy chain sequence and / or a variable light chain sequence, excluding any of the CDR sequences provided in this descriptive report.

[00163] The “percent identity of two amino acid sequences is determined using the algorithm of Karlin and Altschul Proc. Natl. Acad. Sci. USA 87: 2264-68, 1990, modified as in Karlin and Altschul Proc. Natl. Acad. Sci. USA 90: 5873-77, 1993. An algorithm of this type is incorporated into the NBLAST and XBLAST (version 2.0) programs of Altschul et al., J. Mol. Biol. 215: 403-10, 1990. Protein searches in BLAST can be performed with the XBLAST program, score = 50, word length = 3 to obtain amino acid sequences homologous to the protein molecules of interest. When gaps exist between two sequences, “Gapped BLAST” can be used as described in Altschul et al. Nucleic Acids Res. 25 (17): 3.389-3.402, 1997. When using the BLAST and Gapped BLAST programs, the default parameters of the respective programs (e.g., XBLAST and NBLAST) can be used.

[00164] In some embodiments, conservative mutations can be introduced into CDR or scaffold sequences at positions where residues are unlikely to be involved in the interaction with promyostatin / latent myostatin, as determined based on crystal structure. As used in this report, a “conservative amino acid substitution” refers to an amino acid substitution that does not alter the relative charge or size characteristics of the protein in which the amino acid substitution is made. Variants can be prepared according to methods for Petition 870210013044, dated 08 / 02 / 2021, p. 73 / 205 63 / 190 may occur within a variable heavy chain sequence and / or a variable light chain sequence, excluding any of the CDR sequences provided in this descriptive report.

[00163] The “percent identity of two amino acid sequences is determined using the algorithm of Karlin and Altschul Proc. Natl. Acad. Sci. USA 87: 2264-68, 1990, modified as in Karlin and Altschul Proc. Natl. Acad. Sci. USA 90: 5873-77, 1993. An algorithm of this type is incorporated into the NBLAST and XBLAST (version 2.0) programs of Altschul et al., J. Mol. Biol. 215: 403-10, 1990. Protein searches in BLAST can be performed with the XBLAST program, score = 50, word length = 3 to obtain amino acid sequences homologous to the protein molecules of interest. When gaps exist between two sequences, “Gapped BLAST” can be used as described in Altschul et al. Nucleic Acids Res. 25 (17): 3.389-3.402, 1997. When using the BLAST and Gapped BLAST programs, the default parameters of the respective programs (e.g., XBLAST and NBLAST) can be used.

[00164] In some embodiments, conservative mutations can be introduced into CDR or scaffold sequences at positions where residues are unlikely to be involved in the interaction with promyostatin / latent myostatin, as determined based on crystal structure. As used in this report, a “conservative amino acid substitution” refers to an amino acid substitution that does not alter the relative charge or size characteristics of the protein in which the amino acid substitution is made. Variants can be prepared according to methods for Petition 870210013044, dated 08 / 02 / 2021, p. 73 / 205 64 / 190 alteration of the sequence of polypeptides known to those skilled in the art, such as those found in references that compile these methods, for example, “Molecular Cloning: A Laboratory Manual”, J. Sambrook, et al., eds., Second Edition, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York, 1989, or “Current Protocols in Molecular Biology”, FM Ausubel, et al., eds., John Wiley & Sons, Inc., New York. Conservative amino acid substitutions include substitutions made between amino acids within the following groups: (a) M, I, L, V; (b) F, Y, W; (c) K, R, H; (d) A, G; (e) S, T; (f) Q, N; and (g) E, D.

[00165] In some embodiments, the antibodies provided in this descriptive report comprise mutations that confer desirable properties to the antibodies. For example, to avoid potential complications due to Fab-arm switching, which is known to occur with native IgG4 mAbs, the antibodies provided in this descriptive report may comprise a stabilizing ‘Adair’ mutation (Angal S., et al., “A Single Amino Acid Substitution Abolishes the Heterogeneity of the Chimeric Mouse / Human Antibody (IgG4)”, Mol. Immunol. 30, 105-108; 1993), in which serine 228 (numbering of EU; residue 241 in Kabat numbering) is converted to proline resulting in an IgG1-like hinge sequence (CPPCP (ID. DE SEQ. N°: 58)). Consequently, any of the antibodies may include a stabilizing 'Adair' mutation or the CPPCP amino acid sequence (ID. DE SEQ. N°: 58).

[00166] The anti-promyostatin / latent myostatin binding agents of this revelation may Petition 870210013044, dated 08 / 02 / 2021, p. 74 / 205 64 / 190 alteration of the sequence of polypeptides known to those skilled in the art, such as those found in references that compile these methods, for example, “Molecular Cloning: A Laboratory Manual”, J. Sambrook, et al., eds., Second Edition, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York, 1989, or “Current Protocols in Molecular Biology”, FM Ausubel, et al., eds., John Wiley & Sons, Inc., New York. Conservative amino acid substitutions include substitutions made between amino acids within the following groups: (a) M, I, L, V; (b) F, Y, W; (c) K, R, H; (d) A, G; (e) S, T; (f) Q, N; and (g) E, D.

[00165] In some embodiments, the antibodies provided in this descriptive report comprise mutations that confer desirable properties to the antibodies. For example, to avoid potential complications due to Fab-arm switching, which is known to occur with native IgG4 mAbs, the antibodies provided in this descriptive report may comprise a stabilizing ‘Adair’ mutation (Angal S., et al., “A Single Amino Acid Substitution Abolishes the Heterogeneity of the Chimeric Mouse / Human Antibody (IgG4)”, Mol. Immunol. 30, 105-108; 1993), in which serine 228 (numbering of EU; residue 241 in Kabat numbering) is converted to proline resulting in an IgG1-like hinge sequence (CPPCP (ID. DE SEQ. N°: 58)). Consequently, any of the antibodies may include a stabilizing 'Adair' mutation or the CPPCP amino acid sequence (ID. DE SEQ. N°: 58).

[00166] The anti-promyostatin / latent myostatin binding agents of this revelation may Petition 870210013044, dated 08 / 02 / 2021, p. 74 / 205 65 / 190 may optionally comprise antibody constant regions or portions thereof. For example, a Vl domain may be attached at its C-terminal end to a light chain constant domain such as Ck or Cλ. Similarly, a Vh domain or portion thereof may be attached to all or part of a heavy chain such as IgA, IgD, IgE, IgG, and IgM, and any isotype subclass. Antibodies may include suitable constant regions (see, for example, Kabat et al., “Sequences of Proteins of Immunological Interest”, No. 91-3242, “National Institutes of Health Publications”, Bethesda, Md. (1991)). Therefore, antibodies within the scope of this disclosure may include Vh and Vl domains, or an antigen-binding portion thereof, combined with any suitable constant regions.

[00167] In certain embodiments, the Vh and / or Vl domains can be reverted to the germline sequence; for example, the FRs of these domains are mutated using conventional molecular biology techniques to match those produced by germline cells. For example, the Vh and / or Vl domains can be reverted to the germline sequence of IgHV330 (SEQ ID No.: 36) and / or IgLV1-44 (SEQ ID No.: 37), respectively. It should be noted that either of the Vh and / or Vl domains can be reverted to any suitable germline sequence. In other embodiments, the FR sequences remain divergent from the consensus germline sequences.

[00168] IgHV3-30 qvqlvesgggvvqpgrslrlscaasgftfssygmhwvrqapgkglewvavisydgsnky YADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAR (SEQ ID NO: 36) Petition 870210013044, dated 08 / 02 / 2021, p. 75 / 205 65 / 190 may optionally comprise antibody constant regions or portions thereof. For example, a Vl domain may be attached at its C-terminal end to a light chain constant domain such as Ck or Cλ. Similarly, a Vh domain or portion thereof may be attached to all or part of a heavy chain such as IgA, IgD, IgE, IgG, and IgM, and any isotype subclass. Antibodies may include suitable constant regions (see, for example, Kabat et al., “Sequences of Proteins of Immunological Interest”, No. 91-3242, “National Institutes of Health Publications”, Bethesda, Md. (1991)). Therefore, antibodies within the scope of this disclosure may include Vh and Vl domains, or an antigen-binding portion thereof, combined with any suitable constant regions.

[00167] In certain embodiments, the Vh and / or Vl domains can be reverted to the germline sequence; for example, the FRs of these domains are mutated using conventional molecular biology techniques to match those produced by germline cells. For example, the Vh and / or Vl domains can be reverted to the germline sequence of IgHV330 (SEQ ID No.: 36) and / or IgLV1-44 (SEQ ID No.: 37), respectively. It should be noted that either of the Vh and / or Vl domains can be reverted to any suitable germline sequence. In other embodiments, the FR sequences remain divergent from the consensus germline sequences.

[00168] IgHV3-30 qvqlvesgggvvqpgrslrlscaasgftfssygmhwvrqapgkglewvavisydgsnky YADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAR (SEQ ID NO: 36) Petition 870210013044, dated 08 / 02 / 2021, p. 75 / 205 66 / 190

[00169] IgLV1-44 QSVLTQPPSASGTPGQRVTISCSGSSSNIGSNTVNWYQQLPGTAPKLLIYSNNQRPSGV PDRFSGSKSGTSASLAISGLQSEDEADYYCAAWDDSLNG (SEQ ID NO: 37)

[00170] In some embodiments, anti-promyostatin / latent myostatin antibodies or antigen-binding fragments may or may not include the antibody scaffold region shown in IDS. DE SEQ. Nos: 24-35. In some embodiments, anti-promyostatin latent antibodies are murine antibodies and include sequences of the murine scaffold region.

[00171] In some embodiments, anti-promyostatin / latent myostatin antibodies can bind to promyostatin / latent myostatin with relatively high affinity, for example, with a Kd less than 10⁻⁶M, 10⁻⁷M, 10⁻⁸M, 10⁻⁹M, 10⁻¹⁰M, 10⁻¹¹M or less. For example, anti-promyostatin / latent myostatin antibodies can bind to promyostatin / latent myostatin with an affinity between 5 pM and 500 nM, for example, between 50 pM and 100 nM, for example, between 500 pM and 50 nM. The disclosure also includes antibodies or antigen-binding fragments that compete with any of the antibodies described in this descriptive report for binding to latent promiostatin / myostatin and that have an affinity of 50 nM or less (e.g., 20 nM or less, 10 nM or less, 500 pM or less, 50 pM or less, or 5 pM or less).The affinity and binding kinetics of anti-promyostatin / latent myostatin antibody can be tested using any suitable method including, without limitation, biosensor technology (e.g., OCTET or BIACORE).

[00172] An antibody that “binds specifically to a Petition 870210013044, dated 08 / 02 / 2021, p. 76 / 205 66 / 190

[00169] IgLV1-44 QSVLTQPPSASGTPGQRVTISCSGSSSNIGSNTVNWYQQLPGTAPKLLIYSNNQRPSGV PDRFSGSKSGTSASLAISGLQSEDEADYYCAAWDDSLNG (SEQ ID NO: 37)

[00170] In some embodiments, anti-promyostatin / latent myostatin antibodies or antigen-binding fragments may or may not include the antibody scaffold region shown in IDS. DE SEQ. Nos: 24-35. In some embodiments, anti-promyostatin latent antibodies are murine antibodies and include sequences of the murine scaffold region.

[00171] In some embodiments, anti-promyostatin / latent myostatin antibodies can bind to promyostatin / latent myostatin with relatively high affinity, for example, with a Kd less than 10⁻⁶M, 10⁻⁷M, 10⁻⁸M, 10⁻⁹M, 10⁻¹⁰M, 10⁻¹¹M or less. For example, anti-promyostatin / latent myostatin antibodies can bind to promyostatin / latent myostatin with an affinity between 5 pM and 500 nM, for example, between 50 pM and 100 nM, for example, between 500 pM and 50 nM. The disclosure also includes antibodies or antigen-binding fragments that compete with any of the antibodies described in this descriptive report for binding to latent promiostatin / myostatin and that have an affinity of 50 nM or less (e.g., 20 nM or less, 10 nM or less, 500 pM or less, 50 pM or less, or 5 pM or less).The affinity and binding kinetics of anti-promyostatin / latent myostatin antibody can be tested using any suitable method including, without limitation, biosensor technology (e.g., OCTET or BIACORE).

[00172] An antibody that “binds specifically to a Petition 870210013044, dated 08 / 02 / 2021, page 76 / 205 67 / 190 target antigen, binds to the target antigen with greater affinity, avidity, more rapidly and / or for a longer duration than if it binds to non-target antigens. In some embodiments, antibodies that bind specifically to promyostatin / latent myostatin are disclosed in this descriptive report. In some embodiments, any of the antibodies provided in this descriptive report binds to or near a toloid cleavage site or to or near a toloid anchoring site of promyostatin / latent myostatin. In some embodiments, an antibody binds near a toloid cleavage site or near a toloid anchoring site if it binds within 15 or fewer amino acid residues of the toloid cleavage site or toloid anchoring site.In some embodiments, any of the antibodies provided in this descriptive report binds within 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 amino acid residues of a toloid cleavage site or a toloid anchoring site. In some embodiments, an antibody binds to or near a toloid cleavage site of GDF8. For example, an antibody may bind to an amino acid sequence as described in SEQ. ID NO: 62 PKAPPLRELIDQYDVQRDDSSDGSLEDDDYHAT (SEQ. ID NO: 62). In other embodiments, any of the antibodies provided in this descriptive report binds to or near a proprotein convertase cleavage site, or to or near a proprotein convertase docking site of promyostatin / latent myostatin. In some embodiments, an antibody binds near a proprotein convertase cleavage site or near a docking site of... Petition 870210013044, dated 08 / 02 / 2021, p. 77 / 20567 / 190 target antigen, binds to the target antigen with greater affinity, avidity, more rapidly and / or for a longer duration than if it binds to non-target antigens. In some embodiments, antibodies that bind specifically to promyostatin / latent myostatin are disclosed in this descriptive report. In some embodiments, any of the antibodies provided in this descriptive report binds to or near a toloid cleavage site or to or near a toloid anchoring site of promyostatin / latent myostatin. In some embodiments, an antibody binds near a toloid cleavage site or near a toloid anchoring site if it binds within 15 or fewer amino acid residues of the toloid cleavage site or toloid anchoring site.In some embodiments, any of the antibodies provided in this descriptive report binds within 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 amino acid residues of a toloid cleavage site or a toloid anchoring site. In some embodiments, an antibody binds to or near a toloid cleavage site of GDF8. For example, an antibody may bind to an amino acid sequence as described in SEQ. ID NO: 62 PKAPPLRELIDQYDVQRDDSSDGSLEDDDYHAT (SEQ. ID NO: 62). In other embodiments, any of the antibodies provided in this descriptive report binds to or near a proprotein convertase cleavage site, or to or near a proprotein convertase docking site of promyostatin / latent myostatin. In some embodiments, an antibody binds near a proprotein convertase cleavage site or near a docking site of... Petition 870210013044, dated 08 / 02 / 2021, p. 77 / 205 68 / 190 proprotein convertase if it binds within 15 or fewer amino acid residues of the proprotein convertase cleavage site or the proprotein convertase docking site. In some embodiments, any of the antibodies provided in this descriptive report binds within 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 amino acid residues of a proprotein convertase cleavage site or a proprotein convertase docking site. In some embodiments, an antibody binds to or near a proprotein convertase cleavage site of GDF8. For example, an antibody may bind to an amino acid sequence as described in ID. DE SEQ. No.: 63. GLNPFLEVKVTDTPKRSRRDFGLDCDEHSTESRC (SEQ ID No.: 63).

[00173] In one example, the anti-promiostatin / latent myostatin antibodies described in this descriptive report specifically bind to promiostatin / latent myostatin, compared to other forms of myostatin and / or other members of the TGFp family of growth factors. Members of the TGFp family of growth factors include, without limitation, AMH protein, ARTN, BMP10, BMP15, BMP2, BMP3, BMP4, BMP5, BMP6, BMP7, BMP8A, BMP8B, GDF1, GDF10, GDF11, GDF15, GDF2, GDF3, GDF3A, GDF5, GDF6, GDF7, GDF8, GDF9, GDNF, INHA, INHBA, INHBB, INHBC, INHBE, LEFTY1, LEFTY2, NODAL, NRTN, PSPN, TGFpi, TGFp2, and TGFP3. These antibodies can bind to promiostatin / latent myostatin at a much higher affinity compared to other members of the TGF3 growth factor family (e.g., at least 2-fold, 5-fold, 10-fold, 50-fold, 100-fold, 200-fold, 500-fold, or 1,000-fold). Petition 870210013044, dated 08 / 02 / 2021, page 78 / 205 68 / 190 proprotein convertase if it binds within 15 or fewer amino acid residues of the proprotein convertase cleavage site or the proprotein convertase docking site. In some embodiments, any of the antibodies provided in this descriptive report binds within 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 amino acid residues of a proprotein convertase cleavage site or a proprotein convertase docking site. In some embodiments, an antibody binds to or near a proprotein convertase cleavage site of GDF8. For example, an antibody may bind to an amino acid sequence as described in ID. DE SEQ. No.: 63. GLNPFLEVKVTDTPKRSRRDFGLDCDEHSTESRC (SEQ ID No.: 63).

[00173] In one example, the anti-promiostatin / latent myostatin antibodies described in this descriptive report specifically bind to promiostatin / latent myostatin, compared to other forms of myostatin and / or other members of the TGFp family of growth factors. Members of the TGFp family of growth factors include, without limitation, AMH protein, ARTN, BMP10, BMP15, BMP2, BMP3, BMP4, BMP5, BMP6, BMP7, BMP8A, BMP8B, GDF1, GDF10, GDF11, GDF15, GDF2, GDF3, GDF3A, GDF5, GDF6, GDF7, GDF8, GDF9, GDNF, INHA, INHBA, INHBB, INHBC, INHBE, LEFTY1, LEFTY2, NODAL, NRTN, PSPN, TGFpi, TGFp2, and TGFP3. These antibodies can bind to promiostatin / latent myostatin at a much higher affinity compared to other members of the TGF3 growth factor family (e.g., at least 2-fold, 5-fold, 10-fold, 50-fold, 100-fold, 200-fold, 500-fold, or 1,000-fold). Petition 870210013044, dated 08 / 02 / 2021, page 78 / 205 69 / 190 times greater). In some embodiments, these antibodies can bind to promyostatin / latent myostatin with an affinity at least 1,000 times greater compared to other members of the TGFp family of growth factors. In some embodiments, the antibodies provided in this descriptive report can bind to promyostatin / latent myostatin at a much higher affinity compared to one or more forms of GDF11 or mature myostatin (e.g., at least 2 times, 5 times, 10 times, 50 times, 100 times, 200 times, 500 times, or 1,000 times greater). In some embodiments, the antibodies provided in this descriptive report may bind to promyostatin / latent myostatin with an affinity at least 1,000 times greater compared to one or more forms of GDF11 (e.g., pro-GDF11, latent GDF11, or mature GDF11) or mature myostatin.Alternatively, or in addition, the antibodies may exhibit significantly greater inhibitory activity against proteolytic cleavage of promyostatin / latent myostatin (e.g., by a proprotein convertase or toloid protease) when compared with other members of the TGFp family, e.g., pro-GDF11 / latent GDF11 (e.g., at least 2-fold, 5-fold, 10-fold, 50-fold, 100-fold). 200 times, 500 times, 1,000 times larger).

[00174] In some embodiments, antibodies bind to an antigen but cannot effectively clear the antigen from the plasma. Thus, in some embodiments, the concentration of antigen in the plasma can be increased by reducing antigen clearance. However, in some embodiments, the antibodies (e.g., scavenging antibodies) provided in this descriptive report have a Petition 870210013044, dated 08 / 02 / 2021, page 79 / 205 69 / 190 times greater). In some embodiments, these antibodies can bind to promyostatin / latent myostatin with an affinity at least 1,000 times greater compared to other members of the TGFp family of growth factors. In some embodiments, the antibodies provided in this descriptive report can bind to promyostatin / latent myostatin at a much higher affinity compared to one or more forms of GDF11 or mature myostatin (e.g., at least 2 times, 5 times, 10 times, 50 times, 100 times, 200 times, 500 times, or 1,000 times greater). In some embodiments, the antibodies provided in this descriptive report may bind to promyostatin / latent myostatin with an affinity at least 1,000 times greater compared to one or more forms of GDF11 (e.g., pro-GDF11, latent GDF11, or mature GDF11) or mature myostatin.Alternatively, or in addition, the antibodies may exhibit significantly greater inhibitory activity against proteolytic cleavage of promyostatin / latent myostatin (e.g., by a proprotein convertase or toloid protease) when compared with other members of the TGFp family, e.g., pro-GDF11 / latent GDF11 (e.g., at least 2-fold, 5-fold, 10-fold, 50-fold, 100-fold). 200 times, 500 times, 1,000 times larger).

[00174] In some embodiments, antibodies bind to an antigen but cannot effectively clear the antigen from the plasma. Thus, in some embodiments, the concentration of antigen in the plasma can be increased by reducing antigen clearance. However, in some embodiments, the antibodies (e.g., scavenging antibodies) provided in this descriptive report have a Petition 870210013044, dated 08 / 02 / 2021, page 79 / 205 70 / 190 affinity for an antigen that is pH-sensitive. These pH-sensitive antibodies can bind to the antigen in plasma at neutral pH and dissociate from the antigen in the acidic endosome, thereby reducing antibody-mediated antigen accumulation and / or promoting antigen clearance from the plasma.

[00175] Aspects of the disclosure relate to scavenging antibodies. As used in this report, the term “scavenging antibodies” refers to antibodies that possess both pH-sensitive antigen binding and at least a threshold level of binding to the neonatal cell surface Fc receptor (FcRn) at neutral or physiological pH. In some embodiments, scavenging antibodies bind to the neonatal Fc receptor FcRn at neutral pH. For example, scavenging antibodies may bind to FcRn at a pH ranging from 7.0 to 7.6. In some embodiments, scavenging antibodies may bind to an antigen at an antigen-binding site and bind to a cellular FcRn via an Fc portion of the antibody. In some embodiments, scavenging antibodies may then be internalized, releasing antigen into an acidic endosome, which may be degraded.In some modes, a scavenging antibody, no longer bound to the antigen, can then be released (e.g., by exocytosis) by the cell back into the serum.

[00176] In some embodiments, FcRn in vascular endothelia (e.g., of an individual) extends the half-life of a scavenging antibody. In some embodiments, vascular endothelial cells internalize scavenging antibodies, which, in some embodiments, are bound to an antigen such as, for example, myostatin (e.g., pro Petition 870210013044, dated 08 / 02 / 2021, pages 80 / 205 70 / 190 affinity for an antigen that is pH-sensitive. These pH-sensitive antibodies can bind to the antigen in plasma at neutral pH and dissociate from the antigen in the acidic endosome, thereby reducing antibody-mediated antigen accumulation and / or promoting antigen clearance from the plasma.

[00175] Aspects of the disclosure relate to scavenging antibodies. As used in this report, the term “scavenging antibodies” refers to antibodies that possess both pH-sensitive antigen binding and at least a threshold level of binding to the neonatal cell surface Fc receptor (FcRn) at neutral or physiological pH. In some embodiments, scavenging antibodies bind to the neonatal Fc receptor FcRn at neutral pH. For example, scavenging antibodies may bind to FcRn at a pH ranging from 7.0 to 7.6. In some embodiments, scavenging antibodies may bind to an antigen at an antigen-binding site and bind to a cellular FcRn via an Fc portion of the antibody. In some embodiments, scavenging antibodies may then be internalized, releasing antigen into an acidic endosome, which may be degraded.In some modes, a scavenging antibody, no longer bound to the antigen, can then be released (e.g., by exocytosis) by the cell back into the serum.

[00176] In some embodiments, FcRn in vascular endothelia (e.g., of an individual) extends the half-life of a scavenging antibody. In some embodiments, vascular endothelial cells internalize scavenging antibodies, which, in some embodiments, are bound to an antigen such as, for example, myostatin (e.g., pro Petition 870210013044, dated 08 / 02 / 2021, pages 80 / 205 71 / 190 myostatin, latent myostatin, or sensitized myostatin). In some embodiments, a scavenging antibody is recycled back into the bloodstream. In some embodiments, a scavenging antibody has an increased half-life (e.g., in an individual's serum) when compared to its conventional counterpart. In some embodiments, a conventional counterpart of a scavenging antibody refers to the antibody from which the scavenging antibody was derived (e.g., before genetic modification of the Fc portion of the conventional antibody to bind FcRn with higher affinity at pH 7). In some embodiments, a scavenging antibody has a half-life in an individual's serum that is at least 1%, 5%, 10%, 15%, 20%, 25%, 35%, 50%, 75%, 100%, 150%, 200%, or 250% longer compared to its conventional counterpart.

[00177] In some embodiments, an Fc portion of a scavenging antibody binds to FcRn. In some embodiments, the Fc portion of a scavenging antibody binds to FcRn at a pH of 7.4 with a Kd ranging from 10⁻³M to 10⁻⁸M. In some embodiments, a scavenging antibody binds to FcRn at a pH of 7.4 with a Kd ranging from 10⁻³M to 10⁻⁷M, from 10⁻³M to 10⁻⁶M, from 10⁻³M to 10⁻⁵M, from 10⁻³M to 10⁻⁴M, from 10⁻⁴M to 10⁻⁷M, from 10⁻⁴M to 10⁻⁶M, from 10⁻⁴M to 10⁻⁵M, from 10⁻⁵M to 10⁻⁸M, from 10⁻⁵M to 10⁻⁷ ...�M to 10⁻⁸M, from 10⁻⁶M to 10⁻⁷M, or from 10⁻⁷M to 10⁻⁸M. In some embodiments, FcRn binds to the CH2-CH3 hinge region of a scavenging antibody. In some embodiments, FcRn binds to the same region as protein A or protein G. In some embodiments, FcRn binds to a binding site different from FcyRs. In some embodiments, the Petition 870210013044, dated 08 / 02 / 2021, p. 81 / 205 71 / 190 myostatin, latent myostatin, or sensitized myostatin). In some embodiments, a scavenging antibody is recycled back into the bloodstream. In some embodiments, a scavenging antibody has an increased half-life (e.g., in an individual's serum) when compared to its conventional counterpart. In some embodiments, a conventional counterpart of a scavenging antibody refers to the antibody from which the scavenging antibody was derived (e.g., before genetic modification of the Fc portion of the conventional antibody to bind FcRn with higher affinity at pH 7). In some embodiments, a scavenging antibody has a half-life in an individual's serum that is at least 1%, 5%, 10%, 15%, 20%, 25%, 35%, 50%, 75%, 100%, 150%, 200%, or 250% longer compared to its conventional counterpart.

[00177] In some embodiments, an Fc portion of a scavenging antibody binds to FcRn. In some embodiments, the Fc portion of a scavenging antibody binds to FcRn at a pH of 7.4 with a Kd ranging from 10⁻³M to 10⁻⁸M. In some embodiments, a scavenging antibody binds to FcRn at a pH of 7.4 with a Kd ranging from 10⁻³M to 10⁻⁷M, from 10⁻³M to 10⁻⁶M, from 10⁻³M to 10⁻⁵M, from 10⁻³M to 10⁻⁴M, from 10⁻⁴M to 10⁻⁷M, from 10⁻⁴M to 10⁻⁶M, from 10⁻⁴M to 10⁻⁵M, from 10⁻⁵M to 10⁻⁸M, from 10⁻⁵M to 10⁻⁷ ...�M to 10⁻⁸M, from 10⁻⁶M to 10⁻⁷M, or from 10⁻⁷M to 10⁻⁸M. In some embodiments, FcRn binds to the CH2-CH3 hinge region of a scavenging antibody. In some embodiments, FcRn binds to the same region as protein A or protein G. In some embodiments, FcRn binds to a binding site different from FcyRs. In some embodiments, the Petition 870210013044, dated 08 / 02 / 2021, p. 81 / 205 72 / 190 amino acid (AA) residues from an Fc region of the scavenging antibody are required for binding to FcRn. In some embodiments, the amino acid (AA) residues of an Fc region of the scavenging antibody affect binding to FcRn.

[00178] In some embodiments, any of the antibodies provided in this descriptive report is genetically modified to bind to FcRn with higher affinity. In some embodiments, any of the antibodies provided in this descriptive report is genetically modified to bind to FcRn with higher affinity at pH 7.4. In some embodiments, the affinity of scavenging antibodies for FcRn is increased to extend their pharmacokinetic (PK) properties when compared to their conventional counterparts. For example, in some embodiments, scavenging antibodies evoke fewer adverse reactions due to their effectiveness at lower doses. In some embodiments, scavenging antibodies are administered less frequently. In some embodiments, the transcytosis of scavenging antibodies to certain tissue types is increased. In some embodiments, scavenging antibodies increase the efficiency of transplacental delivery.In some applications, the cleaning antibodies have lower production costs.

[00179] In some embodiments, any of the antibodies provided in this descriptive report is genetically modified to bind to FcRn with lower affinity. In some embodiments, any of the antibodies provided in this descriptive report is genetically modified to bind to FcRn with lower affinity at pH 7.4. In some embodiments, the affinity of antibodies of Petition 870210013044, dated 08 / 02 / 2021, p. 82 / 205 72 / 190 amino acid (AA) residues from an Fc region of the scavenging antibody are required for binding to FcRn. In some embodiments, the amino acid (AA) residues of an Fc region of the scavenging antibody affect binding to FcRn.

[00178] In some embodiments, any of the antibodies provided in this descriptive report is genetically modified to bind to FcRn with higher affinity. In some embodiments, any of the antibodies provided in this descriptive report is genetically modified to bind to FcRn with higher affinity at pH 7.4. In some embodiments, the affinity of scavenging antibodies for FcRn is increased to extend their pharmacokinetic (PK) properties when compared to their conventional counterparts. For example, in some embodiments, scavenging antibodies evoke fewer adverse reactions due to their effectiveness at lower doses. In some embodiments, scavenging antibodies are administered less frequently. In some embodiments, the transcytosis of scavenging antibodies to certain tissue types is increased. In some embodiments, scavenging antibodies increase the efficiency of transplacental delivery.In some applications, the cleaning antibodies have lower production costs.

[00179] In some embodiments, any of the antibodies provided in this descriptive report is genetically modified to bind to FcRn with lower affinity. In some embodiments, any of the antibodies provided in this descriptive report is genetically modified to bind to FcRn with lower affinity at pH 7.4. In some embodiments, the affinity of antibodies of Petition 870210013044, dated 08 / 02 / 2021, page 82 / 205 73 / 190 clearance to FcRn is reduced to shorten its pharmacokinetic (PK) properties when compared to its conventional counterparts. For example, in some modalities, clearance antibodies are more rapidly cleared for imaging and / or radioimmunotherapy. In some modalities, clearance antibodies promote the clearance of endogenous pathogenic antibodies as a treatment for autoimmune diseases. In some modalities, clearance antibodies reduce the risk of adverse pregnancy outcome, which can be caused by transplacental transport of fetus-specific antibody material.

[00180] In some embodiments, scavenging antibodies have decreased affinity for an antigen at a low pH compared to a neutral or physiological pH (e.g., pH 7.4). In some embodiments, scavenging antibodies have decreased affinity for an antigen at an acidic pH (e.g., a pH ranging from 5.5 to 6.5) compared to a physiological pH (e.g., pH 7.4). It should be noted that any of the antibodies provided in this descriptive report may be genetically modified to dissociate from the antigen depending on changes in pH (e.g., pH-sensitive antibodies). In some embodiments, the scavenging antibodies provided in this descriptive report are genetically modified to bind to the antigen depending on the pH. In some embodiments, the scavenging antibodies provided in this descriptive report are genetically modified to bind to FcRn depending on the pH.In some embodiments, the scavenging antibodies provided in this descriptive report are internalized by endocytosis. In some embodiments, Petition 870210013044, dated 08 / 02 / 2021, page 83 / 205 73 / 190 clearance to FcRn is reduced to shorten its pharmacokinetic (PK) properties when compared to its conventional counterparts. For example, in some modalities, clearance antibodies are more rapidly cleared for imaging and / or radioimmunotherapy. In some modalities, clearance antibodies promote the clearance of endogenous pathogenic antibodies as a treatment for autoimmune diseases. In some modalities, clearance antibodies reduce the risk of adverse pregnancy outcome, which can be caused by transplacental transport of fetus-specific antibody material.

[00180] In some embodiments, scavenging antibodies have decreased affinity for an antigen at a low pH compared to a neutral or physiological pH (e.g., pH 7.4). In some embodiments, scavenging antibodies have decreased affinity for an antigen at an acidic pH (e.g., a pH ranging from 5.5 to 6.5) compared to a physiological pH (e.g., pH 7.4). It should be noted that any of the antibodies provided in this descriptive report may be genetically modified to dissociate from the antigen depending on changes in pH (e.g., pH-sensitive antibodies). In some embodiments, the scavenging antibodies provided in this descriptive report are genetically modified to bind to the antigen depending on the pH. In some embodiments, the scavenging antibodies provided in this descriptive report are genetically modified to bind to FcRn depending on the pH.In some embodiments, the scavenging antibodies provided in this descriptive report are internalized by endocytosis. In some embodiments, Petition 870210013044, dated 08 / 02 / 2021, page 83 / 205 74 / 190 scavenging antibodies provided in this descriptive report are internalized by binding to FcRn. In some embodiments, the endocytosed scavenging antibodies release antigen into an endosome. In some embodiments, the scavenging antibodies are recycled back to the cell surface. In some embodiments, the scavenging antibodies remain attached to the cells. In some embodiments, the endocytosed scavenging antibodies are recycled back to the plasma. It should be noted that the Fc portion of any of the antibodies provided in this descriptive report may be genetically modified to have different FcRn binding activity. In some embodiments, the FcRn binding activity affects the clearance time of an antigen by a scavenging antibody. In some embodiments, the scavenging antibodies may be long-acting or short-acting scavenging antibodies.

[00181] In some embodiments, the conversion of a conventional therapeutic antibody into a scavenger antibody reduces the effective dose. In some embodiments, the conversion of a conventional therapeutic antibody into a scavenger antibody reduces the effective dose by at least 1%, 2%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, or 99%. In some embodiments, the conversion of a conventional therapeutic antibody into a scavenger antibody reduces the effective dose by at least 1.5 times, 2 times, 3 times, 4 times, 5 times, 6 times, 8 times, 10 times, 15 times, 20 times, 50 times, or 100 times.

[00182] In some embodiments, the selection of an appropriate dose of a scavenging antibody for therapy can be performed empirically. In some embodiments, a dose Petition 870210013044, dated 08 / 02 / 2021, p. 84 / 205 74 / 190 scavenging antibodies provided in this descriptive report are internalized by binding to FcRn. In some embodiments, the endocytosed scavenging antibodies release antigen into an endosome. In some embodiments, the scavenging antibodies are recycled back to the cell surface. In some embodiments, the scavenging antibodies remain attached to the cells. In some embodiments, the endocytosed scavenging antibodies are recycled back to the plasma. It should be noted that the Fc portion of any of the antibodies provided in this descriptive report may be genetically modified to have different FcRn binding activity. In some embodiments, the FcRn binding activity affects the clearance time of an antigen by a scavenging antibody. In some embodiments, the scavenging antibodies may be long-acting or short-acting scavenging antibodies.

[00181] In some embodiments, the conversion of a conventional therapeutic antibody into a scavenger antibody reduces the effective dose. In some embodiments, the conversion of a conventional therapeutic antibody into a scavenger antibody reduces the effective dose by at least 1%, 2%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, or 99%. In some embodiments, the conversion of a conventional therapeutic antibody into a scavenger antibody reduces the effective dose by at least 1.5 times, 2 times, 3 times, 4 times, 5 times, 6 times, 8 times, 10 times, 15 times, 20 times, 50 times, or 100 times.

[00182] In some embodiments, the selection of an appropriate dose of a scavenging antibody for therapy can be performed empirically. In some embodiments, a dose Petition 870210013044, dated 08 / 02 / 2021, p. 84 / 205 A high dose of a 75 / 190 clearance antibody can saturate FcRN, resulting in antibodies that stabilize the antigen in the serum without being internalized. In some modalities, a low dose of a clearance antibody may not be therapeutically effective. In some modalities, clearance antibodies are administered once daily, once weekly, once every two weeks, once every three weeks, once every four weeks, once every six weeks, once every eight weeks, once every ten weeks, once every twelve weeks, once every sixteen weeks, once every twenty weeks, or once every twenty-four weeks.

[00183] In some embodiments, any of the antibodies provided in this descriptive report may be genetically modified or altered to be scavenging antibodies. In some embodiments, any of the antibodies provided in this descriptive report may be converted into a scavenging antibody using any suitable method. For example, suitable methods for producing scavenging antibodies have been previously described in Igawa et al., (2013) “Engineered Monoclonal Antibody with Novel Antigen-Sweeping Activity In Vivo”, PLoS ONE 8(5): e63236; and Igawa et al., “pH-Dependent Antigen-Binding Antibodies as a Novel Therapeutic Modality”, Biochimica et Biophysica Acta 1844 (2014) 1943-1950; the contents of each of which are incorporated into this descriptive report by reference. It should be noted, however, that the methods for producing clearance antibodies as provided in this descriptive report are not intended to be exhaustive.Therefore, additional methods for producing scavenging antibodies fall within the scope of this discovery. Petition 870210013044, dated 08 / 02 / 2021, p. 85 / 205 A high dose of a 75 / 190 clearance antibody can saturate FcRN, resulting in antibodies that stabilize the antigen in the serum without being internalized. In some modalities, a low dose of a clearance antibody may not be therapeutically effective. In some modalities, clearance antibodies are administered once daily, once weekly, once every two weeks, once every three weeks, once every four weeks, once every six weeks, once every eight weeks, once every ten weeks, once every twelve weeks, once every sixteen weeks, once every twenty weeks, or once every twenty-four weeks.

[00183] In some embodiments, any of the antibodies provided in this descriptive report may be genetically modified or altered to be scavenging antibodies. In some embodiments, any of the antibodies provided in this descriptive report may be converted into a scavenging antibody using any suitable method. For example, suitable methods for producing scavenging antibodies have been previously described in Igawa et al., (2013) “Engineered Monoclonal Antibody with Novel Antigen-Sweeping Activity In Vivo”, PLoS ONE 8(5): e63236; and Igawa et al., “pH-Dependent Antigen-Binding Antibodies as a Novel Therapeutic Modality”, Biochimica et Biophysica Acta 1844 (2014) 1943-1950; the contents of each of which are incorporated into this descriptive report by reference. It should be noted, however, that the methods for producing clearance antibodies as provided in this descriptive report are not intended to be exhaustive.Therefore, additional methods for producing scavenging antibodies fall within the scope of this discovery. Petition 870210013044, dated 08 / 02 / 2021, pages 85 / 205 76 / 190

[00184] Some aspects of the disclosure are based on the recognition that the affinity (e.g., as expressed as Kd) of any of the anti-promyostatin / latent myostatin antibodies provided in this descriptive report is sensitive to changes in pH. In some embodiments, the antibodies provided in this descriptive report have an increased promyostatin / latent myostatin binding Kd at a relatively low pH (e.g., a pH ranging from 4.0 to 6.5) when compared to a relatively high pH (e.g., a pH ranging from 7.0 to 7.4). In some embodiments, the antibodies provided in this descriptive report have a promyostatin / latent myostatin binding Kd ranging from 10⁻³ M, 10⁻⁴ M, 10⁻⁵ M, 10⁻⁶ M, 10⁻⁷ M, 10⁻⁸ M when the pH is between 4.0 and 6.5.In some embodiments, the antibodies provided in this descriptive report have a promyostatin / latent myostatin binding Kd that varies from 10⁻⁶M, 10⁻⁷M, 10⁻⁸M, 10⁻⁹M, 10⁻¹⁰M, 10⁻¹¹M when the pH is between 7.0 and 7.4. In some embodiments, the antibodies provided in this descriptive report have a promyostatin / latent myostatin binding Kd that is at least 2 times, at least 10 times, at least 50 times, at least 100 times, at least 500 times, at least 1,000 times, at least 5,000 times, or at least 10,000 times greater at a pH between 4.0 and 6.5, when compared to a pH between 7.0 and 7.4.

[00185] In some embodiments, antibodies to promiostatin / latent myostatin that do not specifically bind to an epitope within the sequence are provided in this descriptive report. Petition 870210013044, dated 08 / 02 / 2021, pages 86 / 205 76 / 190

[00184] Some aspects of the disclosure are based on the recognition that the affinity (e.g., as expressed as Kd) of any of the anti-promyostatin / latent myostatin antibodies provided in this descriptive report is sensitive to changes in pH. In some embodiments, the antibodies provided in this descriptive report have an increased promyostatin / latent myostatin binding Kd at a relatively low pH (e.g., a pH ranging from 4.0 to 6.5) when compared to a relatively high pH (e.g., a pH ranging from 7.0 to 7.4). In some embodiments, the antibodies provided in this descriptive report have a promyostatin / latent myostatin binding Kd ranging from 10⁻³ M, 10⁻⁴ M, 10⁻⁵ M, 10⁻⁶ M, 10⁻⁷ M, 10⁻⁸ M when the pH is between 4.0 and 6.5.In some embodiments, the antibodies provided in this descriptive report have a promyostatin / latent myostatin binding Kd that varies from 10⁻⁶M, 10⁻⁷M, 10⁻⁸M, 10⁻⁹M, 10⁻¹⁰M, 10⁻¹¹M when the pH is between 7.0 and 7.4. In some embodiments, the antibodies provided in this descriptive report have a promyostatin / latent myostatin binding Kd that is at least 2 times, at least 10 times, at least 50 times, at least 100 times, at least 500 times, at least 1,000 times, at least 5,000 times, or at least 10,000 times greater at a pH between 4.0 and 6.5, when compared to a pH between 7.0 and 7.4.

[00185] In some embodiments, antibodies to promiostatin / latent myostatin that do not specifically bind to an epitope within the sequence are provided in this descriptive report. Petition 870210013044, dated 08 / 02 / 2021, pages 86 / 205 77 / 190 amino acids shown as (Seq. ID No.: 64). In some embodiments, the antibodies to promyostatin / latent myostatin provided in this descriptive report do not specifically bind to the same epitope as an antibody described in Table 2a, 11a, 11b, or 13 of International Patent Application Publication No. WO 2016 / 098357, which was published on June 23, 2016, and which is based on International Patent Application No. PCT / JP2015 / 006323, which was filed on December 18, 2015. In some embodiments, the antibodies to promyostatin / latent myostatin provided in this descriptive report do not compete or do not cross-compete for binding to the same epitope as an antibody described in Table 2a, 11a, 11b, or 13 of International Patent Application Publication No. WO 2016 / 098357, which was published on June 23, 2016. from 2016, and which is based on International Patent Application No. PCT / JP2015 / 006323, which was filed on December 18, 2015.In some embodiments, the antibodies to promyostatin / latent myostatin provided in this descriptive report do not specifically bind to the same epitope as an antibody comprising a VH and VL pair described in Table 2a, 11a, 11b, or 13 of International Patent Application Publication No. WO 2016 / 098357, which was published on June 23, 2016, and which is based on International Patent Application No. PCT / JP2015 / 006323, which was filed on December 18, 2015. In some embodiments, the antibodies to promyostatin / latent myostatin provided in this descriptive report do not compete or do not cross-compete for binding to the same epitope as an antibody comprising a VH and VL pair described in Table 2a, 11a, 11b, or 13 of the International Patent Application Publication. Petition 870210013044, dated 08 / 02 / 2021, p. 87 / 205 77 / 190 amino acids shown as (Seq. ID No.: 64). In some embodiments, the antibodies to promyostatin / latent myostatin provided in this descriptive report do not specifically bind to the same epitope as an antibody described in Table 2a, 11a, 11b, or 13 of International Patent Application Publication No. WO 2016 / 098357, which was published on June 23, 2016, and which is based on International Patent Application No. PCT / JP2015 / 006323, which was filed on December 18, 2015. In some embodiments, the antibodies to promyostatin / latent myostatin provided in this descriptive report do not compete or do not cross-compete for binding to the same epitope as an antibody described in Table 2a, 11a, 11b, or 13 of International Patent Application Publication No. WO 2016 / 098357, which was published on June 23, 2016. from 2016, and which is based on International Patent Application No. PCT / JP2015 / 006323, which was filed on December 18, 2015.In some embodiments, the antibodies to promyostatin / latent myostatin provided in this descriptive report do not specifically bind to the same epitope as an antibody comprising a VH and VL pair described in Table 2a, 11a, 11b, or 13 of International Patent Application Publication No. WO 2016 / 098357, which was published on June 23, 2016, and which is based on International Patent Application No. PCT / JP2015 / 006323, which was filed on December 18, 2015. In some embodiments, the antibodies to promyostatin / latent myostatin provided in this descriptive report do not compete or do not cross-compete for binding to the same epitope as an antibody comprising a VH and VL pair described in Table 2a, 11a, 11b, or 13 of the International Patent Application Publication. Petition 870210013044, dated 08 / 02 / 2021, p. 87 / 205 78 / 190 No. WO 2016 / 098357, which was published on June 23, 2016, and which is based on International Patent Application No. PCT / JP2015 / 006323, which was filed on December 18, 2015. Polypeptides

[00186] Some aspects of the disclosure relate to a polypeptide having a sequence selected from the group consisting of SEQ. ID. NO.: 24, SEQ. ID. NO.: 25, SEQ. ID. NO.: 26, SEQ. ID. NO.: 27, SEQ. ID. NO.: 28, and SEQ. ID. NO.: 29. In some embodiments, the polypeptide is a variable heavy chain domain. In some embodiments, the polypeptide is at least 75% (e.g., 80%, 85%, 90%, 95%, 98%, or 99%) identical to any of the amino acid sequences shown in SEQ. ID. NO.: 24, SEQ. ID. NO.: 25, SEQ. ID. NO.: 26, SEQ. ID. NO.: 27, SEQ. ID. No.: 28 or ID. OF SEQ. No. 29.

[00187] Some aspects of the disclosure relate to a polypeptide having a sequence selected from the group consisting of SEQ. ID. NO.: 30, SEQ. ID. NO.: 31, SEQ. ID. NO.: 32, SEQ. ID. NO.: 33, SEQ. ID. NO.: 34, and SEQ. ID. NO.: 35. In some embodiments, the polypeptide is a variable light chain domain. In some embodiments, the polypeptide is at least 75% (e.g., 80%, 85%, 90%, 95%, 98%, or 99%) identical to any of the amino acid sequences shown in SEQ. ID. NO.: 30, SEQ. ID. NO.: 31, SEQ. ID. NO.: 32, SEQ. ID. NO.: 33, SEQ. ID. No.: 34 or ID. OF SEQ. No. 35. Antibodies that compete with anti-promyostatin / latent myostatin antibodies

[00188] Aspects of revelation are related to Petition 870210013044, dated 08 / 02 / 2021, p. 88 / 205 78 / 190 No. WO 2016 / 098357, which was published on June 23, 2016, and which is based on International Patent Application No. PCT / JP2015 / 006323, which was filed on December 18, 2015. Polypeptides

[00186] Some aspects of the disclosure relate to a polypeptide having a sequence selected from the group consisting of SEQ. ID. NO.: 24, SEQ. ID. NO.: 25, SEQ. ID. NO.: 26, SEQ. ID. NO.: 27, SEQ. ID. NO.: 28, and SEQ. ID. NO.: 29. In some embodiments, the polypeptide is a variable heavy chain domain. In some embodiments, the polypeptide is at least 75% (e.g., 80%, 85%, 90%, 95%, 98%, or 99%) identical to any of the amino acid sequences shown in SEQ. ID. NO.: 24, SEQ. ID. NO.: 25, SEQ. ID. NO.: 26, SEQ. ID. NO.: 27, SEQ. ID. No.: 28 or ID. OF SEQ. No. 29.

[00187] Some aspects of the disclosure relate to a polypeptide having a sequence selected from the group consisting of SEQ. ID. NO.: 30, SEQ. ID. NO.: 31, SEQ. ID. NO.: 32, SEQ. ID. NO.: 33, SEQ. ID. NO.: 34, and SEQ. ID. NO.: 35. In some embodiments, the polypeptide is a variable light chain domain. In some embodiments, the polypeptide is at least 75% (e.g., 80%, 85%, 90%, 95%, 98%, or 99%) identical to any of the amino acid sequences shown in SEQ. ID. NO.: 30, SEQ. ID. NO.: 31, SEQ. ID. NO.: 32, SEQ. ID. NO.: 33, SEQ. ID. No.: 34 or ID. OF SEQ. No. 35. Antibodies that compete with anti-promyostatin / latent myostatin antibodies

[00188] Aspects of revelation are related to Petition 870210013044, dated 08 / 02 / 2021, p. 88 / 205 79 / 190 antibodies that compete or cross-compete with any of the antibodies provided in this descriptive report. The term "compete," as used in this descriptive report with respect to an antibody, means that a first antibody binds to an epitope of a protein (e.g., latent myostatin) in a manner sufficiently similar to the binding of a second antibody, such that the binding of the first antibody to its epitope is detectably diminished in the presence of the second antibody, compared with the binding of the first antibody in the absence of the second antibody. Alternatively, the binding of the second antibody to its epitope is also detectably diminished in the presence of the first antibody may, but not necessarily, be the case. That is, a first antibody may inhibit the binding of a second antibody to its epitope without the second antibody inhibiting the binding of the first antibody to its respective epitope.However, when each antibody detectably inhibits the binding of the other antibody to its epitope or ligand, whether to the same extent or to a greater or lesser extent, the antibodies are said to cross-compete with each other for binding to their respective epitope (or epitopes). Both competing and cross-competing antibodies fall within the scope of this discovery. Regardless of the mechanism by which this competition or cross-competition occurs (e.g., steric hindrance, conformational change, or binding to a common epitope, or portion thereof), those skilled in the art would observe that these competing and / or cross-competing antibodies are encompassed and can be... Petition 870210013044, dated 08 / 02 / 2021, pages 89 / 205 79 / 190 antibodies that compete or cross-compete with any of the antibodies provided in this descriptive report. The term "compete," as used in this descriptive report with respect to an antibody, means that a first antibody binds to an epitope of a protein (e.g., latent myostatin) in a manner sufficiently similar to the binding of a second antibody, such that the binding of the first antibody to its epitope is detectably diminished in the presence of the second antibody, compared with the binding of the first antibody in the absence of the second antibody. Alternatively, the binding of the second antibody to its epitope is also detectably diminished in the presence of the first antibody may, but not necessarily, be the case. That is, a first antibody may inhibit the binding of a second antibody to its epitope without the second antibody inhibiting the binding of the first antibody to its respective epitope.However, when each antibody detectably inhibits the binding of the other antibody to its epitope or ligand, whether to the same extent or to a greater or lesser extent, the antibodies are said to cross-compete with each other for binding to their respective epitope (or epitopes). Both competing and cross-competing antibodies fall within the scope of this discovery. Regardless of the mechanism by which this competition or cross-competition occurs (e.g., steric hindrance, conformational change, or binding to a common epitope, or portion thereof), those skilled in the art would observe that these competing and / or cross-competing antibodies are encompassed and can be... Petition 870210013044, dated 08 / 02 / 2021, pages 89 / 205 80 / 190 useful for the methods and / or compositions provided in this descriptive report.

[00189] Aspects of the disclosure relate to antibodies that compete or cross-compete with any of the antibodies provided in this descriptive report. In some embodiments, an antibody binds to the same epitope, or near it, as any of the antibodies provided in this descriptive report. In some embodiments, an antibody binds near an epitope if it binds within 15 or fewer amino acid residues of the epitope. In some embodiments, any of the antibodies provided in this descriptive report binds within 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 amino acid residues of an epitope that is bound by any of the antibodies provided in this descriptive report.

[00190] In another embodiment, an antibody competes or cross-competes for binding to any of the antigens provided in this descriptive report (e.g., promyostatin / latent myostatin) with an equilibrium dissociation constant, Kd, ​​between the antibody and the protein of less than 10⁻⁶ M. In other embodiments, an antibody competes or cross-competes for binding to any of the antigens provided in this descriptive report with a Kd in the range of 10⁻¹¹ M to 10⁻⁶ M.

[00191] Aspects of the disclosure relate to antibodies that compete for binding to promyostatin / latent myostatin with any of the antibodies provided in this descriptive report. In some embodiments, the antibody binds to promyostatin / latent myostatin at the same epitope as any of the antibodies. Petition 870210013044, dated 08 / 02 / 2021, pp. 90 / 205 80 / 190 useful for the methods and / or compositions provided in this descriptive report.

[00189] Aspects of the disclosure relate to antibodies that compete or cross-compete with any of the antibodies provided in this descriptive report. In some embodiments, an antibody binds to the same epitope, or near it, as any of the antibodies provided in this descriptive report. In some embodiments, an antibody binds near an epitope if it binds within 15 or fewer amino acid residues of the epitope. In some embodiments, any of the antibodies provided in this descriptive report binds within 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 amino acid residues of an epitope that is bound by any of the antibodies provided in this descriptive report.

[00190] In another embodiment, an antibody competes or cross-competes for binding to any of the antigens provided in this descriptive report (e.g., promyostatin / latent myostatin) with an equilibrium dissociation constant, Kd, ​​between the antibody and the protein of less than 10⁻⁶ M. In other embodiments, an antibody competes or cross-competes for binding to any of the antigens provided in this descriptive report with a Kd in the range of 10⁻¹¹ M to 10⁻⁶ M.

[00191] Aspects of the disclosure relate to antibodies that compete for binding to promyostatin / latent myostatin with any of the antibodies provided in this descriptive report. In some embodiments, the antibody binds to promyostatin / latent myostatin at the same epitope as any of the antibodies. Petition 870210013044, dated 08 / 02 / 2021, pp. 90 / 205 81 / 190 provided in this descriptive report. For example, in some embodiments, any of the antibodies provided in this descriptive report binds to or near a toloid cleavage site, or to or near a toloid anchoring site of promyostatin / latent myostatin. In other embodiments, any of the antibodies provided in this descriptive report binds to or near a proprotein convertase cleavage site, or to or near a proprotein convertase anchoring site of promyostatin / latent myostatin. In another embodiment, an antibody competes for binding to promyostatin / latent myostatin with an equilibrium dissociation constant, Kd, ​​between the antibody and promyostatin / latent myostatin of less than 10⁻⁶ M. In other embodiments, the antibody that competes with any of the antibodies provided in this descriptive report binds to promyostatin / latent myostatin with a Kd ranging from 10⁻¹¹ M to 10⁻⁶ M.

[00192] Any of the antibodies provided in this descriptive report can be characterized using any suitable methods. For example, one method consists of identifying the epitope to which the antigen binds, or “epitope mapping”. There are many suitable methods for mapping and characterizing the location of epitopes on proteins, including solution of the crystal structure of an antigen-antibody complex, competition assays, gene fragment expression assays, and synthetic peptide-based assays, as described, for example, in Chapter 11 of Harlow and Lane, “Using Antibodies, a Laboratory Manual”, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, Petition 870210013044, dated 08 / 02 / 2021, pages 91 / 205 81 / 190 provided in this descriptive report. For example, in some embodiments, any of the antibodies provided in this descriptive report binds to or near a toloid cleavage site, or to or near a toloid anchoring site of promyostatin / latent myostatin. In other embodiments, any of the antibodies provided in this descriptive report binds to or near a proprotein convertase cleavage site, or to or near a proprotein convertase anchoring site of promyostatin / latent myostatin. In another embodiment, an antibody competes for binding to promyostatin / latent myostatin with an equilibrium dissociation constant, Kd, ​​between the antibody and promyostatin / latent myostatin of less than 10⁻⁶ M. In other embodiments, the antibody that competes with any of the antibodies provided in this descriptive report binds to promyostatin / latent myostatin with a Kd ranging from 10⁻¹¹ M to 10⁻⁶ M.

[00192] Any of the antibodies provided in this descriptive report can be characterized using any suitable methods. For example, one method consists of identifying the epitope to which the antigen binds, or “epitope mapping”. There are many suitable methods for mapping and characterizing the location of epitopes on proteins, including solution of the crystal structure of an antigen-antibody complex, competition assays, gene fragment expression assays, and synthetic peptide-based assays, as described, for example, in Chapter 11 of Harlow and Lane, “Using Antibodies, a Laboratory Manual”, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, Petition 870210013044, dated 08 / 02 / 2021, pages 91 / 205 82 / 190 NY, 1999. In a further example, epitope mapping can be used to determine the sequence to which an antibody binds. The epitope can be a linear epitope, i.e., contained in a single amino acid stretch, or a conformational epitope formed by a three-dimensional interaction of amino acids that may not necessarily be contained in a single stretch (linear sequence of the primary structure). Peptides of varying lengths (e.g., at least 4-6 amino acids in length) can be isolated or synthesized (e.g., recombinantly) and used for antibody binding assays. In another example, the epitope to which the antibody binds can be determined in a systematic assessment by using overlapping peptides derived from the target antigen sequence and determining antibody binding.According to gene fragment expression assays, the open reading frame encoding the target antigen is fragmented randomly or by specific genetic constructs, and the reactivity of the expressed antigen fragments with the antibody to be tested is determined. Gene fragments can, for example, be produced by PCR and then transcribed and translated into protein in vitro, in the presence of radioactive amino acids. Antibody binding to radioactively labeled antigen fragments is then determined by immunoprecipitation and gel electrophoresis. Certain epitopes can also be identified using large libraries of random peptide sequences displayed on the surface of phage particles (phage libraries). Alternatively, a defined library of fragments of... Petition 870210013044, dated 08 / 02 / 2021, pages 92 / 205 82 / 190 NY, 1999. In a further example, epitope mapping can be used to determine the sequence to which an antibody binds. The epitope can be a linear epitope, i.e., contained in a single amino acid stretch, or a conformational epitope formed by a three-dimensional interaction of amino acids that may not necessarily be contained in a single stretch (linear sequence of the primary structure). Peptides of varying lengths (e.g., at least 4-6 amino acids in length) can be isolated or synthesized (e.g., recombinantly) and used for antibody binding assays. In another example, the epitope to which the antibody binds can be determined in a systematic assessment by using overlapping peptides derived from the target antigen sequence and determining antibody binding.According to gene fragment expression assays, the open reading frame encoding the target antigen is fragmented randomly or by specific genetic constructs, and the reactivity of the expressed antigen fragments with the antibody to be tested is determined. Gene fragments can, for example, be produced by PCR and then transcribed and translated into protein in vitro, in the presence of radioactive amino acids. Antibody binding to radioactively labeled antigen fragments is then determined by immunoprecipitation and gel electrophoresis. Certain epitopes can also be identified using large libraries of random peptide sequences displayed on the surface of phage particles (phage libraries). Alternatively, a defined library of fragments of... Petition 870210013044, dated 08 / 02 / 2021, pages 92 / 205 83 / 190 overlapping peptides can be tested by binding to the test antibody in single-binding assays. In a further example, antigen-binding domain mutagenesis, domain exchange experiments, and alanine-scavenging mutagenesis can be performed to identify required, sufficient, and / or necessary residues for epitope binding. For example, domain exchange experiments can be performed using a target antigen mutant in which several fragments of the promyostatin / latent myostatin polypeptide have been replaced (swapped) with sequences from a closely related but antigenically distinct protein, for example, another member of the TGFp protein family (e.g., GDF11). By assessing antibody binding to the mutant promyostatin / latent myostatin, the importance of the particular antigen fragment for antibody binding can be evaluated.

[00193] Alternatively, competition assays can be performed using other antibodies known to bind to the same antigen to determine if an antibody binds to the same epitope as the other antibodies. Competition assays are well known to those skilled in the art. Any of the suitable methods, for example, epitope mapping methods as described in this descriptive report, can be applied to determine if an anti-promyostatin / latent myostatin antibody binds to one or more of the specific residues / segments in promyostatin / latent myostatin, as described in this descriptive report. Furthermore, the interaction of the antibody with one or more of those defined residues in promyostatin Petition 870210013044, dated 08 / 02 / 2021, pages 93 / 205 83 / 190 overlapping peptides can be tested by binding to the test antibody in single-binding assays. In a further example, antigen-binding domain mutagenesis, domain exchange experiments, and alanine-scavenging mutagenesis can be performed to identify required, sufficient, and / or necessary residues for epitope binding. For example, domain exchange experiments can be performed using a target antigen mutant in which several fragments of the promyostatin / latent myostatin polypeptide have been replaced (swapped) with sequences from a closely related but antigenically distinct protein, for example, another member of the TGFp protein family (e.g., GDF11). By assessing antibody binding to the mutant promyostatin / latent myostatin, the importance of the particular antigen fragment for antibody binding can be evaluated.

[00193] Alternatively, competition assays can be performed using other antibodies known to bind to the same antigen to determine if an antibody binds to the same epitope as the other antibodies. Competition assays are well known to those skilled in the art. Any of the suitable methods, for example, epitope mapping methods as described in this descriptive report, can be applied to determine if an anti-promyostatin / latent myostatin antibody binds to one or more of the specific residues / segments in promyostatin / latent myostatin, as described in this descriptive report. Furthermore, the interaction of the antibody with one or more of those defined residues in promyostatin Petition 870210013044, dated 08 / 02 / 2021, pages 93 / 205 84 / 190 myostatin / latent myostatin can be determined by routine technology. For example, a crystal structure can be determined, and the distances between residues in promyostatin / latent myostatin and one or more residues in the antibody can be determined accordingly. Based on this distance, it can be determined whether a specific residue in promyostatin / latent myostatin interacts with one or more residues in the antibody. Furthermore, suitable methods, for example, competition assays and target mutagenesis assays, can be applied to determine the preferential binding of a candidate anti-promyostatin / latent myostatin antibody to promyostatin / latent myostatin, as compared to another target such as, for example, a mutant promyostatin / latent myostatin. Production of antibodies that bind to promiostatin / latent myostatin.

[00194] Various methods can be used to obtain antibodies, or antigen-binding fragments thereof, from detection. For example, antibodies can be produced using recombinant DNA methods. Monoclonal antibodies can also be produced by hybridoma generation (see, for example, Kohler and Milstein (1975) Nature, 256: 495-499) according to known methods. Hybridomas formed in this way are then evaluated using standardized methods, for example, enzyme-linked immunosorbent assay (ELISA) and surface plasmon resonance analysis (e.g., OCTET or BIACORE), to identify one or more hybridomas that produce an antibody that binds specifically to a specified antigen. Any form of the antigen Petition 870210013044, dated 08 / 02 / 2021, pages 94 / 205 84 / 190 myostatin / latent myostatin can be determined by routine technology. For example, a crystal structure can be determined, and the distances between residues in promyostatin / latent myostatin and one or more residues in the antibody can be determined accordingly. Based on this distance, it can be determined whether a specific residue in promyostatin / latent myostatin interacts with one or more residues in the antibody. Furthermore, suitable methods, for example, competition assays and target mutagenesis assays, can be applied to determine the preferential binding of a candidate anti-promyostatin / latent myostatin antibody to promyostatin / latent myostatin, as compared to another target such as, for example, a mutant promyostatin / latent myostatin. Production of antibodies that bind to promiostatin / latent myostatin.

[00194] Various methods can be used to obtain antibodies, or antigen-binding fragments thereof, from detection. For example, antibodies can be produced using recombinant DNA methods. Monoclonal antibodies can also be produced by hybridoma generation (see, for example, Kohler and Milstein (1975) Nature, 256: 495-499) according to known methods. Hybridomas formed in this way are then evaluated using standardized methods, for example, enzyme-linked immunosorbent assay (ELISA) and surface plasmon resonance analysis (e.g., OCTET or BIACORE), to identify one or more hybridomas that produce an antibody that binds specifically to a specified antigen. Any form of the antigen Petition 870210013044, dated 08 / 02 / 2021, pages 94 / 205 The specified 85 / 190 can be used as the immunogen, for example, recombinant antigen, naturally occurring forms, any variants or fragments thereof, in addition to antigenic peptides thereof (for example, any of the epitopes described in this descriptive report as a linear epitope or within a scaffold as a conformational epitope). An exemplary method of antibody production includes the evaluation of protein expression libraries expressing antibodies or fragments thereof (e.g., scFv), for example, phage or ribosome display libraries. Phage display is described, for example, in Ladner et al., US Patent No. 5,223,409; Smith (1985) Science 228: 1315-1317; Clackson et al., (1991) Nature, 352: 624-628; Marks et al., (1991) J. Mol. Biol., 222: 581597; WO 92 / 18619; WO 91 / 17271; WO 92 / 20791; WO 92 / 15679; WO 93 / 01288; WO 92 / 01047; WO 92 / 09690; and WO 90 / 02809.

[00195] In addition to the use of display libraries, the specified antigen (e.g., promyostatin) can be used to immunize a non-human animal, for example, a rodent, such as a mouse, hamster, or rat. In one embodiment, the non-human animal is a mouse.

[00196] In another embodiment, a monoclonal antibody is obtained from a non-human animal, and then modified, for example, chimerically, using any suitable recombinant DNA techniques. Several approaches to the production of chimeric antibodies have been described. See, for example, Morrison et al., Proc. Natl. Acad. Sci. USA 81: 6.851, 1985; Takeda et al., Nature 314: 452, 1985, Cabilly et al., US Patent No. 4,816,567; Boss et al., US Patent No. 4,816,397; Tanaguchi et al., European Patent Publication Petition 870210013044, dated 08 / 02 / 2021, pages 95 / 205 The specified 85 / 190 can be used as the immunogen, for example, recombinant antigen, naturally occurring forms, any variants or fragments thereof, in addition to antigenic peptides thereof (for example, any of the epitopes described in this descriptive report as a linear epitope or within a scaffold as a conformational epitope). An exemplary method of antibody production includes the evaluation of protein expression libraries expressing antibodies or fragments thereof (e.g., scFv), for example, phage or ribosome display libraries. Phage display is described, for example, in Ladner et al., US Patent No. 5,223,409; Smith (1985) Science 228: 1315-1317; Clackson et al., (1991) Nature, 352: 624-628; Marks et al., (1991) J. Mol. Biol., 222: 581597; WO 92 / 18619; WO 91 / 17271; WO 92 / 20791; WO 92 / 15679; WO 93 / 01288; WO 92 / 01047; WO 92 / 09690; and WO 90 / 02809.

[00195] In addition to the use of display libraries, the specified antigen (e.g., promyostatin) can be used to immunize a non-human animal, for example, a rodent, such as a mouse, hamster, or rat. In one embodiment, the non-human animal is a mouse.

[00196] In another embodiment, a monoclonal antibody is obtained from a non-human animal, and then modified, for example, chimerically, using any suitable recombinant DNA techniques. Several approaches to the production of chimeric antibodies have been described. See, for example, Morrison et al., Proc. Natl. Acad. Sci. USA 81: 6.851, 1985; Takeda et al., Nature 314: 452, 1985, Cabilly et al., US Patent No. 4,816,567; Boss et al., US Patent No. 4,816,397; Tanaguchi et al., European Patent Publication Petition 870210013044, dated 08 / 02 / 2021, pages 95 / 205 86 / 190 EP171496; European Patent Publication 0173494, UK Patent GB 2177096B.

[00197] For additional antibody production techniques, see: “Antibodies: A Laboratory Manual”, eds. Harlow et al., Cold Spring Harbor Laboratory, 1988. The present disclosure is not necessarily limited to any particular source, method of production, or other special characteristics of an antibody.

[00198] Some aspects of the present disclosure relate to host cells transformed with a polynucleotide or vector. Host cells can be prokaryotic or eukaryotic cells. The polynucleotide or vector present in the host cell can be integrated into the host cell genome or it can be maintained extrachromosomally. The host cell can be any prokaryotic or eukaryotic cell, for example, a bacterial, insect, fungal, plant, animal, or human cell. In some embodiments, fungal cells are, for example, those of the genus Saccharomyces, in particular those of the species S. cerevisiae. The term “prokaryotic” includes all bacteria that can be transformed or transfected with DNA or RNA molecules for the expression of an antibody or the corresponding immunoglobulin chains. Prokaryotic hosts can include Gram-negative and Gram-positive bacteria such as, for example, E. coli, S.Typhimurium, Serratia marcescens, and Bacillus subtilis. The term "eukaryotic" includes yeast, higher plants, insects, and vertebrate cells, for example, mammalian cells, such as NSO and CHO cells. Depending on the host employed in a... Petition 870210013044, dated 08 / 02 / 2021, pages 96 / 205 86 / 190 EP171496; European Patent Publication 0173494, UK Patent GB 2177096B.

[00197] For additional antibody production techniques, see: “Antibodies: A Laboratory Manual”, eds. Harlow et al., Cold Spring Harbor Laboratory, 1988. The present disclosure is not necessarily limited to any particular source, method of production, or other special characteristics of an antibody.

[00198] Some aspects of the present disclosure relate to host cells transformed with a polynucleotide or vector. Host cells can be prokaryotic or eukaryotic cells. The polynucleotide or vector present in the host cell can be integrated into the host cell genome or it can be maintained extrachromosomally. The host cell can be any prokaryotic or eukaryotic cell, for example, a bacterial, insect, fungal, plant, animal, or human cell. In some embodiments, fungal cells are, for example, those of the genus Saccharomyces, in particular those of the species S. cerevisiae. The term "prokaryotic" includes all bacteria that can be transformed or transfected with DNA or RNA molecules for the expression of an antibody or the corresponding immunoglobulin chains. Prokaryotic hosts can include Gram-negative and Gram-positive bacteria such as, for example, E. coli, S.Typhimurium, Serratia marcescens, and Bacillus subtilis. The term "eukaryotic" includes yeast, higher plants, insects, and vertebrate cells, for example, mammalian cells, such as NSO and CHO cells. Depending on the host employed in a... Petition 870210013044, dated 08 / 02 / 2021, pages 96 / 205 In the 87 / 190 recombinant production procedure, the antibodies or immunoglobulin chains encoded by the polynucleotide may be glycosylated or non-glycosylated. Antibodies or the corresponding immunoglobulin chains may also include an initial methionine amino acid residue.

[00199] In some embodiments, after a vector has been incorporated into a suitable host, the host can be maintained under conditions suitable for high-level expression of the nucleotide sequences and, as desired, the collection and purification of immunoglobulin light chains, heavy chains, light / heavy chain dimers or intact antibodies, antigen-binding fragments or other forms of immunoglobulin can follow; see Beychok, “Cells of Immunoglobulin Synthesis”, Academic Press, NY, (1979). In this way, polynucleotides or vectors are introduced into cells which, in turn, produce the antibody or antigen-binding fragments. In addition, transgenic animals, preferably mammals, comprising the aforementioned host cells, can be used for the large-scale production of the antibody or antibody fragments.

[00200] Transformed host cells can be grown in fermenters and cultured using any appropriate techniques to achieve optimal cell growth. Once expressed, whole antibodies, their dimers, individual light and heavy chains, other forms of immunoglobulin, or antigen-binding fragments can be purified according to standardized technical procedures, including sulfate precipitation. Petition 870210013044, dated 08 / 02 / 2021, pages 97 / 205 In the 87 / 190 recombinant production procedure, the antibodies or immunoglobulin chains encoded by the polynucleotide may be glycosylated or non-glycosylated. Antibodies or the corresponding immunoglobulin chains may also include an initial methionine amino acid residue.

[00199] In some embodiments, after a vector has been incorporated into a suitable host, the host can be maintained under conditions suitable for high-level expression of the nucleotide sequences and, as desired, the collection and purification of immunoglobulin light chains, heavy chains, light / heavy chain dimers or intact antibodies, antigen-binding fragments or other forms of immunoglobulin can follow; see Beychok, “Cells of Immunoglobulin Synthesis”, Academic Press, NY, (1979). In this way, polynucleotides or vectors are introduced into cells which, in turn, produce the antibody or antigen-binding fragments. In addition, transgenic animals, preferably mammals, comprising the aforementioned host cells, can be used for the large-scale production of the antibody or antibody fragments.

[00200] Transformed host cells can be grown in fermenters and cultured using any appropriate techniques to achieve optimal cell growth. Once expressed, whole antibodies, their dimers, individual light and heavy chains, other forms of immunoglobulin, or antigen-binding fragments can be purified according to standardized technical procedures, including sulfate precipitation. Petition 870210013044, dated 08 / 02 / 2021, pages 97 / 205 88 / 190 ammonium, affinity columns, column chromatography, gel electrophoresis and the like; see, Scopes, “Protein Purification”, Springer Verlag, NY (1982). The antibody or antigen-binding fragments can then be isolated from the growth medium, cell lysates or cell membrane fractions. The isolation and purification, for example, of microbially expressed antibodies or antigen-binding fragments can be by any conventional means such as, for example, preparative chromatographic separations and immunological separations, such as those involving the use of monoclonal or polyclonal antibodies directed, for example, against the constant region of the antibody.

[00201] Aspects of the development are related to a hybridoma, which provides an indefinitely prolonged source of monoclonal antibodies. As an alternative to obtaining immunoglobulins directly from hybridoma culture, immortalized hybridoma cells can be used as a source of rearranged heavy chain and light chain loci for subsequent expression and / or genetic manipulation. Rearranged antibody genes can be reverse transcribed from appropriate mRNAs to produce cDNA. In some embodiments, the constant region of the heavy chain can be exchanged for that of a different isotype or eliminated completely. Variable regions can be linked to encode single-stranded Fv regions. Multiple Fv regions can be linked to confer binding ability to more than one target, or chimeric combinations of heavy and light chains can be employed.Any appropriate method can be used for cloning variable antibody regions and generating antibodies. Petition 870210013044, dated 08 / 02 / 2021, pages 98 / 205 88 / 190 ammonium, affinity columns, column chromatography, gel electrophoresis and the like; see, Scopes, “Protein Purification”, Springer Verlag, NY (1982). The antibody or antigen-binding fragments can then be isolated from the growth medium, cell lysates or cell membrane fractions. The isolation and purification, for example, of microbially expressed antibodies or antigen-binding fragments can be by any conventional means such as, for example, preparative chromatographic separations and immunological separations, such as those involving the use of monoclonal or polyclonal antibodies directed, for example, against the constant region of the antibody.

[00201] Aspects of the development are related to a hybridoma, which provides an indefinitely prolonged source of monoclonal antibodies. As an alternative to obtaining immunoglobulins directly from hybridoma culture, immortalized hybridoma cells can be used as a source of rearranged heavy chain and light chain loci for subsequent expression and / or genetic manipulation. Rearranged antibody genes can be reverse transcribed from appropriate mRNAs to produce cDNA. In some embodiments, the constant region of the heavy chain can be exchanged for that of a different isotype or eliminated completely. Variable regions can be linked to encode single-stranded Fv regions. Multiple Fv regions can be linked to confer binding ability to more than one target, or chimeric combinations of heavy and light chains can be employed.Any appropriate method can be used for cloning variable antibody regions and generating antibodies. Petition 870210013044, dated 08 / 02 / 2021, pages 98 / 205 89 / 190 recombinants.

[00202] In some embodiments, an appropriate nucleic acid encoding variable regions of a heavy and / or light chain is obtained and inserted into expression vectors that can be transfected into standardized recombinant host cells. Several such host cells can be used. In some embodiments, mammalian host cells may be advantageous for efficient processing and production. Typical mammalian cell lines useful for this purpose include CHO cells, 293 cells, or NSO cells. Production of the antibody or antigen-binding fragment can be effected by culturing a modified recombinant host under culture conditions appropriate for host cell growth and coding sequence expression. Antibodies or antigen-binding fragments can be recovered by isolating them from the culture.Expression systems can be designed to include signaling peptides so that the resulting antibodies are secreted into the environment; however, intracellular production is also possible.

[00203] The disclosure also includes a polynucleotide encoding at least one variable region of an immunoglobulin chain of the antibodies described in this descriptive report. In some embodiments, the variable region encoded by the polynucleotide comprises at least one complementarity-determining region (CDR) of the VH and / or VL of the antibody variable region produced by any of the hybridomas described above.

[00204] Antibody-coding polynucleotides or Petition 870210013044, dated 08 / 02 / 2021, pages 99 / 205 89 / 190 recombinants.

[00202] In some embodiments, an appropriate nucleic acid encoding variable regions of a heavy and / or light chain is obtained and inserted into expression vectors that can be transfected into standardized recombinant host cells. Several such host cells can be used. In some embodiments, mammalian host cells may be advantageous for efficient processing and production. Typical mammalian cell lines useful for this purpose include CHO cells, 293 cells, or NSO cells. Production of the antibody or antigen-binding fragment can be effected by culturing a modified recombinant host under culture conditions appropriate for host cell growth and coding sequence expression. Antibodies or antigen-binding fragments can be recovered by isolating them from the culture.Expression systems can be designed to include signaling peptides so that the resulting antibodies are secreted into the environment; however, intracellular production is also possible.

[00203] The disclosure also includes a polynucleotide encoding at least one variable region of an immunoglobulin chain of the antibodies described in this descriptive report. In some embodiments, the variable region encoded by the polynucleotide comprises at least one complementarity-determining region (CDR) of the VH and / or VL of the antibody variable region produced by any of the hybridomas described above.

[00204] Antibody-coding polynucleotides or Petition 870210013044, dated 08 / 02 / 2021, pages 99 / 205 90 / 190 antigen-binding fragments may be, for example, DNA, cDNA, RNA, or synthetically produced DNA or RNA, or a recombinantly produced chimeric nucleic acid molecule comprising any of those polynucleotides alone or in combination. In some embodiments, a polynucleotide is part of a vector. These vectors may further comprise genes, such as marker genes, that allow selection of the vector in a suitable host cell under suitable conditions.

[00205] In some embodiments, a polynucleotide is operatively linked to expression control sequences that allow expression in prokaryotic or eukaryotic cells. Polynucleotide expression comprises the transcription of the polynucleotide into a translatable mRNA. Regulatory elements that ensure expression in eukaryotic cells, preferably mammalian cells, are well known to those skilled in the art. They may include regulatory sequences that facilitate transcription initiation and, optionally, poly-A signals that facilitate transcription termination and transcript stabilization. Additional regulatory elements may include transcription enhancers as well as translation enhancers, and / or naturally associated or heterologous promoter regions. Possible regulatory elements that allow expression in prokaryotic host cells include, for example, the PL, Lac, Trp, or Tac promoter in E.E. coli, and examples of regulatory elements that allow expression in eukaryotic host cells are the AOX1 or GAL1 promoter in yeast, or the CMV promoter, SV40 promoter, RSV (Rous sarcoma virus) promoter, enhancer. Petition 870210013044, dated 08 / 02 / 2021, pages 100 / 205 90 / 190 antigen-binding fragments may be, for example, DNA, cDNA, RNA, or synthetically produced DNA or RNA, or a recombinantly produced chimeric nucleic acid molecule comprising any of those polynucleotides alone or in combination. In some embodiments, a polynucleotide is part of a vector. These vectors may further comprise genes, such as marker genes, that allow selection of the vector in a suitable host cell under suitable conditions.

[00205] In some embodiments, a polynucleotide is operatively linked to expression control sequences that allow expression in prokaryotic or eukaryotic cells. Polynucleotide expression comprises the transcription of the polynucleotide into a translatable mRNA. Regulatory elements that ensure expression in eukaryotic cells, preferably mammalian cells, are well known to those skilled in the art. They may include regulatory sequences that facilitate transcription initiation and, optionally, poly-A signals that facilitate transcription termination and transcript stabilization. Additional regulatory elements may include transcription enhancers as well as translation enhancers, and / or naturally associated or heterologous promoter regions. Possible regulatory elements that allow expression in prokaryotic host cells include, for example, the PL, Lac, Trp, or Tac promoter in E.E. coli, and examples of regulatory elements that allow expression in eukaryotic host cells are the AOX1 or GAL1 promoter in yeast, or the CMV promoter, SV40 promoter, RSV (Rous sarcoma virus) promoter, enhancer. Petition 870210013044, dated 08 / 02 / 2021, pages 100 / 205 91 / 190 of CMV, SV40 enhancer or a globin intron in mammalian cells and other animal cells.

[00206] In addition to the elements responsible for initiating transcription, these regulatory elements may also include transcription termination signals, for example, the SV40-poly-A site or the tk-poly-A site, downstream of the polynucleotide. Furthermore, depending on the expression system employed, leader sequences capable of directing the polypeptide to a cellular compartment or secreting it into the medium may be added to the coding sequence of the polynucleotide and have been previously described. The leader sequence (or sequences) is assembled in the appropriate phase with translation, initiation, and termination sequences and, preferably, a leader sequence capable of directing the secretion of the translated protein, or a portion thereof, for example, into the extracellular medium.Optionally, a heterologous polynucleotide sequence encoding a fusion protein that includes a C- or N-terminal identification peptide that transmits the desired characteristics, for example, stabilization or simplified purification of the expressed recombinant product, may be used.

[00207] In some embodiments, polynucleotides encoding at least the variable domain of the light and / or heavy chain may encode the variable domains of both immunoglobulin chains or only one. Similarly, the polynucleotides may be under the control of the same promoter or may be controlled separately for expression. In addition, some aspects are related to the vectors, particularly plasmids, cosmids, viruses, and bacteriophages conventionally used in engineering. Petition 870210013044, dated 08 / 02 / 2021, pages 101 / 205 91 / 190 of CMV, SV40 enhancer or a globin intron in mammalian cells and other animal cells.

[00206] In addition to the elements responsible for initiating transcription, these regulatory elements may also include transcription termination signals, for example, the SV40-poly-A site or the tk-poly-A site, downstream of the polynucleotide. Furthermore, depending on the expression system employed, leader sequences capable of directing the polypeptide to a cellular compartment or secreting it into the medium may be added to the coding sequence of the polynucleotide and have been previously described. The leader sequence (or sequences) is assembled in the appropriate phase with translation, initiation, and termination sequences and, preferably, a leader sequence capable of directing the secretion of the translated protein, or a portion thereof, for example, into the extracellular medium.Optionally, a heterologous polynucleotide sequence encoding a fusion protein that includes a C- or N-terminal identification peptide that transmits the desired characteristics, for example, stabilization or simplified purification of the expressed recombinant product, may be used.

[00207] In some embodiments, polynucleotides encoding at least the variable domain of the light and / or heavy chain may encode the variable domains of both immunoglobulin chains or only one. Similarly, the polynucleotides may be under the control of the same promoter or may be controlled separately for expression. In addition, some aspects are related to the vectors, particularly plasmids, cosmids, viruses, and bacteriophages conventionally used in engineering. Petition 870210013044, dated 08 / 02 / 2021, pages 101 / 205 92 / 190 genetics comprising a polynucleotide encoding a variable domain of an antibody immunoglobulin chain or antigen-binding fragment; optionally in combination with a polynucleotide encoding the variable domain of the other antibody immunoglobulin chain.

[00208] In some embodiments, expression control sequences are provided as eukaryotic promoter systems in vectors capable of transforming or transfecting eukaryotic host cells, but control sequences for prokaryotic hosts can also be used. Expression vectors derived from viruses such as, for example, retroviruses, vaccinia virus, adeno-associated virus, herpesvirus, or bovine papillomavirus, can be used for the delivery of polynucleotides or vector into a target cell population (e.g., to genetically modify a cell to express an antibody or antigen-binding fragment). Several appropriate methods can be used for the construction of recombinant viral vectors. In some embodiments, polynucleotides and vectors can be reconstituted in liposomes for delivery to target cells.Vectors containing polynucleotides (e.g., the heavy and / or light variable domain(s) of immunoglobulin chains encoding sequences and expression control sequences) can be transferred to the host cell by appropriate methods, which vary depending on the type of cell host. Modifications

[00209] Antibodies or antigen-binding fragments of the revelation can be modified with a marker. Petition 870210013044, dated 08 / 02 / 2021, pages 102 / 205 92 / 190 genetics comprising a polynucleotide encoding a variable domain of an antibody immunoglobulin chain or antigen-binding fragment; optionally in combination with a polynucleotide encoding the variable domain of the other antibody immunoglobulin chain.

[00208] In some embodiments, expression control sequences are provided as eukaryotic promoter systems in vectors capable of transforming or transfecting eukaryotic host cells, but control sequences for prokaryotic hosts can also be used. Expression vectors derived from viruses such as, for example, retroviruses, vaccinia virus, adeno-associated virus, herpesvirus, or bovine papillomavirus, can be used for the delivery of polynucleotides or vector into a target cell population (e.g., to genetically modify a cell to express an antibody or antigen-binding fragment). Several appropriate methods can be used for the construction of recombinant viral vectors. In some embodiments, polynucleotides and vectors can be reconstituted in liposomes for delivery to target cells.Vectors containing polynucleotides (e.g., the heavy and / or light variable domain(s) of immunoglobulin chains encoding sequences and expression control sequences) can be transferred to the host cell by appropriate methods, which vary depending on the type of cell host. Modifications

[00209] Antibodies or antigen-binding fragments of the revelation can be modified with a marker. Petition 870210013044, dated 08 / 02 / 2021, pages 102 / 205 93 / 190 detectable, including, without limitation, an enzyme, prosthetic group, fluorescent material, luminescent material, bioluminescent material, radioactive material, positron-emitting metal, non-radioactive paramagnetic metal ion, and affinity marker for detection and isolation of latent promyostatin / myostatin. The detectable substance may be coupled or conjugated directly to the developing polypeptides or indirectly, via an intermediate (such as, for example, a linker) using suitable techniques. Non-limiting examples of suitable enzymes include horseradish peroxidase, alkaline phosphatase, β-galactosidase, glucose oxidase, or acetylcholinesterase; non-limiting examples of suitable prosthetic group complexes include streptavidin / biotin and avidin / biotin;Non-limiting examples of suitable fluorescent materials include biotin, umbelliferone, fluorescein, fluorescein isothiocyanate, rhodamine, fluorescein dichlorotriazinylamine, dansyl chloride or phycoerythrin; an example of a luminescent material includes luminol; non-limiting examples of bioluminescent materials include luciferase, luciferin and aquorin; Examples of suitable radioactive material include a radioactive metal ion, for example, alpha emitters or other radioisotopes such as, for example, iodine (131I,125I,123I,121I), carbon (14C), sulfur (35S), tritium (3H), indium (115mIn,113mIn,112In,mIn), and technetium (99Tc,99mTc), thallium (201Ti), gallium (68Ga, 67Ga), palladium (103Pd), molybdenum (99Mo), xenon (133Xe), fluorine (18F), 153Sm; Lu159Gd,149Pm,140La,175Yb,166Ho,90Y,47Sc,86R,188Re,142Pr,105Rh,97Ru,68Ge,57Co,65Zn,85Sr,32P,153Gd,169Yb,51Cr,54Mn,75Se and tin (113Sn,117Sn). The detectable substance may be Petition 870210013044, dated 08 / 02 / 2021, pp. 103 / 205 93 / 190 detectable, including, without limitation, an enzyme, prosthetic group, fluorescent material, luminescent material, bioluminescent material, radioactive material, positron-emitting metal, non-radioactive paramagnetic metal ion, and affinity marker for detection and isolation of latent promyostatin / myostatin. The detectable substance may be coupled or conjugated directly to the developing polypeptides or indirectly, via an intermediate (such as, for example, a linker) using suitable techniques. Non-limiting examples of suitable enzymes include horseradish peroxidase, alkaline phosphatase, β-galactosidase, glucose oxidase, or acetylcholinesterase; non-limiting examples of suitable prosthetic group complexes include streptavidin / biotin and avidin / biotin;Non-limiting examples of suitable fluorescent materials include biotin, umbelliferone, fluorescein, fluorescein isothiocyanate, rhodamine, fluorescein dichlorotriazinylamine, dansyl chloride or phycoerythrin; an example of a luminescent material includes luminol; non-limiting examples of bioluminescent materials include luciferase, luciferin and aquorin; Examples of suitable radioactive material include a radioactive metal ion, for example, alpha emitters or other radioisotopes such as, for example, iodine (131I,125I,123I,121I), carbon (14C), sulfur (35S), tritium (3H), indium (115mIn,113mIn,112In,1nIn), and technetium (99Tc,99mTc), thallium (201Ti), gallium (68Ga, 67Ga), palladium (103Pd), molybdenum (99Mo), xenon (133Xe), fluorine (18F), 153Sm; Lu159Gd,149Pm,140La,175Yb,166Ho,90Y,47Sc,86R,188Re,142Pr,105Rh,97Ru,68Ge,57Co,65Zn,85Sr,32P,153Gd,169Yb,51Cr,54Mn,75Se and tin (113Sn,117Sn). The detectable substance may be Petition 870210013044, dated 08 / 02 / 2021, pages 103 / 205 94 / 190 coupled or conjugated directly to anti-promyostatin / latent myostatin antibodies of the detection or indirectly, through an intermediary (such as, for example, a linker) with the use of appropriate techniques. Anti-promyostatin / latent myostatin antibodies conjugated to a detectable substance can be used for diagnostic assays, as described in this descriptive report. Pharmaceutical compositions

[00210] One or more of the anti-promyostatin / latent myostatin antibodies may be mixed with a pharmaceutically acceptable carrier (excipient), including buffer, to form a pharmaceutical composition for use in the relief of a disease or disorder that is associated with myopathy. The term “acceptable” means that the carrier must be compatible with the active ingredient of the composition (and preferably capable of stabilizing the active ingredient) and not deleterious to the individual being treated. Examples of pharmaceutically acceptable excipients (carriers), including buffers, would be obvious to those skilled in the art and have been previously described. See, for example, “Remington: The Science and Practice of Pharmacy”, 20th Edition (2000) Lippincott Williams and Wilkins, Ed. KE Hoover.In one example, a pharmaceutical composition described in this descriptive report contains more than one anti-promyostatin / latent myostatin antibody that recognizes different epitopes / residues of the target antigen.

[00211] The pharmaceutical compositions to be used in the present methods may comprise pharmaceutically acceptable carriers, excipients or stabilizers in the form of Petition 870210013044, dated 08 / 02 / 2021, pages 104 / 205 94 / 190 coupled or conjugated directly to anti-promyostatin / latent myostatin antibodies of the detection or indirectly, through an intermediary (such as, for example, a linker) with the use of appropriate techniques. Anti-promyostatin / latent myostatin antibodies conjugated to a detectable substance can be used for diagnostic assays, as described in this descriptive report. Pharmaceutical compositions

[00210] One or more of the anti-promyostatin / latent myostatin antibodies may be mixed with a pharmaceutically acceptable carrier (excipient), including buffer, to form a pharmaceutical composition for use in the relief of a disease or disorder that is associated with myopathy. The term “acceptable” means that the carrier must be compatible with the active ingredient of the composition (and preferably capable of stabilizing the active ingredient) and not deleterious to the individual being treated. Examples of pharmaceutically acceptable excipients (carriers), including buffers, would be obvious to those skilled in the art and have been previously described. See, for example, “Remington: The Science and Practice of Pharmacy”, 20th Edition (2000) Lippincott Williams and Wilkins, Ed. KE Hoover.In one example, a pharmaceutical composition described in this descriptive report contains more than one anti-promyostatin / latent myostatin antibody that recognizes different epitopes / residues of the target antigen.

[00211] The pharmaceutical compositions to be used in the present methods may comprise pharmaceutically acceptable carriers, excipients or stabilizers in the form of Petition 870210013044, dated 08 / 02 / 2021, pages 104 / 205 95 / 190 lyophilized formulations or aqueous solutions (“Remington: The Science and Practice of Pharmacy, 20th Edition (2000) Lippincott Williams and Wilkins, Ed. KE Hoover). Acceptable carriers, excipients or stabilizers are non-toxic to receptors at the dosages and concentrations used, and may include buffers such as, for example, phosphate, citrate and other organic acids; antioxidants, including ascorbic acid and methionine; preservatives (e.g., octadecyldimethylbenzyl ammonium chloride; hexamethonium chloride; benzalkonium chloride, benzethonium chloride; phenol, butyl or benzyl alcohol; alkyl parabens such as, for example, methyl or propyl paraben; catechol; resorcinol; cyclohexanol; 3-pentanol; and m-cresol); low molecular weight polypeptides (less than about 10 residues); proteins, for example, serum albumin, gelatin or immunoglobulins; hydrophilic polymers such as, for example, polyvinylpyrrolidone;Amino acids such as, for example, glycine, glutamine, asparagine, histidine, arginine, or lysine; monosaccharides, disaccharides, and other carbohydrates, including glucose, mannose, or dextrans; chelating agents such as, for example, EDTA; sugars such as, for example, sucrose, mannitol, trehalose, or sorbitol; salt-forming counter-ions such as, for example, sodium; metal complexes (e.g., Zn-protein complexes); and / or non-ionic surfactants such as, for example, TWEEN™, PLURONICS™, or polyethylene glycol (PEG). Pharmaceutically acceptable excipients are further described in this descriptive report.

[00212] In some examples, the pharmaceutical composition described in this descriptive report comprises liposomes Petition 870210013044, dated 08 / 02 / 2021, pages 105 / 205 95 / 190 lyophilized formulations or aqueous solutions (“Remington: The Science and Practice of Pharmacy, 20th Edition (2000) Lippincott Williams and Wilkins, Ed. KE Hoover). Acceptable carriers, excipients or stabilizers are non-toxic to receptors at the dosages and concentrations used, and may include buffers such as, for example, phosphate, citrate and other organic acids; antioxidants, including ascorbic acid and methionine; preservatives (e.g., octadecyldimethylbenzyl ammonium chloride; hexamethonium chloride; benzalkonium chloride, benzethonium chloride; phenol, butyl or benzyl alcohol; alkyl parabens such as, for example, methyl or propyl paraben; catechol; resorcinol; cyclohexanol; 3-pentanol; and m-cresol); low molecular weight polypeptides (less than about 10 residues); proteins, for example, serum albumin, gelatin or immunoglobulins; hydrophilic polymers such as, for example, polyvinylpyrrolidone;Amino acids such as, for example, glycine, glutamine, asparagine, histidine, arginine, or lysine; monosaccharides, disaccharides, and other carbohydrates, including glucose, mannose, or dextrans; chelating agents such as, for example, EDTA; sugars such ...

Claims

1. An antibody or an antigen-binding fragment thereof characterized by comprising a variable region of the heavy chain consisting of the amino acid sequence of SEQ ID NO: 25 and a variable region of the light chain consisting of the amino acid sequence of SEQ ID NO: 31, wherein the antibody or an antigen-binding fragment thereof binds specifically to promyostatin or latent myostatin.

2. An antibody or an antigen-binding fragment thereof, according to claim 1, characterized in that the antibody or antigen-binding fragment thereof comprises a heavy chain consisting of the amino acid sequence of SEQ ID NO: 50 and / or a light chain consisting of the amino acid sequence of SEQ ID NO:

51.

3. An antibody or an antigen-binding fragment thereof, according to claim 1, characterized in that the heavy chain of the antibody or antigen-binding fragment comprises an N-terminal pyroglutamic acid residue and the light chain of the antibody or antigen-binding fragment comprises an N-terminal pyroglutamic acid residue.

4. An antibody or an antigen-binding fragment thereof, according to any one of claims 1 to 3, characterized in that the antibody or antigen-binding fragment thereof is a human or humanized antibody or antigen-binding fragment thereof.

5. An antibody or an antigen-binding fragment thereof, according to any one of claims 1 to 4, characterized in that the antibody or antigen-binding fragment thereof comprises a constant IgG4 domain. Petition 870260028601, dated 03 / 26 / 2026, page 12 / 18 2 / 3 6. An antibody or an antigen-binding fragment thereof, according to any one of claims 1 to 5, characterized in that the antibody or antigen-binding fragment thereof inhibits the proteolytic formation of mature myostatin by a tolloid protease.

7. An antibody or an antigen-binding fragment thereof, according to claim 6, characterized in that the antibody or antigen-binding fragment thereof inhibits the proteolytic formation of mature myostatin by a tolloid protease with an IC50 less than 1 μM, and / or has cross-reactivity with human and murine promyostatin or latent myostatin.

8. In vitro method for reducing myostatin receptor activation in cells present in a medium comprising promyostatin or latent myostatin, characterized by comprising delivering to the medium the antibody or antigen-binding fragment thereof, as defined in any one of claims 1 to 7, in an amount effective to inhibit the proteolytic activation of promyostatin or latent myostatin.

9. Pharmaceutical composition characterized by comprising the antibody or antigen-binding fragment thereof, as defined in any one of claims 1 to 7, and a pharmaceutically acceptable carrier.

10. Pharmaceutical composition, according to claim 9, characterized in that it is a lyophilized composition, a liquid or frozen composition.

11. Pharmaceutical composition, according to claim 10, characterized in that the composition is frozen at a temperature less than or equal to -65°C.

12. Pharmaceutical composition, according to any one of claims 9 to 11, characterized in that the pharmaceutically acceptable carrier comprises histidine.

13. Syringe characterized by comprising the pharmaceutical composition as defined in any one of claims 9 to 12.

14. Nucleic acid encoding an antibody or an antigen-binding fragment thereof, characterized by comprising a variable region of the heavy chain consisting of the nucleic acid sequence SEQ ID NO: 39 and a variable region of the light chain consisting of the nucleic acid sequence SEQ ID NO: 45.

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